Long-term retrospective study on the placement of the cementless acetabular cup and clinical outcomes in patients undergoing femoral head autografting for hip dysplasia and total hip arthroplasty.

PubMed

Ozden, Vahit Emre; Dikmen, Goksel; Beksac, Burak; Tozun, Ismail Remzi

2018-05-01

Placement of acetabular cup in the dysplastic hip is a challenging procedure. Using bulk femoral head autograft to increase the bony coverage of the cup is one of the techniques, which have been described. The impact of cup position on cup and autograft survival is a controversial issue. We aimed to determine whether the position of cementless acetabular cup used in conjunction with femoral head autograft in dysplastic hips affected the autograft-host incorporation with its final radiographic appearance and the cup survivorship into the second decade. Thirty-eight dysplastic hips with varying Crowe types in 31 patients (30 women and one man) were included. The mean age was 47 years (range, 29-64 years) and the mean follow-up was 20.3 years (range, 14.8-25.9 years). The initial postoperative and final radiographs were evaluated. The survival rate of the cups was analysed using Kaplan-Meier statistics and the log-rank test. Multivariate analysis was used to evaluate the effect of variables (Crowe type, radiographic initial host bone coverage over the cup and position of the cup) on survivorship. The acetabular cups were positioned anatomical in 27/38 hips according to Ranawat measurement technique. Trabecular bridging at graft-host interface was seen in all cases at an average 22.1 months. Neither acetabular cup position nor initial host bone coverage over acetabular cup less than 50% had any significant effect on either cup survival or final radiographic appearance of the graft. The 20-year cup survival rate without aseptic revision was 66% (95 CI, 52%-84%). No revision was performed due to graft resorption. Twenty-year survival rate of the cementless cup combination with femoral head autograft showed no significant differences whether it was placed at high or anatomic hip centre. The final radiographic appearance of the autograft was not affected from either the cup location or the initial radiographic horizontal host bone coverage. Copyright © 2018 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Initial stability of cementless acetabular cups: press-fit and screw fixation interaction--an in vitro biomechanical study.

PubMed

Tabata, Tomonori; Kaku, Nobuhiro; Hara, Katsutoshi; Tsumura, Hiroshi

2015-04-01

Press-fit and screw fixation are important technical factors to achieve initial stability of a cementless acetabular cup for good clinical results of total hip arthroplasty. However, how these factors affect one another in initial cup fixation remains unclear. Therefore, this study aimed to evaluate the mutual influence between press-fit and screw fixation on initial cup stability. Foam bone was subjected to exact hemispherical-shape machining to diameters of 48, 48.5 and 49 mm. A compressive force was applied to ensure seating of a 48-mm-diameter acetabular cup in the foam bone prior to testing. Screws were inserted in six different conditions and tightened in a radial direction at the same torque strength. Then, the socket was rotated with a twist-testing machine, and the torque value at the start of axial rotation between the socket and the foam bone was measured under each screw condition. The torque values for the 48-mm-diameter reaming were >20 N m higher than those for the 48.5- and 49-mm-diameter reaming in each screw condition, indicating that press-fit fixation is stronger than screw fixation. Meanwhile, torque values for the 48.5- and 49-mm-diameter reaming tended to increase with increasing the number of screws. According to our experiment, press-fit fixation of a cementless acetabular cup achieved rigid stability. Although the supplemental screws increased stability of the implant under good press-fit conditions, they showed little impact on whole-cup stability. In the case of insufficient press-fit fixation, cup stability depends on screw stability and increasing the number of additional screws increases cup stability.

Modern dual-mobility cup implanted with an uncemented stem: about 100 cases with 12-year follow-up.

PubMed

Philippot, Remi; Meucci, Jean Francois; Boyer, Bertrand; Farizon, Frederic

2013-09-01

We report the results of a 12-year follow-up retrospective series of 100 total hip arthroplasties using cementless, press-fit, dual-mobility acetabular cups. The aim of our study was to evaluate the clinical and radiographic results of this acetabular cup at last follow-up. This continuous and homogeneous series included 100 primary total hip arthroplasties performed during the year 2000. The THA combined a Corail® stem (Corail®, Depuy, Warsaw, IN) with a stainless steel Novae Sunfit® (Serf, Decines, France) acetabular cup. Fifteen patients died and 2 were lost to follow-up. Two cases of early dislocation were observed, and 3 cases of aseptic loosening of the acetabular component were reported. The mean stem subsidence was 0.71 mm, the mean craniopodal acetabular migration was 1.37 mm, and the mean medio-lateral acetabular migration was 1.52 mm. The 12-year survivorship is comparable to the data from the literature. The low dislocation rate at 12 years confirms the long-term, high stability of dual mobility, which should be recommended in primary THA for patients at risk for postoperative instability. The absence of true intraprosthetic dislocation events at 12-year follow-up provides evidence of the good quality of the latest generation of polyethylene liners and the necessity of combining thin-mirror, polished femoral necks with dual-mobility cups.

Outcome after cementless total hip arthroplasty for arthritic hip in patients with residual poliomyelitis: a case series.

PubMed

Cho, Yoon J; Lee, Choong H; Chun, Young S; Rhyu, Kee H

2016-09-29

In this case series, we investigated the outcome of cementless total hip arthroplasty (THA) for advanced hip osteoarthritis in patients with residual poliomyelitis to evaluate its clinical usefulness for these patients. 11 unilateral cementless primary THA were performed to arthritic hips in patients with residual poliomyelitis. 7 were in paralytic and 4 were in nonparalytic limbs. The mean follow-up duration was 79.9 months. Retrospective clinical evaluations with various scores and radiological evaluations were made. Harris Hip Score, Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Short-form (SF)-36 physical scales were significantly improved after the surgery. However, UCLA activity score and SF-36 mental scale were not. Because of remaining leg length discrepancies, all but 1 noted a residual limp. In nonparalytic hip, functional acetabular cup inclination during weight bearing significantly increased from installed inclination. Other than 1 case of posterior dislocation, no complications were observed. Although the overall result itself is excellent, THA for these patients cannot improve limp, physical activity and mental status. Surgeons should be aware of the change of the inclination of acetabular cup during mobilisation, especially for THA in contralateral hip.

Cementless total hip arthroplasty with a double chevron subtrochanteric shortening osteotomy in patients with Crowe type-IV hip dysplasia.

PubMed

Li, Xigong; Sun, Junying; Lin, Xiangjin; Xu, Sanzhong; Tang, Tiansi

2013-06-01

The authors describe a modified double chevron subtrochanteric shortening osteotomy combined with cementless total hip arthroplasty for Crowe type-IV hip dysplasia. Shortening the femur allows to relax the shortened musculature. This operation was performed in 18 patients (22 hips) between January 2000 and February 2006. The mean follow-up period was 5.6 years (range: 3 to 8 years). The mean amount of femoral subtrochanteric shortening was 38 mm (range: 25 to 60 mm). The mean Harris hip score improved from 47 (range: 35 to 65) preoperatively to 88 points (range: 75 to 97) at final follow-up. The Trendelenburg sign was corrected from positive to negative in 12 of 22 hips. No acetabular or femoral components loosened or required revision during the follow-up period. All osteotomy sites healed in 3 to 6 months without complications. Cementless total hip arthroplasty using the modified double chevron subtrochanteric osteotomy provided good short- to midterm results in all 22 Crowe type-IV hip dislocations. Moreover, it restored the anatomic hip center and the limb length, which contributed to correction of the preoperative limp.

In vivo implant fixation of carbon fiber-reinforced PEEK hip prostheses in an ovine model.

PubMed

Nakahara, Ichiro; Takao, Masaki; Bandoh, Shunichi; Bertollo, Nicky; Walsh, William R; Sugano, Nobuhiko

2013-03-01

Carbon fiber-reinforced polyetheretherketone (CFR/PEEK) is theoretically suitable as a material for use in hip prostheses, offering excellent biocompatibility, mechanical properties, and the absence of metal ions. To evaluate in vivo fixation methods of CFR/PEEK hip prostheses in bone, we examined radiographic and histological results for cementless or cemented CFR/PEEK hip prostheses in an ovine model with implantation up to 52 weeks. CFR/PEEK cups and stems with rough-textured surfaces plus hydroxyapatite (HA) coatings for cementless fixation and CFR/PEEK cups and stems without HA coating for cement fixation were manufactured based on ovine computed tomography (CT) data. Unilateral total hip arthroplasty was performed using cementless or cemented CFR/PEEK hip prostheses. Five cementless cups and stems and six cemented cups and stems were evaluated. On the femoral side, all cementless stems demonstrated bony ongrowth fixation and all cemented stems demonstrated stable fixation without any gaps at both the bone-cement and cement-stem interfaces. All cementless cases and four of the six cemented cases showed minimal stress shielding. On the acetabular side, two of the five cementless cups demonstrated bony ongrowth fixation. Our results suggest that both cementless and cemented CFR/PEEK stems work well for fixation. Cup fixation may be difficult for both cementless and cemented types in this ovine model, but bone ongrowth fixation on the cup was first seen in two cementless cases. Cementless fixation can be achieved using HA-coated CFR/PEEK implants, even under load-bearing conditions. Copyright © 2012 Orthopaedic Research Society.

Bone remodelling around HA-coated acetabular cups

PubMed Central

Nielsen, P. T.; Søballe, K.

2006-01-01

This study was designed to investigate bone remodelling around the cup in cementless THA. Previous studies indicate an advantage of better sealing of the bone-prosthesis interface by HA/TCP coating of implants, inhibiting polyethylene-induced osteolysis. One hundred patients gave informed consent to participate in a controlled randomized study between porous coated Trilogy versus Trilogy Calcicoat (HA/TCP coated). The cup was inserted in press-fit fixation. The femoral component was a cementless porous coated titanium alloy stem (Bi-Metric), with a modular 28-mm CrCo head. The Harris Hip Score (HHS) and bone mineral density (BMD) determined by DEXA scanning were used to study the effect. Measurements revealed no difference between the two groups after 3 years either in the clinical outcome or in terms of periprosthetic bone density. Patients with a body mass index above normal regained more bone mineral than patients with normal weight. This finding supports the assumption that load is beneficial to bone remodelling. PMID:16761153

The effect of dynamic hip motion on the micromotion of press-fit acetabular cups in six degrees of freedom.

PubMed

Crosnier, Emilie A; Keogh, Patrick S; Miles, Anthony W

2016-08-01

The hip joint is subjected to cyclic loading and motion during activities of daily living and this can induce micromotions at the bone-implant interface of cementless total hip replacements. Initial stability has been identified as a crucial factor to achieve osseointegration and long-term survival. Whilst fixation of femoral stems achieves good clinical results, the fixation of acetabular components remains a challenge. In vitro methods assessing cup stability keep the hip joint in a fixed position, overlooking the effect of hip motion. The effect of hip motion on cup micromotion using a hip motion simulator replicating hip flexion-extension and a six degrees of freedom measurement system was investigated. The results show an increase in cup micromotion under dynamic hip motion compared to Static Flexion. This highlights the need to incorporate hip motion and measure all degrees of freedom when assessing cup micromotion. In addition, comparison of two press-fit acetabular cups with different surface coatings suggested similar stability between the two cups. This new method provides a basis for a more representative protocol for future pre-clinical evaluation of different cup designs. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Bilateral non-traumatic acetabular and femoral neck fractures due to pregnancy-associated osteoporosis.

PubMed

Aynaci, Osman; Kerimoglu, Servet; Ozturk, Cagatay; Saracoglu, Metehan

2008-03-01

Pregnancy-associated osteoporosis is a rare disorder and its pathophysiology remains unknown. We report a case of pregnancy-associated osteoporosis in a 27-year-old primiparous patient who revealed bilateral hip pain during early postnatal period. The plain radiographs and computerized tomography showed bilateral femoral neck and acetabular fractures. The diagnosis of osteoporosis was established by bone mineral density. Diagnostic work-up excluded a secondary osteoporosis. The case was treated successfully by bilateral cementless total hip arthroplasty. Bone mineral density increased after 2 years of treatment with calcium-vitamin D, calcitriol and alendronate. Diagnosis of pregnancy-associated osteoporosis should be suspected when hip pain occurs during pregnancy or in the post-partum period as it can lead to acetabular and femoral neck fractures.

Development of an acoustic measurement protocol to monitor acetabular implant fixation in cementless total hip Arthroplasty: A preliminary study.

PubMed

Goossens, Quentin; Leuridan, Steven; Henyš, Petr; Roosen, Jorg; Pastrav, Leonard; Mulier, Michiel; Desmet, Wim; Denis, Kathleen; Vander Sloten, Jos

2017-11-01

In cementless total hip arthroplasty (THA), the initial stability is obtained by press-fitting the implant in the bone to allow osseointegration for a long term secondary stability. However, finding the insertion endpoint that corresponds to a proper initial stability is currently based on the tactile and auditory experiences of the orthopedic surgeon, which can be challenging. This study presents a novel real-time method based on acoustic signals to monitor the acetabular implant fixation in cementless total hip arthroplasty. Twelve acoustic in vitro experiments were performed on three types of bone models; a simple bone block model, an artificial pelvic model and a cadaveric model. A custom made beam was screwed onto the implant which functioned as a sound enhancer and insertor. At each insertion step an acoustic measurement was performed. A significant acoustic resonance frequency shift was observed during the insertion process for the different bone models; 250 Hz (35%, second bending mode) to 180 Hz (13%, fourth bending mode) for the artificial bone block models and 120 Hz (11%, eighth bending mode) for the artificial pelvis model. No significant frequency shift was observed during the cadaveric experiment due to a lack of implant fixation in this model. This novel diagnostic method shows the potential of using acoustic signals to monitor the implant seating during insertion. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Subsidence of a cementless femoral component influenced by body weight and body mass index.

PubMed

Stihsen, Christoph; Radl, Roman; Keshmiri, Armin; Rehak, Peter; Windhager, Reinhard

2012-05-01

This trial was designed to evaluate the impact of physical characteristics such as body mass index, body weight and height on distal stem migration of a cementless femoral component, as the influence of obesity on the outcome of THA is still debated in literature and conflicting results have been found. In this retrospective cohort study, migration patterns for 102 implants were analysed using the Einzel-Bild-Roentgen-Analyse (EBRA-FCA, femoral component analysis). In all cases the Vision 2000 stem was implanted and combined with the Duraloc acetabular component (DePuy, Warsaw, Indiana). The mean follow-up was 93 months. EBRA-FCA evaluations revealed a mean subsidence of 1.38 mm after two years, 2.06 mm after five and 2.24 mm after seven years. Five stems loosened aseptically. Correlation between increased migration over the whole period and aseptic loosening was highly significant (p < 0.001). Surgical technique had a significant influence on migration and stem stability (p = 0.002) but physical patient characteristics such as body weight over 75 kg and height over 165 cm also significantly influenced stem subsidence towards progressive migration (p = 0.001, p < 0.001). However, a high BMI did not trigger progressive stem migration (p = 0.87). Being of the male gender raised the odds for increased migration (p = 0.03). Physical characteristics such as body weight and height showed significant influence on migration patterns of this cementless femoral component. The operating surgeon should be aware that body weight above 75 kg and height over 165 cm may trigger increased stem migration and the surgeon should aim to fit these prostheses as tightly as possible. However this study demonstrates that a high BMI does not trigger progressive stem migration. Further investigations are needed to confirm our findings.

Low Frequency of Early Complications With Dual-mobility Acetabular Cups in Cementless Primary THA.

PubMed

Chughtai, Morad; Mistry, Jaydev B; Diedrich, Aloise M; Jauregui, Julio J; Elmallah, Randa K; Bonutti, Peter M; Harwin, Steven F; Malkani, Arthur L; Kolisek, Frank R; Mont, Michael A

2016-10-01

Dislocation complicates 1% to 5% of primary total hip arthroplasties (THAs). As a result, some surgeons consider dual-mobility articulations, which are usually used in the revision setting to decrease the likelihood of dislocation, as an option for primary THA. However, few studies have evaluated their use in this setting. (1) What is the cup survivorship when the dual-mobility articulation is used in the setting of primary THA? (2) What are the clinical outcomes with this approach? (3) What are the radiographic outcomes? (4) What are the complications of dual-mobility articulations in primary THA? Between 2011 and 2013, the five participating surgeons performed 495 cementless primary THAs. During that time, one of the five surgeons used dual-mobility articulations for all THAs, and the other four used it whenever the acetabular cup size was 52 mm or greater to enable a 28-mm head. Of the 495 patients, 453 (92%) were performed using this device. Smaller patients were treated with a standard THA. Of the 453 patients, a total of 43 patients (10%) were lost to followup before the 2-year minimum. The resulting 410 patients who were included in the analysis (164 men, 246 women) had a mean age of 64 years (SD, 12 years). The mean followup was 3 years (SD, 0.7 years). We performed Kaplan-Meier analyses to assess survivorship to aseptic failure and all-cause acetabular component survivorship. Clinical outcomes were evaluated using the Harris hip score (HHS); radiographs were assessed for cup migration, progressive radiolucencies, and positional changes of the components; and any surgery-related complications were recorded. The survivorship to aseptic failure and all-cause acetabular component survivorship was 99.8% (failures, n = 1) (95% confidence interval [CI], 4.517-4.547) and 99.3% (failures, aseptic, n = 1; septic, n = 2) (95% CI, 4.494-4.543); one hip had trunnion notching caused by impingement of a malpositioned cup, which was treated with revision of the cup and stem; and two patients had periprosthetic infections that were treated with two-stage revisions. There were no dislocations. Patients had a mean HHS of 94 (SD, 6) at final followup. On radiographic evaluation, no progressive radiolucencies or positional changes of the components were identified. Surgical complications included one traumatic avulsion of the abductors, one traumatic avulsion of the greater trochanter, which was repaired without revision of any of the components, and one loose femoral stem, which required revision of the femoral component only. Dual-mobility cups in primary THA yield seemingly comparable survivorship and complications to conventional THA bearings at short-term followup. Because serious complications have occasionally been reported with the use of these bearings, larger, longer term, comparative-and ideally, randomized-trials will be needed to establish the superiority of one approach over the other. Until or unless such studies show the superiority of dual-mobility designs for primary THA, we recommend that in the setting of uncomplicated primary THA, dual-mobility articulations be used only in centers that track their results carefully or in research protocols. Level IV, therapeutic study.

Possible Vascular Injury Due to Screw Eccentricity in Minimally Invasive Total Hip Arthroplasty.

PubMed

Singh, Nishant Kumar; Rai, Sanjay Kumar; Rastogi, Amit

2017-01-01

Vascular injury during minimally invasive total hip arthroplasty (THA) is uncommon, yet a well-recognized and serious issue. It emerges because of non-visibility of vascular structures proximal to the pelvic bone during reaming, drilling holes, and fixing of screws. Numerous studies have found that screw fixation during cementless THA is beneficial for the initial stability of cup; yet, no anatomical guidelines support angular eccentric screw fixation. In this study, we obtained the pelvic arterial-phase computed tomographic data of thirty eight humans and reconstructed the three-dimensional models of osseous and vessel structures. We performed the surgical simulation to fix these structures with cementless cups and screws with angular eccentricities. The effect of screw eccentricities (angular eccentricities of ±17° and ±34°) on the vascular injury was determined. Measurement between screw and adjoining vessels was performed and analyzed statistically to ascertain a comparative risk study for blood vessels that are not visible during surgery. Authors similarly discussed the significant absence of appreciation of quadrant systems proposed by Wasielewski et al . on eccentric screws. Adjustment of quadrant systems provided by Wasielewski et al . is required for acetabular implants with eccentric holes for fixation of acetabular screws.

A cemented cup with acetabular impaction bone grafting is more cost-effective than an uncemented cup in patients under 50 years.

PubMed

Busch, Vincent J J F; Verschueren, Joost; Adang, Eddy M; Lie, Stein A; Havelin, Leif I; Schreurs, Berend W

2016-01-01

Acetabular deficiencies in young patients can be restored in several ways during total hip arthroplasty. Currently, cementless cups are most frequently used. Impaction bone grafting of acetabular defects is a more biological approach, but is it cost-effective in young patients on the long term? We designed a decision model for a cost-utility analysis of a cemented cup with acetabular impaction bone grafting versus an uncemented cup, in terms of cost per quality-adjusted life year (QALY) for the young adult with acetabular bone deficiency, in need for a primary total hip arthroplasty. Outcome probabilities and effectiveness were derived from the Radboud University Nijmegen Medical Centre and the Norwegian Hip Register. Multiple sensitivity analyses were used to assess the contribution of the included variables in the model's outcome. Cemented cups with impaction bone grafting were more cost-effective compared to the uncemented option in terms of costs per QALY. A scenario suggesting equal primary survival rates of both cemented and uncemented cups still showed an effect gain of the cemented cup with impaction bone grafting, but at higher costs. Based on this model, the first choice of treatment of the acetabular bone deficient osteoarthritic hip in a young patient is reconstruction with impaction bone grafting and a cemented cup.

Midterm Outcomes of Revision Total Hip Arthroplasty With the Use of a Multihole Highly-Porous Titanium Shell.

PubMed

Delanois, Ronald E; Gwam, Chukwuweike U; Mohamed, Nequesha; Khlopas, Anton; Chughtai, Morad; Malkani, Arthur L; Mont, Michael A

2017-09-01

We are reporting on the minimum 5-year outcomes of patients who underwent revision total hip arthroplasty (THA) using a specific highly-porous titanium shell. We assessed (1) aseptic and all-cause survivorship; (2) functional outcomes; (3) complications; and (4) radiographic outcomes. Two hospital databases were evaluated for patients who underwent revision THA due to component instability or aseptic loosening using a cementless highly-porous titanium shell between September 2006 and December 2011. This yielded 35 patients who had a mean age of 61 years (range 14-88 years). Patients had a mean follow-up of 6 years (minimum 5 years). All-cause and aseptic survivorship of the shell was calculated. Functional outcomes were assessed using the Harris Hip Score. We determined the incidence of postoperative complications and performed radiographic evaluation of pelvic radiographs from regular office visits. The aseptic survivorship of the acetabular component was 97% (95% confidence interval; 8.1-9.5). The all-cause survivorship of the acetabular component was 91% (95% confidence interval; 7.3-8.1). One patient had an aseptic failure and 2 patients had septic failures. The mean postoperative Harris Hip Score was 76 points (range, 61-91 points). Excluding the aseptic and septic failures, there was no osteolysis or progressive radiolucencies present on radiographic evaluation at final follow-up. At a minimum of 5-year follow-up, the highly-porous titanium acetabular revision shell has excellent survivorship and functional outcomes. Although long-term follow-up is needed to further monitor these implants, the results are promising and demonstrate that this prosthesis may be an excellent option for patients undergoing revision THA. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of bearing friction torques on the primary stability of press-fit acetabular cups: A novel in vitro method.

PubMed

Alexander, Jahnke; Stefan, Schroeder; Alfonso, Fonseca Ulloa Carlos; Adam, Ahmed Gafar; Alexander, Ishaque Bernd; Markus, Rickert

2018-05-10

Aseptic loosening is the main reason for revision of total hip arthroplasty, and relative micromotions between cementless acetabular cups and bone play an important role regarding their comparatively high loosening rate. Therefore, the aim of the present study was to analyze the influence of resulting frictional torques on the primary stability of press-fit acetabular cups subjected to two different bearing partners. A cementless press-fit cup was implanted in bone-like foam. Primary stability of the cup was analyzed by determining spatial total, translational and rotational interface micromotions by means of an eddy current sensor measuring system. Torque transmission into the cup was realized by three synchronous servomotors considering resultant friction torques based on constant friction for ceramic-on-ceramic (CoC: µ = 0.044; max. resultant torque: 1.5 Nm) and for ceramic-on-polyethylene (CoP: µ = 0.063; max. resultant torque: 1.9 Nm) bearing partners. Rotational micromotion of CoC was 8.99 ± 0.85µm and of CoP 13.39 ± 1.43µm. Translational micromotion of CoC was 29.93 ± 1.44µm and of CoP 39.91 ± 2.25µm. Maximum total relative micromotions were 37.10 ± 1.07µm for CoC and 51.64 ± 2.18µm for CoP. Micromotions resulting from CoC were statistically lower than those resulting from CoP (p < 0.05). The described 3D-measuring set-up offers a novel in vitro method of measuring primary stability of acetabular cups. We can therefore conclude, that primary stability of acetabular cup systems can be observed using either the lower friction curve (CoC) or the higher friction curve (CoP). In future studies different cup designs or cup fixation mechanisms may be tested and compared in vitro and assessed prior to implantation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Possible Vascular Injury Due to Screw Eccentricity in Minimally Invasive Total Hip Arthroplasty

PubMed Central

Singh, Nishant Kumar; Rai, Sanjay Kumar; Rastogi, Amit

2017-01-01

Background: Vascular injury during minimally invasive total hip arthroplasty (THA) is uncommon, yet a well-recognized and serious issue. It emerges because of non-visibility of vascular structures proximal to the pelvic bone during reaming, drilling holes, and fixing of screws. Numerous studies have found that screw fixation during cementless THA is beneficial for the initial stability of cup; yet, no anatomical guidelines support angular eccentric screw fixation. Materials and Methods: In this study, we obtained the pelvic arterial-phase computed tomographic data of thirty eight humans and reconstructed the three-dimensional models of osseous and vessel structures. We performed the surgical simulation to fix these structures with cementless cups and screws with angular eccentricities. Results: The effect of screw eccentricities (angular eccentricities of ±17° and ±34°) on the vascular injury was determined. Measurement between screw and adjoining vessels was performed and analyzed statistically to ascertain a comparative risk study for blood vessels that are not visible during surgery. Conclusion: Authors similarly discussed the significant absence of appreciation of quadrant systems proposed by Wasielewski et al. on eccentric screws. Adjustment of quadrant systems provided by Wasielewski et al. is required for acetabular implants with eccentric holes for fixation of acetabular screws. PMID:28790474

Single-stage Acetabular Revision During Two-stage THA Revision for Infection is Effective in Selected Patients.

PubMed

Fink, Bernd; Schlumberger, Michael; Oremek, Damian

2017-08-01

The treatment of periprosthetic infections of hip arthroplasties typically involves use of either a single- or two-stage (with implantation of a temporary spacer) revision surgery. In patients with severe acetabular bone deficiencies, either already present or after component removal, spacers cannot be safely implanted. In such hips where it is impossible to use spacers and yet a two-stage revision of the prosthetic stem is recommended, we have combined a two-stage revision of the stem with a single revision of the cup. To our knowledge, this approach has not been reported before. (1) What proportion of patients treated with single-stage acetabular reconstruction as part of a two-stage revision for an infected THA remain free from infection at 2 or more years? (2) What are the Harris hip scores after the first stage and at 2 years or more after the definitive reimplantation? Between June 2009 and June 2014, we treated all patients undergoing surgical treatment for an infected THA using a single-stage acetabular revision as part of a two-stage THA exchange if the acetabular defect classification was Paprosky Types 2B, 2C, 3A, 3B, or pelvic discontinuity and a two-stage procedure was preferred for the femur. The procedure included removal of all components, joint débridement, definitive acetabular reconstruction (with a cage to bridge the defect, and a cemented socket), and a temporary cemented femoral component at the first stage; the second stage consisted of repeat joint and femoral débridement and exchange of the femoral component to a cementless device. During the period noted, 35 patients met those definitions and were treated with this approach. No patients were lost to followup before 2 years; mean followup was 42 months (range, 24-84 months). The clinical evaluation was performed with the Harris hip scores and resolution of infection was assessed by the absence of clinical signs of infection and a C-reactive protein level less than 10 mg/L. All patients were assessed before surgery, between stages, every 3 months during the first year after surgery, every 6 months during the second year postoperative, and at latest followup, and were retrospectively drawn from a longitudinally maintained institutional database. Thirty-four of 35 patients (97.2%; 95% CI, 85.4%-99.5%) appeared free of infection by criteria of Masri et al. and Zimmerli et al. at latest followup. The Harris hip score was 61 ± 13 points after the first operation and 82 ± 16 points 2 years after the second operation. This technique is a promising treatment option for periprosthetic infections of the hip in which substantial acetabular defects exclude implantation of a normal spacer and a two-stage revision of the femoral component is favored. Level IV, therapeutic study.

Radiographic Underestimation of In Vivo Cup Coverage Provided by Total Hip Arthroplasty for Dysplasia.

PubMed

Nie, Yong; Wang, HaoYang; Huang, ZeYu; Shen, Bin; Kraus, Virginia Byers; Zhou, Zongke

2018-01-01

The accuracy of using 2-dimensional anteroposterior pelvic radiography to assess acetabular cup coverage among patients with developmental dysplasia of the hip after total hip arthroplasty (THA) remains unclear in retrospective clinical studies. A group of 20 patients with developmental dysplasia of the hip (20 hips) underwent cementless THA. During surgery but after acetabular reconstruction, bone wax was pressed onto the uncovered surface of the acetabular cup. A surface model of the bone wax was generated with 3-dimensional scanning. The percentage of the acetabular cup that was covered by intact host acetabular bone in vivo was calculated with modeling software. Acetabular cup coverage also was determined from a postoperative supine anteroposterior pelvic radiograph. The height of the hip center (distance from the center of the femoral head perpendicular to the inter-teardrop line) also was determined from radiographs. Radiographic cup coverage was a mean of 6.93% (SD, 2.47%) lower than in vivo cup coverage for these 20 patients with developmental dysplasia of the hip (P<.001). However, both methods yielded highly correlated measurements for cup coverage (Pearson r=0.761, P<.001). The size of the acetabular cup (P=.001) but not the position of the hip center (high vs normal) was significantly associated with the difference between radiographic and in vivo cup coverage. Two-dimensional radiographically determined cup coverage conservatively reflects in vivo cup coverage and remains an important index (taking 7% underestimation errors and the effect of greater underestimation of larger cup size into account) for assessing the stability of the cup and monitoring for adequate ingrowth of bone. [Orthopedics. 2018; 41(1):e46-e51.]. Copyright 2017, SLACK Incorporated.

Fixation method does not affect restoration of rotation center in hip replacements: A single-site retrospective study

PubMed Central

2012-01-01

Background Aseptic loosening is one of the greatest problems in hip replacement surgery. The rotation center of the hip is believed to influence the longevity of fixation. The aim of this study was to compare the influence of cemented and cementless cup fixation techniques on the position of the center of rotation because cemented cup fixation requires the removal of more bone for solid fixation than the cementless technique. Methods We retrospectively compared pre- and post-operative positions of the hip rotation center in 25 and 68 patients who underwent artificial hip replacements in our department in 2007 using cemented or cementless cup fixation, respectively, with digital radiographic image analysis. Results The mean horizontal and vertical distances between the rotation center and the acetabular teardrop were compared in radiographic images taken pre- and post-operatively. The mean horizontal difference was −2.63 mm (range: -11.00 mm to 10.46 mm, standard deviation 4.23 mm) for patients who underwent cementless fixation, and −2.84 mm (range: -10.87 to 5.30 mm, standard deviation 4.59 mm) for patients who underwent cemented fixation. The mean vertical difference was 0.60 mm (range: -20.15 mm to 10.00 mm, standard deviation 3.93 mm) and 0.41 mm (range: -9.26 mm to 6.54 mm, standard deviation 3.58 mm) for the cementless and cemented fixation groups, respectively. The two fixation techniques had no significant difference on the position of the hip rotation center in the 93 patients in this study. Conclusions The hip rotation center was similarly restored using either the cemented or cementless fixation techniques in this patient cohort, indicating that the fixation technique itself does not interfere with the position of the center of rotation. To completely answer this question further studies with more patients are needed. PMID:22686355

Two-Stage Cementless Revision Total Hip Arthroplasty for Infected Primary Hip Arthroplasties.

PubMed

Camurcu, Yalkin; Sofu, Hakan; Buyuk, Abdul Fettah; Gursu, Sarper; Kaygusuz, Mehmet Akif; Sahin, Vedat

2015-09-01

The main purpose of the present study was to analyze the clinical features, the most common infective agents, and the results of two-stage total hip revision using a teicoplanin-impregnated spacer. Between January 2005 and July 2011, 41 patients were included. At the clinical status analysis, physical examination was performed, Harris hip score was noted, isolated microorganisms were recorded, and the radiographic evaluation was performed. The mean Harris hip score was improved from 38.9 ± 9.6 points to 81.8 ± 5.8 points (P<0.05). Infection was eradicated in 39 hips. Radiographic evidence of stability was noted in 37 acetabular revision components, and all femoral stems. Two-stage revision of the infected primary hip arthroplasty is a time-consuming but a reliable procedure with high rates of success. Copyright © 2015 Elsevier Inc. All rights reserved.

Minimum ten-year results of primary bipolar hip arthroplasty for degenerative arthritis of the hip.

PubMed

Pellegrini, Vincent D; Heiges, Bradley A; Bixler, Brian; Lehman, Erik B; Davis, Charles M

2006-08-01

Bipolar hip arthroplasty has been advocated by some as an alternative to total hip arthroplasty for the treatment of degenerative arthritis of the hip. We sought to assess the results of this procedure at our institution after a minimum duration of follow-up of ten years. We retrospectively reviewed a consecutive series of 152 patients (173 hips) who underwent primary bipolar hemiarthroplasty for the treatment of symptomatic degenerative arthritis of the hip with a cementless femoral component between 1983 and 1987. Of the original cohort of 152 patients, ninety-two patients (104 hips) were available for clinical and radiographic review at a mean of 12.2 years postoperatively. At the time of the latest follow-up, self-administered Harris hip questionnaires were used to assess pain, mobility, activity level, and overall satisfaction with the procedure. Biplanar hip radiographs were made to evaluate bipolar shell migration, osteolysis, and femoral stem fixation. At the time of the latest follow-up, nineteen patients (nineteen hips) had undergone revision to total hip arthroplasty because of mechanical failure, and three patients (three hips) were awaiting revision because of symptomatic radiographic mechanical failure. Twelve acetabular revisions were performed or scheduled for the treatment of pelvic osteolysis or protrusio acetabuli secondary to component migration. Acetabular reconstruction required bone-grafting, an oversized shell, and/or a pelvic reconstruction ring. The overall rate of mechanical failure was 21.2% (twenty-two of 104 hips), with 91% (twenty) of the twenty-two failures involving the acetabular component. Reaming of the acetabulum at the time of the index arthroplasty was associated with a 6.4-fold greater risk of revision. The rate of implant survival, with revision because of mechanical failure as the end point, was 94.2% for femoral components and 80.8% for acetabular components at a mean of 12.2 years. Of the remaining sixty-nine patients (eighty-one hips) in whom the original prosthesis was retained, seventeen patients (24.6%) rated the pain as moderate to severe. Nearly 30% of patients with an intact prosthesis required analgesics on a regular basis. Radiographs were available for fifty-eight hips (including all of the hips with moderate to severe pain) after a minimum duration of follow-up of ten years; twenty-eight of these fifty-eight hips had radiographic evidence of acetabular component migration. This bipolar cup, when used for hemiarthroplasty in patients with symptomatic arthritis of the hip, was associated with unacceptably high rates of pain, migration, osteolysis, and the need for revision to total hip arthroplasty, especially when the acetabulum had been reamed. To the extent that these findings can be generalized to similar implant designs with conventional polyethylene, we do not recommend bipolar hemiarthroplasty as the primary operative treatment for degenerative arthritis of the hip.

Do screws and screw holes affect osteolysis in cementless cups using highly crosslinked polyethylene? A 7 to 10-year follow-up case-control study.

PubMed

Taniguchi, N; Jinno, T; Takada, R; Koga, D; Ando, T; Okawa, A; Haro, H

2018-05-01

The use of screws and the presence of screw holes may cause acetabular osteolysis and implant loosening in cementless total hip arthroplasty (THA) using conventional polyethylene. In contrast, this issue is not fully understood using highly crosslinked polyethylene (HXLPE), particularly in large comparative study. Therefore, we performed a case-control study to assess the influence of screw usage and screw holes on: (1) implant fixation and osteolysis and (2) polyethylene steady-state wear rate, using cases with HXLPE liners followed up for 7-10 years postoperatively. The screw usage and screw holes adversely affect the implant fixation and incidence of wear-related osteolysis in THA with HXLPE. We reviewed 209 primary cementless THAs performed with 26-mm cobalt-chromium heads on HXLPE liners. To compare the effects of the use of screws and the presence of screw holes, the following groups were established: (1) with-screw (n=140); (2) without-screw (n=69); (3) no-hole (n=27) and (4) group in which a cup with screw holes, but no screw was used (n=42). Two adjunct groups (no-hole cups excluded) were established to compare the differences in the two types of HXLPE: (5) remelted group (n=100) and (6) annealed group (n=82). Implant stability and osteolysis were evaluated by plain radiography and computed tomography. The wear rate from 1 year to the final evaluation was measured using plain X-rays and PolyWare Digital software. All cups and stems achieved bony fixation. On CT-scan, no acetabular osteolysis was found, but there were 3 cases with a small area of femoral osteolysis. The mean steady-state wear rate of each group was (1) 0.031±0.022, (2) 0.033±0.035, (3) 0.031±0.024, (4) 0.029±0.018, (5) 0.030±0.018 and (6) 0.034±0.023mm/year, respectively. A comparison of the effects of screw usage or screw holes found no significant between-group differences in the implant stability, prevalence of osteolysis [no acetabular osteolysis and 3/209 at femoral side (1.4%)] and steady-state wear rate. This study suggests that there are no adverse effects on the results of THA with HXLPE from the use of cups with screw holes and the use of screws for cup fixation. Level III retrospective case-control study. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Risk factors for unsuccessful acetabular press-fit fixation at primary total hip arthroplasty.

PubMed

Brulc, U; Antolič, V; Mavčič, B

2017-11-01

Surgeon at primary total hip arthroplasty sometimes cannot achieve sufficient cementless acetabular press-fit fixation and must resort to other fixation methods. Despite a predominant use of cementless cups, this issue is not fully clarified, therefore we performed a large retrospective study to: (1) identify risk factors related to patient or implant or surgeon for unsuccessful intraoperative press-fit; (2) check for correlation between surgeons' volume of operated cases and the press-fit success rate. Unsuccessful intra-operative press-fit more often occurs in older female patients, particular implants, due to learning curve and low-volume surgeons. Retrospective observational cohort of prospectively collected intraoperative data (2009-2016) included all primary total hip arthroplasty patients with implant brands that offered acetabular press-fit fixation only. Press-fit was considered successful if acetabulum was of the same implant brand as the femoral component without additional screws or cement. Logistic regression models for unsuccessful acetabular press-fit included patients' gender/age/operated side, implant, surgeon, approach (posterior n=1206, direct-lateral n=871) and surgery date (i.e. learning curve). In 2077 patients (mean 65.5 years, 1093 females, 1163 right hips), three different implant brands (973 ABG-II™-Stryker, 646 EcoFit™ Implantcast, 458 Procotyl™ L-Wright) were implanted by eight surgeons. Their unsuccessful press-fit fixation rates ranged from 3.5% to 23.7%. Older age (odds ratio 1.01 [95% CI: 0.99-1.02]), female gender (2.87 [95% CI: 2.11-3.91]), right side (1.44 [95% CI: 1.08-1.92]), surgery date (0.90 [95% CI: 1.08-1.92]) and particular implants were significant risk factors only in three surgeons with less successful surgical technique (higher rates of unsuccessful press-fit with Procotyl™-L and EcoFit™ [P=0.01]). Direct-lateral hip approach had a lower rate of unsuccessful press-fit than posterior hip approach (P<0.01), but there was no correlation between surgeons' volume and rate of successful press-fit (Spearman's rho=0.10, P=0.82). Subcohort of 961 patients with 5-7-years follow-up indicated higher early/late cup revision rates with unsuccessful press-fit. Success of press-fit fixation depends entirely on the surgeon and surgical approach. With proper operative technique, the unsuccessful press-fit fixation rate should be below 5% and the impact of patients' characteristics or implants on press-fit fixation is then insignificant. Findings of huge variability in operative technique between surgeons of the presented study emphasize the need for surgeon-specific data stratification in arthroplasty studies and indicate the possibility of false attribution of clinically observed phenomena to patient-related factors in pooled data of large centers or hip arthroplasty registers. Level III, retrospective observational case control study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Increased risk of revision of cementless stemmed total hip arthroplasty with metal-on-metal bearings

PubMed Central

Pedersen, Alma B; Mäkelä, Keijo; Eskelinen, Antti; Havelin, Leif Ivar; Furnes, Ove; Kärrholm, Johan; Garellick, Göran; Overgaard, Søren

2015-01-01

Background and purpose Data from the national joint registries in Australia and England and Wales have revealed inferior medium-term survivorship for metal-on-metal (MoM) total hip arthroplasty (THA) than for metal-on-polyethylene (MoP) THA. Based on data from the Nordic Arthroplasty Register Association (NARA), we compared the revision risk of cementless stemmed THA with MoM and MoP bearings and we also compared MoM THA to each other. Patients and methods We identified 32,678 patients who were operated from 2002 through 2010 with cementless stemmed THA with either MoM bearings (11,567 patients, 35%) or MoP bearings (21,111 patients, 65%). The patients were followed until revision, death, emigration, or the end of the study period (December 31, 2011), and median follow-up was 3.6 (interquartile range (IQR): 2.4–4.8) years for MoM bearings and 3.4 (IQR: 2.0–5.8) years for MoP bearings. Multivariable regression in the presence of competing risk of death was used to assess the relative risk (RR) of revision for any reason (with 95% confidence interval (CI)). Results The cumulative incidence of revision at 8 years of follow-up was 7.0% (CI: 6.0–8.1) for MoM bearings and 5.1% (CI: 4.7–5.6) for MoP bearings. At 6 years of follow-up, the RR of revision for any reason was 1.5 (CI: 1.3–1.7) for MoM bearings compared to MoP bearings. The RR of revision for any reason was higher for the ASR (adjusted RR = 6.4, CI: 5.0–8.1), the Conserve Plus (adjusted RR = 1.7, CI: 1.1–2.5) and “other” acetabular components (adjusted RR = 2.4, CI: 1.5–3.9) than for MoP THA at 6 years of follow-up. Interpretation At medium-term follow-up, the survivorship for cementless stemmed MoM THA was inferior to that for MoP THA, and metal-related problems may cause higher revision rates for MoM bearings with longer follow-up. PMID:25715878

Removal of a well-fixed cementless femoral stem using a microsagittal saw.

PubMed

Kim, Young-Min; Lim, Soo Taek; Yoo, Jeong Joon; Kim, Hee Joong

2003-06-01

Well-fixed cementless femoral components are troublesome to extract. This article describes a technique to extract a well-fixed cementless stem in which the stem is extracted with a bent microsagittal saw blade after a longitudinal cortical window is made.

Optimal acetabular component orientation estimated using edge-loading and impingement risk in patients with metal-on-metal hip resurfacing arthroplasty.

PubMed

Mellon, Stephen J; Grammatopoulos, George; Andersen, Michael S; Pandit, Hemant G; Gill, Harinderjit S; Murray, David W

2015-01-21

Edge-loading in patients with metal-on-metal resurfaced hips can cause high serum metal ion levels, the development of soft-tissue reactions local to the joint called pseudotumours and ultimately, failure of the implant. Primary edge-loading is where contact between the femoral and acetabular components occurs at the edge/rim of the acetabular component whereas impingement of the femoral neck on the acetabular component's edge causes secondary or contrecoup edge-loading. Although the relationship between the orientation of the acetabular component and primary edge-loading has been identified, the contribution of acetabular component orientation to impingement and secondary edge-loading is less clear. Our aim was to estimate the optimal acetabular component orientation for 16 metal-on-metal hip resurfacing arthroplasty (MoMHRA) subjects with known serum metal ion levels. Data from motion analysis, subject-specific musculoskeletal modelling and Computed Tomography (CT) measurements were used to calculate the dynamic contact patch to rim (CPR) distance and impingement risk for 3416 different acetabular component orientations during gait, sit-to-stand, stair descent and static standing. For each subject, safe zones free from impingement and edge-loading (CPR <10%) were defined and, consequently, an optimal acetabular component orientation was determined (mean inclination 39.7° (SD 6.6°) mean anteversion 14.9° (SD 9.0°)). The results of this study suggest that the optimal acetabular component orientation can be determined from a patient's motion and anatomy. However, 'safe' zones of acetabular component orientation associated with reduced risk of dislocation and pseudotumour are also associated with a reduced risk of edge-loading and impingement. Copyright © 2014 Elsevier Ltd. All rights reserved.

R3 Cup Does Not Have a High Failure Rate in Conventional Bearings: A Minimum of 5-Year Follow-Up.

PubMed

Teoh, Kar H; Whitham, Robert D J; Golding, David M; Wong, Jenny F; Lee, Paul Y F; Evans, Aled R

2018-02-01

The R3 cementless acetabular system was first marketed in Australia and Europe in 2007. Previous papers have shown high failure rates of the R3 cup with up to 24% with metal-on-metal bearing. There are currently no medium term clinical results on this cup. The aim of the study is to review our results of the R3 acetabular cup with conventional bearings with a minimum of 5-year follow-up. Patients who were implanted with the R3 acetabular cup were identified from our center's arthroplasty database. A total of 293 consecutive total hip arthroplasties were performed in 286 patients. The primary outcome was revision. The secondary outcomes were the Oxford Hip Scores (OHS) and radiographic evaluation. The mean age of the patients was 69.4 years. The mean preoperative OHS was 23 (range 10-34) and the mean OHS was 40 (range 33-48) at the final follow-up. Radiological evaluation showed an excellent ARA score in all patients at 5 years. None of the R3 cups showed osteolysis at the final follow-up. There were 3 revisions in our series, of which 2 R3 cups were revised. The risk of revision was 1.11% at 5 years. Our experience of using the R3 acetabular system with conventional bearings showed high survivorship and is consistent with the allocated Orthopaedic Data Evaluation Panel rating of 5A* as rated in 2015 in the United Kingdom. Copyright © 2017 Elsevier Inc. All rights reserved.

Does osteoporosis reduce the primary tilting stability of cementless acetabular cups?

PubMed

von Schulze Pellengahr, Christoph; von Engelhardt, Lars V; Wegener, Bernd; Müller, Peter E; Fottner, Andreas; Weber, Patrick; Ackermann, Ole; Lahner, Matthias; Teske, Wolfram

2015-04-21

Cementless hip cups need sufficient primary tilting stability to achieve osseointegration. The aim of the study was to assess differences of the primary implant stability in osteoporotic bone and in bone with normal bone density. To assess the influence of different cup designs, two types of threaded and two types of press-fit cups were tested. The maximum tilting moment for two different cementless threaded cups and two different cementless press-fit cups was determined in macerated human hip acetabuli with reduced (n=20) and normal bone density (n=20), determined using Q-CT. The tilting moments for each cup were determined five times in the group with reduced bone density and five times in the group with normal bone density, and the respective average values were calculated. The mean maximum extrusion force of the threaded cup Zintra was 5670.5 N (max. tilting moment 141.8 Nm) in bone with normal density and.5748.3 N (max. tilting moment 143.7 Nm) in osteoporotic bone. For the Hofer Imhof (HI) threaded cup it was 7681.5 N (192.0 Nm) in bone with normal density and 6828.9 N (max. tilting moment 170.7 Nm) in the group with osteoporotic bone. The mean maximum extrusion force of the macro-textured press-fit cup Metallsockel CL was 3824.6 N (max. tilting moment 95.6 Nm) in bone with normal and 2246.2 N (max. tilting moment 56.2 Nm) in osteoporotic bone. For the Monoblock it was 1303.8 N (max. tilting moment 32.6 Nm) in normal and 1317 N (max. tilting moment 32.9 Nm) in osteoporotic bone. There was no significance. A reduction of the maximum tilting moment in osteoporotic bone of the ESKA press-fit cup Metallsockel CL was noticed. Results on macerated bone specimens showed no statistically significant reduction of the maximum tilting moment in specimens with osteoporotic bone density compared to normal bone, neither for threaded nor for the press-fit cups. With the limitation that the results were obtained using macerated bone, we could not detect any restrictions for the clinical indication of the examined cementless cups in osteoporotic bone.

Pelvic reconstructions following peri-acetabular bone tumour resections using a cementless ice-cream cone prosthesis with dual mobility cup.

PubMed

Issa, Samir-Pierre; Biau, David; Babinet, Antoine; Dumaine, Valérie; Le Hanneur, Malo; Anract, Philippe

2018-01-27

Despite numerous reconstructive techniques and prosthetic devices, pelvic reconstructions following peri-acetabular malignant tumours resections are highly challenging. In the present study, we describe our experience with the Integra® (Lépine, Genay, France) ice-cream cone prosthesis in such indications. The objective was to assess the mid-term outcomes of this device. Twenty-four patients' chart with peri-acetabular malignant tumours, who underwent types II or II + III peri-acetabular resections according to Enneking and Dunham with subsequent reconstruction using the Integra® prosthesis between February 2009 and February 2015, were reviewed. Seventeen cases were primary surgeries and seven cases were revisions (i.e., failures of previous reconstructions for pelvic tumours). All living patients with the prosthesis implanted were functionally assessed, using the musculoskeletal tumour society (MSTS) and Postel-Merle d'Aubigné (PMA) scores. After a mean follow-up of 49 ± 26 months (range, 8 to 94 months), 21 patients were alive (88%), including 15 patients continuously disease-free (63%). MSTS and PMA scores averaged 72 ± 13% (range, 43 to 87%) and 14.6 ± 2.6 (range, 9 to 18), respectively. Fourteen patients (58%) presented at least one complication during follow-up, including four cases of deep infection (17%), four cases of dislocation (17%), and two mechanical failures (8%). At 5 years, the implant survival rate was 75%. In comparison to previous reconstructive techniques that we used in similar indications, functional and oncologic outcomes were improved with the Integra® implant. However, as commonly observed in pelvic bone tumour surgery, complication rates remain significant. Therapeutic, Level IV-Retrospective Cases Series.

Influence of soft tissue in the assessment of the primary fixation of acetabular cup implants using impact analyses.

PubMed

Bosc, Romain; Tijou, Antoine; Rosi, Giuseppe; Nguyen, Vu-Hieu; Meningaud, Jean-Paul; Hernigou, Philippe; Flouzat-Lachaniette, Charles-Henri; Haiat, Guillaume

2018-06-01

The acetabular cup (AC) implant primary stability is an important determinant for the success of cementless hip surgery but it remains difficult to assess the AC implant fixation in the clinic. A method based on the analysis of the impact produced by an instrumented hammer on the ancillary has been developed by our group (Michel et al., 2016a). However, the soft tissue thickness present around the acetabulum may affect the impact response, which may hamper the robustness of the method. The aim of this study is to evaluate the influence of the soft tissue thickness (STT) on the acetabular cup implant primary fixation evaluation using impact analyses. To do so, different AC implants were inserted in five bovine bone samples. For each sample, different stability conditions were obtained by changing the cavity diameter. For each configuration, the AC implant was impacted 25 times with 10 and 30 mm of soft tissues positioned underneath the sample. The averaged indicator I m was determined based on the amplitude of the signal for each configuration and each STT and the pull-out force was measured. The results show that the resonance frequency of the system increases when the value of the soft tissue thickness decreases. Moreover, an ANOVA analysis shows that there was no significant effect of the value of soft tissue thickness on the values of the indicator I m (F = 2.33; p-value = 0.13). This study shows that soft tissue thickness does not appear to alter the prediction of the acetabular cup implant primary fixation obtained using the impact analysis approach, opening the path towards future clinical trials. Copyright © 2018 Elsevier Ltd. All rights reserved.

Initial mechanical stability of cementless highly-porous titanium tibial components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stone, Timothy Brandon; Amer, Luke D; Warren, Christopher P

Cementless fixation in total knee replacement has seen limited use since reports of early failure surfaced in the late 80s and early 90s. However the emergence of improved biomaterials, particularly porous titanium and tantalum, has led to a renewed interest in developing a cementless tibial component to enhance long-term survivorship of the implants. Cement is commonly employed to minimize micromotion in new implants but represents a weak interface between the implant and bone. The elimination of cement and application of these new biomaterials, which theoretically provide improved stability and ultimate osseointegration, would likely result in greater knee replacement success. Additionally,more » the removal of cement from the procedure would help minimize surgical durations and get rid of the time needed for curing, thereby the chance of infection. The purpose of this biomechanical study was twofold. The first goal was to assess whether vibration analysis techniques can be used to evaluate and characterize initial mechanical stability of cementless implants more accurately than the traditional method of micromotion determination, which employs linear variable differential transducers (LVDTs). Second, an evaluative study was performed to determine the comparative mechanical stability of five designs of cementless tibial components under mechanical loading designed to simulate in vivo forces. The test groups will include a cemented Triathlon Keeled baseplate control group, three different 2-peg cementless baseplates with smooth, mid, and high roughnesses and a 4-peg cement/ess baseplate with mid-roughness.« less

Debonding of porous coating of a threaded acetabular component: retrieval analysis.

PubMed

Łapaj, Łukasz; Markuszewski, Jacek; Rybak, Tomasz; Wierusz-Kozłowska, Małgorzata

2013-01-01

This report presents a case of debonding of plasma sprayed porous titanium coating from a threaded acetabular component which caused aseptic loosening of the implant. Weight bearing after delamination caused abrasive damage of the acetabular shell, and particles of the coating embedded in the acetabular liner. Microscopic examination of periprosthetic tissues showed presence of metal particles and macrophage infiltration. Despite microscopic examination of the retrieved component the cause of debonding remains unclear. Copyright © 2012 Elsevier Ltd. All rights reserved.

Does surface roughness influence the primary stability of acetabular cups? A numerical and experimental biomechanical evaluation.

PubMed

Le Cann, Sophie; Galland, Alexandre; Rosa, Benoît; Le Corroller, Thomas; Pithioux, Martine; Argenson, Jean-Noël; Chabrand, Patrick; Parratte, Sébastien

2014-09-01

Most acetabular cups implanted today are press-fit impacted cementless. Anchorage begins with the primary stability given by insertion of a slightly oversized cup. This primary stability is key to obtaining bone ingrowth and secondary stability. We tested the hypothesis that primary stability of the cup is related to surface roughness of the implant, using both an experimental and a numerical models to analyze how three levels of surface roughness (micro, macro and combined) affect the primary stability of the cup. We also investigated the effect of differences in diameter between the cup and its substrate, and of insertion force, on the cups' primary stability. The results of our study show that primary stability depends on the surface roughness of the cup. The presence of macro-roughness on the peripheral ring is found to decrease primary stability; there was excessive abrasion of the substrate, damaging it and leading to poor primary stability. Numerical modeling indicates that oversizing the cup compared to its substrate has an impact on primary stability, as has insertion force. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Component Position and Metal Ion Levels in Computer-Navigated Hip Resurfacing Arthroplasty.

PubMed

Mann, Stephen M; Kunz, Manuela; Ellis, Randy E; Rudan, John F

2017-01-01

Metal ion levels are used as a surrogate marker for wear in hip resurfacing arthroplasties. Improper component position, particularly on the acetabular side, plays an important role in problems with the bearing surfaces, such as edge loading, impingement on the acetabular component rim, lack of fluid-film lubrication, and acetabular component deformation. There are little data regarding femoral component position and its possible implications on wear and failure rates. The purpose of this investigation was to determine both femoral and acetabular component positions in our cohort of mechanically stable hip resurfacing arthroplasties and to determine if these were related to metal ion levels. One hundred fourteen patients who had undergone a computer-assisted metal-on-metal hip resurfacing were prospectively followed. Cobalt and chromium levels, Harris Hip, and UCLA activity scores in addition to measures of the acetabular and femoral component position and angles of the femur and acetabulum were recorded. Significant changes included increases in the position of the acetabular component compared to the native acetabulum; increase in femoral vertical offset; and decreases in global offset, gluteus medius activation angle, and abductor arm angle (P < .05). Multiple regression analysis found no significant predictors of cobalt and chromium metal ion levels. Femoral and acetabular components placed in acceptable position failed to predict increased metal ion levels, and increased levels did not adversely impact patient function or satisfaction. Further research is necessary to clarify factors contributing to prosthesis wear. Copyright © 2016 Elsevier Inc. All rights reserved.

Tapered stems one-third proximally coated have higher complication rates than cylindrical two-third coated stems in patients with high hip dislocation undergoing total hip arthroplasty with step-cut shortening osteotomy.

PubMed

Ozden, V Emre; Dikmen, G; Beksac, B; Tozun, I Remzi

2017-06-01

The results of cementless stems in total hip arthroplasty (THA) done because of congenital dislocation with step-cut osteotomy is not well known, particularly the influence of the design and the role of extent of porous coating. Therefore we performed a retrospective study to evaluate the mid to long-term results THA performed with a single type acetabular component and different geometry and fixation type stems with ceramic bearings in the setting of step-cut subtrochanteric osteotomy in high hip dislocated (HHD) patients. We asked if the stem type affect the outcomes in terms of (1) intra and postoperative complication rates (2) radiographic outcomes (3) prosthesis survival in step-cut subtrochanteric shortening osteotomy. The type of the stem, whether cylindrical or tapered does not affect the outcome if the femoral canal fit and fill is obtained and the step-cut femoral shortening osteotomy is primarily fixed. Forty-five hips in 35 patients with a mean follow up of 10 years (range, 7-14 years) were evaluated. The single type cementless cup was placed at the level of the true acetabulum, a step-cut shortening femoral osteotomy was performed and reconstruction was performed with two different types of tapered stem in twenty-two hips (Synergy™ and Image™ proximally coated, Smith and Nephew, Menphis, TN, USA) and one type of cylindrical stem (Echelon™ with 2/3 coated, Smith and Nephew, Menphis, TN, USA) in twenty-three hips. Harris hip scores (HHS) and a University of California Los Angeles (UCLA) activity scores were calculated for all patients and successive X-rays were evaluated regarding component loosening and osteolysis, along with complications related to bearing, step-cut osteotomy and stem types. Forty-one hips (91%) had good and excellent clinical outcome according to HHS. The mean UCLA activity scores improved from 3.2±0.6 points (range, 2-4) preoperatively to 6.3 points±0.5 (range, 5-7) at the latest follow-up. The mean femoral shortening was 36±10mm (range, 20-65mm). Four (9%) dislocations were observed. There were five (11%) intra-operative femoral fractures and three (7%) cases of non-union, which were observed in tapered stems. Cylindrical stems had superior neutral alignment primarily. With any stem revision as the end point, cylindrical stems had a higher survival rate (100%) than all tapered stems (82%; 95% confident interval [CI] 77-97%) at ten years. With any revision as the end point, the 10-year survival rate for acetabular component (Reflection-Ceramic Interfit) and for femoral components were 98% (95% CI, 85-99%) and 91% (95% CI, 78-97%), respectively. There were more implant related complications in HHD patients undergoing THA when tapered stems with 1/3 proximal coating were used to reconstruct a step cut osteotomized femur, compared to cylindrical stems 2/3 coated. IV, retrospective study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Have cementless and resurfacing components improved the medium-term results of hip replacement for patients under 60 years of age?

PubMed Central

Mason, James; Baker, Paul; Gregg, Paul J; Porter, Martyn; Deehan, David J; Reed, Mike R

2015-01-01

Background and purpose The optimal hip replacement for young patients remains unknown. We compared patient-reported outcome measures (PROMs), revision risk, and implant costs over a range of hip replacements. Methods We included hip replacements for osteoarthritis in patients under 60 years of age performed between 2003 and 2010 using the commonest brand of cemented, cementless, hybrid, or resurfacing prosthesis (11,622 women and 13,087 men). The reference implant comprised a cemented stem with a conventional polyethylene cemented cup and a standard-sized head (28- or 32-mm). Differences in implant survival were assessed using competing-risks models, adjusted for known prognostic influences. Analysis of covariance was used to assess improvement in PROMs (Oxford hip score (OHS) and EQ5D index) in 2014 linked procedures. Results In males, PROMs and implant survival were similar across all types of implants. In females, revision was statistically significantly higher in hard-bearing and/or small-stem cementless implants (hazard ratio (HR) = 4) and resurfacings (small head sizes (< 48 mm): HR = 6; large head sizes (≥ 48 mm): HR = 5) when compared to the reference cemented implant. In component combinations with equivalent survival, women reported significantly greater improvements in OHS with hybrid implants (22, p = 0.006) and cementless implants (21, p = 0.03) (reference, 18), but similar EQ5D index. For men and women, National Health Service (NHS) costs were lowest with the reference implant and highest with a hard-bearing cementless replacement. Interpretation In young women, hybrids offer a balance of good early functional improvement and low revision risk. Fully cementless and resurfacing components are more costly and do not provide any additional benefit for younger patients. PMID:25285617

In vivo degradation of polyethylene liners after gamma sterilization in air.

PubMed

Kurtz, Steven M; Rimnac, Clare M; Hozack, William J; Turner, Joseph; Marcolongo, Michele; Goldberg, Victor M; Kraay, Matthew J; Edidin, Avram A

2005-04-01

Ultra-high molecular weight polyethylene degrades during storage in air following gamma sterilization, but the extent of in vivo degradation remains unclear. The purpose of this study was to quantify the extent to which the mechanical properties and oxidation of conventional polyethylene acetabular liners treated with gamma sterilization in air change in vivo. Fourteen modular cementless acetabular liners were revised at an average of 10.3 years (range, 5.9 to 13.5 years) after implantation. All liners, which had been machined from GUR 415 resin, had been gamma-sterilized in air; the average shelf life was 0.3 year (range, 0.0 to 0.8 year). After removal, the components were expeditiously frozen to minimize ex vivo changes to the polyethylene prior to characterization. The average duration between freezing and testing was 0.6 year. Mechanical properties and oxidation were measured with use of the small-punch test and Fourier transform infrared spectroscopy, respectively, in the loaded and unloaded regions of the liners. There was substantial regional variation in the mechanical properties and oxidation of the retrieved liners. The ultimate load was observed to vary by >90% near the surface. On the average, the rim and the unloaded bearing showed evidence of severe oxidation near the surface after long-term in vivo aging, but these trends were not typically observed on the loaded bearing surface or near the backside of the liners. The mechanical properties of polyethylene that has been gamma-sterilized in air may decrease substantially in vivo, depending on the location in the liner. The most severe oxidation was observed at the rim, suggesting that the femoral head inhibits access of oxygen-containing body fluids to the bearing surface. This is perhaps why in vivo oxidation has not been associated with clinical performance to date.

[Technology of cementless hip endoprosthetics].

PubMed

Ungethüm, M; Blömer, W

1987-06-01

The success achieved with non-cemented hip arthroplasty depends mainly on the stability of the fixation, the quality of the stabilizing bone being just as important as favourable biomechanical conditions. The results of the intensive research and development with respect to the particular features of a non-cemented hip endoprosthesis can be divided into the following basic categories: Biomechanical aspects with special reference to bone related to the design of the prosthesis; material characteristics, such as fatigue strength, tribology, corrosion resistance, and biocompatibility; and development of new materials and coatings to permit direct bonding of implant and bone. With regard to the stem of hip prostheses, the different design parameters of various types are examined to determine their typical design characteristics, such as bearing surface of the collar, geometry of cross section, anatomically adapted shaping, and surface of the implant forming the contact with the bone. The latter can be divided into macroprofiles and macro- and micro-porous coated surfaces. On the other hand, the methods of cementless fixation of acetabular cups can be primarily divided into conical and spherical screw fixation and pegged fixation with additional macroprofiles of porous surfaces. In a separate study of the biomechanical aspects of screwed sockets, the special importance of socket shape and thread geometry are presented with reference to primary stability and long-term fixation of prostheses.

[A simulative biomechanical experiment on different position of none-cement acetabular components influencing the load distribution around acetabulum].

PubMed

Li, Dongsong; Liu, Jianguo; Li, Shuqiang; Fan, Honghui; Guan, Jikui

2008-02-01

In the present study, a three dimensional finite-element model of the human pelvic was reconstructed, and then, under different acetabular component position (the abduction angle ranges from 30 degrees to 70 degrees and the anteversion ranges from 5 degrees to 30degrees) the load distribution around the acetabular was evaluated by the computer biomechanical analysis program (Solidworks). Through the obtained load distribution results, the most even and reasonable range of the distribution was selected; therefore the safe range of the acetabular component implantation can be validated from the biomechanics aspect.

21 CFR 888.3320 - Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/metal semi-constrained, with a... Devices § 888.3320 Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis. (a) Identification. A hip joint metal/metal semi-constrained, with a cemented acetabular...

21 CFR 888.3320 - Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint metal/metal semi-constrained, with a... Devices § 888.3320 Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis. (a) Identification. A hip joint metal/metal semi-constrained, with a cemented acetabular...

Bone preserving techniques for explanting the well-fixed cemented acetabular component.

PubMed

Stevens, Jarrad; Macpherson, Gavin; Howie, Colin

2018-06-01

Removal of a well-fixed, cemented acetabular component at the time of revision hip surgery can be complex. It is essential to remove the implant and cement mantle in a timely fashion while preserving bone stock and osseous integrity. The biomechanical properties of polymethylmethacrylate cement and polyethylene can be utilised to aid with the removal of well cemented implants which are often harder than the surrounding bone. While removal of loose components may be relatively straightforward, the challenge for the revision arthroplasty surgeon often involves the removal of well-fixed implants. Here, we present three established techniques for the removal of a well-fixed cemented acetabular component and one novel modification we have described before. We collate and review four techniques for removing well-fixed cemented acetabular implants that utilise the different biomechanical properties of bone cement and polyethylene. These techniques are illustrated with a photographic series utilising saw bones. A step-by-step approach to our new technique is shown in photographs, both in the clinical setting and with a "Sawbone". This is accompanied by a clinical video that details the surgical technique in its entirety. These techniques utilise different biomechanical principles to extract the acetabular component. Each technique has advantages and disadvantages. Our new technique is a simplification of a previously published extraction manoeuvre that utilises tensile force between cement and the implant to remove the polyethylene cup. This is a safe and reproducible technique in patients with a well-fixed cemented acetabular implant. Understanding the biomechanical properties of polymethylmethacrylate bone cement and polyethylene can aid in the safe removal of a well-fixed cemented acetabular component in revision hip surgery. The optimal technique for removal of a cemented acetabular component varies depending on a number of patient and implant factors. This summary of the available techniques will be of interest to revision arthroplasty surgeons.

The principle of low frictional torque in the Charnley total hip replacement.

PubMed

Wroblewski, B M; Siney, P D; Fleming, P A

2009-07-01

The design of the Charnley total hip replacement follows the principle of low frictional torque. It is based on the largest possible difference between the radius of the femoral head and that of the outer aspect of the acetabular component. The aim is to protect the bone-cement interface by movement taking place at the smaller radius, the articulation. This is achieved in clinical practice by a 22.225 mm diameter head articulating with a 40 mm or 43 mm diameter acetabular component of ultra-high molecular weight polyethylene. We compared the incidence of aseptic loosening of acetabular components with an outer diameter of 40 mm and 43 mm at comparable depths of penetration with a mean follow-up of 17 years (1 to 40). In cases with no measurable wear none of the acetabular components were loose. With increasing acetabular penetration there was an increased incidence of aseptic loosening which reflected the difference in the external radii, with 1.5% at 1 mm, 8.8% at 2 mm, 9.7% at 3 mm and 9.6% at 4 mm of penetration in favour of the larger 43 mm acetabular component. Our findings support the Charnley principle of low frictional torque. The level of the benefit is in keeping with the predicted values.

Should we worry about periacetabular interference gaps in hip resurfacing?

PubMed

Gomes, Bruno; Olsen, Michael; Donnelly, Michael; Kumar, Ashesh; Schemitsch, Emil H

2013-02-01

Press-fit acetabular component seating in hip resurfacing can be challenging as a strong interference fit is required. It has not been established whether reducing the acetabular underream minimizes incomplete component seating or leads to increased acetabular loosening. We examined (1) the incidence and natural history of postoperative interference gaps in hip resurfacing and (2) whether reduction of the acetabular underream from 2 mm to 1 mm reduces the incidence of periacetabular interference gaps. Of 327 Birmingham Hip™ Resurfacings (Smith & Nephew Inc, Memphis, TN, USA) performed by a single surgeon from 2005 to 2010, we evaluated 306 hips with a minimum 1-year radiographic followup. Postoperative periacetabular interference gaps were monitored for radiographic gap resolution at latest followup. The frequency of incomplete component seating was compared between acetabula prepared with 1- and 2-mm underream techniques. Minimum followup was 1 year (mean, 2.7 years; range, 1-6 years). Fifty-one percent of the postoperative radiographs demonstrated the presence of a periacetabular interference gap. At latest followup, 96% of these gaps were no longer visible. We observed a reduction in the number of interference gaps identified when acetabular preparation changed from a 2-mm underream (63%) to a 1-mm underream (39%). There were no revisions due to acetabular failure. Periacetabular interference gaps were common in this series but not associated with acetabular component failure. The use of a 1-mm underream is sufficient for adequate short-term press-fit fixation of the acetabular component in Birmingham Hip™ Resurfacing arthroplasty. Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

[Ex vivo microCT analysis of possible microfractures of the femoral head during implantation of a cementless hip resurfacing femoral component].

PubMed

Lerch, M; Olender, G; von der Höh, N; Thorey, F; von Lewinski, G; Meyer-Lindenberg, A; Windhagen, H; Hurschler, C

2009-01-01

Microfractures of the femoral head during implantation of the femoral components are suspected to be a cause of fractures at the implant/neck junction which represent a common failure mode in hip resurfacing arthroplasty. Callus formation observed in femoral head retrievals suggests the occurrence of microfractures inside the femoral head, which might be inadvertently caused by the surgeon during implantation. The aim of this biomechanical study was to analyse whether or not the implantation of a cementless femoral component hip resurfacing system causes microfractures in the femoral head. After the preparation of 20 paired human cadaveric femoral heads, the cementless femoral component ESKA Typ BS (ESKA Implants GmbH & Co., Lübeck) was implanted on 9 specimens with an impaction device that generates 4.5 kN impaction force. On 9 specimens the femoral component was implanted by hand. One head was used as a fracture model, 1 specimen served as control without manipulation. The femoral component used for impaction was equipped with hinges to enable its removal without further interfering with the bone stock. Specimens were scanned with a microCT device before and after impaction and the microCT datasets before and after impaction were compared to identify possible microfractures. Twenty strikes per hand or with the impaction device provided sufficient implant seating. Neither the macroscopic examination nor the 2-dimensional microCT analysis revealed any fractures of the femoral heads after impaction. At least macroscopically and in the 2-dimensional microCT analysis, implantation of the cementless hip resurfacing femoral component ESKA Typ BS with 4.5 kN or by hand does not seem to cause fractures of the femoral head. Georg Thieme Verlag KG Stuttgart, New York.

Endoscopic or arthroscopic iliopsoas tenotomy for iliopsoas impingement following total hip replacement. A prospective multicenter 64-case series.

PubMed

Guicherd, W; Bonin, N; Gicquel, T; Gedouin, J E; Flecher, X; Wettstein, M; Thaunat, M; Prevost, N; Ollier, E; May, O

2017-12-01

Impingement between the acetabular component and the iliopsoas tendon is a cause of anterior pain after total hip replacement (THR). Treatment can be non-operative, endoscopic or arthroscopic, or by open revision of the acetabular component. Few studies have assessed these options. The present study hypothesis was that endo/arthroscopic treatment provides rapid pain relief with a low rate of complications. A prospective multicenter study included 64 endoscopic or arthroscopic tenotomies for impingement between the acetabular component and the iliopsoas tendon, performed in 8 centers. Mean follow-up was 8months, with a minimum of 6months and no loss to follow-up. Oxford score, patient satisfaction, anterior pain and iliopsoas strength were assessed at last follow-up. Complications and revision procedures were collated. Forty-four percent of patients underwent rehabilitation. At last follow-up, 92% of patients reported pain alleviation. Oxford score, muscle strength and pain in hip flexion showed significant improvement. The complications rate was 3.2%, with complete resolution. Mean hospital stay was 0.8 nights. In 2 cases, arthroscopy revealed metallosis, indicating revision of the acetabular component. The only predictive factor was acetabular projection on oblique view. Rehabilitation significantly improved muscle strength. Endoscopic or arthroscopic tenotomy for impingement between the acetabular component and the iliopsoas tendon following THR significantly alleviated anterior pain in more than 92% of cases. The low complications rate makes this the treatment of choice in case of failure of non-operative management. Arthroscopy also reorients diagnosis in case of associated joint pathology. Projection of the acetabular component on preoperative oblique view is the most predictive criterion, guiding treatment. Copyright © 2017. Published by Elsevier Masson SAS.

Neck fracture of a cementless forged titanium alloy femoral stem following total hip arthroplasty: a case report and review of the literature

PubMed Central

Grivas, Theodoros B; Savvidou, Olga D; Psarakis, Spyridon A; Bernard, Pierre-Francois; Triantafyllopoulos, George; Kovanis, Ioannis; Alexandropoulos, Panagiotis

2007-01-01

Introduction Fractures of the neck of the femoral component have been reported in uncemented total hip replacements, however, to our knowledge, no fractures of the neck of a cementless forged titanium alloy femoral stem coated in the proximal third with hydroxy-apatite have been reported in the medical literature. Case presentation This case report describes a fracture of the neck of a cementless forged titanium alloy stem coated in the proximal third with hydroxy-apatite. Conclusion The neck of the femoral stem failed from fatigue probably because of a combination of factors described analytically below. PMID:18062807

The jumbo acetabular component for acetabular revision: Curtain Calls and Caveats.

PubMed

Lachiewicz, P F; Watters, T S

2016-01-01

The 'jumbo' acetabular component is now commonly used in acetabular revision surgery where there is extensive bone loss. It offers high surface contact, permits weight bearing over a large area of the pelvis, the need for bone grafting is reduced and it is usually possible to restore centre of rotation of the hip. Disadvantages of its use include a technique in which bone structure may not be restored, a risk of excessive posterior bone loss during reaming, an obligation to employ screw fixation, limited bone ingrowth with late failure and high hip centre, leading to increased risk of dislocation. Contraindications include unaddressed pelvic dissociation, inability to implant the component with a rim fit, and an inability to achieve screw fixation. Use in acetabulae with < 50% bone stock has also been questioned. Published results have been encouraging in the first decade, with late failures predominantly because of polyethylene wear and aseptic loosening. Dislocation is the most common complication of jumbo acetabular revisions, with an incidence of approximately 10%, and often mandates revision. Based on published results, a hemispherical component with an enhanced porous coating, highly cross-linked polyethylene, and a large femoral head appears to represent the optimum tribology for jumbo acetabular revisions. ©2016 The British Editorial Society of Bone & Joint Surgery.

21 CFR 888.3330 - Hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... component is intended to be fixed with bone cement. The acetabular component is intended for use without bone cement (§ 888.3027). (b) Classification. Class III. (c) Date PMA or notice of completion of a PDP...

21 CFR 888.3330 - Hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... component is intended to be fixed with bone cement. The acetabular component is intended for use without bone cement (§ 888.3027). (b) Classification. Class III. (c) Date PMA or notice of completion of a PDP...

21 CFR 888.3330 - Hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... component is intended to be fixed with bone cement. The acetabular component is intended for use without bone cement (§ 888.3027). (b) Classification. Class III. (c) Date PMA or notice of completion of a PDP...

21 CFR 888.3330 - Hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... component is intended to be fixed with bone cement. The acetabular component is intended for use without bone cement (§ 888.3027). (b) Classification. Class III. (c) Date PMA or notice of completion of a PDP...

21 CFR 888.3330 - Hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... component is intended to be fixed with bone cement. The acetabular component is intended for use without bone cement (§ 888.3027). (b) Classification. Class III. (c) Date PMA or notice of completion of a PDP...

Modification of the explant system for the removal of well fixed hip resurfacing sockets.

PubMed

Rawal, Jaikirty S; Soler, J Agustin; Rhee, Jae S; Dobson, Michael H; Konan, Sujith; Haddad, Fares S

2010-10-01

A major concern during revision hip arthroplasty is acetabular bone loss during the extraction of well-fixed acetabular components. Despite the good early survivorship of resurfacing prostheses, revision surgery may be necessary. We recommend the use of the Explant acetabular extraction system (Zimmer, Warsaw, Ind) with a trial liner to preserve acetabular bone stock. We present 2 cases of revised resurfacings using this technique, demonstrating minimal interference to the remaining acetabular bone. Copyright © 2010 Elsevier Inc. All rights reserved.

Does Increased Coefficient of Friction of Highly Porous Metal Increase Initial Stability at the Acetabular Interface?

PubMed

Goldman, Ashton H; Armstrong, Lucas C; Owen, John R; Wayne, Jennifer S; Jiranek, William A

2016-03-01

Highly porous metal acetabular components illustrate a decreased rate of aseptic loosening in short-term follow-up compared with previous registry data. This study compared the effect of component surface roughness at the bone-implant interface and the quality of the bone on initial pressfit stability. The null hypothesis is that a standard porous coated acetabular cup would show no difference in initial stability as compared with a highly porous acetabular cup when subjected to a bending moment. Second, would bone mineral density (BMD) be a significant variable under these test conditions. In a cadaveric model, acetabular cup micromotion was measured during a 1-time cantilever bending moment applied to 2 generations of pressfit acetabular components. BMD data were also obtained from the femoral necks available for associated specimen. The mean bending moment at 150 μm was not found to be significantly different for Gription (24.6 ± 14.0 N m) cups vs Porocoat (25 ± 10.2 N m; P > .84). The peak bending moment tolerated by Gription cups (33.9 ± 20.3 N m) was not found to be significantly different from Porocoat (33.5 ± 12.2 N m; P > .92). No correlation between BMD and bending moment at 150 μm of displacement could be identified. The coefficient of friction provided by highly porous metal acetabular shells used in this study did not provide better resistance to migration under bending load when compared with a standard porous coated component. Copyright © 2016 Elsevier Inc. All rights reserved.

Socket position determines hip resurfacing 10-year survivorship.

PubMed

Amstutz, Harlan C; Le Duff, Michel J; Johnson, Alicia J

2012-11-01

Modern metal-on-metal hip resurfacing arthroplasty designs have been used for over a decade. Risk factors for short-term failure include small component size, large femoral head defects, low body mass index, older age, high level of sporting activity, and component design, and it is established there is a surgeon learning curve. Owing to failures with early surgical techniques, we developed a second-generation technique to address those failures. However, it is unclear whether the techniques affected the long-term risk factors. We (1) determined survivorship for hips implanted with the second-generation cementing technique; (2) identified the risk factors for failure in these patients; and (3) determined the effect of the dominant risk factors on the observed modes of failure. We retrospectively reviewed the first 200 hips (178 patients) implanted using our second-generation surgical technique, which consisted of improvements in cleaning and drying the femoral head before and during cement application. There were 129 men and 49 women. Component orientation and contact patch to rim distance were measured. We recorded the following modes of failure: femoral neck fracture, femoral component loosening, acetabular component loosening, wear, dislocation, and sepsis. The minimum followup was 25 months (mean, 106.5 months; range, 25-138 months). Twelve hips were revised. Kaplan-Meier survivorship was 98.0% at 5 years and 94.3% at 10 years. The only variable associated with revision was acetabular component position. Contact patch to rim distance was lower in hips that dislocated, were revised for wear, or were revised for acetabular loosening. The dominant modes of failure were related to component wear or acetabular component loosening. Acetabular component orientation, a factor within the surgeon's control, determines the long-term success of our current hip resurfacing techniques. Current techniques have changed the modes of failure from aseptic femoral failure to wear or loosening of the acetabular component. Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Total knee replacement-cementless tibial fixation with screws: 10-year results.

PubMed

Ersan, Önder; Öztürk, Alper; Çatma, Mehmet Faruk; Ünlü, Serhan; Akdoğan, Mutlu; Ateş, Yalım

2017-12-01

The aim of this study was to evaluate the long term clinical and radiological results of cementless total knee replacement. A total of 51 knees of 49 patients (33 female and 16 male; mean age: 61.6 years (range, 29-66 years)) who underwent TKR surgery with a posterior stabilized hydroxyapatite coated knee implant were included in this study. All of the tibial components were fixed with screws. The HSS scores were examined preoperatively and at the final follow-up. Radiological assessment was performed with Knee Society evaluating and scoring system. Kaplan-Meier survival analysis was performed to rule out the survival of the tibial component. The mean HSS scores were 45.8 (range 38-60) and 88.1 (range 61-93), preoperatively and at the final follow-up respectively. Complete radiological assessment was performed for 48 knees. Lucent lines at the tibial component were observed in 4 patients; one of these patients underwent a revision surgery due to the loosening of the tibial component. The 10-year survival rate of a tibial component was 98%. Cementless total knee replacement has satisfactory long term clinical results. Primary fixation of the tibial component with screws provides adequate stability even in elderly patients with good bone quality. Level IV, Therapeutic study. Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

Outcomes of Newer Generation Cementless Total Knee Arthroplasty: Beaded Periapatite-Coated vs Highly Porous Titanium-Coated Implants.

PubMed

Harwin, Steven F; Patel, Nirav K; Chughtai, Morad; Khlopas, Anton; Ramkumar, Prem N; Roche, Martin; Mont, Michael A

2017-07-01

Newer generation cementless total knee arthroplasty (TKA) designs are available and have novel implant coatings. We evaluated and compared beaded periapatite (PA)-coated vs highly porous titanium-coated cementless TKAs. Specifically, we compared: (1) survivorship, (2) Knee Society Scores (KSSs) and range of motion, (3) complications, and (4) radiographic findings. There were 805 TKAs with beaded PA-coated tibial and patellar components (PA group; mean age 67 years; range 41-86 years), and 219 TKAs with highly porous titanium-coated tibial and patella components (mean age 66 years; range 34-88 years). Mean follow-up was 4.4 years (range 2-9 years; median 4 years). Implant survivorship was calculated using Kaplan-Meier curves. Student t-tests and chi-square tests were used as appropriate. Radiographic evaluation was performed using Knee Society Roentgenographic Evaluation and Scoring System. All-cause implant survivorship in beaded PA-coated group was 99.5% (95% CI, 97.9%-99.9%) and 99.5% (95% CI, 92.7%-99.9%) in highly porous titanium-coated group. There were no significant differences in the KSS for pain and function. Improvement in flexion and extension was similar in the 2 groups. Overall, complication rate (2.2% vs 2.3%; P = .274) and number of revisions (6 [0.8%] vs 2 [0.2%]; P = .936) were similar in the 2 groups. Excluding the aseptic and septic failures, there were no progressive radiolucencies or osteolysis on radiographic evaluation. This study has shown good clinical and patient-reported outcomes of cementless TKA for both implants. Future multicenter large scale clinical and cost-effectiveness studies are needed to determine the superiority of one cementless implant type over the other. Copyright © 2017 Elsevier Inc. All rights reserved.

Measuring Acetabular Cup Orientation on Antero-Posterior Radiographs of the Hip after Total Hip Arthroplasty with a Vector Arithmetic Radiological Method. Is It Valid and Verified for Daily Clinical Practice?

PubMed

Craiovan, B; Weber, M; Worlicek, M; Schneider, M; Springorum, H R; Zeman, F; Grifka, J; Renkawitz, T

2016-06-01

The aim of this prospective study is to validate a vector arithmetic method for measuring acetabular cup orientation after total hip arthroplasty (THA) and to verify the clinical practice. We measured cup anteversion and inclination of 123 patients after cementless primary THA twice by two examiners on AP pelvic radiographs with a vector arithmetic method and compared with a 3D-CT based reconstruction model within the same radiographic coronal plane. The mean difference between the radiographic and the 3D-CT measurements was - 1.4° ± 3.9° for inclination and 0.8°± 7.9° for anteversion with excellent correlation for inclination (r = 0.81, p < 0.001) and moderate correlation for anteversion (r = 0.65, p < 0.001). The intraclass correlation coefficient for measurements on radiographs ranged from 0.98 (95 %-CI: 0.98; 0.99) for the first observer to 0.94 (95 %-CI: 0.92; 0.96) for the second observer. The interrater reliability was 0.96 (95 %-CI: 0.93; 0.98) for inclination and 0.93 (95 %-CI: 0.85; 0.96) for anteversion. The largest errors in measurements were associated with an extraordinary pelvic tilt. In order to get a valuable measurement for measuring cup position after THA on pelvic radiographs by this vector arithmetic method, there is a need for a correct postoperative ap view, with special regards to the pelvic tilt for the future. • Measuring acetabular cup orientation on anteroposterior radiographs of the hip after THA is a helpful procedure in everyday clinical practice as a first-line imaging modality• CT remains the golden standard to accurately determine acetabular cup position.• Future measuring on radiographs for cup orientation after THA should account for integration of the pelvic tilt in order to maximize the measurement accuracy. Citation Format: • Craiovan B, Weber M, Worlicek M et al. Measuring Acetabular Cup Orientation on Antero-Posterior Radiographs of the Hip after Total Hip Arthroplasty with a Vector Arithmetic Radiological Method. Is It Valid and Verified for Daily Clinical Practice?. Fortschr Röntgenstr 2016; 188: 574 - 581. © Georg Thieme Verlag KG Stuttgart · New York.

Well-fixed acetabular component retention or replacement: the whys and the wherefores.

PubMed

Blaha, J David

2002-06-01

Occasionally the adult reconstructive surgeon is faced with a well-fixed acetabular component that is associated with an arthroplasty problem that ordinarily would require removal and replacement of the cup. Removal of a well-fixed cup is associated with considerable morbidity in bone loss, particularly in the medial wall of the acetabulum. In such a situation, retention of the cup with exchange only of the polyethylene liner may be possible. As preparation for a prospective study, I informally reviewed my experience of cup retention or replacement in revision total hip arthroplasty. An algorithm for retaining or revising a well-fixed acetabular component is presented here. Copyright 2002, Elsevier Science (USA).

Early Migration Predicts Aseptic Loosening of Cementless Femoral Stems: A Long-term Study.

