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Sample records for cemented femoral stem

  1. Cemented femoral stems in patients with DDH.

    PubMed

    Garcia-Cimbrelo, E

    2007-01-01

    Total hip arthroplasty is the procedure of choice for most adult patients with symptomatic arthrosis secondary to developmental dysplasia (DDH), but it requires complex reconstructive techniques, is usually performed in young patients, and has an increased risk of complications. THA is indicated in presence of severe pain and when osteotomy is contraindicated. The complexity of surgery is related to the degree of dysplasia. Anatomic abnormalities in the acetabulum and femur are the cause of the complexity and complications of this procedure. Acetabular bone deficiency requires reconstructive techniques before implanting the cup at the anatomic acetabular location, such as bone autograft augmentation, implanting the cup at higher level of the hip center and cup medialization. Femoral shortening and special cemented or uncemented stems are currently used to avoid intraoperative complications. While a cemented stem needs metaphyseal femoral shortening, subtrochanteric shortening requires a cementless stem. Because of these patients' age, alternative bearing surfaces, such as alumina-on-alumina couples are recommended when possible. Although the long-term results of total hip arthroplasty in DDH are inferior to those in a general population, the results show a high level of pain relief and functional improvement.

  2. No benefit of a proximal stem centralizer in cementing of a femoral prosthesis in human cadavers

    PubMed Central

    2011-01-01

    Background and purpose A proximal stem centralizer may be beneficial regarding cementing pressures, cement penetration, and stem alignment. We measured these parameters when cementing a mat-surfaced femoral component with and without the use of a proximal stem centralizer. Material and methods 8 femoral prostheses with proximal centralizers and 8 femoral prostheses without proximal centralizers were cemented according to third-generation cementing technique in 8 pairs of embalmed cadaveric femora. We recorded intramedullary pressures (peak levels, the area under the pressure curves and mean pressure) with 6 pressure transducers during stem cementation. Computer tomographic scanning of specimens was performed to evaluate stem alignment after surgery. Thickness of the cement mantle, cement penetration, and stem centralization at the metaphyseal part of the femur were measured on cross sections using stereology. Results There were no statistically significant differences in measured pressure and cement penetration values between the groups. There was similar cement distribution around the stems; however, in using a proximal centralizer, the cement mantle tended to be thinner laterally. Moreover, we found a larger variation in stem alignment on lateral projection in the proximal centralizer group. Interpretation No benefits regarding intramedullary pressures and cement penetration were obtained from cementation of a straight stem with a proximal stem centralizer. However, there was an increased risk of inferior stem positioning in the reamed medullary cavity using the centralizing device. PMID:21434768

  3. Vacuum-mixing cement does not decrease overall porosity in cemented femoral stems: AN IN VITRO LABORATORY INVESTIGATION

    PubMed Central

    Messick, K. J.; Miller, M. A.; Damron, L. A.; Race, A.; Clarke, M. T.; Mann, K. A.

    2008-01-01

    The role of vacuum mixing on the reduction of porosity and on the clinical performance of cemented total hip replacements remains uncertain. We have used paired femoral constructs prepared with either hand-mixed or vacuum-mixed cement in a cadaver model which simulated intra-operative conditions during cementing of the femoral component. After the cement had cured, the distribution of its porosity was determined, as was the strength of the cement-stem and cement-bone interfaces. The overall fraction of the pore area was similar for both hand-mixed and vacuum-mixed cement (hand 6%; vacuum 5.7%; paired t-test, p = 0.187). The linear pore fractions at the interfaces were also similar for the two techniques. The pore number-density was much higher for the hand-mixed cement (paired t-test, p = 0.0013). The strength of the cement-stem interface was greater with the hand-mixed cement (paired t-test, p = 0.0005), while the strength of the cement-bone interface was not affected by the conditions of mixing (paired t-test, p = 0.275). The reduction in porosity with vacuum mixing did not affect the porosity of the mantle, but the distribution of the porosity can be affected by the technique of mixing used. PMID:17785755

  4. Radiographic evaluation of cementation technique using polished, conical, triple-tapered femoral stem in hip arthroplasty.

    PubMed

    Schuroff, Ademir Antônio; Deeke, Mark; Pedroni, Marco Antônio; Lupselo, Fernando Silva; Kunz, Rodrigo Ernesto; Lima, Alexandre Matos

    2017-01-01

    To radiographically evaluate the quality of cementation and implantation technique using a polished, triple-tapered femoral stem in total hip arthroplasty (THA). Retrospective study with radiographic evaluation of 86 hips in 83 patients who underwent to primary THA with the triple-tapered cemented femoral stem C-Stem (DePuy Orthopedics, Warsaw, Indiana). Cases with at least one-year of follow-up were included, and data related to preoperative, immediate postoperative, and late postoperative radiographic evolution were recorded. This study analyzed, among others, the proximal femoral anatomy, the quality of cementation as described by Barrack, and the implant positioning. Cementation was also evaluated and quantified in the Gruen zones with one-year of follow-up. The mean age was 62.85 years. Proximal femoral anatomical conformation was Dorr type A in 34 (39.53%) cases, type B in 52 (60.46%), and no type C cases were found. Five (5.81%) cases were defined as type A by Barrack's cementation classification system, 46 (56.49%) type B, 27 (31.40%) type C, and eight (9.30%) type D. The greatest cement mantle thickness was observed in zones four (15.53 mm) and 11 (15.64 mm), and the smallest in zone nine (3.51 mm). Positioning in varus was observed in eight (9.3%) cases, valgus in 25 (29%), forward deviation in two (5%), and backward deviation in 55 (63.95%). The C-Stem femoral system presented satisfactory results related to cementation pattern, positioning, osteolysis, and stress shielding with regard to literature referring to double-tapered or triple-tapered models, demonstrating to be a safe method, with a predictable and reliable cementing pattern.

  5. Radiographic grading of femoral stem cementation in hip arthroplasty

    PubMed Central

    Garcia, Flávio Luís; Sugo, Arthur Tomotaka; Picado, Celso Hermínio Ferraz

    2013-01-01

    OBJECTIVE: To determine intra and interobserver agreement of the grading system for femoral cementation in hip arthroplasty proposed by Barrack. METHODS: Immediate anteroposterior and lateral postoperative radiographs of 55 primary total hip arthroplasties were assessed by two observers familiar with the use of this grading system. The assessments were performed on two separate occasions by each observer and independently. The statistical analysis measured the Kappa coefficient, which determines the degree of agreement between tests with categorical variables. RESULTS: Intraobserver Kappa coefficient varied from 0.43 to 0.68, demonstrating moderate to substantial strength of agreement; interobserver Kappa coefficient varied from 0.19 to 0.44, demonstrating slight to moderate strength of agreement. CONCLUSION: Intra and particularly interobserver agreement are limited in this grading system, even when used by trained individuals. Level of Evidence III, Study of nonconsecutive patients; without consistently applied reference "gold" standard. PMID:24453640

  6. More complications with uncemented than cemented femoral stems in total hip replacement for displaced femoral neck fractures in the elderly

    PubMed Central

    Chammout, Ghazi; Muren, Olle; Laurencikas, Evaldas; Bodén, Henrik; Kelly-Pettersson, Paula; Sjöö, Helene; Stark, André; Sköldenberg, Olof

    2017-01-01

    Background and purpose Total hip replacement (THR) is the preferred method for the active and lucid elderly patient with a displaced femoral neck fracture (FNF). Controversy still exists regarding the use of cemented or uncemented stems in these patients. We compared the effectiveness and safety between a modern cemented, and a modern uncemented hydroxyapatite-coated femoral stem in patients 65–79 years of age who were treated with THR for displaced FNF. Patients and methods In a single-center, single-blinded randomized controlled trial, we included 69 patients, mean age 75 (65–79) and with a displaced FNF (Garden III–IV). 35 patients were randomized to a cemented THR and 34 to a reverse-hybrid THR with an uncemented stem. Primary endpoints were: prevalence of all hip-related complications and health-related quality of life, evaluated with EuroQol-5D (EQ-5D) index up to 2 years after surgery. Secondary outcomes included: overall mortality, general medical complications, and hip function. The patients were followed up at 3, 12, and 24 months. Results According to the calculation of sample size, 140 patients would be required for the primary endpoints, but the study was stopped when only half of the sample size was included (n = 69). An interim analysis at that time showed that the total number of early hip-related complications was substantially higher in the uncemented group, 9 (among them, 3 dislocations and 4 periprosthetic fractures) as compared to 1 in the cemented group. The mortality and functional outcome scores were similar in the 2 groups. Interpretation We do not recommend uncemented femoral stems for the treatment of elderly patients with displaced FNFs. PMID:27967333

  7. The influence of proximal stem geometry and surface finish on the fixation of a double-tapered cemented femoral stem.

    PubMed

    Sangiorgio, Sophia N; Longjohn, Donald B; Dorr, Lawrence D; Ebramzadeh, Edward

    2011-01-04

    In this study, the in vitro fixation of four otherwise identical double-tapered stem-types, varying only in surface finish (polished or matte) and proximal stem geometry (with or without flanges) were compared under two conditions. First, four specimens of each stem type were tested with initially bonded stem-cement interfaces, representing early post-operative conditions. Then, simulating conditions a few weeks to months later, stems were implanted in unused synthetic femurs, with a thin layer coating the stem to prevent stem-cement adhesion. Per-cycle motions were measured at both cement interfaces throughout loading. Overall, surface finish had the smallest relative effect on fixation compared to flanges. Flanges increased axial fixation by 22 μm per-cycle, regardless of surface finish (P=0.01). Further, all stems moved under dynamic load at the stem-cement interface during the first few cycles of loading, even without a thin film. The results indicate that flanges have a greater effect on fixation than surface finish, and therefore adverse findings about matte surfaces should not necessarily apply to all double-tapered stems. Specifically, dorsal flanges enhance the stability of a tapered cemented femoral stem, regardless of surface finish.

  8. Cement-in-cement stem revision for Vancouver type B periprosthetic femoral fractures after total hip arthroplasty. A 3-year follow-up of 23 cases.

    PubMed

    Briant-Evans, Toby W; Veeramootoo, Darmaraja; Tsiridis, Eleftherios; Hubble, Matthew J

    2009-10-01

    Revision surgery for periprosthetic femoral fractures around an unstable cemented femoral stem traditionally requires removal of existing cement. We propose a new technique whereby a well-fixed cement mantle can be retained in cases with simple fractures that can be reduced anatomically when a cemented revision is planned. This technique is well established in femoral stem revision, but not in association with a fracture. We treated 23 Vancouver type B periprosthetic femoral fractures by reducing the fracture and cementing a revision stem into the pre-existing cement mantle, with or without supplementary fixation. 3 patients died in the first 6 months for reasons unrelated to surgery. In addition, 1 was too frail to attend follow-up and was therefore excluded from the study, and 1 patient underwent revision surgery for a nonunion. The remaining 18 cases all healed with radiographic union after an average time of 4.4 (2-11) months. There was no sign of loosening or subsidence of the revision stems within the old cement mantle in any of these cases at the most recent follow-up after an average of 3 (0.3-9) years. Our results support the use of the cement-in-cement revision in anatomically reducible periprosthetic fractures with a well-preserved pre-existing cement mantle. This technique is particularly useful for the elderly patient and for those who are not fit for prolonged surgical procedures.

  9. Metal debris concentrations in soft tissues adjacent to loosened femoral stems is higher in uncemented than cemented implants

    PubMed Central

    2014-01-01

    Background There are still many questions related to aseptic femoral stem loosening. Systemic and local immune responses to the implanted “foreign body” is one of the reasons for loosening. The purpose of the study was to measure metal ion concentration (Ti, Co, Cr, Mo, Ni, Al) around loosened femoral stems and compare their levels around uncemented and cemented implants. Methods This paper reports 50 hips operated for isolated stem loosening, in 50 patients at the mean age of 57 years (from 21 to 87). There were 25 cemented (Co,Cr29,Mo,Ni) and 25 uncemented (Ti, Al) stems. The mean follow-up from primary hip replacement to revision was 10.1 years (from 0.5 to 17). During the procedure, scar tissue around the stem was taken for analysis of metal ions. Results The concentrations of titanium and aluminium in soft tissues around uncemented loosened stems were higher than cemented ones (p < 0.001, p < 0.001 respectively). However, no statistically significant differences were observed between both types of stems in terms of ions of the metal of which cemented implants had been made of (Co, Cr, Mo, Ni). Conclusions In soft tissue around a loosened stem, the concentrations of metal ions from implants are much higher in case of uncemented stems than of cemented ones. Metal ions from vitalium femoral heads were found around uncemented stems in similar values to cemented streams. PMID:25098913

  10. [Use of the anatomical cemented femoral stem SAS I: mid-term results].

    PubMed

    Mikláš, M; Pink, M; Valoušek, T

    2015-01-01

    PURPOSE OF THE STUDY In view of increasing interest in a relationship between the surface of an implant and its behaviour and longevity in total hip arthroplasty (THA), the aim of this study is to present the clinical and radiographic results, as well as complications, of hip replacement surgery using the cemented femoral stem SAS I. MATERIAL AND METHODS A total of 298 cemented femoral stems SAS I were implanted in 275 patients at our department between 1996 and 2005. The patient average age was 72.1 years, with the range from 64 to 92 years. The pre-operative diagnoses were as follows: primary osteoarthritis in 179 (30.1%); post-dysplastic osteoarthritis in 41 (13.7%); femoral neck fracture in 44 (14.8%); avascular necrosis of the femoral head in 23 (7.7%); rheumatoid arthritis in nine (3%) and other causes in two (0.7%) patients. Of the 275 patients who had the surgery, 186 (204 THAs) underwent clinical and X-ray examination at an average follow-up of 11.5 years (range, 8 to 17 years). The clinical results were used to calculate the Harris hip score and radiographic evaluation was based on antero-posterior views. RESULTS The group of 186 assessed patients (204 THAs) comprised 106 women and 80 men, who were on average 85.4 years old on evaluation (range, 72 to 92 years). Of the remaining patients, 62 patients (64 THAs) died from causes unrelated to the surgery and 27 patients (30 THAs) were lost to follow-up. The functional outcome of surgery assessed by the Harris hip score was excellent in 61 (32.8%), good in 94 (50.5%), satisfactory in 26 (14%) and poor in five (2.7%) patients. The 93.1% SAS I stem longevity was recorded in relation to aseptic loosening; reimplantation for this indication was performed in 14 THAs. No revision surgery for failure due to valgus/varus deviations of the stem was carried out. Of the 204 hips, 188 had femoral stems aligned in neutral, 12 (5.9%) in valgus and four (2%) in varus positions. DISCUSSION The anatomical femoral stem SAS I