PubMed

Streit, Marcus R; Haeussler, Daniel; Bruckner, Thomas; Proctor, Tanja; Innmann, Moritz M; Merle, Christian; Gotterbarm, Tobias; Weiss, Stefan

2016-07-01

Excessive early migration of cemented stems and cups after THA has been associated with poor long-term survival and allows predictable evaluation of implant performance. However, there are few data regarding the relationship between early migration and aseptic loosening of cementless femoral components, and whether early migration might predict late failure has not been evaluated, to our knowledge. Einzel-Bild-Röntgen-Analyse-femoral component analysis (EBRA-FCA) is a validated technique to accurately measure axial femoral stem migration without the need for tantalum markers, can be performed retrospectively, and may be a suitable tool to identify poor performing implants before their widespread use. We asked: (1) Is axial migration within the first 24 months as assessed by EBRA-FCA greater among cementless stems that develop aseptic loosening than those that remain well fixed through the second decade; (2) what is the diagnostic performance of implant migration at 24 months postoperatively to predict later aseptic loosening of these components; and (3) how does long-term stem survivorship compare between groups with high and low early migration? We evaluated early axial stem migration in 158 cementless THAs using EBRA-FCA. The EBRA-FCA measurements were performed during the first week postoperatively (baseline measurement) and at regular followups of 3, 6, and 12 months postoperatively and annually thereafter. The mean duration of followup was 21 years (range, 18-24 years). The stems studied represented 45% (158 of 354) of the cementless THAs performed during that time, and cementless THAs represented 34% (354 of 1038) of the THA practice during that period. No patient enrolled in this study was lost to followup. Multivariate survivorship analysis using Cox's regression model was performed with an endpoint of aseptic loosening of the femoral component. Loosening was defined according to the criteria described by Engh et al. and assessed by two independent observers. Patients with a diagnosis of prosthetic joint infection were excluded. Receiver operating characteristic (ROC) curve analysis was used to evaluate diagnostic performance of axial stem migration 1, 2, 3, and 4 years postoperatively as a predictor of aseptic loosening. Survivorship of hips with high (≥ 2.7 mm) and low (< 2.7 mm) migration was compared using a competing-events analysis. Femoral components that had aseptic loosening develop showed greater mean distal migration at 24 months postoperatively than did components that remained well fixed throughout the surveillance period (4.2 mm ± 3.1 mm vs 0.8 mm ± 0.9 mm; mean difference, 3.4 mm, 95% CI, 2.5-4.4; p ≤ 0.001). Distal migration at 24 months postoperatively was a strong risk factor for aseptic loosening (hazard ratio, 1.98; 95% CI, 1.51-2.57; p < 0.001). The associated overall diagnostic performance of 2-year distal migration for predicting aseptic loosening was good (area under the ROC curve, 0.86; 95% CI, 0.72-1.00; p < 0.001). Sensitivity of early migration measurement was high for the prediction of aseptic loosening during the first decade after surgery but decreased markedly thereafter. Stems with large amounts of early migration (≥ 2.7 mm) had lower 18-year survivorship than did stems with little early migration (29% [95% CI, 0%-62%] versus 95% [95% CI, 90%-100%] p < 0.001). Early migration, as measured by EBRA-FCA at 2 years postoperatively, has good diagnostic capabilities for detection of uncemented femoral components at risk for aseptic loosening during the first and early second decades after surgery. However, there was no relationship between early migration patterns and aseptic loosening during the late second and third decades. EBRA-FCA can be used as a research tool to evaluate new cementless stems or in clinical practice to evaluate migration patterns in patients with painful femoral components. Level III, diagnostic study.

21 CFR 888.3320 - Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis. 888.3320 Section 888.3320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic...

21 CFR 888.3320 - Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis. 888.3320 Section 888.3320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic...

21 CFR 888.3320 - Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis. 888.3320 Section 888.3320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic...

The Transverse Acetabular Ligament as an Intraoperative Guide to Cup Abduction.

PubMed

Hiddema, Willem B; van der Merwe, Johan F; van der Merwe, Werner

2016-07-01

The success of a total hip arthroplasty relies on optimal acetabular cup placement to ensure mating of the femoral head and acetabular cup throughout all positions of the hip joint. Poor cup placement is associated with dislocation, impingement, microseparation, component loosening, and accelerated wear due to rim loading. This study examined a novel method of using the transverse acetabular ligament (TAL) to guide cup inclination during primary total hip arthroplasty. A descriptive study using 16 hips from 9 cadavers. A computer navigation system measured inclination and version of the acetabular component in 3 positions with the lower edge of cup: (1) flush with, (2) 5 mm proximal to, and (3) 5 mm distal to free border of the TAL. The median inclination angles were 44° in position (1), 30° in position (2), and 64° in position (3). The median anteversion angle for all positions was 19°. Cup inclination was acceptable when the lower edge of the cup was flush or within 5 mm proximal to the TAL. Copyright © 2016 Elsevier Inc. All rights reserved.

Long term survival of an hydroxyapatite-coated threaded cup in the presence of a high polythene wear rate.

PubMed

Datir, Sandeep P; Angus, Peter D

2010-01-01

We describe the long term clinical results and polythene wear rate measurement of 144 uncemented total hip arthroplasties in 118 patients (Male: Female-65: 53, Mean age: 52.8 years (range 21-78 years) performed between 1988 and 2000 using the Furlong HAC coated threaded acetabular cup. The mean follow-up for the group was 10.2 years (range: 5-17.5, median: 9.7). One femoral stem and two acetabular shells were revised due to aseptic loosening. The mean polythene wear rate was 0.24 mm/year. Ten-year survival for the acetabular and femoral components with radiological evidence of aseptic loosening as an end point was 99.15 (CI: 98.3-99.9) and 99.28 (CI: 98.5-99.9). There was no evidence of osteolysis around the femoral or acetabular components in spite of a relatively high polythene wear rate (0.24 mm/year). Our study demonstrates excellent survival of threaded HAC coated acetabular sockets at 10 years in spite of a relatively high polythene wear rate.

Periprosthetic Occult Fractures of the Acetabulum Occur Frequently During Primary THA.

PubMed

Hasegawa, Kazuhiro; Kabata, Tamon; Kajino, Yoshitomo; Inoue, Daisuke; Tsuchiya, Hiroyuki

2017-02-01

Periprosthetic fractures of the acetabulum occurring during primary THA are rare. Periprosthetic occult fractures are defined as those not identified by the surgeon during the procedure which might be missed on a routine postoperative radiograph. However, it is unclear how frequently these fractures occur and whether their presence affects functional recovery. In this study, using routine CT scans that were obtained as part of another primary hip arthroplasty study protocol, we retrospectively assessed (1) the prevalence of occult fractures of the acetabulum occurring during primary THA, (2) the location of occult fractures of the acetabulum during THA, and (3) risk factors contributing to such occult fractures. Between 2004 and 2013, our institute performed 585 primary THAs (cementless or hybrid) in 494 patients with DICOM pre- and postoperative CT; during the period in question, all patients undergoing THA underwent CT before and after surgery. Preoperative CT images were taken as part of a CT-based three-dimensional templating software and navigation system. Postoperative CT images were taken an average of 1 week after surgery as part of a different protocol to evaluate cup position, restoration of leg length and offset, volume of postoperative hematoma to assess anticoagulation effects after THA, and fractures that were not found on routine postoperative radiographs (which we defined as occult fractures). Patients with a history of prior pelvic osteotomy, trauma, and infection were excluded (88 patients/99 hips); 406 patients (102 males and 304 females; 486 hips) form the basis of this report. The mean age of the patients was 60 ± 11 years, with a mean BMI of 23 ± 4 kg/m 2 . The mean followup of the patients with periprosthetic fracture of the acetabulum was 58 ± 28 months (range, 12-131 months). Potential risk factors for occult acetabular fracture including age, sex, BMI, preoperative diagnosis, additional dome screw fixation, composition and size of each cup, and acetabular design were examined in multivariate analysis. Acetabular component designs were categorized as true hemispheric, peripheral self-locking, and elliptical; during the period in question the indications for each cup design were based on the brand of stem used. Comparison between preoperative and postoperative CT images was done to detect the fractures. Patients with fractures identified during surgery were treated with additional dome screw fixation and a 3-week period of nonweightbearing. Patients with occult fractures in this series did not receive additional treatment as we had confirmed secure fixation of the cup during surgery. Occult fractures occurred in 41 hips (8.4%); periprosthetic fractures of the acetabulum were seen during surgery in an additional two hips (0.4%). The superolateral wall was the most frequent location for occult fractures of the acetabulum. After controlling for relevant confounding variables, only the use of peripheral self-locking cups was associated with an increased risk of occult fracture (odds ratio [OR], 2.6 compared with hemispheric cups; 95% CI, 1.2-5.6; p < 0.05). All patients with occult fractures showed bone ingrowth fixation at the final followup, without any additional surgical intervention. Periprosthetic occult fractures of the acetabulum may occur relatively frequently during press-fit impaction. We observed a higher rate of fractures associated with the use of peripheral self-locking components. Occult acetabular fractures not detected on routine postoperative plain films may be ignored if secure fixation of the cup has been confirmed during the operation. Level III, therapeutic study.

Revision of cemented hip arthroplasty using a hydroxyapatite-ceramic-coated femoral component.

PubMed

Raman, R; Kamath, R P; Parikh, A; Angus, P D

2005-08-01

We report the clinical and radiological outcome of 86 revisions of cemented hip arthroplasties using JRI-Furlong hydroxyapatite-ceramic-coated acetabular and femoral components. The acetabular component was revised in 62 hips and the femoral component in all hips. The mean follow-up was 12.6 years and no patient was lost to follow-up. The mean age of the patients was 71.2 years. The mean Harris hip and Oxford scores were 82 (59 to 96) and 23.4 (14 to 40), respectively. The mean Charnley modification of the Merle d'Aubigné and Postel score was 5 (3 to 6) for pain, 4.9 (3 to 6) for movement and 4.4 (3 to 6) for mobility. Migration of the acetabular component was seen in two hips and the mean acetabular inclination was 42.6 degrees. The mean linear polyethylene wear was 0.05 mm/year. The mean subsidence of the femoral component was 1.9 mm and stress shielding was seen in 23 (28%) with bony ingrowth in 76 (94%). Heterotopic ossification was seen in 12 hips (15%). There were three re-revisions, two for deep sepsis and one for recurrent dislocation and there were no re-revisions for aseptic loosening. The mean EuroQol EQ-5D description scores and health thermometer scores were 0.69 (0.51 to 0.89) and 79 (54 to 95), respectively. With an end-point of definite or probable loosening, the probability of survival at 12 years was 93.9% and 95.6% for the acetabular and femoral components, respectively. Overall survival at 12 years, with removal or further revision of either component for any reason as the end-point, was 92.3%. Our study supports the continued use of this arthroplasty and documents the durability of hydroxyapatite-ceramic-coated components.

Initial stability of press-fit acetabular components under rotational forces.

PubMed

Fehring, Keith A; Owen, John R; Kurdin, Anton A; Wayne, Jennifer S; Jiranek, William A

2014-05-01

The primary goal of this study was to determine the initial press-fit stability in acetabular components without screw fixation. Mechanical testing was performed with the implantation of press-fit acetabular components in cadaveric specimens. No significant difference was found in load to failure testing between 1 and 2 mm of under-reaming. However, there was significant variability in bending forces required to create 150 μm of micromotion ranging from 49.3 N to 214.4 N. This study shows that cups implanted in a press-fit fashion, which are felt to be clinically stable, have high degrees of variability in resisting load and may be at risk for loosening. There is a need for more objective intra-operative techniques to test cup stability. © 2014.

Intraoperative Proximal Femoral Fracture in Primary Cementless Total Hip Arthroplasty.

PubMed

Ponzio, Danielle Y; Shahi, Alisina; Park, Andrew G; Purtill, James J

2015-08-01

Intraoperative proximal femoral fracture is a complication of primary cementless total hip arthroplasty (THA) at rates of 2.95-27.8%. A retrospective review of 2423 consecutive primary cementless THA cases identified 102 hips (96 patients) with fracture. Multivariate analysis compared fracture incidences between implants, Accolade (Stryker Orthopaedics) and Tri-Lock (DePuy Orthopaedics, Inc.), and evaluated potential risk factors using a randomized control group of 1150 cases without fracture. The fracture incidence was 4.4% (102/2423), 3.7% (36/1019) using Accolade and 4.9% using Tri-Lock (66/1404) (P=0.18). Female gender (OR=1.96; 95% CI 1.19-3.23; P=0.008) and smaller stem size (OR=1.64; 95% CI 1.04-2.63; P=0.03) predicted increased odds of fracture. No revisions of the femoral component were required in the fracture cohort. Copyright © 2015 Elsevier Inc. All rights reserved.

Bone scans after total knee arthroplasty in asymptomatic patients. Cemented versus cementless

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hofmann, A.A.; Wyatt, R.W.; Daniels, A.U.

1990-02-01

The natural history of bone scans after total knee arthroplasty (TKA) was studied in 26 patients with 28 cemented TKAs and 29 patients with 31 cementless TKAs. The bone scans were examined at specified postoperative intervals. Radionuclide activity of the femoral, tibial, and patellar regions was measured. Six patients who developed pain postoperatively were excluded. Bone scans immediately postoperative and at three months demonstrated increased uptake, which gradually decreased to baseline levels at ten to 12 months. Radioisotope uptake was comparable in the cemented and cementless groups, but was highly variable in individual patients and in each of the follow-upmore » periods. A single postoperative bone scan cannot differentiate component loosening from early bone remodeling. Sequential bone scans, as a supplement to the clinical examination and conventional radiography, may prove useful in the diagnosis of TKA failure.« less

Cement-in-cement acetabular revision with a constrained tripolar component.

PubMed

Leonidou, Andreas; Pagkalos, Joseph; Luscombe, Jonathan

2012-02-17

Dislocation of a total hip replacement (THR) is common following total hip arthroplasty (THA). When nonoperative management fails to maintain reduction, revision surgery is considered. The use of constrained acetabular liners has been extensively described. Complete removal of the old cement mantle during revision THA can be challenging and is associated with significant complications. Cement-in-cement revision is an established technique. However, the available clinical and experimental studies focus on femoral stem revision. The purpose of this study was to present a case of cement-in-cement acetabular revision with a constrained component for recurrent dislocations and to investigate the current best evidence for this technique. This article describes the case of a 74-year-old woman who underwent revision of a Charnley THR for recurrent low-energy dislocations. A tripolar constrained acetabular component was cemented over the primary cement mantle following removal of the original liner by reaming, roughening the surface, and thoroughly irrigating and drying the primary cement. Clinical and radiological results were good, with the Oxford Hip Score improving from 11 preoperatively to 24 at 6 months postoperatively. The good short-term results of this case and the current clinical and biomechanical data encourage the use of the cement-in-cement technique for acetabular revision. Careful irrigation, drying, and roughening of the primary surface are necessary. Copyright 2012, SLACK Incorporated.

Pelvic position and movement during hip replacement.

PubMed

Grammatopoulos, G; Pandit, H G; da Assunção, R; Taylor, A; McLardy-Smith, P; De Smet, K A; Murray, D W; Gill, H S

2014-07-01

The orientation of the acetabular component is influenced not only by the orientation at which the surgeon implants the component, but also the orientation of the pelvis at the time of implantation. Hence, the orientation of the pelvis at set-up and its movement during the operation, are important. During 67 hip replacements, using a validated photogrammetric technique, we measured how three surgeons orientated the patient's pelvis, how much the pelvis moved during surgery, and what effect these had on the final orientation of the acetabular component. Pelvic orientation at set-up, varied widely (mean (± 2, standard deviation (sd))): tilt 8° (2sd ± 32), obliquity -4° (2sd ± 12), rotation -8° (2sd ± 14). Significant differences in pelvic positioning were detected between surgeons (p < 0.001). The mean angular movement of the pelvis between set-up and component implantation was 9° (sd 6). Factors influencing pelvic movement included surgeon, approach (posterior > lateral), procedure (hip resurfacing > total hip replacement) and type of support (p < 0.001). Although, on average, surgeons achieved their desired acetabular component orientation, there was considerable variability (2sd ± 16) in component orientation. We conclude that inconsistency in positioning the patient at set-up and movement of the pelvis during the operation account for much of the variation in acetabular component orientation. Improved methods of positioning and holding the pelvis are required. ©2014 The British Editorial Society of Bone & Joint Surgery.

Towards the optimal design of an uncemented acetabular component using genetic algorithms

NASA Astrophysics Data System (ADS)

Ghosh, Rajesh; Pratihar, Dilip Kumar; Gupta, Sanjay

2015-12-01

Aseptic loosening of the acetabular component (hemispherical socket of the pelvic bone) has been mainly attributed to bone resorption and excessive generation of wear particle debris. The aim of this study was to determine optimal design parameters for the acetabular component that would minimize bone resorption and volumetric wear. Three-dimensional finite element models of intact and implanted pelvises were developed using data from computed tomography scans. A multi-objective optimization problem was formulated and solved using a genetic algorithm. A combination of suitable implant material and corresponding set of optimal thicknesses of the component was obtained from the Pareto-optimal front of solutions. The ultra-high-molecular-weight polyethylene (UHMWPE) component generated considerably greater volumetric wear but lower bone density loss compared to carbon-fibre reinforced polyetheretherketone (CFR-PEEK) and ceramic. CFR-PEEK was located in the range between ceramic and UHMWPE. Although ceramic appeared to be a viable alternative to cobalt-chromium-molybdenum alloy, CFR-PEEK seems to be the most promising alternative material.

Cementless Tapered Wedge Femoral Stems Decrease Subsidence in Obese Patients Compared to Traditional Fit-and-Fill Stems.

PubMed

Grant, Tanner W; Lovro, Luke R; Licini, David J; Warth, Lucian C; Ziemba-Davis, Mary; Meneghini, Robert M

2017-03-01

Femoral component stability and resistance to subsidence is critical for osseointegration and clinical success in cementless total hip arthroplasty. The purpose of this study was to radiographically evaluate the anatomic fit and subsidence of 2 different proximally tapered, porous-coated modern cementless femoral component designs. A retrospective cohort study of 126 consecutive cementless total hip arthroplasties was performed. Traditional fit-and-fill stems were implanted in the first 61 hips with the remaining 65 receiving morphometric tapered wedge stems. Preoperative bone morphology was radiographically assessed by the canal flare index. Canal fill in the coronal plane, subsidence, and the sagittal alignment of stems was measured digitally on immediate and 1-month postoperative radiographs. Demographics and canal flare indices were similar between groups. The percentage of femoral canal fill was greater in the tapered wedge compared to the fit-and-fill stem (P = .001). There was significantly less subsidence in the tapered wedge design (0.3 mm) compared to the fit-and-fill design (1.1 mm) (P = .001). Subsidence significantly increased as body mass index (BMI) increased in the fit-and-fill stems, a finding not observed in the tapered wedge design (P = .013). An anatomically designed morphometric tapered wedge femoral stem demonstrated greater axial stability and decreased subsidence with increasing BMI than a traditional fit-and-fill stem. The resistance to subsidence, irrespective of BMI, is likely due to the inherent axial stability of a tapered wedge design and may be the optimal stem design for obese patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Reconstruction of failed acetabular component in the presence of severe acetabular bone loss: a systematic review.

PubMed

Volpin, A; Konan, S; Biz, C; Tansey, R J; Haddad, F S

2018-04-13

Acetabular revision especially in the presence of severe bone loss is challenging. There is a paucity of literature critiquing contemporary techniques of revision acetabular reconstruction and their outcomes. The purpose of this study was to systematically review the literature and to report clinical outcomes and survival of contemporary acetabular revision arthroplasty techniques (tantalum metal shells, uncemented revision jumbo shells, reinforced cages and rings, oblong shells and custom-made triflange constructs). Full-text papers and those with an abstract in English published from January 2001 to January 2016 were identified through international databases. A total of 50 papers of level IV scientific evidence, comprising 2811 hips in total, fulfilled the inclusion criteria and were included. Overall, patients had improved outcomes irrespective of the technique of reconstruction as documented by postoperative hip scores. Our pooled analysis suggests that oblong cups components had a lower failure rate compared with other different materials considered in this review. Custom-made triflange cups had one of highest failure rates. However, this may reflect the complexity of revisions and severity of bone loss. The most common postoperative complication reported in all groups was dislocation. This review confirms successful acetabular reconstructions using diverse techniques depending on the type of bone loss and highlights key features and outcomes of different techniques. In particular, oblong cups and tantalum shells have successful survivorship.

Influence of cup-center-edge angle on micro-motion at the interface between the cup and host bone in cementless total hip arthroplasty: three-dimensional finite element analysis.

PubMed

Kaku, Nobuhiro; Tabata, Tomonori; Tsumura, Hiroshi

2015-12-01

We verified the index cup position required for bulk bone grafting instead of morcellized grafting immediately after cementless total hip arthroplasty. Three-dimensional finite element analysis was used to evaluate changes in the volume of the slippage of the cup-host bone interface as micro-motion of the cup at the acetabular bone defect site depending on the cup-center-edge (CE) angle. The conditions of bulk bone grafts were similar to those of cortical bone. Slippage increased with decreasing cup-CE angle. A bulk bone graft tightly fixed to the host bone prevented considerably larger slippage between the cup and host bone. A smaller cup-CE angle increased the impact of the bulk bone graft on slippage. When the cup-CE angle was 0° or -10°, the criterion for slippage in favorable initial fixation in all conditions was <40 μm. Even if transplanted bulk bone is used, unless good fixation is obtained between the host bone, and the cup and bone graft, it is impossible to obtain reliable fixation of the cup with a cup-CE angle <-10° and slippage exceeding 40 μm. Bulk bone grafting tightly fixed to the host bone improves initial the cup-host bone fixation, especially when the cup-CE angle is small, such as <-10°. In clinical practice, negative factors are implicated in the initial fixation of various cups, and sufficient fixation between the host bone and cup or bulk bone graft using a screw is effective when the cup-CE angle is extremely small.

A New Automated Way to Measure Polyethylene Wear in THA Using a High Resolution CT Scanner: Method and Analysis

PubMed Central

Maguire Jr., Gerald Q.; Noz, Marilyn E.; Olivecrona, Henrik; Zeleznik, Michael P.

2014-01-01

As the most advantageous total hip arthroplasty (THA) operation is the first, timely replacement of only the liner is socially and economically important because the utilization of THA is increasing as younger and more active patients are receiving implants and they are living longer. Automatic algorithms were developed to infer liner wear by estimating the separation between the acetabular cup and femoral component head given a computed tomography (CT) volume. Two series of CT volumes of a hip phantom were acquired with the femoral component head placed at 14 different positions relative to the acetabular cup. The mean and standard deviation (SD) of the diameter of the acetabular cup and femoral component head, in addition to the range of error in the expected wear values and the repeatability of all the measurements, were calculated. The algorithms resulted in a mean (±SD) for the diameter of the acetabular cup of 54.21 (±0.011) mm and for the femoral component head of 22.09 (±0.02) mm. The wear error was ±0.1 mm and the repeatability was 0.077 mm. This approach is applicable clinically as it utilizes readily available computed tomography imaging systems and requires only five minutes of human interaction. PMID:24587727

Acetabular revisions using porous tantalum components: A retrospective study with 5-10 years follow-up

PubMed Central

Evola, Francesco Roberto; Costarella, Luciano; Evola, Giuseppe; Barchitta, Martina; Agodi, Antonella; Sessa, Giuseppe

2017-01-01

AIM To evaluate the clinical and X-ray results of acetabular components and tantalum augments in prosthetic hip revisions. METHODS Fifty-eight hip prostheses with primary failure of the acetabular component were reviewed with tantalum implants. The clinical records and X-rays of these cases were retrospectively reviewed. Bone defect evaluations were based on preoperative CT scans and classified according to Paprosky criteria of Radiolucent lines and periprosthetic gaps; implant mobilization and osteolysis were evaluated by X-ray. An ad hoc database was created and statistical analyses were performed with SPSS software (IBM SPSS Statistics for Windows, version 23.0). Statistical analyses were carried out using the Student’s t test for independent and paired samples. A P value of < 0.05 was considered statistically significant and cumulative survival was calculated by the Kaplan-Meier method. RESULTS The mean follow-up was 87.6 ± 25.6 mo (range 3-120 mo). 25 cases (43.1%) were classified as minor defects, and 33 cases (56.9%) as major defects. The preoperative HHS rating improved significantly from a mean of 40.7 ± 6.1 (range: 29-53) before revision, to a mean of 85.8 ± 6.1 (range: 70-94) at the end of the follow-up (Student’s t test for paired samples: P < 0.001). Considering HHS only at the end of follow-up, no statistically significant difference was observed between patients with a major or minor defect (Student’s t test for independent samples: P > 0.05). Radiolucent lines were found in 4 implants (6.9%). Postoperative acetabular gaps were observed in 5 hips (8.6%). No signs of implant mobilization or areas of periprosthetic osteolysis were found in the x-rays at the final follow-up. Only 3 implants failed: 1 case of infection and 2 cases of instability. Defined as the end-point, cumulative survival at 10 years was 95% (for all reasons) and 100% for aseptic loosening of the acetabular component. CONCLUSION The medium-term use of prosthetic tantalum components in prosthetic hip revisions is safe and effective in a wide variety of acetabular bone defects. PMID:28808626

Acetabular revisions using porous tantalum components: A retrospective study with 5-10 years follow-up.

PubMed

Evola, Francesco Roberto; Costarella, Luciano; Evola, Giuseppe; Barchitta, Martina; Agodi, Antonella; Sessa, Giuseppe

2017-07-18

To evaluate the clinical and X-ray results of acetabular components and tantalum augments in prosthetic hip revisions. Fifty-eight hip prostheses with primary failure of the acetabular component were reviewed with tantalum implants. The clinical records and X-rays of these cases were retrospectively reviewed. Bone defect evaluations were based on preoperative CT scans and classified according to Paprosky criteria of Radiolucent lines and periprosthetic gaps; implant mobilization and osteolysis were evaluated by X-ray. An ad hoc database was created and statistical analyses were performed with SPSS software (IBM SPSS Statistics for Windows, version 23.0). Statistical analyses were carried out using the Student's t test for independent and paired samples. A P value of < 0.05 was considered statistically significant and cumulative survival was calculated by the Kaplan-Meier method. The mean follow-up was 87.6 ± 25.6 mo (range 3-120 mo). 25 cases (43.1%) were classified as minor defects, and 33 cases (56.9%) as major defects. The preoperative HHS rating improved significantly from a mean of 40.7 ± 6.1 (range: 29-53) before revision, to a mean of 85.8 ± 6.1 (range: 70-94) at the end of the follow-up (Student's t test for paired samples: P < 0.001). Considering HHS only at the end of follow-up, no statistically significant difference was observed between patients with a major or minor defect (Student's t test for independent samples: P > 0.05). Radiolucent lines were found in 4 implants (6.9%). Postoperative acetabular gaps were observed in 5 hips (8.6%). No signs of implant mobilization or areas of periprosthetic osteolysis were found in the x-rays at the final follow-up. Only 3 implants failed: 1 case of infection and 2 cases of instability. Defined as the end-point, cumulative survival at 10 years was 95% (for all reasons) and 100% for aseptic loosening of the acetabular component. The medium-term use of prosthetic tantalum components in prosthetic hip revisions is safe and effective in a wide variety of acetabular bone defects.

The relationship between operative and radiographic acetabular component orientation: which factors influence resultant cup orientation?

PubMed

Grammatopoulos, G; Pandit, H G; da Assunção, R; McLardy-Smith, P; De Smet, K A; Gill, H S; Murray, D W

2014-10-01

There is great variability in acetabular component orientation following hip replacement. The aims of this study were to compare the component orientation at impaction with the orientation measured on post-operative radiographs and identify factors that influence the difference between the two. A total of 67 hip replacements (52 total hip replacements and 15 hip resurfacings) were prospectively studied. Intra-operatively, the orientation of the acetabular component after impaction relative to the operating table was measured using a validated stereo-photogrammetry protocol. Post-operatively, the radiographic orientation was measured; the mean inclination/anteversion was 43° (sd 6°)/ 19° (sd 7°). A simulated radiographic orientation was calculated based on how the orientation would have appeared had an on-table radiograph been taken intra-operatively. The mean difference between radiographic and intra-operative inclination/anteversion was 5° (sd 5°)/ -8° (sd 8°). The mean difference between simulated radiographic and intra-operative inclination/anteversion, which quantifies the effect of the different way acetabular orientation is measured, was 3°/-6° (sd 2°). The mean difference between radiographic and simulated radiographic orientation inclination/anteversion, which is a manifestation of the change in pelvic position between component impaction and radiograph, was 1°/-2° (sd 7°). This study demonstrated that in order to achieve a specific radiographic orientation target, surgeons should implant the acetabular component 5° less inclined and 8° more anteverted than their target. Great variability (2 sd about ± 15°) in the post-operative radiographic cup orientation was seen. The two equally contributing causes for this are variability in the orientation at which the cup is implanted, and the change in pelvic position between impaction and post-operative radiograph. ©2014 The British Editorial Society of Bone & Joint Surgery.

Clinical results of Hi-tech Knee II total knee arthroplasty in patients with rheumatoid athritis: 5- to 12-year follow-up.

PubMed

Yamanaka, Hajime; Goto, Ken-ichiro; Suzuki, Munetaka

2012-02-22

Total knee arthroplasty (TKA) is a common form of treatment to relieve pain and improve function in cases of rheumatoid arthritis (RA). Good clinical outcomes have been reported with a variety of TKA prostheses. The cementless Hi-Tech Knee II cruciate-retaining (CR)-type prosthesis, which has 6 fins at the anterior of the femoral component, posterior cruciate ligament (PCL) retention, flat-on-flat surface component geometry, all-polyethylene patella, strong initial fixation by the center screw of the tibial base plate, 10 layers of titanium alloy fiber mesh, and direct compression molded ultra high molecular weight polyethylene (UHMWPE), is appropriate for TKA in the Japanese knee.The present study was performed to evaluate the clinical results of primary TKA in RA using the cementless Hi-Tech Knee II CR-type prosthesis. We performed 32 consecutive primary TKAs using cementless Hi-Tech Knee II CR-type prosthesis in 31 RA patients. The average follow-up period was 8 years 3 months. Clinical evaluations were performed according to the American Knee Society (KS) system, knee score, function score, radiographic evaluation, and complications. The mean postoperative maximum flexion angle was 115.6°, and the KS knee score and function score improved to 88 and 70 after surgery, respectively. Complications, such as infection, occurred in 1 patient and revision surgery was performed. There were no cases of loosening in this cohort, and prosthesis survival rate was 96.9% at 12 years postoperatively. These results suggest that TKA using the cementless Hi-Tech Knee II CR-type prosthesis is a very effective form of treatment in RA patients at 5 to 12 years postoperatively. Further long-term follow-up studies are required to determine the ultimate utility of this type of prosthesis.

Does oversizing an uncemented cup increase post-operative pain in primary total hip arthroplasty?

PubMed

Barrow, Jonathan A; Divecha, Hiren M; Panchani, Sunil; Boden, Richard; Porter, Martyn L; Board, Tim N

2018-05-31

It has been suggested that one of the factors related to persistent post-operative pain following total hip arthroplasty (THA) is to over sizing of the acetabular component. In order to investigate this potential issue, we retrospectively analysed a series of consecutive uncemented THA. We assessed the incidence of persistent post-operative pain and the size difference between the implanted acetabular component and the native femoral head. A total of 265 consecutive THAs were retrospectively identified. Standardised pre-operative radiographs were analysed using validated techniques to determine the native femoral head diameter. Post-operative standardised radiographs were reviewed and the acetabular orientation determined. Patients were sent postal questionnaires regarding their outcome and level of pain. Questionnaires were returned by 169 patients (189 hips, 71% response rate). A total of 17 were excluded due to inadequate radiographs., leaving 172 THA in the study group. The mean native femoral head (NFH) size was 47 mm. The most common implanted acetabular component size was 52 mm. The mean difference in cup to NFH diameter (delta) was 5.7 mm (range - 6.1 to 15.4 mm; 95% CI 5.3-6.2 mm). A delta of > 6 mm was found to be significant for predicting persistent post-operative pain (RR = 1.81; 95% CI 1.1-3.1; P = 0.027). Our study confirms that a delta of > 6 mm is associated with an increased risk of persistent post-operative pain following THA. We recommend pre-operative templating in all uncemented THA to ensure the planned acetabular component is no more than 6 mm larger than the NFH diameter.

Comparison of Outcomes of Total Hip Arthroplasty between Patients with Ankylosing Spondylitis and Avascular Necrosis of the Femoral Head.

PubMed

Lee, Sun-Ho; Lee, Gun-Woo; Seol, Young-Jun; Park, Kyung-Soon; Yoon, Taek-Rim

2017-09-01

The objective of this study was to compare clinical and radiological outcomes of total hip arthroplasty (THA) between ankylosing spondylitis (AS) of the hip joint and avascular necrosis (AVN) of the femoral head. Thirty patients (30 hips) underwent cementless THA for AS between 2003 and 2012. They were compared to 30 patients (30 hips) who underwent the same procedure for AVN of the femoral head. Each group was matched for age and gender, and both groups had similar preoperative demographic characteristics. All cases were followed for minimum 4 postoperative years. Clinical evaluation was based on operation time, intraoperative blood loss, quantity of postoperative drainage, Harris Hip Score (HHS), and range of motion (ROM). Radiological results were evaluated by acetabular cup anteversion and inclination, femoral stem orientation, pre- and postoperative leg length discrepancy, and postoperative complications. The operation time was significantly longer in the AS group (120.2 ± 26.2 min) than in the AVN group (79.5 ± 11.1 min). The volume of postoperative drainage was significantly greater in the AS group (764.5 ± 355.4 mL vs. 510.5 ± 195.6 mL). Preoperative HHS was lower in the AS group (55.6 ± 13.8 vs. 59.2 ± 2.8). Similarly, postoperative HHS was significantly lower in the AS group (92.8 ± 2.7 vs. 97.4 ± 2.6). The arc of ROM was improved from 146.5° ± 13.2° preoperatively to 254.7° ± 17.2° postoperatively in the AS group and from 182.6° ± 15.5° to 260.4° ± 13.7° in the AVN group. Implant position and postoperative leg length discrepancy were not different between the groups. However, three cases of heterotopic ossification was observed in the AS group, whereas only 1 case was found in the AVN group. One deep infection and one aseptic stem loosening were found in the AS group, whereas none was observed in the AVN group. Cementless THA showed satisfactory clinical and radiological results in both groups, despite the longer operation time, larger blood loss volume, and lower HHS score of the AS group. Our findings suggest that cementless THA is an effective and reliable treatment for both AS and AVN.

Preclinical trial of a novel surface architecture for improved primary fixation of cementless orthopaedic implants.

PubMed

Harrison, Noel; Field, John R; Quondamatteo, Fabio; Curtin, William; McHugh, Peter E; Mc Donnell, Pat

2014-09-01

A new surface architecture for cementless orthopaedic implants (OsteoAnchor), which incorporates a multitude of tiny anchor features for enhancing primary fixation, was tested in an ovine hemi-arthroplasty pilot study. Test animals were implanted with a hip stem component incorporating the OsteoAnchor surface architecture produced using additive layer manufacturing and control animals were implanted with stems containing a standard plasma sprayed titanium coating. Intra-operative surgeon feedback indicated that superior primary fixation was achieved for the OsteoAnchor stems and rapid return to normal gait and load bearing was observed post-operation. Following a 16-week recovery time, histological evaluation of the excised femurs revealed in-growth of healthy bone into the porous structure of the OsteoAnchor stems. Bone in-growth was not achieved for the plasma sprayed stems. These results indicate the potential for the OsteoAnchor surface architecture to enhance both the initial stability and long term lifetime of cementless orthopaedic implants. Copyright © 2014 Elsevier Ltd. All rights reserved.

An unusual mode of failure of a tripolar constrained acetabular liner: a case report.

PubMed

Banks, Louisa N; McElwain, John P

2010-04-01

Dislocation after primary total hip arthroplasty (THA) is the most commonly encountered complication and is unpleasant for both the patient and the surgeon. Constrained acetabular components can be used to treat or prevent instability after primary total hip arthroplasty. We present the case of a 42-year-old female with a BMI of 41. At 18 months post-primary THA the patient underwent further revision hip surgery after numerous (more than 20) dislocations. She had a tripolar Trident acetabular cup (Stryker-Howmedica-Osteonics, Rutherford, New Jersey) inserted. Shortly afterwards the unusual mode of failure of the constrained acetabular liner was noted from radiographs in that the inner liner had dissociated from the outer. The reinforcing ring remained intact and in place. We believe that the patient's weight, combined with poor abductor musculature caused excessive demand on the device leading to failure at this interface when the patient flexed forward. Constrained acetabular components are useful implants to treat instability but have been shown to have up to 42% long-term failure rates with problems such as dissociated inserts, dissociated constraining rings and dissociated femoral rings being sited. Sometimes they may be the only option left in difficult cases such as illustrated here, but still unfortunately have the capacity to fail in unusual ways.

Cemented total hip replacement cable debris and acetabular construct durability.

PubMed

Altenburg, Aaron J; Callaghan, John J; Yehyawi, Tameem M; Pedersen, Douglas R; Liu, Steve S; Leinen, Jessica A; Dahl, Kevin A; Goetz, Devon D; Brown, Thomas D; Johnston, Richard C

2009-07-01

Third-body wear can adversely affect the outcome of total hip arthroplasty by causing increased polyethylene wear, osteolysis, and component loosening. We hypothesized that there would be greater generation and migration of metal debris to the bearing surfaces in hips in which cobalt-chromium cables were used to reattach the osteotomized greater trochanter when compared with hips in which stainless steel wires were used. Between June 1981 and December 1983, 196 consecutive total hip arthroplasties were performed with use of an Iowa stem and a titanium-backed cemented acetabular component, with cobalt-chromium cable trochanteric reattachment. After nineteen to twenty years of follow-up, the patients were evaluated with regard to the depth of head penetration into the polyethylene (as a surrogate for wear), osteolysis, loosening, and the need for revision. The results were compared with those for a series of 304 total hip arthroplasties that were performed by the same surgeon from January 1984 to December 1985 with use of the same components and the same surgical technique, but with stainless steel wire trochanteric reattachment. The two groups had a comparable nineteen to twenty-year follow-up. All living patients (fifty-nine hips in the cable group and ninety-two hips in the wire group) had minimum ten-year follow-up radiographs. The polyethylene wear rate was 0.101 mm/yr for the cable group and 0.082 mm/yr for the wire group (p = 0.039). For the living patients, the rate of revision of the acetabular component because of aseptic loosening was 37.3% (twenty-two hips) for the cable group and 20.7% (nineteen hips) for the wire group (p = 0.025). The rate of acetabular osteolysis was 44% (twenty-six hips) for the cable group and 26% (twenty-four hips) for the wire group (p = 0.022). Kaplan-Meier analysis with revision of the acetabular component because of aseptic loosening as the end point demonstrated survival rates of 73.7% +/- 9% and 83% +/- 7% for the cable and wire groups, respectively, at twenty years (p = 0.03). Because cable trochanteric attachment led to significantly greater polyethylene wear, osteolysis, acetabular loosening, and acetabular revision, presumably due to third-body metallic debris generation in this cemented total hip replacement construct, surgeons should be aware of the deleterious effects of third-body debris and avoid the use of potential debris generators in the total hip arthroplasty construct. If cable is used and fretting is recognized, especially with intra-articular migration of metallic material or nonunion of the greater trochanter, consideration should be given to cable removal.

Survival of cementless femoral components after osteonecrosis of the femoral head with different etiologies.

PubMed

Radl, Roman; Egner, Sigrun; Hungerford, Marc; Rehak, Peter; Windhager, Reinhard

2005-06-01

We reviewed 41 patients with 55 cementless total hip arthroplasty operated for advanced osteonecrosis. Patients were divided into 2 groups according to etiology of the osteonecrosis. The first group included 17 cases with osteonecrosis without a systemic disease and the second group 38 cases with osteonecrosis associated with a systemic disease. The follow-up was on average 6.4 years (range, 2-12.8). Eight (15.4%) stem revisions had to be performed; all of them were in the patients with a systemic disease. Ten-year survival rates with femoral revision as the endpoint were in the first group 100% and in the systemic disease group 68% (P = .03). The data of this retrospective study indicate a correlation between the survival of the femoral component and the etiology of the osteonecrosis.

What Safe Zone? The Vast Majority of Dislocated THAs Are Within the Lewinnek Safe Zone for Acetabular Component Position.

PubMed

Abdel, Matthew P; von Roth, Philipp; Jennings, Matthew T; Hanssen, Arlen D; Pagnano, Mark W

2016-02-01

Numerous factors influence total hip arthroplasty (THA) stability including surgical approach and soft tissue tension, patient compliance, and component position. One long-held tenet regarding component position is that cup inclination and anteversion of 40° ± 10° and 15° ± 10°, respectively, represent a "safe zone" as defined by Lewinnek that minimizes dislocation after primary THA; however, it is clear that components positioned in this zone can and do dislocate. We sought to determine if these classic radiographic targets for cup inclination and anteversion accurately predicted a safe zone limiting dislocation in a contemporary THA practice. From a cohort of 9784 primary THAs performed between 2003 and 2012 at one institution, we retrospectively identified 206 THAs (2%) that subsequently dislocated. Radiographic parameters including inclination, anteversion, center of rotation, and limb length discrepancy were analyzed. Mean followup was 27 months (range, 0-133 months). The majority (58% [120 of 206]) of dislocated THAs had a socket within the Lewinnek safe zone. Mean cup inclination was 44° ± 8° with 84% within the safe zone for inclination. Mean anteversion was 15° ± 9° with 69% within the safe zone for anteversion. Sixty-five percent of dislocated THAs that were performed through a posterior approach had an acetabular component within the combined acetabular safe zones, whereas this was true for only 33% performed through an anterolateral approach. An acetabular component performed through a posterior approach was three times as likely to be within the combined acetabular safe zones (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.1-1.6) than after an anterolateral approach (OR, 0.4; 95% CI, 0.2-0.7; p < 0.0001). In contrast, acetabular components performed through a posterior approach (OR, 1.6; 95% CI, 1.2-1.9) had an increased risk of dislocation compared with those performed through an anterolateral approach (OR, 0.8; 95% CI, 0.7-0.9; p < 0.0001). The historical target values for cup inclination and anteversion may be useful but should not be considered a safe zone given that the majority of these contemporary THAs that dislocated were within those target values. Stability is likely multifactorial; the ideal cup position for some patients may lie outside the Lewinnek safe zone and more advanced analysis is required to identify the right target in that subgroup. Level III, therapeutic study.

Robotic-arm assisted total hip arthroplasty results in smaller acetabular cup size in relation to the femoral head size: a matched-pair controlled study.

PubMed

Suarez-Ahedo, Carlos; Gui, Chengcheng; Martin, Timothy J; Chandrasekaran, Sivashankar; Lodhia, Parth; Domb, Benjamin G

2017-03-31

To compare the acetabular component size relative to the patient's native femoral head size between conventional THA (CTHA) approach and robotic-arm assisted THA (RTHA) to infer which of these techniques preserved more acetabular bone. Patients were included if they had primary osteoarthritis (OA) and underwent total hip replacement between June 2008 and March 2014. Patients were excluded if they had missing or rotated postoperative anteroposterior radiographs. RTHA patients were matched to a control group of CTHA patients, in terms of preoperative native femoral head size, age, gender, body mass index (BMI) and approach. Acetabular cup size relative to femoral head size was used as a surrogate for amount of bone resected. We compared the groups according to 2 measures describing acetabular cup diameter (c) in relation to femoral head diameter (f): (i) c-f, the difference between cup diameter and femoral head diameter and (ii) (c-f)/f, the same difference as a fraction of femoral head diameter. 57 matched pairs were included in each group. There were no significant differences between groups for demographic measures, femoral head diameter, or acetabular cup diameter (p>0.05). However, measures (i) and (ii) did differ significantly between the groups, with lower values in the RTHA group (p<0.02). Using acetabular cup size relative to femoral head size as an approximate surrogate measure of acetabular bone resection may suggest greater preservation of bone stock using RTHA compared to CTHA. Further studies are needed to validate the relationship between acetabular cup size and bone loss in THA.

Hot topics and controversies in arthroplasty: cementless femoral fixation in elderly patients.

PubMed

Dutton, Andrew; Rubash, Harry E

2008-01-01

Cementless femoral fixation has been established as the gold standard for hip arthroplasty in young patients because of its exceptional longevity. Because older Americans are living longer and staying active, cementless femoral fixation for hip arthroplasty should be considered in all patients who have good bone quality. Numerous studies have shown excellent results using cementless fixation for hip arthroplasty in elderly patients. Histologic analysis, radiographic review, and dual-energy x-ray absorptiometry have shown solid osseointegration for biologic fixation and minimal bone loss. Cementless fixation provides superb functional outcomes with results comparable to those achieved using cemented fixation for hip arthroplasty. Additional advantages of cementless femoral fixation include shorter surgical times and substantial savings in health care costs.

Risk factors for accelerated polyethylene wear and osteolysis in ABG I total hip arthroplasty

PubMed Central

Havranek, Vitezslav; Zapletalova, Jana

2009-01-01

We analysed data from 155 revisions of identical cementless hip prostheses to determine the influence of patient-, implant- and surgery-related factors on the polyethylene wear rate and size of periprosthetic osteolysis (OL). This was calculated by logistic regression analysis. Factors associated with an increased/decreased wear rate included position of the cup relative to Kohler’s line, increase in abduction angle of the cup, traumatic and inflammatory arthritis as a primary diagnosis, and patient height. Severe acetabular bone defects were predicted by an increased wear rate (odds ratio, OR = 5.782 for wear rate above 200 mm3/y), and increased height of the patient (OR = 0.905 per each centimetre). Predictors of severe bone defects in the femur were the increased wear rate (OR = 3.479 for wear rate above 200 mm3/y) and placement of the cup outside of the true acetabulum (OR = 3.292). Variables related to surgical technique were the most predictive of polyethylene wear rate. PMID:19214506

Cerclage wires or cables for the management of intraoperative fracture associated with a cementless, tapered femoral prosthesis: results at 2 to 16 years.

PubMed

Berend, Keith R; Lombardi, Adolph V; Mallory, Thomas H; Chonko, Douglas J; Dodds, Kathleen L; Adams, Joanne B

2004-10-01

Initial stability is critical for fixation and survival of cementless total hip arthroplasty. Occasionally, a split of the calcar occurs intraoperatively. A review of 1,320 primary total hip arthroplasties with 2-year follow-up, performed between August 1985 and February 2001 using the Mallory-Head Porous tapered femoral component, revealed 58 hips in 55 patients with an intraoperative calcar fracture managed with single or multiple cerclage wires or cables and immediate full weight bearing. At 7.5 years average follow-up (range, 2-16 years), there were no revisions of the femoral component, radiographic failures, or patients with severe thigh pain, for a stem survival rate of 100%. Average Harris hip score improvement was 33.8 points. Fracture of the proximal femur occurs in approximately 4% of primary THAs using the Mallory-Head Porous femoral component. When managed intraoperatively with cerclage wire or cable, the mid- to long-term results appear unaffected with 100% femoral component survival at up to 16 years.

Application of Rapid Prototyping Pelvic Model for Patients with DDH to Facilitate Arthroplasty Planning: A Pilot Study.

PubMed

Xu, Jie; Li, Deng; Ma, Ruo-fan; Barden, Bertram; Ding, Yue

2015-11-01

Total hip arthroplasty (THA) is challenging in cases of osteoarthritis secondary to developmental dysplasia of the hip (DDH). Acetabular deficiency makes the positioning of the acetabular component difficult. Computer tomography based, patient-individual three dimensional (3-D) rapid prototype technology (RPT)-models were used to plan the placement of acetabular cup so that a surgeon was able to identify pelvic structures, assess the ideal extent of reaming and determine the size of cup after a reconstructive procedure. Intraclass correlation coefficients (ICCs) were used to analyze the agreement between the sizes of chosen components on the basis of preoperative planning and the actual sizes used in the operation. The use of the 3-D RPT-model facilitates the surgical procedures due to better planning and improved orientation. Copyright © 2015 Elsevier Inc. All rights reserved.

Impact of a learning curve on the survivorship of 4802 cementless total hip arthroplasties.

PubMed

Magill, P; Blaney, J; Hill, J C; Bonnin, M P; Beverland, D E

2016-12-01

Our aim was to report survivorship data and lessons learned with the Corail/Pinnacle cementless total hip arthroplasty (THA) system. Between August 2005 and March 2015, a total of 4802 primary cementless Corail/Pinnacle THAs were performed in 4309 patients. In March 2016, we reviewed these hips from a prospectively maintained database. A total of 80 hips (1.67%) have been revised which is equivalent to a cumulative risk of revision of 2.5% at ten years. The rate of revision was not significantly higher in patients aged ≥ 70 years (p = 0.93). The leading indications for revision were instability (n = 22, 0.46%), infection (n = 20, 0.42%), aseptic femoral loosening (n = 15, 0.31%) and femoral fracture (n = 6, 0.12%). There were changes in the surgical technique with respect to the Corail femoral component during the ten-year period involving a change to collared components and a trend towards larger size. These resulted in a decrease in the rate of iatrogenic femoral fracture and a decrease in the rate of aseptic loosening. The rate of revision in this series is comparable with the best performing THAs in registry data. Most revisions were not directly related to the implants. Despite extensive previous experience with cemented femoral components, the senior author noted a learning curve requiring increased focus on primary stability. The number of revisions related to the femoral component is reducing. Any new technology has a learning curve that may be independent of surgical experience. Cite this article: Bone Joint J 2016;98-B:1589-96. ©2016 The British Editorial Society of Bone & Joint Surgery.

Cemented Total Hip Replacement Cable Debris and Acetabular Construct Durability

PubMed Central

Altenburg, Aaron J.; Callaghan, John J.; Yehyawi, Tameem M.; Pedersen, Douglas R.; Liu, Steve S.; Leinen, Jessica A.; Dahl, Kevin A.; Goetz, Devon D.; Brown, Thomas D.; Johnston, Richard C.

2009-01-01

Background: Third-body wear can adversely affect the outcome of total hip arthroplasty by causing increased polyethylene wear, osteolysis, and component loosening. We hypothesized that there would be greater generation and migration of metal debris to the bearing surfaces in hips in which cobalt-chromium cables were used to reattach the osteotomized greater trochanter when compared with hips in which stainless steel wires were used. Methods: Between June 1981 and December 1983, 196 consecutive total hip arthroplasties were performed with use of an Iowa stem and a titanium-backed cemented acetabular component, with cobalt-chromium cable trochanteric reattachment. After nineteen to twenty years of follow-up, the patients were evaluated with regard to the depth of head penetration into the polyethylene (as a surrogate for wear), osteolysis, loosening, and the need for revision. The results were compared with those for a series of 304 total hip arthroplasties that were performed by the same surgeon from January 1984 to December 1985 with use of the same components and the same surgical technique, but with stainless steel wire trochanteric reattachment. The two groups had a comparable nineteen to twenty-year follow-up. All living patients (fifty-nine hips in the cable group and ninety-two hips in the wire group) had minimum ten-year follow-up radiographs. Results: The polyethylene wear rate was 0.101 mm/yr for the cable group and 0.082 mm/yr for the wire group (p = 0.039). For the living patients, the rate of revision of the acetabular component because of aseptic loosening was 37.3% (twenty-two hips) for the cable group and 20.7% (nineteen hips) for the wire group (p = 0.025). The rate of acetabular osteolysis was 44% (twenty-six hips) for the cable group and 26% (twenty-four hips) for the wire group (p = 0.022). Kaplan-Meier analysis with revision of the acetabular component because of aseptic loosening as the end point demonstrated survival rates of 73.7% ± 9% and 83% ± 7% for the cable and wire groups, respectively, at twenty years (p = 0.03). Conclusions: Because cable trochanteric attachment led to significantly greater polyethylene wear, osteolysis, acetabular loosening, and acetabular revision, presumably due to third-body metallic debris generation in this cemented total hip replacement construct, surgeons should be aware of the deleterious effects of third-body debris and avoid the use of potential debris generators in the total hip arthroplasty construct. If cable is used and fretting is recognized, especially with intra-articular migration of metallic material or nonunion of the greater trochanter, consideration should be given to cable removal. Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence. PMID:19571089

Clinical results of Hi-tech Knee II total knee arthroplasty in patients with rheumatoid athritis: 5- to 12-year follow-up

PubMed Central

2012-01-01

Background Total knee arthroplasty (TKA) is a common form of treatment to relieve pain and improve function in cases of rheumatoid arthritis (RA). Good clinical outcomes have been reported with a variety of TKA prostheses. The cementless Hi-Tech Knee II cruciate-retaining (CR)-type prosthesis, which has 6 fins at the anterior of the femoral component, posterior cruciate ligament (PCL) retention, flat-on-flat surface component geometry, all-polyethylene patella, strong initial fixation by the center screw of the tibial base plate, 10 layers of titanium alloy fiber mesh, and direct compression molded ultra high molecular weight polyethylene (UHMWPE), is appropriate for TKA in the Japanese knee. The present study was performed to evaluate the clinical results of primary TKA in RA using the cementless Hi-Tech Knee II CR-type prosthesis. Materials and methods We performed 32 consecutive primary TKAs using cementless Hi-Tech Knee II CR-type prosthesis in 31 RA patients. The average follow-up period was 8 years 3 months. Clinical evaluations were performed according to the American Knee Society (KS) system, knee score, function score, radiographic evaluation, and complications. Results The mean postoperative maximum flexion angle was 115.6°, and the KS knee score and function score improved to 88 and 70 after surgery, respectively. Complications, such as infection, occurred in 1 patient and revision surgery was performed. There were no cases of loosening in this cohort, and prosthesis survival rate was 96.9% at 12 years postoperatively. Conclusion These results suggest that TKA using the cementless Hi-Tech Knee II CR-type prosthesis is a very effective form of treatment in RA patients at 5 to 12 years postoperatively. Further long-term follow-up studies are required to determine the ultimate utility of this type of prosthesis. PMID:22356935

Acetabular revision with impaction bone grafting and a cemented polyethylene acetabular component: comparison of the Kaplan-Meier analysis to the competing risk analysis in 62 revisions with 25 to 30 years follow-up.

PubMed

Te Stroet, M A J; Keurentjes, J C; Rijnen, W H C; Gardeniers, J W M; Verdonschot, N; Slooff, T J J H; Schreurs, B W

2015-10-01

We present the results of 62 consecutive acetabular revisions using impaction bone grafting and a cemented polyethylene acetabular component in 58 patients (13 men and 45 women) after a mean follow-up of 27 years (25 to 30). All patients were prospectively followed. The mean age at revision was 59.2 years (23 to 82). We performed Kaplan-Meier (KM) analysis and also a Competing Risk (CR) analysis because with long-term follow-up, the presence of a competing event (i.e. death) prevents the occurrence of the endpoint of re-revision. A total of 48 patients (52 hips) had died or had been re-revised at final review in March 2011. None of the deaths were related to the surgery. The mean Harris hip score of the ten surviving hips in ten patients was 76 points (45 to 99). The KM survivorship at 25 years for the endpoint 're-revision for any reason' was 58.0% (95% confidence interval (CI) 38 to 73) and for 're-revision for aseptic loosening' 72.1% (95% CI 51 to 85). With the CR analysis we calculated the KM analysis overestimates the failure rate with respectively 74% and 93% for these endpoints. The current study shows that acetabular impaction bone grafting revisions provide good clinical results at over 25 years. ©2015 The British Editorial Society of Bone & Joint Surgery.

Aseptic loosening of cobalt chromium monoblock sockets after hip resurfacing.

PubMed

Amstutz, Harlan C; Le Duff, Michel J

2015-01-01

Acetabular component loosening is a leading cause for revision after metal-on-metal hip resurfacing arthroplasty (MMHRA). We aimed to identify potential risk factors and determine radiographic signs associated with this mode of failure. From a series of 1375 hips treated with MMHRA, 21 (20 patients) underwent revision surgery secondary to aseptic loosening of the acetabular component and 6 patients had a radiographically loose acetabular component. A control group of 27 hips (26 patients) was selected among the patients that did not have a revision, and was matched for age, gender, component size and diagnosis. Mean time to revision in the loosening group was 103.0 months and the mean time of follow-up in the control group was 161.4 months. We found greater activity levels, range of motion scores, and cup abduction angles in the loosening group. The centre-edge (CE) angle of Wiberg was 10° lower in the loosening group compared with the control group. In addition, 11 of the hips from the study group presented a sclerotic halo superior to the cup on the last radiograph vs. none in the control group. There was no difference in the prevalence of postoperative reaming gaps or radiographic signs of neck-cup impingement between the 2 groups. Risk factors for acetabular loosening included hip dysplasia with low CE angle, and a large cup abduction angle. The patient's level of activity influences the appearance of symptoms and the time to revision. We recommend selecting patients with a sufficient CE angle and properly orienting the cup.

Gamma inert sterilization: a solution to polyethylene oxidation?

PubMed

Medel, Francisco J; Kurtz, Steven M; Hozack, William J; Parvizi, Javad; Purtill, James J; Sharkey, Peter F; MacDonald, Daniel; Kraay, Matthew J; Goldberg, Victor; Rimnac, Clare M

2009-04-01

In the 1990s, oxidation was found to occur in ultra-high molecular weight polyethylene total joint replacement components following gamma irradiation and prolonged shelf aging in air. Orthopaedic manufacturers developed barrier packaging to reduce oxidation during and after radiation sterilization. The present study explores the hypothesis that polyethylene components sterilized in a low-oxygen environment undergo similar in vivo oxidative mechanisms as inserts sterilized in air. In addition, the potential influence of the different sterilization processes on the wear performance of the polyethylene components was examined. An analysis of oxidation, wear, and surface damage was performed for forty-eight acetabular liners and 123 tibial inserts. The mean implantation time was 12.3+/-3.7 years for thirty-one acetabular liners that had been gamma sterilized in air and 4.0+/-2.5 years for the seventeen acetabular liners that had been gamma sterilized in inert gas. The mean implantation time was 11.0+/-3.2 years for the twenty-six tibial inserts that had been sterilized in air and 2.8+/-2.2 years for the ninety-seven tibial inserts that had been gamma sterilized in inert gas. Oxidation and hydroperoxide levels were characterized in loaded and unloaded regions of the inserts. Measurable oxidation and oxidation potential were observed in all cohorts. The oxidation and hydroperoxide levels were regional. Surfaces with access to body fluids were more heavily oxidized than protected bearing surfaces were. This variation appeared to be greater in historical (gamma-in-air-sterilized) components. Regarding wear performance, historical and conventional acetabular liners showed similar wear penetration rates, whereas a low incidence of delamination was confirmed for the conventional tibial inserts in the first decade of implantation. The present study explores the impact of industry-wide changes in sterilization practices for polyethylene. We found lower oxidation and oxidation potential in the conventional acetabular liners and tibial inserts that had been gamma sterilized in inert gas as compared with the historical components that had been gamma sterilized in air. However, we also found strong evidence that conventional components undergo mechanisms of in vivo oxidation similar to those observed following gamma irradiation in air. In addition, gamma sterilization in inert gas did not provide polyethylene with a significant improvement in terms of wear resistance as compared with gamma sterilization in air, except for a lower incidence of delamination in the first decade of implantation for tibial inserts.

Experimental pre-clinical assessment of the primary stability of two cementless femoral knee components.

PubMed

Berahmani, Sanaz; Hendriks, Maartje; Wolfson, David; Wright, Abraham; Janssen, Dennis; Verdonschot, Nico

2017-11-01

To achieve long-lasting fixation of cementless implants, an adequate primary stability is required. We aimed to compare primary stability of a new cementless femoral knee component (Attune®) against a conventional implant (LCS®) under different loading conditions. Six pairs of femora were prepared following the normal surgical procedure. Calibrated CT-scans and 3D-optical scans of the bones were obtained to measure bone mineral density (BMD) and cut accuracy, respectively. Micromotions were measured in nine regions of interest at the bone-implant interface using digital image correlation. The reconstructions were subjected to the implant-specific's peak tibiofemoral load of gait and a deep knee bend loading profiles. Afterwards, the implants were pushed-off at a flexion angle of 150°. Micromotions of Attune were significantly lower than LCS under both loading conditions (P ≤ 0.001). Cut accuracy did not affect micromotions, and BMD was only a significant factor affecting the micromotions under simplified gait loading. No significant difference was found in high-flex push-off force, but Attune required a significantly higher load to generate excessive micromotions during push-off. Parallel anterior and posterior bone cuts in the LCS versus the tapered bone cuts of the Attune may explain the difference between the two designs. Additionally, the rims at the borders of the LCS likely reduced the area of contact with the bone for the LCS, which may have affected the initial fixation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Independent predictors of failure up to 7.5 years after 35 386 single-brand cementless total hip replacements: a retrospective cohort study using National Joint Registry data.

PubMed

Jameson, S S; Baker, P N; Mason, J; Rymaszewska, M; Gregg, P J; Deehan, D J; Reed, M R

2013-06-01

The popularity of cementless total hip replacement (THR) has surpassed cemented THR in England and Wales. This retrospective cohort study records survival time to revision following primary cementless THR with the most common combination (accounting for almost a third of all cementless THRs), and explores risk factors independently associated with failure, using data from the National Joint Registry for England and Wales. Patients with osteoarthritis who had a DePuy Corail/Pinnacle THR implanted between the establishment of the registry in 2003 and 31 December 2010 were included within analyses. There were 35 386 procedures. Cox proportional hazard models were used to analyse the extent to which the risk of revision was related to patient, surgeon and implant covariates. The overall rate of revision at five years was 2.4% (99% confidence interval 2.02 to 2.79). In the final adjusted model, we found that the risk of revision was significantly higher in patients receiving metal-on-metal (MoM: hazard ratio (HR) 1.93, p < 0.001) and ceramic-on-ceramic bearings (CoC: HR 1.55, p = 0.003) compared with the best performing bearing (metal-on-polyethylene). The risk of revision was also greater for smaller femoral stems (sizes 8 to 10: HR 1.82, p < 0.001) compared with mid-range sizes. In a secondary analysis of only patients where body mass index (BMI) data were available (n = 17 166), BMI ≥ 30 kg/m(2) significantly increased the risk of revision (HR 1.55, p = 0.002). The influence of the bearing on the risk of revision remained significant (MoM: HR 2.19, p < 0.001; CoC: HR 2.09, p = 0.001). The risk of revision was independent of age, gender, head size and offset, shell, liner and stem type, and surgeon characteristics. We found significant differences in failure between bearing surfaces and femoral stem size after adjustment for a range of covariates in a large cohort of single-brand cementless THRs. In this study of procedures performed since 2003, hard bearings had significantly higher rates of revision, but we found no evidence that head size had an effect. Patient characteristics, such as BMI and American Society of Anesthesiologists grade, also influence the survival of cementless components.

Effect of screw fixation on acetabular component alignment change in total hip arthroplasty.

PubMed

Fujishiro, Takaaki; Hayashi, Shinya; Kanzaki, Noriyuki; Hashimoto, Shingo; Shibanuma, Nao; Kurosaka, Masahiro

2014-06-01

The use of screws can enhance immediate cup fixation, but the influence of screw insertion on cup position has not previously been measured. The purpose of this study was to quantitatively evaluate the effect of intra-operative screw fixation on acetabular component alignment that has been inserted with the use of a navigation system. We used a navigation system to measure cup alignment at the time of press-fit and after screw fixation in 144 hips undergoing total hip arthroplasty. We also compared those findings with factors measured from postoperative radiographs. The mean intra-operative change of cup position was 1.78° for inclination and 1.81° for anteversion. The intra-operative change of anteversion correlated with the number of screws. The intra-operative change of inclination also correlated with medial hip centre. The insertion of screws can induce changes in cup alignment, especially when multiple screws are used or if a more medial hip centre is required for rigid acetabular fixation.

Endoscopic resection of acetabular screw tip to decompress sciatic nerve following total hip arthroplasty.

PubMed

Yoon, Sun-Jung; Park, Myung-Sik; Matsuda, Dean K; Choi, Yun Ho

2018-06-04

Sciatic nerve injuries following total hip arthroplasty are disabling complications. Although degrees of injury are variable from neuropraxia to neurotmesis, mechanical irritation of sciatic nerve might be occurred by protruding hardware. This case shows endoscopic decompression for protruded acetabular screw irritating sciatic nerve, the techniques described herein may permit broader arthroscopic/endoscopic applications for management of complications after reconstructive hip surgery. An 80-year-old man complained of severe pain and paresthesias following acetabular component revision surgery. Physical findings included right buttock pain with radiating pain to lower extremity. Radiographs and computed tomography imaging showed that the sharp end of protruded screw invaded greater sciatic foramen anterior to posterior and distal to proximal direction at sciatic notch level. A protruding tip of the acetabular screw at the sciatic notch was decompressed by use of techniques gained from experience performing endoscopic sciatic nerve decompression. The pre-operative pain and paresthesias resolved post-operatively after recovering from anesthesia. This case report describes the first documented endoscopic resection of the tip of the acetabular screw irritating sciatic nerve after total hip arthroplasty. If endoscopic resection of an offending acetabular screw can be performed in a safe and minimally invasive manner, one can envision a future expansion of the role of hip arthroscopic surgery in several complications management after total hip arthroplasty.

To Cement or Not? Two-Year Results of a Prospective, Randomized Study Comparing Cemented Vs. Cementless Total Knee Arthroplasty (TKA).

PubMed

Fricka, Kevin B; Sritulanondha, Supatra; McAsey, Craig J

2015-09-01

The optimal mode of fixation in total knee arthroplasty (TKA) is a subject of debate. We enrolled 100 TKA patients randomized to cemented or cementless fixation. Knee Society Scores (KSS), Oxford scores and pain visual analog scales (VAS) were collected pre-operatively and post-operatively. Two-year follow-up was obtained for 93 patients. The mean VAS trended higher for the cementless group at 4 months (P=0.06). At 2 years, the KSS functional scores, Oxford scores, and self-reported questions for satisfaction, less pain and better function were similar but the cemented group had higher KSS clinical scores (96.4 vs. 92.3, P=0.03). More radiolucencies were seen in cementless knees (P<0.001). The cementless group had one revision for instability and one cemented knee was revised for infection. Cementless TKA showed equivalent survivorship (revision for any reason as the endpoint) compared to cemented TKA at this early follow-up. Close monitoring of radiolucencies is important with continued follow-up. Copyright © 2015 Elsevier Inc. All rights reserved.

[Total hip arthroplasty in post-dysplastic hip arthritis. Can type and position of the acetabular component influence longevity of the prosthesis?].

PubMed

Fousek, J; Indráková, P

2007-02-01

The aim of the study was a retrospective evaluation of our patients with post-dysplastic hips treated by cemented or non-cemented total hip arthroplasty (THA) in order to ascertain which type and position of the acetabular component was most effective. In the years 1999-2002, 111 THA procedures were performed in 93 patients, 76 women and 17 men, with post-dysplastic hip arthritis. The average age of the patients at the time of implantation was 52.6 years. On the basis of pre-operative radiographic findings, the patients' conditions were evaluated using the Hartofilakidis classification into three disease categories: dysplasia, low dislocation and high dislocation, and the patients were placed in two groups. Group 1 included 78 patients, and group 2 comprised 26 patients. None of our patients was classified as having high dislocation. Thirty-nine of these patients had previously undergone surgery for dysplastic hips. A total of 104 THAs were evaluated, because radiographic data was incomplete in seven cases. In addition to X-ray findings, the prosthesis type (cemented, hybrid, non-cemented), post-operative complications and signs of loosening were included in the evaluation. Clinical outcomes were assessed by the Harris score. The follow-up terminating on 31st December 2005 was 67 months on the average. In group 1 patients, the average Harris score increased from 38.6 to 80.3 points and in group 2 patients from 35.5 to 84.9 points, mostly with excellent and good results. In 72.1 % of the hips, a press-fit acetabular component was implanted. In 55.8 % of the cases, the acetabular component was implanted off the anatomical center of rotation, into the high hip center, with the range from 9 to 20 mm and an average of 15 mm. The average limb lengthening was 2.5 cm, ranging from 1.0 to 3.5 cm. Our results show that it is more effective to use non-cemented THA for post-dysplastic hips. The implantation of a noncemented acetabular component into the high center provides better covering of the cup with solid bone, without the necessity of cotyloplasty or structural graft use. Also, it does not markedly affect hip function or patients' subjective feelings.

Serum Metal Ion Levels Following Total Hip Arthroplasty With Modular Dual Mobility Components.

PubMed

Matsen Ko, Laura J; Pollag, Kimberley E; Yoo, Joanne Y; Sharkey, Peter F

2016-01-01

Dual mobility acetabular components can reduce the incidence of total hip arthroplasty (THA) instability. Modular dual mobility (MDM) components facilitate acetabular component implantation. However, corrosion can occur at modular junctions. Serum cobalt and chromium levels and Oxford scores were obtained at minimum two year follow-up for 100 consecutive patients who had THA with MDM components. Average Oxford score was 43 (range 13-48). Average serum cobalt and chromium values were 0.7 mcg/L (range, 0.0 to 7.0) and 0.6 mcg/L (range, 0.1 to 2.7), respectively. MARS MRI was performed for four patients with pain and elevated serum cobalt levels. Two of these studies were consistent with adverse local tissue reaction. We recommend use of MDM implants in only patients at high risk for dislocation following THA. Copyright © 2016 Elsevier Inc. All rights reserved.

Measuring the migration of the components and polyethylene wear after total hip arthroplasty: beads and specialised radiographs are not necessary.

PubMed

Devane, P A; Horne, J G; Foley, G; Stanley, J

2017-10-01

This paper describes the methodology, validation and reliability of a new computer-assisted method which uses models of the patient's bones and the components to measure their migration and polyethylene wear from radiographs after total hip arthroplasty (THA). Models of the patient's acetabular and femoral component obtained from the manufacturer and models of the patient's pelvis and femur built from a single computed tomography (CT) scan, are used by a computer program to measure the migration of the components and the penetration of the femoral head from anteroposterior and lateral radiographs taken at follow-up visits. The program simulates the radiographic setup and matches the position and orientation of the models to outlines of the pelvis, the acetabular and femoral component, and femur on radiographs. Changes in position and orientation reflect the migration of the components and the penetration of the femoral head. Validation was performed using radiographs of phantoms simulating known migration and penetration, and the clinical feasibility of measuring migration was assessed in two patients. Migration of the acetabular and femoral components can be measured with limits of agreement (LOA) of 0.37 mm and 0.33 mm, respectively. Penetration of the femoral head can be measured with LOA of 0.161 mm. The migration of components and polyethylene wear can be measured without needing specialised radiographs. Accurate measurement may allow earlier prediction of failure after THA. Cite this article: Bone Joint J 2017;99-B:1290-7. ©2017 The British Editorial Society of Bone & Joint Surgery.

Does vitamin E-blended polyethylene reduce wear in primary total hip arthroplasty: a blinded randomised clinical trial.

PubMed

Scemama, Caroline; Anract, Philippe; Dumaine, Valérie; Babinet, Antoine; Courpied, Jean Pierre; Hamadouche, Moussa

2017-06-01

Some data indicate that first-generation highly cross-linked polyethylene (HXLPE) can oxidise in vivo and is associated with reduced mechanical properties. To overcome these limitations, a natural anti-oxidant vitamin E has been added to HXLPE to preserve the mechanical properties and decrease oxidative degradation whilst conserving high wear resistance. We hypothesised that after a minimal three years of follow-up the use of vitamin E-blended HXLPE would result in lower radiographic wear when compared with ultra-high molecular weight polyethylene (UHMWPE). One hundred patients were randomised to receive hybrid total hip arthroplasty (THA) using a monoblock cementless acetabular component made either of UHMWPE or vitamin E-blended HXLPE. All other parameters were identical in both groups. Complete follow-up was available for 74 of these patients. Femoral head penetration was measured using a validated computer-assisted method. The median creep measured 0.111 mm (range, -0.576 - +0.444 mm) in the vitamin E-blended group versus 0.170 mm (range, -0.861 - +0.884 mm) in the UHMWPE group (difference of medians, 0.059; p = 0.046). The median steady state penetration rate was -0.008 mm/year (range, -0.88 - +0.64 mm/year) in the vitamin E-blended group versus 0.133 mm/year (range, -0.84 - +0.85 mm/year) in the UHMWPE group (difference of medians 0.141, p = 0.043). This study demonstrated that femoral head penetration was lower when using vitamin E-blended HXLPE when compared with UHMWPE, with a steady-state penetration rate far below the osteolysis threshold. Longer-term follow-up is needed to warrant whether wear reduction will generate less occurrence of osteolysis and aseptic loosening.

Comparison of cemented and uncemented fixation in total knee arthroplasty.

PubMed

Brown, Thomas E; Harper, Benjamin L; Bjorgul, Kristian

2013-05-01

As a result of reading this article, physicians should be able to :1. Understand the rationale behind using uncemented fixation in total knee arthroplasty.2.Discuss the current literature comparing cemented and uncemented total knee arthroplasty3. Describe the value of radiostereographic analysis in assessing implant stability.4. Appreciate the limitations in the available literature advocating 1 mode of fixation in total knee arthroplasty. Total knee arthroplasty performed worldwide uses either cemented, cementless, or hybrid (cementless femur with a cemented tibia) fixation of the components. No recent literature review concerning the outcomes of cemented vs noncemented components has been performed. Noncemented components offer the potential advantage of a biologic interface between the bone and implants, which could demonstrate the greatest advantage in long-term durable fixation in the follow-up of young patients undergoing arthroplasty. Several advances have been made in the backing of the tibial components that have not been available long enough to yield long-term comparative follow-up studies. Short-term radiostereographic analysis studies have yielded differing results. Although long-term, high-quality studies are still needed, material advances in biologic fixation surfaces, such as trabecular metal and hydroxyapatite, may offer promising results for young and active patients undergoing total knee arthroplasty when compared with traditional cemented options. Copyright 2013, SLACK Incorporated.

Tribological assessment of a flexible carbon-fibre-reinforced poly(ether-ether-ketone) acetabular cup articulating against an alumina femoral head.

PubMed

Scholes, S C; Inman, I A; Unsworth, A; Jones, E

2008-04-01

New material combinations have been introduced as the bearing surfaces of hip prostheses in an attempt to prolong their life by overcoming the problems of failure due to wear-particle-induced osteolysis. This will hopefully reduce the need for revision surgery. The study detailed here used a hip simulator to assess the volumetric wear rates of large-diameter carbon-fibre-reinforced pitch-based poly(ether-ether-ketone) (CFR-PEEK) acetabular cups articulating against alumina femoral heads. The joints were tested for 25 x 10(6) cycles. Friction tests were also performed on these joints to determine the lubrication regime under which they operate. The average volumetric wear rate of the CFR-PEEK acetabular component of 54 mm diameter was 1.16 mm(3)/10(6) cycles, compared with 38.6 mm(3)/10(6) cycles for an ultra-high-molecular-weight polyethylene acetabular component of 28 mm diameter worn against a ceramic head. This extremely low wear rate was sustained over 25 x 10(6) cycles (the equivalent of up to approximately 25 years in vivo). The frictional studies showed that the joints worked under the mixed-boundary lubrication regime. The low wear produced by these joints showed that this novel joint couple offers low wear rates and therefore may be an alternative material choice for the reduction of osteolysis.

Two- to 4-Year Followup of a Short Stem THA Construct: Excellent Fixation, Thigh Pain a Concern.

PubMed

Amendola, Richard L; Goetz, Devon D; Liu, Steve S; Callaghan, John J

2017-02-01

Short stem cementless femoral components were developed to aid insertion through smaller incisions, preserve metaphyseal bone, and potentially decrease or limit the incidence of thigh pain. Despite some clinical success, the senior author (DDG) believed a higher percentage of his patients who had received a cementless short stem design were experiencing thigh pain, which, coupled with concerns about bone ingrowth fixation, motivated the review of this case series. (1) What is the proportion of patients treated with a short stem cementless THA femoral component that develop thigh pain and what are the hip scores of this population? (2) What are the radiographic results, specifically with respect to bone ingrowth fixation and stress shielding, of this design? (3) Are there particular patient or procedural factors that are associated with thigh pain with this short stem design? Two hundred sixty-one primary THAs were performed in 238 patients by one surgeon between November 2010 and August 2012. During this time period, all patients undergoing primary THA by this surgeon received the same cementless short titanium taper stem. Seven patients (eight hips) died and five patients (five hips) were lost to followup, leaving 226 patients (248 hips) with a mean followup of 3 years (range, 2-5 years). Patients rated their thigh pain during activity or rest at final followup on a 10-point visual analog scale. Harris hip scores (HHS) were obtained at every clinic appointment. Thigh pain was evaluated at the final followup or by contacting the patient by phone. Radiographs were evaluated for bone-implant fixation, bone remodeling, and osteolysis. An attempt was made to correlate thigh pain with patient demographics, implant specifications, or radiographic findings. Seventy-six percent of hips (180 of 238) had no thigh pain, 16% of hips (37 of 238) had mild thigh pain, and 9% (21 of 238) had moderate or severe thigh pain. Preoperatively, mean HHS was 47 (SD, 16) and at last followup, mean HHS was 88 (SD, 13). There were two femoral revisions, one for severe thigh pain and the other for infection. All but two components demonstrated bone ingrowth fixation (99%). Femoral stress shielding was mild in 64% of hips (135 of 212), moderate in 0.5% (one of 212), and severe in no hips. There is an inverse linear relationship between age and severity of thigh pain (r = -0.196; p < 0.0024). Although reliable fixation was achieved and good HHS were attained, the frequency and severity of thigh pain with this short cementless stem were concerning. The surgeon has subsequently abandoned this short stem design and returned to a conventional length stem. Future study direction might investigate the biomechanical grounds for the thigh pain associated with this stem design. Level IV, therapeutic study.

Polyethylene wear debris in modular acetabular prostheses.

PubMed

Chen, P C; Mead, E H; Pinto, J G; Colwell, C W

1995-08-01

The longevity of total hip arthroplasty has brought forth the recognition of aseptic loosening of prosthetic components as the leading cause of implant failure. Modularity of implants, although a significant improvement in versatility, may increase debris formation, a recognized cause of implant failure. This study was designed to measure the relative motion, and to assess the polyethylene wear debris production at the interface between the metal acetabular shell and the back side of the polyethylene liner, in modular hip prostheses. Five models from 4 manufacturers with different locking mechanisms and acetabular shell surface treatments were tested under long-term simultaneous sinusoidal and static loading (10(7) cycles at 3 Hz with +/- 2.5 Nmeter and 220 N static load). Results showed that there were marked differences in the security of the acetabular shell and polyethylene liner locking mechanism, wear pattern, damage sites, and amount of polyethylene debris on the acetabular shell and polyethylene liner surfaces. The range of polyethylene liner motion observed among the 5 models during 1 cycle of testing varied from an average of 0.96 degrees to movement too small to be detected by the test machines. Image and scanning electron microscopy analysis showed different wear patterns and a wide range in the average polyethylene liner surface wear area (0.26 cm2-4.61 cm2). In general, a stable locking mechanism and a smooth acetabular shell surface are essential in minimizing polyethylene liner wear and polyethylene debris production.

Comparison of the risk of revision in cementless total hip arthroplasty with ceramic-on-ceramic and metal-on-polyethylene bearings

PubMed Central

Varnum, Claus; Pedersen, Alma B; Kjærsgaard-Andersen, Per; Overgaard, Søren

2015-01-01

Background and purpose Ceramic-on-ceramic (CoC) bearings were introduced in total hip arthroplasty (THA) to reduce problems related to polyethylene wear. We compared the 9-year revision risk for cementless CoC THA and for cementless metal-on-polyethylene (MoP) THA. Patients and methods In this prospective, population-based study from the Danish Hip Arthroplasty Registry, we identified all the primary cementless THAs that had been performed from 2002 through 2009 (n = 25,656). Of these, 1,773 THAs with CoC bearings and 9,323 THAs with MoP bearings were included in the study. To estimate the relative risk (RR) of revision, we used regression with the pseudo-value approach and treated death as a competing risk. Results 444 revisions were identified: 4.0% for CoC THA (71 of 1,773) and 4.0% for MoP THA (373 of 9,323). No statistically significant difference in the risk of revision for any reason was found for CoC and MoP bearings after 9 years of follow-up (adjusted RR = 1.3, 95% CI: 0.72–2.4). Revision rates due to component failure were 0.5% (n = 8) for CoC bearings and 0.1% (n = 6) for MoP bearings (p < 0.001). 6 patients with CoC bearings (0.34%) underwent revision due to ceramic fracture. Interpretation When compared to the “standard” MoP bearings, CoC THA had a 33% higher (though not statistically significantly higher) risk of revision for any reason at 9 years. PMID:25637339

Use of iPhone technology in improving acetabular component position in total hip arthroplasty.

PubMed

Tay, Xiau Wei; Zhang, Benny Xu; Gayagay, George

2017-09-01

Improper acetabular cup positioning is associated with high risk of complications after total hip arthroplasty. The aim of our study is to objectively compare 3 methods, namely (1) free hand, (2) alignment jig (Sputnik), and (3) iPhone application to identify an easy, reproducible, and accurate method in improving acetabular cup placement. We designed a simple setup and carried out a simple experiment (see Method section). Using statistical analysis, the difference in inclination angles using iPhone application compared with the freehand method was found to be statistically significant ( F [2,51] = 4.17, P = .02) in the "untrained group". There is no statistical significance detected for the other groups. This suggests a potential role for iPhone applications in junior surgeons in overcoming the steep learning curve.

Measuring acetabular component position on lateral radiographs - ischio-lateral method.

PubMed

Pulos, Nicholas; Tiberi Iii, John V; Schmalzried, Thomas P

2011-01-01

The standard method for the evaluation of arthritis and postoperative assessment of arthroplasty treatment is observation and measurement from plain films, using the flm edge for orientation. A more recent employment of an anatomical landmark, the ischial tuberosity, has come into use as orientation for evaluation and is called the ischio-lateral method. In this study, the use of this method was evaluated as a first report to the literature on acetabular component measurement using a skeletal reference with lateral radiographs. Postoperative radiographs of 52 hips, with at least three true lateral radiographs taken at different time periods, were analyzed. Component position was measured with the historical method (using the flm edge for orientation) and with the new method using the ischio-lateral method. The mean standard deviation (SD) for the historical approach was 3.7° and for the ischio-lateral method, 2.2° (p < 0.001). With the historical method, 19 (36.5%) hips had a SD greater than ± 4°, compared to six hips (11.5%) with the ischio-lateral method. By using a skeletal reference, the ischio-lateral method provides a more consistent measurement of acetabular component position. The high intra-class correlation coefficients for both intra- and inter-observer reliability indicate that the angle measured with this simple method, which employs no further technology, increased time, or cost, is consistent and reproducible for multiple observers.

Analysis of migration of press-fit porous-coated acetabular components with medial lucencies using Ein-Bild-Roentegen-Analyse.

PubMed

Sadeghi, Cameron; Gibson, Anthony G; Ries, Michael D

2012-08-01

A total of 136 patients who underwent total hip arthroplasty (154 hips) with press-fit acetabular components were evaluated for the presence of medial radiographic lucencies. Thirty patients (22.1%) demonstrated radiolucencies greater than 1 mm in zone 2 on initial postoperative films. Ein-Bild-Roentegen-Analyse (EBRA) was used to evaluate component migration over a 5-year follow-up period. Migration, measured by EBRA, was not observed during the first 6 months when the radiolucencies were noted to disappear. After 2 years, the mean total migration was 0.8 mm, and at 5 years, it was 1.6 mm. Our results indicate that disappearance of a medial radiolucency seen on early postoperative radiographs is not associated with component migration, which supports the concept that the medial radiolucency fills in with bone or represents bony remodeling around a stable implant. Copyright © 2012 Elsevier Inc. All rights reserved.

The effect of real-time aging on the oxidation and wear of highly cross-linked UHMWPE acetabular liners.

PubMed

Wannomae, Keith K; Christensen, Steven D; Freiberg, Andrew A; Bhattacharyya, Shayan; Harris, William H; Muratoglu, Orhun Kamil

2006-03-01

Irradiation decreases the wear of ultra-high molecular weight polyethylene (UHMWPE) but generates residual free radicals, precursors to long-term oxidation. Melting or annealing is used in quenching free radicals. We hypothesized that irradiated and once-annealed UHMWPE would oxidize while irradiated and melted UHMWPE would not, and that the oxidation in the former would increase wear. Acetabular liners were real-time aged by immersion in an aqueous environment that closely mimicked the temperature and oxygen concentration of synovial fluid. After 95 weeks of real-time aging, once-annealed components were oxidized; the melted components were not. The wear rate of the real-time aged irradiated and once-annealed components was higher than the literature reported values of other contemporary highly cross-linked UHMWPEs. Single annealing after irradiation used with terminal gamma sterilization may adversely affect the long-term oxidative stability of UHMWPE components.

Complications Are Not Increased With Acetabular Revision of Metal-on-metal Total Hip Arthroplasty.

PubMed

Penrose, Colin T; Seyler, Thorsten M; Wellman, Samuel S; Bolognesi, Michael P; Lachiewicz, Paul F

2016-10-01

Isolated revision of the acetabular component in the setting of total hip arthroplasty has an increased risk of dislocation. With local soft tissue destruction frequently associated with failed metal-on-metal (MoM) bearings, it is presumed that acetabular revision of these hips will have even greater risk of complications. However, no study directly compares the complications of MoM with metal-on-polyethylene (MoP) acetabular revisions. In the context of a large database analysis, we asked the following questions: (1) Are there differences in early medical or wound complications after isolated acetabular revision of MoM and MoP bearing surfaces? (2) Are there differences in the frequency of dislocation, deep infection, and rerevision based on the bearing surface of the original implant? A review of the 100% Medicare database from 2005 to 2012 was performed using International Classification of Diseases, 9th Revision and Current Procedural Terminology codes. We identified 451 patients with a MoM bearing and 628 patients with a MoP bearing who had an isolated acetabular revision and a minimum followup of 2 years. The incidence, odds ratios, and 95% confidence intervals for early medical or wound complications were calculated using a univariate analysis at 30 days with patient sex and age group-adjusted analysis for blood transfusion. The incidence, odds ratio, and 95% confidence intervals for dislocation, deep infection, and rerevision were calculated using a univariate analysis at 30 day, 90 days, 1 year, and 2 years using a subgroup analysis with the Cochran-Mantel-Haenszel test to adjust for patient gender and age groups. There were no differences between the MoM and MoP isolated acetabular revisions in the incidence of 30-day local complications. There was a greater risk of transfusion in the MoP group than the MoM group (134 of 451 [30%] versus 230 of 628 [37%]; odds ratio [OR], 0.731; 95% confidence interval [CI], 0.565-0.948; p = 0.018). There were no differences at 2 years between the MoM and MoP acetabular revisions in the incidence of dislocation, infection, or rerevision. When analyzed by patient sex and age group, there were more infections in the age 70 to 79 years MoP group compared with MoM (10 of 451 [5%] versus 29 of 628 [10%]; OR, 4.47; CI, 1.699-11.761; p = 0.001). There were high rates of dislocation, infection, and rerevision in both revision cohorts. The rate of dislocation was not greater after acetabular revision of MoM bearings at 2 years. Based on these findings, clinicians should counsel these patients preoperatively about the risks of these complications. Dual-mobility and constrained components have specific advantages and disadvantages in these settings and should be further studied. Level III, therapeutic study.

Positive effect of removal of subchondral bone plate for cemented acetabular component fixation in total hip arthroplasty: a randomised RSA study with ten-year follow-up.

PubMed

Flivik, G; Kristiansson, I; Ryd, L

2015-01-01

We hypothesised that the removal of the subchondral bone plate (SCBP) for cemented acetabular component fixation in total hip arthroplasty (THA) offers advantages over retention by improving the cement-bone interface, without jeopardising implant stability. We have previously published two-year follow-up data of a randomised controlled trial (RCT), in which 50 patients with primary osteoarthritis were randomised to either retention or removal of the SCBP. The mean age of the retention group (n = 25, 13 males) was 70.0 years (sd 6.8). The mean age in the removal group (n = 25, 16 males) was 70.3 years (sd 7.9). Now we have followed up the patients at six (retention group, n = 21; removal group, n = 20) and ten years (retention group: n = 17, removal group: n = 18), administering clinical outcome questionnaires and radiostereometric analysis (RSA), and determining the presence of radiolucent lines (RLLs) on conventional radiographs. RSA demonstrated similar translation and rotation patterns up to six years. Between six and ten years, proximal acetabular component migration and changes of inclination were larger in the retention group, although the mean differences did not reach statistical significance. Differences in migration were driven by two patients in the SCBP retention group with extensive migration versus none in the SCBP removal group. The significant difference (p < 0.001) in the development of radiolucent lines in the retention group, previously observed at two years, increased even further during the course of follow-up (p < 0.001). While recognising SCBP removal is a more demanding technique, we conclude that, wherever possible, the SCBP should be removed to improve the cement-bone interface in order to maximise acetabular component stability and longevity. ©2015 The British Editorial Society of Bone & Joint Surgery.

21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a snap-fit acetabular component made of an alloy, such as cobalt-chromium-molybdenum, and ultra-high...

21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a snap-fit acetabular component made of an alloy, such as cobalt-chromium-molybdenum, and ultra-high...

21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a snap-fit acetabular component made of an alloy, such as cobalt-chromium-molybdenum, and ultra-high...

The Evolution of the Cup-Cage Technique for Major Acetabular Defects: Full and Half Cup-Cage Reconstruction.

PubMed

Sculco, Peter K; Ledford, Cameron K; Hanssen, Arlen D; Abdel, Matthew P; Lewallen, David G

2017-07-05

Complex acetabular reconstruction for major bone loss can require advanced methods such as the use of a cup-cage construct. The purpose of this study was to review outcomes after the initial development of the cup-cage technique and the subsequent evolution to the use of a half cup-cage construct. We performed a retrospective, single-center review of 57 patients treated with cup-cage reconstruction for major acetabular bone loss. All patients had major acetabular defects graded as Paprosky Type 2B through 3B, with 34 (60%) having an associated pelvic discontinuity. Thirty patients received a full cup-cage construct and 27, a half cup-cage construct. The mean follow-up was 5 years. Both the full and half cup-cage cohorts demonstrated significantly improved Harris hip score (HHS) values, from 36 to 72 at a minimum of 2 years of follow-up (p < 0.05). Early construct migration occurred in 4 patients, with stabilization prior to 2-year follow-up in all but 1 patient. Incomplete, zone-3, nonprogressive acetabular radiolucencies were observed in 2 (7%) of the full cup-cage constructs and 6 (22%) of the half cup-cage constructs. One patient with a full cup-cage construct underwent re-revision of the acetabular component for progressive migration and aseptic loosening. Short-term survivorship free from re-revision for any cause or reoperation was 89% (83% and 96% for full and half cup-cage cohorts, respectively). Both full and half cup-cage constructs demonstrated successful clinical outcomes and survivorship in the treatment of major acetabular defects and pelvic discontinuity. Each method is utilized on the basis of individual intraoperative findings, including the extent and pattern of bone loss, the quality and location of host bone remaining after preparation, and the presence of pelvic discontinuity. Longer-term follow-up is required to understand the durability of these constructs in treating major acetabular defects and pelvic discontinuity. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Preservation of the Acetabular Cup During Revision Total Hip Arthroplasty Using a Novel Mini-navigation Tool: A Case Report.

PubMed

Vincent, John; Alshaygy, Ibrahim; Muir, Jeffrey M; Kuzyk, Paul

2018-01-01

While intraoperative navigation systems have been shown to improve outcomes in primary total hip arthroplasty (THA), their use in the context of revision has been largely overlooked. This case report presents the first documented use of an imageless navigation tool in the context of revision THA, and an unexpected benefit to the surgical procedure as a result. An 84-year-old female patient presented following five episodes of dislocation of the left hip and with pain in the left buttock, groin, and posterior aspect of her hip. Relevant surgical history included primary hip arthroplasty in 1999 and the first revision in 2014. Preoperative analysis revealed a constrained liner that had become disengaged and migrated inferiorly, lodging at the distal aspect of the femoral neck. Acetabular protrusion was also noted. The pre-operative plan included the replacement of the fragmented liner and likely of the acetabular cup due to hardware failure. Intraoperative assessment, however, revealed that the cup was in good condition and would be difficult to remove due to substantial bony ingrowth. With the assistance of imageless navigation, the orientation of the acetabular cup was determined and a new constrained liner was cemented into the preexisting acetabular component at an altered orientation, correcting anteversion by 7°. In revision hip arthroplasty cases, image-based navigation is limited by the presence of existing implants and corresponding metal artefact. This case demonstrates the successful use of an imageless navigation tool for revision surgery. Use of navigation led to the unexpected intraoperative discovery that the acetabular cup was in an acceptable state, and allowed the surgical team to correct the position of the cup using a constrained liner, thus preserving the cup. This significantly benefitted patient outcome, due to the risks associated with the removal of a firmly fixated acetabular cup. While more extensive research is required, this case demonstrates that imageless navigation may be an indispensable tool for revision surgery.

Cementless fixation of "isoelastic" hip endoprostheses manufactured from plastic materials.

PubMed

Morscher, E W; Dick, W

1983-06-01

Nine years of clinical experience with an "isoelastic" shaft prosthesis manufactured using polyacetal resin reveal that for the transmission of forces from the pelvis through the femoral head and neck into the femoral shaft, some rigidity of the proximal part of the prosthesis is necessary. The object is to eliminate micromovements, which lead to bone resorption and implant loosening. However, elasticity greater than that present in metallic implants prevents stress concentrations and disuse stress protection atrophy of the bone. Greater elasticity of the prosthesis, which can be achieved by plastic materials, makes possible a more even, harmonious distribution of the forces transmitted from the implant to the bone and vice versa. A more elastic implant can also act as a better shock absorber than a rigid one. The results in 627 cementless polyethylene cups after a maximum observation period of 5.5 years reveal good incorporation and no aseptic loosening. Especially favorable results occurred in 61 cases by replacing loosened cemented cups with bone grafts and cementless polyethylene cups. On the femoral shaft side too high an elasticity in the proximal part of the prosthesis led to bone resorption and loosening with the first model of the prosthesis. By reinforcing the proximal part of the femoral component, much better results were obtained. The isoelastic femoral shaft, however, is in an early stage of experimentation.

Computer Assisted Surgery and Current Trends in Orthopaedics Research and Total Joint Replacements

NASA Astrophysics Data System (ADS)

Amirouche, Farid

2008-06-01

Musculoskeletal research has brought about revolutionary changes in our ability to perform high precision surgery in joint replacement procedures. Recent advances in computer assisted surgery as well better materials have lead to reduced wear and greatly enhanced the quality of life of patients. The new surgical techniques to reduce the size of the incision and damage to underlying structures have been the primary advance toward this goal. These new techniques are known as MIS or Minimally Invasive Surgery. Total hip and knee Arthoplasties are at all time high reaching 1.2 million surgeries per year in the USA. Primary joint failures are usually due to osteoarthristis, rheumatoid arthritis, osteocronis and other inflammatory arthritis conditions. The methods for THR and TKA are critical to initial stability and longevity of the prostheses. This research aims at understanding the fundamental mechanics of the joint Arthoplasty and providing an insight into current challenges in patient specific fitting, fixing, and stability. Both experimental and analytical work will be presented. We will examine Cementless total hip arthroplasty success in the last 10 years and how computer assisted navigation is playing in the follow up studies. Cementless total hip arthroplasty attains permanent fixation by the ingrowth of bone into a porous coated surface. Loosening of an ingrown total hip arthroplasty occurs as a result of osteolysis of the periprosthetic bone and degradation of the bone prosthetic interface. The osteolytic process occurs as a result of polyethylene wear particles produced by the metal polyethylene articulation of the prosthesis. The total hip arthroplasty is a congruent joint and the submicron wear particles produced are phagocytized by macrophages initiating an inflammatory cascade. This cascade produces cytokines ultimately implicated in osteolysis. Resulting bone loss both on the acetabular and femoral sides eventually leads to component instability. As patients are living longer and total hip arthroplasty is performed in younger patients the risks of osteolysis associated with cumulative wear is increased. Computer-assisted surgery is based on sensing feedback; vision and imaging that help surgeons align the patient's joints during total knee or hip replacement with a degree of accuracy not possible with the naked eye. For the first time, the computer feedback is essential for ligament balancing and longevity of the implants. The computers navigation systems also help surgeons to use smaller incisions instead of the traditional larger openings. Small-incision surgery offers the potential for faster recovery, less bleeding and less pain for patients. The development of SESCAN imaging technique to create a patient based model of a 3D joint will be presented to show the effective solution of complex geometry of joints.

Improving the accuracy of acetabular cup implantation using a bulls-eye spirit level.

PubMed

Macdonald, Duncan; Gupta, Sanjay; Ohly, Nicholas E; Patil, Sanjeev; Meek, R; Mohammed, Aslam

2011-01-01

Acetabular introducers have a built-in inclination of 45 degrees to the handle shaft. With patients in the lateral position, surgeons aim to align the introducer shaft vertical to the floor to implant the acetabulum at 45 degrees. We aimed to determine if a bulls-eye spirit level attached to an introducer improved the accuracy of implantation. A small circular bulls-eye spirit level was attached to the handle of an acetabular introducer. A saw bone hemipelvis was fixed to a horizontal, flat surface. A cement substitute was placed in the acetabulum and subjects were asked to implant a polyethylene cup, aiming to obtain an angle of inclination of 45 degrees. Two attempts were made with the spirit level masked and two with it unmasked. The distance of the air bubble from the spirit level's center was recorded by a single assessor. The angle of inclination of the acetabular component was then calculated. Subjects included both orthopedic consultants and trainees. Twenty-five subjects completed the study. Accuracy of acetabular implantation when using the unmasked spirit level improved significantly in all grades of surgeon. With the spirit level masked, 12 out of 50 attempts were accurate at 45 degrees inclination; 11 out of 50 attempts were "open," with greater than 45 degrees of inclination, and 27 were "closed," with less than 45 degrees. With the spirit level visible, all subjects achieved an inclination angle of exactly 45 degrees. A simple device attached to the handle of an acetabular introducer can significantly improve the accuracy of implantation of a cemented cup into a saw bone pelvis in the lateral position.

Evaluation of a new methodology to simulate damage and wear of polyethylene hip replacements subjected to edge loading in hip simulator testing.

PubMed

Partridge, Susan; Tipper, Joanne L; Al-Hajjar, Mazen; Isaac, Graham H; Fisher, John; Williams, Sophie

2018-05-01

Wear and fatigue of polyethylene acetabular cups have been reported to play a role in the failure of total hip replacements. Hip simulator testing under a wide range of clinically relevant loading conditions is important. Edge loading of hip replacements can occur following impingement under extreme activities and can also occur during normal gait, where there is an offset deficiency and/or joint laxity. This study evaluated a hip simulator method that assessed wear and damage in polyethylene acetabular liners that were subjected to edge loading. The liners tested to evaluate the method were a currently manufactured crosslinked polyethylene acetabular liner and an aged conventional polyethylene acetabular liner. The acetabular liners were tested for 5 million standard walking cycles and following this 5 million walking cycles with edge loading. Edge loading conditions represented a separation of the centers of rotation of the femoral head and the acetabular liner during the swing phase, leading to loading of the liner rim on heel strike. Rim damage and cracking was observed in the aged conventional polyethylene liner. Steady-state wear rates assessed gravimetrically were lower under edge loading compared to standard loading. This study supports previous clinical findings that edge loading may cause rim cracking in liners, where component positioning is suboptimal or where material degradation is present. The simulation method developed has the potential to be used in the future to test the effect of aging and different levels of severity of edge loading on a range of cross-linked polyethylene materials. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1456-1462, 2018. © 2017 Wiley Periodicals, Inc.

A hierarchy of computationally derived surgical and patient influences on metal on metal press-fit acetabular cup failure.

PubMed

Clarke, S G; Phillips, A T M; Bull, A M J; Cobb, J P

2012-06-01

The impact of anatomical variation and surgical error on excessive wear and loosening of the acetabular component of large diameter metal-on-metal hip arthroplasties was measured using a multi-factorial analysis through 112 different simulations. Each surgical scenario was subject to eight different daily loading activities using finite element analysis. Excessive wear appears to be predominantly dependent on cup orientation, with inclination error having a higher influence than version error, according to the study findings. Acetabular cup loosening, as inferred from initial implant stability, appears to depend predominantly on factors concerning the area of cup-bone contact, specifically the level of cup seating achieved and the individual patient's anatomy. The extent of press fit obtained at time of surgery did not appear to influence either mechanism of failure in this study. Copyright © 2012 Elsevier Ltd. All rights reserved.

Managing acetabular fractures in the elderly with fixation and primary arthroplasty: aiming for early weightbearing.

PubMed

Rickman, Mark; Young, James; Trompeter, Alex; Pearce, Rachel; Hamilton, Mark

2014-11-01

Osteoporotic acetabular fractures in the elderly are becoming more common. Regardless of treatment, most patients are managed with a period of protected weightbearing, even if a THA has been performed. We have tried to treat these patients analogously to geriatric femoral neck fractures in a way that allows immediate full weightbearing. We determined return to mobility, length of hospital stay (LOS), radiographic outcomes, and complications in a series of elderly osteoporotic patients treated for acetabular fractures with early fracture fixation and simultaneous THA, allowing full weightbearing immediately postoperatively. Since 2009, one surgeon (MR) used a consistent approach for fracture fixation and THA with immediate weightbearing in all patients older than 65 years with acetabular fractures who were fit for surgery and whose injuries were deemed osteoporotic fractures (low-energy mechanisms) meeting particular radiographic criteria (significant marginal impaction or femoral head damage). Twenty-four patients met these criteria and were reviewed at a mean of 24 months (range, 8-38 months). Mean age was 77 years (range, 63-90 years), and eight patients were women. The surgical technique included plate stabilization of both acetabular columns plus simultaneous THA using a tantalum socket and a cemented femoral stem. Clinical and note reviews were conducted to ascertain return to mobility, LOS, and postoperative complications. Component migration and fracture healing were assessed on plain radiographs. All patients mobilized with full weightbearing by Day 7 postoperatively. Only one patient remained dependent on a frame to mobilize at discharge. At 6 weeks, two patients already required no walking aids. At 6 months, patients were using a single stick at home at most, and all patients had managed stairs. Mean LOS was 18 days (range, 10-36 days). Radiographically, no component migration was seen in any patient. Seventeen of 24 fractures (71%) healed radiographically by 12 weeks, and all healed by 6 months. We recorded one superficial wound infection, one symptomatic deep venous thrombosis, and one in-hospital death from myocardial infarction. Selected older patients with acetabular fractures may be managed using immediate weightbearing after fracture fixation and THA. However, this surgery is complex and requires a mixed skill set. Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Biomechanical evaluation of adjunctive cerclage wire fixation for the prevention of periprosthetic femur fractures using cementless press-fit total hip replacement.

PubMed

Christopher, Scott A; Kim, Stanley E; Roe, Simon; Pozzi, Antonio

2016-08-01

Periprosthetic femoral fractures are a common complication associated with cementless press-fit total hip arthroplasty. The use of prophylactic cerclage wire fixation has been advocated to reduce this complication. The objective of this study was to evaluate whether a double loop cerclage wire, used as adjunctive fixation, increased the peak torsional load to failure in femora implanted with press-fit cementless stems. Peak torsional load to failure was compared between femora without adjunctive fixation and femora receiving a 1 mm double loop cerclage wire placed proximally to the lesser trochanter. Femora treated with adjunctive cerclage wire fixation failed at 20% greater peak torque (P = 0.0001). In conclusion, a double loop cerclage wire may aid in the prevention of periprosthetic fractures associated with press-fit cementless femoral stems. Copyright © 2016. Published by Elsevier Ltd.

Acetabular Morphology: Implications for Joint-preserving Surgery

PubMed Central

Ganz, Reinhold; Impellizzeri, Franco M.; Leunig, Michael

2009-01-01

Appropriate anatomic concepts for surgery to treat femoroacetabular impingement require a precise appreciation of the native acetabular anatomy. We therefore determined (1) the spatial acetabular rim profile, (2) the topography of the articular lunate surface, and (3) the 3-D relationships of the acetabular opening plane comparing 66 bony acetabula from 33 pelves in female and male pelves. The acetabular rim profile had a constant and regular wave-like outline without gender differences. Three prominences anterosuperiorly, anteroinferiorly and posteroinferiorly extended just above hemispheric level. Two depressions were below hemispheric level, of 9° at the anterior wall and of 21° along the posterosuperior wall. In 94% of all acetabula, the deepest extent of the articular surface was within 30° of the anterosuperior acetabular sector. In 99% of men and in 91% of women, the depth of the articular surface was at least 55° along almost half of the upper acetabular cup. The articular surface was smaller in women than in men. The acetabular opening plane was orientated in 21° ± 5° for version, 48° ± 4° for inclination and 19° ± 6° for acetabular tilt with no gender differences. We defined tilt as forward rotation of the entire acetabular cup around its central axis; because of interindividual variability of acetabular tilt, descriptions of acetabular lesions during surgery, CT scanning and MRI should be defined and recorded in relation to the acetabular notch. Acetabular tilt and pelvic tilt should be separately identified. We believe this information important for surgeons performing rim trimming in FAI surgery or performing acetabular osteotomies. PMID:19130159

Primary total hip arthroplasty in Catalonia: What is the clinical evidence that supports our prosthesis?

PubMed

Chaverri-Fierro, D; Lobo-Escolar, L; Espallargues, M; Martínez-Cruz, O; Domingo, L; Pons-Cabrafiga, M

The implementation of National Prostheses Registries allows us to obtain a large amount of data and make conclusions in order to improve the use of them. Sweden was the first country to implement a National Prostheses Registry in 1979. Catalonia has been doing this since 2005. The aim of our study is to analyse the evidence that supports primary total hip replacement in Catalonia in the last 9 years, based on the Arthroplasty Registry of Catalonia (RACat). A review of the literature was carried out of the prosthesis (acetabular cups/stems) reported in the RACat between the period 2005 to 2013 in the following databases: ODEP (Orthopaedic Data Evaluation Panel), TRIP database, PubMed, and Google Scholar. Those prostheses implanted in less than 10 units (182 acetabular components corresponding to 49 models/228 stems corresponding to 63 models) were excluded. A total of 18,634 (99%) implanted acetabular cups were analysed out of a total number of 18,816, corresponding to 74 different models. In 18 models (2527 acetabular cups) no clinical evidence to support its use was found. An analysis was performed on 19,367 (98.84%) out of a total number of 19,595 implanted stems, corresponding to 75 different models. In 16 models (1845 stems) no clinical evidence was found to support their use. Variable evidence was found in the 56 models of acetabular cups (16,107) and 59 models of stems (17,522), most of it corresponding to level iv clinical evidence. There was a significant number implanted prostheses evaluated (13.56% acetabular cups/9.5% stems) for which no clinical evidence was found. The elevated number of models is highlighted (49 types for acetabular cups/63 types for stems) with less than 10 units implanted, which corresponds to only 1% of the total implants. The use of arthroplasty registers is shown to be an extremely helpful tool that allows analyses and conclusions to be made for the follow-up and post-marketing surveillance period. Copyright © 2016 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Post-deformation shape-recovery behavior of vitamin E-diffused, radiation crosslinked polyethylene acetabular components.

PubMed

Takahashi, Yasuhito; Tateiwa, Toshiyuki; Shishido, Takaaki; Masaoka, Toshinori; Kubo, Kosuke; Yamamoto, Kengo

2016-10-01

The in-vivo progression of creep and wear in ultra-high molecular weight polyethylene (UHMWPE) acetabular liners has been clinically evaluated by measuring radiographic penetration of femoral heads. In such clinical assessments, however, viscoelastic strain relaxation has been rarely considered after a removal of hip joint loading, potentially leading to an underestimation of the penetrated thickness. The objective of this study was to investigate shape-recovery behavior of pre-compressed, radiation crosslinked and antioxidant vitamin E-diffused UHMWPE acetabular liners, and also to characterize the effects of varying their internal diameter (ID) and wall thickness (WT). We applied uniaxial compression to the UHMWPE specimens of various ID (28, 32, 36mm) and WT (4.8, 6.8, 8.9mm) for 4320min under the constant load of 3000N, and subsequently monitored the strain-relaxation behavior as a function of time after unloading. It was observed that there was a considerable shape recovery of the components after removal of the external static load. Reducing ID and WT significantly accelerated the rate of creep strain recovery, and varying WT was more sensitive to the recovery behavior than ID. Creep deformation of the tested liners recovered mostly within the first 300min after unloading. Note that approximately half of the total recovery amount proceeded just within 5min after unloading. These results suggest a remarkably high capability of shape recovery of vitamin E-diffused highly crosslinked UHMWPE. In conclusion, the time-dependent shape recovering and the diameter-thickness effect on its behavior should be carefully considered when the postoperative penetration is quantified in highly crosslinked UHMWPE acetabular liners (especially on the non-weight bearing radiographs). Copyright © 2016 Elsevier Ltd. All rights reserved.

Early experience with dual mobility acetabular systems featuring highly cross-linked polyethylene liners for primary hip arthroplasty in patients under fifty five years of age: an international multi-centre preliminary study.

PubMed

Epinette, Jean-Alain; Harwin, Steven F; Rowan, Fiachra E; Tracol, Philippe; Mont, Michael A; Chughtai, Morad; Westrich, Geoffrey H

2017-03-01

To evaluate early performance of contemporary dual mobility acetabular systems with second generation annealed highly cross-linked polyethylene for primary hip arthroplasty of patients under 55 years of age. A prospective observational five years study across five centers in Europe and the USA of 321 patients with a mean age of 48.1 years was performed. Patients were assessed for causes of revision, hip instability, intra-prosthetic dissociation, Harris hip score and radiological signs of osteolysis. There were no dislocations and no intra-prosthetic dissociations. Kaplan Meier analysis demonstrated 97.51% survivorship for all cause revision and 99.68% survivorship for acetabular component revision at five years. Mean Harris hip score was 93.6. Two acetabular shells were revised for neck-rim implant impingement without dislocation and ten femoral stems were revised for causes unrelated to dual mobility implants. Contemporary highly cross-linked polyethylene dual mobility systems demonstrate excellent early clinical, radiological, and survivorship results in a cohort of patients that demand high performance from their implants. It is envisaged that DM and second generation annealed HXLPE may reduce THA instability and wear, the two most common causes of THA revision in hip arthroplasty.

Retrieval analysis of ceramic-coated metal-on-polyethylene total hip replacements.

PubMed

Khatkar, Harman; Hothi, Harry; de Villiers, Danielle; Lausmann, Christian; Kendoff, Daniel; Gehrke, Thorsten; Skinner, John; Hart, Alister

2017-06-01

Ceramic coatings have been used in metal-on-polyethylene (MOP) hips to reduce the risk of wear and also infection; the clinical efficacy of this remains unclear. This retrieval study sought to better understand the performance of coated bearing surfaces. Forty-three coated MOP components were analysed post-retrieval for evidence of coating loss and gross polyethylene wear. Coating loss was graded using a visual semi-quantitative protocol. Evidence of gross polyethylene wear was determined by radiographic analysis and visual inspection of the retrieved implants. All components with gross polyethylene wear (n = 10) were revised due to a malfunctioning acetabular component; 35 % (n = 15) of implants exhibited visible coating loss and the incidence of polyethylene wear in samples with coating loss was 54 %, significantly (p = 0.02) elevated compared to samples with intact coatings (14 %). In this study we found evidence of coating loss on metal femoral heads which was associated with increased wear of the corresponding polyethylene acetabular cups.

Acetabular Cup Revision.

PubMed

Kim, Young-Ho

2017-09-01

The use of acetabular cup revision arthroplasty is on the rise as demands for total hip arthroplasty, improved life expectancies, and the need for individual activity increase. For an acetabular cup revision to be successful, the cup should gain stable fixation within the remaining supportive bone of the acetabulum. Since the patient's remaining supportive acetabular bone stock plays an important role in the success of revision, accurate classification of the degree of acetabular bone defect is necessary. The Paprosky classification system is most commonly used when determining the location and degree of acetabular bone loss. Common treatment options include: acetabular liner exchange, high hip center, oblong cup, trabecular metal cup with augment, bipolar cup, bulk structural graft, cemented cup, uncemented cup including jumbo cup, acetabular reinforcement device (cage), trabecular metal cup cage. The optimal treatment option is dependent upon the degree of the discontinuity, the amount of available bone stock and the likelihood of achieving stable fixation upon supportive host bone. To achieve successful acetabular cup revision, accurate evaluation of bone defect preoperatively and intraoperatively, proper choice of method of acetabular revision according to the evaluation of acetabular bone deficiency, proper technique to get primary stability of implant such as precise grafting technique, and stable fixation of implant are mandatory.

Overdiagnosing of femoroacetabular impingement: correlation between clinical presentation and computed tomography in symptomatic patients☆

PubMed Central

Canella, Richard Prazeres; Adam, Guilherme Pradi; de Castillo, Roberto André Ulhôa; Codonho, Daniel; Ganev, Gerson Gandhi; de Vicenzi, Luiz Fernando

2016-01-01

Objective To correlate the angles between the acetabulum and the proximal femur in symptomatic patients with femoroacetabular impingement (FAI), using computed tomography (CT). Methods We retrospectively evaluated 103 hips from 103 patients, using multislice CT to measure the acetabular age, acetabular version (in its supraequatorial portion and in its middle third), femoral neck version, cervical-diaphyseal and alpha angles and the acetabular depth. For the statistical analysis, we used the Pearson correlation coefficient. Results There were inverse correlations between the following angles: (1) acetabular coverage versus alpha angle (p = 0.019); (2) acetabular version (supraequatorial) versus alpha angle (p = 0.049). For patients with femoral anteversion lower than 15 degrees: (1) acetabular version (supraequatorial) versus alpha angle (p = 0.026); (2) acetabular version (middle third) versus alpha angle (p = 0.02). For patients with acetabular version (supraequatorial) lower than 10 degrees: (1) acetabular version (supraequatorial) versus alpha angle (p = 0.004); (2) acetabular version (middle third) versus alpha angle (p = 0.009). Conclusion There was a statistically significant inverse correlation between the acetabular version and alpha angles (the smaller the acetabular anteversion angle was, the larger the alpha angle was) in symptomatic patients, thus supporting the hypothesis that FAI occurs when cam and pincer findings due to acetabular retroversion are seen simultaneously, and that the latter alone does not cause FAI, which leads to overdiagnosis in these cases. PMID:27069890

Overdiagnosing of femoroacetabular impingement: correlation between clinical presentation and computed tomography in symptomatic patients.

PubMed

Canella, Richard Prazeres; Adam, Guilherme Pradi; de Castillo, Roberto André Ulhôa; Codonho, Daniel; Ganev, Gerson Gandhi; de Vicenzi, Luiz Fernando

2016-01-01

To correlate the angles between the acetabulum and the proximal femur in symptomatic patients with femoroacetabular impingement (FAI), using computed tomography (CT). We retrospectively evaluated 103 hips from 103 patients, using multislice CT to measure the acetabular age, acetabular version (in its supraequatorial portion and in its middle third), femoral neck version, cervical-diaphyseal and alpha angles and the acetabular depth. For the statistical analysis, we used the Pearson correlation coefficient. There were inverse correlations between the following angles: (1) acetabular coverage versus alpha angle (p = 0.019); (2) acetabular version (supraequatorial) versus alpha angle (p = 0.049). For patients with femoral anteversion lower than 15 degrees: (1) acetabular version (supraequatorial) versus alpha angle (p = 0.026); (2) acetabular version (middle third) versus alpha angle (p = 0.02). For patients with acetabular version (supraequatorial) lower than 10 degrees: (1) acetabular version (supraequatorial) versus alpha angle (p = 0.004); (2) acetabular version (middle third) versus alpha angle (p = 0.009). There was a statistically significant inverse correlation between the acetabular version and alpha angles (the smaller the acetabular anteversion angle was, the larger the alpha angle was) in symptomatic patients, thus supporting the hypothesis that FAI occurs when cam and pincer findings due to acetabular retroversion are seen simultaneously, and that the latter alone does not cause FAI, which leads to overdiagnosis in these cases.

[Prophylactic osteotomy of pelvis in dysplastic acetabulum.].

PubMed

Richtr, M; Sosna, A

1998-01-01

Acetabular dysplasia and anatomical changes of pelvis accompanied with gracility of iliac bone pose a problem for a reliable fixation of acetabular component. In extreme cases the bone stock is not sufficient to accommodate the smallest size of the cup. Sometimes even reaming of the bed down to lamina interna is not sufficient for an adequate covering of the implant. Consequently, weakening of the bottom of acetabulum may be not only one of the causes of the failure of the implant but it makes difficult also the following revision surgeries. Therefore in acetabular dysplasia the authors recommend acetabuloplasty of the bottom of acetabulum preserving its original thickness including inner cortex. They recommend to perform osteotomy of the full thickness of the medial wall of acetabulum and move the massive bone graft created in this way farther into pelvis. At the same time they take care to preserve blood supply of the bone graft by retaining corticoperiostal bridge by means of osteoclasia. The suggested procedure allows full coverage of the implant by iliac bone and at the same time preserves a firm support of acetabular fossa. The original thickness of the medial wall of acetabulum is considered by authors as a significant antimigration barrier. In the period 1991 -1994 the authors used this method at Ist Orthopaedic Clinic of 1st Medical Faculty, Charles University in Prague in total in 16 patients. In all of them after 6 months the bone graft was fully absorbed. Remodelling of the bone graft occurred 1 to 2 years after the surgery and after that the thickness of the graft remained the same. Neither any change of the structure nor reduction of the thickness of the graft was found between 3rd and 4th year after the surgery. The nature of trabecular remodelling of the bone graft corresponds to the transfer of forces in loading the graft by acetabular cup. Key words: acetabuloplasty, osteotomy of the medial wall of acetabulum, osteotomy of pelvis, THR, acetabular dysplasia.

An integrated CAD/CAM/robotic milling method for custom cementless femoral prostheses.

PubMed

Wen-ming, Xi; Ai-min, Wang; Qi, Wu; Chang-hua, Liu; Jian-fei, Zhu; Fang-fang, Xia

2015-09-01

Aseptic loosening is the primary cause of cementless femoral prosthesis failure and is related to the primary stability of the cementless femoral prosthesis in the femoral cavity. The primary stability affects both the osseointegration and the long-term stability of cementless femoral prostheses. A custom cementless femoral prosthesis can improve the fit and fill of the prosthesis in the femoral cavity and decrease the micromotion of the proximal prosthesis such that the primary stability of the custom prosthesis can be improved, and osseointegration of the proximal prosthesis is achieved. These results will help to achieve long-term stability in total hip arthroplasty (THA). In this paper, we introduce an integrated CAD/CAM/robotic method of milling custom cementless femoral prostheses. The 3D reconstruction model uses femoral CT images and 3D design software to design a CAD model of the custom prosthesis. After the transformation matrices between two units of the robotic system are calibrated, consistency between the CAM software and the robotic system can be achieved, and errors in the robotic milling can be limited. According to the CAD model of the custom prosthesis, the positions of the robotic tool points are produced by the CAM software of the CNC machine. The normal vector of the three adjacent robotic tool point positions determines the pose of the robotic tool point. In conclusion, the fit rate of custom pig femur stems in the femoral cavities was 90.84%. After custom femoral prostheses were inserted into the femoral cavities, the maximum gaps between the prostheses and the cavities measured less than 1 mm at the diaphysis and 1.3 mm at the metaphysis. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Hip arthroplasty today and tomorrow.

PubMed

Amstutz, H C

1987-12-01

Acrylic-fixed total hip and surface replacement arthroplasty have been very effective in affording immediate relief of pain and providing improved function. Complications have been reduced by improvements in design, materials, and especially technique. They are now very low in the elderly, and the stem type acrylic-fixed design remains the procedure of choice. The failure rates in youthful patients and those with bone-stock deficiencies have been high in both THR and surface types, although the latter had the advantage of preserving femoral stock. On the femoral side, the new "macro" femoral designs from Europe and "micro" femoral porous designs have shown promise, but thigh pain, incomplete and difficult to predict bone ingrowth patterns, coupled with removal problems have influenced design and technique changes. Both press-fit stem types and porous surface replacements have produced promising initial results with less potential downside risks. On the acetabular side, both the cementless hemispherical with screw-type adjuvant fixation, or the chamfered cylinder designs, used primarily with the UCLA porous surface replacements, but also with stem-type devices, appear to achieve best short-term results, while the entire variety of screw rings are disappointing. The future will bring further refinements in technique and specific indications for certain types of replacement stem in specific types of bone stock deficiencies. The all ceramic-ceramic and ceramic-polyethylene bearings show promise of reducing wear and, hence, should improve longevity of implant fixation.

The design and development of a triaxial wear-testing joint simulator.

PubMed

Green, A S; O'Connell, M K; Lyons, A S; James, S P

1999-01-01

Most of the existing wear testers created to wear test total hip replacements, specifically the acetabular component, are designed to exert only an axial force and provide rotation in a close approximation of the actual femoral movement. The Rocky Mountain Joint Simulator was designed to exert three orthogonal forces and provide rotations about the X-, Y- and Z-axes to more closely simulate the physiological forces and motions found in the human gait cycle. The RMJS was also designed with adaptability for other joints, such as knees or canine hips, through the use of hydraulics and a computer-programmable control system. Such adaptability and functionality allows the researcher to more closely model a gait cycle, thereby obtaining wear patterns that resemble those found in retrieved implants more closely than existing simulators. Research is ongoing into the tuning and evaluation of the machine and preliminary acetabular component wear test results will be presented at the conference.

Mid-term results of total knee arthroplasty with a porous tantalum monoblock tibial component.

PubMed

Hayakawa, Kazue; Date, Hideki; Tsujimura, Shunzo; Nojiri, Sho; Yamada, Harumoto; Nakagawa, Kenji

2014-01-01

The objectives of the present study were to assess the mid-term results of cementless total knee arthroplasty (TKA) with the porous tantalum monoblock tibial component and to examine the time course of bone changes on plain radiographs. The subjects were 32 patients, 29 patients were available for follow-up. We investigated the mid-term results of TKA after a mean follow-up period of 7 years and 8 months. We also examined changes of the bone over time on plain radiographs. The Knee Society Clinical Rating scores showed significant improvement. Bone changes around the tibial component were as follows: new bone formation and longitudinal trabecular thickening in 41.4% (Type A), only longitudinal trabecular thickening in 41.4% (Type B), and no changes in 17.2% (Type C). Type A and B changes were more frequent in patients with osteoarthritis, whereas Type C was only seen in patients with rheumatoid arthritis. Three knees had an initial gap, but this disappeared in all cases, and no new radiolucent lines were detected. Stress shielding was observed in seven knees (21.9%), but there was no implant loosening related to it. When we examined the relationship between the mechanical axis and the locations of the tips of the tibial pegs in patients with or without stress shielding, no significant differences were found. The results of mid-term follow-up have demonstrated favorable bone ingrowth, suggesting that porous tantalum is a promising material for cementless TKA. © 2013.

Ceramic bearings with bilayer coating in cementless total hip arthroplasty. A safe solution. A retrospective study of one hundred and twenty six cases with more than ten years' follow-up.

PubMed

Ferreira, André; Aslanian, Thierry; Dalin, Thibaud; Picaud, Jean

2017-05-01

Using a ceramic-ceramic bearings, cementless total hip arthroplasty (THA) has provided good clinical results. To ensure longevity a good quality fixation of the implants is mandatory. Different surface treatments had been used, with inconsistent results. We hypothesized that a "bilayer coating" applied to both THA components using validated technology will provide a long-lasting and reliable bone fixation. We studied the survival and bone integration of a continuous, single-surgeon, retrospective series of 126 THA cases (116 patients) with an average follow-up of 12.2 years (minimum 10 years). The THA consisted of cementless implants with a bilayer coating of titanium and hydroxyapatite and used a ceramic-ceramic bearing. With surgical revision for any cause (except infection) as the end point, THA survival was 95.1 % at 13 years. Stem (98.8 %) and cup (98.6 %) survival was similar at 13 years. Bone integration was confirmed in 100 % of implants (Engh-Massin score of 17.42 and ARA score of 5.94). There were no instances of loosening. Revisions were performed because of instability (1.6 %), prosthetic impingement or material-related issues. A bilayer titanium and hydroxyapatite coating provides strong, fast, reliable osseo integration, without deterioration at the interface or release of damaging particles. The good clinical outcomes expected of ceramic bearings were achieved, as were equally reliable stem and cup fixation.

Acetabular-epiphyseal angle and hip dislocation in cerebral palsy: a preliminary study.

PubMed

Alí-Morell, O J; Zurita-Ortega, F; Davó-Jiménez, I; Segura-Biedma, S

To relate, in non-ambulatory subjects with palsy, Reimers' migration percentage with standardized radiological measurements, including the acetabular-epiphyseal angle. Descriptive, observational and transversal study of 15 individuals with cerebral palsy at levels IV and V of the Gross Motor Function Classification System, aged between 3 and 9 years. Radiological measurements of the acetabular index, Hilgenreiner's epiphyseal angle, acetabular-epiphyseal angle, neck-shaft angle and Reimers' migration percentage of each of the hips were performed. Correlations between acetabular index, epiphyseal angle and acetabular-epiphyseal angle were obtained with respect to the Reimers migration percentage. For hips with a migration rate of 15% or less, a positive correlation was observed between acetabular and epiphyseal angles. In our population, the measurement between acetabular and epiphyseal inclination represents the highest association with the hip migration percentage. Copyright © 2018 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

Fretting and Corrosion at the Backside of Modular Cobalt Chromium Acetabular Inserts: A Retrieval Analysis.

PubMed

Tarity, T David; Koch, Chelsea N; Burket, Jayme C; Wright, Timothy M; Westrich, Geoffrey H

2017-03-01

Adverse local tissue reaction formation has been suggested to occur with the Modular Dual Mobility (MDM) acetabular design. Few reports in the literature have evaluated fretting and corrosion damage between the acetabular shell and modular metal inserts in this modular system. We evaluated a series of 18 retrieved cobalt chromium MDM inserts for evidence of fretting and corrosion. We assessed the backsides of 18 MDM components for evidence of fretting and corrosion in polar and taper regions based on previously established methods. We collected and assessed 30 similarly designed modular inserts retrieved from metal-on-metal (MoM) total hip arthroplasties as a control. No specific pattern of fretting or corrosion was identified on the MDM inserts. Both fretting and corrosion were significantly greater in the MoM cohort than the MDM cohort, driven by higher fretting and corrosion scores in the engaged taper region of the MoM inserts. MoM components demonstrated more fretting and corrosion than MDM designs, specifically at the taper region, likely driven by differences in the taper engagement mechanism and geometry among the insert designs. The lack of significant fretting and corrosion observed in the MDM inserts are inconsistent with recent claims that this interface may produce clinically significant metallosis and adverse local tissue reactions. Copyright © 2016 Elsevier Inc. All rights reserved.

Intra-operative digital imaging: assuring the alignment of components when undertaking total hip arthroplasty.

PubMed

Hambright, D; Hellman, M; Barrack, R

2018-01-01

The aims of this study were to examine the rate at which the positioning of the acetabular component, leg length discrepancy and femoral offset are outside an acceptable range in total hip arthroplasties (THAs) which either do or do not involve the use of intra-operative digital imaging. A retrospective case-control study was undertaken with 50 patients before and 50 patients after the integration of an intra-operative digital imaging system in THA. The demographics of the two groups were comparable for body mass index, age, laterality and the indication for surgery. The digital imaging group had more men than the group without. Surgical data and radiographic parameters, including the inclination and anteversion of the acetabular component, leg length discrepancy, and the difference in femoral offset compared with the contralateral hip were collected and compared, as well as the incidence of altering the position of a component based on the intra-operative image. Digital imaging took a mean of five minutes (2.3 to 14.6) to perform. Intra-operative changes with the use of digital imaging were made for 43 patients (86%), most commonly to adjust leg length and femoral offset. There was a decrease in the incidence of outliers when using intra-operative imaging compared with not using it in regard to leg length discrepancy (20% versus 52%, p = 0.001) and femoral offset inequality (18% versus 44%, p = 0.004). There was also a difference in the incidence of outliers in acetabular inclination (0% versus 7%, p = 0.023) and version (0% versus 4%, p = 0.114) compared with historical results of a high-volume surgeon at the same centre. The use of intra-operative digital imaging in THA improves the accuracy of the positioning of the components at THA without adding a substantial amount of time to the operation. Cite this article: Bone Joint J 2018;100B(1 Supple A):36-43. ©2018 The British Editorial Society of Bone & Joint Surgery.

Evaluation of the three-dimensional bony coverage before and after rotational acetabular osteotomy.

PubMed

Tanaka, Takeyuki; Moro, Toru; Takatori, Yoshio; Oshima, Hirofumi; Ito, Hideya; Sugita, Naohiko; Mitsuishi, Mamoru; Tanaka, Sakae

2018-02-26

Rotational acetabular osteotomy is a type of pelvic osteotomy that involves rotation of the acetabular bone to improve the bony coverage of the femoral head for patients with acetabular dysplasia. Favourable post-operative long-term outcomes have been reported in previous studies. However, there is a paucity of published data regarding three-dimensional bony coverage. The present study investigated the three-dimensional bony coverage of the acetabulum covering the femoral head in hips before and after rotational acetabular osteotomy and in normal hips. The computed tomography data of 40 hip joints (12 joints before and after rotational acetabular osteotomy; 16 normal joints) were analyzed. The three-dimensional bony coverage of each joint was evaluated using original software. The post-operative bony coverage improved significantly compared with pre-operative values. In particular, the anterolateral aspect of the acetabulum tended to be dysplastic in patients with acetabular dysplasia compared to those with normal hip joints. However, greater bony coverage at the anterolateral aspect was obtained after rotational acetabular osteotomy. Meanwhile, the results of the present study may indicate that the bony coverage in the anterior aspect may be excessive. Three-dimensional analysis indicated that rotational acetabular osteotomy achieved favorable bony coverage. Further investigations are necessary to determine the ideal bony coverage after rotational acetabular osteotomy.

Reconstruction of the pelvic brim and its role in the reduction accuracy of displaced T-shaped acetabular fracture.

PubMed

Harnroongroj, T; Asavamongkolkul, A; Chareancholvanich, K

2000-05-01

Open reduction of the displaced T-shaped acetabular fracture has a problem of accuracy of the fracture reduction. This study was carried out to demonstrate that the reconstruction of the pelvic brim by approaching the pubo-acetabular fragment plays a role in the accuracy of the reduction of displaced T-shaped acetabular fractures. From 1975 to 1990, a retrospective study was carried out of 22 patients who sustained a displaced T-shaped acetabular fracture. The patients were operated on by open reduction and internal fixation of the ischio-acetabular fragment to the posterior column without restoration of the pelvic brim. Radiographs of the pelvis were reviewed. The result showed that there was displacement of the pubo-acetabular fragment including the medial wall in all cases. As the result of this study, a prospective study between 1990 and 1997 was carried out of 15 patients who sustained displaced T-shaped acetabular fractures including 3 cases with medial displacement of the femoral head. The pubo-acetabular fragment was anatomically reduced and fixed to the anterior column of the acetabulumn as the first approach to restore a disrupted pelvic brim. There, patterns of the acetabular fracture were subsequently re-evaluated especially the ischio-acetabular fragment including the position of the femoral head by using an intraoperative portable X-ray technique. The stability of the hip joint was assessed by hip flexion. The intraoperative radiograph appearances of the ischio-acetabular fragment were visually confirmed by a second surgical exposure. The results showed that the intraoperative radiographs gave spontaneous reduction of the ischio-acetabular fragment in all patients except one. There was a reduction of the displaced femoral head into the hip socket in the three patients. The hip joints were stable in all patients. The second surgical exposure showed that there was good spontaneous reduction of the ischio-acetabular fragment to the posterior column by ligamentotaxis in 14 patients. Therefore, it is not necessary to address the ischio-acetabular fragment. In the exceptional case, the ischio-acetabular fragment was displaced as a free bone which could not be reduced by ligamentotaxis. However, reduction and internal fixation of the ischio-acetabular fragment to the posterior column for complete re-application of the hip joint onto the pelvic ring of this case was facilitated. Postoperative 2 year and 5 year follow-up showed that the fracture had healed without heterotrophic ossification or premature osteoarthrosis of the hip joint. The exceptional case had a broken plate at the anterior column of the acetabulum. Hip function was evaluated clinically using Merle D' Aubigne's hip score. All patients had a "very good score". The study showed that reconstruction of the pelvic brim by anatomical reduction and fixation of the pubo-acetabular fragment to the anterior column plays an important role in the accuracy of fracture reduction of a displaced T-shaped acetabular fracture.

Estimated survival probability of the Spotorno total hip arthroplasty after a 15- to 21-year follow-up: one surgeon's results.

PubMed

Terré, Ricardo A

2010-01-01

We retrospectively assess 171 consecutive total hip arthroplasties (THAs) with a Spotorno CLS uncemented prosthesis implanted through a Hardinge approach. The mean follow-up was 17.9 years. All consecutive operations were performed by 1 surgeon. Eight patients had been lost to follow-up, and 77 had died for unrelated causes. Overall, 4 stems and 19 cups underwent revision. The cumulative survival rate at 21 years was 79.02% (95% confidence interval [95% CI], 45.98-100.00%) for the acetabular component and 96.71% (95% CI, 60.71-100.00%) for the stem. We can conclude that failure of the Spotorno CLS THA is mainly due to its acetabular component (relative risk 4.5). Survival results for the Spotorno CLS stem exceed the patients? life expectancies in the 60- to 70-year-old population in our area. Loosening with or without fatigue fracture of the component and the learning curve for proper implantation have been the main causes for the expansion cup failure.

Preliminary application of computer-assisted patient-specific acetabular navigational template for total hip arthroplasty in adult single development dysplasia of the hip.

PubMed

Zhang, Yuan Z; Chen, Bin; Lu, Sheng; Yang, Yong; Zhao, Jian M; Liu, Rui; Li, Yan B; Pei, Guo X

2011-12-01

The considerable variation in anatomical abnormalities of hip joints associated with different types of developmental dysplasia of hip (DDH) makes reconstruction in total hip arthroplasty (THA) difficult. It is desirable to create patient-specific designs for THA procedures. In the cases of adult single DDH, an accuracy-improved method has been developed for acetabular cup prosthesis implantation of hip arthroplasty. From October 2007 to November 2008, 22 patients with single DDH (according to the Crowe standard, all dysplasia hips were classified as type I) were scanned with spiral CT pre-operatively. These patients scheduled for THA were randomly assigned to undergo either conventional THA (control group, n = 11) or navigation template implantation (NT group, n = 11). In the NT group, three-dimensional (3D) CT pelvis image data were transferred to a computer workstation and 3D models of the hip were reconstructed using the Mimics software. The 3D models were then processed by the Imageware software. In brief, a template that best fitted the location and shape of the acetabular cup was 'reversely' built from the 3D model, the rotation centre of the pathological hip determined by mirroring that of the healthy site, and a guiding hole in the template was then designed. The navigational templates were manufactured using a rapid prototyping machine. These navigation templates guide acetabular component placement. Based on the predetermined abduction angle 45° and anteversion angle 18°, after 1 year follow-up, the NT group showed significantly smaller differences (1.6° ± 0.4°, 1.9° ± 1.1°) from the predetermined angles than those in the control group (5.8° ± 2.9°, 3.9° ± 2.5°) (P < 0.05). The template designs facilitated accurate placement of acetabular components in dysplasia of acetabulum. The hip's center of rotation in DDH could be established using computer-aided design, which provides a useful method for the accurate location of prosthesis with a low cost-performance ratio without excessive technical workload on the surgical team. Copyright © 2011 John Wiley & Sons, Ltd.

21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint (hemi-hip) acetabular metal cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3370 Hip joint (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip) acetabular...

21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint (hemi-hip) acetabular metal cemented... (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip) acetabular metal cemented prosthesis is a device intended to be implanted to replace a portion of the hip joint...

Three-dimensional finite analysis of acetabular contact pressure and contact area during normal walking.

PubMed

Wang, Guangye; Huang, Wenjun; Song, Qi; Liang, Jinfeng

2017-11-01

This study aims to analyze the contact areas and pressure distributions between the femoral head and mortar during normal walking using a three-dimensional finite element model (3D-FEM). Computed tomography (CT) scanning technology and a computer image processing system were used to establish the 3D-FEM. The acetabular mortar model was used to simulate the pressures during 32 consecutive normal walking phases and the contact areas at different phases were calculated. The distribution of the pressure peak values during the 32 consecutive normal walking phases was bimodal, which reached the peak (4.2 Mpa) at the initial phase where the contact area was significantly higher than that at the stepping phase. The sites that always kept contact were concentrated on the acetabular top and leaned inwards, while the anterior and posterior acetabular horns had no pressure concentration. The pressure distributions of acetabular cartilage at different phases were significantly different, the zone of increased pressure at the support phase distributed at the acetabular top area, while that at the stepping phase distributed in the inside of acetabular cartilage. The zones of increased contact pressure and the distributions of acetabular contact areas had important significance towards clinical researches, and could indicate the inductive factors of acetabular osteoarthritis. Copyright © 2016. Published by Elsevier Taiwan.

Validation of a new radiographic measurement of acetabular version: the transverse axis distance (TAD).

PubMed

Nitschke, Ashley; Lambert, Jeffery R; Glueck, Deborah H; Jesse, Mary Kristen; Mei-Dan, Omer; Strickland, Colin; Petersen, Brian

2015-11-01

This study has three aims: (1) validate a new radiographic measure of acetabular version, the transverse axis distance (TAD) by showing equivalent TAD accuracy in predicting CT equatorial acetabular version when compared to a previously validated, but more cumbersome, radiographic measure, the p/a ratio; (2) establish predictive equations of CT acetabular version from TAD; (3) calculate a sensitive and specific cut point for predicting excessive CT acetabular anteversion using TAD. A 14-month retrospective review was performed of patients who had undergone a dedicated MSK CT pelvis study and who also had a technically adequate AP pelvis radiograph. Two trained observers measured the radiographic p/a ratio, TAD, and CT acetabular equatorial version for 110 hips on a PACS workstation. Mixed model analysis was used to find prediction equations, and ROC analysis was used to evaluate the diagnostic accuracy of p/a ratio and TAD. CT equatorial acetabular version can accurately be predicted from either p/a ratio (p < 0.001) or TAD (p < 0.001). The diagnostic accuracies of p/a ratio and TAD are comparable (p =0.46). Patients whose TAD is higher than 17 mm may have excessive acetabular anteversion. For that cutpoint, the sensitivity of TAD is 0.73, with specificity of 0.82. TAD is an accurate radiographic predictor of CT acetabular anteversion and provides an easy-to-use and intuitive point-of-care assessment of acetabular version in patients with hip pain.

Wear versus Thickness and Other Features of 5-Mrad Crosslinked UHMWPE Acetabular Liners

PubMed Central

Shen, Fu-Wen; Lu, Zhen

2010-01-01

Background The low wear rates of crosslinked polyethylenes provide the potential to use larger diameters to resist dislocation. However, this requires the use of thinner liners in the acetabular component, with concern that higher contact stresses will increase wear, offsetting the benefits of the crosslinking. Questions/purposes We asked the following questions: Is the wear of conventional and crosslinked polyethylene liners affected by ball diameter, rigidity of backing, and liner thickness? Are the stresses in the liner affected by thickness? Methods Wear rates were measured in a hip simulator and stresses were calculated using finite element modeling. Results Without crosslinking, the wear rate was 4% to 10% greater with a 36-mm diameter than a 28-mm diameter. With crosslinking, wear was 9% lower with a 36-mm diameter without metal backing and 4% greater with metal backing. Reducing the thickness from 6 mm to 3 mm increased the contact stress by 46%, but the wear rate decreased by 19%. Conclusions The reduction in wear with 5 Mrad of crosslinking was not offset by increasing the diameter from 28 mm to 36 mm or by using a liner as thin as 3 mm. Clinical Relevance The results indicate, for a properly positioned 5-Mrad crosslinked acetabular component and within the range of dimensions evaluated, neither wear nor stresses in the polyethylene are limiting factors in the use of larger-diameter, thinner cups to resist dislocation. PMID:20848244

The effect of acetabular cup size on the short-term stability of revision hip arthroplasty: a finite element investigation.

PubMed

Phillips, A T M; Pankaj; Usmani, A S; Howie, C R

2004-01-01

The study uses idealized two-dimensional finite element models to examine the behaviour of the acetabular construct following revision hip arthroplasty, carried out using the Slooff-Ling impaction grafting technique. The behaviour of bone graft was considered in detail, with non-linear elasticity and non-associated plasticity being adopted. Load was applied to the acetabular construct through a femoral head using smooth sliding surfaces. In particular, four models were subjected to two idealized cyclic load cases to investigate the effect of acetabular cup size on the short-term stability of the acetabular construct. The study suggests that benefits may be gained by using the largest practical size of acetabular cup.

[Acetabular Osteolysis in Total Hip Replacement - When to Retain the Cup?].

PubMed

Lutz, B; Faschingbauer, M; Bieger, R; Reichel, H; Kappe, T

2016-08-01

Periacetabular osteolysis is a frequent long-term complication of cementless total hip arthroplasty. The decision whether to retain or to revise a cup in the presence of osteolysis remains a challenge. The options are regular clinical and radiological check-ups, isolated liner exchange with and without bone grafting, and complete cup revision. Thorough preoperative diagnostics, including a medical history, examination and imaging, are mandatory for correct decision making. In most patients, computed tomography is useful to assess periacetabular osteolysis. If the cup is well-fixed and positioned in an asymptomatic patient without progressive osteolysis and no implant defect or higher grade polyethylene wear and no signs of infection, continuous clinical and radiological monitoring is preferred. If imaging reveals cup loosening, malposition, osteolysis localised in a weight-bearing area, imminent or present periprosthetic fractures, rapid progressive osteolysis, implant defects or massive inlay wear, surgical treatment may be preferred. Cup revision is usually performed in such patients. If the cup is well-positioned and well-fixed in the X-ray, the procedure has to be discussed with the patient individually. Apart from patient-specific risk factors, the risk of further progression has to be assessed. Isolated liner exchange can be performed if the patient is asymptomatic and the cup proves to be stable intraoperatively. It is still unclear whether filling osteolyses through screw holes or osseous windows is of long-term benefit. Georg Thieme Verlag KG Stuttgart · New York.

Total Hip Arthroplasty in Haemophilic Patients with Modern Cementless Implants.

PubMed

Carulli, Christian; Felici, Irene; Martini, Caterina; Civinini, Roberto; Linari, Silvia; Castaman, Giancarlo; Innocenti, Massimo

2015-10-01

Hip arthropathy due to recurrent haemarthrosis in patients with haemophilia can be disabling. When severe degeneration occurs, total hip arthroplasty is indicated. Reported outcomes are variable and out of date. The aim of this study is to evaluate the survivorship of Total Hip Arthroplasty performed in a patient population with modern cementless implants. Twenty-three haemophilic patients were treated and followed by a multidisciplinary team dedicated to haemophilia. The mean age was 40.6 years. No failures or complications were recorded at a mean follow-up of 8.1 years (range: 3.1-13.7). A multidisciplinary team and the use of modern cementless implants may represent the keys to achieve good outcomes, fewer complications, and better survivorship in the approach to these difficult cases. Copyright © 2015 Elsevier Inc. All rights reserved.

A novel method to assess primary stability of press-fit acetabular cups.

PubMed

Crosnier, Emilie A; Keogh, Patrick S; Miles, Anthony W

2014-11-01

Initial stability is an essential prerequisite to achieve osseointegration of press-fit acetabular cups in total hip replacements. Most in vitro methods that assess cup stability do not reproduce physiological loading conditions and use simplified acetabular models with a spherical cavity. The aim of this study was to investigate the effect of bone density and acetabular geometry on cup stability using a novel method for measuring acetabular cup micromotion. A press-fit cup was inserted into Sawbones(®) foam blocks having different densities to simulate normal and osteoporotic bone variations and different acetabular geometries. The stability of the cup was assessed in two ways: (a) measurement of micromotion of the cup in 6 degrees of freedom under physiological loading and (b) uniaxial push-out tests. The results indicate that changes in bone substrate density and acetabular geometry affect the stability of press-fit acetabular cups. They also suggest that cups implanted into weaker, for example, osteoporotic, bone are subjected to higher levels of micromotion and are therefore more prone to loosening. The decrease in stability of the cup in the physiological model suggests that using simplified spherical cavities to model the acetabulum over-estimates the initial stability of press-fit cups. This novel testing method should provide the basis for a more representative protocol for future pre-clinical evaluation of new acetabular cup designs. © IMechE 2014.

Acetabular fractures in the elderly treated with a primary Burch-Schneider reinforcement ring, autologous bone graft, and a total hip arthroplasty: a prospective study with a 4-year follow-up.

PubMed

Enocson, Anders; Blomfeldt, Richard

2014-06-01

To investigate the clinical and radiologic outcomes in elderly patients suffering from an acetabular fracture operated with an acute primary acetabular reinforcement ring, autologous bone graft, and a total hip arthroplasty (THA). Prospective cohort study. Tertiary care university hospital. Fifteen elderly patients (7 women) with a mean age of 76 years and a displaced acetabular fracture after a low-energy trauma were included. The fractures involved the anterior column, but no patients with associated both column fractures were included. All the patients were able to walk independently before the fracture occurred. Primary operation with a Burch-Schneider reinforcement ring, autologous bone graft, and a THA. The patients were reviewed at 4, 12, 24, and 48 months after the fracture occurred. The outcome assessments included complications, reoperations, activity of daily living function, functional scores (Harris hip score and short musculoskeletal function assessment), health-related quality of life [EuroQol (EQ-5D) index score], and radiologic evaluation. There were no prosthetic dislocations, periprosthetic fractures, deep infections, or other adverse events. There were no radiologic signs of loosening of the reinforcement ring or the prosthesis components at any of the follow up sessions, and the autologous bone graft was well incorporated in all the patients at the final follow-up. At 48 months, the mean Harris hip score was 88, the mean short musculoskeletal function assessment dysfunction score was 30, the bother score was 25, and the mean EQ-5D index score was 0.65. All the patients were able to walk independently at the final follow-up. Treatment of displaced anterior column, anterior column posterior hemitransverse and transverse acetabular fractures in elderly patients using a primary reinforcement ring, autologous bone graft, and a THA seems to be a safe option with good functional and radiologic outcomes. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Treatment of acetabular fractures in older patients-introduction of a new implant for primary total hip arthroplasty.

PubMed

Resch, H; Krappinger, D; Moroder, P; Auffarth, A; Blauth, M; Becker, J

2017-04-01

Fractures of the acetabulum in younger patients are commonly treated by open reduction and internal fixation. For elderly patients, stable primary total hip arthroplasty with the advantage of immediate postoperative mobilization might be the adequate treatment. For this purpose, a sufficiently stable fixation of the acetabular component is required. Between August 2009 and 2014, 30 cases were reported in which all patients underwent total hip arthroplasty additionally to a customized implant designed as an antiprotrusion cage. Inclusion criteria were an acetabular fracture with or without a previous hemiarthroplasty, age above 65 years, and pre-injury mobility dependent on a walking frame at the most. The median age was 79.9 years (65-92), and of 30 fractures, 25 were primary acetabular fractures (83%), four periprosthetic acetabular fractures (14%), and one non-union after a failed ORIF (3%). The average time from injury to surgery was 9.4 days (3-23) and 295 days for the non-union case. Mean time of surgery was 154.4 min (range 100 to 303). In 21 cases (70%), mobilization with full weight bearing was possible within the first 10 days. Six patients died before the follow-up examination 3 and 6 months after surgery, while 24 patients underwent radiologic examination showing consolidated fractures in bi-plane radiographs. In 9 patients, additional CT scan was performed which confirmed the radiographical results. 13 had regained their pre-injury level of mobility including the non-union case. Only one patient did not regain independent mobility. Four complications were recognized with necessary surgical revision (one prosthetic head dislocation, one pelvic cement leakage, one femoral shaft fracture, and one infected hematoma). The presented cage provides the possibility of early mobilization with full weight bearing which represents a valuable addition to the treatment spectrum in this challenging patient group.

Effect of acetabular cup abduction angle on wear of ultrahigh-molecular-weight polyethylene in hip simulator testing.

PubMed

Korduba, Laryssa A; Essner, Aaron; Pivec, Robert; Lancin, Perry; Mont, Michael A; Wang, Aiguo; Delanois, Ronald E

2014-10-01

The effect of acetabular component positioning on the wear rates of metal-on-polyethylene articulations has not been extensively studied. Placement of acetabular cups at abduction angles of more than 40° has been noted as a possible reason for early failure caused by increased wear. We conducted a study to evaluate the effects of different acetabular cup abduction angles on polyethylene wear rate, wear area, contact pressure, and contact area. Our in vitro study used a hip joint simulator and finite element analysis to assess the effects of cup orientation at 4 angles (0°, 40°, 50°, 70°) on wear and contact properties. Polyethylene bearings with 28-mm cobalt-chrome femoral heads were cycled in an environment mimicking in vivo joint fluid to determine the volumetric wear rate after 10 million cycles. Contact pressure and contact area for each cup abduction angle were assessed using finite element analysis. Results were correlated with cup abduction angles to determine if there were any differences among the 4 groups. The inverse relationship between volumetric wear rate and acetabular cup inclination angle demonstrated less wear with steeper cup angles. The largest abduction angle (70°) had the lowest contact area, largest contact pressure, and smallest head coverage. Conversely, the smallest abduction angle (0°) had the most wear and most head coverage. Polyethylene wear after total hip arthroplasty is a major cause of osteolysis and aseptic loosening, which may lead to premature implant failure. Several studies have found that high wear rates for cups oriented at steep angles contributed to their failure. Our data demonstrated that larger cup abduction angles were associated with lower, not higher, wear. However, this potentially "protective" effect is likely counteracted by other complications of steep cup angles, including impingement, instability, and edge loading. These factors may be more relevant in explaining why implants fail at a higher rate if cups are oriented at more than 40° of abduction.

How Reliable is the Acetabular Cup Position Assessment from Routine Radiographs?

PubMed Central

Carvajal Alba, Jaime A.; Vincent, Heather K.; Sodhi, Jagdeep S.; Latta, Loren L.; Parvataneni, Hari K.

2017-01-01

Abstract Background: Cup position is crucial for optimal outcomes in total hip arthroplasty. Radiographic assessment of component position is routinely performed in the early postoperative period. Aims: The aims of this study were to determine in a controlled environment if routine radiographic methods accurately and reliably assess the acetabular cup position and to assess if there is a statistical difference related to the rater’s level of training. Methods: A pelvic model was mounted in a spatial frame. An acetabular cup was fixed in different degrees of version and inclination. Standardized radiographs were obtained. Ten observers including five fellowship-trained orthopaedic surgeons and five orthopaedic residents performed a blind assessment of cup position. Inclination was assessed from anteroposterior radiographs of the pelvis and version from cross-table lateral radiographs of the hip. Results: The radiographic methods used showed to be imprecise specially when the cup was positioned at the extremes of version and inclination. An excellent inter-observer reliability (Intra-class coefficient > 0,9) was evidenced. There were no differences related to the level of training of the raters. Conclusions: These widely used radiographic methods should be interpreted cautiously and computed tomography should be utilized in cases when further intervention is contemplated. PMID:28852355

[Early aseptic loosening of the CF 30 femoral stem].

PubMed

Kovanda, M; Havlícek, V; Hudec, J

2007-02-01

The CF 30 stem in combination with a cementless acetabulum was used at the First Department of Orthopedic Surgery in Brno in the years 1994 to 1995. From the second year following implantation, aseptic stem loosening was recorded. In order to find explanation of this early loosening, the authors, in cooperation with the Institute of Solid Mechanics, Mechatronics and Biomechanics, carried out the stress-strain analysis in a model system. Eighty patients (31 men and 49 women) received a cemented CF30 femoral component in 1994. Of them, 16 patients underwent revision arthroplasty, three died of causes unrelated to the surgery, and four were lost to follow-up. The final clinical and radiographic check-up was carried out in 2001. The results of a comprehensive examination were available in 57 patients with a CF30 stem. The patients were evaluated on the basis of the Harris hip score and anteroposterior radiographs of the hip. X-ray films obtained immediately after surgery and those taken at regular intervals during follow-up were compared. The following characteristics were noted: translucent lines in individual zones along the stem at the cement-bone interface; osteolysis, i. e., non-linear translucent areas, at least 5 mm long, at the cement-bone interface; and subsidence of the femoral component, i. e., migration of the stem distal to the tip of the greater trochanter. The CF 30 stem survival curve showed that aseptic stem loosening occurred from post-implantation year 2, and increased during the following years. At 6 years and 6 months, a total of 16 patients underwent revision surgery, involving reimplantation in 14 and implant removal in 2 patients. Potential causes of aseptic loosening: Polyethylene wear.However, no acetabular loosening was found in this group, although acetabular components are reported to become loose more often than femoral components. By comparison of the stem survival curves for Poldi and CF 30 stems it appeared that, at 6 years and 6 months, the Poldi stem survival curve showed better results. Matt surface finish of the stem. However, the link between the CF 30 stem and cement was so strong that, in all 16 revised hips, the stem was removed together with nearly a complete cement mantle. The authors therefore dismiss this as a cause. Also, in the remaining cases of CF 30 aseptic loosening, which had not been revised, radiographic evidence suggested loosening between bone and cement. The authors did not find any movement of the CF stem in its cement mantle. The stem always fitted in with the cement mantle. Erroneous surgical technique or cementing was unlikely. The procedures were performed by experienced orthopedic surgeons who used the second-generation cementing technique. In patients with a Poldi stem, the first-generation cementing method was used and the proportion of aseptic loosening at 6 years of follow-up was only 4 %. In contrast, loosening in patients with the CF 30 stem was 20 % at 6 years and 6 months postoperatively. Shape of the CF 30 stem with the intention to find a relationship between stem shape and its early aseptic loosening, the authors started cooperation with the Institute of Solid Mechanics, Mechatronics and Biomechanics at the Faculty of Mechanical Engineering, Brno University of Technology. Using the method of finite elements, they carried out the stressstrain analysis in a model system. Stress at the cement-bone interface in the CF 30 stem was higher than in the Poldi stem, and this difference was statistically significant. The authors believe that the more frequent loosening found in patients with the CF 30 stem can be accounted for by its shape. The survival curve for the CF 30 femoral stem did not show good results, and therefore this stem is not recommended for implantation. The authors suggest that a more frequent early aseptic loosening of CF 30 stems may have been caused by its unsuitable shape.

Cementless Oxford medial unicompartimental knee replacement: an independent series with a 5-year-follow-up.

PubMed

Panzram, Benjamin; Bertlich, Ines; Reiner, Tobias; Walker, Tilman; Hagmann, Sébastien; Gotterbarm, Tobias

2017-07-01

Cemented unicompartmental knee replacement (UKR) has proven excellent long-term survival rates and functional scores in Price et al. (Clin Orthop Relat Res 435:171-180, 2005), Price and Svard (Clin Orthop Relat Res 469(1):174-179, 2011) and Murray et al. (Bone Joint Surg Br 80(6):983-989, 1998). The main causes for revision, aseptic loosening and pain of unknown origin might be addressed by cementless UKR in Liddle et al. (Bone Joint J 95-B(2):181-187, 2013), Pandit et al. (J Bone Joint Surg Am 95(15):1365-1372, 2013), National Joint Registry for England, Wales and Northern Ireland: 10th Annual Report 2013 ( http://www.njrcentre.org.uk/njrcentre/Portals/0/Documents/England/Reports/10th_annual_report/NJR%2010th%20Annual%20Report%202013%20B.pdf , 2013), Swedish Knee Arthroplasty Register: Annual Report 2013 ( http://www.myknee.se/pdf/SKAR2013_Eng.pdf , 2013). This single-centre retrospective cohort study reports the 5-year follow-up results of our first 30 consecutively implanted cementless Oxford UKR (OUKR). Clinical outcome was measured using the OKS, AKSS, range of movement and level of pain (visual analogue scale). The results were compared to cemented OUKR in a matched-pair analysis. Implant survival was 89.7%. One revision each was performed due to tibial fracture, progression of osteoarthritis (OA) and inlay dislocation. The 5-year survival rate of the cementless group was 89.7% and of the cemented group 94.1%. Both groups showed excellent postoperative clinical scores. Cementless fixation shows good survival rates and clinical outcome compared to cemented fixation.

Acetabular inclination and anteversion in infants using 3D MR imaging.

PubMed

Falliner, A; Muhle, C; Brossmann, J

2002-03-01

To establish if 3D MR imaging could be used for measurements of acetabular inclination and anteversion in infants specimens. 3D MR data of 3 pelvic preparations of 6-week- to 10-month-old infant specimens was gathered. MR imaging in transaxial and frontal planes was carried out to measure the acetabular inclination and anteversion: a method to determine the MR planes for measurements is described. It was oriented on anatomical landmarks of the pelvis and therefore allowed adjustment of the frontal and transaxial planes, independent of the pelvis position. The mean acetabular inclination angle was 48 degrees, and the mean acetabular anteversion was 23 degrees. Because of the low number of cases the results can only be assessed as a tendency, but MR imaging seems to be suitable for measurements of acetabular inclination and anteversion.

Is the rate of revision of 36 mm metal-on-metal total hip arthroplasties with Pinnacle acetabular components related to the year of the initial operation? an interrupted time-series analysis using data from the National Joint Registry for England and Wales.

PubMed

Matharu, G S; Hunt, L P; Murray, D W; Howard, P; Pandit, H G; Blom, A W; Bolland, B; Judge, A

2018-01-01

The aim of this study was to determine whether the rates of revision for metal-on-metal (MoM) total hip arthroplasties (THAs) with Pinnacle components varied according to the year of the initial operation, and compare these with the rates of revision for other designs of MoM THA. Data from the National Joint Registry for England and Wales included 36 mm MoM THAs with Pinnacle acetabular components which were undertaken between 2003 and 2012 with follow-up for at least five years (n = 10 776) and a control group of other MoM THAs (n = 13 817). The effect of the year of the primary operation on all-cause rates of revision was assessed using Cox regression and interrupted time-series analysis. For MoM THAs involving Pinnacle components, those undertaken between 2007 and 2012 had higher rates of revision compared with those undertaken between 2004 and 2006 (hazard ratio (HR) 2.01; 95% confidence interval (CI) 1.57 to 2.57; p < 0.001). For THAs undertaken during and after 2007, the number of revisions per 1000 implant-years at risk significantly increased by 5.20 (95% CI 0.52 to 9.89; p = 0.033) compared with those undertaken before this time. In the control group, THAs undertaken between 2007 and 2012 also had higher rates of revision (HR 1.77; 95% CI 1.49 to 2.10; p < 0.001), with revisions per 1000 implant-years for those undertaken during and after 2007 significantly increasing by 6.13 (95% CI 1.42 to 10.83; p = 0.016). The five-year revision rates were significantly increased for all primary MoM THAs undertaken from 2007 onwards. Contrary to recent reports, this finding was not specific to those involving Pinnacle acetabular components and may be explained by increased surveillance and recent lowering of the threshold for revision. Cite this article: Bone Joint J 2018;100-B:33-41. ©2018 The British Editorial Society of Bone & Joint Surgery.

Periacetabular Osteotomy Provides Higher Survivorship Than Rim Trimming for Acetabular Retroversion.

PubMed

Zurmühle, Corinne A; Anwander, Helen; Albers, Christoph E; Hanke, Markus S; Steppacher, Simon D; Siebenrock, Klaus A; Tannast, Moritz

2017-04-01

Acetabular retroversion can cause impaction-type femoroacetabular impingement leading to hip pain and osteoarthritis. It can be treated by anteverting periacetabular osteotomy (PAO) or acetabular rim trimming with refixation of the labrum. There is increasing evidence that acetabular retroversion is a rotational abnormality of the entire hemipelvis and not a focal overgrowth of the anterior acetabular wall, which favors an anteverting PAO. However, it is unknown if this larger procedure would be beneficial in terms of survivorship and Merle d'Aubigné scores in a midterm followup compared with rim trimming. We asked if anteverting PAO results in increased survivorship of the hip compared with rim trimming through a surgical hip dislocation in patients with symptomatic acetabular retroversion. We performed a retrospective, comparative study evaluating the midterm survivorship of two matched patient groups with symptomatic acetabular retroversion undergoing either anteverting PAO or acetabular rim trimming through a surgical hip dislocation. Acetabular retroversion was defined by a concomitantly present positive crossover, posterior wall, and ischial spine sign. A total of 279 hips underwent a surgical intervention for acetabular retroversion at our center between 1997 and 2012 (166 periacetabular osteotomies, 113 rim trimmings through surgical hip dislocation). A total of 99 patients (60%) were excluded from the PAO group and 56 patients (50%) from the rim trimming group because they had any of several prespecified conditions (eg, dysplasia or pediatric conditions 61 [37%] for the PAO group and two [2%] for the rim trimming group), matching (10 [6%]/10 [9%] hips), deficient records (10 [6%]/13 [12%] hips), or the patient declined or was lost to followup (18 [11%]/31 [27%] hips). This left 67 hips (57 patients) that underwent anteverting PAO and 57 hips (52 patients) that had acetabular rim trimming. The two groups did not differ in terms of age, sex, body mass index, preoperative ROM, preoperative Merle d'Aubigné-Postel score, radiographic morphology of the acetabulum (except total and anterior acetabular coverage), alpha angle, Tönnis grade of osteoarthritis, and labral and chondral lesions on the preoperative MRI. During the period in question, we generally performed PAO from 1997 to 2003. With the availability of surgical hip dislocation and labral refixation, we generally performed rim trimming from 2004 to 2010. With growing knowledge of the underlying pathomorphology, anteverting PAOs became more common again around 2007 to 2008. A minimum followup of 2 years was required for this study. Failures were included at any time. The median followup for the anteverting PAO group was 9.5 years (range, 2-17.4 years) and 6.8 years (range, 2.2-10.5 years) for the rim trimming group (p < 0.001). Kaplan-Meier survivorship analysis was performed using the following endpoints at 5 and 10 years: THA, radiographic progression of osteoarthritis by one Tönnis grade, and/or Merle d'Aubigné-Postel score < 15 points. Although the 5-year survivorship of the two groups was not different with the numbers available (86% [95% confidence interval {CI}, 76%-94%] for anteverting PAO versus 86% [95% CI, 76%-96%] for acetabular rim trimming), we found increased survivorship at 10 years in hips undergoing anteverting PAO for acetabular retroversion (79% [95% CI, 68%-90%]) compared with acetabular rim trimming (23% [95% CI, 6%-40%]) at 10 years (p < 0.001). The drop in the survivorship curve for the acetabular rim trimming through surgical hip dislocation group started at Year 6. The main reason for failure was a decreased Merle d'Aubigné score. Anteverting PAO may be the more appropriate treatment for hips with substantial acetabular retroversion. This may be the result of reduction of an already smaller lunate surface of hips with acetabular retroversion through rim trimming. However, rim trimming may still benefit hips with acetabular retroversion in which only one or two of the three signs are positive. Future randomized studies should compare these treatments. Level III, therapeutic study.

High proximal migration in cemented acetabular revisions operated with bone impaction grafting; 47 revision cups followed with RSA for 17 years.

PubMed

Mohaddes, Maziar; Herberts, Peter; Malchau, Henrik; Johanson, Per-Erik; Kärrholm, Johan

2017-05-12

Bone impaction grafting is a biologically and mechanically appealing option in acetabular revision surgery, allowing restitution of the bone stock and restoration of the biomechanics. We analysed differences in proximal migration of the revision acetabular components when bone impaction grafting is used together with a cemented or an uncemented cup. 43 patients (47 hips), revised due to acetabular loosening and judged to have less than 50% host bone-implant contact were included. The hips were randomised to either an uncemented (n = 20) or a cemented (n = 27) revision cup. Radiostereometry and radiography was performed postoperatively, at 3 and 6 months, 1, 2, 3, 5, 7, 10 and 13 and 17 years postoperatively. Clinical follow-up was performed at 1, 2 and 5 years postoperatively and thereafter at the same interval as in the radiographic follow-up. There were no differences in the base line demographic data between the 2 groups. At the last follow-up (17 years) 14 hips (10 cemented, 4 uncemented) had been re-revised due to loosening. 3 additional cups (1 uncemented and 2 cemented) were radiographically loose. There was a higher early proximal migration in the cemented cups. Cups operated on with cement showed a higher early migration measured with RSA and also a higher number of late revisions. The reason for this is not known, but factors such as inclusion of cases with severe bone defects, use of smaller bone chips and issues related to the impaction technique might have had various degrees of influence.

Posterosuperior Placement of a Standard-Sized Cup at the True Acetabulum in Acetabular Reconstruction of Developmental Dysplasia of the Hip With High Dislocation.

PubMed

Xu, Jiawei; Xu, Chen; Mao, Yuanqing; Zhang, Jincheng; Li, Huiwu; Zhu, Zhenan

2016-06-01

We sought to evaluate posterosuperior placement of the acetabular component at the true acetabulum during acetabular reconstruction in patients with Crowe type-IV developmental dysplasia of the hip. Using pelvic computed tomography and image processing, we developed a two-dimensional mapping technique to demonstrate the distribution of preoperative three-dimensional cup coverage at the true acetabulum, determined the postoperative location of the acetabular cup, and calculated postoperative three-dimensional coverage for 16 Crowe type-IV dysplastic hips in 14 patients with a mean age of 52 years (33-78 years) who underwent total hip arthroplasty. Mean follow-up was 6.3 years (5.5-7.3 years). On preoperative mapping, the maximum three-dimensional coverage using a 44-mm cup was 87.31% (77.36%-98.14%). Mapping enabled the successful replacement of 16 hips using a mean cup size of 44.13 mm (42-46 mm) with posterosuperior placement of the cup. Early weight-bearing and no prosthesis revision or loosening during follow-up were achieved in all patients. The postoperative two-dimensional coverage on anteroposterior radiographs and three-dimensional coverage were 96.15% (89.49%-100%) and 83.42% (71.81%-98.50%), respectively. This technique may improve long-term implant survival in patients with Crowe-IV developmental dysplasia of the hip undergoing total hip arthroplasty by allowing the use of durable bearings, increasing host bone coverage, ensuring initial stability, and restoring the normal hip center. Copyright © 2015 Elsevier Inc. All rights reserved.

Long-term result of cementless femoral stem in avascular necrosis of the hip.

PubMed

Cheung, Kin W; Chiu, Kwok H; Chung, Kwong Y

2015-01-01

Avascular necrosis (AVN) of the hip may have extensive involvement of the proximal femur which may affect boney ingrowth into cementless femoral stems. From 1994 to 2004, 182 total hip arthroplasties (in 144 patients, 117 AVN hips and 65 non-AVN hips) were performed using hydroxyapatite coated femoral stems. All patients were followed up prospectively. Mean age was 51 years and mean follow-up 14.7 years (range 9.7-19.1 years). Four stems were revised because of aseptic loosening, 3 in AVN group and 1 in non-AVN group. The overall mechanical failure rate was 2.2%, the mechanical failure rate in AVN and non-AVN group was 2.6% and 1.5% respectively (p = 1). The 19.1 year survival using revision for aseptic loosening as an endpoint for AVN and non-AVN patients were 97.1% and 96.2% respectively (p = 0.654). Stable boney ingrowth was present in 99.5% hips. This study represents 1 of the largest series reporting the long-term follow-up of the use of cementless femoral stems in treating AVN of the hip. We report excellent long-term survival of cementless total hip arthroplasty used in managing AVN of the hip and is comparable to that seen in non-AVN total hip arthroplasty.

An initial experience with hip resurfacing versus cementless total hip arthroplasty.

PubMed

Arndt, Justin Michael; Wera, Glenn D; Goldberg, Victor M

2013-07-01

Hip resurfacing is an alternative to total hip arthroplasty. We aimed to compare an experienced hip surgeon's initial clinical results of hip resurfacing with a new cementless total hip arthroplasty (THA). The first 55 consecutive hip resurfacing arthroplasties were compared to 100 consecutive cementless THAs using a cylindrical tapered femoral stem. The learning curve between the two procedures was compared utilizing the incidence of reoperation, complications, Harris Hip Scores (HHS), and implant survivorship. The reoperation rate was significantly higher (p = 0.019) for hip resurfacing (14.5%) versus THA (4%). The overall complication rate between the two groups was not significantly different (p = 0.398). Preoperative HHS were similar between the two groups (p = 0.2). The final mean HHS was similar in both the resurfacing and THA groups (96 vs. 98.3, respectively, p < 0.65). Kaplan-Meier survival analysis with an endpoint of reoperation suggests complications occurred earlier in the resurfacing group versus the THA group (log-rank test, p = 0.007). In comparison to our initial experience with a cementless THA stem, operative complications occur earlier and more often after hip resurfacing during the learning period. The clinical outcomes in both groups however are similar at 5 year follow-up.

Correlation between thigh pain and radiological findings with a proximally porous-coated stem.

PubMed

Kinov, Plamen; Radl, Roman; Zacherl, Maximilian; Leithner, Andreas; Windhager, Reinhard

2007-10-01

Thigh pain has been consistently reported with cementless hip arthroplasty. The correlation between thigh pain and radiological findings and the clinical significance of thigh pain have not been studied in any detail. We carried out a retrospective study to analyse the performance of a proximally porous-coated cementless femoral component. Ninety-eight total hip arthroplasties were followed up clinically and radiologically for an average of 33 months (range: 12 to 64) after operation. The clinical results were good or excellent in 85 cases (87%). Thirteen patients (13%) reported thigh pain at latest follow-up. Subsidence of the stem was recorded in 10 cases, cortical thickening occurred in 14 hips (14%), and 17 hips (17%) presented proximal osteopenia. Proximally, radiolucent lines were observed in 11 cases. Thigh pain correlated with radiolucent lines, femoral thickening, fibrous fixation and stem migration. Bone remodelling was noted to continue even five years after implantation. Our observations demonstrated bone ingrowth in the majority of the cases and a low incidence of thigh pain. The correlation between radiological changes and thigh pain suggests implant micromotion and migration in some hips. Patients with thigh pain, changes in the proximal femur and progressive subsidence need further clinical and radiological follow-up.

Sacroiliac joint dysfunction as a reason for the development of acetabular retroversion: a new theory.

PubMed

Cibulka, Michael T

2014-05-01

Acetabular retroversion has been recently implicated as an important factor in the development of femoral acetabular impingement and hip osteoarthritis. The proper function of the hip joint requires that the anatomic features of the acetabulum and femoral head complement one another. In acetabular retroversion, the alignment of the acetabulum is altered where it opens in a posterolaterally instead of anterior direction. Changes in acetabular orientation can occur with alterations in pelvic tilt (anterior/posterior), and pelvic rotation (left/right). An overlooked problem that alters pelvic tilt and rotation, often seen by physical therapists, is sacroiliac joint dysfunction. A unique feature that develops in patients with sacroiliac joint dysfunction (SIJD) is asymmetry between the left and right innominate bones that can alter pelvic tilt and rotation. This article puts forth a theory suggesting that acetabular retroversion may be produced by sacroiliac joint dysfunction.

Computer assisted surgery in preoperative planning of acetabular fracture surgery: state of the art.

PubMed

Boudissa, Mehdi; Courvoisier, Aurélien; Chabanas, Matthieu; Tonetti, Jérôme

2018-01-01

The development of imaging modalities and computer technology provides a new approach in acetabular surgery. Areas covered: This review describes the role of computer-assisted surgery (CAS) in understanding of the fracture patterns, in the virtual preoperative planning of the surgery and in the use of custom-made plates in acetabular fractures with or without 3D printing technologies. A Pubmed internet research of the English literature of the last 20 years was carried out about studies concerning computer-assisted surgery in acetabular fractures. The several steps for CAS in acetabular fracture surgery are presented and commented by the main author regarding to his personal experience. Expert commentary: Computer-assisted surgery in acetabular fractures is still initial experiences with promising results. Patient-specific biomechanical models considering soft tissues should be developed to allow a more realistic planning.

Acetabular overcoverage in the horizontal plane: an underdiagnosed trigger of early hip arthritis. A CT scan study in young adults.

PubMed

Valera, Màrius; Ibáñez, Natalia; Sancho, Rogelio; Llauger, Jaume; Gich, Ignasi

2018-01-01

Acetabular overcoverage promotes hip osteoarthritis causing a pincer-type femoroacetabular impingement. Acetabular coverage in the horizontal plane is usually poorly defined in imaging studies and may be misdiagnosed. The goal of this study was to analyze the role of acetabular overcoverage measured in the frontal plane and in the horizontal plane by CT scan and to determine its relationship with other anatomic features in the onset of hip arthritis in young adults. We compared prospectively CT scans from two groups of adults of 55 years or younger: the patient group (n = 30) consisted of subjects with diagnosis of early hip arthritis (Tönnis Grade I or II) and the control group (n = 31) consisted of subjects with healthy hips. Two independent observers analyzed centre edge angle (CEA), acetabular anteversion angle (AAA), anterior sector acetabular angle (AASA), posterior sector acetabular angle (PASA), horizontal acetabular sector angle (HASA), femoral anteversion angle (FAVA), alpha angle (AA), and Mckibbin Instability Index (MI). Angles measuring the acetabular coverage on the horizontal plane (AASA, PASA and, HASA) were significantly higher in the patient group (p < 0.001, p = 0.03 and p < 0.001, respectively). Pearson's correlation coefficient showed a positive correlation between CEA and HASA in patients (r = 0.628) and in controls (r = 0.660). However, a high CEA (> 35º) was strongly associated with a high HASA (> 160º) in patients (p = 0.024) but not in controls (p = 0.21), suggesting that pincer should be simultaneously present in the horizontal and frontal plane to trigger hip degeneration. No significant association was detected between a high alpha angle (> 60º) and a high CEA (> 35º suggesting that a mixed pincer-cam aetiology was not prevalent in our series. Multivariate regression analysis showed the most significant predictors of degenerative joint disease were HASA (p = 0.008), AA (p = 0.048) and ASAA (p = 0.004). Acetabular overcoverage in the horizontal plane plays an important role in the onset of early hip arthritis. Considering that this condition is usually underdiagnosed, we suggest the anterior sector acetabular angle, the posterior sector acetabular angle, and the horizontal acetabular sector angles be routinely included in decision-making algorithms in hip conservative surgery to better define hips-at-risk of developing early hip osteoarthritis.