  11. Early Subsidence Predicts Failure of a Cemented Femoral Stem With Minor Design Changes.

    PubMed

    Johanson, Per-Erik; Antonsson, Martin; Shareghi, Bita; Kärrholm, Johan

    2016-10-01

    Radiostereometry (RSA) measurements of early micromotion can predict later failure in hip and knee prostheses. In hip implants, RSA has been particularly helpful in the evaluation of composite-beam stem designs. The Spectron EF Primary stem (Smith & Nephew, London, UK) has shown inferior performance compared with its predecessors in both clinical studies and registry reports. Early RSA studies have shown somewhat greater subsidence for the Spectron EF Primary stem compared with the earlier Spectron EF, but still within boundaries considered to be safe. Our primary research question was whether stem subsidence and rotation for this stem design measured with RSA at 2 years can predict later stem failure. A secondary question was whether high femoral stem offset and small stem sizes, both features specific to the Spectron EF Primary stem compared with its predecessors, are associated with stem failure rate. Two hundred forty-seven hips (209 patients with median age 63 years [range, 29-80 years], 65% female, and 77% primary osteoarthritis) with a valid RSA examination at 2 years were selected from four different RSA studies (totaling 279 hips in 236 patients) in our department. The studies were primarily aimed at evaluating cup fixation, bone cement, and polyethylene types. All study patients received a cemented Spectron EF Primary stem. The selected hips had complete followup until stem failure, death, or the end of the followup period. Stem failure was defined as revision of a loose femoral stem or radiological failure with significant osteolysis in Gruen zones 2 to 6. Cox regression analyses were performed to evaluate if stem subsidence and rotation after 2 years, adjusted for age, sex, stem size, standard/high stem offset, and conventional/highly crosslinked polyethylene, could predict later clinical aseptic failure of the stem. We identified 32 stem failures (27 revisions, five radiological failures) at 14 years median followup (range, 3-18 years). Ten-year stem

  12. Five-year DEXA study of 88 hips with cemented femoral stem.

    PubMed

    Digas, Georgios; Kärrholm, Johan

    2009-12-01

    We performed repeated dual-energy X-ray absorptiometry (DEXA) measurements over five years in a homogeneous patient population to study the effect of a cemented stem on proximal femoral bone remodelling. Data from 88 patients (88 hips) implanted with total hip arthroplasty (THA) prostheses were extracted from three randomised studies. Femoral bone mineral density (BMD) was measured using a Lunar DPX-IQ densitometer for five years postoperatively. At one year the BMD changes had decreased between -2.0% [region of interest (ROI) 1] and -11.5% (ROI 7). During the follow-up period the BMD initially increased during the second year and thereafter decreased again in ROIs 5, 6 and 7. The loss of BMD at five years was more pronounced in region 7 (12.9%) and decreased with increasing age, total hip replacement (THR) on the right side and decreasing weight of the patient. We found that after the initial phase of early bone loss a period of recovery follows. Thereafter the BMD decreases again, which probably reflects the normal ageing of bone after uncomplicated cemented THA.

  13. An in-vitro investigation of the CPS-Plus femoral stem: influence of the proximal centraliser on cement pressurisation during stem insertion.

    PubMed

    Gozzard, Charles; Gheduzzi, Sabina; Miles, Anthony W; Learmonth, Ian D

    2003-04-01

    The CPS-Plus stem is designed for use with a proximal and distal stem centraliser. This in-vitro study examined the cement pressurisation achieved during insertion of the CPS-Plus femoral stem into a model femur. Cement pressures were measured at proximal, mid and distal stem levels. Pressures were recorded during insertion of the CPS-Plus stem with both proximal and distal centralisers and compared with those achieved when only a distal centraliser was used with digital occlusion of the proximal femur. The CPS-Plus with a proximal centraliser generated significantly greater cement pressures than the CPS-Plus without a proximal centraliser at proximal and mid-stem regions. The use of a proximal stem centraliser may improve the cement-bone interdigitation and shear strength at the cement-bone interface, particularly in the region of the proximal femur.

  14. Use of a genetic algorithm for multiobjective design optimization of the femoral stem of a cemented total hip arthroplasty.

    PubMed

    Ishida, Toshimasa; Nishimura, Ikuya; Tanino, Hiromasa; Higa, Masaru; Ito, Hiroshi; Mitamura, Yoshinori

    2011-04-01

    There are many designs of the femoral stem of a cemented total hip arthroplasty, and mechanical failure of the stem is caused by several factors related to the cement, such as failure of the cement. Optimization of the shape of the stem, especially multiobjective optimization, is required to solve these design problems because a cement fracture is caused by multiple factors. The objective of this study was to determine a stem geometry considering multiple factors at the same time. A three-dimensional finite element model of the proximal femur was developed from a composite femur. A total of four objective functions--two objective functions, the largest maximum principal stress of proximal and distal sections in the cement mantle, for each of the two boundary conditions, walking and stair climbing--were used. The neighborhood cultivation genetic algorithm was introduced to minimize these objective functions. The results showed that the geometry that leads to a decrease in the proximal cement stress and the geometry that leads to a decrease in the distal cement stress were not the same. However, the results of the walking and the stair climbing conditions matched. Five dominant stem designs were considered to be the Pareto solution, and one design was identified as the "better design" for all objective functions. It was shown that multiobjective optimization using a genetic algorithm may be used for optimizing the shape of the femoral stem in order to avoid cement fracture. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  15. A new cemented femoral stem: a prospective study of the Stryker accolade C with 2- to 5-year follow-up.

    PubMed

    Ajmal, Muhammad; Ranawat, Amar S; Ranawat, Chitranjan S

    2008-01-01

    This prospective study evaluates the short-term results of a recently released cemented femoral stem design in primary cemented and hybrid total hip arthroplasty (THA). There were 100 all-cemented and 100 hybrid THAs in the 2-year study group. Good to excellent results were obtained in 96%. There was one reoperation for recurrent dislocation in each cohort (1%) and one single-staged reoperation for sepsis in the cemented cohort. There were 47 THA available for 5-year follow-up. Good to excellent results were maintained in 98%. One additional patient had a revision because of late recurrent dislocation. This study has demonstrated excellent early results and safety with this cemented femoral stem. The features include a dual-wedge geometry with a 0.88-microm Ra surface roughness, proximal macro-normalizations, distal anti-rotation grooves, and an optimized head-and-neck ratio approaching 4:1 using a standard 28-mm head.

  16. A comparison of the use of uncemented hydroxyapatite-coated bipolar and cemented femoral stems in the treatment of femoral neck fractures: a case-control study.

    PubMed

    Bell, K R; Clement, N D; Jenkins, P J; Keating, J F

    2014-03-01

    We performed a case-control study to compare the rates of further surgery, revision and complications, operating time and survival in patients who were treated with either an uncemented hydroxyapatite-coated Corail bipolar femoral stem or a cemented Exeter stem for a displaced intracapsular fracture of the hip. The mean age of the patients in the uncemented group was 82.5 years (53 to 97) and in the cemented group was 82.7 years (51 to 99) We used propensity score matching, adjusting for age, gender and the presence or absence of dementia and comorbidities, to produce a matched cohort receiving an Exeter stem (n = 69) with which to compare the outcome of patients receiving a Corail stem (n = 69). The Corail had a significantly lower all-cause rate of further surgery (p = 0.016; odds ratio (OR) 0.18, 95% CI 0.04 to 0.84) and number of hips undergoing major further surgery (p = 0.029; OR 0.13, 95% CI 0.01 to 1.09). The mean operating time was significantly less for the Corail group than for the cemented Exeter group (59 min [12 to 136] vs 70 min [40 to 175], p = 0.001). The Corail group also had a lower risk of a peri-prosthetic fracture (p = 0.042; OR 0.19, 95% CI 0.01 to 1.42) . There was no difference in the mortality rate between the groups. There were significantly fewer complications in the uncemented group, suggesting that the use of this stem would result in a decreased rate of morbidity in these frail patients. Whether this relates to an improved functional outcome remains unknown.

  17. Fracture of the C-Stem cemented femoral component in revision hip surgery using bone impaction grafting technique: report of 9 cases.

    PubMed

    Buttaro, Martin; Comba, Fernando; Zanotti, Gerardo; Piccaluga, Francisco

    2015-01-01

    We present a series of 9 fractures of a C-Stem femoral component (6 long stems and 3 conventional stems) that had been implanted with the use of impaction bone grafting (IBG). The length of the long fractured stems was 240 mm in 4 cases and 200 mm in 2. The patients presented had an average BMI of 26.5 and an average of 2.7 previous hip surgeries (range 2-5 surgeries) before the stem fracture. A total of 5 cases presented with a metal mesh fracture in addition to the fractured stem. Bending of the stems or stem defects was not observed in any case. Typical fracture waves consistent with fatigue failure were clearly visible on all the cut surfaces, starting anterolaterally and propagating to the medial side. Although fatigue fracture of a modern cemented tapered polished femoral stem is a rare event, stress due to the absence of proximal femoral bone support could be sufficient to put this stem at a higher risk for fatigue fracture in non-obese patients.

  18. Initial Evaluation on Subsidence of Cemented Collarless Polished Tapered Stem Applied to the Patients with Narrow Femoral Medullar Canal

    PubMed Central

    Dairaku, Katsuyuki; Ishii, Masaji; Kobayashi, Shinji; Kawaji, Hiroyuki; Sasaki, Kan; Takakubo, Yuya; Takagi, Michiaki

    2010-01-01

    Purpose: The geometry of the proximal femur is one of the important factors for choosing the suitable stem. We have been applied cemented collarless polished tapered (CPT) stem to the patients with small femur. Radiographic evaluation was performed to access the clinical feature of the stem in early stage of the follow-up. Methods: One hundred total hip arthroplasties with CPT system were performed between October 2004 to February 2006. This study focused on the 53 cases to whom size 1 or smaller sized stem were implanted, and its post-operative period was 41 months (30-46 months). Morphologic classification of preoperative proximal femur, stem alignment, thickness of the cement mantle, cementing technique, subsidence of the stem, improvement in the bone-cement interface, and stress shielding were assessed. Results: The size of the inserted stem was X-SMALL in one case, SMALL in two cases, SIZE 0 in 12 cases, and SIZE 1 in 38 cases. Canal shape of proximal femur was stovepipe type in five cases, normal type in 43 cases, and champagne-flute type in five cases. There was no subsidence in eight cases. 44 stems subsided within 1 mm, one stem subsided 1 to 2 mm, and no stem subsided over 2 mm. In 39 of 45 cases, subsidence was appeared within six months after operation. Marked progressive and excessive subsidence was not seen after the two years of follow-up. Conclusions: Short term radiographic results of THA with CPT stem to small femur were satisfactory with less unfavorable radiographic findings, which imply contribution to longer survivorship of the stem. PMID:20448819

  19. Analysis of Femoral Components of Cemented Total Hip Arthroplasty

    NASA Astrophysics Data System (ADS)

    Singh, Shantanu; Harsha, A. P.

    2016-10-01

    There have been continuous on-going revisions in design of prosthesis in Total Hip Arthroplasty (THA) to improve the endurance of hip replacement. In the present work, Finite Element Analysis was performed on cemented THA with CoCrMo trapezoidal, CoCrMo circular, Ti6Al4V trapezoidal and Ti6Al4V circular stem. It was observed that cross section and material of femoral stem proved to be critical parameters for stress distribution in femoral components, distribution of interfacial stress and micro movements. In the first part of analysis, designs were investigated for micro movements and stress developed, for different stem materials. Later part of the analysis focused on investigations with respect to different stem cross sections. Femoral stem made of Titanium alloy (Ti6Al4V) resulted in larger debonding of stem at cement-stem interface and increased stress within the cement mantle in contrast to chromium alloy (CoCrMo) stem. Thus, CoCrMo proved to be a better choice for cemented THA. Comparison between CoCrMo femoral stem of trapezium and circular cross section showed that trapezoidal stem experiences lesser sliding and debonding at interfaces than circular cross section stem. Also, trapezium cross section generated lower peak stress in femoral stem and cortical femur. In present study, femur head with diameter of 36 mm was considered for the analysis in order to avoid dislocation of the stem. Also, metallic femur head was coupled with cross linked polyethylene liner as it experiences negligible wear compared to conventional polyethylene liner and unlike metallic liner it is non carcinogenic.

  20. Revision total hip arthroplasty: the femoral side using cemented implants.

    PubMed

    Holt, Graeme; Hook, Samantha; Hubble, Matthew

    2011-02-01

    Advances in surgical technique and implant technology have improved the ten-year survival after primary total hip arthroplasty (THA). Despite this, the number of revision procedures has been increasing in recent years, a trend which is predicted to continue into the future. Revision THA is a technically demanding procedure often complicated by a loss of host bone stock which may be compounded by the need to remove primary implants. Both cemented and uncemented implant designs are commonly used in the United Kingdom for primary and revision THA and much controversy still exists as to the ideal method of stem fixation. In this article we discuss revision of the femur using cemented components during revision THA. We focus on three clinical scenarios including femoral cement-in-cement revision where the primary femoral cement-bone interface remains well fixed, femoral cement-in-cement revision for peri-prosthetic femoral fractures, and femoral impaction grafting. We discuss the clinical indications, surgical techniques and clinical outcomes for each of these procedures.

  1. Revision total hip arthroplasty: the femoral side using cemented implants

    PubMed Central

    Hook, Samantha; Hubble, Matthew

    2010-01-01

    Advances in surgical technique and implant technology have improved the ten-year survival after primary total hip arthroplasty (THA). Despite this, the number of revision procedures has been increasing in recent years, a trend which is predicted to continue into the future. Revision THA is a technically demanding procedure often complicated by a loss of host bone stock which may be compounded by the need to remove primary implants. Both cemented and uncemented implant designs are commonly used in the United Kingdom for primary and revision THA and much controversy still exists as to the ideal method of stem fixation. In this article we discuss revision of the femur using cemented components during revision THA. We focus on three clinical scenarios including femoral cement-in-cement revision where the primary femoral cement-bone interface remains well fixed, femoral cement-in-cement revision for peri-prosthetic femoral fractures, and femoral impaction grafting. We discuss the clinical indications, surgical techniques and clinical outcomes for each of these procedures. PMID:21165618

  2. Impaction allograft with cement for the revision of the femoral component. A minimum 39-month follow-up study with the use of the Exeter stem in Asian hips

    PubMed Central

    Kim, Min-Young; Suh, Yoo-Sung

    2006-01-01

    We report the results of impaction bone grafting of the femoral side in revision total hip arthroplasty in Asian hips (South Korean patients) in which the surgery was performed with the use of the Exeter stem. The minimum follow-up was 39 months (mean, 48.4; range, 39–66). There was subsidence of the cement-graft interface (<1 mm) in three hips (5%), of the stem-cement interface (<1 mm) in 12 hips (21%) and of the stem-cement interface (1–2 mm) in 14 hips (25%). Five hips (9%) developed intraoperative femoral fracture and two hips (4%) femoral perforation in revision. The complications of femoral fracture and subsidence did not have an adverse effect on the final clinical outcomes. The impaction of fresh-frozen allograft and use of a cemented, polished, tapered stem (Exeter stem) were also successful with good clinical and radiographic outcomes in our study of Asian hips (South Korean patients). However, we used smaller stems than the usual ones used for Western patients because of the smaller femur sizes. PMID:16964487

  3. A critical assessment of proximal macrotexturing on cemented femoral components.

    PubMed

    Duffy, G P; Muratoglu, O K; Biggs, S A; Larson, S L; Lozynsky, A J; Harris, W H

    2001-12-01

    We analyzed the cement-metal interface of 3 different types of femoral components that had proximal macrotexturing after in vitro insertion and after fatigue testing designed to produce debonding and micromotion. These components were compared with clinical retrieval specimens. The cement did not flow into the macrotexturing; rather, hollow, brittle volcanoes or calderas were formed. These fragile protrusions of cement become worn down or abraded by debonded components. This abrasion of cement may contribute to the early and aggressive osteolysis seen in some of these early failures with proximal macrotextured components. The formation of these volcanos and calderas can be aborted by placing bone-cement onto the macrotexturing before stem insertion. This simple technique allows the macrotexturing to be filled with cement.