[Application of three-dimensional printing personalized acetabular wing-plate in treatment of complex acetabular fractures via lateral-rectus approach].

PubMed

Mai, J G; Gu, C; Lin, X Z; Li, T; Huang, W Q; Wang, H; Tan, X Y; Lin, H; Wang, Y M; Yang, Y Q; Jin, D D; Fan, S C

2017-03-01

Objective: To investigate reduction and fixation of complex acetabular fractures using three-dimensional (3D) printing technique and personalized acetabular wing-plate via lateral-rectus approach. Methods: From March to July 2016, 8 patients with complex acetabular fractures were surgically managed through 3D printing personalized acetabular wing-plate via lateral-rectus approach at Department of Orthopedics, the Third Affiliated Hospital of Southern Medical University. There were 4 male patients and 4 female patients, with an average age of 57 years (ranging from 31 to 76 years). According to Letournel-Judet classification, there were 2 anterior+ posterior hemitransverse fractures and 6 both-column fractures, without posterior wall fracture or contralateral pelvic fracture. The CT data files of acetabular fracture were imported into the computer and 3D printing technique was used to print the fractures models after reduction by digital orthopedic technique. The acetabular wing-plate was designed and printed with titanium. All fractures were treated via the lateral-rectus approach in a horizontal position after general anesthesia. The anterior column and the quadrilateral surface fractures were fixed by 3D printing personalized acetabular wing-plate, and the posterior column fractures were reduction and fixed by antegrade lag screws under direct vision. Results: All the 8 cases underwent the operation successfully. Postoperative X-ray and CT examination showed excellent or good reduction of anterior and posterior column, without any operation complications. Only 1 case with 75 years old was found screw loosening in the pubic bone with osteoporosis after 1 month's follow-up, who didn't accept any treatment because the patient didn't feel discomfort. According to the Matta radiological evaluation, the reduction of the acetabular fracture was rated as excellent in 3 cases, good in 4 cases and fair in 1 case. All patients were followed up for 3 to 6 months and all patients had achieved bone union. According to the modified Merle D'Aubigné and Postel scoring system, 5 cases were excellent, 2 cases were good, 1 case was fair. Conclusions: Surgical management of complex acetabular fracture via lateral-rectus approach combine with 3D printing personalized acetabular wing-plate can effectively improve reduction quality and fixation effect. It will be truly accurate, personalized and minimally invasive.

Hip morphologic measurements in an Egyptian population.

PubMed

Aly, Tarek A

2011-04-11

The study of acetabular morphology has shown that there are geographic differences in the morphology and prevalence of acetabular dysplasia among different ethnic groups. However, few data exist on the shape of the acetabulum in various populations around the world. In this study, we examined samples of pelvic radiographs from Egyptian adults. Acetabular dysplasia in adults is characterized by a shallow and relatively vertical acetabulum.The aim of this study was to examine acetabular morphology to determine the prevalence of hip dysplasia in adult Egyptians. This included 244 adults, 134 men and 110 women between 18 and 60 years, who were used to measure center edge angle, acetabular Sharp angle, acetabular head index on anteroposterior radiographic views of the hip joints, and vertical center anterior margin angle on false profile views. The radiographs were taken of patients with no hip complaints at Tanta University Hospital.The results were statistically studied according to the age, height, and weight of patients. The prevalence of acetabular dysplasia was 2.25% for Egyptian men and 3.6% for women with respect to center edge angles, vertical center anterior margin angle, and acetabular head index.We concluded that gender variations in the morphology of the acetabulum and sex influences geometrical measurements of the acetabulum. Egyptian women were more dysplastic than men using the 4 parameters of hip measurements. There are also racial variations in hip morphology. Copyright 2011, SLACK Incorporated.

Decreased Lumbar Lordosis and Deficient Acetabular Coverage Are Risk Factors for Subchondral Insufficiency Fracture.

PubMed

Jo, Woo Lam; Lee, Woo Suk; Chae, Dong Sik; Yang, Ick Hwan; Lee, Kyoung Min; Koo, Kyung Hoi

2016-10-01

Subchondral insufficiency fracture (SIF) of the femoral head occurs in the elderly and recipients of organ transplantation. Osteoporosis and deficient lateral coverage of the acetabulum are known risk factors for SIF. There has been no study about relation between spinopelvic alignment and anterior acetabular coverage with SIF. We therefore asked whether a decrease of lumbar lordosis and a deficiency in the anterior acetabular coverage are risk factors. We investigated 37 patients with SIF. There were 33 women and 4 men, and their mean age was 71.5 years (59-85 years). These 37 patients were matched with 37 controls for gender, age, height, weight, body mass index and bone mineral density. We compared the lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope, acetabular index, acetabular roof angle, acetabular head index, anterior center-edge angle and lateral center-edge angle. Lumbar lordosis, pelvic tilt, sacral slope, lateral center edge angle, anterior center edge angle, acetabular index and acetabular head index were significantly different between SIF group and control group. Lumbar lordosis (OR = 1.11), lateral center edge angle (OR = 1.30) and anterior center edge angle (OR = 1.27) had significant associations in multivariate analysis. Decreased lumbar lordosis and deficient anterior coverage of the acetabulum are risk factors for SIF as well as decreased lateral coverage of the acetabulum.

Could larger diameter of 4th generation ceramic bearing decrease the rate of dislocation after THA?

PubMed

Lee, Young-Kyun; Ha, Yong-Chan; Jo, Woo-Lam; Kim, Tae-Young; Jung, Woon-Hwa; Koo, Kyung-Hoi

2016-05-01

Fourth generation (Delta) ceramic bearing was developed to reduce dislocation after total hip arthroplasty (THA) by increasing the head diameter. We tested a hypothesis that 32/36 mm Delta ceramic bearing decreases the dislocation rate. We also evaluated ceramic-related complications and early outcome of this thin liner-on-large head ceramic bearing. We performed a prospective study on patients who underwent THA with use of 32/36 mm Delta ceramic bearing. The dislocation rate was compared with the historical dislocation rate of third generation 28 mm ceramic bearing. We also evaluated ceramic fracture, squeak, short-term results and survival. Follow-up period was minimum 2 years. Between April 2010 and February 2012, we enrolled 250 consecutive patients (278 hips). All patients received cementless prostheses. Four patients (4 hips) who received metal shells ≤ 46 mm and 28 mm heads were excluded. Three patients died and 2 patients were lost within 2 years. The remaining 241 patients (269 hips) were followed for 24-46 months. There were 142 men (161 hips) and 99 women (108 hips) with a mean age of 53.7 years (range, 17-75 years) at the index operation. Dislocation occurred in three hips (1.1%). An old age was a risk factor for dislocation. Ceramic fracture and squeaking did not occur in any patient. Mean Harris hip score was 90.3 points at the latest follow-up. All acetabular and femoral components had bone-ingrowth stability. No hip had detectable wear or osteolysis. The survival was 99.3% in the best case scenario and 97.8% in the worst at 48 months. Total hip arthroplasty with use of 32/36 mm Delta ceramic bearing showed lower incidence of hip dislocation compared with 28 mm third generation ceramic bearing. A caution should be paid to prevent a fall in senile patients even though a large head is used. The short-term results of THA with this type of ceramic articulation are encouraging and we did not find any ceramic-related complications. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Cementless Hydroxyapatite Coated Hip Prostheses

PubMed Central

Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda

2015-01-01

More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

Changes of bone mineral density after cementless total hip arthroplasty with two different stems

PubMed Central

Ito, Kouji; Yamamoto, Kengo

2007-01-01

Cementless total hip arthroplasty has achieved reliable long-term results since porous coatings were developed, but postoperative changes around the stem remain poorly documented. In this study, changes of the bone mineral density (BMD) were compared between two types of cementless stem. In group B (28 patients with 31 hips), a straight tapered stem with porous plasma spray coating on the proximal 1/4 was used, while group S (24 patients with 26 hips) was given a fluted, tri-slot stem with porous hydroxyapatite coating on the proximal 1/3. In group B, there was an early decrease of BMD, which recovered after 12 months, indicating that stress shielding was minimal. In group S, however, BMD continued to decrease without recovery. The stem shape and radiological findings suggested that the cause of stress shielding in group S was distal fixation. PMID:17225187

Global fit concept in revision hip arthroplasty for cementless press-fit femoral stems.

PubMed

Canovas, F; LeBeguec, P; Batard, J; Gaillard, F; Dagneaux, L

2017-06-01

A revision stem may be required after a femoral extended trochanteric osteotomy (ETO) is made during revision hip arthroplasty. The two main complications of straight cementless femoral stems are subsidence due to inadequate osteointegration and stress-shielding. We will describe an original revision method with ETO that uses a straight cementless stem. The goal of this method was to achieve the most extensive press-fit possible during stem implantation to improve the transmission of stresses to the bone and to prevent reduction in bone density. The intramedullary preparation was done after closure and fixation of the ETO, which allows impaction of the revision stem with metaphyseal and diaphyseal press-fit. We report encouraging results with preservation of periprosthetic bone stock and good osteointegration of these revision stems at the final follow-up. Pronounced sagittal curvature or large bone defects are contraindications for this technique. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Cementless modular intramedullary nail without bone-on-bone fusion as a salvage procedure in chronically infected total knee prosthesis: long-term results.

PubMed

Scarponi, Sara; Drago, Lorenzo; Romanò, Delia; Logoluso, Nicola; Peccati, Andrea; Meani, Enzo; Romanò, Carlo L

2014-02-01

Our purpose was to evaluate long-term results of two-stage cementless intramedullary nailing without achieving bone-to-bone fusion for treating chronically infected total knee arthroplasty (TKA). Thirty-eight patients treated according to the same protocol were retrospectively evaluated for clinical, functional, laboratory and radiological outcomes. Spacer exchange was necessary for infection persistence in one case. At a minimum two year follow-up, 34 patients (89.5%) showed no infection recurrence; among these 34 patients, 29 (85.3%) reported no or moderate pain [visual analogue scale (VAS) ≤3]; mild to moderate handicap (Lequesne Algofunctional Index < 7.5) was observed in 18 patients (52.9%). No patient underwent revision for aseptic loosening, and no nail breakage was observed. Two-stage cementless intramedullary nailing without achieving bone-to-bone fusion is a viable option for treating chronically infected TKA in selected, complex cases.

Effect of Body Mass Index on Digital Templating for Total Hip Arthroplasty.

PubMed

Sershon, Robert A; Diaz, Alejandro; Bohl, Daniel D; Levine, Brett R

2017-03-01

Digital templating is becoming more prevalent in orthopedics. Recent investigations report high accuracy using digital templating in total hip arthroplasty (THA); however, the effect of body mass index (BMI) on templating accuracy is not well described. Digital radiographs of 603 consecutive patients (645 hips) undergoing primary THA by a single surgeon were digitally templated using OrthoView (Jacksonville, FL). A 25-mm metallic sphere was used as a calibration marker. Preoperative digital hip templates were compared with the final implant size. Hips were stratified into groups based on BMI: BMI <30 (315), BMI 30-35 (132), BMI 35-40 (97), and BMI >40 (101). Accuracy between templating and final size did not vary by BMI for acetabular or femoral components. Digital templating was within 2 sizes of the final acetabular and femoral implants in 99.1% and 97.1% of cases, respectively. Digital templating is an effective means of predicting the final size of THA components. BMI does not appear to play a major role in altering THA digital templating accuracy. Copyright © 2016 Elsevier Inc. All rights reserved.

The boiled-egg technique: a new method for obtaining femoral head autograft used in acetabular defect reconstruction.

PubMed

Bucknall, Vittoria; Mehdi, Ali

2013-09-01

Primary total hip arthroplasty can be complicated by acetabular bony defects, threatening the biomechanical integrity of the prosthesis. Traditionally, when autologous bone is used to pack these defects, it is obtained from thin slices of femoral head in addition to acetabular reamings. We report a novel technique for the acquisition of autologous femoral head bone graft used in the reconstruction of acetabular defects during primary total hip arthroplasty. Copyright © 2013 Elsevier Inc. All rights reserved.

Intraoperative fluoroscopic evaluation of screw placement during pelvic and acetabular surgery.

PubMed

Yi, Chengla; Burns, Sean; Hak, David J

2014-01-01

The surgical treatment of pelvic and acetabular fractures can be technically challenging. Various techniques are available for the reconstruction of pelvic and acetabular fractures. Less invasive percutaneous fracture stabilization techniques, with closed reduction or limited open reduction, have been developed and are gaining popularity in the management of pelvic and acetabular fractures. These techniques require knowledge and interpretation of various fluoroscopic images to ensure appropriate and safe screw placement. Given the anatomic complexity of the intrapelvic structures and the 2-dimensional nature of standard fluoroscopy, multiple images oriented in different planes are needed to assess the accuracy of guide wire and screw placement. This article reviews the fluoroscopic imaging of common screw orientations during pelvic and acetabular surgery.

Deformation of the Durom Acetabular Component and Its Impact on Tribology in a Cadaveric Model—A Simulator Study

PubMed Central

Gu, Yanqing; Wang, Qing; Cui, Weiding; Fan, Weimin

2012-01-01

Background Recent studies have shown that the acetabular component frequently becomes deformed during press-fit insertion. The aim of this study was to explore the deformation of the Durom cup after implantation and to clarify the impact of deformation on wear and ion release of the Durom large head metal-on-metal (MOM) total hips in simulators. Methods Six Durom cups impacted into reamed acetabula of fresh cadavers were used as the experimental group and another 6 size-paired intact Durom cups constituted the control group. All 12 Durom MOM total hips were put through a 3 million cycle (MC) wear test in simulators. Results The 6 cups in the experimental group were all deformed, with a mean deformation of 41.78±8.86 µm. The average volumetric wear rate in the experimental group and in the control group in the first million cycle was 6.65±0.29 mm3/MC and 0.89±0.04 mm3/MC (t = 48.43, p = 0.000). The ion levels of Cr and Co in the experimental group were also higher than those in the control group before 2.0 MC. However there was no difference in the ion levels between 2.0 and 3.0 MC. Conclusions This finding implies that the non-modular acetabular component of Durom total hip prosthesis is likely to become deformed during press-fit insertion, and that the deformation will result in increased volumetric wear and increased ion release. Clinical Relevance This study was determined to explore the deformation of the Durom cup after implantation and to clarify the impact of deformation on wear and ion release of the prosthesis. Deformation of the cup after implantation increases the wear of MOM bearings and the resulting ion levels. The clinical use of the Durom large head prosthesis should be with great care. PMID:23144694

[Perioperative complications after total hip revision surgery and their predictive factors. A series of 181 consecutive procedures].

PubMed

de Thomasson, E; Guingand, O; Terracher, R; Mazel, C

2001-09-01

We conducted a retrospective study to assess morbidity and mortality in patients undergoing revision total hip arthroplasty (THA) procedures. Perioperative complications were recorded in 181 revision procedures (162 patients) performed between January 1995 and March 1999 (117 bipolar revisions and 64 acetabular isolated revisions). There were 86 complications (68 patients) leading to 21 new revisions. About half (50/86) were related to the surgical procedure (dislocation, femoral fracture, infection.). Life-threatening complications (3.6%) ended in patient death in 1.6% of the cases. Complications were more frequent in patients with an ASA score=3 (p<0.01) or aged over 75 years (p<0.05). Age was also predictive of femoral misalignment and fracture (p<0.05). Dislocations (8.8%) were observed more frequently in patients who had undergone more than 2 procedures prior to the revision (p<0.05) (4.8% of the dislocations in patients undergoing a first revision procedure and 14.3% in the others). In addition, peroperative blood loss and duration of the procedure were significantly greater in case of bipolar replacement than for isolated acetabular replacement (sigma > 1.96). Our experience and data in the literature point to the important age factor in the development of complications. Preservation of a well-fixed femoral component does not appear to worsen prognosis and leads to fewer complications than bipolar changes. The decision to revise a THA must take into consideration the functional impairment but also the risks inherent in revision procedures, particularly in old patients who have undergone several procedures. Revising the acetabular component alone can be an interesting option if the femoral component remains well-fixed although our follow-up is insufficient to determine whether this attitude provides better long-term outcome than complete biopolar revision. Better patient selection and improved operative technique, in particular in femur preparation, should help reduce morbidity and mortality in this type of procedure.

Deformation of the Durom acetabular component and its impact on tribology in a cadaveric model--a simulator study.

PubMed

Liu, Feng; Chen, Zhefeng; Gu, Yanqing; Wang, Qing; Cui, Weiding; Fan, Weimin

2012-01-01

Recent studies have shown that the acetabular component frequently becomes deformed during press-fit insertion. The aim of this study was to explore the deformation of the Durom cup after implantation and to clarify the impact of deformation on wear and ion release of the Durom large head metal-on-metal (MOM) total hips in simulators. Six Durom cups impacted into reamed acetabula of fresh cadavers were used as the experimental group and another 6 size-paired intact Durom cups constituted the control group. All 12 Durom MOM total hips were put through a 3 million cycle (MC) wear test in simulators. The 6 cups in the experimental group were all deformed, with a mean deformation of 41.78 ± 8.86 µm. The average volumetric wear rate in the experimental group and in the control group in the first million cycle was 6.65 ± 0.29 mm(3)/MC and 0.89 ± 0.04 mm(3)/MC (t = 48.43, p = 0.000). The ion levels of Cr and Co in the experimental group were also higher than those in the control group before 2.0 MC. However there was no difference in the ion levels between 2.0 and 3.0 MC. This finding implies that the non-modular acetabular component of Durom total hip prosthesis is likely to become deformed during press-fit insertion, and that the deformation will result in increased volumetric wear and increased ion release. This study was determined to explore the deformation of the Durom cup after implantation and to clarify the impact of deformation on wear and ion release of the prosthesis. Deformation of the cup after implantation increases the wear of MOM bearings and the resulting ion levels. The clinical use of the Durom large head prosthesis should be with great care.

EFFECTS OF EPISODIC SUBLUXATION EVENTS ON THIRD BODY INGRESS AND EMBEDMENT IN THE THA BEARING SURFACE

PubMed Central

Heiner, Anneliese D.; Lundberg, Hannah J.; Baer, Thomas E.; Pedersen, Douglas R.; Callaghan, John J.; Brown, Thomas D.

2008-01-01

In total joint arthroplasty, third body particle access to the articulating surfaces results in accelerated wear. Hip joint subluxation is an under-recognized means by which third body particles could potentially enter the otherwise closely conforming articular bearing space. The present study was designed to test the hypothesis that, other factors being equal, even occasional events of femoral head subluxation greatly increase the number of third body particles that enter the bearing space and become embedded in the acetabular liner, as compared to level walking cycles alone. Ten metal-on-polyethylene hip joint head-liner pairs were tested in a multi-axis joint motion simulator, with CoCrMo third body particles added to the synovial fluid analog. All component pairs were tested for two hours of level walking; half also were subjected to twenty intermittent subluxation events. The number and location of embedded particles on the acetabular liners were then determined. Subluxation dramatically increased the number of third body particles embedded in the acetabular liners, and it considerably increased the amount of scratch damage on the femoral heads. Since both third body particles and subluxation frequently occur in contemporary total hip arthroplasty, their potent synergy needs to be factored prominently into strategies to minimize wear. PMID:18561936

Bipolar hip arthroplasty for avascular necrosis of femoral head in young adults

PubMed Central

Dudani, Baldev; Shyam, Ashok K; Arora, Pankush; Veigus, Arjun

2015-01-01

Background: Bipolar hip arthroplasty (BHA) is one of the options for treatment of avascular necrosis (AVN) of the femoral head. Acetabular erosion and groin pain are the most allowing for gross motion between the common complications. We propose that these complications are secondary to improper acetabular preparation allowing for motion between the BHA head and the acetabulum. Materials and Methods: The current study retrospectively evaluated patients’records from case files and also called them for clinical and radiological followup. 96 hips with AVN of the femoral head treated with BHA were included in the study. All patients were males with a mean age of 42 years (range 30-59 years). In all cases, the acetabulum was gently reamed till it became uniformly concentric to achieve tight fitting trial cup. Clinical followup using Harris hip score (HHS) and radiological study for cup migration were done at followup. Results: The mean followup was 7.52 years (range 4-16 years). The HHS significantly improved from a preoperative value of 39.3 (range, 54-30) to a postoperative value of 89.12 (range 74-96). According to HHS grades, the final outcome was excellent in 52 hips, good in 28 and fair in 16 hips. Hip and groin pain was reported in four hips (5%), but did not limit activity. Subsidence (less than 5 mm) of the femoral component was seen in 8 cases. Subgroup analysis showed patients with Ficat Stage 3 having better range of motion, but similar HHS as compared to Ficat Stage 4 patients. Conclusion: Bipolar hip arthroplasty (BHA) using tight fitting cup and acetabular reaming in AVN hip has a low incidence of groin pain, acetabular erosion and revision in midterm followup. Good outcome and mid term survival can be achieved irrespective of the Ficat Stage. PMID:26015634

Monitoring the quality of total hip replacement in a tertiary care department using a cumulative summation statistical method (CUSUM).

PubMed

Biau, D J; Meziane, M; Bhumbra, R S; Dumaine, V; Babinet, A; Anract, P

2011-09-01

The purpose of this study was to define immediate post-operative 'quality' in total hip replacements and to study prospectively the occurrence of failure based on these definitions of quality. The evaluation and assessment of failure were based on ten radiological and clinical criteria. The cumulative summation (CUSUM) test was used to study 200 procedures over a one-year period. Technical criteria defined failure in 17 cases (8.5%), those related to the femoral component in nine (4.5%), the acetabular component in 32 (16%) and those relating to discharge from hospital in five (2.5%). Overall, the procedure was considered to have failed in 57 of the 200 total hip replacements (28.5%). The use of a new design of acetabular component was associated with more failures. For the CUSUM test, the level of adequate performance was set at a rate of failure of 20% and the level of inadequate performance set at a failure rate of 40%; no alarm was raised by the test, indicating that there was no evidence of inadequate performance. The use of a continuous monitoring statistical method is useful to ensure that the quality of total hip replacement is maintained, especially as newer implants are introduced.

Is anatomic acetabular orientation related to pelvic morphology? CT analysis of 150 healthy pelvises.

PubMed

Sautet, P; Giorgi, H; Chabrand, P; Tropiano, P; Argenson, J-N; Parratte, S; Blondel, B

2018-05-01

Links between sagittal spinal alignment and acetabular orientation attract considerable research attention with the goal of optimising prosthetic cup position. However, whether pelvic incidence (PI) is related to anatomic acetabular orientation remains unknown. We therefore conducted a radiological study with the following objectives: to look for correlations between PI and anatomic acetabular parameters; to describe the sacro-pubic angle (SPA), defined by fixed bony pelvic landmarks, and its relations with acetabular anteversion; and to determine whether anatomical parameters (PI and SPA) correlate with demographic characteristics. PI correlates with anatomical acetabular parameters. We conducted a computed tomography (CT) study of the pelvises of 150 patients free of degenerative disease. Three parameters were measured: anatomic acetabular orientation in the Lewinnek reference plane, PI, and the SPA subtended by the line connecting the midpoint of the sacral endplate to the pubic symphysis and the anterior pelvic plane. Statistical tests were performed to look for correlations among these parameters. Intra-observer and inter-observer reproducibility was considered highly satisfactory (inter-class correlation coefficient, >86% and >82%, respectively). Mean PI was 58.6°±10.2° (range, 32.8°-97.6°), with no significant differences between genders or across age groups. Mean SPA was 34.7°±5.5° (range, 18.3°-49.8°). Mean anatomic acetabular anteversion (AAA) was greater in females (23.4°; range, 11.5°-34.5°) than in males (20°; range, 7.5°-34.5°) (P<0.001). PI did not correlate with any of the acetabular parameters (PI/AAA, r=0.8 and P=0.33; PI/acetabular inclination on the horizontal, r=-0.96 and P=0.24). SPA correlated significantly with both PI (r=0.33 and P<0.001) and AAA (r=0.33 and P<0.001). This CT study of normal pelvises showed that AAA was significantly greater in females and that SPA correlated significantly with both PI and acetabular anteversion. SPA could serve to define the "theoretical" AAA of each individual patient and could thus be incorporated into surgical planning protocols or intra-operative guidance methods for hip replacement surgery. IV, retrospective study with no control group. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Combat-related acetabular fractures: Outcomes of open versus closed injuries.

PubMed

Purcell, Richard L; Donohue, Michael A; Saxena, Sameer K; Gordon, Wade T; Lewandowski, Louis L

2018-02-01

Since the onset of the Global War on Terror close to 50,000 United States service members have been injured in combat, many of these injuries would have previously been fatal. Among these injuries, open acetabular fractures are at an increased number due to the high percentage of penetrating injuries such as high velocity gunshot wounds and blast injuries. These injuries lead to a greater degree of contamination, and more severe associated injuries. There is a significantly smaller proportion of the classic blunt trauma mechanism typically seen in civilian trauma. We performed a retrospective review of the Department of Defense Trauma Registry into which all US combat-injured patients are enrolled, as well as reviewed local patient medical records, and radiologic studies from March 2003 to April 2012. Eighty seven (87) acetabular fractures were identified with 32 classified as open fractures. Information regarding mechanism of injury, fracture pattern, transfusion requirements, Injury Severity Score (ISS), and presence of lower extremity amputations was analyzed. The mechanism of injury was an explosive device in 59% (n=19) of patients with an open acetabular fracture; the remaining 40% (n=13) were secondary to ballistic injury. In contrast, in the closed acetabular fracture cohort 38% (21/55) of fractures were due to explosive devices, and all remaining (n=34) were secondary to blunt trauma such as falls, motor vehicle collisions, or aircraft crashes. Patients with open acetabular fractures required a median of 17units of PRBC within the first 24h after injury. The mean ISS was 32 in the open group compared with 22 in the closed group (p=0.003). In the open fracture group nine patients (28%) sustained bilateral lower extremity amputations, and 10 patients (31%) ultimately underwent a hip disarticulation or hemi-pelvectomy as their final amputation level. Open acetabular fractures represent a significant challenge in the management of combat-related injuries. High ISS and massive transfusion requirements are common in these injuries. This is one of the largest series reported of open acetabular fractures. Open acetabular fractures require immediate damage control surgery and resuscitation as well as prolonged rehabilitation due to their severity. The dramatic number of open acetabular fractures (37%) in this review highlights the challenge in treatment of combat related acetabular fractures. Published by Elsevier Ltd.

[IMAGING ANALYSIS OF ACETABULAR CUP POSITIONS IN TOTAL HIP ARTHROPLASTY FOR ADULTS WITH ACETABULAR DYSPLASIA].

PubMed

Sun, Hong; Fang, Shuying; Yang, Zibo; Zhang, Zhiqi; Kang, Yan; Zhang, Ziji; Liao, Weiming; Fu, Ming; Wu, Peihui

2016-11-08

To investigate the influence of the degree of acetabular deformity and the learning-curve on the acetabular cup positions in total hip arthroplasty (THA) for adults with developmental dysplasia of hip (DDH). Between January 2008 and December 2015, 130 patients (144 hips) with DDH underwent primary THA, and the clinical data were analyzed retrospectively. Fifty-three patients (59 hips) were admitted before 2012, and 77 patients (85 hips) were treated after 2012. There were 32 males and 98 females, aged from 31 to 83 years (mean, 61). Unilateral replacement was performed in 116 cases and bilateral replacement in 14 cases. Of 144 hips, 48 hips were rated as Crowe type I, 57 hips as type II, and 39 hips as type of III/IV. The standard pelvic radiograph was taken within 1 week after operation. The mediCAD software was adopted to measure the angle of anteversion and abduction, bony coverage, and the distance between true rotating center and optimal rotating center to the connection of teardrops and the horizontal distance between two centers to evaluate the qualified rate of acetabular cup positions. Compared with the patients with the same type in 2013-2015 group, the anteversion angle and qualified rate of acetabular cup position significantly decreased in patients with Crowe I ( P <0.05); the horizontal distance significantly increased and qualified rate of acetabular cup position significantly decreased in patients with Crowe II ( P <0.05); and the anteversion angle significantly decreased and the horizontal distance significantly increased in patients with Crowe III/IV ( P <0.05) in 2008-2012 group. But no significant difference was shown in the other indexes ( P >0.05). In all Crowe types, the vertical distance between the true rotating center and the optimal rotating center increased with the degree of acetabular deformity in both 2008-2012 group and 2013-2015 group, showing significant difference ( P <0.05), but no significant difference was found in the other indexes ( P >0.05). For adults with acetabular dysplasia, there are high potential risks for unsatisfactory acetabular cup positions during primary THA. So it is necessary to evaluate acetabular deformities and to sum up operative experience so as to improve the accuracy of cups installation.

Scanning Electron Microscopy and Energy-Dispersive X-Ray Spectroscopy as a Valuable Tool to Investigate the Ultra-High-Molecular-Weight Polyethylene Wear Mechanisms and Debris in Hip Implants.

PubMed

Schappo, Henrique; Gindri, Izabelle M; Cubillos, Patrícia O; Maru, Marcia M; Salmoria, Gean V; Roesler, Carlos R M

2018-01-01

The use of scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS) was investigated to understand the wear mechanisms from a metal-on-polyethylene bearing couple. Morphological features of femoral head acetabular liner, and isolated particles resulting from hip wear testing were evaluated. EDS was proposed to investigate the polymeric nature of the particles isolated from the wear testing. In this work, 28-mm conventional ultra-high-molecular-weight polyethylene acetabular liners paired with metallic heads were tested in a hip wear simulator over 2 million cycles. SEM-EDS was employed to investigate wear mechanisms on hip implant components and associated wear debris. SEM showed worn surfaces for both hip components, and a significant volume of ultra-high-molecular-weight polyethylene wear particles resulting from hip wear testing. Particles were classified into 3 groups, which were then correlated to wear mechanisms. Group I had particles with smooth surfaces, group II consisted of particles with rough surfaces, and group III comprised aggregate-like particles. Group I EDS revealed that particles from groups I and II had a high C/O ratio raising a concern about the particle source. On the other hand, particles from group III had a low C/O ratio, supporting the hypothesis that they resulted from the wear of acetabular liner. Most of particles identified in group III were in the biologically active size range (0.3 to 20 μm). The use of optical and electron microscopy enabled the morphological characterization of worn surfaces and wear debris, while EDS was essential to elucidate the chemical composition of isolated debris. Copyright © 2017 Elsevier Inc. All rights reserved.

Screws are not needed when secure interference fit of uncemented acetabular components is adequate: a 5- to 15-year follow-up with clinical and radiological analysis.

PubMed

García-Rey, Eduardo

2017-05-12

Even with good surgical preparation, adequate primary stability of the acetabular component is not always achieved after primary total hip replacement (THR). We hypothesise that adequate bone preparation for appropriate cortical loading would allow us to avoid screw use. A total of 791 uncemented cups were analysed to compare the need for screws to obtain primary fixation in 5 different designs. Arthritic hips with inflammatory arthritis or severe congenital hip disease were excluded. A press-fit technique was first tried in all hips and screws were only used when strictly needed. Radiological acetabular shape and postoperative cup position were assessed in all hips. The mean follow-up was 9.6 (5-15) years. Screws were required in 155 hips (19.6%). We could not detect any difference in the percentage of screw use between designs. We found that female patients (odds ratio [OR] 2.06; 95% confidence interval [CI], 1.41-3.02) and cups with a greater distance to the hip rotation centre on the postoperative radiograph (OR 1.69; 95% CI, 1.17-2.45) had a higher risk for screw use. A greater anteversion of the cup had a lower risk for screw use (OR 0.96; 95% CI, 0.94-0.99). At latest follow-up no hips had needed revision for aseptic loosening. Good intraoperative technique is not enough to avoid screw use since more accurate cup position and reconstruction of the hip rotation centre are required for an adequate interference fit. A press-fit technique can provide similar mid-term results to screw use in hips without severe deformities.

The cementless anatomic medullary locking femoral component: an independent clinical and radiographic assessment

PubMed Central

Chess, David G.; Grainger, R. Wayne; Phillips, Tom; Zarzour, Zane D.; Sheppard, Bruce R.

1996-01-01

Objective To review the clinical performance of the anatomic medullary locking (AML) femoral stem in total hip arthroplasty. Design A clinical and radiographic review. Setting A tertiary lower limb joint replacement centre. Patients Two hundred and twenty-one patients with noninflammatory gonarthrosis. Interventions Two hundred and twenty-seven primary total hip arthroplasties with the noncemented AML component completed by two surgeons. Main Outcome Measures Independent review by two experienced reviewers of the postoperative Harris hip score, radiographs of component fixation, size and degree of diaphyseal fill. Results Harris hip score was 84 (range from 43 to 98); component fixation showed bone ingrowth in 41%, stable fixation with fibrous ingrowth in 56% and unstable fixation in 3%; severe thigh pain in 4% of cases correlated with unstable fixation, and there was mild thigh pain in 20% of cases. Conclusion The AML femoral stem performs well in replacement arthroplasty compared with other noncemented stems. PMID:8857987

Acetabular fractures: anatomic and clinical considerations.

PubMed

Lawrence, David A; Menn, Kirsten; Baumgaertner, Michael; Haims, Andrew H

2013-09-01

Classifying acetabular fractures can be an intimidating topic. However, it is helpful to remember that there are only three basic types of acetabular fractures: column fractures, transverse fractures, and wall fractures. Within this framework, acetabular fractures are classified into two broad categories: elementary or associated fractures. We will review the osseous anatomy of the pelvis and provide systematic approaches for reviewing both radiographs and CT scans to effectively evaluate the acetabulum. Although acetabular fracture classification may seem intimidating, the descriptions and distinctions discussed and shown in this article hopefully make the topic simpler to understand. Approach the task by recalling that there are only three basic types of acetabular fractures: column fractures (coronally oriented on CT images), transverse fractures (sagittally oriented on CT images), and wall fractures (obliquely oriented on CT images). We have provided systematic approaches for reviewing both conventional radiographs and CT scans to effectively assess the acetabulum. The clinical implications of the different fracture patterns have also been reviewed because it is critically important to include pertinent information for our clinical colleagues to provide the most efficient and timely clinical care.

Fretting and Corrosion Between a Metal Shell and Metal Liner May Explain the High Rate of Failure of R3 Modular Metal-on-Metal Hips.

PubMed

Ilo, Kevin C; Derby, Emma J; Whittaker, Robert K; Blunn, Gordon W; Skinner, John A; Hart, Alister J

2017-05-01

The R3 acetabular system used with its metal liner has higher revision rates when compared to its ceramic and polyethylene liner. In June 2012, the medical and healthcare products regulatory agency issued an alert regarding the metal liner of the R3 acetabular system. Six retrieved R3 acetabular systems with metal liners underwent detailed visual analysis using macroscopic and microscopic techniques. Visual analysis discovered corrosion on the backside of the metal liners. There was a distinct border to the areas of corrosion that conformed to antirotation tab insertions on the inner surface of the acetabular shell, which are for the polyethylene liner. Scanning electron microscopy indicated evidence of crevice corrosion, and energy-dispersive X-ray analysis confirmed corrosion debris rich in titanium. The high failure rate of the metal liner option of the R3 acetabular system may be attributed to corrosion on the backside of the liner which appear to result from geometry and design characteristics of the acetabular shell. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of acetabular reinforcement ring with hook for acetabular dysplasia clarified by three-dimensional finite element analysis.

PubMed

Zhao, Xin; Chosa, Etsuo; Yamako, Go; Watanabe, Shinji; Deng, Gang; Totoribe, Koji

2013-12-01

The objective of this study was to biomechanically determine the effect of the severity of acetabular dysplasia, number and positions of screws and type of bone graft material used on the initial fixation strength of the acetabular reinforcement ring with hook (Ganz ring) using the finite element method. Relative micromotion increased as the severity of acetabular dysplasia increased and tended to decrease as the number of screws increased, but varied according to screw placement position. Increased strength of the bone graft material led to decreased relative micromotion. Biomechanically, the Ganz ring can be placed securely using 3 screws in patients with Crowe 1 dysplasia. However, in patients with Crowe 2 or higher dysplasia, it is necessary to spread at least 4 screws across an area of good host bone. © 2013.

Results of revision total knee arthroplasty using press-fit cementless stem.

PubMed

Iamaguchi, Maurício Masasi; de Castro, Fernando Bley Vicente; Gobbi, Riccardo Gomes; Tirico, Luis Eduardo Passarelli; Pécora, José Ricardo; Camanho, Gilberto Luis

2013-01-01

To show our experience with press-fit cementless stem and metaphyseal fixation with cement in a selected series of patients who underwent revision total knee arthroplasty. Thirty-four patients (35 knees) underwent revision total knee arthroplasty using the press-fit technique. Minimum follow-up was one year (mean 2.2 years) with a maximum length of three years. Of 34 patients, 20 were women and 14 were men. There was one death due to causes not related to arthroplasty and one patient dropout. There were no cases in which further review was necessary. Patients who underwent revision had clinical and functional improvement demonstrated by the results of the KSS, results of the SF-36 quality of life questionnaire, through gains in range of motion and improved limb alignment. There was postoperative clinical and functional improvement in comparison to the preoperative status in revision total knee arthroplasty with press-fit cementless stem. Level of Evidence IV, Case series.

Spine–hip relations in patients with hip osteoarthritis

PubMed Central

Rivière, Charles; Lazic, Stefan; Dagneaux, Louis; Van Der Straeten, Catherine; Cobb, Justin; Muirhead-Allwood, Sarah

2018-01-01

Patients with hip osteoarthritis often have an abnormal spine-hip relation (SHR), meaning the presence of a clinically deleterious spine-hip and/or hip-spine syndrome. Definition of the individual SHR is ideally done using the EOS® imaging system or, if not available, with conventional lumbopelvic lateral radiographs. By pre-operatively screening patients with abnormal SHR, it is possible to refine total hip replacement (THR) surgical planning, which may improve outcomes. An important component of the concept of kinematically aligned total hip arthroplasty (KA THA) consists of defining the optimal acetabular cup design and orientation based on the assessment of an individual’s SHR, and use of the transverse acetabular ligament to adjust the cup positioning. The Bordeaux classification might advance the understanding of SHR and hopefully help improve THR outcomes. Cite this article: EFORT Open Rev 2018;3:39-44. DOI: 10.1302/2058-5241.3.170020 PMID:29657844

Radiographic parameters associated with pain following total hip and surface arthroplasty.

PubMed

Nam, Denis; Sauber, Timothy J; Barrack, Toby; Johnson, Staci R; Brooks, Peter J; Nunley, Ryan M

2015-03-01

Pain following total hip arthroplasty (THA) and surface arthroplasty (SRA) remains a significant source of patient dissatisfaction. Two hundred twenty-four SRA and 196 THA patients completed a pain drawing questionnaire and postoperative radiographic measurements of component positioning were performed. In the SRA cohort, 11 of 21 patients (52%) with acetabular uncoverage of ≥5 mm versus 43 of 147 (29%) with acetabular uncoverage of ≤4.9 mm reported groin pain (P=.03). In the THA cohort, an increased distal-third canal fill ratio and a lower canal calcar ratio trended towards a higher incidence of thigh pain (P=.10 and .06), while a decreased mid-third canal fill ratio was associated with increased severity of thigh pain (P=.04). This study identifies associations between radiographic findings and pain following THA and SRA. Copyright © 2014 Elsevier Inc. All rights reserved.

[Pelvic reconstructions after bone tumor resection].

PubMed

Anract, Philippe; Biau, David; Babinet, Antoine; Tomeno, Bernard

2014-02-01

The three more frequent primitive malignant bone tumour which concerned the iliac bone are chondrosarcoma, following Ewing sarcoma and osteosarcoma. Wide resection remains the most important part of the treatment associated with chemotherapy for osteosarcoma and the Ewing sarcoma. Iliac wing resections and obdurate ring don't required reconstruction. However, acetabular resections and iliac wing resection with disruption of the pelvic ring required reconstruction to provide acceptable functional result. Acetabular reconstruction remains high technical demanding challenge. After isolated acetabular resection or associated to obdurate ring, our usual method of reconstruction is homolateral proximal femoral autograft and total hip prosthesis but it is possible to also used : saddle prosthesis, Mac Minn prosthesis with auto or allograft, modular prosthesis or custom made prosthesis, massive allograft with or without prosthesis and femoro-ilac arthrodesis. After resection of the iliac wing plus acetabulum, reconstruction can be performed by femoro-obturatrice and femora-sacral arthrodesis, homolateral proximal femoral autograft and prosthesis, femoral medialisation, massive allograft and massive allograft. Carcinological results are lesser than resection for distal limb tumor, local recurrence rate range 17 to 45%. Functional results after Iliac wing and obdurate ring are good. However, acetabular reconstruction provide uncertain functional results. The lesser results arrive after hemipelvic or acetabular and iliac wing resection-reconstruction, especially when gluteus muscles were also resected. The most favourable results arrive after isolated acetabular or acetabular plus obturateur ring resection-reconstruction.

A novel electromagnetic navigation tool for acetabular surgery.

PubMed

Lehmann, Wolfgang; Rueger, Johannes M; Nuechtern, Jakob; Grossterlinden, Lars; Kammal, Michael; Hoffmann, Michael

2015-10-01

Acetabular fracture surgery is demanding and screw placement along narrow bony corridors remains challenging. It necessitates x-ray radiation for fluoroscopically assisted screw insertion. The purpose of this cadaver study was to evaluate the feasibility, accuracy and operation time of a novel electromagnetic navigation system for screw insertion along predefined acetabular corridors. A controlled laboratory study with a total of 24 electromagnetically navigated screw insertions was performed on 8 cadaveric acetabula. 3 peri-acetabular bony corridors (QSS, Quadrilateral Surface Screw; IAS, Infra-Acetabular Screw; PCS, Posterior Column Screw) were defined and screws were placed in a defined order without fluoroscopy. Operation time was documented. Postoperative CT scans were performed to analyse accuracy of screw placement. Mean cadaver age was 70.4 ± 11.7. Successful screw placement was accomplished in 22 out of 24 (91.7%) cases. The overall mean time for all 3 acetabular screws was 576.6 ± 75.9s. All 3 complications occurred during the placement of the IAS due to an impassable narrow bony corridor. QSS mean length was 50 ± 5mm, IAS mean length was 85 ± 10mm and PCS mean length was 120 ± 5mm. In this cadaver study the novel electromagnetic navigation system was feasible to allow accurate screw placement without fluoroscopy in defined narrow peri-acetabular bony corridors. Copyright © 2015 Elsevier Ltd. All rights reserved.

What Is the Rerevision Rate After Revising a Hip Resurfacing Arthroplasty? Analysis From the AOANJRR.

PubMed

Wong, James Min-Leong; Liu, Yen-Liang; Graves, Stephen; de Steiger, Richard

2015-11-01

More than 15,000 primary hip resurfacing arthroplasties have been recorded by the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) with 884 primary procedures requiring revision for reasons other than infection, a cumulative percent revision rate at 12 years of 11%. However, few studies have reported the survivorship of these revision procedures. (1) What is the cumulative percent rerevision rate for revision procedures for failed hip resurfacings? (2) Is there a difference in rerevision rate among different types of revision or bearing surfaces? The AOANJRR collects data on all primary and revision hip joint arthroplasties performed in Australia and after verification against health department data, checking of unmatched procedures, and subsequent retrieval of unreported procedures is able to obtain an almost complete data set relating to hip arthroplasty in Australia. Revision procedures are linked to the known primary hip arthroplasty. There were 15,360 primary resurfacing hip arthroplasties recorded of which 884 had undergone revision and this was the cohort available to study. The types of revisions were acetabular only, femoral only, or revision of both acetabular and femoral components. With the exception of the acetabular-only revisions, all revisions converted hip resurfacing arthroplasties to conventional (stemmed) total hip arthroplasties (THAs). All initial revisions for infection were excluded. The survivorship of the different types of revisions and that of the different bearing surfaces used were estimated using the Kaplan-Meier method and compared using Cox proportional hazard models. Cumulative percent revision was calculated by determining the complement of the Kaplan-Meier survivorship function at that time multiplied by 100. Of the 884 revisions recorded, 102 underwent further revision, a cumulative percent rerevision at 10 years of 26% (95% confidence interval, 19.6-33.5). There was no difference in the rate of rerevision between acetabular revision and combined femoral and acetabular revision (hazard ratio [HR], 1.06 [0.47-2], p = 0.888), femoral revision and combined femoral and acetabular revision (HR, 1.00 [0.65-2], p = 0.987), and acetabular revision and femoral revision (HR, 1.06 [0.47-2], p = 0.893). There was no difference in the rate of rerevision when comparing different bearing surfaces (metal-on-metal versus ceramic-on-ceramic HR, 0.46 [0.16-1.29], p = 0.141; metal-on-metal versus ceramic-on-crosslinked polyethylene HR, 0.51 [0.15-1.76], p = 0.285; metal-on-metal versus metal-on-crosslinked polyethylene HR, 0.62 [0.20-1.89], p = 0.399; and metal-on-metal versus oxinium-on-crosslinked polyethylene HR, 0.53 [0.14-2.05], p = 0.356). Revision of a primary hip resurfacing arthroplasty is associated with a high risk of rerevision. This study may help surgeons guide their patients about the outcomes in the longer term after the first revision of hip resurfacing arthroplasty. Level III, therapeutic study.

Efficacy and safety of the topical application of tranexamic acid in primary cementless hip arthroplasty: prospective, randomised, double-blind and controlled study.

PubMed

Tavares Sánchez-Monge, F J; Aguado Maestro, I; Bañuelos Díaz, A; Martín Ferrero, M Á; García Alonso, M F

To evaluate the efficacy of topical tranexamic acid topical in cementless total hip arthroplasty from the point of view of bleeding, transfusion requirements and length of stay, and describe the complications of use compared to a control group. A prospective, randomised, double-blinded and controlled study including all patients undergoing cementless total hip arthroplasty in our centre between June 2014 and July 2015. Blood loss was estimated using the formula described by Nadler and Good. The final analysis included 119 patients. The decrease in haemoglobin after surgery was lower in the tranexamic acid group (3.28±1.13g/dL) than in the controls (4.03±1.27g/dL, P=.001) and estimated blood loss (1,216.75±410.46mL vs. 1,542.12±498.97mL, P<.001), the percentage of transfused patients (35.9% vs. 19.3%, P<.05) and the number of transfused red blood cell units per patient (0.37±0.77 vs. 0.98±1.77; P<.05). There were no differences between groups in the occurrence of complications or length of stay. The use of topical tranexamic acid in cementless total hip arthroplasty results in a decrease in bleeding and transfusion requirements without increasing the incidence of complications. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Bipolar Hemarthroplasty Using Cementless Conical Stem for Treatment of Dorr Type B and C Femoral Neck Fracture.

PubMed

Kang, Jeong Hoon; Lee, Sang Hong; Jung, Sung

2015-12-01

The current study aims to evaluate the clinical and the radiological outcome of bipolar hemiarthroplasty using cementless cone stem to treat osteoporotic femoral neck fracture and compare the results according to the proximal femur geometry. Seventy-five hips (75 patients) that underwent bipolar hemiarthroplasty with cementless cone stem between September 2006 and December 2011 were analyzed. The minimum follow-up period was 3 years. Thirty-three hips were classified as type B and 41 as type C. The clinical outcome was assessed using Harris hip score and the walking ability score. Radiographic evaluation was performed to evaluate the stability of the prosthesis. At the most recent follow up, the mean Harris hip score was 86 (range, 70-92) and 65% recovered to preoperative ambulatory status. In the radiographic exam, stable stem fixation was achieved in all cases. For the complications, eight hips developed deep vein thrombosis while three hips showed heterotopic ossification. Dislocation and delayed deep infection occurred in one hip resepectively. There were no significance differences in Harris hip score and walking ability score when the type B group was compare with the type C. Bipolar hemiarthroplasty with cementless cone stem showed an excellent early outcome both clinically and radiographically regardless of the shape of the proximal femur. We believe this prosthesis can provide early stability to the Dorr type B and C femur and is an effective treatment for treating osteoporotic femoral neck fracture.

[Contact characteristics research of acetabular weight-bearing area with different internal fixation methods after compression fracture of acetabular dome].

PubMed

Xu, Bowen; Zhang, Qingsong; An, Siqi; Pei, Baorui; Wu, Xiaobo

2017-08-01

To establish the model of compression fracture of acetabular dome, and to measure the contact characteristics of acetabular weight-bearing area of acetabulum after 3 kinds of internal fixation. Sixteen fresh adult half pelvis specimens were randomly divided into 4 groups, 4 specimens each group. Group D was the complete acetabulum (control group), and the remaining 3 groups were prepared acetabular dome compression fracture model. The fractures were fixed with reconstruction plate in group A, antegrade raft screws in group B, and retrograde raft screws in group C. The pressure sensitive films were attached to the femoral head, and the axial compression test was carried out on the inverted single leg standing position. The weight-bearing area, average stress, and peak stress were measured in each group. Under the loading of 500 N, the acetabular weight-bearing area was significantly higher in group D than in other 3 groups ( P <0.05), and the average stress and peak stress were significantly lower than in other 3 groups ( P <0.05). The acetabular weight-bearing area were significantly higher in group B and group C than in group A, and the average stress and peak stress were significantly lower than in group A ( P <0.05). There was no significant difference in the above indexes between group B and group C ( P >0.05). For the compression fracture of the acetabular dome, the contact characteristics of the weight-bearing area can not restore to the normal level, even if the anatomical reduction and rigid internal fixation were performed; compared with the reconstruction plate fixation, antegrade and retrograde raft screws fixations can increase the weight-bearing area, reduce the average stress and peak stress, and reduce the incidence of traumatic arthritis.

/sup 99m/Tc-methylene diphosphonate bone imaging in the evaluation of total hip prostheses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiss, P.E.; Mall, J.C.; Hoffer, P.B.

1979-12-01

A retrospective study was performed to determine the accuracy of /sup 99m/Tc-methylene diphosphonate bone imaging in the evaluation of total hip arthroplasty for loosening and/or infection. Using focally increased activity at the tip of the femoral component or in the region of the acetabular component as a criterion, the examination was 77% specific and 100% sensitive for loosening and/or infection. A possible explanation for the increased uptake at the tip of the femoral component and the role of this examination in the management of a painful total hip prosthesis are discussed.

Dissociation of modular total hip arthroplasty at the neck-stem interface without dislocation.

PubMed

Kouzelis, A; Georgiou, C S; Megas, P

2012-12-01

Modular femoral and acetabular components are now widely used, but only a few complications related to the modularity itself have been reported. We describe a case of dissociation of the modular total hip arthroplasty (THA) at the femoral neck-stem interface during walking. The possible causes of this dissociation are discussed. Successful treatment was provided with surgical revision and replacement of the modular neck components. Surgeons who use modular components in hip arthroplasties should be aware of possible early complications in which the modularity of the prostheses is the major factor of failure.

Cup-cage construct for acute fractures of the acetabulum, re-defining indications.

PubMed

Chana-Rodríguez, Francisco; Villanueva-Martínez, Manuel; Rojo-Manaute, Jose; Sanz-Ruíz, Pablo; Vaquero-Martín, Javier

2012-12-01

Acetabular fractures in the elderly are challenging injuries. The use of a trabecular metal acetabular cage was investigated as the treatment option in a series of elderly patients with acetabular fractures. At a 2-year follow up, 6 elderly patients were found to have mimimum pain, increased function, and increased scores using the Merle d'Aubigné and Postel system modified by Charnley. Radiographically, the areas of morsellised autograft that surrounded the cups were seen to have incorporated uniformly well, and the acetabular fractures were healed within six months after surgery. No mechanical failure, screw breakage, loosening, or migration was noticed. This novel indication of the cup-cage construction that uses revision techniques, for selected patients and fractures, to achieve an acute stable reconstruction, should be considered as an alternative reconstruction option in elderly patients presenting with acetabular fractures. Copyright © 2012 Elsevier Ltd. All rights reserved.

Total hip arthroplasty of dysplastic hip after previous Chiari pelvic osteotomy.

PubMed

Minoda, Yukihide; Kadowaki, Toru; Kim, Mitsunari

2006-08-01

Many reports have suggested that Chiari pelvic osteotomy would improve the results of acetabular component placement and fixation in subsequent total hip arthroplasty. However, little is known concerning the biomechanical, radiological, and clinical effects of Chiari pelvic osteotomy on subsequent total hip arthroplasty. Ten total hip arthroplasties for developmental dysplasia of the hip after previous Chiari pelvic osteotomy (Chiari group) were compared with 20 total hip arthroplasties for developmental dysplasia of the hip without previous surgery (control group). Preoperative patient demographic data and operative technique were well matched between the groups. The mean duration of follow-up was 3.0 years. Biomechanical, radiological, and clinical evaluations were performed. No acetabular or femoral components exhibited loosening. All patients had good or excellent clinical score according to the Merle d'Aubigne-Postel rating system at the most recent follow-up. Abductor force and joint force were smaller in the Chiari group, although long operative time, more blood loss, and verticalization of joint force were noted in this group. This limited study suggested that Chiari pelvic osteotomy changed the biomechanical features of the hip joint, and that this alteration might have compromised subsequent total hip arthroplasty.

A patterned microtexture to reduce friction and increase longevity of prosthetic hip joints

PubMed Central

Chyr, Anthony; Qiu, Mingfeng; Speltz, Jared; Jacobsen, Ronald L.; Sanders, Anthony P.; Raeymaekers, Bart

2014-01-01

More than 285,000 total hip replacement surgeries are performed in the US each year. Most prosthetic hip joints consist of a cobalt-chromium (CoCr) femoral head that articulates with a polyethylene acetabular component, lubricated with synovial fluid. The statistical survivorship of these metal-on-polyethylene prosthetic hip joints declines significantly after 10 to 15 years of use, primarily as a result of polyethylene wear and wear debris incited disease. The current engineering paradigm to increase the longevity of prosthetic hip joints is to improve the mechanical properties of the polyethylene component, and to manufacture ultra-smooth articulating surfaces. In contrast, we show that adding a patterned microtexture to the ultra-smooth CoCr femoral head reduces friction when articulating with the polyethylene acetabular liner. The microtexture increases the load-carrying capacity and the thickness of the joint lubricant film, which reduces contact between the articulating surfaces. As a result, friction and wear is reduced. We have used a lubrication model to design the geometry of the patterned microtexture, and experimentally demonstrate reduced friction for the microtextured compared to conventional smooth surrogate prosthetic hip joints. PMID:25013240

Pelvic incidence: a predictive factor for three-dimensional acetabular orientation-a preliminary study.

PubMed

Boulay, Christophe; Bollini, Gérard; Legaye, Jean; Tardieu, Christine; Prat-Pradal, Dominique; Chabrol, Brigitte; Jouve, Jean-Luc; Duval-Beaupère, Ginette; Pélissier, Jacques

2014-01-01

Acetabular cup orientation (inclination and anteversion) is a fundamental topic in orthopaedics and depends on pelvis tilt (positional parameter) emphasising the notion of a safe range of pelvis tilt. The hypothesis was that pelvic incidence (morphologic parameter) could yield a more accurate and reliable assessment than pelvis tilt. The aim was to find out a predictive equation of acetabular 3D orientation parameters which were determined by pelvic incidence to include in the model. The second aim was to consider the asymmetry between the right and left acetabulae. Twelve pelvic anatomic specimens were measured with an electromagnetic Fastrak system (Polhemus Society) providing 3D position of anatomical landmarks to allow measurement of acetabular and pelvic parameters. Acetabulum and pelvis data were correlated by a Spearman matrix. A robust linear regression analysis provided prediction of acetabulum axes. The orientation of each acetabulum could be predicted by the incidence. The incidence is correlated with the morphology of acetabula. The asymmetry of the acetabular roof was correlated with pelvic incidence. This study allowed analysis of relationships of acetabular orientation and pelvic incidence. Pelvic incidence (morphologic parameter) could determine the safe range of pelvis tilt (positional parameter) for an individual and not a group.

Pelvic Incidence: A Predictive Factor for Three-Dimensional Acetabular Orientation—A Preliminary Study

PubMed Central

Bollini, Gérard; Legaye, Jean; Tardieu, Christine; Prat-Pradal, Dominique; Chabrol, Brigitte; Jouve, Jean-Luc; Duval-Beaupère, Ginette; Pélissier, Jacques

2014-01-01

Acetabular cup orientation (inclination and anteversion) is a fundamental topic in orthopaedics and depends on pelvis tilt (positional parameter) emphasising the notion of a safe range of pelvis tilt. The hypothesis was that pelvic incidence (morphologic parameter) could yield a more accurate and reliable assessment than pelvis tilt. The aim was to find out a predictive equation of acetabular 3D orientation parameters which were determined by pelvic incidence to include in the model. The second aim was to consider the asymmetry between the right and left acetabulae. Twelve pelvic anatomic specimens were measured with an electromagnetic Fastrak system (Polhemus Society) providing 3D position of anatomical landmarks to allow measurement of acetabular and pelvic parameters. Acetabulum and pelvis data were correlated by a Spearman matrix. A robust linear regression analysis provided prediction of acetabulum axes. The orientation of each acetabulum could be predicted by the incidence. The incidence is correlated with the morphology of acetabula. The asymmetry of the acetabular roof was correlated with pelvic incidence. This study allowed analysis of relationships of acetabular orientation and pelvic incidence. Pelvic incidence (morphologic parameter) could determine the safe range of pelvis tilt (positional parameter) for an individual and not a group. PMID:25006461

Press-fit acetabular cup fixation: principles and testing.

PubMed

Macdonald, W; Carlsson, L V; Charnley, G J; Jacobsson, C M

1999-01-01

Pre-clinical testing of the fixation of press-fit acetabular components of total hip prostheses relies on cadaver or synthetic bone, but the properties and geometry of bone models differ from those of physiological bone. Cup designs use varied mechanisms for initial stability in bone; therefore, using different analogues and tests is appropriate. Press-fit cup stability was tested in the following: firstly, polyurethane (PU) foam modelling cancellous support; secondly, glass-fibre reinforced epoxide (GFRE) tubes modelling acetabular cortical support; thirdly, cadaveric acetabula. Three commercial cups [Harris-Galante II (H-G-II), Zimmer; Optifix, Smith & Nephew, Richards; porous coated anatomic (PCA), Howmedica] and an experimental cup with enhanced rim fixation were tested in three modes: direct pull-out, lever-out and axial torque. The fixation stabilities measured in the PU and the GFRE models showed trends consistent with those in cadaver bone, differing in the oversizing and cup geometry. The experimental cup was significantly more secure in most modes than other cups; the H-G II and Optifix cups showed similar stabilities, lower than that of the experimental cup but greater than that of the PCA cup (analysis of variance and Tukey's highly significant test; p < 0.001). The stabilities measured in cadaver bone more closely approximated those in GFRE. The use of several bone analogues enables separation of fixation mechanisms, allowing more accurate prediction of in vivo performance.

Accelerated aging, natural aging, and small punch testing of gamma-air sterilized polycarbonate urethane acetabular components.

PubMed

Kurtz, S M; Siskey, R; Reitman, M

2010-05-01

The objectives of this study were three-fold: (1) to determine the applicability of the small punch test to characterize Bionate 80A polycarbonate urethane (PCU) acetabular implants; (2) to evaluate the susceptibility of PCU acetabular implants to exhibit degradation of mechanical behavior following gamma irradiation in air and accelerated aging; and (3) to compare the oxidation of gamma-air sterilized PCU following accelerated aging and 5 years of natural shelf aging. In addition to attenuated total reflectance-Fourier transform infrared spectroscopy, we also adapted a miniature specimen mechanical test, the small punch test, for the deformable PCU cups. Accelerated aging was performed using ASTM F2003, a standard test that represents a severe oxidative challenge. The results of this study suggest that the small punch test is sufficiently sensitive and reproducible to discriminate slight differences in the large-deformation mechanical behavior of Bionate 80A following accelerated aging. The gamma-air sterilized PCU had a reduction of 9% in ultimate load after aging. Five years of shelf aging had little effect on the mechanical properties of the PCU. Overall, our findings suggest that the Bionate 80A material has greater oxidative stability than ultra-high molecular weight polyethylene following gamma irradiation in air and exposure to a severe oxidative challenge. (c) 2010 Wiley Periodicals, Inc.

The cost analysis of cemented versus cementless total hip replacement operations on the NHS.

PubMed

Kallala, R; Anderson, P; Morris, S; Haddad, F S

2013-07-01

In a time of limited resources, the debate continues over which types of hip prosthesis are clinically superior and more cost-effective. Orthopaedic surgeons increasingly need robust economic evidence to understand the full value of the operation, and to aid decision making on the 'package' of procedures that are available and to justify their practice beyond traditional clinical preference. In this paper we explore the current economic debate about the merits of cemented and cementless total hip replacement, an issue that continues to divide the orthopaedic community.

Acetabular cartilage defects cause altered hip and knee joint coordination variability during gait.

PubMed

Samaan, Michael A; Teng, Hsiang-Ling; Kumar, Deepak; Lee, Sonia; Link, Thomas M; Majumdar, Sharmila; Souza, Richard B

2015-12-01

Patients with acetabular cartilage defects reported increased pain and disability compared to those without acetabular cartilage defects. The specific effects of acetabular cartilage defects on lower extremity coordination patterns are unclear. The purpose of this study was to determine hip and knee joint coordination variability during gait in those with and without acetabular cartilage defects. A combined approach, consisting of a semi-quantitative MRI-based quantification method and vector coding, was used to assess hip and knee joint coordination variability during gait in those with and without acetabular cartilage lesions. The coordination variability of the hip flexion-extension/knee rotation, hip abduction-adduction/knee rotation, and hip rotation/knee rotation joint couplings were reduced in the acetabular lesion group compared to the control group during loading response of the gait cycle. The lesion group demonstrated increased variability in the hip flexion-extension/knee rotation and hip abduction-adduction/knee rotation joint couplings, compared to the control group, during the terminal stance/pre-swing phase of gait. Reduced variability during loading response in the lesion group may suggest reduced movement strategies and a possible compensation mechanism for lower extremity instability during this phase of the gait cycle. During terminal stance/pre-swing, a larger variability in the lesion group may suggest increased movement strategies and represent a compensation or pain avoidance mechanism caused by the load applied to the hip joint. Copyright © 2015 Elsevier Ltd. All rights reserved.

Does a cemented cage improve revision THA for severe acetabular defects?

PubMed

Hansen, Erik; Shearer, David; Ries, Michael D

2011-02-01

Evidence suggests a growing incidence of revision total hip arthroplasty (THA) including a subset with large acetabular defects. Revision THA for severe acetabular bone loss is associated with a relatively high rate of mechanical failure. We questioned whether cementing a cage to the reconstructed acetabular defect and pelvis would improve the rate of mechanical failure for patients with Type 3 defects (Paprosky et al.) with and without pelvic discontinuity in comparison to historical controls. We retrospectively collected data on 33 patients who underwent 35 revision THAs using an acetabular reconstruction cage cemented to morselized allograft and either structural allograft or trabecular metal augmentation for Type 3 defects in the presence (n = 13) and absence (n = 22) of pelvic discontinuity at a mean followup of 59 months (range, 24-92 months). The primary outcome was mechanical failure, defined as revision of the acetabular reconstruction for aseptic loosening. Revision surgery for mechanical failure occurred in four of the 13 patients with pelvic discontinuity and two of the 22 patients without discontinuity. Radiographic loosening occurred in one patient with and one patient without pelvic discontinuity. Seven of the 35 revisions were subsequently revised for deep infection all in patients who were immunocompromised. Cementing the cage to the pelvis can offer an advantage for treating severe acetabular defects. Trabecular metal augmentation appears to provide better initial mechanical stability than a structural allograft, but successful allograft reconstruction may restore bone stock. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Cementless Total Knee Arthroplasty in Patients Older Than 75 Years.

PubMed

Newman, Jared M; Khlopas, Anton; Chughtai, Morad; Gwam, Chukwuweike U; Mistry, Jaydev B; Yakubek, George A; Harwin, Steven F; Mont, Michael A

2017-11-01

Some surgeons have been hesitant to use cementless fixation for total knee arthroplasty (TKA) in elderly patients due to concerns regarding successful bone biological fixation. Therefore, this study evaluated: (1) implant survivorship, (2) functional outcomes, (3) radiographic outcomes, and (4) complications in patients over 75 years of age who underwent cementless total knee arthroplasty. A total of 134 patients (142 TKAs) older than 75 years at a single institution between June 2008 and June 2014 were retrospectively reviewed. Their mean follow-up was 4 years (range: 2-8 years). The cohort consisted of 91 women and 43 men who had a mean age of 80 years (range: 76 to 88 years). The preoperative diagnoses were osteoarthritis ( n  = 107 patients), rheumatoid arthritis ( n  = 21 patients), and osteonecrosis ( n  = 6 patients). Descriptive statistics were used to calculate the means and ranges and a Kaplan-Meier analysis was performed to determine the aseptic and all cause implant survivorship. Radiographic evaluation was performed using the new Knee Society Radiographic Evaluation and Scoring System. Functional outcomes at the final follow-up as well as all medical and surgical complications were recorded for each patient. The aseptic implant survivorship was 99.3% (95% CI: 7.9-8.1), and the all cause implant survivorship was 98.6% (95% CI: 7.9-8.1). There was one aseptic revision and one septic revision. At the latest follow-up the mean Knee Society pain score was 93 points (range, 80-100 points), and the mean Knee Society function score was 84 points (range, 70-90 points). On radiographic evaluation, there were no progressive radiolucencies, subsidence, and loosening of prostheses at the latest follow-up. The use of cementless TKA demonstrated excellent survivorship, mid-term clinical and functional outcomes, as well as no progressive radiolucencies or subsidence in patients older than 75 years. In addition, there was a low rate of surgical and medical complications. Therefore, cementless TKA may be a good option for patients older than 75 years. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Fixation of Trochanteric Fragments in Cementless Bipolar Hemiarthroplasty of Unstable Intertrochanteric Fracture: Cerclage Wiring

PubMed Central

Lee, Young-Kyun; Koo, Kyung-Hoi

2017-01-01

Purpose Bipolar hemiarthroplasty (HA) is an option for the treatment of unstable intertrochanteric fracture in elderly patients. There is a raising concern regarding cable-grip related complications for the fixation of trochanteric fragments. Therefore, the aim of this study was to evaluate outcome of cementless HA with fixation for the trochanteric fragments using monofilament wires in unstable intertrochanteric fracture. Materials and Methods We reviewed 92 cementless bipolar HAs using a grit-blasted long stem design for unstable intertrochanteric fractures in 91 elderly patients with a mean age of 81.7 years. During the arthroplasty, trochanteric fracture fragments were fixed using 1 or 2 vertical wires and transverse wires. We evaluated the clinical outcomes such as abductor power, ambulatory ability and wire-related complications, and radiologic outcomes including the union of the trochanteric fragment and subsidence of stem. Results Sixty-two patients were followed for a minimum of 2 years (mean, 59 months) postoperatively. The mean abductor power and Koval category was 4.1 (range, 3 to 5) and 4.6 (range, 1 to 6). The wire was broken in 3 hips (4.8%) and the nonunion of the greater trochanter occurred in 1 hips (1.6%). Two stems subsided by 3 mm and 8 mm, respectively, during postoperative 6 weeks, after which the subsidence was not progressive. Conclusion Cerclage wiring of the trochanter using monofilament wire leads to acceptable outcome in cementless HA for senile patients with unstable intertrochanteric fracture. Cerclage wiring using a monofilament wire is recommended for the fixation of trochanteric fragments. PMID:29250501

Nonsurgical Treatment of Acetabular Labral Tears.

PubMed

Theige, Melissa; David, Shannon

2018-05-04

Clinical Scenario: Surgical treatment of acetabular labral tears has been explored in multiple studies, while there is a lack of research on the effectiveness of conservative methods. Focused Clinical Question: To what extent can nonsurgical treatment produce symptomatic or functional improvements in athletes with an acetabular labral tear? Summary of Search, Best Evidence Appraised, and Key Findings: The literature was searched for studies of patients with confirmed acetabular labral tears who participated in any level of sport. Four studies were located, all of which were included. Clinical Bottom Line: The research discussed in this review agreed that conservative management of acetabular labral tears produced measurable improvements in pain and function among the athletes studied, including their ability to participate in sport activities. Based on these findings, it appears that conservative management is effective at rehabilitating athletes with acetabular labral tears. However, this method should not be applied to every athlete based on the low strength of current research. Treatment plans should be decided upon on a case-by-case basis. Strength of Recommendation: The studies located were of low quality. The highest Oxford Center for Evidence-Based Medicine Level of Evidence achieved was 4. Higher level studies must be conducted before the conclusions of this research can be applied clinically with assertion. Strength of recommendation is level 3.

Intraoperative CT in the assessment of posterior wall acetabular fracture stability.

PubMed

Cunningham, Brian; Jackson, Kelly; Ortega, Gil

2014-04-01

Posterior wall acetabular fractures that involve 10% to 40% of the posterior wall may or may not require an open reduction and internal fixation. Dynamic stress examination of the acetabular fracture under fluoroscopy has been used as an intraoperative method to assess joint stability. The aim of this study was to demonstrate the value of intraoperative ISO computed tomography (CT) examination using the Siemens ISO-C imaging system (Siemens Corp, Malvern, Pennsylvania) in the assessment of posterior wall acetabular fracture stability during stress examination under anesthesia. In 5 posterior wall acetabular fractures, standard fluoroscopic images (including anteroposterior pelvis and Judet radiographs) with dynamic stress examinations were compared with the ISO-C CT imaging system to assess posterior wall fracture stability during stress examination. After review of standard intraoperative fluoroscopic images under dynamic stress examination, all 5 cases appeared to demonstrate posterior wall stability; however, when the intraoperative images from the ISO-C CT imaging system demonstrated that 1 case showed fracture instability of the posterior wall segment during stress examination, open reduction and internal fixation was performed. The use of intraoperative ISO CT imaging has shown an initial improvement in the surgeon's ability to assess the intraoperative stability of posterior wall acetabular fractures during stress examination when compared with standard fluoroscopic images. Copyright 2014, SLACK Incorporated.

Promising Mid-term Results With a Cup-cage Construct for Large Acetabular Defects and Pelvic Discontinuity.

PubMed

Amenabar, Tomas; Rahman, Wael A; Hetaimish, Bandar M; Kuzyk, Paul R; Safir, Oleg A; Gross, Allan E

2016-02-01

Restoring normal anatomy and achieving stable fixation of the acetabular component can be especially challenging when the surgeon must deal with severe acetabular defects and/or pelvic discontinuity. The cup-cage (CC) construct, where an ilioischial cage is cemented within a biologically fixed porous metal cup, has emerged as an excellent option to treat such challenges. We sought to determine (1) mid-term Kaplan-Meier survival; (2) clinical outcomes based on Merle d'Aubigné-Postel scores; (3) radiological outcomes based primarily on construct migration; and (4) the complication rate for a series of 67 CC procedures performed at our institution. All hip revision procedures between January 2003 and March 2012 where a CC was used (with the exception of tumor cases or acute fracture; four total cases) that had a minimum 2-year followup and that had been seen within the last 2 years were included in this retrospective review. Acetabular bone loss and presence of pelvic discontinuity were assessed according to the Gross classification. Sixty-seven CC procedures with an average followup of 74 months (range, 24-135 months; SD, 34.3) months were identified; 26 of 67 (39%) were Gross Type IV and 41 of 67 (61%) were Gross Type V (pelvic discontinuity). Postoperative clinical and radiological evaluation was done annually. Merle d'Aubigné-Postel scores were recorded and all radiographs were compared with the 6-week postoperative radiographs to evaluate for radiographic loosening or migration. Failure was defined as revision surgery for any cause, including infection. The 5-year Kaplan-Meier survival rate with revision for any cause representing failure was 93% (95% confidence interval [CI], 83.1-97.4), and the 10-year survival rate was 85% (95% CI, 67.2-93.8). The Merle d'Aubigné-Postel score improved significantly from a mean of 6 preoperatively to 13 postoperatively (p < 0.001). Four CC had nonprogressive radiological migration of the ischial flange and they remain stable. We believe that the CC construct is a suitable choice to treat chronic pelvic discontinuity; it also remains a reliable option for the treatment of severe acetabular bone defects if stable fixation cannot be obtained through the use of a trabecular metal cup with or without augments. Level IV, therapeutic study.

A Pilot Study of Augmented Reality Technology Applied to the Acetabular Cup Placement During Total Hip Arthroplasty.

PubMed

Ogawa, Hiroyuki; Hasegawa, Seiichirou; Tsukada, Sachiyuki; Matsubara, Masaaki

2018-06-01

We developed an acetabular cup placement device, the AR-HIP system, using augmented reality (AR). The AR-HIP system allows the surgeon to view an acetabular cup image superimposed in the surgical field through a smartphone. The smartphone also shows the placement angle of the acetabular cup. This preliminary study was performed to assess the accuracy of the AR-HIP system for acetabular cup placement during total hip arthroplasty (THA). We prospectively measured the placement angles using both a goniometer and AR-HIP system in 56 hips of 54 patients undergoing primary THA. We randomly determined the order of intraoperative measurement using the 2 devices. At 3 months after THA, the placement angle of the acetabular cup was measured on computed tomography images. The primary outcome was the absolute value of the difference between intraoperative and postoperative computed tomography measurements. The measurement angle using AR-HIP was significantly more accurate in terms of radiographic anteversion than that using a goniometer (2.7° vs 6.8°, respectively; mean difference 4.1°; 95% confidence interval, 3.0-5.2; P < .0001). There was no statistically significant difference in terms of radiographic inclination (2.1° vs 2.6°; mean difference 0.5°; 95% confidence interval, -1.1 to 0.1; P = .13). In this pilot study, the AR-HIP system provided more accurate information regarding acetabular cup placement angle than the conventional method. Further studies are required to confirm the utility of the AR-HIP system as a navigation tool. Copyright © 2018 Elsevier Inc. All rights reserved.

Does the optimal position of the acetabular fragment should be within the radiological normal range for all developmental dysplasia of the hip? A patient-specific finite element analysis.

PubMed

Wang, Xuyi; Peng, Jianping; Li, De; Zhang, Linlin; Wang, Hui; Jiang, Leisheng; Chen, Xiaodong

2016-10-04

The success of Bernese periacetabular osteotomy depends significantly on how extent the acetabular fragment can be corrected to its optimal position. This study was undertaken to investigate whether correcting the acetabular fragment into the so-called radiological "normal" range is the best choice for all developmental dysplasia of the hip with different severities of dysplasia from the biomechanical view? If not, is there any correlation between the biomechanically optimal position of the acetabular fragment and the severity of dysplasia? Four finite element models with different severities of dysplasia were developed. The virtual periacetabular osteotomy was performed with the acetabular fragment rotated anterolaterally to incremental center-edge angles; then, the contact area and pressure and von Mises stress in the cartilage were calculated at different correction angles. The optimal position of the acetabular fragment for patients 1, 2, and 3 was when the acetabular fragment rotated 17° laterally (with the lateral center-edge angle of 36° and anterior center-edge angle of 58°; both were slightly larger than the "normal" range), 25° laterally following further 5° anterior rotation (with the lateral center-edge angle of 31° and anterior center-edge angle of 51°; both were within the "normal" range), and 30° laterally following further 10° anterior rotation (with the lateral center-edge angle of 25° and anterior center-edge angle of 40°; both were less than the "normal" range), respectively. The optimal corrective position of the acetabular fragment is severity dependent rather than within the radiological "normal" range for developmental dysplasia of the hip. We prudently proposed that the optimal correction center-edge angle of mild, moderate, and severe developmental dysplasia of the hip is slightly larger than the "normal" range, within the "normal" range, and less than the lower limit of the "normal" range, respectively.

Ten-Year Outcome of Serum Metal Ion Levels After Primary Total Hip Arthroplasty

PubMed Central

Levine, Brett R.; Hsu, Andrew R.; Skipor, Anastasia K.; Hallab, Nadim J.; Paprosky, Wayne G.; Galante, Jorge O.; Jacobs, Joshua J.

2013-01-01

Abstract: We previously reported on the metal ion concentrations of cobalt, chromium, and titanium that were found in the serum of patients three years after they had undergone primary total hip arthroplasty as compared with the concentrations found in the serum of control patients who did not have an implant. This study is a concise update on the serum metal levels found in a cohort of these patients ten years after the time of hip implantation. Of the original seventy-five subjects, metal ion levels were available for forty patients (53%). Ten patients (hybrid group) had received a hybrid total hip replacement that consisted of a modular cobalt-alloy femoral stem with a cobalt-alloy femoral head that had been inserted with cement and a titanium acetabular socket that had been inserted without cement. Nine patients (cobalt-chromium [CoCr] group) had received an implant with an extensively porous-coated modular cobalt-alloy femoral stem and femoral head along with a titanium acetabular socket; the femoral and acetabular components had each been inserted without cement. Eight patients (titanium group) had undergone insertion of a proximally porous-coated modular titanium-alloy femoral stem with a cobalt-alloy femoral head and a titanium acetabular socket; the femoral and acetabular components had each been inserted without cement. Thirteen patients (control group) from the original control group of patients who had not received an implant served as control subjects. Serum metal levels were measured with use of high-resolution sector field inductively coupled plasma mass spectrometry. The hybrid total hip arthroplasty group had mean cobalt levels that were 3.2 times higher at 120 months than they were at baseline, and the cobalt levels in that group were significantly higher than those in the titanium total hip arthroplasty group at thirty-six, sixty, eighty-four, ninety-six, and 120 months (p < 0.01). The hybrid group had mean chromium levels that were 3.9 times higher at 120 months than they were at baseline, and the CoCr total hip arthroplasty group had chromium levels that were 3.6 times higher at 120 months than they were at baseline. The serum titanium levels were higher in the titanium group at all follow-up time intervals as compared with the levels in all other groups, and the level in the titanium group at 120 months was eighteen times higher than it was at baseline (p < 0.01). Patients with well-functioning primary metal-on-polyethylene total hip replacements had elevated serum metal levels for as many as ten years postoperatively. Furthermore, metal release at the modular femoral head-neck junctions, rather than passive dissolution from porous ingrowth surfaces, was likely the dominant source of serum cobalt and chromium. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence. PMID:23515985

Preoperative digital planning versus postoperative outcomes in total hip arthroplasty using a calcar-guided short stem: frequent valgization can be avoided.

PubMed

Kutzner, Karl Philipp; Pfeil, Joachim; Kovacevic, Mark Predrag

2017-07-01

Modern total hip arthroplasty is largely dependent on the successful preservation of hip geometry. Thus, a successful implementation of the preoperative planning is of great importance. The present study evaluates the accuracy of anatomic hip reconstruction predicted by 2D digital planning using a calcar-guided short stem of the newest generation. A calcar-guided short stem was implanted in 109 patients in combination with a cementless cup using the modified anterolateral approach. Preoperative digital planning was performed including implant size, caput-collum-diaphyseal angle, offset, and leg length using mediCAD II software. A coordinate system and individual scale factors were implemented. Postoperative outcome was evaluated accordingly and was compared to the planning. Intraoperatively used stem sizes were within one unit of the planned stem sizes. The postoperative stem alignment showed a minor and insignificant (p = 0.159) mean valgization of 0.5° (SD 3.79°) compared to the planned caput-collum-diaphyseal angles. Compared to the planning, mean femoral offset gained 2.18 (SD 4.24) mm, while acetabular offset was reduced by 0.78 (SD 4.36) mm during implantation resulting in an increased global offset of 1.40 (SD 5.51) mm (p = 0.0094). Postoperative femoroacetabular height increased by a mean of 5.00 (SD 5.98) mm (p < 0.0001) compared to preoperative measures. Two-dimensional digital preoperative planning in calcar-guided short-stem total hip arthroplasty assures a satisfying implementation of the intended anatomy. Valgization, which has been frequently observed in previous short-stem designs, negatively affecting offset, can be avoided. However, surgeons have to be aware of a possible leg lengthening.

Safe surgical technique for associated acetabular fractures

PubMed Central

2013-01-01

Associated acetabular fractures are challenging injuries to manage. The complex surgical approaches and the technical difficulty in achieving anatomical reduction imply that the learning curve to achieve high-quality care of patients with such challenging injuries is extremely steep. This first article in the Journal’s “Safe Surgical Technique” section presents the standard surgical care, in conjunction with intraoperative tips and tricks, for the safe management of all subgroups of associated acetabular fractures. PMID:23414782

[APPLICATION AND EFFECTIVENESS OF BIOLOGICAL TYPE ACETABULAR CUP IN ADULT Crowe TYPE IV DEVELOPMENTAL DYSPLASIA OF THE HIP].

PubMed

Xu, Ning; Sun, Junying; Zhao, Xijiang; Wang, Tao

2016-01-01

To investigate the application and effectiveness of the biological type acetabular cup(diameter < 44 mm) in adult Crowe type IV developmental dysplasia of the hip (DDH). Between April 2001 andAugust 2013, biological type acetabular cup was used in total hip arthroplasty for the treatment of Crowe type IV DDH in16 cases (20 hips). There were 3 males and 13 females, aged 31-69 years (mean, 49 years). Unilateral hip was involved in 12cases, and bilateral hips in 4 cases. The patients showed pain of the hip joint and inequality of lower limb (shortening ofaffected limb 1.8-6.0 cm in length, 3.5 cm on average). Acetabular deformity, the relationship and the severity of femoralhead dislocation were comfirmed on the X-ray films. The preoperative Harris score was 34.0 ± 6.9. All patientsachieved healing of incision by first intention, with no complication of infection or neurovascular injury. Sixteen caseswere followed up 4-12 years (mean, 7.5 years). At 2 weeks after operation, dislocation occurred in 2 cases, and were fixedwith plaster for 3 weeks after reduction of the hip. Postoperative X-ray films showed complete reduction of femoral head;the average acetabular coverage of the cup of the weight-bearing area was 98.5% (range, 98.2%-99.1%). The cup from theRanawat triangle was 4.6-7.0 mm (mean, 5.8 mm) in medial shifting, and was 4.5-7.9 mm (mean, 6.2 mm) in elevation,it located at cup lateral surface area inside the iliopectineal line and the Kohler line (< 40%); the cup abduction angle was(45 ± 5)degrees, and the anteversion angle was (10 ± 5)degrees. The other patients had no prosthesis loosening except 1 patient havingextensive acetabular prosthesis loosening because of acetabular osteolysis at 12 years after operation. The hip Harris scorewas significantly improved to 85.0 ± 7.5 at 1 year after operation (t = 14.34, P = 0.01). The acetabular grindingprocess to retain enough bone combined with a small cup of-biological prosthesis treating adult Crowe type IV DDH has theadvantages of satisfactory coverage and initial acetabular fixation, so good early and mid-term effectiveness can be obtained.

Better early functional outcome after short stem total hip arthroplasty? A prospective blinded randomised controlled multicentre trial comparing the Collum Femoris Preserving stem with a Zweymuller straight cementless stem total hip replacement for the treatment of primary osteoarthritis of the hip

PubMed Central

van Oldenrijk, Jakob; Scholtes, Vanessa A B; van Beers, Loes W A H; Geerdink, Carel H; Niers, Bob B A M; Runne, Wouter; Bhandari, Mohit; Poolman, Rudolf W

2017-01-01

Objectives Primary aim was to compare the functional results at 3 months and 2 years between short and conventional cementless stem total hip arthroplasty (THA). Secondary aim was to determine the feasibility of a double-blind implant-related trial. Design A prospective blinded randomised controlled multicentre trial in patients with osteoarthritis of the hip. All patients, research assistants, clinical assessors, investigators and data analysts were blinded to the type of prosthesis. Population: 150 patients between 18 and 70 years with osteoarthritis of the hip, 75 in the short stem and 75 in the conventional stem group. Mean age: 60 years (SD 7). Interventions: the Collum Femoris Preserving short stem versus the Zweymuller Alloclassic conventional stem. Main outcome measures The Dutch version of the Hip Disability and Osteoarthritis Outcome Score (HOOS). Secondary outcomes measures: Harris Hip Score, the Physical Component Scale of the SF12, the Timed Up and Go test, Pain and the EQ-5D. Feasibility outcomes: continued blinding, protocol adherence and follow-up success rate. Results No significant difference between the two groups. Mean HOOS total score in the short stem group increased 32.7 points from 36.6 (95% CI 32.9 to 40.2) preoperatively to 69.3 (95% CI 66.4 to 72.1) at 3 months follow-up. Mean HOOS total score in the conventional straight stem group increased 36.3 points from 37.1 (95% CI 33.9 to 40.3) preoperatively to 73.4 (95% CI 70.3 to 76.4) at 3 months follow-up. 91.2% of patients remained blinded at 2 years follow-up. Both protocol adherence and follow-up success rate were 98%. Conclusions Functional result at 3 months and 2 years after short stem THA is not superior to conventional cementless THA. There were more perioperative and postoperative complications in the short stem group. Direct comparison of two hip implants in a double-blinded randomised controlled trial is feasible. Trial registration number NTR1560. PMID:29042371

Clinical Biomechanics of Wear in Total Hip Arthroplasty

PubMed Central

Callaghan, John J; Pedersen, Douglas R; Johnston, Richard C; Brown, Thomas D

2003-01-01

Complementary clinical and laboratory studies were performed to identify variables associated with polyethylene wear following total hip replacement, and to elucidate the mechanisms responsible for accelerated wear in the total hip arthroplasty construct. Observational cohort studies were performed using a prospective clinical database of more than 4000 consecutive primary total hip arthroplasties performed by a single surgeon, to identify wear-related variables. These variables included head size, acetabular/femoral component impingement, and third body debris. Novel digital edge detection techniques were developed and employed to accurately measure wear, and to determine the relationships of head size and third body debris to acceleration of wear. A novel slidingdistance-coupled finite element model was formulated and employed to examine the mechanisms responsible for wear. The long-term cohort studies demonstrated smaller head sizes to be associated with less wear. Third body debris generated from cable fretting was associated with an increase in wear, osteolysis, and acetabular loosening, especially with larger head sizes. The sliding-distance-coupled finite element model replicated the wear rates occurring in vitro and in vivo, demonstrating the importance of sliding distance on polyethylene wear following total hip arthroplasty. It also demonstrated substantial increases in wear associated with femoral head scratching from third body debris. Further extension of the finite element formulation demonstrated the potential for acetabular component rim damage from impingement wear, and the enhanced potential for third body ingress to the bearing surface with larger head sizes. Edge detection wear measurement techniques demonstrated that early wear rates were predictive of long-term wear rates. These complementary clinical and laboratory investigations have provided insight into 1) the significance of sliding distance and physiologic loci of motion as contributing factors in minimizing wear, 2) the deleterious effects of third body particulates in accelerating wear, 3) the potential for, and factors related to, impingement wear, and 4) the potential advantages and compromises related to the use of larger head sizes in the bearing surface construct. PMID:14575243

Impaction grafted bone chip size effect on initial stability in an acetabular model: Mechanical evaluation.