  4. Femoral cement within cement technique in carefully selected aseptic revision arthroplasties.

    PubMed

    Marcos, Lucas; Buttaro, Martin; Comba, Fernando; Piccaluga, Francisco

    2009-06-01

    The aim of this study was to evaluate the clinical and radiological results in a group of patients who underwent aseptic revision hip arthroplasty using the cement within cement (CWC) technique. Between 1999 and 2005, 37 aseptic revision hip operations were performed. There were 30 women and five men, with an average age of 68 years. The reasons for revision were femoral stem fracture, cup failure, acetabular protrusion after hemi-arthroplasty and recurrent dislocation. At an average follow-up of 46 months, none of the patients required further femoral revision. The average post-operative Merle D'Aubigne score was 16.6 points (p<0.05). No evidence of radiological stem failure was observed and no femoral component was considered to be at risk for loosening. In this series of patients, the CWC technique provided consistent with high functional outcomes. This valid and effective alternative should be considered in carefully selected aseptic cases.

  5. The effect of low-viscosity cement on mantle morphology and femoral stem micromotion: a cadaver model with simulated blood flow.

    PubMed

    Race, Amos; Miller, Mark A; Clarke, Michael T; Mann, Kenneth A; Higham, Paul A

    2006-08-01

    Limited data exist on the performance of low-viscosity cement in clinically realistic cadaver models. Paired stem/cement/femur constructs were generated with low-viscosity and standard-viscosity cements. The constructs were created and tested under simulated in vivo conditions, for which novel techniques were developed during this study. Mantle function was quantified by stem/cortex micromotions over 105cycles of "stair-climbing". Mantle morphology was determined from transverse sections. Penetration of low-viscosity cement was greater proximally but less distally (p = 0.02). Low-viscosity cement resulted in more stem retroversion (p = 0.04), but there was no difference in subsidence (p = 0.4). Low-viscosity cement mantles had greater fractions of non-apposed interface (p = 0.006). Fraction of non-apposed interface predicted stem retroversion (R2 = 0.64, p = 0.002). Low-viscosity cement resulted in inferior cement mantles. Early micromotion was reduced by better interface apposition. The greater stem retroversion of low-viscosity cement would probably lead to higher revision rates. Early stem migration is due to interface non-apposition. Techniques should be developed to reduce non-apposition of cemented interfaces.

  6. Effects of distal femoral centralizers on bone-cement in total hip arthroplasty. An experimental analysis of cement-centralizer bonding, cement void formation, and crack propagation.

    PubMed

    Smith, S G; Kabo, J M; Kilgus, D J

    1996-09-01

    Distal femoral centralizers of five different designs were inserted into model femoral stems and cemented into closed-ended tubes simulating a proximal femoral canal. Specimens underwent cyclic loading from 50 to 500 lb. for 0, 1, 2, 5, and 10 million cycles. Each specimen was then sectioned transversely at multiple levels to obtain serial cross-sections, beginning at the femoral stem tip and proceeding distally so as to include the full extent of the centralizer. The area of each section occupied by a centralizer and the total amount of porosity present in the cement surrounding the centralizers were measured using an image analyzer. A dye penetrant was then applied to each section to visualize cement cracks and areas of incomplete bonding between cement and centralizers. The number, length, and location of cement cracks were catalogued for each section. No cement cracks or lack of bonding was observed at the interface between cement and centralizers. There was greater porosity in the specimens containing centralizers than in controls without centralizers (P < .05). The cement surrounding two of the centralizer designs had a significantly smaller amount of porosity than the cement surrounding the other three designs (P < .05). The number of cracks did not depend on whether a centralizer was used, the type of centralizer, or the cycling duration. In the control specimens, failure to adequately plug the centralizer receptacle hole in the stem tip resulted in very large cement voids.

  7. Simplified extraction of broken femoral stems. A brief technical note.

    PubMed

    Kozinn, S C

    1989-01-01

    A simple and inexpensive technique for extracting the retained distal portion of broken femoral stems is described. After removing the loose prosthetic head fragment and surrounding cement, needle-nosed pliers are used to grab the edges of the exposed distal stem. A vise-grip locking wrench is then applied tightly to the pliers to allow axial extraction with mallet blows.

  8. Optimization of a Functionally Graded Material Stem in the Femoral Component of a Cemented Hip Arthroplasty: Influence of Dimensionality of FGM.

    PubMed

    Ait Moussa, Abdellah; Yadav, Rohan

    2017-01-01

    The longevity of hip prostheses is contingent on the stability of the implant within the cavity of the femur bone. The cemented fixation was mostly adopted owing to offering the immediate stability from cement-stem and cement-bone bonding interfaces after implant surgery. Yet cement damage and stress shielding of the bone were proven to adversely affect the lifelong stability of the implant, especially among younger subjects who tend to have an active lifestyle. The geometry and material distribution of the implant can be optimized more efficiently with a three-dimensional realistic design of a functionally graded material (FGM). We report an efficient numerical technique for achieving this objective, for maximum performance stress shielding and the rate of early accumulation of cement damage were concurrently minimized. Results indicated less stress shielding and similar cement damage rates with a 2D-FGM implant compared to 1D-FGM and Titanium alloy implants.

  9. Cement-in-cement revision for selected Vancouver Type B1 femoral periprosthetic fractures: a biomechanical analysis.

    PubMed

    Brew, Christopher J; Wilson, Lance J; Whitehouse, Sarah L; Hubble, Matthew J W; Crawford, Ross W

    2013-03-01

    The aim of this study was to perform a biomechanical analysis of the cement-in-cement (c-in-c) technique for fixation of selected Vancouver Type B1 femoral periprosthetic fractures and to assess the degree of cement interposition at the fracture site. Six embalmed cadaveric femora were implanted with a cemented femoral stem. Vancouver Type B1 fractures were created by applying a combined axial and rotational load to failure. The femora were repaired using the c-in-c technique and reloaded to failure. The mean primary fracture torque was 117 Nm (SD 16.6, range 89-133). The mean revision fracture torque was 50 Nm (SD 16.6, range 29-74), which is above the torque previously observed for activities of daily living. Cement interposition at the fracture site was found to be minimal.

  10. Shortening cemented femoral implants: an in vitro investigation to quantify exeter femoral implant rotational stability vs simulated implant length.

    PubMed

    Wilson, Lance J; Roe, John A; Pearcy, Mark J; Crawford, Ross W

    2012-06-01

    The Exeter stems vary in length from 90 to 150 mm. The shorter stems generally have lower offsets. The purpose of this study was to determine if length of stem, with fixed offset, affected rotational stability. Mechanical testing was carried out on 10 implant-cement constructs with 2 loading profiles, rising from chair and stair climbing, at different simulated implant lengths using purpose-built apparatus. This paper presents a mechanism for clinically observed rotational stability and explains the mechanical characteristics required for rotational stability in Exeter femoral stems.

  11. Contemporary total hip arthroplasty with and without cement in patients with osteonecrosis of the femoral head.

    PubMed

    Kim, Young-Hoo; Oh, S-H; Kim, J-S; Koo, K-H

    2003-04-01

    The rate of failure of primary total hip arthroplasty in patients with osteonecrosis of the femoral head is higher than that in patients with osteoarthritis. The purpose of this prospective study was to document the clinical and radiographic results of arthroplasty with so-called third-generation cementing and the results of second-generation cementless total hip arthroplasty in ninety-eight consecutive patients with osteonecrosis of the femoral head. Fifty patients who had had simultaneous bilateral total hip arthroplasty with a cemented stem in one hip and a cementless stem in the other and forty-eight patients who had had a unilateral total hip arthroplasty with a cementless stem were included in the study. A cementless acetabular component was used in all hips. The presumed cause of the osteonecrosis was ethanol abuse in fifty-seven patients, unknown in twenty-seven, fracture of the femoral neck in nine, and steroid use in five. There were eighty men and eighteen women. The mean age at the time of the arthroplasty was 47.3 years (range, twenty-six to fifty-eight years). Clinical and radiographic evaluations were performed preoperatively; at six weeks; at three, six, and twelve months; and yearly thereafter. The average duration of follow-up was 9.3 years. The average Harris hip scores in the group treated with unilateral arthroplasty (97 points) and the group treated with bilateral arthroplasty (94 points) were similar at the time of final follow-up. They were also similar between the group treated with cement (mean, 96 points) and that treated without cement (95 points). No component had aseptic loosening in either group. In one hip, a cemented femoral stem (2%) and a cementless cup were revised because of infection. Two cementless stems (2%) were revised because of fracture of the proximal part of the femur with loosening of the stem. Annual wear of the polyethylene liner averaged 0.22 mm in the group treated with cement (a zirconia head) and 0.14 mm in the

  12. Femoral impaction bone allografting with an Exeter cemented collarless, polished, tapered stem in revision hip replacement: a mean follow-up of 10.5 years.

    PubMed

    Wraighte, P J; Howard, P W

    2008-08-01

    Femoral impaction bone allografting has been developed as a means of restoring bone stock in revision total hip replacement. We report the results of 75 consecutive patients (75 hips) with a mean age of 68 years (35 to 87) who underwent impaction grafting using the Exeter collarless, polished, tapered femoral stem between 1992 and 1998. The mean follow-up period was 10.5 years (6.3 to 14.1). The median pre-operative bone defect score was 3 (interquartile range (IQR) 2 to 3) using the Endo-Klinik classification. The median subsidence at one year post-operatively was 2 mm (IQR 1 to 3). At the final review the median Harris hip score was 80.6 (IQR 67.6 to 88.9) and the median subsidence 2 mm (IQR 1 to 4). Incorporation of the allograft into trabecular bone and secondary remodelling were noted radiologically at the final follow-up in 87% (393 of 452 zones) and 40% (181 of 452 zones), respectively. Subsidence of the Exeter stem correlated with the pre-operative Endo-Klinik bone loss score (p = 0.037). The degree of subsidence at one year had a strong association with long-term subsidence (p < 0.001). There was a significant correlation between previous revision surgery and a poor Harris Hip score (p = 0.028), and those who had undergone previous revision surgery for infection had a higher risk of complications (p = 0.048). Survivorship at 10.5 years with any further femoral operation as the end-point was 92% (95% confidence interval 82 to 97).

  13. An evaluation of Trapezoidal-28 femoral stem fractures.

    PubMed

    Ritter, M A; Campbell, E D

    1986-11-01

    Fourteen patients sustaining femoral stem fractures of cold rolled wrought stainless steel Trapezoidal-28 prostheses (Zimmir, Warsaw, Indiana) were compared statistically with 259 successful hip replacements of the same type of prosthesis to determine possible factors predisposing to prosthetic fracture. Varus alignment was the highest contributing factor in these femoral stem fractures. Calcar resorption and insufficient distal lateral cement support also were contributory. Medial cement support was less for patients sustaining a fracture, but this was not statistically significant. Patients prone to encounter a fracture were men who were young and/or overweight. There was no significant correlation of fracture to preoperative diagnosis, laterality, trochanteric osteotomy, nonunion of the greater trochanter, or wire breakage.

  14. Mechanisms of stem subsidence in femoral impaction allografting.

    PubMed

    Albert, Carolyne; Frei, Hanspeter; Duncan, Clive; Fernlund, Goran

    2011-01-01

    Failure of the femoral component of total hip arthroplasty is often accompanied by bone loss that can pose a significant challenge to the orthopaedic surgeon. Femoral impaction allografting has attractive potential for restoring bone stock in deficient femurs. However, there have been reports of problematic postoperative stem subsidence with this procedure. Subsidence is highly variable among patients, and there is disagreement over the mechanisms that cause it. This article reviews the various mechanisms that can contribute to subsidence in femoral impaction allografting. Variables such as graft density, cement penetration profile, use of synthetic graft substitutes, or other graft additives are discussed, as well as their potential impact on subsidence. Finally, recommendations are made for future studies aiming to reduce the risk of excessive subsidence in femoral impaction allografting.

  15. Functional interface micromechanics of 11 en-bloc retrieved cemented femoral hip replacements

    PubMed Central

    Miller, Mark A; Verdonschot, Nico; Izant, Timothy H; Race, Amos

    2010-01-01

    Background and purpose Despite the longstanding use of micromotion as a measure of implant stability, direct measurement of the micromechanics of implant/bone interfaces from en bloc human retrievals has not been performed. The purpose of this study was to determine the stem-cement and cement-bone micromechanics of functionally loaded, en-bloc retrieved, cemented femoral hip components. Methods 11 fresh frozen proximal femurs with cemented implants were retrieved at autopsy. Specimens were sectioned transversely into 10-mm slabs and fixed to a loading device where functional torsional loads were applied to the stem. A digital image correlation technique was used to document micromotions at stem-cement and cement-bone interfaces during loading. Results There was a wide range of responses with stem-cement micromotions ranging from 0.0006 mm to 0.83 mm (mean 0.17 mm, SD 0.29) and cement-bone micromotions ranging from 0.0022 mm to 0.73 mm (mean 0.092 mm, SD 0.22). There was a strong (linear-log) inverse correlation between apposition fraction and micromotion at the stem-cement interface (r2 = 0.71, p < 0.001). There was a strong inverse log-log correlation between apposition fraction at the cement-bone interface and micromotion (r2 = 0.85, p < 0.001). Components that were radiographically well-fixed had a relatively narrow range of micromotions at the stem-cement (0.0006–0.057 mm) and cement-bone (0.0022–0.029 mm) interfaces. Interpretatation Minimizing gaps at the stem-cement interface and encouraging bony apposition at the cement-bone interface would be clinically desirable. The cement-bone interface does not act as a bonded interface in actual use, even in radiographically well-fixed components. Rather, the interface is quite compliant, with sliding and opening motions between the cement and bone surfaces. PMID:20367421

  16. In vivo surface wear mechanisms of femoral components of cemented total hip arthroplasties: the influence of wear mechanism on clinical outcome.

    PubMed

    Howell, J R; Blunt, L A; Doyle, C; Hooper, R M; Lee, A J C; Ling, R S M

    2004-01-01

    The appearance and mechanism of femoral stem wear was studied in 172 retrieved femoral components, of which 74 stems had been stable in vivo. Macroscopic, microscopic, and nano-level scales of examination were used. Loss of stem surface in response to micromotion (wear) was found to affect 93% of stems. However, changes were frequently difficult to see with the naked eye, and in 19% of cases they would have been missed completely without the use of light microscopy. The surface finish of the prosthesis determined the mechanism of stem wear. Matte surfaces showed typical abrasive processes that also damage the cement, releasing particulate debris from the cement and metal surfaces. This may destabilize the stem within the cement. Polished stems showed a typical fretting appearance with retention of debris on the stem surface and without significant damage to the cement. These differences in wear mechanism between matte and polished stems have significant effects on stem function.

  17. Femoral cement extraction in revision total hip arthroplasty--an in vitro study comparing computer-assisted freehand-navigated cement removal to conventional cement extraction.

    PubMed

    Mumme, Torsten; Friedrich, Max Julian; Rode, Henrik; Gravius, Sascha; Andereya, Stefan; Müller-Rath, Ralf; de la Fuente, Matias

    2015-12-01

    Revision surgery of cemented femoral stems in total hip arthroplasty is gaining more and more importance, but cement removal in revision hip arthroplasty may be technically challenging. Conventional manual cement removal can be time consuming and be associated with complications such as cortical perforation, fracture, or bone loss. The aim of this study was to investigate the practicability of computer-navigated cement removal. In an in vitro study, we examined the removal of the bone cement out of composite bones. To evaluate accuracy, the bones were scanned before and after cement removal with the ISO-C three-dimensional C-arm computed tomography system to determine the amount of unremoved cement and the loss of bone stock. The data of freehand-navigated cement removal is compared to conventionally extracted cement using levers and drills under X-ray control. The mean time for cement removal was 29 ± 5 min for the conventional method and 32 ± 8 min for the freehand-navigated cement removal. Here, excepting the preparatory examinations, the navigated cement removal only took 13 ± 5 min. The measured temperature during polymerization was 36 ± 5 °C and during navigated cement removal was 37 ± 8 °C. In the distal part of the femur, cement removal was more accurate with the conventional method compared to the navigated one. The freehand-navigated cement removal, with the exception of the preparatory examinations, is time saving compared to the conventional method. However, a potential for technical development especially for the milling device and accuracy exist.

  18. Using “Sub-cement” to simulate the long-term fatigue response of cemented femoral stems in a cadaver model: could a novel pre-clinical screening test have caught the Exeter matte problem?

    PubMed Central

    Race, Amos; Miller, Mark A.; Mann, Kenneth A.

    2010-01-01

    Previously, we formulated cement with degraded fatigue properties (sub-cement) to simulate long-term fatigue in short-term cadaver tests. The present study determined the efficacy of sub-cement in a `pre-clinical' test of a design change with known clinical consequences: the “polished” to “matte” transition of the Exeter stem (revision rates were twice as high for matte stems). Contemporary stems were bead-blasted to give Ra=1micron (matte finish). Matte and polished stems were compared in cadaver pairs under stair-climbing loads (3 pairs size-1, 3 pairs size-3). Stem micromotion was monitored during loading. Post-test, transverse sections were examined for cement damage. Cyclic retroversion decreased for polished stems but increased for matte stems (p<0.0001). Implant size had a substantial effect: retroversion of (larger) size-3 stems was half that of size-1 stems and polished size-3 stems subsided 2½ times more than the others. Cement damage measures were similar and open through-cracks occurred around both stems of two pairs. Stem retroversion within the mantle resulted in stem-cement gaps of 50–150microns. Combining information on cyclic motion, cracks, and gaps, we concluded that this test `predicted' higher revision rates for matte stems (it also implied that polished size-3 stems might be superior to size-1). PMID:20476506

  19. [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

  20. A modified technique to extract fractured femoral stem in revision total hip arthroplasty: A report of two cases

    PubMed Central

    Akrawi, Hawar; Magra, Merzesh; Shetty, Ajit; Ng, Aaron

    2014-01-01

    INTRODUCTION The removal of well-fixed broken femoral component and cement mantle can be extremely demanding, time consuming and potentially damaging to the host bone. Different methods have been described to extract broken femoral stem yet this remains one of the most challenging prospect to the revision hip surgeon. PRESENTATION OF CASE The authors present two cases underwent a modified sliding cortical window technique utilising a tungsten carbide drill, Charnley pin retractor and an orthopaedic mallet to aid extraction of a fractured cemented femoral stem in revision total hip arthroplasty. DISCUSSION The modified technique offers a simple and controlled method in extracting a well fixed fractured cemented femoral stem. It has the advantage of retaining the cement mantle with subsequent good seal of the femoral cortical window secured with cable ready system. Furthermore, tungsten carbide drill bit and Charnley pin retractor are relatively readily available to aid the extraction of the broken stem. Finally, it yields the option of implanting a standard femoral stem and obviates the need for bypassing the cortical window with long revision femoral component. CONCLUSION Fractured femoral stem is a rare yet a complex and very demanding prospect to both patients and hip surgeons. The sliding cortical window technique utilising tungsten carbide drill and Charnley pin retractor is technically easy and most importantly; preserves host bone stock with cement-in-cement revision hip arthroplasty. We believe this technique can be added to the armamentarium of revision hip surgeon when faced with the challenge of extracting a fractured cemented femoral stem. PMID:24858980

  1. Cemented versus uncemented hemiarthroplasty for displaced femoral neck fractures.

    PubMed

    Figved, Wender; Opland, Vidar; Frihagen, Frede; Jervidalo, Tore; Madsen, Jan Erik; Nordsletten, Lars

    2009-09-01

    Hemiarthroplasty is the most commonly used treatment for displaced femoral neck fractures in the elderly. There is limited evidence in the literature of improved functional outcome with cemented implants, although serious cement-related complications have been reported. We performed a randomized, controlled trial in patients 70 years and older comparing a cemented implant (112 hips) with an uncemented, hydroxyapatite-coated implant (108 hips), both with a bipolar head. The mean Harris hip score showed equivalence between the groups, with 70.9 in the cemented group and 72.1 in the uncemented group after 3 months (mean difference, 1.2) and 78.9 and 79.8 after 12 months (mean difference, 0.9). In the uncemented group, the mean duration of surgery was 12.4 minutes shorter and the mean intraoperative blood loss was 89 mL less. The Barthel Index and EQ-5D scores did not show any differences between the groups. The rates of complications and mortality were similar between groups. Both arthroplasties may be used with good results after displaced femoral neck fractures.

  2. Cemented versus Uncemented Hemiarthroplasty for Displaced Femoral Neck Fractures

    PubMed Central

    Opland, Vidar; Frihagen, Frede; Jervidalo, Tore; Madsen, Jan Erik; Nordsletten, Lars

    2009-01-01

    Hemiarthroplasty is the most commonly used treatment for displaced femoral neck fractures in the elderly. There is limited evidence in the literature of improved functional outcome with cemented implants, although serious cement-related complications have been reported. We performed a randomized, controlled trial in patients 70 years and older comparing a cemented implant (112 hips) with an uncemented, hydroxyapatite-coated implant (108 hips), both with a bipolar head. The mean Harris hip score showed equivalence between the groups, with 70.9 in the cemented group and 72.1 in the uncemented group after 3 months (mean difference, 1.2) and 78.9 and 79.8 after 12 months (mean difference, 0.9). In the uncemented group, the mean duration of surgery was 12.4 minutes shorter and the mean intraoperative blood loss was 89 mL less. The Barthel Index and EQ-5D scores did not show any differences between the groups. The rates of complications and mortality were similar between groups. Both arthroplasties may be used with good results after displaced femoral neck fractures. Level of Evidence: Level I, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:19130162

  3. Bone creep and short and long term subsidence after cemented stem total hip arthroplasty (THA).

    PubMed

    Norman, T L; Shultz, T; Noble, G; Gruen, T A; Blaha, J D

    2013-03-15

    Stem-cement and cement-bone interfacial failures as well as cement fractures have been noted in cemented total hip arthroplasty (THA) as the cause of aseptic loosening. Attempts to reduce the risk of femoral component loosening include improving the stem-cement interface by various coatings, using a textured or porous coated stem surfaces or by using a tapered stem having a highly-polished surface. The latter approach, often referred to as "force-closed" femoral stem design, would theoretically result in stem stabilization subsequent to debonding and 'taper-lock'. Previous work using three-dimensional finite element analysis has shown a state of stress at the stem-cement interface indicative of 'taper-lock' for the debonded stem and indicated that stem-cement interface friction and bone cement creep played a significant role in the magnitudes of stresses and subsidence of the stem. However, the previous analysis did not include the viscoelastic properties of bone, which has been hypothesized to permit additional expansion of the bone canal and allow additional stem subsidence (Lu and McKellop, 1997). The goal of this study was to investigate the effect of bone viscoelastic behavior on stem subsidence using a 3D finite element analysis. It was hypothesized that the viscoelastic behavior of bone in the hoop direction would allow expansion of the bone reducing the constraint on bone over time and permit additional stem subsidence, which may account for the discrepancies between predicted and clinical subsidence measurements. Analyses were conducted using physiological loads, 'average peak loads' and 'high peak loads' for 'normal patient' and 'active patient' (Bergmann et al., 2010) from which short and long term subsidence was predicted. Results indicated that bone creep does contribute to higher stem subsidence initially and after 10 years of simulated loading. However, it was concluded that the "constraint" upon the cement mantle is not mitigated enough to result in

  4. The effect of vacuum mixing and pre-heating the femoral component on the mechanical properties of the cement mantle.

    PubMed

    Baleani, M; Bialoblocka-Juszczyk, E; Engels, G E; Viceconti, M

    2010-03-01

    We investigated the effect of pre-heating a femoral component on the porosity and strength of bone cement, with or without vacuum mixing used for total hip replacement. Cement mantles were moulded in a manner simulating clinical practice for cemented hip replacement. During polymerisation, the temperature was monitored. Specimens of cement extracted from the mantles underwent bending or fatigue tests, and were examined for porosity. Pre-heating the stem alone significantly increased the mean temperature values measured within the mantle (+14.2 degrees C) (p < 0.001) and reduced the mean curing time (-1.5 min) (p < 0.001). The addition of vacuum mixing modulated the mean rise in the temperature of polymerisation to 11 degrees C and reduced the mean duration of the process by one minute and 50 seconds (p = 0.01 and p < 0.001, respectively). In all cases, the maximum temperature values measured in the mould simulating the femur were < 50 degrees C. The mixing technique and pre-heating the stem slightly increased the static mechanical strength of bone cement. However, the fatigue life of the cement was improved by both vacuum mixing and pre-heating the stem, but was most marked (+ 280 degrees C) when these methods were combined. Pre-heating the stem appears to be an effective way of improving the quality of the cement mantle, which might enhance the long-term performance of bone cement, especially when combined with vacuum mixing.

  5. Distal femoral physeal growth arrest secondary to a cemented proximal femoral endoprosthetic replacement.

    PubMed

    Gaston, C L; Tillman, R M; Grimer, R J

    2011-05-01

    We report a case of spontaneous physeal growth arrest of the distal femur in a nine-year-old child with Ewing's sarcoma of the proximal femur treated with chemotherapy and endoprosthetic replacement. Owing to the extent of disuse osteoporosis at the time of surgery, the entire intramedullary canal up to the distal femoral physis was filled with cement. Three years later, the femur remained at its pre-operative length of 19 cm. Pre-operative calculations of further growth failed to account for the growth arrest, and the initial expandable growing prosthesis inserted has been revised to a longer one in order to address the leg-length discrepancy. To our knowledge, this is the only reported case of distal femoral physeal growth arrest following cemented endoprosthetic replacement of the proximal femur.

  6. Fatigue fracture of a forged cobalt-chromium-molybdenum femoral component inserted with cement. A report of ten cases.

    PubMed

    Woolson, S T; Milbauer, J P; Bobyn, J D; Yue, S; Maloney, W J

    1997-12-01

    Ten patients who had had a total hip replacement with a forged cobalt-chromium-molybdenum femoral prosthesis (Precoat or Precoat Plus) inserted with cement were seen with a fatigue fracture of the stem an average of fifty months (range, nineteen to seventy-four months) postoperatively. The average age of the patients was sixty-one years (range, forty-three to seventy-three years), and the average weight was ninety-six kilograms (range, seventy to 130 kilograms). Eight patients had had a primary total hip replacement, and two had had a revision; all of the acetabular components had been inserted without cement. Radiographs that had been made before the fracture were available for four of the eight hips that had had a primary replacement; all four had radiographic evidence of debonding of the cement mantle from the proximal end of the stem. This probably caused exaggerated cantilever bending stresses on the proximal aspect of the stem as the distal end of the stem was well fixed. The radiographs of both hips that had had a revision demonstrated a non-union of the greater trochanter, which had resulted in separation at the cement-bone interface at the proximal portion of the femur before the fracture. Scanning electron micrographs of five of the ten fractured prostheses demonstrated a fatigue fracture that began near the anterolateral corner of the prosthesis, through characters that had been etched on the implant with a laser. Metallurgical analysis indicated subsurface voids or inclusions, or both, immediately under the region that had been etched. This finding is consistent with thermal changes to the microstructure of the alloy that probably caused a focal reduction in the material strength. A high proportion (seven) of the ten stems had a poor cement mantle. Also, of the seven small stems that were used, six had been implanted in patients who weighed more than eighty kilograms, so there was relative undersizing of the prostheses. Early debonding of the proximal

  7. Periprosthetic femoral bone loss in total hip arthroplasty: systematic analysis of the effect of stem design.

    PubMed

    Knutsen, Ashleen R; Lau, Nicole; Longjohn, Donald B; Ebramzadeh, Edward; Sangiorgio, Sophia N

    2017-02-21

    Periprosthetic bone loss may lead to major complications in total hip arthroplasty (THA), including loosening, migration, and even fracture. This study analysed the influence of femoral implant designs on periprosthetic bone mineral density (BMD) after THA. The results of all previous published studies reporting periprosthetic femoral BMD following THA were compiled. Using these results, we compared percent changes in bone loss as a function of: femoral stem fixation, material, and geometry. The greatest bone loss was in the calcar region (Gruen Zone 7). Overall, cemented stems had more bone loss distally than noncemented stems, while noncemented stems had more proximal bone loss than cemented stems. Within noncemented stems, cobalt-chromium (CoCr) stems had nearly double the proximal bone loss compared to titanium (Ti) alloy stems. Finally, within noncemented titanium alloy group, straight stems had less bone loss than anatomical, tapered, and press-fit designs. The findings from the present study quantified percent changes in periprosthetic BMD as a function of fixation method, alloy, and stem design. While no one stem type was identified as ideal, we now have a clearer understanding of the influence of stem design on load transfer to the surrounding bone.

  8. Cemented versus uncemented arthroplasty in patients with a displaced fracture of the femoral neck: a randomised controlled trial.