PubMed

Holton, Colin; Bobak, Peter; Wilcox, Ruth; Jin, Zhongmin

2013-01-01

Acetabular bone defect reconstruction is an increasing problem for surgeons with patients undergoing complex primary or revision total hip replacement surgery. Impaction bone grafting is one technique that has favourable long-term clinical outcome results for patients who undergo this reconstruction method for acetabular bone defects. Creating initial mechanical stability of the impaction bone graft in this technique is known to be the key factor in achieving a favourable implant survival rate. Different sizes of bone chips were used in this technique to investigate if the size of bone chips used affected initial mechanical stability of a reconstructed acetabulum. Twenty acetabular models were created in total. Five control models were created with a cemented cup in a normal acetabulum. Then five models in three different groups of bone chip size were constructed. The three groups had an acetabular protrusion defect reconstructed using either; 2-4 mm(3), 10 mm(3) or 20 mm(3) bone chip size for impaction grafting reconstruction. The models underwent compression loading up to 9500 N and displacement within the acetabular model was measured indicating the initial mechanical stability. This study reveals that, although not statistically significant, the largest (20 mm(3)) bone chip size grafted models have an inferior maximum stiffness compared to the medium (10 mm(3)) bone chip size. Our study suggests that 10 mm(3) size of bone chips provide better initial mechanical stability compared to smaller or larger bone chips. We dismissed the previously held opinion that the biggest practically possible graft is best for acetabular bone graft impaction.

The influence of acetabular bone cracks in the press-fit hip replacement: Numerical and experimental analysis.

PubMed

Ramos, A; Duarte, R J; Relvas, C; Completo, A; Simões, J A

2013-07-01

The press-fit hip acetabular prosthesis implantation can cause crack formation in the thin regions surrounding the acetabular. As a consequence the presence of cracks in this region can lead to poor fixation and fibrous tissue formation. Numerical and experimental models of commercial press-fit hip replacements were developed to compare the behavior between the intact and implanted joints. Numerical models with an artificial crack and without crack were considered. The iliac and the femur were created through 3D geometry acquisition based on composite human replicas and 3D-Finite Element models were generated. The mechanical behavior was assessed numerically and experimentally considering the principal strains. The comparison between Finite Element model predictions and experimental measurements revealed a maximum difference of 9%. Similar distribution of the principal strains around the acetabular cavity was obtained for the intact and implanted models. When comparing the Von Mises stresses, it is possible to observe that the intact model is the one that presents the highest stress values in the entire acetabular cavity surface. The crack in the posterior side changes significantly the principal strain distribution, suggesting bone loss after hip replacement. Relatively to micromotions, these were higher on the superior side of the acetabular cavity and can change the implant stability and bone ingrowth. Copyright © 2013 Elsevier Ltd. All rights reserved.

Accuracy of templating the acetabular cup size in Total Hip Replacement using conventional acetate templates on digital radiographs.

PubMed

Krishnamoorthy, Vignesh P; Perumal, Rajamani; Daniel, Alfred J; Poonnoose, Pradeep M

2015-12-01

Templating of the acetabular cup size in Total Hip Replacement (THR) is normally done using conventional radiographs. As these are being replaced by digital radiographs, it has become essential to create a technique of templating using digital films. We describe a technique that involves templating the digital films using the universally available acetate templates for THR without the use of special software. Preoperative digital radiographs of the pelvis were taken with a 30 mm diameter spherical metal ball strapped over the greater trochanter. Using standard acetate templates provided by the implant company on magnified digital radiographs, the size of the metal ball (X mm) and acetabular cup (Y mm) were determined. The size of the acetabular cup to be implanted was estimated using the formula 30*Y/X. The estimated size was compared with the actual size of the cup used at surgery. Using this technique, it was possible to accurately predict the acetabular cup size in 28/40 (70%) of the hips. When the accuracy to within one size was considered, templating was correct in 90% (36/40). When assessed by two independent observers, there was good intra-observer and inter-observer reliability with intra-class correlation coefficient values greater than 0.8. It was possible to accurately and reliably predict the size of the acetabular cup, using acetate templates on digital films, without any digital templates.

A Novel Approach for Treatment of Acetabular Fractures

PubMed Central

Xue, Zichao; Qin, Hui; Ding, Haoliang; An, Zhiquan

2016-01-01

Background There is no single approach that provides adequate exposure for treatment of all types of acetabular fractures. We describe our experience with an easier, relatively less invasive pubic symphysis approach (PSA) for the treatment of acetabular fractures. Material/Methods Between March 2011 and March 2012, fifteen patients with acetabular fracture underwent surgery using the PSA technique. Fracture reduction and treatment outcomes were assessed by clinical and radiological examination. Operation time, intraoperative blood loss and postoperative complications were documented. Results Mean operative time was 222±78 minutes. Average blood loss was 993±361 mL. Anatomical reduction was achieved in all patients. Minimum follow-up period was 31 months. Postoperative hypoesthesia in the area of innervation of the lateral femoral cutaneous nerve was reported in one patient, with spontaneous recovery at one month after surgery. No complications were reported during the follow-up period. At the most recent follow up, clinical outcomes were graded as “excellent” in six patients, “good” in eight patients and “fair” in one patient based on the modified Merle d’Aubigné-Postel score. Conclusions PSA appears to be a timesaving and safe approach for treatment of acetabular fractures that affords good visual access and allows for excellent fracture reduction. Our preliminary results revealed a much lower incidence of complications than traditional approaches, suggesting PSA is an alternative for treatment of acetabular fractures. PMID:27734825

21 CFR 888.3358 - Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... substrates, beads of the same alloy, and in the case of Ti-6Al-4V substrates, fibers of commercially pure titanium or Ti-6Al-4V alloy. The porous coating has a volume porosity between 30 and 70 percent, an average... titanium-aluminum-vanadium (Ti-6Al-4V) alloy and an acetabular component composed of an ultra-high...

21 CFR 888.3358 - Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... substrates, beads of the same alloy, and in the case of Ti-6Al-4V substrates, fibers of commercially pure titanium or Ti-6Al-4V alloy. The porous coating has a volume porosity between 30 and 70 percent, an average... titanium-aluminum-vanadium (Ti-6Al-4V) alloy and an acetabular component composed of an ultra-high...

21 CFR 888.3358 - Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... substrates, beads of the same alloy, and in the case of Ti-6Al-4V substrates, fibers of commercially pure titanium or Ti-6Al-4V alloy. The porous coating has a volume porosity between 30 and 70 percent, an average... titanium-aluminum-vanadium (Ti-6Al-4V) alloy and an acetabular component composed of an ultra-high...

21 CFR 888.3358 - Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... substrates, beads of the same alloy, and in the case of Ti-6Al-4V substrates, fibers of commercially pure titanium or Ti-6Al-4V alloy. The porous coating has a volume porosity between 30 and 70 percent, an average... titanium-aluminum-vanadium (Ti-6Al-4V) alloy and an acetabular component composed of an ultra-high...

Biomechanical modeling of acetabular component polyethylene stresses, fracture risk, and wear rate following press-fit implantation.

PubMed

Ong, Kevin L; Rundell, Steve; Liepins, Imants; Laurent, Ryan; Markel, David; Kurtz, Steven M

2009-11-01

Press-fit implantation may result in acetabular component deformation between the ischial-ilial columns ("pinching"). The biomechanical and clinical consequences of liner pinching due to press-fit implantation have not been well studied. We compared the effects of pinching on the polyethylene fracture risk, potential wear rate, and stresses for two different thickness liners using computational methods. Line-to-line ("no pinch") reaming and 2 mm underreaming press fit ("pinch") conditions were examined for Trident cups with X3 polyethylene liner wall thicknesses of 5.9 mm (36E) and 3.8 mm (40E). Press-fit cup deformations were measured from a foam block configuration. A hybrid material model, calibrated to experimentally determined stress-strain behavior of sequentially annealed polyethylene, was applied to the computational model. Molecular chain stretch did not exceed the fracture threshold in any cases. Nominal shell pinch of 0.28 mm was estimated to increase the volumetric wear rate by 70% for both cups and peak contact stresses by 140 and 170% for the 5.9 and 3.8 mm-thick liners, respectively. Although pinching increases liner stresses, polyethylene fracture is highly unlikely, and the volumetric wear rates are likely to be low compared to conventional polyethylene. (c) 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Computer-assisted virtual preoperative planning in orthopedic surgery for acetabular fractures based on actual computed tomography data.

PubMed

Wang, Guang-Ye; Huang, Wen-Jun; Song, Qi; Qin, Yun-Tian; Liang, Jin-Feng

2016-12-01

Acetabular fractures have always been very challenging for orthopedic surgeons; therefore, appropriate preoperative evaluation and planning are particularly important. This study aimed to explore the application methods and clinical value of preoperative computer simulation (PCS) in treating pelvic and acetabular fractures. Spiral computed tomography (CT) was performed on 13 patients with pelvic and acetabular fractures, and Digital Imaging and Communications in Medicine (DICOM) data were then input into Mimics software to reconstruct three-dimensional (3D) models of actual pelvic and acetabular fractures for preoperative simulative reduction and fixation, and to simulate each surgical procedure. The times needed for virtual surgical modeling and reduction and fixation were also recorded. The average fracture-modeling time was 45 min (30-70 min), and the average time for bone reduction and fixation was 28 min (16-45 min). Among the surgical approaches planned for these 13 patients, 12 were finally adopted; 12 cases used the simulated surgical fixation, and only 1 case used a partial planned fixation method. PCS can provide accurate surgical plans and data support for actual surgeries.

Comprehension and reproducibility of the Judet and Letournel classification

PubMed Central

Polesello, Giancarlo Cavalli; Nunes, Marcus Aurelius Araujo; Azuaga, Thiago Leonardi; de Queiroz, Marcelo Cavalheiro; Honda, Emerson Kyoshi; Ono, Nelson Keiske

2012-01-01

Objective To evaluate the effectiveness of the method of radiographic interpretation of acetabular fractures, according to the classification of Judet and Letournel, used by a group of residents of Orthopedics at a university hospital. Methods We selected ten orthopedic residents, who were divided into two groups; one group received training in a methodology for the classification of acetabular fractures, which involves transposing the radiographic images to a graphic two-dimensional representation. We classified fifty cases of acetabular fracture on two separate occasions, and determined the intraobserver and interobserver agreement. Result The success rate was 16.2% (10-26%) for the trained group and 22.8% (10-36%) for the untrained group. The mean kappa coefficients for interobserver and intraobserver agreement in the trained group were 0.08 and 0.12, respectively, and for the untrained group, 0.14 and 0.29. Conclusion Training in the method of radiographic interpretation of acetabular fractures was not effective for assisting in the classification of acetabular fractures. Level of evidence I, Testing of previously developed diagnostic criteria on consecutive patients (with universally applied reference "gold" standard). PMID:24453583

The tridimensional geometry of the proximal femur should determine the design of cementless femoral stem in total hip arthroplasty.

PubMed

Wegrzyn, Julien; Roux, Jean-Paul; Loriau, Charlotte; Bonin, Nicolas; Pibarot, Vincent

2018-02-22

Using a cementless femoral stem in total hip arthroplasty (THA), optimal filling of the proximal femoral metaphyseal volume (PFMV) and restoration of the extramedullary proximal femoral (PF) parameters (i.e., femoral offset (FO), neck length (FNL), and head height (FHH)) constitute key goals for optimal hip biomechanics, functional outcome, and THA survivorship. However, almost 30% of mismatch between the PF anatomy and implant geometry of the most widely implanted non-modular cementless femoral stem has been demonstrated in a computed tomography scan (CT scan) study. Therefore, this anatomic study aimed to evaluate the relationship between the intra- and extramedullary PF parameters using tridimensional CT scan reconstructions. One hundred fifty-one CT scans of adult healthy hips were obtained from 151 male Caucasian patients (mean age = 66 ± 11 years) undergoing lower limb CT scan arteriography. Tridimensional PF reconstructions and parameter measurements were performed using a corrected PF coronal plane-defined by the femoral neck and diaphyseal canal longitudinal axes-to avoid influence of PF helitorsion and femoral neck version on extramedullary PF parameters. Independently of the femoral neck-shaft angle, the PFMV was significantly and positively correlated with the FO, FNL, and FHH (r = 0.407 to 0.420; p < 0.0001). This study emphasized that the tridimensional PF geometry measurement in the corrected coronal plane of the femoral neck can be useful to determine and optimize the design of a non-modular cementless femoral stem. Particularly, continuous homothetic size progression of the intra- and extramedullary PF parameters should be achieved to assure stem fixation and restore anatomic hip biomechanics.

Does cemented or cementless single-stage exchange arthroplasty of chronic periprosthetic hip infections provide similar infection rates to a two-stage? A systematic review.

PubMed

George, D A; Logoluso, N; Castellini, G; Gianola, S; Scarponi, S; Haddad, F S; Drago, L; Romano, C L

2016-10-10

The best surgical modality for treating chronic periprosthetic hip infections remains controversial, with a lack of randomised controlled studies. The aim of this systematic review is to compare the infection recurrence rate after a single-stage versus a two-stage exchange arthroplasty, and the rate of cemented versus cementless single-stage exchange arthroplasty for chronic periprosthetic hip infections. We searched for eligible studies published up to December 2015. Full text or abstract in English were reviewed. We included studies reporting the infection recurrence rate as the outcome of interest following single- or two-stage exchange arthroplasty, or both, with a minimum follow-up of 12 months. Two reviewers independently abstracted data and appraised quality assessment. After study selection, 90 observational studies were included. The majority of studies were focused on a two-stage hip exchange arthroplasty (65 %), 18 % on a single-stage exchange, and only a 17 % were comparative studies. There was no statistically significant difference between a single-stage versus a two-stage exchange in terms of recurrence of infection in controlled studies (pooled odds ratio of 1.37 [95 % CI = 0.68-2.74, I 2  = 45.5 %]). Similarly, the recurrence infection rate in cementless versus cemented single-stage hip exchanges failed to demonstrate a significant difference, due to the substantial heterogeneity among the studies. Despite the methodological limitations and the heterogeneity between single cohorts studies, if we considered only the available controlled studies no superiority was demonstrated between a single- and two-stage exchange at a minimum of 12 months follow-up. The overalapping of confidence intervals related to single-stage cementless and cemented hip exchanges, showed no superiority of either technique.

[Aseptic, simultaneous and bilateral mobilisation due to an acetabular shell fracture in a 43 year-old patient].

PubMed

Ceretti, M; Fanelli, M; Pappalardo, S

2014-01-01

The acetabular shell mobilization is the main long-term complication in total hip replacement. Metal-back fracture has also to be considered among the possible causes of shell mobilization. A case is presented of bilateral acetabular shell mobilization due to the trabecular covering de-soldering from the metal-back in a 43 year-old patient, 13-14 years after the first surgery. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

Can acetabular orientation be restored by lumbar pedicle subtraction osteotomy in ankylosing spondylitis patients with thoracolumbar kyphosis?

PubMed

Hu, Jun; Qian, Bang-Ping; Qiu, Yong; Wang, Bin; Yu, Yang; Zhu, Ze-Zhang; Jiang, Jun; Mao, Sai-Hu; Qu, Zhe; Zhang, Yun-Peng

2017-07-01

To evaluate whether acetabular orientation (abduction and anteversion) can be restored by lumbar pedicle subtraction osteotomy (PSO) in ankylosing spondylitis (AS) patients with thoracolumbar kyphosis. A total of 33 consecutive AS patients with thoracolumbar kyphosis undergoing one-level lumbar PSO were retrospectively reviewed. Radiographical measurements included sagittal vertical axis, global kyphosis, thoracic kyphosis, local kyphosis, lumbar lordosis, pelvic incidence, sacral slope, and pelvic tilt. Acetabular abduction and anteversion were measured on CT scans of the pelvis before and after lumbar PSO. The preoperative and postoperative parameters were compared by the paired samples t test. Pearson's correlation analysis was conducted to determine the correlations between the changes in acetabular abduction and anteversion and the changes in sagittal spinopelvic parameters. After lumbar PSO, sagittal vertical axis, global kyphosis, and pelvic tilt were corrected from 15.7 ± 6.7 cm, 66.8° ± 17.5°, and 38.6° ± 9.0° to 2.9 ± 4.9 cm, 21.3° ± 8.2°, and 23.2° ± 8.2°, respectively (p < 0.001). Of note, acetabular abduction and anteversion decreased from 59.6° ± 4.6° to 31.4° ± 6.5° before surgery to 51.4° ± 6.5° and 20.2° ± 4.4° after surgery, respectively (p < 0.001). Moreover, the changes in acetabular abduction and anteversion were observed significantly correlated with the change in pelvic tilt (r = 0.527, p = 0.002; r = 0.586, p < 0.001). Abnormal acetabular abduction and anteversion could be corrected by lumbar PSO in AS patients with thoracolumbar kyphosis. Consequently, a relatively normal acetabular orientation could be achieved after lumbar PSO, which might decrease the potential risk of dislocation in AS patients with spine and hip deformities requiring subsequent THR surgery.

Surface evaluation of orthopedic hip implants marketed in Brazil

NASA Astrophysics Data System (ADS)

Souza, M. M.; Trommer, R. M.; Maru, M. M.; Roesler, C. R. M.; Barros, W. S.; Dutra, M. S.

2016-07-01

One of the factors that contribute to the quality of total hip prostheses is the degree of accuracy in the manufacturing of the joint surfaces. The dimensional control of joint components is important because of its direct influence on the durability and, consequently, in the patients’ life quality. This work presents studies on the form and roughness of orthopedic hip prostheses marketed in Brazil. The results provide data for quality control of the surfaces of the femoral heads and acetabular components of hip prostheses and indicate the need of improvement in the procedures used to this control.

Inversion of the acetabular labrum triggers rapidly destructive osteoarthritis of the hip: representative case report and proposed etiology.

PubMed

Fukui, Kiyokazu; Kaneuji, Ayumi; Fukushima, Mana; Matsumoto, Tadami

2014-12-01

The pathophysiology of rapidly destructive osteoarthritis (OA) of the hip is unknown. This study documented cases of inversion of the acetabular labrum, which has clinicoradiologic features similar to those of initial-stage rapidly destructive hip OA. Our study was based on a prospective review of data for 9 patients with rapidly destructive hip OA. Intraoperative findings showed that the anterosuperior portion of the acetabular labrum had inverted into the articular space, along with many fragments of articular cartilage, in all patients. Subchondral insufficiency fractures of the femoral heads were seen just under the inverted labra in 8 of the 9 patients. Inversion of the acetabular labrum may be involved in rapid joint-space narrowing and subchondral insufficiency fracture in rapidly destructive hip OA. Copyright © 2014 Elsevier Inc. All rights reserved.

Acetabular rim and surface segmentation for hip surgery planning and dysplasia evaluation

NASA Astrophysics Data System (ADS)

Tan, Sovira; Yao, Jianhua; Yao, Lawrence; Summers, Ronald M.; Ward, Michael M.

2008-03-01

Knowledge of the acetabular rim and surface can be invaluable for hip surgery planning and dysplasia evaluation. The acetabular rim can also be used as a landmark for registration purposes. At the present time acetabular features are mostly extracted manually at great cost of time and human labor. Using a recent level set algorithm that can evolve on the surface of a 3D object represented by a triangular mesh we automatically extracted rims and surfaces of acetabulae. The level set is guided by curvature features on the mesh. It can segment portions of a surface that are bounded by a line of extremal curvature (ridgeline or crestline). The rim of the acetabulum is such an extremal curvature line. Our material consists of eight hemi-pelvis surfaces. The algorithm is initiated by putting a small circle (level set seed) at the center of the acetabular surface. Because this surface distinctively has the form of a cup we were able to use the Shape Index feature to automatically extract an approximate center. The circle then expands and deforms so as to take the shape of the acetabular rim. The results were visually inspected. Only minor errors were detected. The algorithm also proved to be robust. Seed placement was satisfactory for the eight hemi-pelvis surfaces without changing any parameters. For the level set evolution we were able to use a single set of parameters for seven out of eight surfaces.

[Quantification of acetabular coverage in normal adult].

PubMed

Lin, R M; Yang, C Y; Yu, C Y; Yang, C R; Chang, G L; Chou, Y L

1991-03-01

Quantification of acetabular coverage is important and can be expressed by superimposition of cartilage tracings on the maximum cross-sectional area of the femoral head. A practical Autolisp program on PC AutoCAD has been developed by us to quantify the acetabular coverage through numerical expression of the images of computed tomography. Thirty adults (60 hips) with normal center-edge angle and acetabular index in plain X ray were randomly selected for serial drops. These slices were prepared with a fixed coordination and in continuous sections of 5 mm in thickness. The contours of the cartilage of each section were digitized into a PC computer and processed by AutoCAD programs to quantify and characterize the acetabular coverage of normal and dysplastic adult hips. We found that a total coverage ratio of greater than 80%, an anterior coverage ratio of greater than 75% and a posterior coverage ratio of greater than 80% can be categorized in a normal group. Polar edge distance is a good indicator for the evaluation of preoperative and postoperative coverage conditions. For standardization and evaluation of acetabular coverage, the most suitable parameters are the total coverage ratio, anterior coverage ratio, posterior coverage ratio and polar edge distance. However, medial coverage and lateral coverage ratios are indispensable in cases of dysplastic hip because variations between them are so great that acetabuloplasty may be impossible. This program can also be used to classify precisely the type of dysplastic hip.

Magnetic resonance imaging with gadolinium arthrography to assess acetabular cartilage delamination.

PubMed

Zaragoza, Edward; Lattanzio, Pierre-Jean; Beaule, Paul E

2009-01-01

Recent reports have demonstrated magnetic resonance imaging (MRI) as a promising technique in detecting articular cartilage lesions of the hip joint. The purpose of our study was to evaluate the diagnostic performance of MRI with gadolinium arthrography in detecting acetabular cartilage delamination in patients with pre-arthritic hip pain. 46 patients (48 hips) underwent surgical dislocation of the hip. Mean age was 38.8 (range 17-56). There were 26 males and 20 females. All patients had Magnetic Resonance Imaging with gadolinium arthrography (MRA) before undergoing open hip surgery where the acetabular cartilage was inspected. Acetabular cartilage delamination on MRA was seen on sagittal images as a linear intra-articular filling defect of low signal intensity >1mm in thickness on T1 weighted images and surrounded by contrast. On MRA all hips had a labral tear confirmed at surgery. At surgery 30 hips had evidence of acetabular cartilage delamination, 4 hips had ulceration and 14 had no articular cartilage damage. The majority of labral tears and cartilage damage were located in the antero-superior quadrant. The sensitivity and specificity of MRA detection of cartilage delamination confirmed at surgery were 97% and 84%, respectively. The positive and negative predictive values of the MRA finding were 90% and 94%, respectively. The presence of the acetabular cartilage delamination represents an early stage of articular cartilage degeneration. When evaluating a young adult with hip pain, labral tears in association with cartilage delamination should be considered. MRA represents an effective diagnostic tool.

Acetabular labral tears in patients with sports injury.

PubMed

Kang, Chan; Hwang, Deuk-Soo; Cha, Soo-Min

2009-12-01

We wanted to investigate acetabular labral tears and their correlation with femoroacetabular impingement in patients with sports injury. Among 111 patients who were diagnosed with the acetabular labral tears after arthroscopic treatment from January 2004 to December 2007, we selected 41 patients with sports injury. There were 12 cases of Taekwondo injury, 5 of golf injury, 4 of soccer injury, 3 of gymnastics injury, 2 of Hapkido injury, 2 of aerobics injury, 2 of rock-climbing injury, 2 of fitness training injury and 9 of other sports injuries. We checked the subtypes of acetabular labral tears and the accompanying femoroacetabular impingement. For the cases with accompanying femoroacetabular impingement, we investigated the subtypes according to the types of sports, gender and age. At last follow-up, we checked the Harris Hip Score (HHS), the Hip Outcome Score (HOS) sports scale and the percentage of patients who returned to their sports activity. The average age of symptomatic onset was 26 years (range, 12 to 65 years). The ratio of males to females was 29 : 12. An average duration of the hip pain was 17 months (range, 1 to 60 months). The degenerative type of acetabular labral tears was the most prevalent with 32 cases (78%), and there were 9 cases (22%) of the partial tear type. Thirty cases (73%) were accompanied by femoroacetabular impingement. The average age of the 23 cases (56%) of the cam-type was 23 years (range, 12 to 48 years), and it was more likely to occur in men (87%) and for people practicing martial arts such as Taekwondo or Hapkido. An average age of the 5 cases (12%) of the pincer-type was 26 (range, 16 to 43 years), it usually occurred in women (60%) and for non-martial arts such as golf and gymnastics. There were 2 cases of the mixed type (cam + pincer-type). At 27 months follow-up, the HHS was 61 to 92 points, the HOS sports scale increased 43 to 75%, and the rate of returning to sports was 71%. In spite of the early expression of symptoms and the short duration of the acetabular labral tears, the high rate of degenerative acetabular labral tears in sports patients is likely associated with repetitive injury after the expression of symptoms. Femoroacetabular impingement in sports patients is seemed to be a cause of the early occurrence of acetabular labral tears. Because the possibility of acetabular labral tears is high in femoroacetabular impingement, sports patients may need to undergo early screening for the diagnosis and care of femoroacetabular impingement.

A new method for the measurement of anteversion of the acetabular cup after total hip arthroplasty.

PubMed

Aydogan, Mehmet; Burç, Halil; Saka, Gursel

2014-08-01

Many methods of determining the anteversion of the acetabular cup have been described in the literature. The advantages and disadvantages of each of these methods are discussed in this paper. We present a new method of measuring the acetabular anteversion at the anteroposterior hip. The formula designed by the authors was anteversion angle (α) = arc sin |PK|/√ |AK| × |BK|. The formula was tested using the AutoCAD software, and an experimental study was conducted to evaluate the accuracy. Three groups were created, and 16 X-ray images were taken and coded. Ten orthopaedic surgeons measured the acetabular anteversion from these X-rays using our formula. The results in Group 1 were closer to the actual value; in contrast, the results in Group 2 differed from the actual values. The results in Group 3 were as close to the actual anteversion values as were those in Group 1. Developments in technology often bring an increase in complications. Despite newly developed surgical methods and technology, the position of the acetabular cup is still used to determine the results of a total hip arthroplasty. Our method is simple, cost-effective and achieves almost 100 % accuracy.

Tribological characteristics of a composite total-surface hip replacement

NASA Technical Reports Server (NTRS)

Jones, W. R., Jr.; Roberts, J. C.; Ling, F. F.

1982-01-01

Continuous fiber, woven E glass composite femoral shells having the same elastic properties as bone were fabricated. The shells were then encrusted with filled epoxy wear resistant coatings and run dry against ultrahigh molecular weight polyethylene acetabular cups in 42,000 and 250,000 cycle wear tests on a total hip simulator. The tribological characteristics of these continuous fiber particulate composite femoral shells articulating with ultrahigh molecular weight polyethylene acetabular cups were comparable to those of a vitallium ball articulating with an ultrahigh molecular weight polyethylene acetabular cup.

Stabilization of an acetabular fracture with cables for acute total hip arthroplasty.

PubMed

Mears, D C; Shirahama, M

1998-01-01

A critical stage of total hip arthroplasty for an acute acetabular fracture where extensive comminution, impaction, and osteopenia thwart the application of conventional open or closed methods, especially in the elderly, is stable fixation of the acetabulum. The use of 2-mm braided cables permits effective immobilization of the fracture for use in conjunction with a hybrid arthroplasty. The method is consistent with the use of a conventional arthroplastic incision and is suitable for other applications including the fixation of periprosthetic fractures, bulk allografts, and conventional acetabular fractures.

Direct hip joint distraction during acetabular fracture surgery using the AO universal manipulator.

PubMed

Calafi, L Afshin; Routt, M L Chip

2010-02-01

Certain acetabular fractures may necessitate distraction of the hip joint for removal of intra-articular debris and assessment of reduction. Distraction can be accomplished by manual traction, using a traction table or an AO universal manipulator (UM). The UM is a relatively simple and an inexpensive device that can provide focal distraction in a controlled manner without the risks associated with the use of a traction table. We describe a technique using the UM for hip joint distraction during acetabular fracture surgery through a Kocher-Langenbeck surgical exposure.

The prevalence of acetabular anomalies associated with pistol-grip-deformity in osteoarthritic hips.

PubMed

Ipach, I; Mittag, F; Walter, C; Syha, R; Wolf, P; Kluba, T

2013-02-01

Acetabular retroversion, excessive acetabular coverage and abnormal head-neck-junction with a so-called "pistol-grip-deformity" were added to the classical description of hip dysplasia to describe pathological hip morphology. The aim of the current study was the detection of pathological acetabular geometry in patients with an abnormal head-neck-junction. Femoroacetabular impingement and hip dysplasia features are frequent in patients with end-stage osteoarthritis before 60 years of age. We analysed our data bank retrospectively for all patients who received a Total Hip Arthroplasty (THA) due to end-stage osteoarthritis before the age of 60 years. The pelvic-views and the Dunn-view of these patients were screened for an abnormal head-neck-junction by measuring the head-ratio and the alpha-angle. An orthopaedic surgeon and a radiologist did this independently. These radiographies were measured for signs of acetabular dysplasia, excessive acetabular coverage and crossing sign. A consecutive series of 135 total hip arthroplasties were performed in patients aged less or equal to 60 years because of end-stage osteoarthritis. From these, 81 patients were classified as having an abnormal head-neck-junction. The mean head-ratio in these 81 patients was 1.52±0.35, the mean alpha-angle was 62.5°±9.3°. The mean CE-angle of these 81 patients was 35.8°±10.4°, the mean CA-angle was 36.7°±5.7°, the mean depth-width ratio was 49.1±10, the mean extrusion index was 19.1±9.2 and the mean CCD-angle was 131.7°±7.3°. Of these 81hips, 14 had isolated pistol-grip-deformity, while 11 hips had associated dysplasia, 38 had excessive acetabular coverage, and 14 had crossing sign. In addition, a crossing sign was identified in four of the 11 dysplastic hips and 19 of the 38 of the hips having excessive acetabular coverage. There was no statistically significant difference in regard to the age between the four groups (P=0.087). In contrast, the hips that had excessive acetabular coverage had increased CE-angle (44.6°±7.2°) and decreased extrusion index (12.6±6.5) (P<0.001), while dysplastic hips had increased roof obliquity (17.5°±4.5°) and increased extrusion index (29.6±9.1), as well as decreased CE-angle (20.7°±3.0°) (P<0.001). There is a high coincidence of radiographic findings associated with an abnormal head-neck-junction consisting in excessive acetabular coverage and retroversion as well as hip dysplasia. These results advocate for restoring of the normal anatomy at the early stage to prevent end-stage osteoarthritis. Level IV retrospective historical study. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

[Effects of Surgically Treated Pelvic Ring and Acetabular Fractures on Postural Control].

PubMed

Lang, P; Schnegelberger, A; Riesner, H-J; Stuby, F; Friemert, B; Palm, H-G

2016-04-01

The aim of surgical treatment of pelvic ring and acetabular fractures is to allow rapid mobilisation of patients in order to restore stance and gait stability (postural control), as this significantly correlates with a positive outcome. The regulation of postural stability is mainly controlled by transmission of proprioceptive stimuli. In addition, the pelvis serves as a connection between the legs and the spine and thus is also of great importance for mechanical stabilisation. It remains unclear whether surgical treatment of pelvic ring and acetabular fractures affects the regulation of postural control. Therefore, the aim of this study was to examine the impact of surgically treated pelvic ring and acetabular fractures on postural stability by means of computerised dynamic posturography (CDP) after a mean of 35 months and to compare the results with a healthy control group. A retrospective case control study of 38 patients with surgically treated pelvic ring and acetabular fractures and 38 healthy volunteers was carried out using CDP. The average time of follow-up was 35 (12-78) months. The most important outcome parameter in this investigation was the overall stability index (OSI). Hip joint mobility, the health-related quality of life (SF-12) and pain were supplementary outcome parameters. It was found that surgically treated pelvic ring and acetabular fractures had no influence on postural stability. The OSI was 2.1 ° in the patient group and 1.9 ° in the control group. There was no significant difference between the groups in hip joint mobility. A total of 52 % of patients showed no or only mild pain. Mean health-related quality of life was the same as in the total population. Surgically treated pelvic ring and acetabular fractures do not lead to deterioration in postural control in the mid term. This is of high prognostic importance for rapid mobilisation of the patients. Therefore no increase in the risk of falling is expected after successfully treatment of fractures. Georg Thieme Verlag KG Stuttgart · New York.

A combination of three-dimensional printing and computer-assisted virtual surgical procedure for preoperative planning of acetabular fracture reduction.

PubMed

Zeng, Canjun; Xing, Weirong; Wu, Zhanglin; Huang, Huajun; Huang, Wenhua

2016-10-01

Treatment of acetabular fractures remains one of the most challenging tasks that orthopaedic surgeons face. An accurate assessment of the injuries and preoperative planning are essential for an excellent reduction. The purpose of this study was to evaluate the feasibility, accuracy and effectiveness of performing 3D printing technology and computer-assisted virtual surgical procedures for preoperative planning in acetabular fractures. We hypothesised that more accurate preoperative planning using 3D printing models will reduce the operation time and significantly improve the outcome of acetabular fracture repair. Ten patients with acetabular fractures were recruited prospectively and examined by CT scanning. A 3-D model of each acetabular fracture was reconstructed with MIMICS14.0 software from the DICOM file of the CT data. Bone fragments were moved and rotated to simulate fracture reduction and restore the pelvic integrity with virtual fixation. The computer-assisted 3D image of the reduced acetabula was printed for surgery simulation and plate pre-bending. The postoperative CT scan was performed to compare the consistency of the preoperative planning with the surgical implants by 3D-superimposition in MIMICS14.0, and evaluated by Matta's method. Computer-based pre-operations were precisely mimicked and consistent with the actual operations in all cases. The pre-bent fixation plates had an anatomical shape specifically fit to the individual pelvis without further bending or adjustment at the time of surgery and fracture reductions were significantly improved. Seven out of 10 patients had a displacement of fracture reduction of less than 1mm; 3 cases had a displacement of fracture reduction between 1 and 2mm. The 3D printing technology combined with virtual surgery for acetabular fractures is feasible, accurate, and effective leading to improved patient-specific preoperative planning and outcome of real surgery. The results provide useful technical tips in planning pelvic surgeries. Copyright © 2016 Elsevier Ltd. All rights reserved.

Does hemipelvis structure and position influence acetabulum orientation?

PubMed

Musielak, Bartosz; Jóźwiak, Marek; Rychlik, Michał; Chen, Brian Po-Jung; Idzior, Maciej; Grzegorzewski, Andrzej

2016-03-16

Although acetabulum orientation is well established anatomically and radiographically, its relation to the innominate bone has rarely been addressed. If explored, it could open the discussion on patomechanisms of such complex disorders as femoroacetabular impingement (FAI). We therefore evaluated the influence of pelvic bone position and structure on acetabular spatial orientation. We describe this relation and its clinical implications. This retrospective study was based on computed tomography scanning of three-dimensional models of 31 consecutive male pelvises (62 acetabulums). All measurements were based on CT spatial reconstruction with the use of highly specialized software (Rhinoceros). Relations between acetabular orientation (inclination, tilt, anteversion angles) and pelvic structure were evaluated. The following parameters were evaluated to assess the pelvic structure: iliac opening angle, iliac tilt angle, interspinous distance (ISD), intertuberous distance (ITD), height of the pelvis (HP), and the ISD/ITD/HP ratio. The linear and nonlinear dependence of the acetabular angles and hemipelvic measurements were examined with Pearson's product - moment correlation and Spearman's rank correlation coefficient. Correlations different from 0 with p < 0.05 were considered statistically significant. Comparison of the axis position with pelvis structure with orientation in the horizontal plane revealed a significant positive correlation between the acetabular anteversion angle and the iliac opening angle (p = 0.041 and 0.008, respectively). In the frontal plane, there was a positive correlation between the acetabular inclination angle and the iliac tilt angle (p = 0.025 and 0.014, respectively) and the acetabular inclination angle and the ISD/ITD/HP ratio (both p = 0.048). There is a significant correlation of the hemipelvic structure and acetabular orientation under anatomic conditions, especially in the frontal and horizontal planes. In the anteroposterior view, the more tilted-down innominate bone causes a more caudally oriented acetabulum axis, whereas in the horizontal view this relation is reversed. This study may serve as a basis for the discussion on the role of the pelvis in common disorders of the hip.

Analysis of acetabular orientation and femoral anteversion using images of three-dimensional reconstructed bone models.

PubMed

Park, Jaeyeong; Kim, Jun-Young; Kim, Hyun Deok; Kim, Young Cheol; Seo, Anna; Je, Minkyu; Mun, Jong Uk; Kim, Bia; Park, Il Hyung; Kim, Shin-Yoon

2017-05-01

Radiographic measurements using two-dimensional (2D) plain radiographs or planes from computed tomography (CT) scans have several drawbacks, while measurements using images of three-dimensional (3D) reconstructed bone models can provide more consistent anthropometric information. We compared the consistency of results using measurements based on images of 3D reconstructed bone models (3D measurements) with those using planes from CT scans (measurements using 2D slice images). Ninety-six of 561 patients who had undergone deep vein thrombosis-CT between January 2013 and November 2014 were randomly selected. We evaluated measurements using 2D slice images and 3D measurements. The images used for 3D reconstruction of bone models were obtained and measured using [Formula: see text] and [Formula: see text] (Materialize, Leuven, Belgium). The mean acetabular inclination, acetabular anteversion and femoral anteversion values on 2D slice images were 42.01[Formula: see text], 18.64[Formula: see text] and 14.44[Formula: see text], respectively, while those using images of 3D reconstructed bone models were 52.80[Formula: see text], 14.98[Formula: see text] and 17.26[Formula: see text]. Intra-rater reliabilities for acetabular inclination, acetabular anteversion, and femoral anteversion on 2D slice images were 0.55, 0.81, and 0.85, respectively, while those for 3D measurements were 0.98, 0.99, and 0.98. Inter-rater reliabilities for acetabular inclination, acetabular anteversion and femoral anteversion on 2D slice images were 0.48, 0.86, and 0.84, respectively, while those for 3D measurements were 0.97, 0.99, and 0.97. The differences between the two measurements are explained by the use of different tools. However, more consistent measurements were possible using the images of 3D reconstructed bone models. Therefore, 3D measurement can be a good alternative to measurement using 2D slice images.

Periacetabular osteotomy: a review of swiss experience.

PubMed

Büchler, Lorenz; Beck, Martin

2014-12-01

Symptomatic dysplasia of the hip and acetabular retroversion are possible causes of osteoarthritis in the young adult. Surgical management with reorientation of the acetabulum allows causal therapy of the deformity and preservation of the native hip joint. The Ganz' periacetabular osteotomy permits a free 3-dimensional reorientation of the acetabulum and respects the blood supply of the acetabular fragment. The posterior column remains intact with a stable fixation of the acetabular fragment and a preserved shape of the true pelvis. There is a significant learning curve with severe complications in up to 30 % of cases. Good results can be expected in the long-term follow-up if performed with correct indication at young age in hips with preserved joint cartilage and proper reorientation of the acetabular fragment. Overall survivorship is superior to the natural course of hip dysplasia with a preserved hip joint in 61 % after 20 years.

Adoption of Robotic vs Fluoroscopic Guidance in Total Hip Arthroplasty: Is Acetabular Positioning Improved in the Learning Curve?

PubMed

Kamara, Eli; Robinson, Jonathon; Bas, Marcel A; Rodriguez, Jose A; Hepinstall, Matthew S

2017-01-01

Acetabulum positioning affects dislocation rates, component impingement, bearing surface wear rates, and need for revision surgery. Novel techniques purport to improve the accuracy and precision of acetabular component position, but may have a significant learning curve. Our aim was to assess whether adopting robotic or fluoroscopic techniques improve acetabulum positioning compared to manual total hip arthroplasty (THA) during the learning curve. Three types of THAs were compared in this retrospective cohort: (1) the first 100 fluoroscopically guided direct anterior THAs (fluoroscopic anterior [FA]) done by a surgeon learning the anterior approach, (2) the first 100 robotic-assisted posterior THAs done by a surgeon learning robotic-assisted surgery (robotic posterior [RP]), and (3) the last 100 manual posterior (MP) THAs done by each surgeon (200 THAs) before adoption of novel techniques. Component position was measured on plain radiographs. Radiographic measurements were taken by 2 blinded observers. The percentage of hips within the surgeons' "target zone" (inclination, 30°-50°; anteversion, 10°-30°) was calculated, along with the percentage within the "safe zone" of Lewinnek (inclination, 30°-50°; anteversion, 5°-25°) and Callanan (inclination, 30°-45°; anteversion, 5°-25°). Relative risk (RR) and absolute risk reduction (ARR) were calculated. Variances (square of the standard deviations) were used to describe the variability of cup position. Seventy-six percentage of MP THAs were within the surgeons' target zone compared with 84% of FA THAs and 97% of RP THAs. This difference was statistically significant, associated with a RR reduction of 87% (RR, 0.13 [0.04-0.40]; P < .01; ARR, 21%; number needed to treat, 5) for RP compared to MP THAs. Compared to FA THAs, RP THAs were associated with a RR reduction of 81% (RR, 0.19 [0.06-0.62]; P < .01; ARR, 13%; number needed to treat, 8). Variances were lower for acetabulum inclination and anteversion in RP THAs (14.0 and 19.5) as compared to the MP (37.5 and 56.3) and FA (24.5 and 54.6) groups. These differences were statistically significant (P < .01). Adoption of robotic techniques delivers significant and immediate improvement in the precision of acetabular component positioning during the learning curve. While fluoroscopy has been shown to be beneficial with experience, a learning curve exists before precision improves significantly. Copyright © 2016 Elsevier Inc. All rights reserved.

Cup inclination angle of greater than 50 degrees increases whole blood concentrations of cobalt and chromium ions after metal-on-metal hip resurfacing.

PubMed

Hart, A J; Buddhdev, P; Winship, P; Faria, N; Powell, J J; Skinner, J A

2008-01-01

A cup inclination angle greater than 45 degrees is associated with increased wear rates of metal on polyethylene (MOP) hip replacements. The same maybe true for metal on metal (MOM) hips yet this has not been clearly shown. We measured the acetabular inclination angle from plain radiographs, and whole blood metal ion levels using Inductively Coupled Plasma Mass Spectrometry of 26 patients (mean Harris Hip Score 94 and mean time post op of 22 months) with Birmingham Hip Resurfacings. We identified a threshold level of 50 degrees cup inclination. Below this threshold, the mean whole blood cobalt and chromium were 1.6 ppb and 1.88 ppb respectively; above this threshold, the mean blood cobalt and chromium were 4.45 ppb and 4.3 ppb respectively. These differences were significant cobalt (p<0.01) and chromium (p=0.01). All patients above the threshold had metal levels greater than any of the patients below the threshold. For 14 patients, who returned one year later for a repeat blood metal level measurement, cobalt and chromium levels were very similar. The effect of an acetabular inclination angle of greater than 50 degrees on wear rates of MOM hips, as measured through blood metal ion levels, appears to be similar to that seen with MOP hips. Additionally, our new analytical methods may allow blood metal levels to be used as a realistic biomarker of in vivo wear rate of MOM hips. The implication is that metal levels can be minimised with optimal orientation of the acetabular component.

A simple method of measuring the wear of explanted acetabular component inserts

PubMed Central

Krakow, L.; Klockow, A.; Roehner, E.; Brodt, S.; Eijer, H.; Bossert, J.

2017-01-01

Objectives The determination of the volumetric polyethylene wear on explanted material requires complicated equipment, which is not available in many research institutions. Our aim in this study was to present and validate a method that only requires a set of polyetheretherketone balls and a laboratory balance to determine wear. Methods The insert to be measured was placed on a balance, and a ball of the appropriate diameter was inserted. The cavity remaining between the ball and insert caused by wear was filled with contrast medium and the weight of the contrast medium was recorded. The volume was calculated from the known density of the liquid. The precision, inter- and intraobserver reliability, were determined by four investigators on four days using nine inserts with specified wear (0.094 ml to 1.626 ml), and the intra-class correlation coefficient was calculated. The feasibility of using this method in routine clinical practice and the time required for measurement were tested on 84 explanted inserts by one investigator. Results In order to get the mean for all investigators and determinations, the deviation between the measured and specified wear was -0.08 ml (sd 0.12; -0.21 to 0.11). The interobserver reliability was 0.989 ml (95% confidence interval (CI) 0.964 to 0.997) and the intraobserver reliability was 0.941 for observer 1 (95% CI 0.846 to 0.985), 0.983 for observer 2 (95% CI 0.956 to 0.995), 0.939 for observer 3 (95% CI 0.855 to 0.984), and 0.934 for observer 4 (95% CI 0.790 to 0.984). The mean time required to examine the samples was two minutes (sd 2; 1 to 5). Conclusion The method presented here was shown to be sufficiently precise for many settings and is a cost-effective and quick method of determining the volumetric wear of explanted acetabular components. However, the measurement of wear for scientific purposes will probably continue to involve more accurate and dedicated laboratory equipment. Cite this article: L. Krakow, A. Klockow, E. Roehner, S. Brodt, H. Eijer, J. Bossert, G. Matziolis. A simple method of measuring the wear of explanted acetabular component inserts. Bone Joint Res 2017;6:530–534. DOI: 10.1302/2046-3758.69.BJR-2016-0249.R1 PMID:28899855

Arthroscopic treatment of femoral nerve paresthesia caused by an acetabular paralabral cyst.

PubMed

Kanauchi, Taira; Suganuma, Jun; Mochizuki, Ryuta; Uchikawa, Shinichi

2014-05-01

This report describes a rare case of femoral nerve paresthesia caused by an acetabular paralabral cyst of the hip joint. A 68-year-old woman presented with a 6-month history of right hip pain and paresthesia along the anterior thigh and radiating down to the anterior aspect of the knee. Radiography showed osteoarthritis with a narrowed joint space in the right hip joint. Magnetic resonance imaging showed a cyst with low T1- and high T2-weighted signal intensity arising from a labral tear at the anterior aspect of the acetabulum. The cyst was connected to the joint space and displaced the femoral nerve to the anteromedial side. The lesion was diagnosed as an acetabular paralabral cyst causing femoral neuropathy. Because the main symptom was femoral nerve paresthesia and the patient desired a less invasive procedure, arthroscopic labral repair was performed to stop synovial fluid flow to the paralabral cyst that was causing the femoral nerve paresthesia. After surgery, the cyst and femoral nerve paresthesia disappeared. At the 18-month follow-up, the patient had no recurrence. There have been several reports of neurovascular compression caused by the cyst around the hip joint. To the authors' knowledge, only 3 cases of acetabular paralabral cysts causing sciatica have been reported. The current patient appears to represent a rare case of an acetabular paralabral cyst causing femoral nerve paresthesia. The authors suggest that arthroscopic labral repair for an acetabular paralabral cyst causing neuropathy can be an option for patients who desire a less invasive procedure. Copyright 2014, SLACK Incorporated.

How often does open reduction and internal fixation of geriatric acetabular fractures lead to hip arthroplasty?

PubMed

O'Toole, Robert V; Hui, Emily; Chandra, Amit; Nascone, Jason W

2014-03-01

We hypothesized that open reduction and internal fixation (ORIF) of displaced acetabular fractures in geriatric patients result in a low rate of conversion to hip arthroplasty and satisfactory hip-specific validated outcome scores at medium-term follow-up. Retrospective review. Level I trauma center. One hundred forty-seven consecutive patients who were 60 years or older who had acetabular fractures were treated at our center from 2001 through 2006. During this time period, fractures meeting operative criteria were treated with ORIF unless medical conditions warranted nonoperative treatment. Twenty-nine patients were lost to follow-up, 46 were deceased, and 11 declined to participate, leaving 61 potential patients for inclusion, 46 of whom were treated with ORIF (average follow-up, 4.4 years; range, 1.1-8.0 years). Standardized telephone interviews included hip-specific questions and validated outcome measures. Rates of conversion to hip arthroplasty and hip-specific validated outcome scores. Among 46 patients treated with ORIF (15 others were treated nonoperatively or with percutaneous screw fixation), 28% underwent hip arthroplasty an average 2.5 years after injury (range, 0.4-5.5 years) and had an average Western Ontario and McMaster Universities Index of Osteoarthritis score of 17 (range, 0-56; n = 38). This score is similar to or better than the typical scores after elective arthroplasty for arthritis and much better than the scores for patients with established arthritis (P < 0.05). The average SF-8 Health Survey physical component score was 46.1 (range, 31-62), similar to US population norms for the geriatric age group (P > 0.20). Few data exist regarding the treatment outcomes for geriatric acetabular fractures. It is difficult for clinicians to decide among ORIF, percutaneous fixation, acute arthroplasty, and nonoperative treatment. Our protocol of mostly ORIF showed a high 1-year mortality rate of 25% and a rate of conversion to arthroplasty after ORIF of 28%. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Investigation into three dimensional hip anatomy in anterior dislocation after THA. Influence of the position of the hip rotation centre.

PubMed

Sariali, Elhadi; Klouche, Shahnez; Mamoudy, Patrick

2012-07-01

The components position is a major factor under the surgeon's control in determining the risk of dislocation post total hip arthroplasty. The aim of this study was to investigate the proper three-dimensional components position including the centre of rotation in the case of anterior dislocation. Among 1764 consecutive patients who underwent total hip arthroplasty using a direct anterior approach, 27 experienced anterior dislocation. The three-dimensional hip anatomy was investigated in 12 patients who were paired with 12 patients from the same initial cohort who did not experience dislocation and also with 36 control patients with osteoarthritis. A pelvic Cartesian referential was defined to perform the acetabular analysis. The coordinates were expressed as percentages of the pelvic width, height and depth. The anteversion angles were measured. The hip centre of rotation was significantly shifted medially and posteriorly in the dislocation group when compared to the non-dislocation group and also to the control group. There was no significant difference in component angular position between the dislocation-group and the non-dislocation group. However, the stem anteversion in the dislocation group was increased in comparison to the mean natural femoral anteversion of the control group. A medial and posterior displacement of the hip rotation centre was found to correlate to anterior dislocation post total hip arthoplasty. These results suggest the importance of an accurate restoration of the centre of rotation, whilst avoiding an excessive acetabular reaming which may induce a medial and a posterior displacement. III comparative non randomised. Copyright © 2011 Elsevier Ltd. All rights reserved.

Validity and reliability of the Paprosky acetabular defect classification.

PubMed

Yu, Raymond; Hofstaetter, Jochen G; Sullivan, Thomas; Costi, Kerry; Howie, Donald W; Solomon, Lucian B

2013-07-01

The Paprosky acetabular defect classification is widely used but has not been appropriately validated. Reliability of the Paprosky system has not been evaluated in combination with standardized techniques of measurement and scoring. This study evaluated the reliability, teachability, and validity of the Paprosky acetabular defect classification. Preoperative radiographs from a random sample of 83 patients undergoing 85 acetabular revisions were classified by four observers, and their classifications were compared with quantitative intraoperative measurements. Teachability of the classification scheme was tested by dividing the four observers into two groups. The observers in Group 1 underwent three teaching sessions; those in Group 2 underwent one session and the influence of teaching on the accuracy of their classifications was ascertained. Radiographic evaluation showed statistically significant relationships with intraoperative measurements of anterior, medial, and superior acetabular defect sizes. Interobserver reliability improved substantially after teaching and did not improve without it. The weighted kappa coefficient went from 0.56 at Occasion 1 to 0.79 after three teaching sessions in Group 1 observers, and from 0.49 to 0.65 after one teaching session in Group 2 observers. The Paprosky system is valid and shows good reliability when combined with standardized definitions of radiographic landmarks and a structured analysis. Level II, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Different thermal conductivity in drilling of cemented compared with cementless hip prostheses in the treatment of periprosthetic fractures of the proximal femur: an experimental biomechanical analysis.

PubMed

Brand, Stephan; Klotz, Johannes; Hassel, Thomas; Petri, Maximilian; Ettinger, Max; Krettek, Christian; Goesling, Thomas; Bach, Friedrich-Wilhelm

2013-10-01

The purpose of this study was to evaluate the different temperature levels whilst drilling cemented and cementless hip prostheses implanted in bovine femora, and to evaluate the insulating function of the cement layer. Standard hip prostheses were implanted in bovine donor diaphyses, with or without a cement layer. Drilling was then performed using high-performance-cutting drills with a reinforced core, a drilling diameter of 5.5 mm and cooling channels through the tip of the drill for constantly applied internal cooling solution. An open type cooling model was used in this setup. Temperature was continuously measured by seven thermocouples placed around the borehole. Thermographic scans were also performed during drilling. At the cemented implant surface, the temperature never surpassed 24.7 °C when constantly applied internal cooling was used. Without the insulating cement layer (i.e. during drilling of the cementless bone-prosthesis construct), the temperature increased to 47 °C. Constantly applied internal cooling can avoid structural bone and soft tissue damage during drilling procedures. With a cement layer, the temperatures only increased to non-damaging levels. The results could be useful in the treatment of periprosthetic fractures with intraprosthetic implant fixation.

Intra-operative evaluation of cementless hip implant stability: a prototype device based on vibration analysis.

PubMed

Lannocca, Maurizio; Varini, Elena; Cappello, Angelo; Cristofolini, Luca; Bialoblocka, Ewa

2007-10-01

Cementless implants are mechanically stabilized during surgery by a press-fitting procedure. Good initial stability is crucial to avoid stem loosening and bone cracking, therefore, the surgeon must achieve optimal press-fitting. A possible approach to solve this problem and assist the surgeon in achieving the optimal compromise, involves the use of vibration analysis. The present study aimed to design and test a prototype device able to evaluate the primary mechanical stability of a cementless prosthesis, based on vibration analysis. In particular, the goal was to discriminate between stable and quasi-stable implants; thus the stem-bone system was assumed to be linear in both cases. For that reason, it was decided to study the frequency responses of the system, instead of the harmonic distortion. The prototype developed consists of a piezoelectric exciter connected to the stem and an accelerometer attached to the femur. Preliminary tests were performed on four composite femurs implanted with a conventional stem. The results showed that the input signal was repeatable and the output could be recorded accurately. The most sensitive parameter to stability was the shift in resonance frequency of the stem-bone system, which was highly correlated with residual micromotion on all four specimens.

A Multicenter Approach Evaluating the Impact of Vitamin E-Blended Polyethylene in Cementless Total Hip Replacement

PubMed Central

Jäger, Marcus; van Wasen, Andrea; Warwas, Sebastian; Landgraeber, Stefan; Haversath, Marcel; Group, VITAS

2014-01-01

Since polyethylene is one of the most frequently used biomaterials as a liner in total hip arthroplasty, strong efforts have been made to improve design and material properties over the last 50 years. Antioxidants seems to be a promising alternative to further increase durability and reduce polyethylene wear in long term. As of yet, only in vitro results are available. While they are promising, there is yet no clinical evidence that the new material shows these advantages in vivo. To answer the question if vitamin-E enhanced ultra-high molecular weight polyethylene (UHMWPE) is able to improve long-term survivorship of cementless total hip arthroplasty we initiated a randomized long-term multicenter trial. Designed as a superiority study, the oxidation index assessed in retrieval analyses of explanted liners was chosen as primary parameter. Radiographic results (wear rate, osteolysis, radiolucency) and functional outcome (Harris Hip Scores, University of California-Los Angeles, Hip Disability and Osteoarthritis Outcome Score, Visual Analogue Scale) will serve as secondary parameters. Patients with the indication for a cementless total hip arthroplasty will be asked to participate in the study and will be randomized to either receive a standard hip replacement with a highly cross-linked UHMWPE-X liner or a highly cross-linked vitamin-E supplemented UHMWPE-XE liner. The follow-up will be 15 years, with evaluation after 5, 10 and 15 years. The controlled randomized study has been designed to determine if Vitamin-E supplemented highly cross-linked polyethylene liners are superior to standard XLPE liners in cementless total hip arthroplasty. While several studies have been started to evaluate the influence of vitamin-E, most of them evaluate wear rates and functional results. The approach used for this multicenter study, to analyze the oxidation status of retrieved implants, should make it possible to directly evaluate the ageing process and development of the implant material itself over a time period of 15 years. PMID:25002933

Preparation of the Femoral Bone Cavity for Cementless Stems: Broaching vs Compaction. A Five-Year Randomized Radiostereometric Analysis and Dual Energy X-Ray Absorption Study.

PubMed

Hjorth, Mette H; Kold, Søren; Søballe, Kjeld; Langdahl, Bente L; Nielsen, Poul T; Christensen, Poul H; Stilling, Maiken

2017-06-01

Short-term experimental and animal studies have confirmed superior fixation of cementless implants inserted with compaction compared to broaching of the cancellous bone. Forty-four hips in 42 patients (19 men) were randomly operated using cementless hydroxyapatite-coated Bi-Metric stems. Patients were followed with radiostereometric analysis at baseline, 6 and 12 weeks, 1, 2, and 5 years, and measurements of periprosthetic bone mineral density at baseline, 1, 2, and 5 years. Complications during the study period and clinical outcome measures of Harris Hip Score were recorded at mean 7 years (5-8.8) after surgery. Absolute migrations of medio/lateral translations between the broaching group and the compaction group of mean 0.14 mm (standard deviation [SD] 0.10) vs mean 0.30 mm (SD 0.27) (P = .01) at 1 year, and of mean 0.13 mm (SD 0.10) vs 0.34 mm (0.31) (P = .01) at 5 years were different. Absolute valgus/varus rotations of mean 0.12° (SD 0.13°) in the broaching group were less than mean 0.35° (0.45°) in the compaction group (P < .01) at 1 year, but at 5 years no difference was observed (P = .19). Subsidence and retroversion were similar between groups at all follow-ups (P > .13). The compaction group had significantly less bone loss than the broaching group in Gruen zone 3 (distal-lateral to the stem) at 1 and 5 years. No further differences in bone mineral density changes were found between groups up to 5 years after surgery. Complications throughout the period and clinical outcome measures of Harris Hip Score were similar at 7 years (5-8.8) after surgery. We found increased migration when preparing the bone with compaction compared with broaching in cementless femoral stems. Copyright © 2017 Elsevier Inc. All rights reserved.

Change in Acetabular Cup Orientation From Supine to Standing Position and Its Effect on Wear of Highly Crosslinked Polyethylene.

PubMed

Teeter, Matthew G; Goyal, Prateek; Yuan, Xunhua; Howard, James L; Lanting, Brent A

2018-01-01

The purpose of this study is to measure acetabular cup position and wear of the highly crosslinked polyethylene liner in the supine and standing position for patients at a minimum of 10 years after the operation. A total of 38 patients were recruited at a mean of 12.5 years after the operation. All patients received a single acetabular cup design with a highly crosslinked liner and a 28-mm cobalt-chromium femoral head. Patients underwent supine and standing radiostereometric examinations in which the X-ray sources and detectors were positioned to obtain an anterior-posterior and cross-table lateral radiograph. Acetabular cup position and the three-dimensional wear rate were measured from the radiographs, and outcome scores were recorded for each patient. Anteversion significantly increased (P < .0001) a mean of 12° from supine (15.1° ± 10.4°) to standing (27.2° ± 10.5°) position. Inclination also significantly increased (P = .001) a mean of 2° from supine (44.4° ± 6.8°) to standing (46.3° ± 7.7°) position. There was no difference (P = .093) in wear rate between supine (0.067 ± 0.070 mm/y) and standing (0.073 ± 0.074 mm/y) positions. There were no correlations between cup orientation and wear rate in either position. Highly crosslinked polyethylene is a forgiving bearing material. Although adherence to the traditional acetabular position target zone is recommended, ensuring hip stability and consideration of the patient's functional position are also important objectives to consider for the acetabular position. Copyright © 2017 Elsevier Inc. All rights reserved.

Bilaterally Primary Cementless Total Hip Arthroplasty for Severe Hip Ankylosis with Ankylosing Spondylitis.

PubMed

Feng, Dong-Xu; Zhang, Kun; Zhang, Yu-Min; Nian, Yue-Wen; Zhang, Jun; Kang, Xiao-Min; Wu, Shu-Fang; Zhu, Yang-Jun

2016-08-01

Total hip arthroplasty is a reliable therapeutic intervention in patients with ankylosing spondylitis, in whom the aims of surgery are to reduce pain, restore hip function and improve quality of life. The current study is a retrospective analysis of the clinical and radiographic findings in a consecutive series of patients with hip ankylosis associated with severe ankylosing spondylitis who underwent bilateral primary total hip arthroplasty using non-cemented components. From June 2008 to May 2012, total hip arthroplasty was performed on 34 hips in 17 patients with bilateral ankylosis caused by ankylosing spondylitis. The study patients included 13 men and 4 women with a mean age of 24.2 years. The mean duration of disease was 8.3 years and the average duration of hip involvement was 7.6 years. All patients had severe hip pain and dysfunction with bilateral bony ankylosis and no range of motion preoperatively and all underwent bilateral cementless total hip arthroplasty performed by a single surgeon. Joint pain, range of motion (ROM), and Harris hip scores were assessed to evaluate the postoperative results. At a mean follow-up of 31.7 months, all patients had experienced significant clinical improvement in function, ROM, posture and ambulation. At the final follow-up, the mean postoperative flexion ROM was 134.4° compared with 0° preoperatively. Similar improvements were seen in hip abduction, adduction, internal rotation and external rotation. Postoperatively, 23 hips were completely pain-free, six had only occasional discomfort, three mild to moderate pain and two severe pain. The average Harris Hip Score improved from 23.7 preoperatively to 65.8 postoperatively. No stems had loosened at the final follow-up in any patient, nor had any revision surgery been required. Bilateral severe hip ankylosis in patients with ankylosing spondylitis can be treated with cementless bilateral synchronous total hip arthroplasty, which can greatly improve hip joint function and relieve pain without significant complications. Provided the overall physical condition of a patient and their economic situation make surgery a feasible option and the surgeon is experienced, this treatment is a worthwhile surgical intervention for bilateral hip bony ankylosis. However, the technically demanding nature of the procedure and potential pre- and post-operative problems should not be underestimated. © 2016 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

Should money follow the patient: Financial implication for being the National Centre for the Treatment and Management of Pelvic and Acetabular Fractures in Ireland.

PubMed

Kelly, M E; Leonard, M; Green, C; Beggs, R; Cheung, C; McElwain, J; Morris, S

2013-12-01

Pelvic and acetabular fractures are complex injuries requiring specialist treatment. Our institution is the National Centre for Treatment and Management of these injuries. To audit all referrals to our institution over a 6-month period and calculate the cost incurred by being the national referral centre. Retrospective review of database, and subsequent allocation of Casemix points to assess total cost of treatment for each patient referred to our institution. 103 patients referred with pelvic or acetabular fracture for operative management. The furthest referral distance was 181miles. Over-all, the length of stay was 15.4 days. The average inclusive cost for a referral to our unit for operative management was €16,302. Pelvic and acetabular fractures are complex injuries that require specialist referral unit management. However for these units to remain sustainable money needs to "follow the patient". Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Sonographic investigation of anatomical specimens of infant hip joints.

PubMed

Falliner, Axel; Hahne, Hans-Jürgen; Hassenpflug, Joachim

2002-07-01

The anatomical foundations of infant hip sonography techniques are ill-defined. We investigated anatomical specimens of infant hip joints in a water bath, with Graf's and Terjesen's methods. Acetabular position was varied in defined increments, with respect to the ultrasound beam. The alpha angles and the femoral head coverage were measured. Plastic acetabular casts were sawn along the sonographic section planes, and the cut sections compared with the sonographic sections. For images to be obtained, which were analysable by the two methods, the ultrasound beam had to intersect with the acetabular inlet plane at defined angles. The acetabular notch had to be anteriorly rotated from the ultrasound beam plane by at least 20 degrees. Beam entry within a 50 degrees sector posterior to the perpendicular on the inlet plane gave analysable images. The alpha angles and femoral head coverage were much affected by coronal-plane transducer tilt. Caudad tilts were associated with lesser values, a fact that should be borne in mind in clinical ultrasound investigations.

[Stress analysis on the acetabular side of bipolar hemiarthroplasty by the two-dimensional finite element method incorporating the boundary friction layer].

PubMed

Ichihashi, K; Imura, S; Oomori, H; Gesso, H

1994-11-01

We compared the biomechanical characteristics of bipolar and unipolar hemiarthroplasty on the proximal migration of the outer head by determining the von Mises stress distribution and acetabular (outer head) displacement with clinical assessment of hemiarthroplasty in 75 patients. This analysis used the two-dimensional finite element method, which incorporated boundary friction layers on both the inner and outer bearings of the prosthesis. Acetabular reaming increased stress within the pelvic bone and migration of the outer head. A combination of the acetabular reaming and bone transplantation increased the stress within the pelvic bone and grafted bone, and caused outer head migration. These findings were supported by clinical results. Although the bipolar endoprosthesis was biomechanically superior to the unipolar endoprosthesis, migration of the outer head still occurred. The bipolar endoprosthesis appeared to be indicated in cases of a femoral neck fracture or of avascular necrosis in the femoral head, but its use in cases of osteoarthritis in the hip required caution.

Perioperative and acute care outcomes in morbidly obese patients with acetabular fractures at a Level 1 trauma center

PubMed Central

Vincent, Heather K.; Haupt, Edward; Tang, Sonya; Egwuatu, Adaeze; Vlasak, Richard; Horodyski, MaryBeth; Carden, Donna; Sadisivan, Kalia K.

2014-01-01

Background Controversy exists regarding obesity-related injury severity and clinical outcomes after orthopedic trauma. Purpose The purposes of this study were to expand our understanding of the effect of morbid obesity on perioperative and acute care outcomes after acetabular fracture. Methods This was a retrospective review of patients with acetabular fracture after trauma. Non-morbidly obese (BMI < 35 kg/m2) and morbidly obese (BMI ≥ 35 kg/m2; N = 81). Injury severity scores and Glasgow Coma Scale scores (GCS) were collected. Perioperative and acute care outcomes were positioning and operative time, extra fractures, estimated blood loss, complications, hospital charges, ventilator days, transfusions, length of stay (LOS) and discharge destination. Positioning and operative times were longer in morbidly obese patients (p < 0.05). No other differences existed between groups. Conclusions Orthopedic trauma surgeons and care teams can expect similar acute care outcomes in morbidly obese and non-morbidly obese patients with acetabular fracture. PMID:25104886

A novel approach for determining three-dimensional acetabular orientation: results from two hundred subjects.

PubMed

Higgins, Sean W; Spratley, E Meade; Boe, Richard A; Hayes, Curtis W; Jiranek, William A; Wayne, Jennifer S

2014-11-05

The inherently complex three-dimensional morphology of both the pelvis and acetabulum create difficulties in accurately determining acetabular orientation. Our objectives were to develop a reliable and accurate methodology for determining three-dimensional acetabular orientation and to utilize it to describe relevant characteristics of a large population of subjects without apparent hip pathology. High-resolution computed tomography studies of 200 patients previously receiving pelvic scans for indications not related to orthopaedic conditions were selected from our institution's database. Three-dimensional models of each osseous pelvis were generated to extract specific anatomical data sets. A novel computational method was developed to determine standard measures of three-dimensional acetabular orientation within an automatically identified anterior pelvic plane reference frame. Automatically selected points on the osseous ridge of the acetabulum were used to generate a best-fit plane for describing acetabular orientation. Our method showed excellent interobserver and intraobserver agreement (an intraclass correlation coefficient [ICC] of >0.999) and achieved high levels of accuracy. A significant difference between males and females in both anteversion (average, 3.5°; 95% confidence interval [CI], 1.9° to 5.1° across all angular definitions; p < 0.0001) and inclination (1.4°; 95% CI, 0.6° to 2.3° for anatomic angular definition; p < 0.002) was observed. Intrapatient asymmetry in anatomic measures showed bilateral differences in anteversion (maximum, 12.1°) and in inclination (maximum, 10.9°). Significant differences in acetabular orientation between the sexes can be detected only with accurate measurements that account for the entire acetabulum. While a wide range of interpatient acetabular orientations was observed, the majority of subjects had acetabula that were relatively symmetrical in both inclination and anteversion. A highly accurate and reproducible method for determining the orientation of the acetabulum's aperture will benefit both surgeons and patients, by further refining the distinctions between normal and abnormal hip characteristics. Enhanced understanding of the acetabulum could be useful in the diagnostic, planning, and execution stages for surgical procedures of the hip or in advancing the design of new implant systems. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

[Charnley-type total hip prosthesis. Radiological technic of angular measurements of the acetabular piece (anteversion)].

PubMed

Chevrot, A; Najman, G

1983-01-01

A radiological technique is described based on the study of antero-posterior and lateral views of the hip. Mathematical calculations by trigonometry make it possible to deduce the degree of anteversion of the acetabular cup. The necessary tables are given.

Bone Remodeling in Acetabular Reconstruction Using a Kerboull-Type Reinforcement Device and Structural Bone-Grafting in Total Hip Arthroplasty.

PubMed

Oe, Kenichi; Iida, Hirokazu; Tsuda, Kohei; Nakamura, Tomohisa; Okamoto, Naofumi; Ueda, Yusuke

2017-03-01

The purpose of this study was to identify the long-term durability of the Kerboull-type reinforcement device (KT plate) in acetabular reconstruction for massive bone defects, assessing the remodeling of structural bone grafts. This study retrospectively evaluated 106 hips that underwent acetabular reconstruction using a KT plate between November 2000 and December 2010. Thirty-eight primary total hip arthoplasties (THAs) and 68 revised THAs were performed, and the mean duration of clinical follow-up was 8 years (5-14 years). Regarding reconstructing the acetabular bone defects, autografts were used in 37 hips, allografts in 68 hips, and A-W glass ceramics in 2 hips. One hip exhibited radiological migration and no revision for aseptic loosening. The mean Merle d'Aubigné Clinical Score improved from 7.5 points (4-12 points) preoperatively to 10.9 points (9-18 points) at the last follow-up. The Kaplan-Meier survival rate for radiological migration of primary and revised THAs at 10 years was 100% and 97% (95% confidence interval: 96%-100%), respectively. Bone remodeling was evaluated using the radiological demarcation at the bone-to-bone interface, and an improvement of 100% in primary THAs and 94% in revised THAs was observed. For massive bone defects, acetabular reconstruction using the KT plate with a structural bone grafting can yield successful results. Copyright © 2016 Elsevier Inc. All rights reserved.

A new approach for assessment of wear in metal-backed acetabular cups using computed tomography: a phantom study with retrievals.

PubMed

Jedenmalm, Anneli; Noz, Marilyn E; Olivecrona, Henrik; Olivecrona, Lotta; Stark, Andre

2008-04-01

Polyethylene wear is an important cause of aseptic loosening in hip arthroplasty. Detection of significant wear usually happens late on, since available diagnostic techniques are either not sensitive enough or too complicated and expensive for routine use. This study evaluates a new approach for measurement of linear wear of metal-backed acetabular cups using CT as the intended clinically feasible method. 8 retrieved uncemented metal-backed acetabular cups were scanned twice ex vivo using CT. The linear penetration depth of the femoral head into the cup was measured in the CT volumes using dedicated software. Landmark points were placed on the CT images of cup and head, and also on a reference plane in order to calculate the wear vector magnitude and angle to one of the axes. A coordinate-measuring machine was used to test the accuracy of the proposed CT method. For this purpose, the head diameters were also measured by both methods. Accuracy of the CT method for linear wear measurements was 0.6 mm and wear vector angle was 27 degrees . No systematic difference was found between CT scans. This study on explanted acetabular cups shows that CT is capable of reliable measurement of linear wear in acetabular cups at a clinically relevant level of accuracy. It was also possible to use the method for assessment of direction of wear.

Validation of a 3D CT method for measurement of linear wear of acetabular cups.

PubMed

Jedenmalm, Anneli; Nilsson, Fritjof; Noz, Marilyn E; Green, Douglas D; Gedde, Ulf W; Clarke, Ian C; Stark, Andreas; Maguire, Gerald Q; Zeleznik, Michael P; Olivecrona, Henrik

2011-02-01

We evaluated the accuracy and repeatability of a 3D method for polyethylene acetabular cup wear measurements using computed tomography (CT). We propose that the method be used for clinical in vivo assessment of wear in acetabular cups. Ultra-high molecular weight polyethylene cups with a titanium mesh molded on the outside were subjected to wear using a hip simulator. Before and after wear, they were (1) imaged with a CT scanner using a phantom model device, (2) measured using a coordinate measurement machine (CMM), and (3) weighed. CMM was used as the reference method for measurement of femoral head penetration into the cup and for comparison with CT, and gravimetric measurements were used as a reference for both CT and CMM. Femoral head penetration and wear vector angle were studied. The head diameters were also measured with both CMM and CT. The repeatability of the method proposed was evaluated with two repeated measurements using different positions of the phantom in the CT scanner. The accuracy of the 3D CT method for evaluation of linear wear was 0.51 mm and the repeatability was 0.39 mm. Repeatability for wear vector angle was 17°. This study of metal-meshed hip-simulated acetabular cups shows that CT has the capacity for reliable measurement of linear wear of acetabular cups at a clinically relevant level of accuracy.

Multi-pelvis characterisation of articular cartilage geometry.

PubMed

Gillard, Faye C; Dickinson, Alexander S; Schneider, Urs; Taylor, Andrew C; Browne, Martin

2013-12-01

The shape of the acetabular cartilage follows the contact stress distribution across the joint. Accurate characterisation of this geometry may be useful for the development of acetabular cup devices that are more biomechanically compliant. In this study, the geometry of the acetabular cartilage was characterised by taking plaster moulds of the acetabulum from 24 dry bone human pelvises and digitising the mould shapes using a three-dimensional laser scanner. The articular bone surface geometry was analysed, and the shape of the acetabulum was approximated by fitting a best-fit sphere. To test the hypothesis that the acetabulum is non-spherical, a best-fit ellipsoid was also fitted to the geometry. In each case, points around the acetabular notch edge that disclosed the articular surface geometry were identified, and vectors were drawn between these and the best-fit sphere or ellipsoid centre. The significantly larger z radii (into the pole) of the ellipsoids indicated that the acetabulum was non-spherical and could imply that the kinematics of the hip joint is more complex than purely rotational motion, and the traditional ball-and-socket replacement may need to be updated to reflect this motion. The acetabular notch edges were observed to be curved, with males exhibiting deeper, wider and shorter notches than females, although the difference was not statistically significant (mean: p = 0.30) and supports the use of non-gender-specific models in anatomical studies.

Incidence of Ceramic Liner Malseating After Ceramic-on-Ceramic Total Hip Arthroplasty Associated With Osteolysis: A 5- to 15-Year Follow-Up Study.

PubMed

Higuchi, Yoshitoshi; Hasegawa, Yukiharu; Komatsu, Daigo; Seki, Taisuke; Ishiguro, Naoki

2017-05-01

The aim of our study was to evaluate the clinical and radiographic outcomes of malseating of the acetabular liner in ceramic-on-ceramic total hip arthroplasty (THA). Outcomes for 160 ceramic-on-ceramic THAs, contributed by 116 women and 39 men, were evaluated. Clinical and radiographic measurements were obtained over a 5- to 15-year follow-up for analysis. Liner malseating was identified in 20% of cases. Outcomes for 32 cases with liner malseating (group A) were compared to outcomes for 128 joints with correct liner seating (group B). The Harris hip score at the last follow-up was 90.1 for group A and 89.6 for group B. Osteolysis was identified in 5 cases in group A (15.6%), compared to 3 cases in group B (P < .001). No significant between-group differences were identified with regard to ceramic fracture, audible squeaking, loosening of components, and revision THA. The mean annual liner wear rate was comparable between groups, 0.0045 mm/y for group A and 0.0039 mm/y for group B. The 10-year Kaplan-Meier survivorship, based on an end point of revision THA, was 100% for group A and 99.0% for group B. Over a moderate-length follow-up of 5-15 years, malseating of the acetabular liner was not associated with negative clinical outcomes or THA survivorship. Malseating did increase the incidence of osteolysis, a risk factor for adverse effects. Long-term follow-up studies are needed to fully quantify the effects of malseating of the acetabular liner. Copyright © 2016 Elsevier Inc. All rights reserved.

Acetabular Global Insufficiency in Patients with Down Syndrome and Hip-Related Symptoms: A Matched-Cohort Study.

PubMed

Bulat, Evgeny; Maranho, Daniel A; Kalish, Leslie A; Millis, Michael B; Kim, Young-Jo; Novais, Eduardo N

2017-10-18

The etiology of hip instability in Down syndrome is not completely understood. We investigated the morphology of the acetabulum and femur in patients with Down syndrome and compared measurements of the hips with those of matched controls. Computed tomography (CT) images of the pelvis of 42 patients with Down syndrome and hip symptoms were compared with those of 42 age and sex-matched subjects without Down syndrome or history of hip disease who had undergone CT for abdominal pain. Each of the cohorts had 23 male and 19 female subjects. The mean age (and standard deviation) in each cohort was 11.3 ± 5.3 years. The lateral center-edge angle (LCEA), acetabular inclination angle (IA), acetabular depth-width ratio (ADR), acetabular version, and anterior and posterior acetabular sector angles (AASA and PASA) were compared. The neck-shaft angle and femoral version were measured in the patients with Down syndrome only. The hips of the patients with Down syndrome were further categorized as stable (n = 21) or unstable (n = 63) for secondary analysis. The hips in the Down syndrome group had a smaller LCEA (mean, 10.8° ± 12.6° compared with 25.6° ± 4.6°; p < 0.0001), a larger IA (mean, 17.4° ± 10.3° compared with 10.9° ± 4.8°; p < 0.0001), a lower ADR (mean, 231.9 ± 56.2 compared with 306.8 ± 31.0; p < 0.0001), a more retroverted acetabulum (mean acetabular version as measured at the level of the centers of the femoral heads [AVC], 7.8° ± 5.1° compared with 14.0° ± 4.5°; p < 0.0001), a smaller AASA (mean, 55.0° ± 9.9° compared with 59.7° ± 7.8°; p = 0.005), and a smaller PASA (mean, 67.1° ± 10.4° compared with 85.2° ± 6.8°; p < 0.0001). Within the Down syndrome cohort, the unstable hips showed greater femoral anteversion (mean, 32.7° ± 14.6° compared with 23.6° ± 10.6°; p = 0.002) and worse global acetabular insufficiency compared with the stable hips. No differences between the unstable and stable hips were found with respect to acetabular version (mean AVC, 7.8° ± 5.5° compared with 7.6° ± 3.8°; p = 0.93) and the neck-shaft angle (mean, 133.7° ± 6.7° compared with 133.2° ± 6.4°; p = 0.81). Patients with Down syndrome and hip-related symptoms had more retroverted and shallower acetabula with globally reduced coverage of the femoral head compared with age and sex-matched subjects. Hip instability among those with Down syndrome was associated with worse global acetabular insufficiency and increased femoral anteversion, but not with more severe acetabular retroversion. No difference in the mean femoral neck-shaft angle was observed between the stable and unstable hips in the Down syndrome cohort. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Instability after total hip arthroplasty

PubMed Central

Werner, Brian C; Brown, Thomas E

2012-01-01

Instability following total hip arthroplasty (THA) is an unfortunately frequent and serious problem that requires thorough evaluation and preoperative planning before surgical intervention. Prevention through optimal index surgery is of great importance, as the management of an unstable THA is challenging even for an experienced joints surgeon. However, even after well-planned surgery, a significant incidence of recurrent instability still exists. Non-operative management is often successful if the components are well-fixed and correctly positioned in the absence of neurocognitive disorders. If conservative management fails, surgical options include revision of malpositioned components; exchange of modular components such as the femoral head and acetabular liner; bipolar arthroplasty; tripolar arthroplasty; use of a larger femoral head; use of a constrained liner; soft tissue reinforcement and advancement of the greater trochanter. PMID:22919568

Complications of porous-coated press-fit cementless total hip replacement in dogs.

PubMed

Kidd, Scott W; Preston, Christopher A; Moore, George E

2016-09-20

To report postoperative complications using a commercially available porous-coated press-fit cementless total hip replacement (THR) system in dogs. Medical records were reviewed for client-owned dogs with hip pathologies requiring THR. A minimum of six-week postoperative orthopaedic examination and orthogonal pelvic radiographs were used to assess outcome and complications in the perioperative period. Referring veterinarian medical records, phone interviews with clients, or both were used to assess long-term functional outcome and complications. Bilateral THR was performed in 36 dogs, and unilateral in 147 dogs, making a total of 219 THR procedures in 183 dogs. A total complication rate of 31.1% (68/219) was observed. A catastrophic complication was observed in 8.2% (n = 18), a major complication in 9.6% (n = 21), and a minor complication in 13.2% (n = 29) of procedures. The most common complications were intra-operative femoral fissure (n = 46), diaphyseal femoral fracture (n = 15), and coxofemoral luxation (n = 9). Full return to function was achieved in 88.1% of procedures with a median follow-up period of 42 months. Porous-coated press-fit cementless collarless total hip replacements have a high complication rate. The majority of complications occur intra-operatively or perioperatively, with few complications occurring beyond 12 weeks postoperatively. Both fissure fractures and diaphyseal femoral fractures carry a favourable prognosis with immediate cerclage wiring and plate fixation, respectively.

Prospective long-term follow-up of the cementless bicontact hip stem with plasmapore coating.

PubMed

Ochs, U; Eingartner, C; Volkmann, R; Ochs, B G; Huber, C; Weller, S; Weise, K

2007-01-01

A prospective long-term study of the first 250 cementless Bicontact stems implanted in the BG Trauma Centre, Tuebingen, Germany. All of the patients in this series (treatment period June 1987 to April 1990) who were still contactable were invited for clinical and radiological follow-up. The radiographs were analysed for signs of loosening in the form of Gruen lysis zones, stress shielding, subsidence behaviour, heterotopic ossification and spot welds. The average follow-up period was 17.8 (16.7 - 19.5) years. The overall rate of follow-up was 65 % (162 of 250) and 91 % of patients who were still alive (162 of 179). The average patient age was 56.2 years at the time of operation and 74.0 years at follow-up. The average HHS was 81.6 points. In the course of the first 10 years (up to 03/1998), a total of 8 stem revisions had to be performed. In the period from 03/1998 to 01/2007, 2 cases of loosening requiring revision occurred in the patients still alive at the time of follow-up. The survival rate calculated was thus 95.6 %. These outstanding results provide enduring support for the philosophy of the cementless and bone-preserving fixation principles underlying the Bicontact hip stem with proximal intertrochanteric transmission of forces and high primary rotational stability.

Biomechanical study of pelvic discontinuity in failed total hip arthroplasty. Lessons learnt from the treatment of pelvic fractures.

PubMed

Ribes-Iborra, Julio; Atienza, Carlos; Sevil-De la Torre, Jorge; Gómez Pérez, Amelia

2017-11-01

Pelvic discontinuity is a rare but serious problem in orthopedic surgery. Acetabular reconstruction in case of severe bone loss after failed total hip arthroplasty is technically difficult, especially in segmental loss type III (anterior or posterior) or pelvic discontinuity (type IV). Acetabular reinforcement devices are frequently used as load-sharing devices to allow allograft incorporation and in order to serve as support of acetabular implants. This study tries to show, by means of biomechanic work, the efficiency of reinforced plate in anterior column in a segmental pelvic loss, illustrated with a clinical case, which shows the socket stability of hip prosthesis. © 2017 Elsevier Ltd. All rights reserved.

Examination and treatment of a professional ballet dancer with a suspected acetabular labral tear: A case report.

PubMed

Khoo-Summers, Lynnette; Bloom, Nancy J

2015-08-01

Dancers are at risk for developing groin pain that is due to acetabular labral tears. Although surgical management of labral tears has been reported extensively, conservative management has been poorly described. This case report describes the examination, diagnosis, and treatment of groin pain in a professional ballet dancer with a suspected acetabular labral tear. Treatment focused on decreasing anterior hip joint stresses and improving the precision of hip motion through correction of alignment and movement impairments noted during functional activities and dance. Successful outcomes included a reduction in pain and return to professional ballet dancing. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Revision hip arthroplasty by Waldemar Link custom-made total hip prosthesis].

PubMed

Medenica, Ivica; Luković, Milan; Radoicić, Dragan

2010-02-01

The number of patients undergoing hip arthroplasty revision is constantly growing. Especially, complex problem is extensive loss of bone stock and pelvic discontinuity that requires reconstruction. The paper presented a 50-year old patient, who ten years ago underwent a total cement artrhroplasty of the left hip. A year after the primary operation the patient had difficulties in walking without crutches. Problems intensified in the last five years, the patient had severe pain, totally limited movement in the left hip and could not walk at all. Radiographically, we found loose femoral component, massive loss of bone stock of proximal femur, acetabular protrusion and a consequent pelvic discontinuity. Clinically, a completely disfunctional left hip joint was registered (Harris hip score--7.1). We performed total rearthroplasty by a custom-made Waldemar Link total hip prosthesis with acetabular antiprotrusio cage and compensation of bone defects with a graft from the bone bank. A year after the operation, we found clinically an extreme improvement in Harris hip score--87.8. Radiographically, we found stability of implanted components, a complete graft integration and bone bridging across the site of pelvic discontinuity. Pelvic discontinuity and massive loss of proximal femoral bone stock is a challenging and complex entity. Conventional prostheses cannot provide an adequate fixation and stability of the hip. Application of custom-made prosthesis (measured specificaly for a patient) and additional alografting bone defects is a good method in revision surgery after unsuccessful hip arthroplasty with extensive bone defects.