    PubMed

    Inngul, C; Blomfeldt, R; Ponzer, S; Enocson, A

    2015-11-01

    The aim of this randomised controlled study was to compare functional and radiological outcomes between modern cemented and uncemented hydroxyapatite coated stems after one year in patients treated surgically for a fracture of the femoral neck. A total of 141 patients aged > 65 years were included. Patients were randomised to be treated with a cemented Exeter stem or an uncemented Bimetric stem. The patients were reviewed at four and 12 months. The cemented group performed better than the uncemented group for the Harris hip score (78 vs 70.7, p = 0.004) at four months and for the Short Musculoskeletal Function Assesment Questionnaire dysfunction score at four (29.8 vs 39.2, p = 0.007) and 12 months (22.3 vs 34.9, p = 0.001). The mean EQ-5D index score was better in the cemented group at four (0.68 vs 0.53, p = 0.001) and 12 months (0.75 vs 0.58, p = < 0.001) follow-up. There were nine intra-operative fractures in the uncemented group and none in the cemented group. In conclusion, our data do not support the use of an uncemented hydroxyapatite coated stem for the treatment of displaced fractures of the femoral neck in the elderly.

  9. Uncemented revision stem for biological osteosynthesis in periprosthetic femoral fractures.

    PubMed

    Eingartner, C; Volkmann, R; Pütz, M; Weller, S

    1997-01-01

    Fractures around a femoral prosthesis have been treated with plating and additional cement, but this leads to further reduction of bone stock in the proximal femur. Since February 1992, we have dealt with this problem in 12 patients by revision using a long uncemented stem and distal interlocking combined with homologous bone grafting. Bony ingrowth and remodelling led to restoration of the proximal femur. After bone healing, removal of the distal interlocking screws converts the distal load transfer to the proximal anchoring of the revision stem so that osteointegration can occur in the trochanteric region. The clinical results were good in all the patients after a mean follow up of 23.5 months. This is a method which provides biological osteosynthesis and is especially indicated in younger patients.

  10. Fixation of the fully hydroxyapatite-coated Corail stem implanted due to femoral neck fracture

    PubMed Central

    2012-01-01

    Background Today, dislocated femoral neck fractures are commonly treated with a cemented hip arthroplasty. However, cementing of the femoral component may lead to adverse effects and even death. Uncemented stems may lower these risks and hydroxyapatite (HA) coating may enhance integration, but prosthetic stability and clinical outcome in patients with osteoporotic bone have not been fully explored. We therefore studied fixation and clinical outcome in patients who had had a femoral neck fracture and who had received a fully HA-coated stem prosthesis. Patients and methods 50 patients with a dislocated femoral neck fracture were operated with the fully HA-coated Corail total or hemiarthroplasty. 38 patients, mean age 81 (70–96) years, were followed for 24 months with conventional radiographs, RSA, DEXA, and for clinical outcome. Results 31 of the 38 implants moved statistically significantly up to 3 months, mainly distally, mean 2.7 mm (max. 20 mm (SD 4.3)), and rotated into retroversion mean 3.3º (–1.8 to 17) (SD 4.3) and then appeared to stabilize. Distal stem migration was more pronounced if the stem was deemed to be too small. There was no correlation between BMD and stem migration. The migration did not result in any clinically adverse effects. Interpretation The fully hydroxyapatite-coated Corail stem migrates during the first 3 months, but clinical outcome appears to be good, without any adverse events. PMID:22112154

  11. Modified femoral pressuriser generates a longer lasting high pressure during cement pressurisation

    PubMed Central

    2011-01-01

    Background The strength of the cement-bone interface in hip arthroplasty is strongly related to cement penetration into the bone. A modified femoral pressuriser has been investigated, designed for closer fitting into the femoral opening to generate higher and more constant cement pressure compared to a commercial (conventional) design. Methods Femoral cementation was performed in 10 Sawbones® models, five using the modified pressuriser and five using a current commercial pressuriser as a control. Pressure during the cementation was recorded at the proximal and distal regions of the femoral implant. The peak pressure and the pressure-time curves were analysed by student's t-test and Two way ANOVA. Results The modified pressuriser showed significantly and substantially longer durations at higher cementation pressures and slightly, although not statistically, higher peak pressures compared to the conventional pressuriser. The modified pressuriser also produced more controlled cement leakage. Conclusion The modified pressuriser generates longer higher pressure durations in the femoral model. This design modification may enhance cement penetration into cancellous bone and could improve femoral cementation. PMID:22004662

  12. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal 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 femoral (hemi-hip) trunnion-bearing... Devices § 888.3380 Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis is a two...

  13. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal 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 femoral (hemi-hip) trunnion-bearing... Devices § 888.3380 Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis is a two...

  14. 21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint femoral (hemi-hip) metal/polymer... § 888.3390 Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis is a...

  15. 21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint femoral (hemi-hip) metal/polymer... § 888.3390 Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis is a...

  16. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal 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 femoral (hemi-hip) trunnion-bearing... Devices § 888.3380 Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis is a...

  17. 21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis. 888.3360 Section 888.3360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... designs which are intended to be fixed to the bone with bone cement (§ 888.3027) as well as designs...

  18. The influence of cement thickness on stem subsidence and cement creep in a collarless polished tapered stem

    PubMed Central

    Takahashi, E.; Tsuda, R.; Numata, Y.; Ichiseki, T.; Fukui, K.; Kawahara, N.

    2017-01-01

    Objectives Favourable results for collarless polished tapered stems have been reported, and cement creep due to taper slip may be a contributing factor. However, the ideal cement thickness around polished stems remains unknown. We investigated the influence of cement thickness on stem subsidence and cement creep. Methods We cemented six collarless polished tapered (CPT) stems (two stems each of small, medium and large sizes) into composite femurs that had been reamed with a large CPT rasp to achieve various thicknesses of the cement mantle. Two or three tantalum balls were implanted in the proximal cement in each femur. A cyclic loading test was then performed for each stem. The migration of the balls was measured three-dimensionally, using a micro-computed tomography (CT) scanner, before and after loading. A digital displacement gauge was positioned at the stem shoulder, and stem subsidence was measured continuously by the gauge. Final stem subsidence was measured at the balls at the end of each stem. Results A strong positive correlation was observed between mean cement thickness and stem subsidence in the CT slices on the balls. In the small stems, the balls moved downward to almost the same extent as the stem. There was a significant negative correlation between cement thickness and the horizontal:downward ratio of ball movement. Conclusion Collarless polished tapered stems with thicker cement mantles resulted in greater subsidence of both stem and cement. This suggests that excessive thickness of the cement mantle may interfere with effective radial cement creep. Cite this article: E. Takahashi, A. Kaneuji, R. Tsuda, Y. Numata, T. Ichiseki, K. Fukui, N. Kawahara. The influence of cement thickness on stem subsidence and cement creep in a collarless polished tapered stem: When are thick cement mantles detrimental? Bone Joint Res 2017;6:–357. DOI: 10.1302/2046-3758.65.BJR-2017-0028.R1. PMID:28566327

  19. Lower reoperation rate for cemented hemiarthroplasty than for uncemented hemiarthroplasty and internal fixation following femoral neck fracture

    PubMed Central

    2013-01-01

    Background and purpose Elderly patients with displaced femoral neck fractures are commonly treated with a hemiarthroplasty (HA), but little is known about the long-term failure of this treatment. We compared reoperation rates for patients aged at least 75 years with displaced femoral neck fractures treated with either internal fixation (IF), cemented HA, or uncemented HA (with or without hydroxyapatite coating), after 12–19 years of follow-up. Methods 4 hospitals with clearly defined guidelines for the treatment of 75+ year-old patients with a displaced femoral neck fracture were included. Cohort 1 (1991–1993) with 180 patients had undergone IF; cohort 2 (1991–1995) with 203 patients had received an uncemented bipolar Ultima HA stem (Austin-Moore); cohort 3 (1991–1995) with 209 patients had received a cemented Charnley-Hastings HA; and cohort 4 (1991–1998) with 158 patients had received an uncemented hydroxyapatite-coated Furlong HA. Data were retrieved from patient files, from the region-based patient administrative system, and from the National Registry of Patients at the end of 2010. We performed survival analysis with adjustment for comorbidity, age, and sex. Results Cemented HA had a reoperation rate (RR) of 5% and was used as reference in the Cox regression analysis, which showed significantly higher hazard ratios (HRs) for IF (HR = 3.8, 95% CI: 1.9–7.5; RR = 18%), uncemented HA (HR = 2.2, CI: 1.1–4.5; RR = 11%) and uncemented hydroxyapatite-coated HA (HR = 3.6, CI: 1.8–7.4; RR = 16%). Interpretation Cemented HA has a superior long-term hip survival rate compared to IF and uncemented HA (with and without hydroxyapatite coating) in patients aged 75 years or more with displaced femoral neck fractures. PMID:23594248

  20. Peripheral blood stem cell transplantation for ischemic femoral head necrosis.

    PubMed

    Song, H-J; Lan, B-Sh; Cheng, B; Zhang, K-F; Yan, H-W; Wang, W-Zh; Gao, Z-Q

    2010-06-01

    Avascular necrosis of the femoral head (ANFH) is a highly mutilating disease. There is no effective way to treat femoral head ischemia. This study was designed to show the curative effects of peripheral blood stem cell transplantation to induce vascular regeneration and improve ischemic femoral head necrosis in rabbits. Twenty New Zealand white rabbits underwent ischemic femoral head necrosis in both hindlimbs using liquid-nitrogen refrigeration. One cohort of rats was intraperitoneally injected with granulocyte-specific colony-stimulating factor (250 microg/kg/d), and control animals received equivalent saline solution. The right side was used as the transplantation group and the left as the control. After separation of peripheral blood, a stem cell suspension was poured into the right femoral artery and saline solution into the left femoral artery. At 4 weeks after peripheral stem cell transplantation, standing ability and activity of the the transplanted right hindlimb were remarkably improved, but there were no obvious changes in the control limbs. The experimental rabbits underwent arteriography of bilateral femoral heads, which indicated increased and thickened blood supply to the transplanted right hindlimb compared with the left control. Peripheral blood stem cell transplantation improved ischemic femoral head necrosis.

  1. Femoral revision with taper stems: results at ten years follow-up.

    PubMed

    Cherubino, Paolo; Fagetti, Alessandro; D'Angelo, Fabio; Surace, Michele Francesco

    2010-10-01

    In the case of extensively damaged meta-diaphyseal femoral bone with cortices thinning and widened femoral canal, tapered stems allow a good primary fixation and early weight-bearing. A retrospective review was conducted to evaluate long-term results of modular revision taper stems implanted from March 1999 to December 2002. Sixty-five consecutive hip revision surgeries were performed, mostly for aseptic loosening (75% of the cases). Femoral bone stock defects were classified according to AAOS's criteria and consisted mainly in type II (cavitary defects, 44.6%) and type III (combined defects, 33.9%). A trochanteric osteotomy was performed in 25 cases (38%) to remove primary implants that were cemented in 35 cases (54%). The mean postoperative follow-up was 109 months (range, 76 to 131 months). Clinical assessment at follow-up showed a significantly improved mean Harris Hip Score from 42 points preoperatively to 81 points postoperatively, while the x-ray examination did show a satisfactory distal integration of the stem in all cases and satisfactory reconstitution of the femoral bone stock in 47% of cases. The average subsidence of the stem at follow-up was less than one millimeter. According to data analysis, a leg-length discrepancy exceeding 15 millimeters caused significantly worse functional outcome and pain.

  2. The influence of cement thickness on stem subsidence and cement creep in a collarless polished tapered stem: When are thick cement mantles detrimental?

    PubMed

    Takahashi, E; Kaneuji, A; Tsuda, R; Numata, Y; Ichiseki, T; Fukui, K; Kawahara, N

    2017-05-01

    Favourable results for collarless polished tapered stems have been reported, and cement creep due to taper slip may be a contributing factor. However, the ideal cement thickness around polished stems remains unknown. We investigated the influence of cement thickness on stem subsidence and cement creep. We cemented six collarless polished tapered (CPT) stems (two stems each of small, medium and large sizes) into composite femurs that had been reamed with a large CPT rasp to achieve various thicknesses of the cement mantle. Two or three tantalum balls were implanted in the proximal cement in each femur. A cyclic loading test was then performed for each stem. The migration of the balls was measured three-dimensionally, using a micro-computed tomography (CT) scanner, before and after loading. A digital displacement gauge was positioned at the stem shoulder, and stem subsidence was measured continuously by the gauge. Final stem subsidence was measured at the balls at the end of each stem. A strong positive correlation was observed between mean cement thickness and stem subsidence in the CT slices on the balls. In the small stems, the balls moved downward to almost the same extent as the stem. There was a significant negative correlation between cement thickness and the horizontal:downward ratio of ball movement. Collarless polished tapered stems with thicker cement mantles resulted in greater subsidence of both stem and cement. This suggests that excessive thickness of the cement mantle may interfere with effective radial cement creep.Cite this article: E. Takahashi, A. Kaneuji, R. Tsuda, Y. Numata, T. Ichiseki, K. Fukui, N. Kawahara. The influence of cement thickness on stem subsidence and cement creep in a collarless polished tapered stem: When are thick cement mantles detrimental? Bone Joint Res 2017;6:-357. DOI: 10.1302/2046-3758.65.BJR-2017-0028.R1. © 2017 Kaneuji et al.