21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hip joint (hemi-hip) acetabular metal cemented prosthesis. 888.3370 Section 888.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3370 Hip joint...

21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hip joint (hemi-hip) acetabular metal cemented prosthesis. 888.3370 Section 888.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3370 Hip joint...

21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hip joint (hemi-hip) acetabular metal cemented prosthesis. 888.3370 Section 888.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3370 Hip joint...

Morphological experimental study of bone stress at the interface acetabular bone/prosthetic cup in the bipolar hip prosthesis.

PubMed

Anuşca, D; Pleşea, I E; Iliescu, N; Tomescu, P; Poenaru, F; Dascălu, V; Pop, O T

2006-01-01

By calculating the tension and distortion of the elements composing the bipolar prosthesis under extreme conditions encountered in real life using a special post-processing program, we established the variation curves of the contact pressure at the hip bone-cup, armor-cup and cup-femoral head interface. By comparing the data obtained from all the examined cases, important conclusions were drawn regarding the influence of tension and pressure distribution on the structural integrity and biomechanics of the prosthesis, as well as the acetabular wear and tear, in order to assess its reliability. The experimentally determined tension and distortion status at the acetabular bone-metal armour interface, lead to the wear and tear phenomenon, which can be explained by three mechanisms and theories incompletely reflecting the overall process. The histopathologic study of the acetabular bone tissue using FEM (finite elements method) on surgically removed specimens will probably lead to the identification of a series of factors that could reduce the rate of the wear and tear process.

[Stress analysis of femoral stems in cementless total hip arthroplasty by two-dimensional finite element method using boundary friction layer].

PubMed

Oomori, H; Imura, S; Gesso, H

1992-04-01

To develop stem design achieving primary fixation of stems and effective load transfer to the femur, we studied stress analysis of stems in cementless total hip arthroplasty by two-dimensional finite element method using boundary friction layer in stem-bone interface. The results of analyses of stem-bone interface stresses and von Mises stresses at the cortical bones indicated that ideal stem design features would be as follows: 1) Sufficient length, with the distal end extending beyond the isthmus region. 2) Maximum possible width, to contact the cortical bones in the isthmus region. 3) No collars but a lateral shoulder at the proximal portion. 4) A distal tip, to contact the cortical bones at the distal portion.

Validation of a 3D CT method for measurement of linear wear of acetabular cups

PubMed Central

2011-01-01

Background We evaluated the accuracy and repeatability of a 3D method for polyethylene acetabular cup wear measurements using computed tomography (CT). We propose that the method be used for clinical in vivo assessment of wear in acetabular cups. Material and methods Ultra-high molecular weight polyethylene cups with a titanium mesh molded on the outside were subjected to wear using a hip simulator. Before and after wear, they were (1) imaged with a CT scanner using a phantom model device, (2) measured using a coordinate measurement machine (CMM), and (3) weighed. CMM was used as the reference method for measurement of femoral head penetration into the cup and for comparison with CT, and gravimetric measurements were used as a reference for both CT and CMM. Femoral head penetration and wear vector angle were studied. The head diameters were also measured with both CMM and CT. The repeatability of the method proposed was evaluated with two repeated measurements using different positions of the phantom in the CT scanner. Results The accuracy of the 3D CT method for evaluation of linear wear was 0.51 mm and the repeatability was 0.39 mm. Repeatability for wear vector angle was 17°. Interpretation This study of metal-meshed hip-simulated acetabular cups shows that CT has the capacity for reliable measurement of linear wear of acetabular cups at a clinically relevant level of accuracy. PMID:21281259

Evaluation of late redislocation in patients who underwent open reduction and pelvic osteotomy as treament for developmental dysplasia of the hip.

PubMed

Tuhanioğlu, Ümit; Cicek, Hakan; Ogur, Hasan U; Seyfettinoglu, Firat; Kapukaya, Ahmet

2017-10-16

The goal in the treatment of developmental dysplasia of the hip (DDH) is to achieve a stable and concentric reduction and to create a congruent relationship between the femoral head and the acetabulum. This study discusses the causes of loss of reduction in DDH patients who had a concentrically reduced hip at the time of removal of the hip spica cast and cessation of brace use and who later appeared with hip redislocation after mobilisation and ambulation. In addition, the possible interventions in such cases are also discussed. A retrospective evaluation was made of 13 patients diagnosed with DDH who developed redislocation following primary surgery. 6 of them had undergone the 1st surgery in our department between 2008 and 2016 and 7 had udergone surgery in another centre. For comparison reasons a 2nd group was formed of 13 demographically and clinically matched patients who had no loss of reduction. The groups were compared in terms of acetabular index, pelvic length, pelvic width, abduction degree of plaster, ossifying nucleus diameter, acetabular depth, and acetabular volume parameters. The average age of the patients was 23 months at initial surgery and 29 months at the time of revision surgery. No significant difference was found between the groups in terms of acetabular inclination angle, ossifying nucleus diameter, pelvic size, pelvic width, centre edge angle, acetabular volume, and depth. Contracted inferomedial capsule was found in 1 patient who underwent revision surgery and intact transverse acetabular ligament was seen in 1 patient. The loss of reduction in the remaining 11 patients was associated with high total anteversion of the femoral head and acetabulum. Correction of increased combined anteversion by femoral osteotomy can create a safe zone in terms of redislocation and can significantly contribute to the stability provided by capsulorrhaphy and pelvic osteotomy.

Biochemical and Cellular Assessment of Acetabular Chondral Flaps Identified During Hip Arthroscopy.

PubMed

Hariri, Sanaz; Truntzer, Jeremy; Smith, Robert Lane; Safran, Marc R

2015-06-01

To analyze chondral flaps debrided during hip arthroscopy to determine their biochemical and cellular composition. Thirty-one full-thickness acetabular chondral flaps were collected during hip arthroscopy. Biochemical analysis was undertaken in 21 flaps from 20 patients, and cellular viability was determined in 10 flaps from 10 patients. Biochemical analysis included concentrations of (1) DNA (an indicator of chondrocyte content), (2) hydroxyproline (an indicator of collagen content), and (3) glycosaminoglycan (an indicator of chondrocyte biosynthesis). Higher values for these parameters indicated more healthy tissue. The flaps were examined to determine the percentage of viable chondrocytes. The percentage of acetabular chondral flap specimens that had concentrations within 1 SD of the mean values reported in previous normal cartilage studies was 38% for DNA, 0% for glycosaminoglycan, and 43% for hydroxyproline. The average cellular viability of our acetabular chondral flap specimens was 39% (SD, 14%). Only 2 of the 10 specimens had more than half the cells still viable. There was no correlation between (1) the gross examination of the joint or knowledge of the patient's demographic characteristics and symptoms and (2) biochemical properties and cell viability of the flap, with one exception: a degenerative appearance of the surrounding cartilage correlated with a higher hydroxyproline concentration. Although full-thickness acetabular chondral flaps can appear normal grossly, the biochemical properties and percentage of live chondrocytes in full-thickness chondral flaps encountered in hip arthroscopy show that this tissue is not normal. There has been recent interest in repairing chondral flaps encountered during hip arthroscopy. These data suggest that acetabular chondral flaps are not biochemically and cellularly normal. Although these flaps may still be valuable mechanically and/or as a scaffold in some conductive or inductive capacity, further study is required to assess the clinical benefit of repair. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

The use of an Ossis custom 3D-printed tri-flanged acetabular implant for major bone loss: minimum 2-year follow-up: Short title: Ossis custom 3D-Printed tri-flanged acetabular implant.

PubMed

Kieser, David C; Ailabouni, Ramez; Kieser, Sandra C J; Wyatt, Michael C; Armour, Paul C; Coates, Mark H; Hooper, Gary J

2018-05-01

Custom 3D-printed acetabular implants are a new technology used in hip surgery with ever-increasing frequency. They offer patient-specific implants to optimise filling of bone defects and implant-bone contact, without the need for excessive bone resection. This is a retrospective cohort study of 46 consecutive patients who underwent an Ossis unilateral custom 3D-printed acetabular implant. Clinical (Oxford Hip Score OHS-60), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Harris Hip Score (HHS) and radiological (restoration of biomechanical hip centre, osteointegration, wear, heterotrophic ossification) results were assessed. Patient mean age was 68 years and follow-up was 38 months (minimum 24 months). 10 patients were excluded from the outcome analysis; 2 patients died, 1 required revision for deep infection and 7 were lost to follow-up. Of the 36 patients included, 21 had severe osteolysis. 7 were revised for infection, 3 for tumoural defects, 3 for metallosis, 1 for dysplasia and 1 for trauma (Paprosky 2a [n=6], 2b [n=2], 2c [n=5], 3a [n=6], 3b [n=11], pelvic dissociation [n=6]). OHS significantly improved postoperatively (16-8-48.4 p=0.027). Postoperative functional scores were good (WOMAC 98; HHS 79). The biomechanical hip centre was restored in all patients. 1 patient had early implant migration with subsequent stabilisation. 2 patients had radiographs concerning for failure of osteointegration. 1 patient had recurrent dislocations. The mid-term results of the Ossis custom 3D-printed tri-flanged acetabular implant for the management of severe acetabular defects are encouraging. The improvement in functional scores and radiographic outcomes are comparable to similar designs. In addition, no cases have required revision for aseptic loosening.

[One-stage operation for pelvis and acetabular fractures combined with Morel-Lavallée injury by internal fixation associated with vacuum sealing drainage].

PubMed

Wei, Dan; Wang, Yue; Yuan, Jiabin; Tang, Xiaoming; Zhang, Bin; Lu, Bing; Tan, Bo

2014-01-01

To investigate the methods and effectiveness of one-stage operation for pelvis and acetabular fractures combined with Morel-Lavallée injury by internal fixation associated with vacuum sealing drainage (VSD). Between June 2008 and October 2012, 15 cases of pelvis and acetabular fractures combined with Morel-Lavallée injury were treated. There were 5 males and 10 females, aged from 18 to 67 years (mean, 36.8 years). Fractures were caused by traffic accident in 11 cases and crashing injury of heavy object in 4 cases. The time from injury to hospitalization was 3 hours to 9 days (mean, 5.4 days). Morel-Lavallée injury located in the above posterior superior iliac spine in 4 cases, greater trochanter in 7 cases, and anterior proximal thigh in 4 cases. In 10 cases complicated by pelvic fracture, there were 1 case of anteroposterior compression type, 3 cases of lateral compression type, 5 cases of vertical shear type, and 1 case of compound injury type; in 5 cases complicated by acetabular fracture, there were 1 case of transverse fracture, 1 case of posterior wall and posterior column fracture, 1 case of transverse acetabulum plus posterior wall fracture, and 2 cases of both columns fracture. Open reduction and internal fixation were used to treat pelvic and acetabular fractures, and VSD to treat Morel-Lavallée injury. When the drainage volume was less than 20 mL/d, interrupted wound suture or free skin grafting was performed. The hospitalization time was 16-31 days (mean, 20.8 days). Thirteen cases were followed up 4-16 months (mean, 7.8 months). The healing time of Morel-Lavallée injury was 16-36 days after operation (mean, 21.3 days). All the wounds had primary healing, and no infection occurred. The X-ray films showed that all fractures healed, with a mean healing time of 13.6 weeks (range, 11-18 weeks). At 6.5 months after operation, according to Majeed function scoring system in 8 cases of pelvic fracture, the results were excellent in 5 cases, good in 2 cases, and fair in 1 case; according to Harris hip scoring in 4 cases of acetabular fracture, the results were excellent in 2 cases, good in 1 case, and fair in 1 case. To pelvis-acetabular fractures combined with Morel-Lavallée injury, internal fixation treatment for fracture and VSD for Morel-Lavallée injury not only can cure merge Morel-Lavallée injury effectively, but also can guarantee the operation timing and incision safty of the pelvis-acetabular fractures.

Space orientation of total hip prosthesis. A method for three-dimensional determination.

PubMed

Herrlin, K; Selvik, G; Pettersson, H

1986-01-01

A method for in vivo determination of orientation and relation in space of components of total hip prosthesis is described. The method allows for determination of the orientation of the prosthetic components in well defined anatomic planes of the body. Furthermore the range of free motion from neutral position to the point of contact between the edge of the acetabular opening and the neck of the femoral component can be determined in various directions. To assess the accuracy of the calculations a phantom prosthesis was studied in nine different positions and the measurements of the space oriented parameters according to the present method correlated to measurements of the same parameters according to Selvik's stereophotogrammetric method. Good correlation was found. The role of prosthetic malpositioning and component interaction evaluated with the present method in the development of prosthetic loosening and displacement is discussed.

Estimation of appropriate lubricating film thickness in ceramic-on-ceramic hip prostheses

NASA Astrophysics Data System (ADS)

Tauviqirrahman, M.; Muchammad, Bayuseno, A. P.; Ismail, R.; Saputra, E.; Jamari, J.

2016-04-01

Artificial hip prostheses, consisting of femoral head and acetabular cup are widely used and have affected the lives of many people.However, the primary issue associated with the long term performance of hip prostheses is loosening induced by excessive wear during daily activity. Therefore, an effective lubrication is necessary to significantly decrease the wear. To help understand the lubricating performance of such typical hip joint prostheses, in the present paper a hydrodynamic lubrication model based on Reynolds equationwas introduced. The material pairs of ceramic acetabular cup against ceramic femoral head was investegated.The main aim of this study is to investigate of the effect of loading on the formation of lubricating film thickness.The model of a ball-in-socket configuration was considered assuming that the cup was stationary while the ball was to rotate at a steady angular velocityvarying loads.Based on simulation result, it was found that to promote fluid film lubrication and prevent the contacting components leading to wear, the film thickness of lubricant should be determined carefully based on the load applied. This finding may have useful implication in predicting the failure of lubricating synovial fluid film and wear generation in hip prostheses.

Kinematic alignment technique for total hip and knee arthroplasty

PubMed Central

Rivière, Charles; Lazic, Stefan; Villet, Loïc; Wiart, Yann; Allwood, Sarah Muirhead; Cobb, Justin

2018-01-01

Conventional techniques for hip and knee arthroplasty have led to good long-term clinical outcomes, but complications remain despite better surgical precision and improvements in implant design and quality. Technological improvements and a better understanding of joint kinematics have facilitated the progression to ‘personalized’ implant positioning (kinematic alignment) for total hip (THA) and knee (TKA) arthroplasty, the true value of which remains to be determined. By achieving a true knee resurfacing, the kinematic alignment (KA) technique for TKA aims at aligning the components with the physiological kinematic axes of the knee and restoring the constitutional tibio-femoral joint line frontal and axial orientation and soft-tissue laxity. The KA technique for THA aims at restoring the native ‘combined femoro-acetabular anteversion’ and the hip’s centre of rotation, and occasionally adjusting the cup position and design based on the assessment of the individual spine-hip relation. The key element for optimal prosthetic joint kinematics (hip or knee) is to reproduce the femoral anatomy. The transverse acetabular ligament (TAL) is the reference landmark to adjust the cup position. Cite this article: EFORT Open Rev 2018;3:98-105. DOI: 10.1302/2058-5241.3.170022 PMID:29657851

Morphometric assessment of hip dysplasia in a cat treated by juvenile pubic symphysiodesis.

PubMed

Lai, Alen; Culvenor, John; Bailey, Craig

2016-09-20

To quantitatively evaluate the change of the coxofemoral joints using computed tomography and distraction index in a cat with hip dysplasia treated by juvenile pubic symphysiodesis. Case report. Eighteen-week-old female entire Maine Coon cat. Juvenile pubic symphysiodesis resulted in changes in the distraction index, acetabular angle, dorsal acetabular rim angle, dorsal acetabular sector angle, and clinical improvement at the six month follow-up. No intra-operative or postoperative complications were recorded. Juvenile pubic symphysiodesis performed at 18 weeks of age resulted in improvement in hip joint conformation and hip laxity in a dysplastic cat. Juvenile pubic symphysiodesis may be a promising treatment for feline hip dysplasia and is a safe and technically simple procedure to perform. Further investigations are warranted.

Sex assessment from the acetabular rim by means of image analysis.

PubMed

Benazzi, S; Maestri, C; Parisini, S; Vecchi, F; Gruppioni, G

2008-08-25

Determining sex from skeletal remains is one of the most important steps in archaeological and forensic anthropology. The present study considers the diagnostic value of the acetabulum based on its planar image and related metric data. For this purpose, 83 adult os coxae of known age were examined. Digital photos of the acetabular area were taken, with each bone in a standardized orientation. Technical drawing software was used to trace the acetabular rim and to measure the related dimensions (area, perimeter, longitudinal and transverse maximum width). The measurements were subjected to SPSS discriminant and classification function analysis. There were significant differences (p

Hip and knee replacement in osteogenesis imperfecta.

PubMed

Papagelopoulos, P J; Morrey, B F

1993-04-01

Five total hip and three total knee arthroplasties were performed, from 1969 to 1990, in six patients who had osteogenesis imperfecta. The patients who had a hip arthroplasty were followed for a mean of seven years, and those who had a knee arthroplasty, for a mean of ten years. Postoperatively, all had relief of pain and were able to walk; one patient used a walker and two used a cane. The only postoperative complication was an intrapelvic protrusion of the acetabular component six years after a bipolar hip replacement.

Modular femoral component for conversion of previous hip surgery in total hip arthroplasty.

PubMed

Goldstein, Wayne M; Branson, Jill J

2005-09-01

The conversion of previous hip surgery to total hip arthroplasty creates a durable construct that is anatomically accurate. Most femoral components with either cemented or cementless design have a fixed tapered proximal shape. The proximal femoral anatomy is changed due to previous hip surgery for fixation of an intertrochanteric hip fracture, proximal femoral osteotomy, or a fibular allograft for avascular necrosis. The modular S-ROM (DePuy Orthopaedics Inc., Warsaw, Ind) hip stem accommodates these issues and independently prepares the proximal and distal portion of the femur. In preparation and implantation, the S-ROM hip stem creates less hoop stresses on potentially fragile stress risers from screws and thin bone. The S-ROM hip stem also prepares a previously distorted anatomy by milling through cortical bone that can occlude the femoral medullar canals and recreate proper femoral anteversion and reduces the risk of intraoperative or postoperative periprosthetic fracture due to the flexible titanium-slotted stem. The S-ROM femoral stem is recommended for challenging total hip reconstructions.

[A therapeutic effect analysis of femur first principle and combined anteversion technique during total hip arthroplasty].

PubMed

Wang, X Q; Wu, C S; Sun, S; Wang, J; Li, W; Zhang, W

2018-04-01

Objective: To investigate the situation of hip dislocation with the application of "femur first" principle and "combined anteversion technique" during total hip arthroplasty. Methods: A retrospective analysis has been done on the clinical data about 104 patients(133 hips)who were diagnosed as hip disease and were treated with total hip arthroplasty by the doctors from the Department of Joint Orthorpaedics of Shandong Provincial Hospital Affiliated to Shandong University from June 2014 to June 2016, and all the prostheses applied in the operation were cementless ones.Among them, 65 patients were males, 39 females and their age was 46.6 years (ranging from 23 to 76 years) .And 29 of them underwent bilateral hip operations and 75 unilateral ones.Seventy-six cases of aseptic necrosis of the femoral head in the terminal stage, 28 cases of hip dysplasia and osteoarthritis.Surgical approach: of all the operations, 103 hips were operated on with hardinge approach, 30 with posterolateral approach.During the operation, first of all, the femoral medullary cavity was broached and then the anteversion of intramedullary broacher was measured.After that, the anteversion of the acetabular cup was calculated as 37° minus the anteversion of the broacher, and the acetabular cup was implanted at that angle.The patients' prosthesis combined anteversion, range of motion of the hip joint, operation time, hemorrhage amount, and complications had been kept record.One, three, and six months respectively after the operation, all the patients received outpatient review, and took anteroposterior and lateral position X-ray examination.Harris hip score had been applied to evaluate their hip function before the operation and six months after the operation. Results: All the patients had been operated on smoothly, with the operation time of(57.6±14.5)minutes(36-115 minutes)and hemorrhage amount of (336.5±50.8)ml(180-620 ml). The operation finding showed that the combined anteversion by employing"femur first"principle and combined anteversion techniqueis was (36.6±6.8)°. Also, range of motion of the patients' hip conforms to the D'Lima criterion and no patients had experienced dislocation and some other serious complications.The follow-up ended at August 2017, which lasted for 12.2 months(6-18 months), and 88 cases(119 hips) were interviewed. The Harris hip score for the affected sides of the hip joints 6 months after the surgery was 94.6(86-100). Compared with the score of 29.8(12-43) before surgery, the t -test had proven its statistical significance( t =12.82, P =0.003). Conclusion: Based upon the "femoral first" principle and "combined anteversion technique" during total hip arthroplasty, these operations has been carried out well enough to meet the patients' needs of performing normal daily activities.

[On the history of cementless implants in extremity surgery].

PubMed

Dufek, Pavel

2017-05-01

The aim of implantation of cementless hip prostheses is vital ingrowth of bone into the structured metal surface of the implant. Since the 1960s several implants with surfaces made of cobalt-based alloys have been produced for this purpose. In the 1980s a novel hip endoprosthesis with a spongiosa-metal surface was introduced. The three-dimensional ingrowth of bone tissue into the structured surface of the implant could be demonstrated both histologically and using scanning electron microscopy (SEM). These implants made of cobalt-based alloys can also be used in endo-exo prostheses. Titanium implants with a microstructured surface have also been used and very good osseintegration of the surface was also demonstrated by histomorphology. The optimization of the surface and design of the prostheses plays an increasingly more important role in the field of revision endoprostheses.

Numeric simulation of bone remodelling patterns after implantation of a cementless straight stem.

PubMed

Lerch, Matthias; Windhagen, Henning; Stukenborg-Colsman, Christina M; Kurtz, Agnes; Behrens, Bernd A; Almohallami, Amer; Bouguecha, Anas

2013-12-01

For further development of better bone-preserving implants in total hip arthroplasty (THA), we need to look back and analyse established and clinically approved implants to find out what made them successful. Finite element analysis can help do this by simulating periprosthetic bone remodelling under different conditions. Our aim was thus to establish a numerical model of the cementless straight stem for which good long-term results have been obtained. We performed a numeric simulation of a cementless straight stem, which has been successfully used in its unaltered form since 1986/1987. We have 20 years of experience with this THA system and implanted it 555 times in 2012. We performed qualitative and quantitative validation using bone density data derived from a prospective dual-energy X-ray absorptiometry (DEXA) investigation. Bone mass loss converged to 9.25% for the entire femur. No change in bone density was calculated distal to the tip of the prosthesis. Bone mass decreased by 46.2% around the proximal half of the implant and by 7.6% in the diaphysis. The numeric model was in excellent agreement with DEXA data except for the calcar region, where deviation was 67.7%. The higher deviation in the calcar region is possibly a sign of the complex interactions between the titanium coating on the stem and the surrounding bone. We developed a validated numeric model to simulate bone remodelling for different stem-design modifications. We recommend that new THA implants undergo critical numeric simulation before clinical application.

The Proximal and Distal Femoral Canal Geometry Influences Cementless Stem Anchorage and Revision Hip and Knee Implant Stability.

PubMed

Heinecke, Markus; Rathje, Fabian; Layher, Frank; Matziolis, Georg

2018-05-01

Although cementless revision arthroplasty of the hip has become the gold standard, revision arthroplasty of the distal femur is controversial. This study evaluated the anchoring principles of different femoral revision stem designs in extended bone defect situations, taking into account the anatomical conditions of the proximal and distal femur, and the resulting primary stability. Cementless press-fit stems of 4 different designs were implanted in synthetic femurs. The specimens were analyzed by computed tomography and were tested considering axial/torsional stiffness and migration resistance. Different stem designs anchored in different femoral canal geometries achieved comparable primary stability. Despite considerably different anchorage lengths, no difference in migration behavior or stiffness was found. Both in the distal femur and in the proximal femur, the conical stems showed a combination of conical and 3-point anchorage. Regarding the cylindrical stem tested, a much shorter anchorage length was sufficient in the distal femur to achieve comparable primary stability. In the investigated osseous defect model, the stem design (conical vs cylindrical), not the geometry of the femoral canal (proximal vs distal), was decisive regarding the circumferential anchorage length. For the conical stems, it can be postulated that there are reserves available for achieving a conical-circular fixation as a result of the large contact length. For the cylindrical stems, only a small reserve for a stable anchorage can be assumed. [Orthopedics. 2018; 41(3):e369-e375.]. Copyright 2018, SLACK Incorporated.

Influence of different sizes of composite femora on the biomechanical behavior of cementless hip prosthesis.

PubMed

Schmidutz, Florian; Woiczinski, Mathias; Kistler, Manuel; Schröder, Christian; Jansson, Volkmar; Fottner, Andreas

2017-01-01

For the biomechanical evaluation of cementless stems different sizes of composite femurs have been used in the literature. However, the impact of different specimen sizes on test results is unknown. To determine the potential effect of femur size the biomechanical properties of a conventional stem (CLS Spotorno) were examined in 3 different sizes (small, medium and large composite Sawbones®). Primary stability was tested under physiologically adapted dynamic loading conditions measuring 3-dimensional micromotions. For the small composite femur the dynamic load needed to be adapted since fractures occurred when reaching 1700N. Additionally, surface strain distribution was recorded before and after implantation to draw conclusions about the tendency for stress shielding. All tested sizes revealed similar micromotions only reaching a significant different level at one measurement point. The highest micromotions were observed at the tip of the stems exceeding the limit for osseous integration of 150μm. Regarding strain distribution the highest strain reduction after implantation was registered in all sizes at the level of the lesser trochanter. Specimen size seems to be a minor influence factor for biomechanical evaluation of cementless stems. However, the small composite femur is less suitable for biomechanical testing since this size failed under physiological adapted loads. For the CLS Spotorno osseous integration is unlikely at the tip of the stem and the tendency for stress shielding is the highest at the level of the lesser trochanter. Copyright © 2016 Elsevier Ltd. All rights reserved.

10-year evaluation of the cementless low-contact- stress rotating-platform total knee arthroplasty.

PubMed

Efstathopoulos, Nikolaos; Mavrogenis, Andreas F; Lallos, Stergios; Nikolaou, Vassilios; Papagelopoulos, Panayiotis J; Savvidou, Olga D; Korres, Demetrios S

2009-01-01

We present the clinical and radiographic outcomes of the cementless low-contact-stress (LCS) rotating-platform total knee arthroplasty. Overall, 423 prostheses were implanted in 393 consecutive patients (30 patients had bilateral total knee replacement) for primary varus gonarthrosis (381 patients) and rheumatoid arthritis (12 patients). There were 81 men and 312 women with a mean age of 73 years (range, 58-85 years). Patella replacement was not performed in any case. Clinical and radiographic evaluation was performed using the Knee Society Score (KSS) and the Knee Society Assessment Form, respectively. The mean follow-up was 10 years (range, 5-15 years). Three patients were lost to follow-up. Survival of the prostheses was 98% at 10 years; three prostheses required revision for deep infection, bearing dislocation, and periprosthetic fracture. The mean KSS improved significantly, from 42 and 44 points preoperatively to 90 and 79 points, respectively, at the latest evaluation (P < 0.001); results were excellent in 278 cases, good in 106, fair in 27, and poor in nine. Radiolucent lines were observed in 80 cases; revision arthroplasty was not performed in any of these cases. Complications included deep infection in one patient, bearing dislocation in one, skin necrosis in four, and a supracondylar fracture in one. The cementless LCS rotating-platform total knee arthroplasty is associated with excellent mid- and long-term results for patients with osteoarthritis and rheumatoid arthritis of the knee.

Hip morphology predicts posterior hip impingement in a cadaveric model.

PubMed

Morris, William Z; Fowers, Cody A; Weinberg, Douglas S; Millis, Michael B; Tu, Leigh-Anne; Liu, Raymond W

2018-05-01

Posterior hip impingement is a recently-identified cause of hip pain. The purpose of this study is to characterise posterior femoroacetabular and ischiofemoral impingement and identify its predisposing morphologic traits. Two hundred and six cadaveric hips were randomly selected and taken through controlled motion in two pure axes associated with posterior hip impingement: external rotation (through the mechanical axis) and adduction (coronal plane). The range of motion and location of impingement was noted for each specimen. Morphologic traits including femoral/acetabular version, and true neck-shaft angle (TNSA) were also measured. External rotation impingement occurred between the femoral neck and acetabulum in 83.0% of hips, and between the lesser trochanter and ischial tuberosity in 17.0%. Adduction impingement occurred between the lesser trochanter and ischial tuberosity in 78.6% of hips, and between the femoral neck and acetabulum in 21.4%. Multiple regression revealed that increased femoral/acetabular version predicted earlier external rotation and adduction impingement. Unstandardised betas ranging from -0.39 to -0.64 reflect that each degree of increased femoral/acetabular version individually accounts for a loss of external rotation or adduction of approximately half a degree before impingement ( p < 0.001 for each). Increased TNSA was associated with earlier adduction impingement only (unstandardised beta -0.35, p = 0.005). Relative femoral/acetabular anteversion was associated with earlier posterior hip impingement. Coxa valga was associated with earlier adduction impingement, but protective against external rotation impingement. These findings highlight the importance of monitoring correction during femoral/acetabular osteotomies, as overcorrection of retroversion may predispose to earlier posterior impingement.

Reduced survival for uncemented compared to cemented total hip arthroplasty after operatively treated acetabular fractures.

PubMed

Clarke-Jenssen, John; Westberg, Marianne; Røise, Olav; Storeggen, Stein Arne Øvre; Bere, Tone; Silberg, Ingunn; Madsen, Jan Erik

2017-11-01

Post traumatic arthritis and avascular necrosis of the femoral head are common complications after operatively treated acetabular fractures. This may cause severe disabilities for the patient, necessitating a total hip arthroplasty. Even though an arthroplasty may provide good symptomatic relief, the long-term results are more uncertain and no consensus exists according to preferred prosthetic designs. With this cohort study, we aimed to investigate the medium to long term arthroplasty survival and clinical results of total hip arthroplasty after operatively treated acetabular fractures. We included 52 patients treated with a secondary total hip arthroplasty at a median of 2.4 (0.1-14.1) years after an operatively treated acetabular fracture. The median age was 54 (11-82) years. Cemented arthroplasty was used for 33 patients, 10 patients had an uncemented arthroplasty and 9 patients received a hybrid arthroplasty. Average follow up was 8.0 (SD 5.0) years. Ten-year revision free arthroplasty survival was 79%. Uncemented arthroplasties had a significantly worse 10-year survival of 57%. Arthroplasties performed at a centre without a pelvic fracture service also had a significantly worse 10-years survival of 51%. Cox regression showed similar results with an 8-fold increase in risk of revision for both uncemented arthroplasties and operations performed at a non-pelvic trauma centre. Total hip arthroplasty secondary to an operatively treated acetabular fracture provides good symptomatic relief. These patients are, however, complex cases and are probably best treated at specialist centres with both pelvic trauma surgeons and arthroplasty surgeons proficient in complex revisions present. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relationships among measurements obtained by use of computed tomography and radiography and scores of cartilage microdamage in hip joints with moderate to severe joint laxity of adult dogs.

PubMed

Lopez, Mandi J; Lewis, Brooke P; Swaab, Megan E; Markel, Mark D

2008-03-01

To evaluate correlations among measurements on radiographic and computed tomography (CT) images with articular cartilage microdamage in lax hip joints of dogs. 12 adult mixed-breed hounds. Pelvic CT and radiography were performed. Hip joints were harvested following euthanasia. Orthopedic Foundation for Animals (OFA) and PennHIP radiograph reports were obtained. Norberg angle (NA) and radiographic percentage femoral head coverage (RPC) were determined. Center-edge angle (CEA), horizontal toit externe angle (HTEA), ventral acetabular sector angle (VASA), dorsal acetabular sector angle (DASA), horizontal acetabular sector angle (HASA), acetabular index (AI), and CT percentage femoral head coverage (CPC) were measured on 2-dimensional CT images. Femoral head-acetabular shelf percentage was measured on sagittal 3-dimensional CT (SCT) and transverse 3-dimensional CT (TCT) images. Light microscopy was used to score joint cartilage. Relationships of OFA confirmation and PennHIP osteoarthritis scores with radiography, CT, and cartilage variables and relationships of cartilage scores with radiography and CT measurements were evaluated with Spearman rank correlations. Pearson correlation was used for relationships of distraction index (DI) with radiography, CT, and cartilage variables. Significant relationships included PennHIP osteoarthritis score with cartilage score, CEA, HTEA, DASA, AI, CPC, and TCT; OFA confirmation score with cartilage score, NA, RPC, CEA, HTEA, DASA, AI, CPC, and TCT; cartilage score with NA, RPC, CEA, HTEA, DASA, HASA, AI, and TCT; and DI with cartilage score, CEA, HTEA, DASA, HASA, AI, and CPC. CT appeared to be a valuable imaging modality for predicting cartilage microdamage in canine hip joints.

Early Versus Late Weight-Bearing Protocols for Surgically Managed Posterior Wall Acetabular Fractures.

PubMed

Heare, Austin; Kramer, Nicholas; Salib, Christopher; Mauffrey, Cyril

2017-07-01

Despite overall improved outcomes with open reduction and internal fixation of acetabular fractures, posterior wall fractures show disproportionately poor results. The effect of weight bearing on outcomes of fracture management has been investigated in many lower extremity fractures, but evidence-based recommendations in posterior wall acetabular fractures are lacking. The authors systematically reviewed the current literature to determine if a difference in outcome exists between early and late postoperative weight-bearing protocols for surgically managed posterior wall acetabular fractures. PubMed and MEDLINE were searched for posterior wall acetabular fracture studies that included weight-bearing protocols and Merle d'Aubigné functional scores. Twelve studies were identified. Each study was classified as either early or late weight bearing. Early weight bearing was defined as full, unrestricted weight bearing at or before 12 weeks postoperatively. Late weight bearing was defined as restricted weight bearing for greater than 12 weeks postoperatively. The 2 categories were then compared by functional score using a 2-tailed t test and by complication rate using chi-square analysis. Six studies (152 fractures) were placed in the early weight-bearing category. Six studies (302 fractures) were placed in the late weight-bearing category. No significant difference in Merle d'Aubigné functional scores was found between the 2 groups. No difference was found regarding heterotopic ossification, avascular necrosis, superficial infections, total infections, or osteoarthritis. This systematic review found no difference in functional outcome scores or complication rates between early and late weight-bearing protocols for surgically treated posterior wall fractures. [Orthopedics. 2017: 40(4):e652-e657.]. Copyright 2017, SLACK Incorporated.

Study of the three-dimensional orientation of the labrum: its relations with the osseous acetabular rim

PubMed Central

Bonneau, Noémie; Bouhallier, July; Baylac, Michel; Tardieu, Christine; Gagey, Olivier

2012-01-01

Understanding the three-dimensional orientation of the coxo-femoral joint remains a challenge as an accurate three-dimensional orientation ensure an efficient bipedal gait and posture. The quantification of the orientation of the acetabulum can be performed using the three-dimensional axis perpendicular to the plane that passes along the edge of the acetabular rim. However, the acetabular rim is not regular as an important indentation in the anterior rim was observed. An innovative cadaver study of the labrum was developed to shed light on the proper quantification of the three-dimensional orientation of the acetabulum. Dissections on 17 non-embalmed corpses were performed. Our results suggest that the acetabular rim is better represented by an anterior plane and a posterior plane rather than a single plane along the entire rim as it is currently assumed. The development of the socket from the Y-shaped cartilage was suggested to explain the different orientations in these anterior and posterior planes. The labrum forms a plane that takes an orientation in between the anterior and posterior parts of the acetabular rim, filling up inequalities of the bony rim. The vectors VL, VA2 and VP, representing the three-dimensional orientation of the labrum, the anterior rim and the posterior rim, are situated in a unique plane that appears biomechanically dependent. The three-dimensional orientation of the acetabulum is a fundamental parameter to understand the hip joint mechanism. Important applications for hip surgery and rehabilitation, as well as for physical anthropology, were discussed. PMID:22360458

A comparative study of indium-111 DTPA radionuclide and iothalamate meglumine roentgenographic arthrography in the evaluation of painful total hip arthroplasty

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maxon, H.R.; Schneider, H.J.; Hopson, C.N.

1989-08-01

Fifteen patients with painful total hip prostheses were referred for nuclear medicine and roentgenographic arthrography studies to exclude loosening of the acetabular and/or the femoral component. A new radioisotopic technique suitable for the evaluation of both components was developed using dual-isotope single-photon tomography with {sup 99m}technetium methylene diphosphonate bone imaging and indium-111 diethylenetriaminepentacetic acid arthrography. Thirteen of the 15 subjects were subsequently treated with additional surgery. The surgical findings were compared with the nuclear medicine and roentgenographic results. The overall diagnostic accuracy of both arthrographic procedures was approximately 80%, but the roentgenographic arthrogram was more sensitive and the radionuclide arthrogrammore » was more specific.« less

Basic considerations for determining the amount of press fit in acetabular cup endoprostheses as a function of the elastic bone behavior.

PubMed

Winter, Werner; Karl, Matthias

2014-10-01

Acetabular cup endoprostheses are frequently placed in pelvic bone, employing the mechanical principle of press fit. While a sufficiently stable bone-implant connection is desirable, deformation of the cup and fracture of the pelvis should be avoided. The goal of this work is to demonstrate the importance of the elastic properties of bone on the amount of press fit achievable in a specific situation. On the basis of previous work describing the relation between relative bone mineral density and relative elastic modulus for cortical and trabecular bone, mechanical equations were used for analyzing the press-fit loading situation of an acetabular cup. Additionally, a two-dimensional finite element model was used for visualizing the stress and strain situation in the host bone occurring as a consequence of implant insertion, as well as the effect of moment loads acting on the acetabular cup. Given the fact that oversizing the implant for a specific recipient site is the only clinical means of optimizing press fit, knowledge of the elastic properties of the host bone before implant selection would be beneficial. Such information could, for instance, be derived from intraoperative compressive testing of the host bone.

Comparable ultrasound measurements of ten anatomical specimens of infant hip joints by the methods of Graf and Terjesen.

PubMed

Falliner, A; Hahne, H J; Hedderich, J; Brossmann, J; Hassenpflug, J

2004-04-01

To define which sonographic section planes relative to the acetabular inlet plane will produce analyzable images with the methods of Graf and Terjesen. Anatomical specimens of infant hip joints were investigated in a water bath using the methods of Graf and Terjesen. Acetabular position was varied in defined increments with respect to the ultrasound beam. The alpha angles and the femoral head coverage (FHC) were measured. To obtain images analyzable by the two methods, the ultrasound beam had to intersect with the acetabular inlet plane at defined angles. The acetabular notch had to be anteriorly rotated from the ultrasound beam plane by at least 20 degrees. Beam entry within a 50 degrees sector posterior to the perpendicular on the inlet plane resulted in analyzable images. The stepwise multiple linear regression analysis showed that alpha angles and FHC were much affected by the coronal-plane transducer tilt. The fact that caudal tilts of the transducer are associated with reduced alpha angles and FHC values should be kept in mind in clinical ultrasound investigations. It is recommended that the transducer should be put on the greater trochanter perpendicular to the transverse axis of the body.

Assessment of acetabular retroversion following long term review of Salter's osteotomy.

PubMed

Robb, Curtis A; Datta, Amit; Nayeemuddin, Mohammed; Bache, Christopher E

2009-01-01

Salter's innominate osteotomy may predispose to anterior over-coverage of the acetabulum. Over cover or retroversion has been demonstrated to be a cause of hip pain, impingement and subsequent osteoarthritis. We reviewed the long-term follow up of seventeen skeletally mature hips in sixteen patients who had previously undergone a Salter's osteotomy in childhood. The Salter pelvic osteotomy was performed at a mean average age of 5 years and follow up at a mean average age of 20 years. Patients were assessed by clinical examination for signs of impingement, Harris Hip Score and pelvic radiograph. Acetabular version was evaluated by the relationship between anterior and posterior walls of the acetabulum using templates applied to the pelvic radiograph as described by Hefti. The median acetabular cover averaged 17 degrees of anteversion with 2 patients (12%) demonstrating retroversion, neither of whom, had signs of impingement on examination. The mean average Harris Hip Score was 85 indicating a good outcome at long-term follow-up. We believe acetabular remodelling may occur with age after Salter's innominate osteotomy and have found good results in patients after skeletal maturation. Fears of long-term anterior over-coverage and retroversion with this operation may be unfounded.

Postural correction reduces hip pain in adult with acetabular dysplasia: A case report.

PubMed

Lewis, Cara L; Khuu, Anne; Marinko, Lee N

2015-06-01

Developmental dysplasia of the hip is often diagnosed in infancy, but less severe cases of acetabular dysplasia are being detected in young active adults. The purpose of this case report is to present a non-surgical intervention for a 31-year-old female with mild acetabular dysplasia and an anterior acetabular labral tear. The patient presented with right anterior hip and groin pain, and she stood with the trunk swayed posterior to the pelvis (swayback posture). The hip pain was reproduced with the anterior impingement test. During gait, the patient maintained the swayback posture and reported 6/10 hip pain. Following correction of the patient's posture, the patient's pain rating was reduced to a 2/10 while walking. The patient was instructed to maintain the improved posture. At the 1 year follow-up, she demonstrated significantly improved posture in standing and walking. She had returned to recreational running and was generally pain-free. The patient demonstrated improvement on self-reported questionnaires for pain, function, and activity. These findings suggest that alteration of posture can have an immediate and lasting effect on hip pain in persons with structural abnormality and labral pathology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Postural correction reduces hip pain in adult with acetabular dysplasia: a case report

PubMed Central

Lewis, Cara L.; Khuu, Anne; Marinko, Lee

2015-01-01

Developmental dysplasia of the hip is often diagnosed in infancy, but less severe cases of acetabular dysplasia are being detected in young active adults. The purpose of this case report is to present a non-surgical intervention for a 31-year-old female with mild acetabular dysplasia and an anterior acetabular labral tear. The patient presented with right anterior hip and groin pain, and she stood with the trunk swayed posterior to the pelvis (swayback posture). The hip pain was reproduced with the anterior impingement test. During gait, the patient maintained the swayback posture and reported 6/10 hip pain. Following correction of the patient’s posture, the patient’s pain rating was reduced to a 2/10 while walking. The patient was instructed to maintain the improved posture. At the 1 year follow-up, she demonstrated significantly improved posture in standing and walking. She had returned to recreational running and was generally pain-free. The patient demonstrated improvement on self-reported questionnaires for pain, function and activity. These findings suggest that alteration of posture can have an immediate and lasting effect on hip pain in persons with structural abnormality and labral pathology. PMID:25731688

Minimally invasive and computer-navigated total hip arthroplasty: a qualitative and systematic review of the literature

PubMed Central

2010-01-01

Background Both minimally invasive surgery (MIS) and computer-assisted surgery (CAS) for total hip arthroplasty (THA) have gained popularity in recent years. We conducted a qualitative and systematic review to assess the effectiveness of MIS, CAS and computer-assisted MIS for THA. Methods An extensive computerised literature search of PubMed, Medline, Embase and OVIDSP was conducted. Both randomised clinical trials and controlled clinical trials on the effectiveness of MIS, CAS and computer-assisted MIS for THA were included. Methodological quality was independently assessed by two reviewers. Effect estimates were calculated and a best-evidence synthesis was performed. Results Four high-quality and 14 medium-quality studies with MIS THA as study contrast, and three high-quality and four medium-quality studies with CAS THA as study contrast were included. No studies with computer-assisted MIS for THA as study contrast were identified. Strong evidence was found for a decrease in operative time and intraoperative blood loss for MIS THA, with no difference in complication rates and risk for acetabular outliers. Strong evidence exists that there is no difference in physical functioning, measured either by questionnaires or by gait analysis. Moderate evidence was found for a shorter length of hospital stay after MIS THA. Conflicting evidence was found for a positive effect of MIS THA on pain in the early postoperative period, but that effect diminished after three months postoperatively. Strong evidence was found for an increase in operative time for CAS THA, and limited evidence was found for a decrease in intraoperative blood loss. Furthermore, strong evidence was found for no difference in complication rates, as well as for a significantly lower risk for acetabular outliers. Conclusions The results indicate that MIS THA is a safe surgical procedure, without increases in operative time, blood loss, operative complication rates and component malposition rates. However, the beneficial effect of MIS THA on functional recovery has to be proven. The results also indicate that CAS THA, though resulting in an increase in operative time, may have a positive effect on operative blood loss and operative complication rates. More importantly, the use of CAS results in better positioning of acetabular component of the prosthesis. PMID:20470443

Early migration characteristics of a 180° porous-coated cup with 1-mm press fit.

PubMed

Stihsen, Christoph; Rath, Christopher; Radl, Roman; Saalabian, Ali A; Materna, Wilfried; Rehak, Peter; Windhager, Reinhard

2013-05-01

Evaluation of early cup movement is an important diagnostic tool to predict the likelihood of long-term implant loosening and clinical failure. The investigated cementless cup is clinically proven over 10 years, but there is a paucity of information that accurately describes the migration characteristics of this component. We retrospectively analysed the clinical outcome and migration behaviour of 60 Pinnacle 100 shells after an average 3.8-year follow-up (range 2.1-5.4 years). For migration measurement, EBRA (Einzel-Bild-Röntgen-Analyse) digital software was applied. Clinical assessment was performed using the HHS, the UCLA score and the SF-36 health survey. The clinical outcome showed excellent results with a mean HHS of 95.4 (SD 7.1) and mean UCLA of 6.9 (SD 1.3). All implants were radiologically stable within the observation period and none of the cups was at risk for aseptical loosening. EBRA analysis revealed a mean total migration of 1.4 mm (SD 0.9) (95 % CI 1.1-1.6) at 3 years. Eight cups migrated more than 1 mm within the first three postoperative months, thereafter the migration curves flattened down. Surgeons may expect to find a variable amount of early migration when using the Pinnacle cup. To our knowledge, these are the first results, which show an early "impaction" of a cementless cup, followed by subsequent osseointegration. We believe that an appropriate long-term outcome of the investigated cup is ensured. The data of the present investigation will provide clinicians with useful baseline information with which to compare new cup designs.

Usefullness of three-dimensional templating software to quantify the contact state between implant and femur in total hip arthroplasty.

PubMed

Inoue, Daisuke; Kabata, Tamon; Maeda, Toru; Kajino, Yoshitomo; Fujita, Kenji; Hasegawa, Kazuhiro; Yamamoto, Takashi; Takagi, Tomoharu; Ohmori, Takaaki; Tsuchiya, Hiroyuki

2015-12-01

It would be ideal if surgeons could precisely confirm whether the planned femoral component achieves the best fit and fill of implant and femur. However, the cortico-cancellous interfaces can be difficult to standardize using plain radiography, and therefore, determining the contact state is a subjective decision by the examiner. Few reports have described the use of CT-based three-dimensional templating software to quantify the contact state of stem and femur in detail. The purpose of this study was to use three-dimensional templating software to quantify the implant-femur contact state and develop a technique to analyze the initial fixation pattern of a cementless femoral stem. We conducted a retrospective review of 55 hips in 53 patients using a short proximal fit-and-fill anatomical stem (APS Natural-Hip™ System). All femurs were examined by density mapping which can visualize and digitize the contact state. We evaluated the contact state of implant and femur by using density mapping. The varus group (cases that had changed varus 2° by 3 months after surgery) consisted of 11 hips. The varus group showed no significant difference with regard to cortical contact in the proximal medial portion (Gruen 7), but the contact area in the distal portion (Gruen 3 and Gruen 5) was significantly lower than that of non-varus group. Density mapping showed that the stem only has to be press-fit to the medial calcar, but also must fill the distal portion of the implant in order to achieve the ideal contact state. Our results indicated that quantifying the contact state of implant and femur by using density mapping is a useful technique to accurately analyze the fixation pattern of a cementless femoral stem.

Is there a rationale to use a dual mobility poly insert for failed Birmingham metal-on-metal hip replacements? A retrieval analysis.

PubMed

Renner, Lisa; Faschingbauer, Martin; Boettner, Friedrich

2015-08-01

Previous studies showed poor outcomes for patients undergoing revision of failed metal-on-metal total hip arthroplasty (MoM-THA) and resurfacing (RS) with an increased risk of dislocation. Dual mobility inserts are an option to retain the acetabular component and change the metal-on-metal bearing to plastic-on-metal. The current study analyzes the rationale for the off-label use of a dual mobility poly insert (MDM X3, Stryker, Mahwah, NJ) in a Birmingham metal shell (Smith & Nephew, Memphis, TN). Based on retrievals from the implant database the study compared the clearance between 20 BHR shells, 31 MDM poly inserts and 24 ADM acetabular components of different sizes. The radial clearance was calculated for each possible combination of implants [n = 81 (MDM/BHR) and n = 119 (MDM/ADM)]. An MDM mobile bearing poly insert in an ADM shell has an average clearance of 0.314 mm (SD 0.031) compared to 0.234 mm (SD 0.030) in a BHR shell (p < 0.01). The minimal clearance is 0.246 and 0.163 mm, respectively. 30.9 % of the MDM/BHR clearances were within the range of the MDM/ADM bearing and 88.9 % had a clearance of more than 0.2 mm. Clearances of the MDM poly insert in a BHR shell are reduced, and although the majority of combinations appear safe, the indication needs to be made on an individual base carefully considering alternative treatment options.

Mechanisms of plastic deformation in highly cross-linked UHMWPE for total hip components--the molecular physics viewpoint.

PubMed

Takahashi, Yasuhito; Shishido, Takaaki; Yamamoto, Kengo; Masaoka, Toshinori; Kubo, Kosuke; Tateiwa, Toshiyuki; Pezzotti, Giuseppe

2015-02-01

Plastic deformation is an unavoidable event in biomedical polymeric implants for load-bearing application during long-term in-vivo service life, which involves a mass transfer process, irreversible chain motion, and molecular reorganization. Deformation-induced microstructural alterations greatly affect mechanical properties and durability of implant devices. The present research focused on evaluating, from a molecular physics viewpoint, the impact of externally applied strain (or stress) in ultra-high molecular weight polyethylene (UHMWPE) prostheses, subjected to radiation cross-linking and subsequent remelting for application in total hip arthroplasty (THA). Two different types of commercial acetabular liners, which belong to the first-generation highly cross-linked UHMWPE (HXLPE), were investigated by means of confocal/polarized Raman microprobe spectroscopy. The amount of crystalline region and the spatial distribution of molecular chain orientation were quantitatively analyzed according to a combined theory including Raman selection rules for the polyethylene orthorhombic structure and the orientation distribution function (ODF) statistical approach. The structurally important finding was that pronounced recrystallization and molecular reorientation increasingly appeared in the near-surface regions of HXLPE liners with increasing the amount of plastic (compressive) deformation stored in the microstructure. Such molecular rearrangements, occurred in response to external strains, locally increase surface cross-shear (CS) stresses, which in turn trigger microscopic wear processes in HXLPE acetabular liners. Thus, on the basis of the results obtained at the molecular scale, we emphasize here the importance of minimizing the development of irrecoverable deformation strain in order to retain the pristine and intrinsically high wear performance of HXLPE components. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Safe Zone Range for Cup Anteversion Is Narrower Than for Inclination in THA.

PubMed

Murphy, William S; Yun, Ho Hyun; Hayden, Brett; Kowal, Jens H; Murphy, Stephen B

2018-02-01

Cup malposition is a common cause of impingement, limitation of ROM, acceleration of bearing wear, liner fracture, and instability in THA. Previous studies of the safe zone based on plain radiographs have limitations inherent to measuring angles from two-dimensional projections. The current study uses CT to measure component position in stable and unstable hips to assess the presence of a safe zone for cup position in THA. (1) Does acetabular component orientation, when measured on CT, differ in stable components and those revised for recurrent instability? (2) Do CT data support historic safe zone definitions for component orientation in THA? We identified 34 hips that had undergone revision of the acetabulum for recurrent instability that also had a CT scan of the pelvis between August 2003 and February 2017. We also identified 175 patients with stable hip replacements who also had a CT study for preoperative planning and intraoperative navigation of the contralateral side. For each CT study, one observer analyzed major factors including acetabular orientation, femoral anteversion, combined anteversion (the sum of femoral and anatomic anteversion), pelvic tilt, total offset difference, head diameter, age, sex, and body mass index. These measures were then compared among stable hips, hips with cup revision for anterior instability, and hips with cup revision for posterior instability. We used a clinically relevant measurement of operative anteversion and inclination as opposed to the historic use of radiographic anteversion and inclination. The percentage of unstable hips in the historic Lewinnek safe zone was calculated, and a new safe zone was proposed based on an area with no unstable hips. Anteriorly unstable hips compared with stable hips had higher operative anteversion of the cup (44° ± 12° versus 31° ± 11°, respectively; mean difference, 13°; 95% confidence interval [CI], 5°-21°; p = 0.003), tilt-adjusted operative anteversion of the cup (40° ± 6° versus 26° ± 10°, respectively; mean difference, 14°; 95% CI, 10°-18°; p < 0.001), and combined tilt-adjusted anteversion of the cup (64° ± 10° versus 54° ± 19°, respectively; mean difference, 10°; 95% CI, 1°-19°; p = 0.028). Posteriorly unstable hips compared with stable hips had lower operative anteversion of the cup (19° ± 15° versus 31° ± 11°, respectively; mean difference, -12°; 95% CI, -5° to -18°; p = 0.001), tilt-adjusted operative anteversion of the cup (19° ± 13° versus 26° ± 10°, respectively; mean difference, -8°; 95% CI, -14° to -2°; p = 0.014), pelvic tilt (0° ± 6° versus 4° ± 6°, respectively; mean difference, -4°; 95% CI, -7° to -1°; p = 0.007), and anatomic cup anteversion (25° ± 18° versus 34° ± 12°, respectively; mean difference, -9°; 95% CI, -1° to -17°; p = 0.033). Thirty-two percent of the unstable hips were located in the Lewinnek safe zone (11 of 34; 10 posterior dislocations, one anterior dislocation). In addition, a safe zone with no unstable hips was identified within 43° ± 12° of operative inclination and 31° ± 8° of tilt-adjusted operative anteversion. The current study supports the notion of a safe zone for acetabular component orientation based on CT. However, the results demonstrate that the historic Lewinnek safe zone is not a reliable predictor of future stability. Analysis of tilt-adjusted operative anteversion and operative inclination demonstrates a new safe zone where no hips were revised for recurrent instability that is narrower for tilt-adjusted operative anteversion than for operative inclination. Tilt-adjusted operative anteversion is significantly different between stable and unstable hips, and surgeons should therefore prioritize assessment of preoperative pelvic tilt and accurate placement in operative anteversion. With improvements in patient-specific cup orientation goals and acetabular component placement, further refinement of a safe zone with CT data may reduce the incidence of cup malposition and its associated complications. Level III, diagnostic study.

3D surgical printing and pre contoured plates for acetabular fractures.

PubMed

Chana-Rodríguez, Francisco; Mañanes, Rubén Pérez; Rojo-Manaute, José; Gil, Pablo; Martínez-Gómiz, José María; Vaquero-Martín, Javier

2016-11-01

We describe the methodical and possibilities of 3D surgical printing in preoperative planning of acetabular fractures showing a case of a 45-year-old with an associated transverse fracture of the left acetabulum with posterior wall fracture, with multiple fragments, and posterior ipsilateral hip dislocation, defending the do it your-self mode. Copyright © 2016 Elsevier Ltd. All rights reserved.

Combination acetabular radiofrequency ablation and cementoplasty using a navigational radiofrequency ablation device and ultrahigh viscosity cement: technical note.

PubMed

Wallace, Adam N; Huang, Ambrose J; Vaswani, Devin; Chang, Randy O; Jennings, Jack W

2016-03-01

Percutaneous radiofrequency ablation and cementoplasty is an alternative palliative therapy for painful metastases involving axial load-bearing bones. This technical report describes the use of a navigational radiofrequency probe to ablate acetabular metastases from an anterior approach followed by instillation of ultrahigh viscosity cement under CT-fluoroscopic guidance. The tumor ablation databases of two institutions were retrospectively reviewed to identify patients who underwent combination acetabular radiofrequency ablation and cementoplasty using the STAR Tumor Ablation and StabiliT Vertebral Augmentation Systems (DFINE; San Jose, CA). Pre-procedure acetabular tumor volume was measured on cross-sectional imaging. Pre- and post-procedure pain scores were measured using the Numeric Rating Scale (10-point scale) and compared. Partial pain improvement was categorically defined as ≥ 2-point pain score reduction. Patients were evaluated for evidence of immediate complications. Electronic medical records were reviewed for evidence of delayed complications. During the study period, 12 patients with acetabular metastases were treated. The median tumor volume was 54.3 mL (range, 28.3-109.8 mL). Pre- and post-procedure pain scores were obtained from 92% (11/12) of the cohort. The median pre-procedure pain score was 8 (range, 3-10). Post-procedure pain scores were obtained 7 days (82%; 9/11), 11 days (9.1%; 1/11) or 21 days (9.1%; 1/11) after treatment. The median post-treatment pain score was 3 (range, 1-8), a statistically significant difference compared with pre-treatment (P = 0.002). Categorically, 73% (8/11) of patients reported partial pain relief after treatment. No immediate symptomatic complications occurred. Three patients (25%; 3/12) were discharged to hospice within 1 week of treatment. No delayed complications occurred in the remaining 75% (9/12) of patients during median clinical follow-up of 62 days (range, 14-178 days). Palliative percutaneous acetabular radiofrequency ablation and cementoplasty can be feasibly performed from an anterior approach using a navigational ablation probe and ultrahigh viscosity cement instilled under CT-fluoroscopic guidance.

Bony morphology of the hip in professional ballet dancers compared to athletes.

PubMed

Mayes, Susan; Ferris, April-Rose; Smith, Peter; Garnham, Andrew; Cook, Jill

2017-07-01

To compare hip bony morphology between ballet dancers and a sporting control group and to determine the relationship with hip pain. Thirty-three professional ballet dancers and 33 age- and sex-matched athletes completed questionnaires, including the Copenhagen Hip and Groin Outcome Score (HAGOS), and underwent clinical testing and 3.0-T magnetic resonance imaging to measure acetabular coverage with lateral centre edge angles, femoral head-neck junction concavity with alpha angles at anterior and superior positions, femoral neck-shaft angles, and acetabular version angles. Bony morphological measures fell within normal ranges. Dancers had higher neck-shaft angles (dancers 134.6 ± 4.6°/athletes130.8 ± 4.7°, p = 0.002), lower acetabular version angles (13.5 ± 4.7°/17.1 ± 4.7°, p = 0.003), lower superior alpha angles (38.9 ± 6.9°/46.7 ± 10.6°, p < 0.001), similar anterior alpha angles (43.6 ± 8.1/46 ± 7°, p = 0.2), and similar lateral centre edge angles (28.8 ± 4.6°/30.8 ± 4.5°, p = 0.07) compared to athletes. Abnormal morphology was detected in dancers: 3% acetabular dysplasia (athletes 0), 15% borderline dysplasia (6%), 24% cam morphology (33%), 24% coxa valga (6%), and 21% acetabular retroversion (18%). The HAGOS pain scores correlated moderately with acetabular version (r = -0.43, p = 0.02) in dancers, with no other correlation between pain and morphological parameters in either group. Professional ballet dancers have hip bony morphology that differentiates them from athletes. Hip pain correlated poorly with bony morphology. • Ballet dancers have hip bony morphology that may allow extreme hip motion. • Morphological parameter means fell within normal reference intervals in dancers. • Bony morphology correlates poorly with hip pain. • The risk of hip injury due to abnormal morphology requires prospective studies.

T2* Mapping Provides Information That Is Statistically Comparable to an Arthroscopic Evaluation of Acetabular Cartilage.

PubMed

Morgan, Patrick; Nissi, Mikko J; Hughes, John; Mortazavi, Shabnam; Ellerman, Jutta

2017-07-01

Objectives The purpose of this study was to validate T2* mapping as an objective, noninvasive method for the prediction of acetabular cartilage damage. Methods This is the second step in the validation of T2*. In a previous study, we established a quantitative predictive model for identifying and grading acetabular cartilage damage. In this study, the model was applied to a second cohort of 27 consecutive hips to validate the model. A clinical 3.0-T imaging protocol with T2* mapping was used. Acetabular regions of interest (ROI) were identified on magnetic resonance and graded using the previously established model. Each ROI was then graded in a blinded fashion by arthroscopy. Accurate surgical location of ROIs was facilitated with a 2-dimensional map projection of the acetabulum. A total of 459 ROIs were studied. Results When T2* mapping and arthroscopic assessment were compared, 82% of ROIs were within 1 Beck group (of a total 6 possible) and 32% of ROIs were classified identically. Disease prediction based on receiver operating characteristic curve analysis demonstrated a sensitivity of 0.713 and a specificity of 0.804. Model stability evaluation required no significant changes to the predictive model produced in the initial study. Conclusions These results validate that T2* mapping provides statistically comparable information regarding acetabular cartilage when compared to arthroscopy. In contrast to arthroscopy, T2* mapping is quantitative, noninvasive, and can be used in follow-up. Unlike research quantitative magnetic resonance protocols, T2* takes little time and does not require a contrast agent. This may facilitate its use in the clinical sphere.

Direct and indirect costs of surgically treated pelvic fractures.

PubMed

Aprato, Alessandro; Joeris, Alexander; Tosto, Ferdinando; Kalampoki, Vasiliki; Stucchi, Alessandro; Massè, Alessandro

2016-03-01

Pelvic fractures requiring surgical fixation are rare injuries but present a great societal impact in terms of disability, as well as economic resources. In the literature, there is no description of these costs. Main aim of this study is to describe the direct and indirect costs of these fractures. Secondary aims were to test if the type of fracture (pelvic ring injury or acetabular fracture) influences these costs (hospitalization, consultation, medication, physiotherapy sessions, job absenteeism). We performed a retrospective study on patients with surgically treated acetabular fractures or pelvic ring injuries. Medical records were reviewed in terms of demographic data, follow-up, diagnosis (according to Letournel and Tile classifications for acetabular and pelvic fractures, respectively) and type of surgical treatment. Patients were interviewed about hospitalization length, consultations after discharge, medications, physiotherapy sessions and absenteeism. The study comprised 203 patients, with a mean age of 49.1 ± 15.6 years, who had undergone surgery for an acetabular fracture or pelvic ring injury. The median treatment costs were 29.425 Euros per patient. Sixty percent of the total costs were attributed to health-related work absence. Median costs (in Euros) were 2.767 for hospitalization from trauma to definitive surgery, 4.530 for surgery, 3.018 for hospitalization in the surgical unit, 1.693 for hospitalization in the rehabilitation unit, 1.920 for physiotherapy after discharge and 402 for consultations after discharge. Total costs for treating pelvic ring injuries were higher than for acetabular fractures, mainly due to the significant higher costs of pelvic injuries regarding hospitalization from trauma to definitive surgery (p < 0.001) and hospitalization in the surgical unit (p = 0.008). Pelvic fractures are associated with both high direct costs and substantial productivity loss.

Application of an innovative computerized virtual planning system in acetabular fracture surgery: A feasibility study.

PubMed

Wang, Huixiang; Wang, Fang; Newman, Simon; Lin, Yanping; Chen, Xiaojun; Xu, Lu; Wang, Qiugen

2016-08-01

Acetabular fracture surgery is amongst the most challenging tasks in the field of trauma surgery and careful preoperative planning is crucial for success. The aim of this paper is to describe the preliminary outcome of the utilization of an innovative computerized virtual planning system for acetabular fractures. 3D models of acetabular fractures and surrounding soft tissues from six patients were constructed from preoperative CT scans. A novel highly-automatic segmentation technique was performed on the 3D model to separate each fracture fragment, then 3D virtual reduction was performed. Additionally, the models were used to assess potential surgical approaches with reference to both the fracture and the surrounding soft tissues. The time required for virtual planning was recorded. After surgery, the virtual plan was compared to the real surgery with respect to surgical approach and reduction sequence. A Likert scale questionnaire was completed by the surgeons to evaluate their satisfaction with the system. Virtual planning was successfully completed in all cases. The planned surgical approach was followed in all cases with the planned reduction sequence followed completely in five cases and partially in one. The mean time required for virtual planning was 38.7min (range 21-57, SD=15.5). The mean time required for planning of B-type fractures was 25.0min (range 21-30, SD=4.6), of C-type fracture 52.3min (range 49-57, SD=4.2). The results of the questionnaire demonstrated a high level of satisfaction with the planning system. This study demonstrates that the virtual planning system is feasible in clinical settings with high satisfaction and acceptability from the surgeons. It provides a viable option for the planning of acetabular fracture surgery. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative study of comminuted posterior acetabular wall fracture treated with the Acetabular Tridimensional Memory Fixation System.

PubMed

Zhang, Yuntong; Zhao, Xue; Tang, Yang; Zhang, Chuncai; Xu, Shuogui; Xie, Yang

2014-04-01

Posterior wall fractures are one of the most common acetabular fractures. However, only 30% of these fractures involve a single large fragment, and comminuted acetabular posterior wall fractures pose a particular surgical challenge. The purpose of this study was to compare outcomes between patients who received fixation for comminuted posterior wall fracture using the Acetabular Tridimensional Memory Fixation System (ATMFS) and patients who underwent fixation with conventional screws and buttress plates (Plates group). Between April 2003 and May 2007, 196 consecutive patients who sustained a comminuted posterior wall fracture of acetabulum were treated with ATMFS or conventional screws and buttress plates. Operative time, fluoroscopy time, blood loss, and any intra-operative complications were recorded. Plain AP and lateral radiographs were obtained at all visits (Matta's criteria). Modified Merle d' Aubigne-Postel score, and Mos SF-36 score were compared between groups. Fifty patients were included in the analysis with 26 in the ATMFS group and 24 in the Plates group. The mean follow-up time was 57.5 months, ranging from 31 to 69 months. All patients had fully healed fractures at the final follow-up. There was no difference in clinical outcomes or radiological evaluations between groups. Patients with comminuted posterior wall fractures of the acetabulum treated with the ATMFS or conventional screws and buttress plate techniques achieve a good surgical result. Both techniques are safe, reliable, and practical. Use of the ATMFS technique may reduce blood loss and improve rigid support to marginal bone impaction. The use ATMFS may need additional support when fractures involve the superior roof. Copyright © 2013 Elsevier Ltd. All rights reserved.

Morphometric analysis of acetabular dysplasia in cerebral palsy: three-dimensional CT study.

PubMed

Gose, Shinichi; Sakai, Takashi; Shibata, Toru; Murase, Tsuyoshi; Yoshikawa, Hideki; Sugamoto, Kazuomi

2009-12-01

Three-dimensional computed tomography (3D-CT) eliminates the positioning errors and allows the clinician to more accurately assess the radiographic parameters present. To elucidate the 3D geometry of the acetabulum and the extent of hip subluxation/dislocation in patients with cerebral palsy (CP), quantitative morphometric analysis was performed using 3D-CT data. We evaluated 150 hips in 75 patients with bilateral spastic CP. The mean age of the patients was 5.4 years (range: 2.7 to 6.9 y). The fitting plane of the ilium was projected onto the coronal plane and then onto the sagittal plane, and then the angle formed with a horizontal line was defined as CTalpha (the lateral opening angle) and CTbeta (the sagittal inclination angle), respectively. The center of the acetabulum and the femoral head were defined, and the distance between these centers was divided by the femoral head diameter, defined as CT migration percentage (CTMP, %). In 123 (82%) of the 150 hips, the femoral head center was located posteriorly, superiorly, and laterally relative to the acetabular center. Large CTalpha cases tended to show large CTMP. CTalpha and CTMP were significantly larger in the cases with Gross Motor Functional Classification System (GMFCS) level IV/V and spastic quadriplegia, than in the cases with GMFCS level II/III and spastic diplegia. CTbeta showed significant correlation with the acetabular defect on the lateral 3D reconstructed images. Three-dimensional acetabular geometry and migration percentage in CP patients can be analyzed quantitatively using 3D-CT regardless of the abnormal spastic posture. The extent of acetabular dysplasia and subluxation is more severe in patients with GMFCS level IV/V and spastic quadriplesia. Level 4.

Delivery of Antibiotics from Cementless Titanium-Alloy Cubes May Be a Novel Way to Control Postoperative Infections

PubMed Central

Bezuidenhout, Martin B.; van Staden, Anton D.; Oosthuizen, Gert A.; Dimitrov, Dimitar M.; Dicks, Leon M. T.

2015-01-01

Bacterial colonisation and biofilm formation onto orthopaedic devices are difficult to eradicate. In most cases infection is treated by surgical removal of the implant and cleaning of the infected area, followed by extensive treatment with broad-spectrum antibiotics. Such treatment causes great discomfort, is expensive, and is not always successful. In this study we report on the release of vancomycin through polyethersulfone membranes from channels in cementless titanium-alloy cubes. The cubes were constructed with LaserCUSING from Ti6Al4V ELI powder. Vancomycin was released by non-Fickian anomalous (constraint) diffusion. Approximately 50% of the vancomycin was released within the first 17 h. However, sustained delivery of vancomycin for 100 h was possible by reinjecting the channels. Refillable implants may be a novel way to control postoperative infections. PMID:25861649

Management of an infected cementless cup with prosthetic retention and antibiotic therapy in a dog.

PubMed

Dan, B J; Kim, S E; Pozzi, A

2014-11-01

A two-year-old Rottweiler presented for acute onset of a right hindlimb lameness 20 weeks after a cementless total hip replacement (THR) and 16 weeks after open reduction to address luxation of the THR. Radiographs revealed periosteal proliferation of the medial acetabulum and a stable implant. Synovial fluid cytology was consistent with inflammatory joint fluid. Treatment consisted of surgical debridement and intravenous and oral antibiotics. THR implants were not removed. Culture of tissue removed from the THR site yielded growth of Pseudomonas and Staphylococcus species. Lameness resolved 2 months after surgery. Twenty months after surgery, the dog was exercising normally with no clinical lameness and pelvic radiographs revealed no evidence of implant loosening and markedly decreased periosteal reaction. To the authors' knowledge, this is the first report of an infected THR site successfully treated without prosthesis explantation in the dog. © 2014 British Small Animal Veterinary Association.

Corrosion on the acetabular liner taper from retrieved modular metal-on-metal total hip replacements.

PubMed

Gascoyne, Trevor C; Dyrkacz, Richard M; Turgeon, Thomas R; Burnell, Colin D; Wyss, Urs P; Brandt, Jan-M

2014-10-01

Eight retrieved metal-on-metal total hip replacements displayed corrosion damage along the cobalt-chromium alloy liner taper junction with the Ti alloy acetabular shell. Scanning electron microscopy indicated the primary mechanism of corrosion to be grain boundary and associated crevice corrosion, which was likely accelerated through mechanical micromotion and galvanic corrosion resulting from dissimilar alloys. Coordinate measurements revealed up to 4.3mm(3) of the cobalt-chromium alloy taper surface was removed due to corrosion, which is comparable to previous reports of corrosion damage on head-neck tapers. The acetabular liner-shell taper appears to be an additional source of metal corrosion products in modular total hip replacements. Patients with these prostheses should be closely monitored for signs of adverse reaction towards corrosion by-products. Copyright © 2014 Elsevier Inc. All rights reserved.

Fixation strength analysis of cup to bone material using finite element simulation

NASA Astrophysics Data System (ADS)

Anwar, Iwan Budiwan; Saputra, Eko; Ismail, Rifky; Jamari, J.; van der Heide, Emile

2016-04-01

Fixation of acetabular cup to bone material is an important initial stability for artificial hip joint. In general, the fixation in cement less-type acetabular cup uses press-fit and screw methods. These methods can be applied alone or together. Based on literature survey, the additional screw inside of cup is effective; however, it has little effect in whole fixation. Therefore, an acetabular cup with good fixation, easy manufacture and easy installation is required. This paper is aiming at evaluating and proposing a new cup fixation design. To prove the strength of the present cup fixation design, the finite element simulation of three dimensional cup with new fixation design was performed. The present cup design was examined with twist axial and radial rotation. Results showed that the proposed cup design was better than the general version.

An in vitro simulation model to assess the severity of edge loading and wear, due to variations in component positioning in hip joint replacements.

PubMed

O'Dwyer Lancaster-Jones, O; Williams, S; Jennings, L M; Thompson, J; Isaac, G H; Fisher, J; Al-Hajjar, M

2017-09-23

The aim of this study was to develop a preclinical in vitro method to predict the occurrence and severity of edge loading condition associated with the dynamic separation of the centres of the head and cup (in the absence of impingement) for variations in surgical positioning of the cup. Specifically, this study investigated the effect of both the variations in the medial-lateral translational mismatch between the centres of the femoral head and acetabular cup and the variations in the cup inclination angles on the occurrence and magnitude of the dynamic separation, the severity of edge loading, and the wear rate of ceramic-on-ceramic hip replacement bearings in a multi-station hip joint simulator during a walking gait cycle. An increased mismatch between the centres of rotation of the femoral head and acetabular cup resulted in an increased level of dynamic separation and an increase in the severity of edge loading condition which led to increased wear rate in ceramic-on-ceramic bearings. Additionally for a given translational mismatch, an increase in the cup inclination angle gave rise to increased dynamic separation, worst edge loading conditions, and increased wear. To reduce the occurrence and severity of edge loading, the relative positions (the mismatch) of the centres of rotation of the head and the cup should be considered alongside the rotational position of the acetabular cup. This study has considered the combination of mechanical and tribological factors for the first time in the medial-lateral axis only, involving one rotational angle (inclination) and one translational mismatch. © 2017 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc.

The effect of cup outer sizes on the contact mechanics and cement fixation of cemented total hip replacements.

PubMed

Hua, Xijin; Li, Junyan; Wang, Ling; Wilcox, Ruth; Fisher, John; Jin, Zhongmin

2015-10-01

One important loosening mechanism of the cemented total hip arthroplasty is the mechanical overload at the bone-cement interface and consequent failure of the cement fixation. Clinical studies have revealed that the outer diameter of the acetabular component is a key factor in influencing aseptic loosening of the hip arthroplasty. The aim of the present study was to investigate the influence of the cup outer diameter on the contact mechanics and cement fixation of a cemented total hip replacement (THR) with different wear penetration depths and under different cup inclination angles using finite element (FE) method. A three-dimensional FE model was developed based on a typical Charnley hip prosthesis. Two acetabular cup designs with outer diameters of 40 and 43 mm were modelled and the effect of cup outer diameter, penetration depth and cup inclination angle on the contact mechanics and cement fixation stresses in the cemented THR were studied. The results showed that for all penetration depths and cup inclination angles considered, the contact mechanics in terms of peak von Mises stress in the acetabular cup and peak contact pressure at the bearing surface for the two cup designs were similar (within 5%). However, the peak von Mises stress, the peak maximum principal stress and peak shear stress in the cement mantle at the bone-cement interface for the 43 mm diameter cup design were predicted to be lower compared to those for the 40 mm diameter cup design. The differences were predicted to be 15-19%, 15-22% and 18-20% respectively for different cup penetration depths and inclination angles, which compares to the clinical difference of aseptic loosening incidence of about 20% between the two cup designs. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Mechanobiological simulations of peri-acetabular bone ingrowth: a comparative analysis of cell-phenotype specific and phenomenological algorithms.

PubMed

Mukherjee, Kaushik; Gupta, Sanjay

2017-03-01

Several mechanobiology algorithms have been employed to simulate bone ingrowth around porous coated implants. However, there is a scarcity of quantitative comparison between the efficacies of commonly used mechanoregulatory algorithms. The objectives of this study are: (1) to predict peri-acetabular bone ingrowth using cell-phenotype specific algorithm and to compare these predictions with those obtained using phenomenological algorithm and (2) to investigate the influences of cellular parameters on bone ingrowth. The variation in host bone material property and interfacial micromotion of the implanted pelvis were mapped onto the microscale model of implant-bone interface. An overall variation of 17-88 % in peri-acetabular bone ingrowth was observed. Despite differences in predicted tissue differentiation patterns during the initial period, both the algorithms predicted similar spatial distribution of neo-tissue layer, after attainment of equilibrium. Results indicated that phenomenological algorithm, being computationally faster than the cell-phenotype specific algorithm, might be used to predict peri-prosthetic bone ingrowth. The cell-phenotype specific algorithm, however, was found to be useful in numerically investigating the influence of alterations in cellular activities on bone ingrowth, owing to biologically related factors. Amongst the host of cellular activities, matrix production rate of bone tissue was found to have predominant influence on peri-acetabular bone ingrowth.

The developing juvenile ischium: macro-radiographic insights.

PubMed

Maclean, Stephen J; Black, Sue M; Cunningham, Craig A

2014-09-01

Despite the importance of the human pelvis as a weight-bearing structure, there is a paucity of literature that discusses the development of the juvenile innominate from a biomechanical perspective. This study aims to add to the limited body of literature pertaining to this topic through the qualitative analysis of the gross architecture of the human ischium during the juvenile period. Macro-radiographs of 55 human ischia ranging from 28 intra-uterine weeks to 14 years of age were examined using intensity-gradient color mapping to highlight changes in gross structural morphology with increasing age. A clear pattern of maturation was observed in the juvenile ischium with increasing age. The acetabular component and ramus of the ischium consistently displayed low bone intensity in the postnatal skeletal material. Conversely the posterior body of the ischium, and in particular the ischial spine and lesser sciatic notch, exhibited increasing bone intensity which first arose at 1-2 years of age and became more expansive in older cohorts. The intensity patterns observed within the developing juvenile ischium are indicative of the potential factors influencing the maturation of this skeletal element. While the low intensity acetabular fossa indicates a lack of significant biomechanical interactions, the posterior increase in bone intensity may be related to the load-bearing nature of the posterior ischium. © 2014 Wiley Periodicals, Inc.

Mesh morphing for finite element analysis of implant positioning in cementless total hip replacements.

PubMed

Bah, Mamadou T; Nair, Prasanth B; Browne, Martin

2009-12-01

Finite element (FE) analysis of the effect of implant positioning on the performance of cementless total hip replacements (THRs) requires the generation of multiple meshes to account for positioning variability. This process can be labour intensive and time consuming as CAD operations are needed each time a specific orientation is to be analysed. In the present work, a mesh morphing technique is developed to automate the model generation process. The volume mesh of a baseline femur with the implant in a nominal position is deformed as the prosthesis location is varied. A virtual deformation field, obtained by solving a linear elasticity problem with appropriate boundary conditions, is applied. The effectiveness of the technique is evaluated using two metrics: the percentages of morphed elements exceeding an aspect ratio of 20 and an angle of 165 degrees between the adjacent edges of each tetrahedron. Results show that for 100 different implant positions, the first and second metrics never exceed 3% and 3.5%, respectively. To further validate the proposed technique, FE contact analyses are conducted using three selected morphed models to predict the strain distribution in the bone and the implant micromotion under joint and muscle loading. The entire bone strain distribution is well captured and both percentages of bone volume with strain exceeding 0.7% and bone average strains are accurately computed. The results generated from the morphed mesh models correlate well with those for models generated from scratch, increasing confidence in the methodology. This morphing technique forms an accurate and efficient basis for FE based implant orientation and stability analysis of cementless hip replacements.

Ibandronate and cementless total hip arthroplasty: densitometric measurement of periprosthetic bone mass and new therapeutic approach to the prevention of aseptic loosening

PubMed Central

Muratore, Maurizio; Quarta, Eugenio; Quarta, Laura; Calcagnile, Fabio; Grimaldi, Antonella; Orgiani, M. Antonio; Marsilio, Antonio; Rollo, Giuseppe

2012-01-01

Summary Studies of the mechanisms of periprosthetic bone loss have led to the development of pharmacologic strategies intended to enhance bone mass recovery after surgery and consequently prevent aseptic loosening and prolong the implant survival. Bisphosphonates, potent anti-resorptive drugs widely used in the treatment of osteoporosis and other disorders of bone metabolism, were shown to be particularly effective in reducing periprosthetic bone resorption in the first year after hip and knee arthroplasty, both cemented and cementless. Based on these results, we investigated the inhibitory effects of ibandronate on periprosthetic bone loss in a 2-year study of postmenopausal women that underwent cementless total hip arthroplasty. In the first 6 months both groups (A, treated with ibandronate 3 mg i.v. within five days after surgery and then with oral ibandronate 150 mg/month, plus calcium and vitamin D supplementation; and B, treated with calcium and vitamin D supplementation only) experienced bone loss, though to a lesser extent in group A. After 12 months, group A showed a remarkable BMD recovery, that was statistically significant versus baseline values (about +1, 74% of global BMD) and most evident in region R1 (+3, 81%) and R2 (+4, 12%); in group B, on the contrary, BMD values were unchanged compared with those at 6 months post-surgery. Quality of life scores also showed a greater improvement in group A, both at 6 and 12 months after surgery, likely because of the pain-reducing effects of ibandronate treatment. PMID:22783337

A femoral component inserted without cement in total hip arthroplasty. A study of the Tri-Lock component with an average ten-year duration of follow-up.

PubMed

Burt, C F; Garvin, K L; Otterberg, E T; Jardon, O M

1998-07-01

Seventy-four total hip arthroplasties in sixty-six patients were performed, between 1983 and 1986, with use of a Tri-Lock femoral component inserted without cement. This tapered cobalt-chromium component has a fixed head and a circumferential proximal porous coating. Follow-up was conducted with use of a questionnaire, physical examination, and radiographic analysis. At the time of the latest follow-up, fifteen patients (eighteen hips) had died, three patients (four hips) had been lost to follow-up, and one patient (one hip) had refused to participate in the follow-up study; however, the status of fifteen hips at the time of death could be verified. Thus, clinical follow-up data were available for sixty-six of the original seventy-four hips. The average age at the time of the operation was sixty-two years (range, seventeen to eighty-four years), and the average interval between the operation and the latest follow-up evaluation was 10.0 years (range, 8.3 to 11.6 years). The Harris hip score was determined for forty-three hips (forty-one patients) in which the prosthesis was in situ at the time of the latest follow-up. The score was good for thirteen hips and excellent for twenty-eight, so the rate of clinical success was 95 per cent. Two patients had a fair result. One of them had persistent pain and the other had limited motion, but neither had radiographic evidence of loosening of the femoral or acetabular component. All forty-one patients were satisfied with the result. The probability (with standard error) of survival of the femoral component at ten years, with revision as the end point, was 0.95 +/- 0.03. The rate of revision of the femoral component because of aseptic loosening was one (2 per cent) of sixty-six. The overall rate of aseptic loosening of the femoral component in the hips that were followed radiographically was two (4 per cent) of forty-seven. Only one (2 per cent) of the forty-seven acetabular cups had evidence of aseptic loosening. There was no radiographic evidence of distal osteolysis around the prostheses that were well fixed. Proximal osteolysis was present in five (11 per cent) of forty-seven hips, but none of the lesions compromised the stability of the prosthesis or the bone and there were no associated fractures. At an average of ten years postoperatively, the Tri-Lock femoral component functioned well overall and patient satisfaction was high.

Bone density and functional results after femoral revision with a cementless press-fit stem.

PubMed

Canovas, F; Roche, O; Girard, J; Bonnomet, F; Goldschild, M; Le Béguec, P

2015-05-01

The influence of radiographic bone density changes in the area surrounding a total hip arthroplasty (THA) revision with a cementless press-fit stem is unknown, notably in terms of functional results. We have therefore conducted a study aiming to (1) propose a radiographic method to assess bone density, (2) measure the functional effects of reduced bone density, and (3) determine the factors contributing to these modifications. A reduction in radiographic bone density has a negative influence on the functional result after revision using a cementless press-fit stem. We retrospectively assessed 150 THA revisions at a mean follow-up of 6.3 ± 3.2 years (range, 2-15 years). The clinical assessment was based on the Harris Hip Score. Bone density modifications were measured radiographically and the method was evaluated. The change in bone density was classified into two groups: (1) bone density not reduced or < 2 Gruen zones (118 cases [79%]); (2) bone density reduced ≥ 2 zones (32 cases [21%]). The variables showing a potential influence were the Cortical Index (CI), the type of primary stability with the press-fit system, and the femoral implant length. Inter- and intraobserver reliability of radiographic bone density measurement was evaluated as moderate or good (Kappa, 0.58; 0.60 and 0.67, respectively). For the Harris Hip Score at follow-up, there was a borderline statistical relation between stages 1 and 2: for the 118 stage 1 patients, this score was 83.62 ± 11.54 (range, 27-99) versus 78.34 ± 15.98 (range, 62-91) for stage 2 patients (P = 0.09). A CI ≤ 0.44 showed mediocre bone quality contributing to decreased bone density (P < 0.02). On the other hand, there was no statistically significant relation with the type of primary fixation (P = 0.34) or the length of the implant (P = 0.23). A cementless revision femoral stem can induce a reduction in bone density with possible functional effects. The negative role played by bone scarcity on the functional score is confirmed, and even though the difference is not statistically significant, we suggest using a short stem when this is possible. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Bone turnover and periprosthetic bone loss after cementless total hip arthroplasty can be restored by zoledronic acid: a prospective, randomized, open-label, controlled trial.

PubMed

Huang, Tsan-Wen; Wang, Chao-Jan; Shih, Hsin-Nung; Chang, Yuhan; Huang, Kuo-Chin; Peng, Kuo-Ti; Lee, Mel S

2017-05-22

Although the loss of bone mineral density (BMD) after total hip arthroplasty (THA) is a known problem, it remains unresolved. This study prospectively examined the effect of zoledronic acid (ZA) on bone turnover and BMD after cementless THA. Between January 2010 and August 2011, 60 patients who underwent cementless THA were randomly assigned to receive either ZA infusion or placebo (0.9% normal saline only) postoperatively. ZA was administered at 2 day and 1 year postoperatively. Periprosthetic BMD in seven Gruen zones was assessed preoperatively and at given time points for 2 years. Serum markers of bone turnover, functional scales, and adverse events were recorded. Each group contained 27 patients for the final analysis. The loss of BMD across all Gruen zones (significantly in zones 1 and 7) up to 2 years postoperatively was noted in the placebo group. BMD was significantly higher in the ZA group than in the placebo group in Gruen zones 1, 2, 6, and 7 at 1 year and in Gruen zones 1, 6, and 7 at 2 years (p < 0.05). Compared with baseline measures of BMD, the ZA group had increased BMD in zones 1, 2, 4, 5, 6, and 7 at 1 year and in zones 1, 4, 6, and 7 at 2 years (p < 0.05). Serum bone-specific alkaline phosphatase and N-telopeptide of procollagen I levels were significantly increased at 6 weeks in the placebo group and decreased after 3 months in the ZA group. A transient decrease in osteocalcin level was found at 6 months in the ZA group. Functional scales and adverse events were not different between the two groups. The loss of periprosthetic BMD, especially in the proximal femur (zones 1 and 7), after cementless THA could be effectively reverted using ZA. In addition, bone turnover markers were suppressed until 2 years postoperatively following ZA administration. Chang Gung Memorial Hospital Protocol Record 98-1150A3, Prevention of Periprosthetic Bone Loss After Total Hip Replacement by Annual Bisphosphonate Therapy, has been reviewed and will be made public on ClinicalTrials.gov. NCT02838121 . Registered on 19 July, 2016.

Does using a polyethylene RM press-fit cup modify the preparation of the acetabulum and acetabular offset in primary hip arthroplasty?

PubMed

Erivan, R; Aubret, S; Villatte, G; Mulliez, A; Descamps, S; Boisgard, S

2017-09-01

When performing total hip arthroplasty (THA), it is important to maintain the femoral and acetabular offsets to ensure good joint stability and to restore the function of the hip abductor muscles. In our practice, we mainly use a lateralized stem and hollow out the acetabulum to the quadrilateral plate to accommodate a press-fit polyethylene cup. However, the repercussions of this preparation method, which is driven by the cup's design, are not known. We carried out a retrospective study to assess: (1) the changes in the femoral and acetabular offset; (2) the height of the center of rotation; and (3) the repercussions on wear. We hypothesized there would be no significant differences between the preoperative and postoperative femoral and acetabular offsets. We reviewed 88 primary THA cases performed with the RM Pressfit™ cup that had a minimum of 5 years' follow-up. A lateralized self-locking Muller-type cemented femoral stem was used in 92.0% of cases and a standard stem in 8.0%. Measurements were done on plain radiographs with MHP™ and Mesurim Pro™ software. The average follow-up was 6.5 years (5-8). On average, the acetabular offset was reduced by 2.75mm±5.9 mm (range: -17.5 to +10.6 mm) (P<0.001) and the femoral offset was increased by 0.01mm±5.5 mm (range: -17.8 to +11.0 mm) (P=0.99). In terms of total offset, medialization of 2.74mm±7 mm (range: -17.7 to +18.2mm) was found (P=0.001). The acetabular center of rotation was on average 4.77mm±5.1 mm higher (P<0.001). The mean annual wear at the more recent follow-up (min.: 5 years) was 0.068mm (range: 0.01 to 0.25mm) per year. The wear was not impacted by having more than 5mm change in offset. Measurements of acetabular offset revealed statistically significant medialization due to the type of implant used and the surgical technique. The anatomical technique consists of positioning the cup in subchondral bone without contacting the quadrilateral plate. This preserves bone stock, which may be useful later on if the cup is revised, particularly in younger patients. Conversely, the femoral offset did not change significantly, despite the use of lateralized stems in 92.0% of cases. We measured an annual wear rate of 0.068mm per year, which is lower than in other published studies, possibly because our patient population was older. IV, retrospective study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Effects of Titanium Mesh Surfaces-Coated with Hydroxyapatite/β-Tricalcium Phosphate Nanotubes on Acetabular Bone Defects in Rabbits

PubMed Central

Nguyen, Thuy-Duong Thi; Bae, Tae-Sung; Yang, Dae-hyeok; Park, Myung-sik; Yoon, Sun-jung

2017-01-01

The management of severe acetabular bone defects in revision reconstructive orthopedic surgery is challenging. In this study, cyclic precalcification (CP) treatment was used on both nanotube-surface Ti-mesh and a bone graft substitute for the acetabular defect model, and its effects were assessed in vitro and in vivo. Nanotube-Ti mesh coated with hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) was manufactured by an anodizing and a sintering method, respectively. An 8 mm diameter defect was created on each acetabulum of eight rabbits, then treated by grafting materials and covered by Ti meshes. At four and eight weeks, postoperatively, biopsies were performed for histomorphometric analyses. The newly-formed bone layers under cyclic precalcified anodized Ti (CP-AT) meshes were superior with regard to the mineralized area at both four and eight weeks, as compared with that under untreated Ti meshes. Active bone regeneration at 2–4 weeks was stronger than at 6–8 weeks, particularly with treated biphasic ceramic (p < 0.05). CP improved the bioactivity of Ti meshes and biphasic grafting materials. Moreover, the precalcified nanotubular Ti meshes could enhance early contact bone formation on the mesh and, therefore, may reduce the collapse of Ti meshes into the defect, increasing the sufficiency of acetabular reconstruction. Finally, cyclic precalcification did not affect bone regeneration by biphasic grafting materials in vivo. PMID:28686210

Atypical anterior wall fracture of the acetabulum: case series of anterior acetabular rim fracture without involvement of the pelvic brim.

PubMed

Lenarz, Christopher J; Moed, Berton R

2007-09-01

The purpose of this study was to describe a form of anterior wall acetabular fracture, which has been inadequately defined in the literature. Retrospective analysis of consecutive patients. Level 1 trauma center. A retrospective analysis of consecutive acetabulum patients treated by a single surgeon between 1999 and 2005 identified 6 patients with a form of anterior wall fracture without involvement of the pelvic brim. All fractures were treated operatively. Open reduction and internal fixation through an anterior surgical approach. Final radiographic appearance and modified Merle d'Aubigne score. All 6 cases demonstrated characteristics of an atypical fracture of the anterior wall, involving the anterior rim of the acetabulum similar in nature to those described for the posterior wall, rather than the standard anterior wall fracture type described by Letournel. Of the 6 cases that were identified, 5 had follow-up 1 year or greater with a mean modified Merle d'Aubigne Score of 17 (range: 17-18). A form of anterior wall acetabular fracture exists, which involves the anterior acetabular rim without involvement of the pelvic brim. It can occur in young patients with high-energy mechanisms of injury, as well as in the elderly with low-energy trauma. With appropriate surgical management, using a modified Smith-Peterson approach, good to excellent clinical outcomes should be expected.

High incidence of intraoperative calcar fractures with the cementless CLS Spotorno stem.

PubMed

Timmer, Carla; Gerhardt, Davey M J M; de Visser, Enrico; de Kleuver, Marinus; van Susante, Job L C

2018-05-07

This study reports on the incidence of intraoperative calcar fractures with the cementless Spotorno (CLS) stem, and the potential role of a learning curve and implant positioning is investigated. After introduction of the CLS stem, 800 consecutive cementless total hip arthroplasties (THA) were analyzed. The incidence of calcar fracture in the first 400 THA was compared with the second 400 THA, in order to study a potential learning curve effect. According to the instruction for users, varus positioning of the stem was avoided and a femoral neck osteotomy was aimed relatively close to the lesser trochanter since these are assumed to be correlated with calcar fractures. Implant positioning (neck-shaft angle, femoral offset and osteotomy-lesser trochanter distance) was measured on postoperative pelvic radiographs of all THA with calcar fractures and 100 randomly selected uncomplicated control cases. Seventeen (2.1%) intraoperative calcar fractures were recorded. The incidence of calcar fracture differed between the first 400 THA (n = 11) and the second 400 THA (n = 6). This difference was not statistically significant (p = 0.220); however, these numbers indicate a trend toward a learning effect. No significant difference in stem positioning nor the height of the femoral neck osteotomy was measured between THA with a calcar fracture (n = 17) and the control cases (n = 100). We report on a high incidence of intraoperative calcar fractures with the use of a CLS stem. The risk for calcar fractures remains clinically significant even after adequate implant positioning in the hands of experienced hip surgeons. Surgeons should be aware of this implant related phenomenon and be alert on this phenomenon intraoperatively.

Full-field measurement of micromotion around a cementless femoral stem using micro-CT imaging and radiopaque markers.

PubMed

Malfroy Camine, V; Rüdiger, H A; Pioletti, D P; Terrier, A

2016-12-08

A good primary stability of cementless femoral stems is essential for the long-term success of total hip arthroplasty. Experimental measurement of implant micromotion with linear variable differential transformers is commonly used to assess implant primary stability in pre-clinical testing. But these measurements are often limited to a few distinct points at the interface. New techniques based on micro-computed tomography (micro-CT) have recently been introduced, such as Digital Volume Correlation (DVC) or markers-based approaches. DVC is however limited to measurement around non-metallic implants due to metal-induced imaging artifacts, and markers-based techniques are confined to a small portion of the implant. In this paper, we present a technique based on micro-CT imaging and radiopaque markers to provide the first full-field micromotion measurement at the entire bone-implant interface of a cementless femoral stem implanted in a cadaveric femur. Micromotion was measured during compression and torsion. Over 300 simultaneous measurement points were obtained. Micromotion amplitude ranged from 0 to 24µm in compression and from 0 to 49µm in torsion. Peak micromotion was distal in compression and proximal in torsion. The technique bias was 5.1µm and its repeatability standard deviation was 4µm. The method was thus highly reliable and compared well with results obtained with linear variable differential transformers (LVDTs) reported in the literature. These results indicate that this micro-CT based technique is perfectly relevant to observe local variations in primary stability around metallic implants. Possible applications include pre-clinical testing of implants and validation of patient-specific models for pre-operative planning. Copyright © 2016 Elsevier Ltd. All rights reserved.

Statistical analysis of interfacial gap in a cementless stem FE model.

PubMed

Park, Youngbae; Choi, Donok; Hwang, Deuk Soo; Yoon, Yong-San

2009-02-01

In cementless total hip arthroplasty, a fair amount of interfacial gap exists between the femoral stem and the bone. However, the effect of these gaps on the mechanical stability of the stem is poorly understood. In this paper, a finite element model with various interfacial gap definitions is used to quantify the effect of interfacial gaps on the primary stability of a Versys Fiber Metal Taper stem under stair climbing loads. In the first part, 500 random interfacial gap definitions were simulated. The resulting micromotion was approximately inversely proportional to the contact ratio, and the variance of the micromotion was greater with a lower contact ratio. Moreover, when the magnitude of the micromotion was compared between the gap definitions that had contact at a specific site and those that had no contact at that site, it was found that gaps located in the proximal-medial region of the stem surface had the most important effect on the micromotion. In a second trial, 17 gap definitions mimicking a gap pattern that has been observed experimentally were simulated. For a given contact ratio, the micromotion observed in the second trial was lower than the average result of those in the first, where the gaps were placed randomly. In either trial, when the contact ratio was higher than 40%, the micromotion showed no significant difference (first trial) or a gentle slope (-0.24 mum% in the second trial) in relation to the contact ratio. Considering the reported contact ratios for properly implanted stems, variations in the amount of interfacial gap would not likely cause a drastic difference in micromotion, and this effect could be easily overshadowed by other clinical factors. In conclusion, differences in interfacial gaps are not expected to have a noticeable effect on the clinical micromotion of this cementless stem.

The cementless Bicontact stem in a prospective dual-energy X-ray absorptiometry study.

PubMed

Lerch, Matthias; Kurtz, Agnes; Windhagen, Henning; Bouguecha, Anas; Behrens, Bernd A; Wefstaedt, Patrick; Stukenborg-Colsman, Christina M

2012-11-01

The cementless Bicontact total hip arthroplasty (THA) system (AESCULAP AG, Tuttlingen, Germany) was introduced in 1986/1987 and has been in successful clinical use in an unaltered form up to today. Although good long-term results with the Bicontact stem have been published, it is questionable whether the implant provides the criteria for a state-of-the-art stem regarding proximal bone stock preservation. The purpose of the study was to monitor the periprosthetic bone mineral density (BMD) in a prospective two-year follow-up dual-energy X-ray absorptiometry (DEXA) study. After power analysis, a consecutive series of 25 patients with unilateral Bicontact stem implantation was examined clinically and underwent DEXA examinations. Scans of seven regions of interest were taken preoperatively and at one week, six months, and one and two years. One patient required stem revision due to a deep infection. The Harris Hip Score increased significantly by 44 points. The most significant bone loss was observed in the calcar region (R7) in the first six months (-19.2 %). It recovered in the following 18 months to -8.5 %. The BMD in the greater trochanter dropped significantly after six months and remained stable at this level. BMD exceeded baseline values in distal regions and even more in the lesser trochanter region after two years. We conclude that the Bicontact stem provides adequate proximal bone stock preservation. We observed some signs of stress shielding at the tip of the stem, which is inevitable to some degree in THA with cementless straight stems. However, in this prospective DEXA investigation, we showed that proximal off-loading does not occur after THA with the Bicontact system. Thus, we believe that this stem is still a state-of-the-art implant.

A Prolonged Time Interval Between Trauma and Prophylactic Radiation Therapy Significantly Increases the Risk of Heterotopic Ossification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mourad, Waleed F., E-mail: Waleed246@gmail.com; Department of Radiation Oncology, Beth Israel Medical Center, New York, NY; Packianathan, Satyaseelan

2012-03-01

Purpose: To ascertain whether the time from injury to prophylactic radiation therapy (RT) influences the rate of heterotopic ossification (HO) after operative treatment of displaced acetabular fractures. Methods and Materials: This is a single-institution, retrospective analysis of patients referred for RT for the prevention of HO. Between January 2000 and January 2009, 585 patients with displaced acetabular fractures were treated surgically followed by RT for HO prevention. We analyzed the effect of time from injury on prevention of HO by RT. In all patients, 700 cGy was prescribed in a single fraction and delivered within 72 hours postsurgery. The patientsmore » were stratified into five groups according to time interval (in days) from the date of their accident to the date of RT: Groups A {<=}3, B {<=}7, C {<=}14, D {<=}21, and E >21days. Results: Of the 585 patients with displaced acetabular fractures treated with RT, (18%) 106 patients developed HO within the irradiated field. The risk of HO after RT increased from 10% for RT delivered {<=}3 days to 92% for treatment delivered >21 days after the initial injury. Wilcoxon test showed a significant correlation between the risk of HO and the length of time from injury to RT (p < 0.0001). Chi-square test and multiple logistic regression analysis showed no significant association between all other factors and the risk of HO (race, gender, cause and type of fracture, surgical approach, or the use of indomethacin). Conclusions: Our data suggest that there is higher incidence and risk of HO if prophylactic RT is significantly delayed after a displaced acetabular fracture. Thus, RT should be administered as early as clinically possible after the trauma. Patients undergoing RT >3 weeks from their displaced acetabular fracture should be informed of the higher risk (>90%) of developing HO despite prophylaxis.« less

Does semi-automatic bone-fragment segmentation improve the reproducibility of the Letournel acetabular fracture classification?

PubMed

Boudissa, M; Orfeuvre, B; Chabanas, M; Tonetti, J

2017-09-01

The Letournel classification of acetabular fracture shows poor reproducibility in inexperienced observers, despite the introduction of 3D imaging. We therefore developed a method of semi-automatic segmentation based on CT data. The present prospective study aimed to assess: (1) whether semi-automatic bone-fragment segmentation increased the rate of correct classification; (2) if so, in which fracture types; and (3) feasibility using the open-source itksnap 3.0 software package without incurring extra cost for users. Semi-automatic segmentation of acetabular fractures significantly increases the rate of correct classification by orthopedic surgery residents. Twelve orthopedic surgery residents classified 23 acetabular fractures. Six used conventional 3D reconstructions provided by the center's radiology department (conventional group) and 6 others used reconstructions obtained by semi-automatic segmentation using the open-source itksnap 3.0 software package (segmentation group). Bone fragments were identified by specific colors. Correct classification rates were compared between groups on Chi 2 test. Assessment was repeated 2 weeks later, to determine intra-observer reproducibility. Correct classification rates were significantly higher in the "segmentation" group: 114/138 (83%) versus 71/138 (52%); P<0.0001. The difference was greater for simple (36/36 (100%) versus 17/36 (47%); P<0.0001) than complex fractures (79/102 (77%) versus 54/102 (53%); P=0.0004). Mean segmentation time per fracture was 27±3min [range, 21-35min]. The segmentation group showed excellent intra-observer correlation coefficients, overall (ICC=0.88), and for simple (ICC=0.92) and complex fractures (ICC=0.84). Semi-automatic segmentation, identifying the various bone fragments, was effective in increasing the rate of correct acetabular fracture classification on the Letournel system by orthopedic surgery residents. It may be considered for routine use in education and training. III: prospective case-control study of a diagnostic procedure. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Evaluation of patients with painful total hip arthroplasty using combined single photon emission tomography and conventional computerized tomography (SPECT/CT) - a comparison of semi-quantitative versus 3D volumetric quantitative measurements.

PubMed

Barthassat, Emilienne; Afifi, Faik; Konala, Praveen; Rasch, Helmut; Hirschmann, Michael T

2017-05-08

It was the primary purpose of our study to evaluate the inter- and intra-observer reliability of a standardized SPECT/CT algorithm for evaluating patients with painful primary total hip arthroplasty (THA). The secondary purpose was a comparison of semi-quantitative and 3D volumetric quantification method for assessment of bone tracer uptake (BTU) in those patients. A novel SPECT/CT localization scheme consisting of 14 femoral and 4 acetabular regions on standardized axial and coronal slices was introduced and evaluated in terms of inter- and intra-observer reliability in 37 consecutive patients with hip pain after THA. BTU for each anatomical region was assessed semi-quantitatively using a color-coded Likert type scale (0-10) and volumetrically quantified using a validated software. Two observers interpreted the SPECT/CT findings in all patients two times with six weeks interval between interpretations in random order. Semi-quantitative and quantitative measurements were compared in terms of reliability. In addition, the values were correlated using Pearson`s correlation. A factorial cluster analysis of BTU was performed to identify clinically relevant regions, which should be grouped and analysed together. The localization scheme showed high inter- and intra-observer reliabilities for all femoral and acetabular regions independent of the measurement method used (semiquantitative versus 3D volumetric quantitative measurements). A high to moderate correlation between both measurement methods was shown for the distal femur, the proximal femur and the acetabular cup. The factorial cluster analysis showed that the anatomical regions might be summarized into three distinct anatomical regions. These were the proximal femur, the distal femur and the acetabular cup region. The SPECT/CT algorithm for assessment of patients with pain after THA is highly reliable independent from the measurement method used. Three clinically relevant anatomical regions (proximal femoral, distal femoral, acetabular) were identified.

Pelvic Incidence and Acetabular Version in Slipped Capital Femoral Epiphysis.

PubMed

Gebhart, Jeremy J; Bohl, Michael S; Weinberg, Douglas S; Cooperman, Daniel R; Liu, Raymond W

2015-09-01

The etiology of slipped capital femoral epiphysis (SCFE) is multifactorial, but the role of sagittal balance of the pelvis as a contributing factor to its development has not been well studied. Our primary purpose was to determine whether a smaller pelvic incidence (PI), a position-independent anatomic parameter that regulates pelvic orientation, could be a factor that increases shear stress in the epiphyseal growth plate and potentially contributes to the development of SCFE. We also set out to determine whether acetabular retroversion was associated with SCFE. We obtained 14 cadaveric pelvi from the Hamann-Todd Osteological Collection whose femurs showed evidence of post-SCFE deformity. Two hundred age-matched, sex-matched, and race-matched pelvi were used as controls. PI and acetabular version were measured using standardized lateral photographs and goniometers, respectively. T tests were performed to evaluate for differences in measured parameters between groups. The mean PI was 40.6±6.1 degrees for SCFE specimens and 47.4±9.9 degrees for normal specimens (P=0.01). The mean version of SCFE and normal acetabula was 15±7 and 17±6 degrees, respectively (P=0.39). There was also no significant difference in version between SCFE acetabula and the contralateral, uninvolved acetabular of the same specimen (15±7 vs. 17±8 degrees, P=0.33). Specimens with SCFE deformity demonstrated a smaller PI than a large cohort of normal control specimens. We found no significant difference between acetabular version of specimens with and without SCFE deformity. Contralateral or unaffected acetabuli of SCFE specimens were not more retroverted than the affected side of the same specimen. Sagittal balance of the pelvis, and particularly decreased PI, may play an important role in the development of SCFE. The influence of mechanical factors beyond the hip joint in the development of SCFE should be considered by clinicians.

Cemented tibial component fixation performs better than cementless fixation: a randomized radiostereometric study comparing porous-coated, hydroxyapatite-coated and cemented tibial components over 5 years.

PubMed

Carlsson, Ake; Björkman, Anders; Besjakov, Jack; Onsten, Ingemar

2005-06-01

The question whether the tibial component of a total knee arthroplasty should be fixed to bone with or without bone cement has not yet been definitely answered. We studied movements between the tibial component and bone by radiostereometry (RSA) in total knee replacement (TKR) for 3 different types of fixation: cemented fixation (C-F), uncemented porous fixation (UC-F) and uncemented porous hydroxyapatite fixation (UCHA-F). 116 patients with osteoarthrosis, who had 146 TKRs, were included in 2 randomized series. The first series included 86 unilateral TKRs stratified into 1 of the 3 types of fixation. The second series included 30 patients who had simultaneous bilateral TKR surgery, and who were stratified into 3 subgroups of pairwise comparisons of the 3 types of fixation. After 5 years 2 knees had been revised, neither of which were due to loosening. 1 UCHA-F knee in the unilateral series showed a large and continuous migration and a poor clinical result, and is a pending failure. The C-F knees rotated and migrated less than UC-F and UCHA-F knees over 5 years. UCHA-F migrated less than UC-F after 1 year. Cementing of the tibial component offers more stable bone-implant contact for 5 years compared to uncemented fixation. When using uncemented components, however, there is evidence that augmenting a porous surface with hydroxyapatite may mean less motion between implant and bone after the initial postoperative year.

Correlation of Cup Inclination Angle with Liner Wear for Metal-on-polyethylene in Hip Primary Arthroplasty.

PubMed

Tian, Jia-Liang; Sun, Li; Hu, Rui-Yin; Han, Wei; Tian, Xiao-Bin

2017-05-01

The relationship between cup inclination angle and liner wear is controversial. Most authors in the published literature agree that the ideal cup inclination is associated with lower inner wear; however, some disagree. All previous studies did not control for femoral head diameter and inclination, so it is difficult to assess the relative or synergistic effects of cup angle on outcomes. We retrospectively reviewed 154 patients (171 hips) with primary total hip arthroplasties performed from 2001 to 2004. All surgeries had been performed by the same physician team. A posterior approach was applied in all patients. All prostheses were non-cemented cups with a 28-mm metal head. Inclusion criteria included that the radiographic material was not completed or lost for primary or last follow up. Patients were divided into four groups according to different cup inclination angle. There were 108 hips with inclination angles below 50°; 35 hips with angles between 50° and 55°; 17 hips with angles between 55° and 60°; and 11 hips with angles greater than 60°. An immediate postoperative radiograph was compared with a follow-up radiograph. Clinical and radiographic data were collected on standardized hip evaluation forms preoperatively, 6 months after surgery and at yearly follow-up visits. Radiographs were digitized and enlarged 100%. After the radiographs were digitized, polyethylene wear rates and acetabular cup abduction were measured on all patients with Cavas 15.0 software. The results were analyzed using Student's two-tailed paired t-test with SPSS 11.5. The preoperative mean Harris hip score improved from 45.36 to 93.5 points 10 years after surgery. No acetabular component was revised for aseptic loosening. Three patients (three hips) had to undergo bone grafting and a lined arthroplasty for severe osteolysis around the acetabular component. The rate of implant survival at 10 years with respect to loosening was 100%. The mean liner wear rate was 0.135 mm/year in cups with inclination angles below 50°, 0.144 mm/year between 50° and 55°, 0.260 mm/year between 55° and 60°, and 0.403 mm/year when the angle was greater than 60°. Liner wear increased when the cup angle was larger than 55° (P < 0.05). For metal-on-polyethylene prostheses, liner wear correlates with cup inclination angle larger than 55°. The ideal abduction angle for metal-on-polyethylene prostheses is less than 55°. © 2017 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

Fluoroscopy and imageless navigation enable an equivalent reconstruction of leg length and global and femoral offset in THA.

PubMed

Weber, Markus; Woerner, Michael; Springorum, Robert; Sendtner, Ernst; Hapfelmeier, Alexander; Grifka, Joachim; Renkawitz, Tobias

2014-10-01

Restoration of biomechanics is a major goal in THA. Imageless navigation enables intraoperative control of leg length equalization and offset reconstruction. However, the effect of navigation compared with intraoperative fluoroscopy is unclear. We asked whether intraoperative use of imageless navigation (1) improves the relative accuracy of leg length and global and femoral offset restoration; (2) increases the absolute precision of leg length and global and femoral offset equalization; and (3) reduces outliers in a reconstruction zone of ± 5 mm for leg length and global and femoral offset restoration compared with intraoperative fluoroscopy during minimally invasive (MIS) THA with the patient in a lateral decubitus position. In this prospective study a consecutive series of 125 patients were randomized to either navigation-guided or fluoroscopy-controlled THA using sealed, opaque envelopes. All patients received the same cementless prosthetic components through an anterolateral MIS approach while they were in a lateral decubitus position. Leg length, global or total offset (representing the combination of femoral and acetabular offset), and femoral offset differences were restored using either navigation or fluoroscopy. Postoperatively, residual leg length and global and femoral offset discrepancies were analyzed on magnification-corrected radiographs of the pelvis by an independent and blinded examiner using digital planning software. Accuracy was defined as the relative postoperative difference between the surgically treated and the unaffected contralateral side for leg length and offset, respectively; precision was defined as the absolute postoperative deviation of leg length and global and femoral offset regardless of lengthening or shortening of leg length and offset throughout the THA. All analyses were performed per intention-to-treat. Analyzing the relative accuracy of leg length restoration we found a mean difference of 0.2 mm (95% CI, -1.0 to +1.4 mm; p = 0.729) between fluoroscopy and navigation, 0.2 mm (95 % CI, -0.9 to +1.3 mm; p = 0.740) for global offset and 1.7 mm (95 % CI, +0.4 to +2.9 mm; p = 0.008) for femoral offset. For the absolute precision of leg length and global and femoral offset equalization, there was a mean difference of 1.7 ± 0.3 mm (p < 0.001) between fluoroscopy and navigation. The biomechanical reconstruction with a residual leg length and global and femoral offset discrepancy less than 5 mm and less than 8 mm, respectively, succeeded in 93% and 98%, respectively, in the navigation group and in 54% and 95%, respectively, in the fluoroscopy group. Intraoperative fluoroscopy and imageless navigation seem equivalent in accuracy and precision to reconstruct leg length and global and femoral offset during MIS THA with the patient in the lateral decubitus position.

Fabrication and wear test of a continuous fiber/particulate composite total surface hip replacement

NASA Technical Reports Server (NTRS)

Roberts, J. C.; Ling, F. F.; Jones, W. R., Jr.

1981-01-01

Continuous fiber woven E-glass composite femoral shells having the ame elastic properties as bone were fabricated. The shells were then encrusted with filled epoxy wear resistant coatings and run dry against ultrahigh molecular weight polyethylene acetabular cups in 42,000 and 250,000 cycle were tests on a total hip simulator. The tribological characteristics of these shells atriculating with the acetabular cups are comparable to a vitallium bal articulating with an ultrahigh molecular weight polyethylene cup.

Primary Stability Recognition of the Newly Designed Cementless Femoral Stem Using Digital Signal Processing

PubMed Central

Salleh, Sh-Hussain; Hamedi, Mahyar; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Mohd Noor, Alias; Harris, Arief Ruhullah A.; Abdul Majid, Norazman

2014-01-01

Stress shielding and micromotion are two major issues which determine the success of newly designed cementless femoral stems. The correlation of experimental validation with finite element analysis (FEA) is commonly used to evaluate the stress distribution and fixation stability of the stem within the femoral canal. This paper focused on the applications of feature extraction and pattern recognition using support vector machine (SVM) to determine the primary stability of the implant. We measured strain with triaxial rosette at the metaphyseal region and micromotion with linear variable direct transducer proximally and distally using composite femora. The root mean squares technique is used to feed the classifier which provides maximum likelihood estimation of amplitude, and radial basis function is used as the kernel parameter which mapped the datasets into separable hyperplanes. The results showed 100% pattern recognition accuracy using SVM for both strain and micromotion. This indicates that DSP could be applied in determining the femoral stem primary stability with high pattern recognition accuracy in biomechanical testing. PMID:24800230

Optimization of custom cementless stem using finite element analysis and elastic modulus distribution for reducing stress-shielding effect.

PubMed

Saravana Kumar, Gurunathan; George, Subin Philip

2017-02-01

This work proposes a methodology involving stiffness optimization for subject-specific cementless hip implant design based on finite element analysis for reducing stress-shielding effect. To assess the change in the stress-strain state of the femur and the resulting stress-shielding effect due to insertion of the implant, a finite element analysis of the resected femur with implant assembly is carried out for a clinically relevant loading condition. Selecting the von Mises stress as the criterion for discriminating regions for elastic modulus difference, a stiffness minimization method was employed by varying the elastic modulus distribution in custom implant stem. The stiffness minimization problem is formulated as material distribution problem without explicitly penalizing partial volume elements. This formulation enables designs that could be fabricated using additive manufacturing to make porous implant with varying levels of porosity. Stress-shielding effect, measured as difference between the von Mises stress in the intact and implanted femur, decreased as the elastic modulus distribution is optimized.

Primary stability recognition of the newly designed cementless femoral stem using digital signal processing.

PubMed

Baharuddin, Mohd Yusof; Salleh, Sh-Hussain; Hamedi, Mahyar; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Mohd Noor, Alias; Harris, Arief Ruhullah A; Abdul Majid, Norazman

2014-01-01

Stress shielding and micromotion are two major issues which determine the success of newly designed cementless femoral stems. The correlation of experimental validation with finite element analysis (FEA) is commonly used to evaluate the stress distribution and fixation stability of the stem within the femoral canal. This paper focused on the applications of feature extraction and pattern recognition using support vector machine (SVM) to determine the primary stability of the implant. We measured strain with triaxial rosette at the metaphyseal region and micromotion with linear variable direct transducer proximally and distally using composite femora. The root mean squares technique is used to feed the classifier which provides maximum likelihood estimation of amplitude, and radial basis function is used as the kernel parameter which mapped the datasets into separable hyperplanes. The results showed 100% pattern recognition accuracy using SVM for both strain and micromotion. This indicates that DSP could be applied in determining the femoral stem primary stability with high pattern recognition accuracy in biomechanical testing.

[Dislocated fracture of the lesser trochanter with malrotation of the stem after robot assisted implantation of a cementless hip prosthesis: a casuistic report].

PubMed

Prymka, M; Hassenpflug, J

2003-08-01

This paper presents the case of a 63 year old female with a severe coxarthrosis. She got a robot assited implantation of a cementless hip prosthesis (Osteolock, Stryker-Howmedica, Mühlheim). As operation robot the CASPAR-System (Orto-Maquet, Rastatt) was used. Initially, the clinical progress of the patient was fine. She was nearly painfree within 14 days and showed an acceptable range of motion in the operated joint (flexion/ extension 90 degrees /05 degrees /00 degrees ). She was mobilized with crutches and 15 kg weight bearing at the operated leg. 3 weeks postoperative the patient complaint about increasing pain without trauma or intensification of the weight bearing. X-rays showed not only a dislocated fracture of the lesser trochanter, but also a sinking combined with a malrotation of the stem. A revision operation was necessary,where we implanted a cemented stem. Now clinical progress was completely satisfying.

Controversies in Treatment of Acetabular Fracture

PubMed Central

Grubor, Predrag; Krupic, Ferid; Biscevic, Mirza; Grubor, Milan

2015-01-01

Introduction: Acetabular fractures treatment represents a great controversy, challenge and dilemma for an orthopedic surgeon. Aim: The aim of the paper was to present the results of treatment of 96 acetabular fractures in the Clinic of Traumatology Banja Luka, in the period from 2003 to 2013, as well as to raise awareness regarding the controversy in the methods of choice in treating acetabulum fractures. Material and methods: The series consists of 96 patients, 82 males and 14 females, average age 40.5 years. Traffic trauma was the cause of fractures in 79 patients (85%), and in 17 patients (15%) fractures occurred due to falls from height. Polytrauma was present in 31 patients (32%). According to the classification of Judet and Letournel, representation of acetabular fractures was as follows: posterior wall in 32 patients, posterior column in 28, anterior wall in 4, anterior column in 2, transverse fractures in 8, posterior wall and posterior column in 10, anterior and posterior wall in 6, both- column in 4 and transversal fracture and posterior wall in 2 patients. 14 patients were treated with traction, that is, 6 patients with femoral traction and 8 patients with both lateral and femoral traction. 82 patients (86.4%) were surgically treated. Kocher-Langenbeck approach was applied in the treatment of 78 patients. In two patients from the Kocher-Langenbeck’s approach, the Ollier’s approach had to be applied as well. Two acetabular were primarily treated with Ollier’s approach. Extended Smith- Peterson’s approach was applied 4 times, and Emile Letournel’s (ilioinguinal) approach 14 times. Results: Functional outcome (after follow-up of 18 months), according to the Harris hip score of surgical treatment in 82 patients, was as follows: good 46 (56%), satisfactory 32 (39%) and poor 4 (5%). Results of acetabulum fractures treated with traction were: good 8 (57%), satisfactory 4 (28%) and poor 2 (15%). According to the Brook’s classification of heterotopic ossification, periarticular hetero-tropic calcifications after surgical treatment were: 0° in 65 patients (79%), I-II° in 9 patients (11%) and III-IV ° in 8 patients (10%). Calcifications in 14 patients treated with traction of heterotopic ossification by Brook-s classification were as follows: 0° in 10 patients (72%), I-II ° in 3 patients (22%) and III-IV° in 1 patient (6%). Conclusion: At the occurrence of acetabular fracture, it is necessary to start the treatment immediately, with an obligatory application of thromboembolic and antibiotic prophylaxis. Conservative treatment is acceptable if the dislocation of fracture is less than 5 mm. Indications for surgical treatment are incongruent or unstable fractures with verified dislocation greater than 5 mm, as well as when the radiography measured by JM Matta shows incongruence of acetabular roof less than 40° in all planes. Kocher-Langenbeck approach is the choice of surgical approach for the management of posterior column / wall, and Letournel’s (ilioinguinal) approach is the choice for the management of anterior wall/column. PMID:25870470

Early polyethylene wear and osteolysis with ABG acetabular cups (7- to 12-year follow-up).

PubMed

Badhe, Sachin; Livesley, Peter

2006-02-01

We reviewed 81 consecutive ABG I primary total hip replacements implanted in 72 patients between January 1993 and December 1998. The mean follow-up was 8.2 (range 7-12) years. There was significant polyethylene wear and osteolysis associated with the acetabular cup . The cumulative survival of the cup with revision being the end point at 8.2 years was 95.1% (95% CI: 92-97.6%). However, the cumulative survival of the cup with revision and aseptic loosening together was 72% (95% CI: 61-78%) and survival of the acetabular liner for wear was 62% (95% CI: 48-74%). Stem survival with revision being the end point was 100%. In spite of significant radiological failures of the cups, most patients remained asymptomatic. Though results of the ABG stems in this series were good, we advocate a regular follow-up of all these hips in view of the poor outcome of the cups.

Early polyethylene wear and osteolysis with ABG acetabular cups (7- to 12-year follow-up)

PubMed Central

Livesley, Peter

2005-01-01

We reviewed 81 consecutive ABG I primary total hip replacements implanted in 72 patients between January 1993 and December 1998. The mean follow-up was 8.2 (range 7–12) years. There was significant polyethylene wear and osteolysis associated with the acetabular cup .The cumulative survival of the cup with revision being the end point at 8.2 years was 95.1% (95% CI: 92–97.6%). However, the cumulative survival of the cup with revision and aseptic loosening together was 72% (95% CI: 61–78%) and survival of the acetabular liner for wear was 62% (95% CI: 48–74%). Stem survival with revision being the end point was 100%. In spite of significant radiological failures of the cups, most patients remained asymptomatic. Though results of the ABG stems in this series were good, we advocate a regular follow-up of all these hips in view of the poor outcome of the cups. PMID:16283307

Press-fit versus threaded acetabular cups in total hip arthroplasty: Functional and radiological results after five years.

PubMed

Ellenrieder, Martin; Bader, Rainer; Bergschmidt, Philipp; Mittelmeier, Wolfram

2016-03-01

Prospectively the outcome after total hip replacement with a new threaded acetabular cup design was compared to an established press-fit cup. After 1, 2 and 5 years, the 36-item Short Form Health Survey, Western Ontario and McMaster University Osteoarthritis Index and Harris Hip Score revealed no significant differences between the two groups (each group: n=42 patients), except for a higher Harris Hip Score in the threaded cup group after five years (p=0.02). After five years, one threaded cup had a mild radiolucent line without further signs of loosening. All other cups of both groups (98.6%) showed a full osseous integration. The cup inclination angle ranged from 41-58° (threaded cups) to 39-77° (press-fit cups). The new threaded cup provides equivalent clinical outcomes and osseous integration but more precise implant positioning compared to the press-fit design. No complications typically ascribed to threaded cups (acetabular fractures, bone resorption, nerve impairment) occurred.

Hip2Norm: an object-oriented cross-platform program for 3D analysis of hip joint morphology using 2D pelvic radiographs.

PubMed

Zheng, G; Tannast, M; Anderegg, C; Siebenrock, K A; Langlotz, F

2007-07-01

We developed an object-oriented cross-platform program to perform three-dimensional (3D) analysis of hip joint morphology using two-dimensional (2D) anteroposterior (AP) pelvic radiographs. Landmarks extracted from 2D AP pelvic radiographs and optionally an additional lateral pelvic X-ray were combined with a cone beam projection model to reconstruct 3D hip joints. Since individual pelvic orientation can vary considerably, a method for standardizing pelvic orientation was implemented to determine the absolute tilt/rotation. The evaluation of anatomically morphologic differences was achieved by reconstructing the projected acetabular rim and the measured hip parameters as if obtained in a standardized neutral orientation. The program had been successfully used to interactively objectify acetabular version in hips with femoro-acetabular impingement or developmental dysplasia. Hip(2)Norm is written in object-oriented programming language C++ using cross-platform software Qt (TrollTech, Oslo, Norway) for graphical user interface (GUI) and is transportable to any platform.

Open reduction and internal fixation of osteoporotic acetabular fractures through the ilio-inguinal approach: use of buttress plates to control medial displacement of the quadrilateral surface.

PubMed

Peter, Robin E

2015-01-01

The number of acetabular fractures in the geriatric population requiring open reduction and internal fixation is increasing. Fractures with medial or anterior displacement are the most frequent types, and via the ilio-inguinal approach buttress plates have proved helpful to maintain the quadrilateral surface or medial acetabular wall. Seven to ten hole 3.5 mm reconstruction plates may be used as buttress plates, placed underneath the usual pelvic brim plate. This retrospective study presents our results with this technique in 13 patients at a minimum follow-up of 12 months (average, 31 months). 85% of the patients had a good result. The early onset of post-traumatic osteoarthritis necessitated total hip arthroplasty in two patients (15%) at 12 and 18 months follow-up, respectively. This treatment option should be considered in the surgeon's armamentarium when fixing these challenging cases. Copyright © 2015 Elsevier Ltd. All rights reserved.

Computed tomography vs. digital radiography assessment for detection of osteolysis in asymptomatic patients with uncemented cups: a proposal for a new classification system based on computer tomography.

PubMed

Sandgren, Buster; Crafoord, Joakim; Garellick, Göran; Carlsson, Lars; Weidenhielm, Lars; Olivecrona, Henrik

2013-10-01

Digital radiographic images in the anterior-posterior and lateral view have been gold standard for evaluation of peri-acetabular osteolysis for patients with an uncemented hip replacement. We compared digital radiographic images and computer tomography in detection of peri-acetabular osteolysis and devised a classification system based on computer tomography. Digital radiographs were compared with computer tomography on 206 hips, with a mean follow up 10 years after surgery. The patients had no clinical signs of osteolysis and none were planned for revision surgery. On digital radiographs, 192 cases had no osteolysis and only 14 cases had osteolysis. When using computer tomography there were 184 cases showing small or large osteolysis and only 22 patients had no osteolysis. A classification system for peri-acetabular osteolysis is proposed based on computer tomography that is easy to use on standard follow up evaluation. Copyright © 2013 Elsevier Inc. All rights reserved.

Survivorship analysis of failure pattern after revision total hip arthroplasty.

PubMed

Retpen, J B; Varmarken, J E; Jensen, J S

1989-12-01

Failure, defined as established indication for or performed re-revision of one or both components, was analyzed using survivorship methods in 306 revision total hip arthroplasties. The longevity of revision total hip arthroplasties was inferior to that of previously reported primary total hip arthroplasties. The overall survival curve was two-phased, with a late failure period associated with aseptic loosening of one or both components and an early failure period associated with causes of failure other than loosening. Separate survival curves for aseptic loosening of femoral and acetabular components showed late and almost simultaneous decline, but with a tendency toward a higher rate of failure for the femoral component. No differences in survival could be found between the Stanmore, Lubinus standard, and Lubinus long-stemmed femoral components. A short interval between the index operation and the revision and intraoperative and postoperative complications were risk factors for early failure. Young age was a risk factor for aseptic loosening of the femoral component. Intraoperative fracture of the femoral shaft was not a risk factor for secondary loosening. No difference in survival was found between primary cemented total arthroplasty and primary noncemented hemiarthroplasty.

Survivorship of the native hip joint after percutaneous repair of acetabular fractures in the elderly.

PubMed

Gary, Joshua L; Lefaivre, Kelly A; Gerold, Frank; Hay, Michael T; Reinert, Charles M; Starr, Adam J

2011-10-01

Our purpose was to examine survivorship of the native hip joint in patients ages 60 and over who underwent percutaneous reduction and fixation of acetabular fractures. A retrospective review at a University Level I Trauma Center was performed. Our institutional trauma database was reviewed. Patients aged 60 or older treated with percutaneous reduction and fixation of acetabular fractures between 1994 and 2007 were selected. 79 consecutive patients with 80 fractures were identified. Rate of conversion to total hip arthroplasty were used to construct a Kaplan-Meier curve showing survivorship of the native hip joint after treatment. 75 fractures had adequate clinical follow-up with a mean of 3.9 years (range 0.5-11.9 years). Average blood loss was 69 cc and there were no postoperative infections. 19/75 (25%) were converted to total hip arthroplasty at a mean time of 1.4 years after the index procedure. Survivorship analysis demonstrated a cumulative survival of 65% at 11.9 years of follow-up. There were no conversions to arthroplasty beyond 4.7 years postoperatively. There were no statistically significant associations between conversion to arthroplasty and age, sex, closed vs. limited open reduction, and simple vs. complex fracture pattern. Percutaneous fixation is a viable treatment option for patients age 60 or greater with acetabular fractures. Rates of conversion to total hip arthroplasty are comparable to open treatment methods and if conversion is required, soft tissues are preserved for future surgery. Copyright © 2010 Elsevier Ltd. All rights reserved.

[Osteosynthesis and cup revision in periprosthetic acetabulum fractures using a Kocher-Langenbeck approach].

PubMed

Schwabe, P; Märdian, S; Perka, C; Schaser, K-D

2016-04-01

Reconstruction/stable fixation of the acetabular columns to create an adequate periacetabular requirement for the implantation of a revision cup. Displaced/nondisplaced fractures with involvement of the posterior column. Resulting instability of the cup in an adequate bone stock situation. Periprosthetic acetabulum fractures with inadequate bone stock. Extended periacetabular defects with loss of anchorage options. Isolated periprosthetic fractures of the anterior column. Septic loosening. Dorsal approach. Dislocation of hip. Mechanical testing of inlaying acetabular cup. With unstable cup situation explantation of the cup, fracture fixation of acetabulum with dorsal double plate osteosynthesis along the posterior column. Cup revision. Hip joint reposition. Early mobilization; partial weight bearing for 12 weeks. Thrombosis prophylaxis. Clinical and radiological follow-ups. Periprosthetic acetabular fracture in 17 patients with 9 fractures after primary total hip replacement (THR), 8 after revision THR. Fractures: 12 due to trauma, 5 spontaneously; 7 anterior column fractures, 5 transverse fractures, 4 posterior column fractures, 1 two column fracture after hemiendoprosthesis. 5 type 1 fractures and 12 type 2 fractures. Operatively treated cases (10/17) received 3 reinforcement ring, 2 pedestal cup, 1 standard revision cup, cup-1 cage construct, 1 ventral plate osteosynthesis, 1 dorsal plate osteosynthesis, and 1 dorsal plate osteosynthesis plus cup revision (10-month Harris Hip Score 78 points). Radiological follow-up for 10 patients: consolidation of fractures without dislocation and a fixed acetabular cup. No revision surgeries during follow-up; 2 hip dislocations, 1 transient sciatic nerve palsy.

The influence of stem length and fixation on initial femoral component stability in revision total knee replacement

PubMed Central

Conlisk, N.; Gray, H.; Pankaj, P.; Howie, C. R.

2012-01-01

Objectives Orthopaedic surgeons use stems in revision knee surgery to obtain stability when metaphyseal bone is missing. No consensus exists regarding stem size or method of fixation. This in vitro study investigated the influence of stem length and method of fixation on the pattern and level of relative motion at the bone–implant interface at a range of functional flexion angles. Methods A custom test rig using differential variable reluctance transducers (DVRTs) was developed to record all translational and rotational motions at the bone–implant interface. Composite femurs were used. These were secured to permit variation in flexion angle from 0° to 90°. Cyclic loads were applied through a tibial component based on three peaks corresponding to 0°, 10° and 20° flexion from a normal walking cycle. Three different femoral components were investigated in this study for cementless and cemented interface conditions. Results Relative motions were found to increase with flexion angle. Stemmed implants reduced relative motions in comparison to stemless implants for uncemented constructs. Relative motions for cemented implants were reduced to one-third of their equivalent uncemented constructs. Conclusions Stems are not necessary for cemented implants when the metaphyseal bone is intact. Short cemented femoral stems confer as much stability as long uncemented stems. PMID:23610659

Increased Mortality in Elderly Patients with Sarcopenia and Acetabular Fractures.

PubMed

Deren, Matthew E; Babu, Jacob; Cohen, Eric M; Machan, Jason; Born, Christopher T; Hayda, Roman

2017-02-01

Sarcopenia is a condition of clinically relevant loss of muscle mass and function. Acetabular fractures in elderly patients are common and difficult to treat. This study aimed to determine if sarcopenia is common in elderly patients with acetabular fractures and correlates with lower-energy mechanisms of injury, higher rates of complications, and higher mortality than patients with normal muscle mass. The Rhode Island Hospital Trauma Database was queried for patients who were ≥60 years of age from 2005 to 2014 using the International Classification of Diseases, Ninth Revision, code for closed acetabular fracture, 808.0. Charts were retrospectively reviewed for demographic data, operative intervention, mechanism of injury, mortality, comorbidities, and other factors. Computed tomography (CT) was used to determine the muscle cross-sectional area and to calculate the skeletal muscle index. The database revealed 192 patients coded for acetabular fracture; of these, 181 were correctly diagnosed. Ninety-nine patients had recorded body mass index (BMI) and adequate CT scans to measure the skeletal muscle index. Forty-two patients (42.4%) had sarcopenia, and 57 patients (57.6%) did not have sarcopenia. There were no significant differences in demographic characteristics between the groups with the exception of BMI and sex. BMI was higher in patients who did not have sarcopenia (31.7 kg/m) than it was in patients with sarcopenia (23.6 kg/m) (p < 0.001). Male sex was significantly greater (p = 0.0104) in patients with sarcopenia at 76.2% (32 of 42 patients) than in patients without sarcopenia at 50.9% (29 of 57 patients). Fractures in patients without sarcopenia were associated with a higher-energy mechanism of injury in 78.9% of cases compared with 52.4% of cases of patients with sarcopenia (p = 0.005). Sarcopenia was significantly associated (p = 0.0419) with increased 1-year mortality (28.6%) compared with the absence of sarcopenia (12.3%). This association was even stronger if in-hospital mortality was excluded (p = 0.00074). Finally, anterior column fractures were more likely (p = 0.017) to be sustained by patients with sarcopenia at 47.6% (20 patients) than by patients who did not have sarcopenia at 24.6% (14 patients). Sarcopenia is common in elderly patients with acetabular fractures and is associated with lower-energy mechanisms, anterior column fractures, and higher risk of 1-year mortality. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Reconstruction of the Shallow Acetabulum With a Combination of Autologous Bulk and Impaction Bone Grafting Fixed by Cement.

PubMed

Maruyama, Masaaki; Wakabayashi, Shinji; Ota, Hiroshi; Tensho, Keiji

2017-02-01

Acetabular bone deficiency, especially proximal and lateral deficiency, is a difficult technical problem during primary total hip arthroplasty (THA) in developmental dysplasia of the hip (DDH). We report a new reconstruction method using a medial-reduced cemented socket and additional bulk bone in conjunction with impaction morselized bone grafting (additional bulk bone grafting method). In a population of patients with acetabular dysplasia undergoing THA using a medial-reduced cemented socket and additional bulk bone with impacted morselized bone grafting, we evaluated (1) the radiographic appearance of bone graft; (2) the proportion of cups that developed loosening and subsequent revision; and (3) clinical results (outcome scores and complications). Forty percent of 330 THAs for DDH performed at one center between 1999 and 2009 were defined as shallow dysplastic hips. The additional bulk bone grafting method was performed on 102 THAs with shallow acetabulum (31% for DDH) at one center between 1999 and 2009. We used this approach and technique for shallow acetabuli when a cup protruded from the lateral acetabular edge in preoperative templating. The other 132 dysplastic hips without bone grafting had THA performed at the same periods and served as a control. Acetabuli were defined as shallow when the depth was less than or equal to one-fifth of the pelvic height (cranial-caudal length on radiograph). The additional bulk bone grafting technique was as follows: the resected femoral head was sectioned at 1 to 2 cm thickness, and a suitable size of the bulk bone graft was placed on the lateral iliac cortex and fixed by poly-L-lactate absorbable screws. Autologous impaction morselized bone grafting, with or without hydroxyapatite granules, was performed along with the implantation of a medial-reduced cemented socket. We defined an "incorporated" graft as remodeling and trabeculation including rounding off of the protruding edge of a graft beyond the socket. Radiographic criteria used for determining loosening were migration or a continuous radiolucent zone between the prosthesis/bone cement and host bone. Clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA) and the Merle d'Aubigne and Postel score; complications were tallied from chart review. The followup was 10 ± 3 years (range, 6-15 years). One acetabular component (1%) with severe shallow and steep acetabuli showed definite radiographic evidence of loosening and was revised. Clinically, the mean JOA score for the hips treated with additional bulk bone grafting THA in this study improved from 39 ± 10 points preoperatively to 95 ± 5 points postoperatively (p < 0.05, paired t-test). The mean Merle d'Aubigne and Postel score for the hips improved from 7 ± 2 points to 17 ± 1 points (p < 0.05, paired t-test). Complications included a Trendelenburg sign in one hip, dislocation in one, and transient partial sciatic nerve palsy in one. Within 3 years 6 months postoperatively, 101 of 102 additional bulk bone grafting cases showed successful bone remodeling and bone graft reorientation without collapse on radiographs. Partial resorption of the additional bone graft on the lateral side was observed in two hips (2%) with socket abduction angles of < 35°. Achieving stable acetabular fixation is often challenging in the dysplastic hip, especially shallow acetabulum, and a variety of techniques have been described. Early results of combining bulk graft with impaction of morselized graft are promising. Although each surgical technique was well established, further investigation for clinical results of a combination of these techniques might be necessary to confirm longer term outcomes. Level IV, therapeutic study.

The Frank Stinchfield Award: the impact of socioeconomic factors on outcome after THA: a prospective, randomized study.

PubMed

Allen Butler, R; Rosenzweig, Seth; Myers, Leann; Barrack, Robert L

2011-02-01

Most studies of total hip arthroplasty (THA) focus on the effect of the type of implant on the clinical result. Relatively little data are available on the impact of the patient's preoperative status and socioeconomic factors on the clinical results following THA. We determined the relative importance of patient preoperative and socioeconomic status compared to implant and technique factors in predicting patient outcome as reflected by scores on commonly utilized rating scales (eg, Harris Hip Score, WOMAC, SF-12, degree of patient satisfaction, or presence or severity of thigh pain) following cementless THA. All patients during the study period were offered enrollment in a prospective, randomized study to receive either a titanium, tapered, proximally coated stem; or a Co-Cr, cylindrical, extensively coated stem; 102 patients were enrolled. We collected detailed patient data preoperatively including diagnosis, age, gender, insurance status, medical comorbidities, tobacco and alcohol use, household income, educational level, and history of treatment for lumbar spine pathology. Clinical evaluation included Harris Hip Score, SF-12, WOMAC, pain drawing, and UCLA activity rating and satisfaction questionnaire. Implant factors included stem type, stem size, fit in the canal, and stem-bone stiffness ratios. Minimum 2 year followup was obtained in 95% of the enrolled patients (102 patients). Patient demographics and preoperative status were more important than implant factors in predicting the presence of thigh pain, dissatisfaction, and a low hip score. The most predictive factors were ethnicity, educational level, poverty level, income, and a low preoperative WOMAC score or preoperative SF-12 mental component score. No implant parameter correlated with outcome or satisfaction. Socioeconomic factors and preoperative status have more impact on the clinical outcome of cementless THA than implant related factors. Level I, prospective, randomized clinical trial. See the guidelines online for a complete description of level of evidence.

Protrusio acetabuli in sickle-cell anemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez, S.; Apple, J.S.; Baber, C.

1984-04-01

Of 155 adults with sickle-cell anemia (SS, SC), radiographs of the pelvis or hip demonstrated protrusio acetabuli on at least one side in 14 (3 men and 11 women), as indicated by projection of the acetabular line medial to the ilio-ischial line. All 14 patients had bone changes attributable to sickle-cell anemia, including marrow hyperplasia and osteonecrosis; however, the severity of femoral or acetabular osteonecrosis did not appear directly related to the protrusion. The authors conclude that sickle-cell anemia can predispose to development of protrusio acetabuli.

Evaluating the accuracy of wear formulae for acetabular cup liners.

PubMed

Wu, James Shih-Shyn; Hsu, Shu-Ling; Chen, Jian-Horng

2010-02-01

This study proposes two methods for exploring the wear volume of a worn liner. The first method is a numerical method, in which SolidWorks software is used to create models of the worn out regions of liners at various wear directions and depths. The second method is an experimental one, in which a machining center is used to mill polyoxymethylene to manufacture worn and unworn liner models, then the volumes of the models are measured. The results show that the SolidWorks software is a good tool for presenting the wear pattern and volume of a worn liner. The formula provided by Ilchmann is the most suitable for computing liner volume loss, but is not accurate enough. This study suggests that a more accurate wear formula is required. This is crucial for accurate evaluation of the performance of hip components implanted in patients, as well as for designing new hip components.

Digital templating for THA: a simple computer-assisted application for complex hip arthritis cases.

PubMed

Hafez, Mahmoud A; Ragheb, Gad; Hamed, Adel; Ali, Amr; Karim, Said

2016-10-01

Total hip arthroplasty (THA) is the standard procedure for end-stage arthritis of the hip. Its technical success relies on preoperative planning of the surgical procedure and virtual setup of the operative performance. Digital hip templating is one methodology of preoperative planning for THA which requires a digital preoperative radiograph and a computer with special software. This is a prospective study involving 23 patients (25 hips) who were candidates for complex THA surgery (unilateral or bilateral). Digital templating is done by radiographic assessment using radiographic magnification correction, leg length discrepancy and correction measurements, acetabular component and femoral component templating as well as neck resection measurement. The overall accuracy for templating the stem implant's exact size is 81%. This percentage increased to 94% when considering sizing within 1 size. Digital templating has proven effective, reliable and essential technique for preoperative planning and accurate prediction of THA sizing and alignment.

Is labral hypotrophy correlated with increased acetabular depth?

PubMed Central

Toft, Felix; Anliker, Elmar; Beck, Martin

2015-01-01

Labral hypertrophy is a distinct feature in hip dysplasia. Occasionally, very small, hypotrophic labra are observed. However, there is no literature concerning this pathology. We investigated if the size of the labrum correlated with any radiologic parameters reflecting the amount of acetabular coverage. It was hypothezised that there is a negative correlation between labrum size and acetabular coverage. Labra were categorized into three groups depending on the relation between length of the articular sided surface and height of bony attachment. Labra with a height:length ratio of 2 were classified as hypotrophic, with a height:length ratio of 1 as normal and with a ratio of 0.5 as hypertrophic. Labral cross-sectional areas (CSA) were measured on radial magnetic resonance imaging-arthrography slices using the measuring tool of the PACS system of 20 hips with hypotrophic labra (group 1), 20 hips with normal labral appearance (group 2) and 10 hips with hypertrophic labra (group 3). These values were then analyzed against following parameters: neck-shaft-angle (NSA), lateral center-edge angle (LCE), acetabular index (AI), femoral extrusion index (FEI) and acetabular retroversion index (ARI). Analyses of variance were used to determine differences in mean values between the three groups. Mean labral CSA differed significantly between all groups (group 1: 12.1 ± 2.9 mm2; group 2: 25.2 ± 6.2 mm2; group 3: 41.1 ± 12.3 mm2; P < 0.001). NSA, LCE, AI and FEI all showed a significant difference between group 3 and 1 or 2. The ARI showed no difference between groups. Stepwise linear regression analyses showed a significant correlation between LCE angle and labral CSA with a corrected R2-value of 0.301. Labral CSA correlates with the LCE. No statistically significant difference between groups 1 and 2 concerning the LCE, AI or FEI could be identified. Nevertheless, group 1 had the highest mean coverage of all groups, hips with hypertrophic labra the lowest. PMID:27011836

Is transverse acetabular ligament an anatomical landmark to reliably orient the cup in primary total hip arthroplasty?

PubMed

Viste, A; Chouteau, J; Testa, R; Chèze, L; Fessy, M-H; Moyen, B

2011-05-01

Accurate positioning of the acetabular cup in primary total hip arthroplasty is critical to decrease the rate of dislocation. Inaccurate orientation of the cup is the most common error during this procedure. Target acetabular orientation is still controversial. An original study found a dislocation rate of 0.6% when the cup was aligned with the transverse acetabular ligament (TAL). TAL is a patient-specific anatomical landmark and a tool for cup orientation. Eight cadaveric pelves (14 hips included for study) were harvested in toto at our research laboratory. Anatomical versions of the TAL, labrum and horns were measured in relation to the anterior pelvic plane. A navigator sensor and an optoelectronic device (Motion Analysis™) were used. Anatomical versions of the TAL, horns and labrum averaged 1.9° (range, -8° to +13.3°), 3° (range, -12.2° to 14°), and 26.3° (range, 17.4° to 41.8°), respectively. To our knowledge, this is the first study to report the orientation of the periacetabular soft-tissues. TAL anteversion was outside the safe zone described by Lewinnek, while labrum anteversion was within this safe-zone. We discuss the reference used, Lewinnek's safe zone, and functional orientation of the implants. Lewinnek's safe-zone does not seem to be valid. The TAL seems to be a specific reference for each patient but its reliability must still be confirmed as an adequate reference for positioning the cup in total hip arthroplasty. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

A case report of the management and the outcome of a complete epiphyseal separation and dislocation with left anterior column fracture of the acetabulum.

PubMed

Palencia, Jesús; Alfayez, Saud; Serro, Firas; Alqahtani, Jamal; Alharbi, Hani; Alhinai, Hamed

2016-01-01

Femoral head and neck fractures in children are uncommon, accounting for fewer than 1% of all pediatric fractures and fewer than 8% of all hip fractures. Furthermore, traumatic transphyseal hip fracture is rare to present in daily practice especially when associated with an acetabular fracture. A twelve years old boy, not known to have any chronic illnesses, presented to the emergency department as a case of polytrauma after a road traffic accident. Signs of left hip dislocation were discovered upon physical examination. X-rays and CT scans, revealed a complete transphyseal posterior dislocation and a left anterior column fracture of the acetabulum with a minimal displacement. Within five hours, the patient underwent open reduction and internal fixation by two cannulated screws. The acetabular fracture was managed conservatively. After six months, there were clear signs of osteonecrosis of the femoral head. A high-energy trauma in children and adolescents can lead to simultaneous epiphyseal and acetabular fractures which are associated with a poor prognosis. The age seems to play a role as patients older than ten years have a higher risk of developing AVN after sustaining a hip dislocation regardless of the time of intervention. Epiphyseal fracture with dislocation of the femoral head is rare among children and adolescents, especially when associated with an acetabular fracture. AVN in such cases can develop, and it represents a challenge to orthopedic surgeons due to the poor prognosis and the future functional limitations of the joint. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

[Modified PemberSal osteotomy technique with lyophilized human allograft].

PubMed

Druschel, C; Heck, K; Kraft, C; Placzek, R

2016-12-01

PemberSal osteotomy to improve femoral head coverage by rotating the acetabular roof ventrally and laterally. Insufficient coverage of the femoral head, and can be combined with other surgical procedures such as femoral intertrochanteric varus-derotation osteotomy and open reduction for developmental dysplasia and dislocation of the hip or to improve sphericity and containment in Legg-Calvé-Perthes disease. This specific acetabuloplasty can only be performed in patients with an open epiphyseal growth-plate. Increased bleeding tendency (e.g., inherited or iatrogenic); elevated anesthetic risk such as in cerebral palsy, arthrogryposis multiplex congenital, trisomies; syndromes require explicit interdisciplinary clarification to reduce perioperative risks; infections as in other elective surgeries; diseases/deformities making postoperative spica casting impossible or impractical (e.g., deformities of spinal cord or urogenital system, hernias requiring treatment); closed epiphyseal plate requires complex three-dimensional corrections of the acetabular roof (e.g., triple/periacetabular osteotomy). Osteotomy from the iliac bone to the posterior ilioischial arm of the epiphyseal growth-plate cartilage; controlled fracture of the cancellous bone without breaking the medial cortex of the iliac bone for ventrocaudal rotation of the acetabular roof. To refill and stabilize the osteotomy site, an allogenic bone-wedge is interponated and secured by a resorbable screw or kirschner wire. This method also allows more complex reconstructions of the acetabular roof, e.g., by including the pseudo-cup in a modified Rejholec technique. A spica cast is applied to immobilize the hip for 6 weeks. Afterwards physiotherapy can be performed under weight-bearing as tolerated. Radiographic check-ups every 6 months.

Variation in Treatment of Displaced Geriatric Acetabular Fractures Among 15 Level-I Trauma Centers.

PubMed

Manson, Theodore T; Reider, Lisa; OʼToole, Robert V; Scharfstein, Daniel O; Tornetta, Paul; Gary, Joshua L

2016-09-01

To document the initial treatment of displaced acetabular fractures among older adults across multiple trauma centers and to investigate the factors that influence the decision to operate and the choice of operative procedure [open reduction internal fixation (ORIF) vs. total hip arthroplasty (THA)]. Retrospective observational study. Fifteen US level-I trauma centers participating in the Major Extremity Trauma Research Consortium. Overall, 269 patients aged 60 years or older admitted for the treatment of a displaced acetabular fracture. None. Treatment. Sixty percent of fractures (n = 162) were treated operatively. Younger age (<80 years), injury from high-energy mechanism, fractures with femoral head impaction, and fractures without hip congruency were significantly associated with receiving operative treatment (P < 0.05). Significant site variation in operative versus nonoperative treatment occurred even after accounting for these factors (P = 0.0044). Among operatively treated patients, 88% (n = 142) received ORIF and 12% (n = 20) received THA as the initial treatment. Women were more likely to be treated with initial THA compared with men; of the known risk factors for poor outcomes with ORIF (ie, dome or roof impaction, femoral head impaction, or posterior wall involvement), only dome impaction was significantly associated with receiving initial THA (P < 0.05). Currently, no treatment guidelines exist for acetabular fractures in older adults, which likely explains the significant site variation in operative versus nonoperative treatment. This study identifies patient and injury factors that drive treatment decisions, which will be important in planning and designing future trials needed to determine the best treatment for these fractures.

Radiological findings for hip dysplasia at skeletal maturity. Validation of digital and manual measurement techniques.

PubMed

Engesæter, Ingvild Øvstebø; Laborie, Lene Bjerke; Lehmann, Trude Gundersen; Sera, Francesco; Fevang, Jonas; Pedersen, Douglas; Morcuende, José; Lie, Stein Atle; Engesæter, Lars Birger; Rosendahl, Karen

2012-07-01

To report on intra-observer, inter-observer, and inter-method reliability and agreement for radiological measurements used in the diagnosis of hip dysplasia at skeletal maturity, as obtained by a manual and a digital measurement technique. Pelvic radiographs from 95 participants (56 females) in a follow-up hip study of 18- to 19-year-old patients were included. Eleven radiological measurements relevant for hip dysplasia (Sharp's, Wiberg's, and Ogata's angles; acetabular roof angle of Tönnis; articulo-trochanteric distance; acetabular depth-width ratio; femoral head extrusion index; maximum teardrop width; and the joint space width in three different locations) were validated. Three observers measured the radiographs using both a digital measurement program and manually in AgfaWeb1000. Inter-method and inter- and intra-observer agreement were analyzed using the mean differences between the readings/readers, establishing the 95% limits of agreement. We also calculated the minimum detectable change and the intra-class correlation coefficient. Large variations among different radiological measurements were demonstrated. However, the variation was not related to the use of either the manual or digital measurement technique. For measurements with greater absolute values (Sharp's angle, femoral head extrusion index, and acetabular depth-width ratio) the inter- and intra-observer and inter-method agreements were better as compared to measurements with lower absolute values (acetabular roof angle, teardrop and joint space width). The inter- and intra-observer variation differs notably across different radiological measurements relevant for hip dysplasia at skeletal maturity, a fact that should be taken into account in clinical practice. The agreement between the manual and digital methods is good.

Acetabular labral tears with underlying chondromalacia: a possible association with high-level running.

PubMed

Guanche, Carlos A; Sikka, Robby S

2005-05-01

The use of hip arthroscopy has helped delineate intra-articular pathology and has enabled clinicians to further elucidate the factors responsible for injuries, such as running. The subtle development of degenerative changes may be a result of repetitive impact loading associated with this sport. This study presents a population of runners with common pathologic acetabular changes. Case series. Eight high-level runners with an average age of 36 years (range, 19 to 45 years) were seen for complaints of increasing hip pain with running without any history of macrotrauma. All of the patients had either run several marathons (4), were triathletes (1), Olympic middle distance runners (1), or had run more than 10 miles per week for longer than 5 years (2). Plain radiographic analysis revealed no degenerative changes and an average center-edge (CE) angle of 36.7 degrees (range, 28 degrees to 44 degrees). All patients underwent hip arthroscopy with labral debridement. In 6 patients (75%), a chondral injury of the acetabular cartilage underlying the labral tear was noted. In addition, 3 patients had ligamentum teres disruptions. It is possible that the development of these tears is the result of subtle instability, which may be exacerbated by running, eventually leading to labral tearing and possible ligamentum teres disruption. While perhaps concurrently, subtle acetabular dysplasia may play a role. Although this study does not confirm an association between running and the development of labral tears or chondral lesions in the hip, it certainly questions whether there is an injury pattern common to this population, a "runner's hip." Level IV.

Obstacles to reduction in infantile developmental dysplasia of the hip.

PubMed

Studer, K; Williams, N; Studer, P; Baker, M; Glynn, A; Foster, B K; Cundy, P J

2017-10-01

Identification of anatomical structures that block -reduction in developmental dysplasia of the hip (DDH) is -important for the management of this challenging condition. Obstacles to reduction seen on arthrogram are well-known. However, despite the increasing use of MRI in the assessment of adequacy of reduction in DDH, the interpretation of MRI patho-anatomy is ill-defined with a lack of relevant literature to guide clinicians. This is a retrospective analysis of the MRI of patients with DDH treated by closed reduction over a five-year period (between 2009 and 2014). Neuromuscular and genetic disorders were excluded. Each MRI was analysed by two orthopaedic surgeons and a paediatric musculoskeletal radiologist to identify the ligamentum teres, pulvinar, transverse acetabular ligament (TAL), capsule, labrum and acetabular roof cartilage hypertrophy. Inter- and intraobserver reliability was calculated. The minimum follow-up was 12 months. A total of 29 patients (38 hips) underwent closed reduction for treatment of DDH. Eight hips showed persistent subluxation on post-operative MRI. Only three of these eight hips showed an abnormality on arthrogram. The pulvinar was frequently interpreted as 'abnormal' on MRI. The main obstacles identified on MRI were the ligamentum teres (15.8%), labrum (13.1%) and acetabular roof cartilage hypertrophy (13.2%). The inter-rater reliability was good for TAL, capsule and pulvinar; moderate for ligamentum teres and labrum; and poor for hypertrophied cartilage. The labrum, ligamentum teres and acetabular roof cartilage hypertrophy are the most important structures seen on MRI preventing complete reduction of DDH. Focused interpretation of these structures may assist in the management of DDH.

Is the evaluation of the anterior inferior iliac spine (AIIS) in the AP pelvis possible? Analysis of conventional X-rays and 3D-CT reconstructions.

PubMed

Krueger, David R; Windler, Markus; Geßlein, Markus; Schuetz, Michael; Perka, Carsten; Schroeder, Joerg H

2017-07-01

A hypertrophic AIIS has been identified as a cause for extraarticular hip impingement and is classified according to Hetsroni using 3D-CT reconstructions. The role of the conventional AP pelvis X-ray, which is the first standard imaging step for the evaluation of hip pain, has not been investigated yet. AP pelvis X-rays and 3D-CT reconstructions of patients were evaluated regarding their morphology of the AIIS. The conventional X-rays were categorized into three groups according to the projection of the AIIS: above (A) or below (B) the acetabular sourcil or even exceeding the anterior acetabular rim (C). They were compared to the morphologic types in the 3D-CT reconstruction (Hetsroni type I-III). Ninety patients with an equal distribution of type A, B or C projection in the AP pelvis were evaluated and compared to the morphology in the 3D-CT reconstruction. The projection of the AIIS below the acetabular sourcil (B + C) showed only moderate sensitivity (0.76) and specificity (0.64) for a hypertrophic AIIS (Hetsroni type II + III), but if the AIIS exceeds the anterior rim, all cases showed a hypertrophic AIIS in the 3D-CT reconstructions (Hetsroni type II + III). Distinct differentiation of the AIIS morphology in the AP pelvis is not possible, but the projection of the AIIS below the anterior acetabular rim represented a hypertrophic AIIS in all cases and should, therefore, be critically investigated for a relevant AIIS impingement.

[Acetabular anteversion angle of the hip in the Mexican adult population measured with computed tomography].

PubMed

Rubalcava, J; Gómez-García, F; Ríos-Reina, J L

2012-01-01

Knowledge of the radiogrametric characteristics of a specific skeletal segment in a healthy population is of the utmost clinical importance. The main justification for this study is that there is no published description of the radiogrametric parameter of acetabular anteversion in a healthy Mexican adult population. A prospective, descriptive and cross-sectional study was conducted. Individuals of both genders older than 18 years and orthopedically healthy were included. They underwent a two-dimensional axial tomographic study of both hips to measure the acetabular anteversion angles. The statistical analysis consisted of obtaining central trend and scatter measurements. A multivariate analysis of variance (ANOVA) and statistical significance were performed. 118 individuals were studied, 60 males and 58 females, with a mean age of 47.7 +/- 16.7, and a range of 18-85 years. The anteversion of the entire group was 18.6 degrees + 4.1 degrees. Anteversion in males was 17.3 degrees +/- 3.5 degrees (10 degrees - 25 degrees) and in females 19.8 degrees +/- 4.7 degrees (10 degrees - 31 degrees). There were no statistically significant differences (p < or = 0.05) in right and left anteversion in the entire group. However, there were statistically significant differences (p > or = 0.005) both in the right and left sides when males and females were compared. Our study showed that there are great variations in the anteversion ranges of a healthy population. When our results are compared with those published by other authors the mean of most measurements exceeds 15 degrees. This should be useful to make therapeutic decisions that involve acetabular anteversion.

Computer-aided designed, three dimensional-printed hemipelvic prosthesis for peri-acetabular malignant bone tumour.

PubMed

Wang, Baichuan; Hao, Yongqiang; Pu, Feifei; Jiang, Wenbo; Shao, Zengwu

2018-03-01

Prosthetic reconstruction may be a promising treatment for peri-acetabular malignant bone tumour; however, it is associated with a high complication rate. Therefore, prosthetic design and approach of prosthetic reconstruction after tumour resection warrant study. We retrospectively analyzed 11 patients with peri-acetabular malignant bone tumours treated by personalized 3D-printed hemipelvic prostheses after en bloc resection between 2015 and 2016. Pre-operative and post-operative pain at rest was assessed according to a 10-cm VAS score. The results of functional improvement were evaluated using the MSTS-93 score at the final follow-up. We also analyzed tumour recurrence, metastases, and complications associated with the reconstruction procedure. All patients were observed for six to 24 months with an average follow-up of 15.5 months. One patient had occasional pain of the involved hip at the final follow-up (VAS, pre vs. post 8 months: 3 vs. 2). The mean MSTS-93 score was 19.2 (range, 13-25). Hip dislocation was detected in two patients, while delayed wound healing occurred in one patient. One patient with mesenchymal chondrosarcoma had a left iliac bone metastasis. Local tumour recurrence was not observed. Reconstruction of bony defect after tumour resection using personalized 3D-printed hemipelvic prostheses can obtain acceptable functional results without severe complications. Based on previous reports and our results, we believe that reconstruction arthroplasty using 3D-printed hemipelvic prostheses will provide a promising alternative for those patients with peri-acetabular malignant bone tumours. Level IV, therapeutic study.

Lateral Compression-I Pelvic Ring Injury: Not Benign to the Developing Fetus.

PubMed

Weinlein, John C; Mashru, Rakesh P; Perez, Edward A; Johnson, Sara E

2018-02-01

To determine whether certain patterns of pelvic ring injury are associated with more frequent intrauterine fetal demise (IUFD). Retrospective review. Level 1 trauma center. Of 44 pregnant patients with pelvic and/or acetabular fractures, 40 had complete records that allowed determination of fetal viability. χ2 tests were used for categorical variables (Fisher exact tests when expected cell counts were fewer than 5), and t tests were used for continuous variables. Fetal or maternal death. Sixteen patients had isolated acetabular fractures, 25 had isolated pelvic ring injuries, and 3 had acetabular fractures with concomitant pelvic ring injuries. Maternal and fetal mortality were 2% and 40%, respectively. No patients with isolated acetabular fractures experienced IUFD, compared with 68% (15/22) of those with isolated pelvic ring injuries (P < 0.0001). Eight (53%) of 15 IUFDs were associated with lateral compression (LC)-I pelvic ring injuries (Orthopaedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen 61-B2). Of the 13 LC-I pelvic ring injuries, 8 (62%) resulted in IUFD. Pelvic ring stability, Young-Burgess classification, and operative treatment were not associated with IUFD. Maternal Glasgow Coma Scale (average 13.2) and Injury Severity Score (average 18.2) at admission were predictive of IUFD. The most frequent pelvic fractures in gravid trauma patients are LC-I. Although the rate of maternal mortality was low, the risk of IUFD was quite high (40%). LC-I pelvic ring injuries often had catastrophic outcomes, with IUFD in 62% of cases. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Dynamic RSA for the evaluation of inducible micromotion of Oxford UKA during step-up and step-down motion.

PubMed

Horsager, Kristian; Kaptein, Bart L; Rømer, Lone; Jørgensen, Peter B; Stilling, Maiken

2017-06-01

Background and purpose - Implant inducible micromotions have been suggested to reflect the quality of the fixation interface. We investigated the usability of dynamic RSA for evaluation of inducible micromotions of the Oxford Unicompartmental Knee Arthroplasty (UKA) tibial component, and evaluated factors that have been suggested to compromise the fixation, such as fixation method, component alignment, and radiolucent lines (RLLs). Patients and methods - 15 patients (12 men) with a mean age of 69 (55-86) years, with an Oxford UKA (7 cemented), were studied after a mean time in situ of 4.4 (3.6-5.1) years. 4 had tibial RLLs. Each patient was recorded with dynamic RSA (10 frames/second) during a step-up/step-down motion. Inducible micromotions were calculated for the tibial component with respect to the tibia bone. Postoperative component alignment was measured with model-based RSA and RLLs were measured on screened radiographs. Results - All tibial components showed inducible micromotions as a function of the step-cycle motion with a mean subsidence of up to -0.06 mm (95% CI: -0.10 to -0.03). Tibial component inducible micromotions were similar for cemented fixation and cementless fixation. Patients with tibial RLLs had 0.5° (95% CI: 0.18-0.81) greater inducible medio-lateral tilt of the tibial component. There was a correlation between postoperative posterior slope of the tibial plateau and inducible anterior-posterior tilt. Interpretation - All patients had inducible micromotions of the tibial component during step-cycle motion. RLLs and a high posterior slope increased the magnitude of inducible micromotions. This suggests that dynamic RSA is a valuable clinical tool for the evaluation of functional implant fixation.

Medium-term outcome in patients treated with total hip arthroplasty using a modular femoral stem.

PubMed

Dagnino, Augusto; Grappiolo, Guido; Benazzo, Franco M; Learmonth, Ian D; Spotorno, Lorenzo; Portinaro, Nicola

2012-01-01

The clinical, radiographic and quality of life results of total hip arthroplasty using the MODULUS cementless modular femoral stem were reviewed. 48 patients who had a total hip arthroplasty using the MODULUS femoral stem were identified. Six had bilateral procedures, resulting in 60 hips with complete clinical and radiographic data. Mean age at implantation was 50 years (range 33 to 82). Mean follow-up was 59 months (range 50 months to 73). There were two early post-operative dislocations (within 2 days). One patient required further surgery to remove heterotopic bone. Mean Harris Hip Score increased from 37 points preoperatively (range, 7 to 66) to 89 points at final review (range, 65 to 100 points). Radiographic evaluation revealed that all implants were stable without evidence of osteolysis but three patients (5%) exhibited heterotopic ossification. Quality of life was evaluated with the SF36. The physical component increased from 29.2 points (range, 18.5 to 46.0) to 51.7 points (range 42.9 to 60.6) and the mental component from 375 points (range, 19.5 to 50.0) to 50 points (range 32,8 to 62.0).

The development and nature of femoral head cam lesions following acetabular fractures.

PubMed

Berber, Onur; Foote, Julian; Sabharwal, Sanjeeve; Datta, Gorav; Bircher, Martin D

2014-01-01

The aim of acetabular fracture fixation is to restore joint congruity with restoration of the articular surface. Poor outcomes are seen where this has not been achieved. Letournel reported a collarette osteophyte seen postoperatively in a proportion of patients, which he suggested was an early precursor to the development of osteoarthritis. This is a retrospective study of patients treated at a tertiary referral unit who developed this lesion. The triangular index was measured in 48 of these patients and then correlated with their clinical findings, Oxford Hip Score and the presence of osteoarthritis. Length of follow-up, fracture classification, and joint congruency were also recorded. Results showed a statistically significant relationship between cam lesion size and the development of osteoarthritis (P = 0.008), cam lesion size and length of follow-up (P = 0.01), and between groin pain and postoperative joint congruency (LR = 0.035). These findings suggest that the appearance of a cam lesion is a poor long-term prognostic marker for the development of osteoarthritis in patients with an acetabular fracture.

The design, production and clinical application of 3D patient-specific implants with drilling guides for acetabular surgery.

PubMed

Merema, B J; Kraeima, J; Ten Duis, K; Wendt, K W; Warta, R; Vos, E; Schepers, R H; Witjes, M J H; IJpma, F F A

2017-11-01

An innovative procedure for the development of 3D patient-specific implants with drilling guides for acetabular fracture surgery is presented. By using CT data and 3D surgical planning software, a virtual model of the fractured pelvis was created. During this process the fracture was virtually reduced. Based on the reduced fracture model, patient-specific titanium plates including polyamide drilling guides were designed, 3D printed and milled for intra-operative use. One of the advantages of this procedure is that the personalised plates could be tailored to both the shape of the pelvis and the type of fracture. The optimal screw directions and sizes were predetermined in the 3D model. The virtual plan was translated towards the surgical procedure by using the surgical guides and patient-specific osteosynthesis. Besides the description of the newly developed multi-disciplinary workflow, a clinical case example is presented to demonstrate that this technique is feasible and promising for the operative treatment of complex acetabular fractures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Examination of acetabular labral tear: a continued diagnostic challenge.

PubMed

Reiman, Michael P; Mather, Richard C; Hash, Thomas W; Cook, Chad E

2014-02-01

Acetabular labrum tears (ALT) are present in 22-55% of individuals with hip or groin pain. Tears can occur as a result of trauma or degeneration and are markedly associated with femoral acetabular morphological variations. An ALT can lead to biomechanical deficiencies and a loss of stability to the coxafemoral joint due to the labrum serving as a stabilising structure of this joint. The diagnosis of ALT is complex and multidimensional. Although tremendous improvements in diagnostic utility for ALT have occurred in the past 25 years, there are few patient history, clinical examination and special test findings that are unique to the condition. Imaging methods such as MRI, CT and ultrasonography have demonstrated reasonable accuracy, but not at a level that allows use as a stand-alone measure. Outcomes measures that focus on functional limitation or that are used to measure recovery should envelop the complexities of the condition and be captured using both self-report and physical performance measures. Only when patient history, objective testing, clinical examination special testing and imaging are combined can a clinician fully elucidate the multidimensional diagnosis of ALT.

Acceleration of Intended Pozzolanic Reaction under Initial Thermal Treatment for Developing Cementless Fly Ash Based Mortar.

PubMed

Kwon, Yang-Hee; Kang, Sung-Hoon; Hong, Sung-Gul; Moon, Juhyuk

2017-02-24

Without using strong alkaline solution or ordinary Portland cement, a new structural binder consisting of fly ash and hydrated lime was hardened through an intensified pozzolanic reaction. The main experimental variables are the addition of silica fume and initial thermal treatment (60 °C for 3 days). A series of experiments consisting of mechanical testing (compressive and flexural strength, modulus of elasticity), X-ray diffraction, and measurements of the heat of hydration, pore structure, and shrinkage were conducted. These tests show that this new fly ash-based mortar has a compressive strength of 15 MPa at 91 days without any silica fume addition or initial thermal treatment. The strength increased to over 50 MPa based on the acceleration of the intensified pozzolanic reaction from the silica fume addition and initial thermal treatment. This is explained by a significant synergistic effect induced by the silica fume. It intensifies the pozzolanic reaction under thermal treatment and provides a space filling effect. This improved material performance can open a new pathway to utilize the industrial by-product of fly ash in cementless construction materials.

Radiographic evaluation of BFX acetabular component position in dogs.

PubMed

Renwick, Alasdair; Gemmill, Toby; Pink, Jonathan; Brodbelt, David; McKee, Malcolm

2011-07-01

To assess the reliability of radiographic measurement of angle of lateral opening (ALO) and angle of version of BFX acetabular cups. In vitro radiographic study. BFX cups (24, 28, and 32 mm). Total hip replacement constructs (cups, 17 mm femoral head and a #7 CFX stem) were mounted on an inclinometer. Ventrodorsal radiographs were obtained with ALO varying between 21° and 70° and inclination set at 0°, 10°, 20°, and 30°. Radiographs were randomized using a random sequence generator. Three observers blinded to the radiograph order assessed ALO using 3 methods: (1) an ellipse method based on trigonometry; (2) using a measurement from the center of the femoral head to the truncated surface of the cup; (3) by visual estimation using a reference chart. Version was measured by assessing the ventral edge of the truncated surface. ALO methods 2 and 3 were accurate and precise to within 10° and were significantly more accurate and precise than method 1 (P < .001). All methods were significantly less accurate with increasing inclination. Version measurement was accurate and precise to within 7° with 0-20° of inclination, but significantly less accurate with 30° of inclination. Methods 2 and 3, but not method 1, were sufficiently accurate and precise to be clinically useful. Version measurement was clinically useful when inclination was ≤ 20°. © Copyright 2011 by The American College of Veterinary Surgeons.

Primary cementless total hip arthroplasty with second-generation metal-on-metal bearings: a concise follow-up, at a minimum of seventeen years, of a previous report.

PubMed

Lass, R; Grübl, A; Kolb, A; Domayer, S; Csuk, C; Kubista, B; Giurea, A; Windhager, R

2014-03-05

Second-generation, metal-on-metal bearings were introduced in 1988, to reduce wear and avoid polyethylene particle-induced osteolysis from total hip arthroplasty. In 2007, we reported the long-term results of ninety-eight patients (105 hips) who underwent primary cementless total hip arthroplasty involving the use of a prosthesis with a high-carbide-concentration, metal-on-metal articulating surface between November 1992 and May 1994. The present study gives an update on this patient cohort. At a minimum of seventeen years postoperatively, forty-nine patients (fifty-two hips) were available for follow-up examination. We retrospectively evaluated clinical and radiographic results as well as serum metal concentration. The mean patient age at the time of the index arthroplasty was fifty-six years. Three cups (6% of the hips) and one stem (2% of the hips) were revised because of aseptic loosening of the implants combined with focal osteolysis. At the time of the latest follow-up evaluation, the mean Harris hip score was 88.8 points, and the mean University of California Los Angeles (UCLA) activity score was 6.7 points. The cumulative rate of implant survival, with aseptic failure as the end point, was 93.0% at 18.8 years. The median serum cobalt concentration in patients whose hip implant was the only source of cobalt was 0.70 μg/L (range, 0.4 to 5.1 μg/L), showing no increase in the value as noted at a minimum of ten years of follow-up. The clinical and radiographic results of our study, which, to our knowledge, represent the longest duration of follow-up for a series of cementless total hip arthroplasties with use of a 28-mm metal-on-metal bearing, continue to be comparable with the results observed for other hard-on-hard bearings.

Variation in functional pelvic tilt in patients undergoing total hip arthroplasty.