  3. 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

  4. A randomized study on migration of the Spectron EF and the Charnley flanged 40 cemented femoral components using radiostereometric analysis at 2 years

    PubMed Central

    2011-01-01

    Background and purpose We performed a randomized study to determine the migration patterns of the Spectron EF femoral stem and to compare them with those of the Charnley stem, which is regarded by many as the gold standard for comparison of implants due to its extensive documentation. Patients and methods 150 patients with a mean age of 70 years were randomized, single-blinded, to receive either a cemented Charnley flanged 40 monoblock, stainless steel, vaquasheen surface femoral stem with a 22.2-mm head (n = 30) or a cemented Spectron EF modular, matte, straight, collared, cobalt-chrome femoral stem with a 28-mm femoral head and a roughened proximal third of the stem (n = 120). The patients were followed with repeated radiostereometric analysis for 2 years to assess migration. Results At 2 years, stem retroversion was 2.3° and 0.7° (p < 0.001) and posterior translation was 0.44 mm and 0.17 mm (p = 0.002) for the Charnley group (n = 26) and the Spectron EF group (n = 74), respectively. Subsidence was 0.26 mm for the Charnley and 0.20 mm for the Spectron EF (p = 0.5). Interpretation The Spectron EF femoral stem was more stable than the Charnley flanged 40 stem in our study when evaluated at 2 years. In a report from the Norwegian arthroplasty register, the Spectron EF stem had a higher revision rate due to aseptic loosening beyond 5 years than the Charnley. Initial stability is not invariably related to good long-term results. Our results emphasize the importance of prospective long-term follow-up of prosthetic implants in clinical trials and national registries and a stepwise introduction of implants. PMID:21895504

  5. Comparative Study of Bipolar Hemiarthroplasty for Femur Neck Fractures Treated with Cemented versus Cementless Stem

    PubMed Central

    Choi, Jung-Yun; Kim, Joo-Hyung

    2016-01-01

    Purpose To compare and analyze clinical and radiologic outcomes of cemented versus cementless bipolar hemiarthroplasty for treatment of femur neck fractures. Materials and Methods A total of 180 patients aged 65 years and over older who underwent bipolar hemiarthroplasty for treatment of displaced femur neck fractures (Garden stage III, IV) from March 2009 to February 2014 were included in this study. Among the 180 patients, 115 were treated with cemented stems and 65 patients with cementless stems. Clinical outcomes assessed were: i) postoperative ambulatory status, ii) inguinal and thigh pain, and iii) complications. The radiologic outcome was femoral stem subsidence measured using postoperative simple X-ray. Results The cemented group had significantly lower occurrence of complications (postoperative infection, P=0.04) compared to the cementless group. There was no significant difference in postoperative ambulatory status, inguinal and thigh pain, and femoral stem subsidence. Conclusion For patients undergoing bipolar hemiarthroplasty, other than complications, there was no statistically significant difference in clinical or radiologic outcomes in our study. Selective use of cemented stem in bipolar hemiarthroplasty may be a desirable treatment method for patients with poor bone quality and higher risk of infections. PMID:28097110

  6. Porosity reduction in bone cement at the cement-stem interface.

    PubMed

    Bishop, N E; Ferguson, S; Tepic, S

    1996-05-01

    The fatigue failure of bone cement, leading to loosening of the stem, is likely to be one mode of failure of cemented total hip replacements. There is strong evidence that cracks in the cement are initiated at voids which act as stress risers, particularly at the cement-stem interface. The preferential formation of voids at this site results from shrinkage during polymerisation and the initiation of this process at the warmer cement-bone interface, which causes bone cement to shrink away from the stem. A reversal of the direction of polymerisation would shrink the cement on to the stem and reduce or eliminate the formation of voids at this interface. We have investigated this by implanting hip prostheses, at room temperature or preheated to 44 degrees C, into human cadaver femora kept at 37 degrees C. Two types of bone cement were either hand-mixed or vacuum-mixed before implantation. We found that the area of porosity at the cement-stem interface was dramatically reduced by preheating the stem and that the preheating temperature of 44 degrees C determined by computer analysis of transient heat transfer was the minimum required to induce initial polymerisation at the cement-stem interface. Temperature measurements taken during these experiments in vitro showed that preheating of the stem caused a negligible increase in the temperature of the bone. Reduction of porosity at the cement-stem interface could significantly increase the life of hip arthroplasties.

  7. Femoral stem fracture and in vivo corrosion of retrieved modular femoral hips.

    PubMed

    Huot Carlson, J Caitlin; Van Citters, Douglas W; Currier, John H; Bryant, Amber M; Mayor, Michael B; Collier, John P

    2012-08-01

    A series of 78 retrieved modular hip devices were assessed for fretting and corrosion. Damage was common at both the head-neck junction (54% showing corrosion; 88% showing fretting) and at the stem-sleeve junction (88% corrosion; 65% fretting). Corrosion correlated to in vivo duration, patient activity, and metal (vs ceramic) femoral heads but did not correlate to head carbon content. Femoral stem fatigue fracture was observed in seven retrievals; all had severe corrosion, were under increased stress, and were in vivo longer than the non-fractured cohort. This study emphasizes the potential for stem fracture when small diameter femoral stems with large offsets are used in heavy and active patients. Designs which reduce fretting and corrosion in modular implants is warranted as patients demand longer lasting implants.

  8. Development of a femoral stem providing strong anchorage and facilitated removal. An experimental study in goats.

    PubMed

    Harboe, K; Enoksen, C H; Gjerdet, N R; Sudmann, E

    2012-01-01

    Prosthetic elements must be securely anchored to bone. Should revision surgery be necessary, preservation of bone stock is crucial. The goal of this study was to develop and assess a femoral stem combining secure anchorage and facilitated removal in a goat model. The development of the uncemented femoral stem was part of an innovation process to fulfill the combined requirements. The stem was designed with two longitudinal semicircular grooves to accommodate a drill bit to unanchor the stem. These grooves were interconnected by canals, each 1 mm in diameter. The surface was partly coated with hydroxyapatite (HA). The stems were inserted in the left hip of 35 goats. Perioperatively, the grooves were filled with autologous bone grafts, and standard cemented canine acetabular component and head were used. The pull-out force was measured six months postoperatively. Following randomization, 11 animals had the grooves of the stem drilled to remove anchoring tissue. Twelve animals were left undrilled (controls). There was a significant difference in mean pull-out force between the group that had been drilled (1526 N) compared with the controls (2033 N, p = 0.028). Most of the HA had been resorbed. The stems had a high retention force. The procedure for un-anchoring by drilling significantly reduced the pull-out force.

  9. Isolated acetabular revision with femoral stem retention after bipolar hip arthroplasty.

    PubMed

    Kaku, Nobuhiro; Tabata, Tomonori; Tagomori, Hiroaki; Tsumura, Hiroshi

    2017-03-01

    In bipolar hemiarthroplasty, migration of the outer cup component into the acetabular cup, with evidence of severe osteolysis in the acetabulum, commonly occurs without loosening of the femoral component. The merits of retaining the stable femoral component in these cases have been debated. Our study aimed to determine whether revision of the acetabular component in isolation could be successfully performed. The data of 54 patients (61 hips), 44 women, and 10 men, aged 67.7 (range 47-86) years at the time of the index revision, were analyzed. The average time from primary operation to revision surgery was 14.9 (range 1.0-27.0) years, with an average follow-up time after revision of 5.2 (range, 1.0-18.7) years. Indications for acetabular revision included migration of the outer cup component (N = 55), disassembly of the bipolar cup (N = 4), and recurrent dislocation (N = 2). Fixation of the femoral stem was cementless in 49 hips and cemented in 12. Bone grafting for osteolysis of the proximal femur around the stem was performed in six hips. An acetabular reinforcement ring with a cemented cup was used in 31 hips, with cementless cup fixation in 29 hips, and cemented cup in one case. On average, the Harris hip score improved from 57.0 ± 21.6 to 87.4 ± 6.40 points after revision. Two cases of femoral periprosthetic fracture were treated with osteosynthesis 3 year post-revision. There was no evidence of loosening of the femoral stem or subsidence, with a non-progressive radiolucent line <2 mm identified in one case. There was no incidence of dislocation or deep infection, and all components were judged to be stable at the final follow-up. Isolated acetabular revision can be reliably performed in cases of failed bipolar hemiarthroplasty with a well-fixed femoral component.

  10. Fracture of Uncemented Revision Femoral Stems in three Arthroplasty Patients: A Case Series with three different brands

    PubMed Central

    Merchant, Rajiv; Kelly, Ian; Quinlan, John

    2014-01-01

    Introduction: Fracture of stems in primary total hip arthroplasty is a known complication and has been attributed to varus positioning, excessive weight of the patient, resorption of the femoral calcar and failure of the cement mantle. Fractures in uncemented revision femoral stems are rare and are attributed to reduction in proximal support either in the form of bone loss or an extended trochanteric osteotomy [ETO] against a distally well- fixed stem. Also, undersized stems and high BMI to increase the risk of stem fracture. Case Report: We report 3 cases of uncemented revision stem fractures. Case 1 is a 77 year old male, Case 2 is a 71- year-old female, case 3 an 82-year-old male. All three patients had significant proximal femoral osteolysis. All three had an extended trochanteric osteotomy for the revision surgery. The hips had remained in-situ for 4, 2 and 5 years respectively prior to fracture. Conclusion: When planning complex revision cases involving long uncemented stems, attention should be given to the above-mentioned variables. ETO non-union and proximal bone loss play an important role in stem fractures. Stem failure can occur irrespective of the make, and factors such as adequate stem size and good diaphyseal fit are non negotiable. PMID:27298992

  11. Stresses in cement mantles of hip replacements: effect of femoral implant sizes, body mass index and bone quality.

    PubMed

    Lamvohee, J-M S; Mootanah, R; Ingle, P; Cheah, K; Dowell, J K

    2009-10-01

    The effects of femoral prosthetic heads of diameters 22 and 28 mm were investigated on the stability of reconstructed hemi-pelves with cement mantles of thicknesses 1-4 mm and different bone qualities. Materialise medical imaging package and I-Deas finite element (FE) software were used to create accurate geometry of a hemi-pelvis from CT-scan images. Our FE results show an increase in cement mantle stresses associated with the larger femoral head. When a 22 mm femoral head is used on acetabulae of diameters 56 mm and above, the probability of survivorship can be increased by creating a cement mantle of at least 1 mm thick. However, when a 28 mm femoral head is used, a cement mantle thickness of at least 4 mm is needed. Poor bone quality resulted in an average 45% increase in the tensile stresses of the cement mantles, indicating resulting poor survivorship rate.

  12. 21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... designs which are intended to be fixed to the bone with bone cement (§ 888.3027) as well as designs which have large window-like holes in the stem of the device and which are intended for use without bone cement. However, in these latter designs, fixation of the device is not achieved by means of bone...

  13. 21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... designs which are intended to be fixed to the bone with bone cement (§ 888.3027) as well as designs which have large window-like holes in the stem of the device and which are intended for use without bone cement. However, in these latter designs, fixation of the device is not achieved by means of bone...

  14. 21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... designs which are intended to be fixed to the bone with bone cement (§ 888.3027) as well as designs which have large window-like holes in the stem of the device and which are intended for use without bone cement. However, in these latter designs, fixation of the device is not achieved by means of bone...

  15. 21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... designs which are intended to be fixed to the bone with bone cement (§ 888.3027) as well as designs which have large window-like holes in the stem of the device and which are intended for use without bone cement. However, in these latter designs, fixation of the device is not achieved by means of bone...

  16. Total hip arthroplasty using TRI-LOCK® DePuy bone preservation femoral stem: our experience.

    PubMed

    Sperati, G; Ceri, L

    2014-09-24

    In this study we report our 3-years experience (from January 2010 to December 2013) of 101 total hip arthroplasties using Tri-Lock® DePuy bone preservation femoral stem, all performed in our clinic. 101 patients (F54-M47; median age around 69 yrs, range 42-84 yrs). 51 arthroplasties were implanted on the right side whereas 50 on the left side. The average follow-up was 27,3 months. All the arthroplasties were coupled with Pinnacle® polyethylene acetabular cup system; 98 prostheses were implanted cementless whereas cement was used in 3 cases. The Tri-Lock® femoral stem allows both soft tissues and bone stock preservation, leading to greater trochanter maintenance, less spongy bone removal and distal cavity bone tissue conservation. In our experience, we were able to implant the Tri-Lock® femoral stem even in osteoporotic and overweight patients using Gription® porous coating. This allowed for commencing an intensive rehabilitation program with stable load from the following day, without observing any early complications or loosening. According to us, this device is solid and safe, providing remarkable sparing of both soft tissues and bone stock.

  17. Evaluation of injectable strontium-containing borate bioactive glass cement with enhanced osteogenic capacity in a critical-sized rabbit femoral condyle defect model.

    PubMed

    Zhang, Yadong; Cui, Xu; Zhao, Shichang; Wang, Hui; Rahaman, Mohamed N; Liu, Zhongtang; Huang, Wenhai; Zhang, Changqing

    2015-02-04

    The development of a new generation of injectable bone cements that are bioactive and have enhanced osteogenic capacity for rapid osseointegration is receiving considerable interest. In this study, a novel injectable cement (designated Sr-BBG) composed of strontium-doped borate bioactive glass particles and a chitosan-based bonding phase was prepared and evaluated in vitro and in vivo. The bioactive glass provided the benefits of bioactivity, conversion to hydroxyapatite, and the ability to stimulate osteogenesis, while the chitosan provided a cohesive biocompatible and biodegradable bonding phase. The Sr-BBG cement showed the ability to set in situ (initial setting time = 11.6 ± 1.2 min) and a compressive strength of 19 ± 1 MPa. The Sr-BBG cement enhanced the proliferation and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells in vitro when compared to a similar cement (BBG) composed of chitosan-bonded borate bioactive glass particles without Sr. Microcomputed tomography and histology of critical-sized rabbit femoral condyle defects implanted with the cements showed the osteogenic capacity of the Sr-BBG cement. New bone was observed at different distances from the Sr-BBG implants within eight weeks. The bone-implant contact index was significantly higher for the Sr-BBG implant than it was for the BBG implant. Together, the results indicate that this Sr-BBG cement is a promising implant for healing irregularly shaped bone defects using minimally invasive surgery.

  18. Femoral cement pressurization in hip arthroplasty: a comparison of 3 systems.

    PubMed

    Munro, Niall Alasdair; Nicol, Malcolm; Selvaraj, Sivasubramaniam; Hussain, Sheik Mehboob; Finlayson, David Farquhar

    2007-09-01

    Cement pressurization is critical to achieving optimal results in cemented arthroplasty of the hip. An in vitro experiment using plastic femoral models (10 per group) was undertaken to measure the pressures developed by 3 cementing systems: the Howmedica Mark 1 (Stryker Howmedica, Limerick, Ireland) and DePuy Cemvac retrograde cementation systems (DePuy CMW, Blackpool, UK), and a novel antegrade system consisting of a 60-mL catheter-tipped syringe and a Miller proximal femoral seal (Zimmer Ltd, Swindon, UK). The mean pressure was higher for the syringe system (161.45 +/- 28.9 kPa) than the Mark 1 (103.51 +/- 22.0 kPa) or Cemvac (92.65 +/- 30.7 kPa) systems (P = .0001). In addition, fewer cement mantle defects were seen with the syringe system (1, interquartile range [IQR] 1-2) than the Mark 1 (3, IQR 2-4) or Cemvac (3, IQR 1-3) systems (P = .0256).

  19. Cement in cement revision of the femoral component using a collarless triple taper: a midterm clinical and radiographic assessment.

    PubMed

    Stefanovich-Lawbuary, Natalija S; Parry, Michael C; Whitehouse, Michael R; Blom, Ashley W

    2014-10-01

    This study describes the midterm clinical and radiological results of the cement in cement technique for the femur using a collarless triple taper. Radiographic assessment was made retrospectively from 44 patients at two time points. Clinical outcomes included the Oxford Hip Score, EQ5D and Self Reported Patient Satisfaction Scale. Implant and patient survival were also recorded. The mean clinical follow up period was 5years 3months and the radiological follow up 2years 10months. The mean OHS was 34, the mean EQ5D 0.814 and the mean SAPS 94. Kaplan-Meier survival with revision, as the end point was 95.2% at 11years with a survivorship of 76.5% with death as the end point. Cement in cement revision using a collarless triple tapered stem demonstrates promising results both clinically and radiologically at midterm follow up. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Treatment of periprosthetic femoral fractures with modular stems.

    PubMed

    Hernandez-Vaquero, Daniel; Fernandez-Lombardia, Jesus; de los Rios, Jimena Llorens; Perez-Coto, Ivan; Iglesias-Fernandez, Susana

    2015-10-01

    The purpose of this study was to analyse the efficacy of modular femoral stems for the treatment of certain post-operative periprosthetic fractures in patients with hip arthroplasty. Of a total series of 61 modular revision stems, 17 were used to address periprosthetic femoral fractures and 12 of these are the object of this study. The average follow-up was 3.7 years (range 1-14 years). The evaluations were performed at three and six months, and then annually using the HHS score and radiographic studies for the assessment of loosening, subsidence and bone integration of the stem. Seven cases had type B2 fractures and five type B3 ones. All patients walked freely, eight of them using canes. HHS improved to a post-operative mean of 78 (range 72-83). Radiographically, fracture healing was observed at three months in nine cases. In six cases stem subsidence of a mean of 3.9 mm (range 2-12 mm) was observed, which stabilized a year following implantation and did not need revision surgery. In two cases a subsequent dislocation (at three and seven months after surgery) occurred, which were treated with constrained acetabular systems. In nine cases hypotrophy of the cortex in the diaphyseal area was noted, which did not alter the patients' clinical course. Modular femoral stems are an acceptable treatment in type B2 and B3 periprosthetic fractures.

  1. Revision total hip arthroplasty using cemented collarless double-taper femoral components at a mean follow-up of 13 years (8 to 20): an update.

    PubMed

    Solomon, L B; Costi, K; Kosuge, D; Cordier, T; McGee, M A; Howie, D W

    2015-08-01

    The outcome of 219 revision total hip arthroplasties (THAs) in 98 male and 121 female patients, using 137 long length and 82 standard length cemented collarless double-taper femoral stems in 211 patients, with a mean age of 72 years (30 to 90) and mean follow-up of six years (two to 18) have been described previously. We have extended the follow-up to a mean of 13 years (8 to 20) in this cohort of patients in which the pre-operative bone deficiency Paprosky grading was IIIA or worse in 79% and 73% of femurs with long and standard stems, respectively. For the long stem revision group, survival to re-revision for aseptic loosening at 14 years was 97% (95% confidence interval (CI) 91 to 100) and in patients aged > 70 years, survival was 100%. Two patients (two revisions) were lost to follow-up and 86 patients with 88 revisions had died. Worst-case analysis for survival to re-revision for aseptic loosening at 14 years was 95% (95% CI 89 to 100) and 99% (95% CI 96 to 100) for patients aged > 70 years. One additional long stem was classified as loose radiographically but not revised. For the standard stem revision group, survival to re-revision for aseptic loosening at 14 years was 91% (95% CI 83 to 99). No patients were lost to follow-up and 49 patients with 51 hips had died. No additional stems were classified as loose radiographically. Femoral revision using a cemented collarless double-taper stem, particularly with a long length stem, and in patients aged > 70 years, continues to yield excellent results up to 20 years post-operatively, including in hips with considerable femoral metaphyseal bone loss. ©2015 The British Editorial Society of Bone & Joint Surgery.

  2. Cemented or uncemented hemiarthroplasty for the treatment of femoral neck fractures?

    PubMed Central

    2014-01-01

    Background and purpose Cemented hemiarthroplasty is preferred in treating displaced fractures of the femoral neck in the elderly. The cementing process may cause a fat embolism, leading to serious complications or death. In this study, we wanted to determine whether use of uncemented hemiarthroplasty (HA) would lead to reduced mortality and whether there are differences in the complications associated with these different types of arthroplasty. Patients and methods From the PERFECT database, which combines information from various treatment registries, we identified 25,174 patients who were treated with hemiarthroplasty for a femoral neck fracture in the years 1999–2009. The primary outcome was mortality. Secondary outcomes were reoperations, complications, re-admissions, and treatment times. Results Mortality was lower in the first postoperative days when uncemented HA was used. At 1 week, there was no significant difference in mortality (3.9% for cemented HA and 3.4% for uncemented HA; p = 0.09). This was also true after one year (26% for cemented HA and 27% for uncemented HA; p = 0.1). In patients treated with uncemented HA, there were significantly more mechanical complications (3.7% vs. 2.8%; p < 0.001), hip re-arthroplasties (1.7% vs. 0.95; p < 0.001), and femoral fracture operations (1.2% vs. 0.52%; p < 0.001) during the first 90 days after hip fracture surgery. Interpretation From registry data, mortality appears to be similar for cemented and uncemented HA. However, uncemented HA is associated with more frequent mechanical complications and reoperations. PMID:24397746

  3. Wear and migration of highly cross-linked and conventional cemented polyethylene cups with cobalt chrome or Oxinium femoral heads: a randomized radiostereometric study of 150 patients.

    PubMed

    Kadar, Thomas; Hallan, Geir; Aamodt, Arild; Indrekvam, Kari; Badawy, Mona; Skredderstuen, Arne; Havelin, Leif Ivar; Stokke, Terje; Haugan, Kristin; Espehaug, Birgitte; Furnes, Ove

    2011-08-01

    This randomized study was performed to compare wear and migration of five different cemented total hip joint articulations in 150 patients. The patients received either a Charnley femoral stem with a 22.2 mm head or a Spectron EF femoral stem with a 28 mm head. The Charnley articulated with a γ-sterilized Charnley Ogee acetabular cup. The Spectron EF was used with either EtO-sterilized non-cross-linked polyethylene (Reflection All-Poly) or highly cross-linked (Reflection All-Poly XLPE) cups, combined with either cobalt chrome (CoCr) or Oxinium femoral heads. The patients were followed with repeated RSA measurements for 2 years. After 2 years, the EtO-sterilized non-cross-linked Reflection All-Poly cups had more than four times higher proximal penetration than its highly cross-linked counterpart. Use of Oxinium femoral heads did not affect penetration at 2 years compared to heads made of CoCr. Further follow-up is needed to evaluate the benefits, if any, of Oxinium femoral heads in the clinical setting. The Charnley Ogee was not outperformed by the more recently introduced implants in our study. We conclude that this prostheses still represents a standard against which new implants can be measured. Copyright © 2011 Orthopaedic Research Society.

  4. Application of circular statistics in the study of crack distribution around cemented femoral components.

    PubMed

    Mann, Kenneth A; Gupta, Sameer; Race, Amos; Miller, Mark A; Cleary, Richard J

    2003-08-01

    Cemented stem constructs were loaded in cyclic fatigue using stair climbing loading and the resulting fatigue damage to the cement mantle was determined in terms of angular position of crack and crack length. Techniques from circular statistics were used to determine if the distribution of micro-cracks was uniform. With a designated orientation of 0 degrees -90 degrees -180 degrees -270 degrees indicating lateral-anterior-medial-posterior anatomic directions, the overall distribution of cracks was not uniform (p<0.05) with a mean crack direction in the postero-medial (249 degrees) quadrant of the mantle. The crack angular distribution for proximal (postero-medial; 251 degrees) and distal (antero-medial; 112 degrees) regions of the cement mantle was also different (p<0.025). These findings suggest that the location of cement damage depends on anatomic position and appears to correspond with the tensile stress field in the cement mantle.

  5. Numerical simulation of thermal bone necrosis during cementation of femoral prostheses.

    PubMed

    Mazzullo, S; Paolini, M; Verdi, C

    1991-01-01

    The implant of a femoral prosthesis is a critical process because of the relatively high temperature values reached at the bone/cement interface during the cementation of the infibulum. In fact, the cement is actually a polymer that polymerizes in situ generating heat. Moreover, the conversion of monomer into polymer is never 100%; this is dangerous because of the toxicity of the monomer. In this paper, we present a 3-D axisymmetric mathematical model capable of taking into account both the geometry of the implant and the chemical/physical properties of the cement. This model, together with its numerical simulation, thus represents a useful tool to set up the optimal conditions for the new materials developed in this orthopaedic field. The real complex geometry is assumed to be a bone/cement/metallic system having cylindrical symmetry, thus allowing the model to be reduced to two space variables. The cementation process is described by the Fourier heat equation coupled with a suitable polymerization kinetics. The numerical approximation is accomplished by semi-implicit finite differences in time and finite elements in space with numerical quadrature. The full discrete scheme amounts to solve linear positive definite symmetric systems preceded by an elementwise algebraic computation. We present various numerical simulations which confirm some critical aspects of this orthopaedic fixing technique such as thermal bone necrosis and the presence of unreacted residual monomer.

  6. Does stem preheating have a beneficial effect on PMMA bulk porosity in cemented THA?

    PubMed

    Madrala, A; Nuño, N; Bureau, M N

    2010-10-01

    In cemented total hip arthroplasty (THA), porosity plays a major role in the fatigue failure of bone cement. Stem preheating procedure is known to reduce the stem/cement interfacial porosity. In the literature, no information is available about the effect of such procedure on cement bulk porosity. This study helps to find out if stem preheating can have a beneficial effect on bulk porosity, thus enhancing long-term bone cement integrity. A simplified experimental model of a stem/cement/bone construct of a cemented THA is designed to reproduce the mechanical boundary conditions of polymerizing cement. Effect of stem preheating and polymethylmethacrylate prechilling and mixing method (hand mixed and vacuum mixed) on cement porosity are investigated. Bulk porosity is analysed within three zones across the cement mantle in terms of pore number, pore area, and mean pore size. The results demonstrate that bulk cement porosity is strongly influenced by stem preheating, cement precooling as well as cement composition and mixing method. Stem preheating procedure displaces the porosity away from stem/cement interface toward bone; consequently reducing the pore area within the zone near the stem and increasing it in the middle and bone/cement zone. The most pronounced beneficial effect of stem preheating before implantation is visible for vacuum mixed procedure as the cement contains few pores of very small size (<100 μm). However, if stem is preheated, cement precooling should be avoided as it could counteract the beneficial effect of reduced porosity inside cement mantle.

  7. Range of motion in a modular femoral stem system with a variety of neck options.

    PubMed

    Hariri, Sanaz; Chun, Sungwook; Cowan, James B; Bragdon, Charles; Malchau, Henrik; Rubash, Harry E

    2013-10-01

    Modular femoral stem systems decouple leg length, offset, and version. The hip ROM and type of impingement for 162 femoral head/neck combinations were measured at four extreme hip positions in a Sawbones pelvis and femur to identify constructs that lead to early impingement. Hip ROM increased in all positions with increasing head size and neck length. We identified a new type of impingement created by the build-up of the proximal femoral stem: femoral stem on acetabular liner impingement. Seventy percent of neutral neck options achieved our definition of acceptable ROM. In general, when utilizing a modular femoral stem, surgeons can minimize impingement by choosing the longest femoral neck that does not over-lengthen the limb, using the largest femoral head accommodated by the cup, and avoiding neck version unless the cup or stem is malaligned.

  8. Fixation of the fully hydroxyapatite-coated Corail stem implanted due to femoral neck fracture: 38 patients followed for 2 years with RSA and DEXA.

    PubMed

    Schewelov, Thord von; Ahlborg, Henrik; Sanzén, Lennart; Besjakov, Jack; Carlsson, Ake

    2012-04-01

    Today, dislocated femoral neck fractures are commonly treated with a cemented hip arthroplasty. However, cementing of the femoral component may lead to adverse effects and even death. Uncemented stems may lower these risks and hydroxyapatite (HA) coating may enhance integration, but prosthetic stability and clinical outcome in patients with osteoporotic bone have not been fully explored. We therefore studied fixation and clinical outcome in patients who had had a femoral neck fracture and who had received a fully HA-coated stem prosthesis. 50 patients with a dislocated femoral neck fracture were operated with the fully HA-coated Corail total or hemiarthroplasty. 38 patients, mean age 81 (70-96) years, were followed for 24 months with conventional radiographs, RSA, DEXA, and for clinical outcome. 31 of the 38 implants moved statistically significantly up to 3 months, mainly distally, mean 2.7 mm (max. 20 mm (SD 4.3)), and rotated into retroversion mean 3.3º (-1.8 to 17) (SD 4.3) and then appeared to stabilize. Distal stem migration was more pronounced if the stem was deemed to be too small. There was no correlation between BMD and stem migration. The migration did not result in any clinically adverse effects. The fully hydroxyapatite-coated Corail stem migrates during the first 3 months, but clinical outcome appears to be good, without any adverse events.

  9. Excessive distal migration of fiber-mesh coated femoral stems

    PubMed Central

    2011-01-01

    Background The surface texture, localization, and magnitude of the surface material applied to the femoral stem can facilitate bone ingrowth and influence the survival of total hip arthroplasties. Clinical and radiographic studies have shown superior bone ingrowth in proximally porous-coated stems with a diaphyseal grit-blasted surface in comparison to a smooth diaphyseal surface. Surface textures—especially porous surface material—have been suggested to have a sealing effect against migration of polyethylene debris along the implant-bone interface and to reduce the inflammatory response, leading to a prolonged implant survival. Patients and methods Between 2004 and 2006, we conducted a randomized, controlled trial (RCT) involving 50 patients with non-inflammatory arthritis. They received either a distally tapered, extended coated stem or a straight, proximally coated stem. During surgery, tantalum markers were inserted into the greater and lesser trochanter. Implant migration was evaluated at 3, 12, and 24 months postoperatively by radiostereometric analysis. The primary endpoint was stem migration 2 years after surgery. Results All femoral components in both groups showed pronounced distal translation, with the highest rate of translation occurring between 0 and 3 months. After 2 years, the mean distal translation was 2.67 (95% CI: –3.93 to –1.42) mm for the tapered, extended coated stem and 1.80 (–2.45 to –1.15) mm for the straight, proximally coated stem. Half of the tapered, extended coated stems and two-thirds of the straight, proximally coated stems had migrated more than 1 mm. No difference between the 2 stems could be seen with regard to translation or rotation at any time point. After 2 years, 2 hips have been reoperated due to mechanical loosening of the stem. Interpretation An excessive amount of migration of both stem types was seen 2 years postoperatively. It is of vital importance to follow this patient cohort since radiostereometric

  10. Cemented versus Uncemented Hemiarthroplasty for Femoral Neck Fractures in Elderly Patients: A Meta-Analysis

    PubMed Central

    Weng, Xisheng; Zhou, Lei; Bian, Yanyan

    2013-01-01

    Objective Controversy still exists regarding using cemented or uncemented hemiarthroplasty for femoral neck fractures in elderly patients. The aim of this study is to compare the effectiveness and safety of the two surgical techniques in femoral neck fracture patients over 70 years old. Methods We searched PUBMED, EMBASE, Cochrane Library, CNKI and VIP Database from inception to December 2012 for relevant randomized controlled trials (RCTs). Outcomes of interest include postoperative hip function, residue pain, complication rates, mortality, reoperation rate, operation time and intraoperative blood loss. Odds ratios (OR) and weighted mean differences (WMD) from each trial were pooled using random-effects model or fixed-effects model given on the heterogeneity of the included studies. Results 7 RCTs involving 1,125 patients (1,125 hips) were eligible for meta-analysis. Our results demonstrate that cemented hemiarthroplasty is associated with better postoperative hip function (OR = 0.48, 95% CI, 0.31–0.76; P = 0.002), lower residual pain (OR = 0.43, 95%CI, 0.29–0.64; P<0.0001), less implant-related complications (OR = 0.15, 95%CI, 0.09–0.26; P<0.00001) and longer operation time (WMD = 7.43 min, 95% CI, 5.37–9.49 min; P<0.00001). No significant difference was observed between the two groups in mortality, cardiovascular and cerebrovascular complications, local complications, general complications, reoperation rate and intraoperative blood loss. Conclusions Compared with uncemented hemiarthroplasty, the existing evidence indicates that cemented hemiarthroplasty can achieve better hip function, lower residual pain and less implant-related complications with no increased risk of mortality, cardiovascular and cerebrovascular complications, general complications, local complications and reoperation rate in treating elderly patients with femoral neck fractures. PMID:23935902

  11. Temporary total hip arthroplasty-like spacer for treating an infected periprosthetic femoral fracture using a long stem: A case report.