PubMed

Pierrepont, J; Hawdon, G; Miles, B P; Connor, B O'; Baré, J; Walter, L R; Marel, E; Solomon, M; McMahon, S; Shimmin, A J

2017-02-01

The pelvis rotates in the sagittal plane during daily activities. These rotations have a direct effect on the functional orientation of the acetabulum. The aim of this study was to quantify changes in pelvic tilt between different functional positions. Pre-operatively, pelvic tilt was measured in 1517 patients undergoing total hip arthroplasty (THA) in three functional positions - supine, standing and flexed seated (the moment when patients initiate rising from a seated position). Supine pelvic tilt was measured from CT scans, standing and flexed seated pelvic tilts were measured from standardised lateral radiographs. Anterior pelvic tilt was assigned a positive value. The mean pelvic tilt was 4.2° (-20.5° to 24.5°), -1.3° (-30.2° to 27.9°) and 0.6° (-42.0° to 41.3°) in the three positions, respectively. The mean sagittal pelvic rotation from supine to standing was -5.5° (-21.8° to 8.4°), from supine to flexed seated was -3.7° (-48.3° to 38.6°) and from standing to flexed seated was 1.8° (-51.8° to 39.5°). In 259 patients (17%), the extent of sagittal pelvic rotation could lead to functional malorientation of the acetabular component. Factoring in an intra-operative delivery error of ± 5° extends this risk to 51% of patients. Planning and measurement of the intended position of the acetabular component in the supine position may fail to predict clinically significant changes in its orientation during functional activities, as a consequence of individual pelvic kinematics. Optimal orientation is patient-specific and requires an evaluation of functional pelvic tilt pre-operatively. Cite this article: Bone Joint J 2017;99-B:184-91. ©2017 The British Editorial Society of Bone & Joint Surgery.

[Use of the Omega plate for stabilisation of acetabular fractures: first experience].

PubMed

Šrám, J; Taller, S; Lukáš, R; Endrych, L

2013-01-01

The aim of our study is to solve the problem of insufficient fixation of comminuted fractures of the quadrilateral plane and the iliopectineal line. These fixation problems occur while using the standard narrow 3.5 mm fixation plate applied from a modified Stoppa approach. A new plate developed by the authors--the Omega plate--fulfils the requirements. In the period 2010-2012, we performed 156 stabilisations of pelvic ring fractures and acetabular fractures. We used the modified Stoppa approach applying the standard fixation plate in 24 patients and the Omega plate in 15 patients. The patient group with the Omega plate included 10 male and five female patients with the average age of 61 years (range, 30-72). Only 11 patients were followed up, with an average period of 13.3 months, because one patient was lost to followup and three patients were shortly after surgery. The surgical technique of Omega plate application is described in detail. The clinical evaluation of post-operative results was based on the Harris Hip Score; the graphical results were rated using the Matta and Pohlemann criteria. The Stoppa approach alone was used in four patients, combination of two approaches (Stoppa and Kocher-Langenbeck approach) was used in six cases and three approaches were employed in five patients. No adverse intra- or post-operative events were recorded. Excellent or satisfactory graphical results were obtained in 12 patients and an unsatisfactory graphical outcome was recorded in three cases. In the follow-up period ranging from 8 to 22 months, 11 patients healed. Late complications included avascular femoral head necrosis in two and severe post-traumatic coxarthrosis in three patients. Due to these complications, all five patients underwent total hip arthroplasty without previous Omega plate removal at an average interval of 15 months from the primary pelvic surgery. They were not included in the follow-up evaluation. The remaining six patients had an average Harris Hip Score of 88 points (range, 81-98). The novel plate, shaped as a reverse omega letter, enables fixation of the quadrilateral area of the acetabulum through pressure of the arc of the plate against this area. Hitches, with holes for screw insertion, attached to the Omega plate in its middle part allow for fixation of fragments above the linea arcuata simply by pressure. Hitches in the ventral part provide for plate fixation to the ventral acetabular column and the superior pubic ramus. Hitches in the posterior segment of the plate facilitate insertion of a long screw in the posterior acetabular column from an additional iliac approach for stabilisation of simple acetabular fractures. The Omega plates are manufactured in several modifications. The Omega plate enables us to fix fractures of the superior pubic ramus, fractures of the anterior acetabular column, fractures of the quadrilateral acetabular plate, fractures in the iliopectineal line and simple fractures of the posterior column. A CT-defined projection of the pelvic inlet based on pre-operative CT scans allows us to choose the appropriate plate size and to shape the plate pre-operatively. After a technically well performed Stoppa approach and good fragment reduction, the application of an Omega plate is easy if our recommendations are followed. Fixation of all fragments of the anterior column and the quadrilateral plate is very stable and the Omega plate is highly resistant to secondary loss of reduction. A potential total hip arthroplasty does not require Omega plate removal.

Restoration of the centre of rotation in primary total hip arthroplasty: the influence of acetabular floor depth and reaming technique.

PubMed

Meermans, G; Doorn, J Van; Kats, J-J

2016-12-01

One goal of total hip arthroplasty is to restore normal hip anatomy. The aim of this study was to compare displacement of the centre of rotation (COR) using a standard reaming technique with a technique in which the acetabulum was reamed immediately peripherally and referenced off the rim. In the first cohort the acetabulum was reamed to the floor followed by sequentially larger reamers. In the second cohort the acetabulum was only reamed peripherally, starting with a reamer the same size as the native femoral head. Anteroposterior pelvic radiographs were analysed for acetabular floor depth and vertical and horizontal position of the COR. Horizontally, the mean medial displacement of the COR was 0.8 mm (standard deviation (sd) 1.4) in the peripheral remaing group and 5.0 mm (sd 3.30) in the standard reaming group (p < 0.001). Vertically, the mean superior displacement of the COR was 0.7 mm (sd 1.3) in the peripheral reaming group and 3.7 mm (sd 2.6) in the standard reaming group (p < 0.001). In the standard reaming group, there was a strong correlation between the pre-operative acetabular floor depth and displacement of the COR (p < 0.001). Reaming the acetabulum to the floor can lead to significant displacement of the COR medially and superiorly. This displacement is related to the pre-operative acetabular floor depth and cannot always be compensated by using a high offset stem. Cite this article: Bone Joint J 2016;98-B:1597-603. ©2016 The British Editorial Society of Bone & Joint Surgery.

Cup press fit in uncemented THA depends on sex, acetabular shape, and surgical technique.

PubMed

García-Rey, Eduardo; García-Cimbrelo, Eduardo; Cruz-Pardos, Ana

2012-11-01

Uncemented press-fit cups provide bone fixation in primary THA, but the use of screws is sometimes necessary to achieve primary stability of the socket. However, it is unclear whether and when screws should be used. We analyzed the factors related to screw use with a press-fit uncemented cup and assessed whether screw use is associated with the same rates of loosening and revision as a press-fit technique. We retrospectively reviewed 248 patients who underwent THA using the same prosthetic design. Eighty-eight hips had screws to achieve primary cup fixation (Group 1), and 189 did not (Group 2). Mean age was 50 years (range, 14-73 years). We analyzed factors related to the patient, acetabular type, and reconstruction of the rotation center of the hip. Minimum followup was 5 years (mean, 8.9 years; range, 5-12 years). We found higher screw use in women, patients with less physical activity, Acetabular Types A or C, and a distance from the center of the prosthetic femoral head to the normal center of rotation of more than 3 mm. There were four revisions in Group 1 and five in Group 2. Eight hips had radiographic loosening in Group 1 and nine in Group 2. Cups with a postoperative abduction angle of more than 50° had a higher risk for loosening. Press fit was achieved less frequently in women and patients with Acetabular Types A or C and less physical activity; a closer distance to the normal center of rotation decreased screw use. Screw use to augment fixation achieved survival similar to that of a press-fit cup. Level II, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

The influence of head diameter and wall thickness on deformations of metallic acetabular press-fit cups and UHMWPE liners: a finite element analysis.

PubMed

Goebel, Paul; Kluess, Daniel; Wieding, Jan; Souffrant, Robert; Heyer, Horst; Sander, Manuela; Bader, Rainer

2013-03-01

To increase the range of motion of total hip endoprostheses, prosthetic heads need to be enlarged, which implies that the cup and/or liner thickness must decrease. This may have negative effects on the wear rate, because the acetabular cups and liners could deform during press-fit implantation and hip joint loading. We compared the metal cup and polyethylene liner deformations that occurred when different wall thicknesses were used in order to evaluate the resulting changes in the clearance of the articulating region. A parametric finite element model utilized three cup and liner wall thicknesses to analyze cup and liner deformations after press-fit implantation into the pelvic bone. The resultant hip joint force during heel strike was applied while the femur was fixed, accounting for physiological muscle forces. The deformation behavior of the liner under joint loading was therefore assessed as a function of the head diameter and the resulting clearance. Press-fit implantation showed diametral cup deformations of 0.096, 0.034, and 0.014 mm for cup wall thicknesses of 3, 5, and 7 mm, respectively. The largest deformations (average 0.084 ± 0.003 mm) of liners with thicknesses of 4, 6, and 8 mm occurred with the smallest cup wall thickness (3 mm). The smallest liner deformation (0.011 mm) was obtained with largest cup and liner wall thicknesses. Under joint loading, liner deformations in thin-walled acetabular cups (3 mm) reduced the initial clearance by about 50 %. Acetabular press-fit cups with wall thicknesses of ≤5 mm should only be used in combination with polyethylene liners >6 mm thick in order to minimize the reduction in clearance.

Sarcopenia Is Predictive of 1-Year Mortality After Acetabular Fractures in Elderly Patients.

PubMed

Mitchell, Phillip M; Collinge, Cory A; OʼNeill, David E; Bible, Jesse E; Mir, Hassan R

2018-06-01

To determine whether sarcopenia is an independent predictor of mortality in geriatric acetabular fractures. Retrospective cohort. American College of Surgeons Level I trauma center. One hundred and forty-six patients over the age 60 with acetabular fractures treated at our institution over a 12-year period. The primary outcome was 1-year mortality, collected using the Social Security Death Index. We used the psoas:lumbar vertebral index (PLVI), calculated using the cross-sectional area of the L4 vertebral body and the left and right psoas muscles, to assess for sarcopenia. Using a multivariate logistic regression model, we found that low PLVI was associated with increased 1-year mortality (P = 0.046) when controlling for age, gender, Charlson Comorbidity Index, Injury Severity Score (ISS), smoking status, and associated pelvic ring injury. Increasing age and ISS also showed a relationship with 1-year mortality in this cohort (P < 0.001, P < 0.001, respectively). We defined sarcopenia as those patients in the lowest quartile of PLVI. The mortality rate of this cohort was 32.4%, compared with 11.0% in patients without sarcopenia (odds ratio 4.04; 95% confidence interval 1.62-10.1). Age >75 years, ISS >14, and sarcopenia had 1-year mortality rates of 37.1%, 30.9%, and 32.4%, respectively. In patients with all 3 factors, the mortality rate was 90%. Sarcopenia is an independent risk factor for 1-year mortality in elderly patients with acetabular fractures. This study highlights the importance of objective measures to assess frailty in elderly patients who have sustained fractures about the hip and pelvis. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Myofascial treatment for patients with acetabular labral tears: a single-subject research design study.

PubMed

Cashman, Glenn E; Mortenson, W Ben; Gilbart, Michael K

2014-08-01

Single-subject research design using 4 consecutive patients. To assess whether treatment using soft tissue therapy (ART or Active Release Technique), stretching, and strengthening of the hip abductors, hip external rotators, and tensor fascia latae muscles reduces pain and improves self-reported hip function in patients with acetabular labral tears who also have posterolateral hip pain of suspected myofascial origin. Acetabular labral tears cause pain in some but not all patients. Pain commonly presents anteriorly but may also present posteriorly and laterally. The standard of care is arthroscopic repair, which helps many but not all patients. It is possible that these patients may present with extra-articular contributions to their pain, such as myofascial pain, making their clinical presentation more complex. No previous study has assessed soft tissue therapy as a treatment option for this subset of patients. This A-B-A design used repeated measures of the Hip Outcome Score and visual analog scale for pain. Four patients were treated for 6 to 8 weeks, using a combination of soft tissue therapy, stretching, and strengthening for the hip abductors, external rotators, and tensor fascia latae. Data were assessed visually, statistically, and by comparing mean differences before and after intervention. All 4 patients experienced both statistically significant and clinically meaningful improvement in posterolateral hip pain and hip-related function. Three patients also experienced reduction in anteromedial hip pain. Myofascial hip pain may contribute to hip-related symptoms and disability in patients with acetabular labral tears and posterolateral hip pain. These patients may benefit from soft tissue therapy combined with stretching and strengthening exercises targeting the hip abductors, tensor fascia latae, and hip external rotator muscles. Level of Evidence Therapy, level 4.

Obstacles to reduction in infantile developmental dysplasia of the hip

PubMed Central

Studer, K.; Williams, N.; Studer, P.; Baker, M.; Glynn, A.; Foster, B. K.; Cundy, P. J.

2017-01-01

Abstract Purpose Identification of anatomical structures that block ­reduction in developmental dysplasia of the hip (DDH) is ­important for the management of this challenging condition. Obstacles to reduction seen on arthrogram are well-known. However, despite the increasing use of MRI in the assessment of adequacy of reduction in DDH, the interpretation of MRI patho-anatomy is ill-defined with a lack of relevant literature to guide clinicians. Method This is a retrospective analysis of the MRI of patients with DDH treated by closed reduction over a five-year period (between 2009 and 2014). Neuromuscular and genetic disorders were excluded. Each MRI was analysed by two orthopaedic surgeons and a paediatric musculoskeletal radiologist to identify the ligamentum teres, pulvinar, transverse acetabular ligament (TAL), capsule, labrum and acetabular roof cartilage hypertrophy. Inter- and intraobserver reliability was calculated. The minimum follow-up was 12 months. Results A total of 29 patients (38 hips) underwent closed reduction for treatment of DDH. Eight hips showed persistent subluxation on post-operative MRI. Only three of these eight hips showed an abnormality on arthrogram. The pulvinar was frequently interpreted as ‘abnormal’ on MRI. The main obstacles identified on MRI were the ligamentum teres (15.8%), labrum (13.1%) and acetabular roof cartilage hypertrophy (13.2%). The inter-rater reliability was good for TAL, capsule and pulvinar; moderate for ligamentum teres and labrum; and poor for hypertrophied cartilage. Conclusion The labrum, ligamentum teres and acetabular roof cartilage hypertrophy are the most important structures seen on MRI preventing complete reduction of DDH. Focused interpretation of these structures may assist in the management of DDH. PMID:29081850

Biomechanical analysis using FEA and experiments of a standard plate method versus three cable methods for fixing acetabular fractures with simultaneous THA.

PubMed

Aziz, Mina S R; Dessouki, Omar; Samiezadeh, Saeid; Bougherara, Habiba; Schemitsch, Emil H; Zdero, Radovan

2017-08-01

Acetabular fractures potentially account for up to half of all pelvic fractures, while pelvic fractures potentially account for over one-tenth of all human bone fractures. This is the first biomechanical study to assess acetabular fracture fixation using plates versus cables in the presence of a total hip arthroplasty, as done for the elderly. In Phase 1, finite element (FE) models compared a standard plate method versus 3 cable methods for repairing an acetabular fracture (type: anterior column plus posterior hemi-transverse) subjected to a physiological-type compressive load of 2207N representing 3 x body weight for a 75kg person during walking. FE stress maps were compared to choose the most mechanically stable cable method, i.e. lowest peak bone stress. In Phase 2, mechanical tests were then done in artificial hemipelvises to compare the standard plate method versus the optimal cable method selected from Phase 1. FE analysis results showed peak bone stresses of 255MPa (Plate method), 205MPa (Mears cable method), 250MPa (Kang cable method), and 181MPa (Mouhsine cable method). Mechanical tests then showed that the Plate method versus the Mouhsine cable method selected from Phase 1 had higher stiffness (662versus 385N/mm, p=0.001), strength (3210versus 2060N, p=0.009), and failure energy (8.8versus 6.2J, p=0.002), whilst they were statistically equivalent for interfragmentary sliding (p≥0.179) and interfragmentary gapping (p≥0.08). The Plate method had superior mechanical properties, but the Mouhsine cable method may be a reasonable alternative if osteoporosis prevents good screw thread interdigitation during plating. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Computed tomography arthrography with traction in the human hip for three-dimensional reconstruction of cartilage and the acetabular labrum

PubMed Central

Henak, C.R.; Abraham, C.L.; Peters, C.L.; Sanders, R.K.; Weiss, J.A.; Anderson, A.E.

2014-01-01

AIM To develop and demonstrate the efficacy of a computed tomography arthrography (CTA) protocol for the hip that enables accurate three-dimensional reconstructions of cartilage and excellent visualization of the acetabular labrum. MATERIALS AND METHODS Ninety-three subjects were imaged (104 scans); 68 subjects with abnormal anatomy, 11 patients after periacetabular osteotomy surgery, and 25 subjects with normal anatomy. Fifteen to 25 ml of contrast agent diluted with lidocaine was injected using a lateral oblique approach. A Hare traction splint applied traction during CT. The association between traction force and intra-articular joint space was assessed qualitatively under fluoroscopy. Cartilage geometry was reconstructed from the CTA images for 30 subjects; the maximum joint space under traction was measured. RESULTS Using the Hare traction splint, the intra-articular space and boundaries of cartilage could be clearly delineated throughout the joint; the acetabular labrum was also visible. Dysplastic hips required less traction (~5 kg) than normal and retroverted hips required (>10 kg) to separate the cartilage. An increase in traction force produced a corresponding widening of the intra-articular joint space. Under traction, the maximum width of the intra-articular joint space during CT ranged from 0.98–6.7 mm (2.46 ± 1.16 mm). CONCLUSIONS When applied to subjects with normal and abnormal hip anatomy, the CTA protocol presented yields clear delineation of the cartilage and the acetabular labrum. Use of a Hare traction splint provides a simple, cost-effective method to widen the intra-articular joint space during CT, and provides flexibility to vary the traction as required. PMID:25070373

The obturator oblique and iliac oblique/outlet views predict most accurately the adequate position of an anterior column acetabular screw.

PubMed

Guimarães, João Antonio Matheus; Martin, Murphy P; da Silva, Flávio Ribeiro; Duarte, Maria Eugenia Leite; Cavalcanti, Amanda Dos Santos; Machado, Jamila Alessandra Perini; Mauffrey, Cyril; Rojas, David

2018-06-08

Percutaneous fixation of the acetabulum is a treatment option for select acetabular fractures. Intra-operative fluoroscopy is required, and despite various described imaging strategies, it is debatable as to which combination of fluoroscopic views provides the most accurate and reliable assessment of screw position. Using five synthetic pelvic models, an experimental setup was created in which the anterior acetabular columns were instrumented with screws in five distinct trajectories. Five fluoroscopic images were obtained of each model (Pelvic Inlet, Obturator Oblique, Iliac Oblique, Obturator Oblique/Outlet, and Iliac Oblique/Outlet). The images were presented to 32 pelvic and acetabular orthopaedic surgeons, who were asked to draw two conclusions regarding screw position: (1) whether the screw was intra-articular and (2) whether the screw was intraosseous in its distal course through the bony corridor. In the assessment of screw position relative to the hip joint, accuracy of surgeon's response ranged from 52% (iliac oblique/outlet) to 88% (obturator oblique), with surgeon confidence in the interpretation ranging from 60% (pelvic inlet) to 93% (obturator oblique) (P < 0.0001). In the assessment of intraosseous position of the screw, accuracy of surgeon's response ranged from 40% (obturator oblique/outlet) to 79% (iliac oblique/outlet), with surgeon confidence in the interpretation ranging from 66% (iliac oblique) to 88% (pelvic inlet) (P < 0.0001). The obturator oblique and obturator oblique/outlet views afforded the most accurate and reliable assessment of penetration into the hip joint, and intraosseous position of the screw was most accurately assessed with pelvic inlet and iliac oblique/outlet views. Clinical Question.

Emerging technologies in arthroplasty: additive manufacturing.

PubMed

Banerjee, Samik; Kulesha, Gene; Kester, Mark; Mont, Michael A

2014-06-01

Additive manufacturing is an industrial technology whereby three-dimensional visual computer models are fabricated into physical components by selectively curing, depositing, or consolidating various materials in consecutive layers. Although initially developed for production of simulated models, the technology has undergone vast improvements and is currently increasingly being used for the production of end-use components in various aerospace, automotive, and biomedical specialties. The ability of this technology to be used for the manufacture of solid-mesh-foam monolithic and coated components of complex geometries previously considered unmanufacturable has attracted the attention of implant manufacturers, bioengineers, and orthopedic surgeons. Currently, there is a paucity of reports describing this fabrication method in the orthopedic literature. Therefore, we aimed to briefly describe this technology, some of the applications in other orthopedic subspecialties, its present use in hip and knee arthroplasty, and concerns with the present form of the technology. As there are few reports of clinical trials presently available, the true benefits of this technology can only be realized when studies evaluating the clinical and radiographic outcomes of cementless implants manufactured with additive manufacturing report durable fixation, less stress shielding, and better implant survivorship. Nevertheless, the authors believe that this technology holds great promise and may potentially change the conventional methods of casting, machining, and tooling for implant manufacturing in the future. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Basic Science Considerations in Primary Total Hip Replacement Arthroplasty

PubMed Central

Mirza, Saqeb B; Dunlop, Douglas G; Panesar, Sukhmeet S; Naqvi, Syed G; Gangoo, Shafat; Salih, Saif

2010-01-01

Total Hip Replacement is one of the most common operations performed in the developed world today. An increasingly ageing population means that the numbers of people undergoing this operation is set to rise. There are a numerous number of prosthesis on the market and it is often difficult to choose between them. It is therefore necessary to have a good understanding of the basic scientific principles in Total Hip Replacement and the evidence base underpinning them. This paper reviews the relevant anatomical and biomechanical principles in THA. It goes on to elaborate on the structural properties of materials used in modern implants and looks at the evidence base for different types of fixation including cemented and uncemented components. Modern bearing surfaces are discussed in addition to the scientific basis of various surface engineering modifications in THA prostheses. The basic science considerations in component alignment and abductor tension are also discussed. A brief discussion on modular and custom designs of THR is also included. This article reviews basic science concepts and the rationale underpinning the use of the femoral and acetabular component in total hip replacement. PMID:20582240

Prevention of longitudinal crack propagation around a femoral prosthesis: a study of cerclage wire fixation.

PubMed

Difazio, F A; Incavo, S J; Howe, J D

1993-09-01

This study examined the effect of single versus triple-wrap cerclage fixation techniques in preventing propagation of a longitudinal fracture around a cementless femoral prosthesis. A proximal filling femoral component was implanted in 14 matched pairs of fresh-frozen bovine femora, following placement of a 45-mm longitudinal crack in the anteromedial cortical wall of the proximal femur. In one group of seven pairs, a single cerclage wire was applied to one specimen of each pair. A triple-wrap of a single cerclage wire was similarly placed in one specimen of each of the other seven pairs. All specimens were axially loaded on a materials testing system machine and the force required to propagate the fracture of the proximal femur was recorded. A triple-wrap cerclage technique required a significant increase in the force to propagate a proximal femur fracture around a non-cemented prosthesis when compared to a single cerclage wire. Copyright © 1993. Published by Elsevier Ltd.

Gender Differences in Hip Anatomy: Possible Implications for Injury Tolerance in Frontal Collisions

PubMed Central

Wang, Stewart C.; Brede, Chris; Lange, David; Poster, Craig S.; Lange, Aaron W.; Kohoyda-Inglis, Carla; Sochor, Mark R.; Ipaktchi, Kyros; Rowe, Stephen A.; Patel, Smita; Garton, Hugh J.

2004-01-01

Male occupants in frontal motor vehicle collisions have reduced tolerance for hip fractures than females in similar crashes. We studied 92 adult pelvic CT scans and found significant gender differences in bony pelvic geometry, including acetabular socket depth and femoral head width. Significant differences were also noted in the presentation angle of the acetabular socket to frontal loading. The observed differences provide biomechanical insight into why hip injury tolerance may differ with gender. These findings have implications for the future design of vehicle countermeasures as well as finite element models capable of more accurately predicting body tolerances to injury. PMID:15319131

Hemodynamic Deterioration in Lateral Compression Pelvic Fracture After Prehospital Pelvic Circumferential Compression Device Application.

PubMed

Garner, Alan A; Hsu, Jeremy; McShane, Anne; Sroor, Adam

Increased fracture displacement has previously been described with the application of pelvic circumferential compression devices (PCCDs) in patients with lateral compression-type pelvic fracture. We describe the first reported case of hemodynamic deterioration temporally associated with the prehospital application of a PCCD in a patient with a complex acetabular fracture with medial displacement of the femoral head. Active hemorrhage from a site adjacent to the acetabular fracture was subsequently demonstrated on angiography. Caution in the application of PCCDs to patients with lateral compression-type fractures is warranted. Copyright © 2017 Air Medical Journal Associates. All rights reserved.

The ligaments of the canine hip joint revisited.

PubMed

Casteleyn, C; den Ouden, I; Coopman, F; Verhoeven, G; Van Cruchten, S; Van Ginneken, C; Van Ryssen, B; Simoens, P

2015-12-01

Numerous conventional anatomical textbooks describe the canine hip joint, but many contradictions, in particular regarding the ligament of the femoral head, are present. This paper presents a brief overview of the different literature descriptions. These are compared with own observations that have resulted in a revised description of the anatomy of the ligament of the femoral head in the dog. To this purpose, the hip joints of 41 dogs, euthanized for reasons not related to this study and devoid of lesions related to hip joint pathology, were examined. It was observed that the ligament of the femoral head is not a single structure that attaches only to the acetabular fossa, as generally accepted, but it also connects to the transverse acetabular ligament and is complemented by a strong accessory ligament that courses in caudal direction to attach in the elongation of the acetabular notch that extends on the cranioventral surface of the body of the ischium. The description of this accessory ligament in conventional anatomical handbooks is incomplete. This description of the accessory ligament of the femoral head could support the research unravelling the etiopathogenesis of hip instability. © 2014 Blackwell Verlag GmbH.

Micro X-Ray Computed Tomography Mass Loss Assessment of Different UHMWPE: A Hip Joint Simulator Study on Standard vs. Cross-Linked Polyethylene

PubMed Central

Zanini, Filippo; Carmignato, Simone

2017-01-01

More than 60.000 hip arthroplasty are performed every year in Italy. Although Ultra-High-Molecular-Weight-Polyethylene remains the most used material as acetabular cup, wear of this material induces over time in vivo a foreign-body response and consequently osteolysis, pain, and the need of implant revision. Furthermore, oxidative wear of the polyethylene provoke several and severe failures. To solve these problems, highly cross-linked polyethylene and Vitamin-E-stabilized polyethylene were introduced in the last years. In in vitro experiments, various efforts have been made to compare the wear behavior of standard PE and vitamin-E infused liners. In this study we compared the in vitro wear behavior of two different configurations of cross-linked polyethylene (with and without the add of Vitamin E) vs. the standard polyethylene acetabular cups. The aim of the present study was to validate a micro X-ray computed tomography technique to assess the wear of different commercially available, polyethylene’s acetabular cups after wear simulation; in particular, the gravimetric method was used to provide reference wear values. The agreement between the two methods is documented in this paper. PMID:28107468

REHABILITATION AFTER HIP ARTHROSCOPY AND LABRAL REPAIR IN A HIGH SCHOOL FOOTBALL ATHLETE

PubMed Central

Kolber, Morey J.

2012-01-01

Study Design: Case Report Background: Femoral acetabular impingement (FAI) has been implicated in the etiology of acetabular labral tears. The rehabilitation of younger athletes following arthroscopic surgery for FAI and labral tears is often complex and multifactorial. A paucity of evidence exists to describe the rehabilitation of younger athletes who have undergone arthroscopic hip surgery. Case Presentation: This case report describes a four-phase rehabilitation program for a high school football player who underwent hip arthroscopy with a labral repair and chondroplasty. Outcomes: The player returned to training for football 16 weeks later and at the 4 month follow-up was pain free with no signs of FAI. Discussion: There is little evidence regarding the rehabilitation of younger athletes who undergo arthroscopic hip surgery. This case study described a four phase rehabilitation program for a high school football player who underwent hip arthroscopy and labral repair. The patient achieved positive outcomes with a full return to athletic activity and football. The overall success of these patients depends on the appropriate surgical procedure and rehabilitation program. Key Words: Femoral acetabular impingement (FAI), hip, hip impingement Level of evidence: 4-Case report PMID:22530192

Biocompatibility of Bespoke 3D-Printed Titanium Alloy Plates for Treating Acetabular Fractures.

PubMed

Lin, Xuezhi; Xiao, Xingling; Wang, Yimeng; Gu, Cheng; Wang, Canbin; Chen, Jiahui; Liu, Han; Luo, Juan; Li, Tao; Wang, Di; Fan, Shicai

2018-01-01

Treatment of acetabular fractures is challenging, not only because of its complicated anatomy but also because of the lack of fitting plates. Personalized titanium alloy plates can be fabricated by selective laser melting (SLM) but the biocompatibility of these three-dimensional printing (3D-printed) plates remains unknown. Plates were manufactured by SLM and their cytocompatibility was assessed by observing the metabolism of L929 fibroblasts incubated with culture medium extracts using a CCK-8 assay and their morphology by light microscopy. Allergenicity was tested using a guinea pig maximization test. In addition, acute systemic toxicity of the 3D-printed plates was determined by injecting extracts from the implants into the tail veins of mice. Finally, the histocompatibility of the plates was investigated by implanting them into the dorsal muscles of rabbits. The in vitro results suggested that cytocompatibility of the 3D-printed plates was similar to that of conventional plates. The in vivo data also demonstrated histocompatibility that was comparable between the two manufacturing techniques. In conclusion, both in vivo and in vitro experiments suggested favorable biocompatibility of 3D-printed titanium alloy plates, indicating that it is a promising option for treatment of acetabular fractures.

Biocompatibility of Bespoke 3D-Printed Titanium Alloy Plates for Treating Acetabular Fractures

PubMed Central

Xiao, Xingling; Wang, Yimeng; Gu, Cheng; Wang, Canbin; Chen, Jiahui; Liu, Han; Luo, Juan; Li, Tao

2018-01-01

Treatment of acetabular fractures is challenging, not only because of its complicated anatomy but also because of the lack of fitting plates. Personalized titanium alloy plates can be fabricated by selective laser melting (SLM) but the biocompatibility of these three-dimensional printing (3D-printed) plates remains unknown. Plates were manufactured by SLM and their cytocompatibility was assessed by observing the metabolism of L929 fibroblasts incubated with culture medium extracts using a CCK-8 assay and their morphology by light microscopy. Allergenicity was tested using a guinea pig maximization test. In addition, acute systemic toxicity of the 3D-printed plates was determined by injecting extracts from the implants into the tail veins of mice. Finally, the histocompatibility of the plates was investigated by implanting them into the dorsal muscles of rabbits. The in vitro results suggested that cytocompatibility of the 3D-printed plates was similar to that of conventional plates. The in vivo data also demonstrated histocompatibility that was comparable between the two manufacturing techniques. In conclusion, both in vivo and in vitro experiments suggested favorable biocompatibility of 3D-printed titanium alloy plates, indicating that it is a promising option for treatment of acetabular fractures. PMID:29682523

The epidemiology and injury patterns of acetabular fractures: are the USA and China comparable?

PubMed

Mauffrey, Cyril; Hao, Jiandong; Cuellar, Derly O; Herbert, Benoit; Chen, Xiao; Liu, Bo; Zhang, Yingze; Smith, Wade

2014-11-01

Acetabular fractures are rare injuries in heterogeneous patient groups, making it difficult to develop adequately powered prospective single-center clinical trials in the USA or Europe. Chinese trauma centers treat a high volume of these injuries, and if the patient population and injury patterns are comparable to those in the USA, this might support development of multicenter studies in Level I trauma centers in the two countries. We determined whether the following parameters were similar between operative acetabular fractures treated at Chinese and US trauma centers: (1) epidemiology of injured patients, (2) mechanism of injuries and fracture types, and (3) hospital stay parameters, including symptomatic postoperative deep vein thrombosis (DVT) rate. We extracted data from trauma databases for patients admitted with acetabular fractures managed surgically from 2005 to 2012 for one Chinese center and from 2008 to 2012 for one US center. Sex, age, mechanism of injury, fracture classification, Injury Severity Score (ISS), time from injury to surgery, length of hospital stay, and symptomatic DVT rate were analyzed. We included 661 Chinese patients (539 men, 122 women) and 212 US patients (163 men, 49 women). Mean age at time of injury was different between China and the USA, at 40 years with a unimodal distribution and 44 years with a bimodal distribution (p<0.001), respectively. Incidence of surgically treated acetabular fractures has been increasing in China but decreasing in the USA. Mean ISSs were comparable. Although the distribution of mechanisms of injury was different (p=0.004), high-energy injuries (motor vehicle accidents, falls>10 feet) still accounted for most fractures in both centers. Fracture classifications (per Letournel) were comparable, with posterior wall fractures most common. Mean time from injury to surgery and mean hospital stay were longer in China than in the USA (9 versus 3 days [p<0.001] and 26 versus 11 days [p<0.001], respectively). Symptomatic DVT rates were comparable. Although we identified differences between the two centers, we also noted important similarities. Multicenter clinical studies involving these locations should be performed with caution and focus on similar end points, taking into account the populations' baseline differences. Because of the potential for such differences, this kind of validation study should be performed before embarking on resource-intensive multicenter trials. Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

The effect of variable size posterior wall acetabular fractures on contact characteristics of the hip joint.

PubMed

Olson, S A; Bay, B K; Pollak, A N; Sharkey, N A; Lee, T

1996-01-01

The indications for open reduction and internal fixation of posterior wall acetabular fractures associated with a clinically stable hip joint are unclear. In previous work a large posterior wall defect (27% articular surface area) resulted in significant alteration of load transmission across the hip; specifically, there was a transition from evenly distributed loading along the acetabular articular surface to loading concentrated mainly in the superior portion of the articular surface during simulated single leg stance. However, the majority of posterior wall fractures involve a smaller amount of the articular surface. Posterior wall acetabular fractures not associated with instability of the hip are commonly treated nonoperatively. This practice does not account for the size of the posterior wall fracture. To study the biomechanical consequences of variably sized articular defects, a laboratory experiment was conducted evaluating three progressively larger posterior wall defects of the acetabulum during simulated single leg stance using superlow Fuji prescale film (Itochu International, New York): (a) 1/3 articular surface width through a 50 degrees arc along the posterior wall of the acetabulum, (b) 2/3, and (c) 3/3 articular width defects through the same 50 degrees arc along the posterior wall of the acetabulum. In the intact acetabulum, 48% of the total articular contact was located in the superior acetabulum. Twenty-eight percent of articular contact was in the anterior wall region of the acetabulum and 24% in the posterior wall region. After the 1/3 width posterior wall defect, 64% of the articular contact was located in the superior acetabulum (p = 0.0011). The 2/3 width posterior wall defect resulted in 71% of articular contact area being located in the superior acetabulum (p = 0.0006). After the 3/3 width posterior wall defect, 77% of articular contact was located in the superior acetabulum, significantly greater than the intact condition (p < 0.0001) and 1/3 width defect (p = 0.0222). The total absolute contact areas for all defect conditions were significantly less than the intact conditions. The results of this study reconfirm the observation that posterior wall fractures of the acetabulum significantly alter the articular contact characteristics in the hip during single leg stance. The relationship between defect size and changes in joint contact showed that the smallest defect resulted in the greatest alteration in joint contact areas, whereas larger defects resulted in minor increments of change in contact area. This finding is of concern because the clinical practice of managing acetabular fractures nonoperatively if the hip joint is stable is based on the supposition that the joint retains enough integrity to function without undue risk of late posttraumatic osteoarthritis. A better understanding of the natural history of stable posterior wall acetabular fractures is needed to ascertain whether some of these fractures merit operative repair.

What Is the Early/Mid-term Survivorship and Functional Outcome After Bernese Periacetabular Osteotomy in a Pediatric Surgeon Practice?

PubMed

Grammatopoulos, George; Wales, Jeremy; Kothari, Alpesh; Gill, Harinderjit S; Wainwright, Andrew; Theologis, Tim

2016-05-01

The Bernese periacetabular osteotomy (PAO) is a recognized joint-preserving procedure. Achieving joint stability without creating impingement is important, but the orientation target that best balances these sometimes competing goals has not yet been clearly defined. Moreover, the learning curve of this challenging procedure has not been described. The purposes of this study were (1) to determine the 10-year survivorship and functional outcome after Bernese PAO in a single-surgeon series; (2) to review which patient, surgical, and radiographic factors might predict outcome after the procedure; and (3) to define the learning curve for target acetabular correction. The first 68 PAOs performed for symptomatic hip dysplasia were retrospectively evaluated. None have been lost to followup with followup less than 2 years. Endpoints for the lost to followup (n = 2) are at the time of when last seen. During the study period, the same surgeon performed 562 pelvic osteotomies (including Salter, Pemberton, Dega and Chiari) and 64 shelf acetabuloplasties. Bernese PAO was used only for symptomatic dysplasia (center-edge angle < 25° and nonhorizontal acetabular roof) in developmentally mature hips without evidence of major joint incongruence or subluxation. Most patients were female (n = 49 [60 hips, 88%]); mean age at operation was 25 years (SD 7). Sixteen hips had previous hip procedures. The study's mean followup was 8 years (range, 2-18 years). Patient-reported functional outcome was obtained using the WOMAC score (best-worst: 0-96). Radiographic parameters of dysplasia (acetabular index [AI], center-edge angle [CEA], congruency, Tönnis grade, and joint space) were evaluated from preoperative and postoperative radiographs using computer software. The 10-year survival rate was 93% (95% confidence interval [CI], 82%-100%); four patients underwent further surgery to the hip in the study period. The mean WOMAC was 12 (range, 0-54). Factors that influenced survival included joint congruency (100% versus 78%; 95% CI, 61%-96%; p = 0.03) and acetabular orientation correction achieved (AIpostoperative < 15° [100% versus 65%; 95% CI, 43-88; p < 0.001] and CEApostoperative 20° to 40° [100% versus 71.9%; 52.8-100; p < 0.001]). Better WOMAC scores were seen if postoperative AI < 15° (7 versus 25, p = 0.005) and CEA between 20° and 40° (7 versus 23, p = 0.005) were achieved. The chances of obtaining acetabular correction within this range improved after the 20(th) procedure (30% versus 70%, p = 0.008). This study reports excellent results after Bernese PAO in the hands of an experienced pediatric hip surgeon. We advocate cautious correction of the acetabular fragment. Future studies should concentrate on how to determine what the optimal target is and how to achieve it intraoperatively, minimizing the learning curve associated with it. Level III, therapeutic study.

Early radiological and functional outcomes for a cementless press-fit design modular femoral stem revision system.

PubMed

Hancock, Douglas S; Sharplin, Paul K; Larsen, Peter D; Phillips, Fredrick Ts

2018-05-01

To assess early radiological and functional outcomes of revision hip surgery with a cementless press-fit design femoral stem. A retrospective review of 48 consecutive revision total hip replacements using the RECLAIM revision hip system, between October 2012 and August 2015. Radiographic assessment was undertaken with serial anteroposterior (AP) X-rays of the pelvis. Risk factors for subsidence were evaluated. Prospective clinical follow up was performed on 21 patients to assess functional outcomes. Mean stem subsidence was 1.1 mm (95% confidence interval[CI]: 0.63-1.57). Median follow up of 12 months. An inverse relationship was observed between level of subsidence and femoral stem diameter r = -0.45, p = 0.001. Subsidence at the time of follow-up assessment was correlated with initial subsidence (correlation coefficient rho 0.69, p = 0.001). The mean Merle d'Aubigne score at the latest follow up was 14.2 (range 8-17). The mean OHS was 34.1 (range 15-48). Early radiological and functional outcomes for the RECLAIM revision system showed very low levels of subsidence and good functional outcomes. There was an association with smaller diameter femoral stems and greater levels of subsidence.

Fabrication of low-cost, cementless femoral stem 316L stainless steel using investment casting technique.

PubMed

Baharuddin, Mohd Yusof; Salleh, Sh-Hussain; Suhasril, Andril Arafat; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Omar, Mohd Afian; Abd Kader, Ab Saman; Mohd Noor, Alias; A Harris, Arief Ruhullah; Abdul Majid, Norazman

2014-07-01

Total hip arthroplasty is a flourishing orthopedic surgery, generating billions of dollars of revenue. The cost associated with the fabrication of implants has been increasing year by year, and this phenomenon has burdened the patient with extra charges. Consequently, this study will focus on designing an accurate implant via implementing the reverse engineering of three-dimensional morphological study based on a particular population. By using finite element analysis, this study will assist to predict the outcome and could become a useful tool for preclinical testing of newly designed implants. A prototype is then fabricated using 316L stainless steel by applying investment casting techniques that reduce manufacturing cost without jeopardizing implant quality. The finite element analysis showed that the maximum von Mises stress was 66.88 MPa proximally with a safety factor of 2.39 against endosteal fracture, and micromotion was 4.73 μm, which promotes osseointegration. This method offers a fabrication process of cementless femoral stems with lower cost, subsequently helping patients, particularly those from nondeveloped countries. Copyright © 2013 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Poor short term outcome with a metal-on-metal total hip arthroplasty.

PubMed

Levy, Yadin D; Ezzet, Kace A

2013-08-01

Metal-on-metal (MoM) bearings for total hip arthroplasty (THA) have come under scrutiny with reports of high failure rates. Clinical outcome studies with several commercially available MoM THA bearings remain unreported. We evaluated 78 consecutive MoM THAs from a single manufacturer in 68 patients. Sixty-six received cobalt-chrome (CoCr) monoblock and 12 received modular titanium acetabular cups with internal CoCr liners. Femoral components were titanium with modular necks. At average 2.1 years postoperatively, 12 THAs (15.4%) demonstrated aseptic failure (10 revisions, 2 revision recommended). All revised hips demonstrated capsular necrosis with positive histology reaction for aseptic lymphocytic vasculitis-associated lesions/adverse local tissue reactions. Prosthetic instability following revision surgery was relatively common. Female gender was a strong risk factor for failure, though smaller cups were not. Both monoblock and modular components fared poorly. Corrosion was frequently observed around the proximal and distal end of the modular femoral necks. Copyright © 2013 Elsevier Inc. All rights reserved.

Intra- and extra-articular planes of reference for use in total hip arthroplasty: a preliminary study.

PubMed

Hausselle, Jerome; Moreau, Pierre Etienne; Wessely, Loic; de Thomasson, Emmanuel; Assi, Ayman; Parratte, Sebastien; Essig, Jerome; Skalli, Wafa

2012-08-01

Acetabular component malalignment in total hip arthroplasty can lead to potential complications such as dislocation, component impingement and excessive wear. Computer-assisted orthopaedic surgery systems generally use the anterior pelvic plane (APP). Our aim was to investigate the reliability of anatomical landmarks accessible during surgery and to define new potential planes of reference. Three types of palpations were performed: virtual, on dry bones and on two cadaveric specimens. Four landmarks were selected, the reproducibility of their positioning ranging from 0.9 to 2.3 mm. We then defined five planes and tested them during palpations on two cadaveric specimens. Two planes produced a mean orientation error of 5.0° [standard deviation (SD 3.3°)] and 5.6° (SD 2.7°). Even if further studies are needed to test the reliability of such planes on a larger scale in vivo during surgery, these results demonstrated the feasibility of defining a new plane of reference as an alternative to the APP.

In vivo and ex vivo measurement of polyethylene wear in total hip arthroplasty: comparison of measurements using a CT algorithm, a coordinate-measuring machine, and a micrometer.

PubMed

Goldvasser, Dov; Hansen, Viktor J; Noz, Marilyn E; Maguire, Gerald Q; Zeleznik, Michael P; Olivecrona, Henrik; Bragdon, Charles R; Weidenhielm, Lars; Malchau, Henrik

2014-06-01

Determination of the amount of wear in a polyethylene liner following total hip arthroplasty (THA) is important for both the clinical care of individual patients and the development of new types of liners. We measured in vivo wear of the polyethylene liner using computed tomography (CT) (obtained in the course of regular clinical care) and compared it to coordinate-measuring machine (CMM) readings. Also, changes in liner thickness of the same retrieved polyethylene liner were measured using a micrometer, and were compared to CT and CMM measurements. The distance between the centers of the acetabular cup and femoral head component was measured in 3D CT, using a semi-automatic analysis method. CMM readings were performed on each acetabular liner and data were analyzed using 3D computer-aided design software. Micrometer readings compared the thickest and thinnest regions of the liner. We analyzed 10 THA CTs and retrievals that met minimal requirements for CT slice thickness and explanted cup condition. RESULTS - For the 10 cups, the mean difference between the CT readings and the CMM readings was -0.09 (-0.38 to 0.20) mm. This difference was not statistically significant (p = 0.6). Between CT and micrometer, the mean difference was 0.11 (-0.33 to 0.55) mm. This difference was not statistically significant (p = 0.6). INTERPRETATION - Our results show that CT imaging is ready to be used as a tool in clinical wear measurement of polyethylene liners used in THA.

[Tribological properties of carbon fiber-reinforced plastic. Experimental and clinical results].

PubMed

Früh, H J; Ascherl, R; Hipp, E

1997-02-01

Wear of the articulating components (especially PE-UHMW) of total hip endoprostheses is the most important technical factor limiting the functional lifetime. To minimize wear debris, ceramic heads, according to ISO 6474 (Al2O3), have been used, from 1969 paired with Al2O3 and since 1975 paired with PE-UHMW. Al2O3 balls articulating with cups made from CFRP have been in clinical use since 1988. Laboratory experiments and in-vivo testing showed minimized wear debris and mild biological response to wear products using CFRP (carbon fiber reinforced plastic) instead of PE-UHMW as the cup material. The articulating surfaces of retrieved ceramic heads (Al2O3-Biolox) and cementless CFRP cups (carbon fiber reinforced plastic, Caproman) were compared using sphericity measurement techniques, scanning electron microscopy (SEM) and roughness measurements (including advanced roughness parameters Rvk or Rpk according to ISO 4287). Altogether, the first results of the clinical study showed that the combination Al2O3-ball/CFRP-cup came up to the expected lower wear rates compared with the conventional combinations. The wear rates are comparable with the combination Al2O3/Al2O3 without the material-related problems of ceramic components in all ceramic combinations.

Biomimetic Multispiked Connecting Ti-Alloy Scaffold Prototype for Entirely-Cementless Resurfacing Arthroplasty Endoprostheses-Exemplary Results of Implantation of the Ca-P Surface-Modified Scaffold Prototypes in Animal Model and Osteoblast Culture Evaluation.

PubMed

Uklejewski, Ryszard; Rogala, Piotr; Winiecki, Mariusz; Tokłowicz, Renata; Ruszkowski, Piotr; Wołuń-Cholewa, Maria

2016-06-29

We present here-designed, manufactured, and tested by our research team-the Ti-alloy prototype of the multispiked connecting scaffold (MSC-Scaffold) interfacing the components of resurfacing arthroplasty (RA) endoprostheses with bone. The spikes of the MSC-Scaffold prototype mimic the interdigitations of the articular subchondral bone, which is the natural biostructure interfacing the articular cartilage with the periarticular trabecular bone. To enhance the osteoinduction/osteointegration potential of the MSC-Scaffold, the attempts to modify its bone contacting surfaces by the process of electrochemical cathodic deposition of Ca-P was performed with further immersion of the MSC-Scaffold prototypes in SBF in order to transform the amorphous calcium-phosphate coating in hydroxyapatite-like (HA-like) coating. The pilot experimental study of biointegration of unmodified and Ca-P surface-modified MSC-Scaffold prototypes was conducted in an animal model (swine) and in osteoblast cell culture. On the basis of a microscope-histological method the biointegration was proven by the presence of trabeculae in the interspike spaces of the MSC-Scaffold prototype on longitudinal and cross-sections of bone-implant specimens. The percentage of trabeculae in the area between the spikes of specimen containing Ca-P surface modified scaffold prototype observed in microCT reconstructions of the explanted joints was visibly higher than in the case of unmodified MSC-Scaffold prototypes. Significantly higher Alkaline Phosphatase (ALP) activity and the cellular proliferation in the case of Ca-P-modified MSC-Scaffold pre-prototypes, in comparison with unmodified pre-prototypes, was found in osteoblast cell cultures. The obtained results of experimental implantation in an animal model and osteoblast cell culture evaluations of Ca-P surface-modified and non-modified biomimetic MSC-Scaffold prototypes for biomimetic entirely-cementless RA endoprostheses indicate the enhancement of the osteoinduction/osteointegration potential by the Ca-P surface modification of the Ti-alloy MSC-Scaffold prototype. Planned further research on the prototype of this biomimetic MSC-Scaffold for a new generation of RA endoprostheses is also given.

Biomimetic Multispiked Connecting Ti-Alloy Scaffold Prototype for Entirely-Cementless Resurfacing Arthroplasty Endoprostheses—Exemplary Results of Implantation of the Ca-P Surface-Modified Scaffold Prototypes in Animal Model and Osteoblast Culture Evaluation

PubMed Central

Uklejewski, Ryszard; Rogala, Piotr; Winiecki, Mariusz; Tokłowicz, Renata; Ruszkowski, Piotr; Wołuń-Cholewa, Maria

2016-01-01

We present here—designed, manufactured, and tested by our research team—the Ti-alloy prototype of the multispiked connecting scaffold (MSC-Scaffold) interfacing the components of resurfacing arthroplasty (RA) endoprostheses with bone. The spikes of the MSC-Scaffold prototype mimic the interdigitations of the articular subchondral bone, which is the natural biostructure interfacing the articular cartilage with the periarticular trabecular bone. To enhance the osteoinduction/osteointegration potential of the MSC-Scaffold, the attempts to modify its bone contacting surfaces by the process of electrochemical cathodic deposition of Ca-P was performed with further immersion of the MSC-Scaffold prototypes in SBF in order to transform the amorphous calcium-phosphate coating in hydroxyapatite-like (HA-like) coating. The pilot experimental study of biointegration of unmodified and Ca-P surface-modified MSC-Scaffold prototypes was conducted in an animal model (swine) and in osteoblast cell culture. On the basis of a microscope-histological method the biointegration was proven by the presence of trabeculae in the interspike spaces of the MSC-Scaffold prototype on longitudinal and cross-sections of bone-implant specimens. The percentage of trabeculae in the area between the spikes of specimen containing Ca-P surface modified scaffold prototype observed in microCT reconstructions of the explanted joints was visibly higher than in the case of unmodified MSC-Scaffold prototypes. Significantly higher Alkaline Phosphatase (ALP) activity and the cellular proliferation in the case of Ca-P-modified MSC-Scaffold pre-prototypes, in comparison with unmodified pre-prototypes, was found in osteoblast cell cultures. The obtained results of experimental implantation in an animal model and osteoblast cell culture evaluations of Ca-P surface-modified and non-modified biomimetic MSC-Scaffold prototypes for biomimetic entirely-cementless RA endoprostheses indicate the enhancement of the osteoinduction/osteointegration potential by the Ca-P surface modification of the Ti-alloy MSC-Scaffold prototype. Planned further research on the prototype of this biomimetic MSC-Scaffold for a new generation of RA endoprostheses is also given. PMID:28773652

Arthroscopy in 19 children with Perthes' disease. Pathologic changes of the synovium and the joint surface.

PubMed

Suzuki, S; Kasahara, Y; Seto, Y; Futami, T; Furukawa, K; Nishino, Y

1994-12-01

Arthroscopy of the hip joint was performed in 19 children with Legg-Calvé-Perthes' disease. Proliferation of the synovium was pronounced both in the acetabular fossa and over the inner wall of the capsule. Hypervascularity was seen on the acetabular labrum in every stage of the disease. Microscopically, hyperplasia of the synovial lining cells was observed, but inflammatory changes in the synovial tissue were inconspicuous in the early stage of the disease. Although hypertrophy of the endothelial cells of the vessels was seen in the late stage of the disease, it was not distinct in the initial or fragmentation stages. Joint pain improved after irrigation during arthroscopy.

G7 BiSpherical Acetabular Shell PMCF Study

ClinicalTrials.gov

2017-11-22

Rheumatoid Arthritis; Osteoarthritis; Noninflammatory Degenerative Joint Disease; Avascular Necrosis; Correction of Functional Deformity; Non-Union Fracture; Femoral Neck Fractures; Trochanteric Fractures

Early Experience with a Short, Tapered Titanium Porous Plasma Sprayed Stem with Updated Design.

PubMed

Lombardi, Adolph V; Manocchio, Antonio G; Berend, Keith R; Morris, Michael J; Adams, Joanne B

2018-06-01

Short stem femoral components in primary total hip arthroplasty (THA) have increased in popularity since the advent of minimally invasive surgical techniques. The concept of a short stem is particularly compatible with tapered designs where the goal is to offload forces proximally in the femur. The purpose of this retrospective review was to review our early experience with a short, tapered titanium femoral component with updated design features. Beginning in November 2011 through February 2012, 92 consented patients (93 hips), at a single center, were treated with primary cementless THA using a short stem, tapered femoral component (Taperloc® Complete Microplasty; Zimmer Biomet, Warsaw, Indiana) and were available for review with a minimum two-year follow-up. Mean patient age at surgery was 63.2 years and body mass index (BMI) was 30.8 kg/m2. Mean stem length used was 110.3mm (range, 95-125). Mean follow-up was 4.5 years (2-6). Harris hip scores improved from 52.5 preoperatively to 84.7 at most recent. One stem was revised the same day for periprosthetic fracture. One patient with early infection was treated with single-stage exchange followed by recurrence that was treated successfully with two-stage exchange. A non-healing wound in one patient was treated with incision and debridement. Radiographic assessment demonstrated no evidence of loosening, osteolysis, distal hypertrophy, or pedestal formation in any hip, and all components appeared well fixed and in appropriate alignment. In this series of patients treated with primary THA using a short, tapered titanium porous plasma-sprayed femoral component with updated design features, good results were achieved with a low incidence of complications and revision. No aseptic loosening or osteolysis has occurred. Radiographic assessment was excellent for all patients.

Secure Screw Placement in Management of Acetabular Fractures Using the Suprapectineal Quadrilateral Buttress Plate.

PubMed

Egli, R J; Keel, M J B; Cullmann, J L; Bastian, J D

2017-01-01

Acetabular fractures involving predominantly the anterior column associated with a disruption of the quadrilateral surface can be treated with instrumentation implementing the stabilization of the quadrilateral surface. The recently introduced suprapectineal quadrilateral buttress plate is specifically designed to prevent secondary medial subluxation of the femoral head, especially in elderly patients with reduced ability for partial weight bearing. Whereas there are guidelines available for safe screw fixation for the anterior and posterior columns, there might be a concern for intra-articular placement of screws placed through the infrapectineal part of the quadrilateral buttress plate. Within this report we analyzed retrospectively screw placement in 30 plates in postoperative CT scans using algorithms for metal artifact reduction. None of the screws of the buttress plate penetrated the hip joint. We describe the placement, length, and spatial orientation of the screws used for fracture fixation and suggest that the use of intraoperative image intensifiers with a combined inlet-obturator view of 30-45° best projects the screws and the hip joint. Preoperative knowledge of approximate screw placement and information for accurate intraoperative imaging may contribute to safe acetabular fracture fixation and may reduce operating time and limit radiation exposure to the patient and the personnel. This trial is registered with KEK-BE: 266/2014.

Accessing 3D Location of Standing Pelvis: Relative Position of Sacral Plateau and Acetabular Cavities versus Pelvis

PubMed Central

Berthonnaud, E.; Hilmi, R.; Dimnet, J.

2012-01-01

The goal of this paper is to access to pelvis position and morphology in standing posture and to determine the relative locations of their articular surfaces. This is obtained from coupling biplanar radiography and bone modeling. The technique involves different successive steps. Punctual landmarks are first reconstructed, in space, from their projected images, identified on two orthogonal standing X-rays. Geometric models, of global pelvis and articular surfaces, are determined from punctual landmarks. The global pelvis is represented as a triangle of summits: the two femoral head centers and the sacral plateau center. The two acetabular cavities are modeled as hemispheres. The anterior sacral plateau edge is represented by an hemi-ellipsis. The modeled articular surfaces are projected on each X-ray. Their optimal location is obtained when the projected contours of their models best fit real outlines identified from landmark images. Linear and angular parameters characterizing the position of global pelvis and articular surfaces are calculated from the corresponding sets of axis. Relative positions of sacral plateau, and acetabular cavities, are then calculated. Two hundred standing pelvis, of subjects and scoliotic patients, have been studied. Examples are presented. They focus upon pelvis orientations, relative positions of articular surfaces, and pelvis asymmetries. PMID:22567279

Quantification of Wear and Deformation in Different Configurations of Polyethylene Acetabular Cups Using Micro X-ray Computed Tomography

PubMed Central

Affatato, Saverio; Zanini, Filippo; Carmignato, Simone

2017-01-01

Wear is currently quantified as mass loss of the bearing materials measured using gravimetric methods. However, this method does not provide other information, such as volumetric loss or surface deviation. In this work, we validated a technique to quantify polyethylene wear in three different batches of ultrahigh-molecular-polyethylene acetabular cups used for hip implants using nondestructive microcomputed tomography. Three different configurations of polyethylene acetabular cups, previously tested under the ISO 14242 parameters, were tested on a hip simulator for an additional 2 million cycles using a modified ISO 14242 load waveform. In this context, a new approach was proposed in order to simulate, on a hip joint simulator, high-demand activities. In addition, the effects of these activities were analyzed in terms of wear and deformations of those polyethylenes by means of gravimetric method and micro X-ray computed tomography. In particular, while the gravimetric method was used for weight loss assessment, microcomputed tomography allowed for acquisition of additional quantitative information about the evolution of local wear and deformation through three-dimensional surface deviation maps for the entire cups’ surface. Experimental results showed that the wear and deformation behavior of these materials change according to different mechanical simulations. PMID:28772616

Initial stability of a highly porous titanium cup in an acetabular bone defect model.

PubMed

Yoshimoto, Kensei; Nakashima, Yasuharu; Wakiyama, Miyo; Hara, Daisuke; Nakamura, Akihiro; Iwamoto, Mikio

2018-04-12

The purpose of this study was to quantify the initial stability of a highly porous titanium cup using an acetabular bone defect model. The maximum torque of a highly porous titanium cup, with a pore size of 640 μm and porosity of 60%, was measured using rotational and lever-out torque testing and compared to that of a titanium-sprayed cup. The bone models were prepared using a polyurethane foam block and had three levels of bone coverage: 100, 70, and 50%. The highly porous titanium cup demonstrated significantly higher maximum torque than the titanium-sprayed cups in the three levels of bone defects. On rotational torque testing, it was found to be 1.5, 1.3, and 1.3 times stronger than the titanium-sprayed cups with 100, 70 and 50% bone coverage, respectively. Furthermore, it was found to be 2.2, 2.3, and 1.5 times stronger on lever-out testing than the titanium-sprayed cup. No breakage in the porous layers was noted during the testing. This study provides additional evidence of the initial stability of highly porous titanium cup, even in the presence of acetabular bone defects. Copyright © 2018. Published by Elsevier B.V.

Comparison of the diagnostic value of ultrasonography and standing radiography for pelvic-femoral disorders in horses.

PubMed

Geburek, Florian; Rötting, Anna K; Stadler, Peter M

2009-04-01

To assess agreement between ultrasonography (transcutaneous and transrectal) and standing radiography in horses with fractures in the pelvic region and disorders of the coxofemoral joint. Case series. Warmblood horses (n=23) and 2 ponies. Medical records (1999-2008) of equids with pelvic or coxofemoral disorders that had pelvic radiography and ultrasonography were retrieved and results of both techniques compared. Radiography and ultrasonography each identified equal numbers of fractures of the tuber coxa (n=4), ilial shaft (2), ischium (3), femoral neck (2), and osteoarthritis/osis of the coxofemoral joint (6). Fractures of the ilial wing (4) were only identified by ultrasonography not by standing radiography. Of 9 acetabular fractures, 3 were identified on radiographs only, 5 were identified with both modalities. One pubic fracture was identified using ultrasonography and radiography. One acetabular and 1 pubic fracture were only diagnosed on necropsy. We found reasonable agreement (73%; 24/33) between ultrasonography and standing radiography for diagnosis of pelvic-femoral disorders. Ultrasonography was more useful for ilial wing fractures and radiography for acetabular fractures. Ultrasonography is a rapid, safe imaging technique for detecting disorders of the pelvic region with a high diagnostic yield and is a preferred initial approach in horses with severe hindlimb lameness.

Preparation of the femoral bone cavity in cementless stems: broaching versus compaction

PubMed Central

Hjorth, Mette H; Stilling, Maiken; Søballe, Kjeld; Nielsen, Poul Torben; Christensen, Poul H; Kold, Søren

2016-01-01

Background and purpose — Short-term experimental studies have confirmed that there is superior fixation of cementless implants inserted with compaction compared to broaching of the cancellous bone. Patients and methods — 1-stage, bilateral primary THA was performed in 28 patients between May 2001 and September 2007. The patients were randomized to femoral bone preparation with broaching on 1 side and compaction on the other side. 8 patients declined to attend the postoperative follow-up, leaving 20 patients (13 male) with a mean age of 58 (36–70) years for evaluation. The patients were followed with radiostereometric analysis (RSA) at baseline, at 6 and 12 weeks, and at 1, 2, and 5 years, and measurements of periprosthetic bone mineral density (BMD) at baseline and at 1, 2, and 5 years. The subjective part of the Harris hip score (HHS) and details of complications throughout the observation period were obtained at a mean interval of 6.3 (3.0–9.5) years after surgery. Results — Femoral stems in the compaction group had a higher degree of medio-lateral migration (0.21 mm, 95% CI: 0.03–0.40) than femoral stems in the broaching group at 5 years (p = 0.02). No other significant differences in translations or rotations were found between the 2 surgical techniques at 2 years (p > 0.4) and 5 years (p > 0.7) postoperatively. There were no individual stems with continuous migration. Periprosthetic BMD in the 7 Gruen zones was similar at 2 years and at 5 years. Intraoperative femoral fractures occurred in 2 of 20 compacted hips, but there were none in the 20 broached hips. The HHS and dislocations were similar in the 2 groups at 6.3 (3.0–9.5) years after surgery. Interpretation — Bone compaction as a surgical technique with the Bi-Metric stem did not show the superior outcomes expected compared to conventional broaching. Furthermore, 2 periprosthetic fractures occurred using the compaction technique, so we cannot recommend compaction for insertion of the cementless Bi-Metric stem. PMID:27759486

Total hip arthroplasty performed in patients with residual poliomyelitis: does it work?

PubMed

Yoon, Byung-Ho; Lee, Young-Kyun; Yoo, Jeong Joon; Kim, Hee Joong; Koo, Kyung-Hoi

2014-03-01

Patients with residual poliomyelitis can have advanced degenerative arthritis of the hip in the paralytic limb or the nonparalytic contralateral limb. Although THA is a treatment option for some of these patients, there are few studies regarding THA in this patient population. We therefore reviewed a group of patients with residual poliomyelitis who underwent cementless THA on either their paralytic limb or nonparalytic limb to assess (1) Harris hip scores, (2) radiographic results, including implant loosening, (3) complications, including dislocation, and (4) limb length discrepancy after recovery from surgery. From January 2000 to December 2009, 10 patients with residual poliomyelitis (10 hips, four paralytic limbs and six nonparalytic contralateral limbs) underwent THA using cementless prostheses. Harris hip scores, complications, and leg length discrepancy were determined by chart review, and confirmed by questionnaire and examination; radiographs were reviewed by two observers for this study. Followup was available for all 10 patients at a minimum of 3 years (median, 7 years; range, 3.4-13 years). Surgery was done at the same side of the paralytic limb in four hips and contralateral to the paralytic limb in six. All patients had pain relief and improvement in function; the Harris hip score improved from mean of 68 preoperatively to 92 at last followup (p = 0.043). However, only three patients had complete pain relief. One hip dislocated, which was treated successfully with closed reduction and a hip spica cast for 2 months. There was no loosening or osteolysis in this series. Leg length discrepancy improved after the index operation, but only in the THAs performed in the paralytic limbs. Cementless THA may be suitable for painful hips in adult patients with residual poliomyelitis. Nonetheless, these patients should be informed of the possibility of mild residual pain and persistent leg length discrepancy, particularly patients whose THA is performed on the limb that was not affected by polio (ie, the nonparalytic contralateral limb). Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

[Correlation analysis between residual displacement and hip function after reconstruction of acetabular fractures].

PubMed

Ma, Kunlong; Fang, Yue; Luan, Fujun; Tu, Chongqi; Yang, Tianfu

2012-03-01

To investigate the relationships between residual displacement of weight-bearing and non weight-bearing zones (gap displacement and step displacement) and hip function by analyzing the CT images after reconstruction of acetabular fractures. The CT measures and clinical outcome were retrospectively analyzed from 48 patients with displaced acetabular fracture between June 2004 and June 2009. All patients were treated by open reduction and internal fixation, and were followed up 24 to 72 months (mean, 36 months); all fractures healed after operation. The residual displacement involved the weight-bearing zone in 30 cases (weight-bearing group), and involved the non weight-bearing zone in 18 cases (non weight-bearing group). The clinical outcomes were evaluated by Merle d'Aubigné-Postel criteria, and the reduction of articular surface by CT images, including the maximums of two indexes (gap displacement and step displacement). All the data were analyzed in accordance with the Spearman rank correlation coefficient analysis. There was strong negative correlation between the hip function and the residual displacement values in weight-bearing group (r(s) = -0.722, P = 0.001). But there was no correlation between the hip function and the residual displacement values in non weight-bearing group (r(s) = 0.481, P = 0.059). The results of clinical follow-up were similar to the correlation analysis results. In weight-bearing group, the hip function had strong negative correlation with step displacement (r(s) = 0.825, P = 0.002), but it had no correlation with gap displacement (r(s) = 0.577, P = 0.134). In patients with acetabular fracture, the hip function has correlation not only with the extent of the residual displacement but also with the location of the residual displacement, so the residual displacement of weight-bearing zone is a key factor to affect the hip function. In patients with residual displacement in weight-bearing zone, the bigger the step displacement is, the worse the hip function is.

Numerical simulation of artificial hip joint motion based on human age factor

NASA Astrophysics Data System (ADS)

Ramdhani, Safarudin; Saputra, Eko; Jamari, J.

2018-05-01

Artificial hip joint is a prosthesis (synthetic body part) which usually consists of two or more components. Replacement of the hip joint due to the occurrence of arthritis, ordinarily patients aged or older. Numerical simulation models are used to observe the range of motion in the artificial hip joint, the range of motion of joints used as the basis of human age. Finite- element analysis (FEA) is used to calculate stress von mises in motion and observes a probability of prosthetic impingement. FEA uses a three-dimensional nonlinear model and considers the position variation of acetabular liner cups. The result of numerical simulation shows that FEA method can be used to analyze the performance calculation of the artificial hip joint at this time more accurate than conventional method.

"Tripolar" hip arthroplasty for failed hip resurfacing: nineteen years follow-up.

PubMed

Scheerlinck, T; Casteleyn, P P

2001-10-01

The authors describe the case of a 37-year-old patient who sustained a subcapital femoral neck fracture six months after ICLH double-cup hip resurfacing. As the polyethylene acetabular resurfacing component was undamaged and well fixed, a standard femoral stem with a bipolar head was inserted. The outer diameter of the bipolar head was chosen to fit the resurfacing socket. The "tripolar" hip arthroplasty has functioned well for 19 years and was revised for aseptic cup loosening. The cemented femoral stem was still well fixed and was not revised. Although the "tripolar" hip has functioned well in our case, we believe it is not indicated for metal on metal bearings. In this case the use of an appropriate modular head with a correct head-socket clearance is preferred.

Characterization of ossification of the posterior rim of acetabulum in the developing hip and its impact on the assessment of femoroacetabular impingement.

PubMed

Morris, William Z; Chen, Jason Y; Cooperman, Daniel R; Liu, Raymond W

2015-02-04

Many radiographic indices that are used to assess adolescents for femoroacetabular impingement rely on an ossified posterior acetabular wall. A recent study identified a secondary ossification center in the posterior rim of the acetabulum, the ossification of which may affect perceived acetabular coverage. The purpose of this study was to characterize ossification of the posterior rim of the acetabulum with use of a longitudinal radiographic study and quantify its impact on the radiographic assessment of femoroacetabular impingement. In this study, we utilized a historical collection of annual radiographs made in a population of healthy adolescents. Six hundred and twelve anteroposterior radiographs of the left hip of ninety-eight patients were reviewed to identify the appearance, duration, and fusion of the secondary ossification center in the posterior rim of the acetabulum. The center-edge angle was then measured before appearance and after fusion of the secondary ossification center in a subset of ten patients who had <5° of rotation on all radiographs. The secondary ossification center in the posterior rim was identified in seventy-three of the ninety-eight subjects, with no significant difference between the sexes. The mean patient age at the time of radiographic appearance of this secondary ossification center was fourteen years for males and twelve years for females. The mean duration of radiographic appearance was ten months for both sexes. Serial center-edge angles were measured in a subset of ten patients, and they increased during posterior rim ossification by a mean of 4.1°. The secondary ossification center in the posterior rim of the acetabulum (the posterior rim sign) is a common radiographic finding that reliably appears for ten months around the time of triradiate closure. Posterior rim ossification led to a mean increase of 4° of perceived acetabular coverage through the center-edge angle. Given the narrow margin between normal coverage (33° to 36°) and acetabular overcoverage (>40°), the use of radiographs in adolescents with incompletely ossified hips may lead to misinterpretation of acetabular coverage. In patients with open triradiate cartilage, magnetic resonance imaging may be considered for the assessment of femoroacetabular impingement. The posterior rim ossification sign is a normal finding in adolescent hip development and has important implications for the proper evaluation of femoroacetabular impingement. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

Outcomes of different bearings in total hip arthroplasty - implant survival, revision causes, and patient-reported outcome.

PubMed

Varnum, Claus

2017-03-01

Total hip arthroplasty (THA) is a common and successful treatment of patients suffering from severe osteoarthritis that significantly reduces pain and improves hip function and quality of life. Traditionally, the outcome of THA has been evaluated by orthopaedic surgeons and assessed in morbidity and mortality rates, and implant survival. As patients and surgeons may assess outcome after THA differently, patient-reported outcomes (PROMs) have gained much more interest and are today recognized as very important tools for evaluating the outcome and satisfaction after THA. One of the prognostic factors for the outcome of THA is the type of bearings. This PhD thesis focuses on the influence of different types of bearings on implant survival, revision causes, PROMs, and noises from THA. The aims of the thesis were: Study I: To examine the revision risk and to investigate the causes of revision of cementless ceramic-on-ceramic (CoC) THAs comparing them to those of "standard" metal-on-polyethylene (MoP) THAs. Study II: To compare the six-year revision risk for metal-on-metal (MoM) with that for MoP bearings in cementless stemmed THA, and further to study the revision risk for different designs of stemmed MoM THAs and the causes of revision. Study III: To examine the association between CoC, MoM, and MoP bearings and both generic and disease-specific PROMs, and furthermore to examine the incidence and types of noises from the three types of bearings and identify the effect of noises on PROM scores. In study I and III, we used data from the Danish Hip Arthroplasty Registry combined with data from the Civil Registration System and the Danish National Patient Registry. In study II, data from the Nordic Arthroplasty Register Association, containing data from hip arthroplasty registries in Denmark, Norway, Sweden, and Finland, was used. In study I, 11,096 patients operated from 2002 through 2009 with cementless THA were included. Of these, 16% had CoC THA and 84% had MoP THA. At 8.7-year follow-up, no difference in RR of revision for any cause was found for CoC compared to MoP THA. One cause of revision related only to CoC THA is ceramic fracture. Medical records were reviewed for patients who had revision surgery due to component failure, and six patients (0,34%) had been revised due to ceramic fracture. No other difference in prevalence of causes of revision was found when comparing CoC to MoP THA. Study II included 32,678 patients who were operated from 2002 through 2010 with cementless stemmed THA with either MoM bearings (11,567 patients, 35%) or MoP bearings (21,111 patients, 65%). At six-year follow-up, the RR of revision for any cause was significantly higher for MoM compared to MoP THA. When comparing different combinations of cup/stem with MoM to MoP bearings, there was an increased RR of revision for any cause for the ASR/Summit, ASR/Corail, and "other" combinations. There was a higher prevalence of revision due to aseptic loosening for MoM compared to MoP THA. In contrast, the prevalence of revision due to dislocation was lower for MoM THA. In study III, a set of questionnaires including HOOS, EQ-5D, UCLA activity score, and a questionnaire about noises from the THA was sendt to patients having THA with CoC, MoM, or MoP bearings. The response rate was 85% and among the 3,089 patients responding, 45% received CoC, 17% MoM, and 38% MoP THA. No differences in mean subscale scores were found for CoC and MoM compared to MoP THA, except for CoC THA that had a lower mean HOOS symptoms score than MoP THA. 27% of patients with CoC, 29% of patients with MoM, and 12% of patients with MoP bearings had experienced noises from the THA. For the three types of bearings, PROM scores from patients with noisy THA were significantly lower when compared to silent MoP THA, except for noisy CoC and MoM THA that had the same mean UCLA activity score as silent MoP THA.

Use of a Dual Mobility Socket to Manage Total Hip Arthroplasty Instability

PubMed Central

Pibarot, Vincent; Vaz, Gualter; Chevillotte, Christophe; Béjui-Hugues, Jacques

2008-01-01

Unconstrained tripolar hip implants provide an additional bearing using a mobile polyethylene component between the prosthetic head and the outer metal shell. Such a design increases the effective head diameter and therefore is an attractive option in challenging situations of unstable total hip arthroplasties. We report our experience with 54 patients treated using this dual mobility implant in such situations. We ascertained its ability to restore and maintain stability, and examined component loosening and component failure. At a minimum followup of 2.2 years (mean, 4 years; range, 2.2–6.8 years), one hip had redislocated 2 months postoperatively and was managed successfully without reoperation by closed reduction with no additional dislocation. Two patients required revision of the implant because of dislocation at the inner bearing. Technical errors were responsible for these failures. Three patients had reoperations for deep infections. The postoperative radiographs at latest followup showed very satisfactory osseointegration of the acetabular component because no radiolucent line or osteolysis was reported. Use of this unconstrained tripolar design was successful in restoring and maintaining hip stability. We observed encouraging results at short-term followup regarding potential for loosening or mechanical failures. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18780135

Computer-assisted total hip arthroplasty: coding the next generation of navigation systems for orthopedic surgery.

PubMed

Renkawitz, Tobias; Tingart, Markus; Grifka, Joachim; Sendtner, Ernst; Kalteis, Thomas

2009-09-01

This article outlines the scientific basis and a state-of-the-art application of computer-assisted orthopedic surgery in total hip arthroplasty (THA) and provides a future perspective on this technology. Computer-assisted orthopedic surgery in primary THA has the potential to couple 3D simulations with real-time evaluations of surgical performance, which has brought these developments from the research laboratory all the way to clinical use. Nonimage- or imageless-based navigation systems without the need for additional pre- or intra-operative image acquisition have stood the test to significantly reduce the variability in positioning the acetabular component and have shown precise measurement of leg length and offset changes during THA. More recently, computer-assisted orthopedic surgery systems have opened a new frontier for accurate surgical practice in minimally invasive, tissue-preserving THA. The future generation of imageless navigation systems will switch from simple measurement tasks to real navigation tools. These software algorithms will consider the cup and stem as components of a coupled biomechanical system, navigating the orthopedic surgeon to find an optimized complementary component orientation rather than target values intraoperatively, and are expected to have a high impact on clinical practice and postoperative functionality in modern THA.

A new technique for radiographic measurement of acetabular cup orientation.

PubMed

Derbyshire, Brian; Diggle, Peter J; Ingham, Christopher J; Macnair, Rory; Wimhurst, James; Jones, Henry Wynn

2014-02-01

Accurate radiographic measurement of acetabular cup orientation is required in order to assess susceptibility to impingement, dislocation, and edge loading wear. In this study, the accuracy and precision of a new radiographic cup orientation measurement system were assessed and compared to those of two commercially available systems. Two types of resurfacing hip prostheses and an uncemented prosthesis were assessed. Radiographic images of each prosthesis were created with the cup set at different, known angles of version and inclination in a measurement jig. The new system was the most accurate and precise and could repeatedly measure version and inclination to within a fraction of a degree. In addition it has a facility to distinguish cup retroversion from anteversion on anteroposterior radiographs. © 2013.

21 CFR 878.3300 - Surgical mesh.

Code of Federal Regulations, 2012 CFR

2012-04-01

... GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3300 Surgical mesh. (a) Identification... acetabular and cement restrictor mesh used during orthopedic surgery. (b) Classification. Class II. ...

21 CFR 878.3300 - Surgical mesh.

Code of Federal Regulations, 2014 CFR

2014-04-01

... GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3300 Surgical mesh. (a) Identification... acetabular and cement restrictor mesh used during orthopedic surgery. (b) Classification. Class II. ...

21 CFR 878.3300 - Surgical mesh.

Code of Federal Regulations, 2010 CFR

2010-04-01

... GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3300 Surgical mesh. (a) Identification... acetabular and cement restrictor mesh used during orthopedic surgery. (b) Classification. Class II. ...

21 CFR 878.3300 - Surgical mesh.

Code of Federal Regulations, 2013 CFR

2013-04-01

... GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3300 Surgical mesh. (a) Identification... acetabular and cement restrictor mesh used during orthopedic surgery. (b) Classification. Class II. ...

21 CFR 878.3300 - Surgical mesh.

Code of Federal Regulations, 2011 CFR

2011-04-01

... GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3300 Surgical mesh. (a) Identification... acetabular and cement restrictor mesh used during orthopedic surgery. (b) Classification. Class II. ...

Influence of undersized cementless hip stems on primary stability and strain distribution.

PubMed

Fottner, Andreas; Woiczinski, Matthias; Kistler, Manuel; Schröder, Christian; Schmidutz, Tobias F; Jansson, Volkmar; Schmidutz, Florian

2017-10-01

Undersizing of cementless hip stems is a risk factor for aseptic loosening and early subsidence. The purpose of this study was to evaluate the effects of undersized stems and determine whether a biomechanical study can predict the clinical results. Three consecutive sizes of a clinically proven stem (CLS Spotorno) were implanted into six composite femora (size large, Sawbones ® ), respectively. According to the Canal Fill Index (CFI), two stems (size 11.25 and 12.5) were undersized (CFI < 80%) and one stem (size 13.75) had an appropriate size (CFI > 80%). The primary stability was evaluated by measurement of 3-dimensional (3D)-micromotions under physiological adapted load and surface strains were recorded before and after implantation to detect stress-shielding processes. Both undersized stems revealed significantly higher micromotions in all regions compared to the appropriate stem. The highest micromotions were registered at the distal tip of the three stem sizes. The changes in surface strain did not show a significant difference between the three stem sizes, but the highest strain reduction was observed proximally indicating a tendency for stress shielding. This study confirms the clinical assumption that undersized stem result in a significantly reduced primary stability. Furthermore, in vitro studies allow to determine the effects of undersizing and stress shielding processes.

Evaluation of Osseous Integration of PVD-Silver-Coated Hip Prostheses in a Canine Model

PubMed Central

Hauschild, Gregor; Hardes, Jendrik; Gosheger, Georg; Blaske, Franziska; Wehe, Christoph; Karst, Uwe; Höll, Steffen

2015-01-01

Infection associated with biomaterials used for orthopedic prostheses remains a serious complication in orthopedics, especially tumor surgery. Silver-coating of orthopedic (mega)prostheses proved its efficiency in reducing infections but has been limited to surface areas exposed to soft tissues due to concerns of silver inhibiting osseous integration of cementless stems. To close this gap in the bactericidal capacity of silver-coated orthopedic prostheses extension of the silver-coating on surface areas intended for osseous integration seems to be inevitable. Our study reports about a PVD- (physical-vapor-deposition-) silver-coated cementless stem in a canine model for the first time and showed osseous integration of a silver-coated titanium surface in vivo. Radiological, histological, and biomechanical analysis revealed a stable osseous integration of four of nine stems implanted. Silver trace elemental concentrations in serum did not exceed 1.82 parts per billion (ppb) and can be considered as nontoxic. Changes in liver and kidney functions associated with the silver-coating could be excluded by blood chemistry analysis. This was in accordance with very limited metal displacement from coated surfaces observed by laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) 12 months after implantation. In conclusion our results represent a step towards complete bactericidal silver-coating of orthopedic prostheses. PMID:25695057

Pre-clinical evaluation of the mechanical properties of a low-stiffness cement-injectable hip stem.

PubMed

Eldesouky, Ibrahim; Harrysson, Ola; Marcellin-Little, Denis J; West, Harvey; El-Hofy, Hassan

2017-11-01

In total hip arthroplasty (THA), the femoral stem can be fixed with or without bone cement. Cementless stem fixation is recommended for young and active patients as it eliminates the risk of loss of fixation at the bone-cement and cement-implant interfaces. Cementless fixation, however, suffers from a relatively high early revision rate. In the current research, a novel low-stiffness hip stem was designed, fabricated and tested. The stem design provided the option to inject biodegradable bone cement that could enhance initial stem stability. The stem was made of Ti6Al4V alloy. The proximal portion of the stem was porous, with cubic cells. The stem was fabricated using electron beam melting (EBM) technology and tested in compression and bending. Finite-element analysis was used to evaluate stem performance under a dynamic load representing a stair descending cycle and compare it to the performance of a solid stem with similar geometry. The von Mises stresses and maximum principal strains generated within the bone increased after porous stem insertion compared to solid stem insertion. The low-modulus stem tested in this study has acceptable mechanical properties and generates strain patterns in bone that appear compatible with clinical use.

Increased migration of uncemented acetabular cups in female total hip arthroplasty patients with low systemic bone mineral density. A 2-year RSA and 8-year radiographic follow-up study of 34 patients.

PubMed

Finnilä, Sami; Moritz, Niko; SvedströM, Erkki; Alm, Jessica J; Aro, Hannu T

2016-02-01

Low bone mineral density (BMD) may jeopardize the initial component stability and delay osseointegration of uncemented acetabular cups in total hip arthroplasty (THA). We measured the migration of uncemented cups in women with low or normal BMD. We used radiostereometric analysis (RSA) to measure the migration of hydroxyapatite-coated titanium alloy cups with alumina-on-alumina bearings in THA of 34 female patients with a median age of 64 (41-78) years. 10 patients had normal BMD and 24 patients had low systemic BMD (T-score ≤ -1) based on dual-energy X-ray absorptiometry (DXA). Cup migration was followed with RSA for 2 years. Radiographic follow-up was done at a median of 8 (2-10) years. Patients with normal BMD did not show a statistically significant cup migration after the settling period of 3 months, while patients with low BMD had a continuous proximal migration between 3 and 12 months (p = 0.03). These differences in cup migration persisted at 24 months. Based on the perceived risk of cup revision, 14 of the 24 cases were "at risk" (proximal translation of 0.2 to 1.0 mm) in the low-BMD group and 2 of the 10 cases were "at risk" in the normal-BMD group (odds ratio (OR) = 8.0, 95% CI: 1.3-48). The radiographic follow-up showed no radiolucent lines or osteolysis. 2 cups have been revised for fractures of the ceramic bearings, but none for loosening. Low BMD contributed to cup migration beyond the settling period of 3 months, but the migrating cups appeared to osseointegrate eventually.

A novel combined hemipelvic endoprosthesis for peri-acetabular tumours involving sacroiliac joint: a finite element study.

PubMed

Wang, Bo; Sun, Peidong; Xie, Xianbiao; Wu, Weidong; Tu, Jian; Ouyang, Jun; Shen, Jingnan

2015-11-01

Our aim was to introduce a novel combined hemipelvic endoprosthesis for pelvic reconstruction after Enneking type I/II/IV resection and to evaluate the biomechanical properties of the endoprosthesis using finite element analysis. A three-dimensional finite element model of the postoperative pelvis was developed based on computed tomography (CT) images of the patient with the best post-operative limb function. A force of 400 N was applied along the longitudinal axis of the normal and post-operative pelvis for two positions: standing on two feet and sitting. Stress-distribution analysis was performed in both positions, and results were compared. Prosthesis improvements were simulated by intervertebral fusion and extra screw fixation. In the normal pelvis, stress distributions were mostly concentrated on the superior area of the acetabulum, arcuate line, sacroiliac joint and sacral midline in both static conditions, and peak stresses of 1.52 MPa and 4.53 MPa were observed at the superior area of the greater sciatic notch and ischial tuberosity, respectively. For the reconstructed hemipelvis, stress distributions were concentrated on the connecting rods of the acetabular component and the proximal segment of the pedicle rods, and peak stresses of 252 MPa and 213 MPa were observed on the proximal pedicle rods of the fourth lumbar vertebra for standing and sitting, respectively. Interbody fusion of the fourth and fifth lumbar vertebrae and extra screw fixation to the sacrum decreased the peak stresses by 33.0 % and 18.3 % while standing and by 10.8 % and 6.6 % while sitting. Reconstruction with combined hemipelvic endoprosthesis after types I/II/IV resection of the pelvis fulfilled physiological and biomechanical demands of the hemipelvis and yielded good biomechanical characteristics.

Confocal Raman spectroscopic analysis of cross-linked ultra-high molecular weight polyethylene for application in artificial hip joints.

PubMed

Pezzotti, Giuseppe; Kumakura, Tsuyoshi; Yamada, Kiyotaka; Tateiwa, Toshiyuki; Puppulin, Leonardo; Zhu, Wenliang; Yamamoto, Kengo

2007-01-01

Confocal spectroscopic techniques are applied to selected Raman bands to study the microscopic features of acetabular cups made of ultra-high molecular weight polyethylene (UHMWPE) before and after implantation in vivo. The micrometric lateral resolution of a laser beam focused on the polymeric surface (or subsurface) enables a highly resolved visualization of 2-D conformational population patterns, including crystalline, amorphous, orthorhombic phase fractions, and oxidation index. An optimized confocal probe configuration, aided by a computational deconvolution of the optical probe, allows minimization of the probe size along the in-depth direction and a nondestructive evaluation of microstructural properties along the material subsurface. Computational deconvolution is also attempted, based on an experimental assessment of the probe response function of the polyethylene Raman spectrum, according to a defocusing technique. A statistical set of high-resolution microstructural data are collected on a fully 3-D level on gamma-ray irradiated UHMWPE acetabular cups both as-received from the maker and after retrieval from a human body. Microstructural properties reveal significant gradients along the immediate material subsurface and distinct differences are found due to the loading history in vivo, which cannot be revealed by conventional optical spectroscopy. The applicability of the confocal spectroscopic technique is valid beyond the particular retrieval cases examined in this study, and can be easily extended to evaluate in-vitro tested components or to quality control of new polyethylene brands. Confocal Raman spectroscopy may also contribute to rationalize the complex effects of gamma-ray irradiation on the surface of medical grade UHMWPE for total joint replacement and, ultimately, to predict their actual lifetime in vivo.