    PubMed

    Kim, Youngwoo; Katsura, Yoshiaki; Kasahara, Nina; Kasahara, Takashi; Kanamura, Masashi; Kawanabe, Keiichi

    2017-01-01

    Infected periprosthetic femoral fractures are among the most complex and significant complications of total hip arthroplasty (THA). We report the novel use of a temporary THA-like spacer for treating an infected periprosthetic femoral fracture after revision surgery using a long stem. We present a 72-year-old woman sustained a left infected periprosthetic femoral fracture after revi - streptococci in the culture sample. On suspicion of a periprosthetic joint infection, we planned a two-stage procedure. We used a temporary THA-like spacer comprising the removed femoral long stem, which was autoclaved and then reimplanted, and applied a new polyethylene acetabular liner. Both components were cemented in place with antibioticloaded bone cement, without applying strong pressure. Pain control waseasily achieved postoperatively because the fracture had been stabilized early. The THA-like spacer was stable, and allowed a good range of motion without pain. She was allowed to move with a wheelchair and was walk with partial weight bearing without pain. Seven week after the initial THAlike spacer placement, we performed a revision THA after successful control of infection. At the 1-year follow-up, the patient remained free of infection. Temporary antibiotic-loaded cement-coated THA-like spacer using a long stem facilitated the eradication of infection, fracture stabilization, and enables partial weight bearing without pain. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  12. Effects of cement creep on stem subsidence and stresses in the cement mantle of a total hip replacement.

    PubMed

    Lu, Z; McKellop, H

    1997-02-01

    In cemented total hip prostheses, the role of creep of the acrylic cement (polymethyl methacrylate, [PMMA]) in increasing or decreasing the chance of failure of the cement mantle is a subject of ongoing controversy. In the present study we used a three-dimensional finite-element model of a cemented stem to assess the influence of cement creep on subsidence of the stem, and on the stress and strain in the cement under cyclic load, both in the short and long term. The cement layer was assigned the shear and bulk creep moduli of Zimmer regular PMMA cement, which were obtained experimentally. The stem-cement interface was modeled either as (1) completely bonded, (2) completely debonded with friction, or (3) completely debonded and frictionless. Under the cyclic load some cement creep occurred with all three bonding conditions, allowing additional subsidence of the stem and a decrease in the stress components within the cement. During the unloaded period the full recovery of the preload conditions could be reached with the completely bonded and with the frictionless interfaces. With the frictional interface there was residual cement creep, residual stresses within the cement, and residual subsidence of the stem during the unloaded period; however, the reduction of the stress was at most 13% and the subsidence was about 0.46 mm. The much larger subsidence of debonded stems that is often observed clinically might be attributed to the factors which were not included in the present model, such as circumferential bone remodeling.

  13. Good stability but high periprosthetic bone mineral loss and late-occurring periprosthetic fractures with use of uncemented tapered femoral stems in patients with a femoral neck fracture

    PubMed Central

    Sjöö, Helene; Kelly-Pettersson, Paula; Bodén, Henrik; Eisler, Thomas; Stark, André; Muren, Olle

    2014-01-01

    Background and purpose We previously evaluated a new uncemented femoral stem designed for elderly patients with a femoral neck fracture and found stable implant fixation and good clinical results up to 2 years postoperatively, despite substantial periprosthetic bone mineral loss. We now present the medium-term follow-up results from this study. Patients and methods In this observational prospective cohort study, we included 50 patients (mean age 81 (70–92) years) with a femoral neck fracture. All patients underwent surgery with a cemented cup and an uncemented stem specifically designed for fracture treatment. Outcome variables were migration of the stem measured with radiostereometry (RSA) and periprosthetic change in bone mineral density (BMD), measured with dual-energy X-ray absorptiometry (DXA). Hip function and health-related quality of life were assessed using the Harris hip score (HHS) and the EuroQol-5D (EQ-5D). DXA and RSA data were collected at regular intervals up to 4 years, and data concerning reoperations and hip-related complications were collected during a mean follow-up time of 5 (0.2–7.5) years. Results At 5 years, 19 patients had either passed away or were unavailable for further participation and 31 could be followed up. Of the original 50 patients, 6 patients had suffered a periprosthetic fracture, all of them sustained after the 2-year follow-up. In 19 patients, we obtained complete RSA and DXA data and no component had migrated after the 2-year follow-up. We also found a continuous total periprosthetic bone loss amounting to a median of –19% (–39 to 2). No changes in HHS or EQ-5D were observed during the follow-up period. Interpretation In this medium-term follow-up, the stem remained firmly fixed in bone despite considerable periprosthetic bone mineral loss. However, this bone loss might explain the high number of late-occurring periprosthetic fractures. Based on these results, we would not recommend uncemented femoral stems for the

  14. Evaluation of an injectable bioactive borate glass cement to heal bone defects in a rabbit femoral condyle model.

    PubMed

    Cui, Xu; Huang, Wenhai; Zhang, Yadong; Huang, Chengcheng; Yu, Zunxiong; Wang, Lei; Liu, Wenlong; Wang, Ting; Zhou, Jie; Wang, Hui; Zhou, Nai; Wang, Deping; Pan, Haobo; Rahaman, Mohamed N

    2017-04-01

    There is a need for synthetic biomaterials to heal bone defects using minimal invasive surgery. In the present study, an injectable cement composed of bioactive borate glass particles and a chitosan bonding solution was developed and evaluated for its capacity to heal bone defects in a rabbit femoral condyle model. The injectability and setting time of the cement in vitro decreased but the compressive strength increased (8±2MPa to 31±2MPa) as the ratio of glass particles to chitosan solution increased (from 1.0gml(-1) to 2.5gml(-1)). Upon immersing the cement in phosphate-buffered saline, the glass particles reacted and converted to hydroxyapatite, imparting bioactivity to the cement. Osteoblastic MC3T3-E1 cells showed enhanced proliferation and alkaline phosphatase activity when incubated in media containing the soluble ionic product of the cement. The bioactive glass cement showed a better capacity to stimulate bone formation in rabbit femoral condyle defects at 12weeks postimplantation when compared to a commercial calcium sulfate cement. The injectable bioactive borate glass cement developed in this study could provide a promising biomaterial to heal bone defects by minimal invasive surgery.

  15. Adhesive strength of total knee endoprostheses to bone cement - analysis of metallic and ceramic femoral components under worst-case conditions.

    PubMed

    Bergschmidt, Philipp; Dammer, Rebecca; Zietz, Carmen; Finze, Susanne; Mittelmeier, Wolfram; Bader, Rainer

    2016-06-01

    Evaluation of the adhesive strength of femoral components to the bone cement is a relevant parameter for predicting implant safety. In the present experimental study, three types of cemented femoral components (metallic, ceramic and silica/silane-layered ceramic) of the bicondylar Multigen Plus knee system, implanted on composite femora were analysed. A pull-off test with the femoral components was performed after different load and several cementing conditions (four groups and n=3 components of each metallic, ceramic and silica/silane-layered ceramic in each group). Pull-off forces were comparable for the metallic and the silica/silane-layered ceramic femoral components (mean 4769 N and 4298 N) under standard test condition, whereas uncoated ceramic femoral components showed reduced pull-off forces (mean 2322 N). Loading under worst-case conditions led to decreased adhesive strength by loosening of the interface implant and bone cement using uncoated metallic and ceramic femoral components, respectively. Silica/silane-coated ceramic components were stably fixed even under worst-case conditions. Loading under high flexion angles can induce interfacial tensile stress, which could promote early implant loosening. In conclusion, a silica/silane-coating layer on the femoral component increased their adhesive strength to bone cement. Thicker cement mantles (>2 mm) reduce adhesive strength of the femoral component and can increase the risk of cement break-off.

  16. Influence of offset stem couplers in femoral revision knee arthroplasty: a radiographic study.

    PubMed

    Brilhault, Jean M; Ries, Michael D

    2012-03-01

    We questioned whether the use of offset femoral stem would result in modifying the posterior femoral condylar offset (PFCO) in revision knee arthroplasty (RTKA). We measured both PFCO and stem alignment on lateral radiographs of two cohorts: 91 knees with straight stems and 35 knees with offset coupled stems. A higher PCOR was observed in knees with an offset stem compared to knees with straight stem. Knees with an offset stem had a better alignment within the intramedullary canal. Our conclusion is that the use of a modular offset coupler with femoral stem in RTKA compared to a modular straight stem both increases the posterior condylar offset and improves alignment of the stem within the intramedullary canal.

  17. [Bone cement dry prosthetic with internal fixation treat senile osteoporotic femoral fractures].

    PubMed

    Jiang, Y; Rong, X X; Chen, P; Xu, Y J; Zhu, G X

    2017-03-01

    Objective: To explore the treatment of senile osteoporotic femoral fractures after using internal fixation of bone cement dry prosthetic. Methods: Twelve patients aged from 74 to 94 years with mean age of (84.0±2.5) years with internal fixation of bone cement dry prosthetic surgery who were treated at Department of Orthopaedics in Nanjing Medical University Affiliated Wuxi Second Hospital between May 2013 and May 2015 were retrospectively analyzed. There were 8 male and 4 female, 10 cases of tumble and 2 cases of traffic injury. The fracture types with AO type included 1 case of A1 type, 5 cases of A2 type, 3 cases of A3 type, 1 case of B1 type, 2 cases of B2 type. The steel plate internal fixation with bone cement dry prosthetic method was chosen to treat senile severe femoral fracture. Postoperative observation of postoperative pain assessment, hip joint activity and walking ability were evaluated. Paired simple t test and Wilcoxon rank sum test were used to compare the differences of pain score and the ability to walk. Results: Twelve cases received an average of (16.0±3.6) months follow-up. The average hospitalization days are (9.0±1.4) days and average of intraoperative time was (68.0±10.6) minutes. Intraoperative blood loss compared to normal was (106.0±24.2) ml. Patients began walking load and activities in two weeks. The gait and joint activities gradually restored and there were no obvious deformity and no loose internal fixation. All of the patients didn't have fracture shift with breaking plates or screws deformation and have no bone cement reaction. The walking ability was (4.1±0.9) points, the hip joint activities were 98.5°±7.7° and pain scores were 1.22±0.58 by Holden grading standards. The differences of walking ability (Z=-3.126, P<0.05) and pain scores (t=23.047, P<0.001) between pre- and post-operative were statistically significant. One patient had contralateral hip pain, 2 patients had lateral thigh pain, 10 patients returned to

  18. Inefficacy of the cementation of femoral head collapse in glucocorticoid-induced osteonecrosis

    PubMed Central

    Gangji, Valérie; Rooze, Marcel; De Maertelaer, Viviane

    2008-01-01

    The objective of this paper was to assess the efficacy of cementation of the femoral head in stage III glucocorticoid-induced osteonecrosis. Ten hips (nine patients) were treated by the injection of low-viscosity cement to reduce the collapse. The follow up included clinical and radiological assessments preoperatively and at 3, 6 and 12 months after surgery. The visual analogue scale (VAS) score, the Lequesne index and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score did not show any significant improvement. Eight of the ten hips showed a worsening of the collapse and required total hip arthroplasty during follow up. The mean time before total hip replacement was 8.6 ± 7 months. The other two hips did not show any relapse of collapse nor functional worsening at the maximum follow up of 5 years. Our results suggest that cement injection is not a treatment that should be proposed for glucocorticoid-induced osteonecrosis. PMID:18297285

  19. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium-molybdenum, with an integrated cylindrical trunnion bearing at the upper end of the stem that fits into a... head of the device to rotate on its stem. The prosthesis is intended for use with bone cement (§ 888...

  20. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium-molybdenum, with an integrated cylindrical trunnion bearing at the upper end of the stem that fits into a... head of the device to rotate on its stem. The prosthesis is intended for use with bone cement (§ 888...

  1. Trochanteric fragility fractures : Treatment using the cement-augmented proximal femoral nail antirotation.

    PubMed

    Neuerburg, C; Mehaffey, S; Gosch, M; Böcker, W; Blauth, M; Kammerlander, C

    2016-06-01

    Use of standardized cement augmentation of the proximal femur nail antirotation (PFNA) for the treatment of trochanteric fragility fractures, which are associated with high morbidity and mortality, to achieve safer conditions for immediate full weight-bearing and mobilization, thus, improving preservation of function and independency of orthogeriatric patients. Trochanteric fragility fractures (type 31-A1-3). Ipsilateral arthritis of the hip, leakage of contrast agent into the hip joint, femoral neck fractures. Reduction of the fracture on a fracture table if possible, or minimally invasive open reduction of the proximal femur, i. e., using collinear forceps if necessary. Positioning of guidewires for adjustment of the PFNA and the spiral blade, respectively. Exclusion of leakage of contrast agent and subsequent injection of TRAUMACEM™ V(+) into the femoral head-neck fragment via a trauma needle kit introduced into the spiral blade. Dynamic or static locking of the PFNA at the diaphyseal level. Immediate mobilization of the patients with full weight-bearing and secondary prevention, such as osteoporosis management is necessary to avoid further fractures in the treatment of these patients. A total of 110 patients older than 65 years underwent the procedure. Of the 72 patients available for follow-up (average age 85.3 years), all fractures healed after an average of 15.3 months. No complications related with cement augmentation were observed. Approximately 60 % of patients achieved the mobility level prior to trauma.

  2. Periprosthetic bone loss after insertion of an uncemented, customized femoral stem and an uncemented anatomical stem

    PubMed Central

    2011-01-01

    Background and purpose Customized femoral stems are designed to have a perfect fit and fill in the femur in order to achieve physiological load transfer and minimize stress shielding. Dual-energy X-ray absorptiometry (DXA) is regarded as an accurate method for detection of small alterations in bone mineral density (BMD) around hip prostheses. We present medium-term DXA results from a randomized study comparing a customized and an anatomical femoral stem. Methods 100 hips were randomized to receive either the anatomical ABG-I stem or the Unique customized femoral stem, both uncemented. DXA measurements were conducted postoperatively and after 3, 6, 12, 24, 36, and 60 months, and BMD was computed for each of the 7 Gruen zones in the proximal femur. Results Results from 87 patients were available for analysis. 78 completed the 5-year follow-up: 35 patients in the ABG group and 43 patients in the Unique group. In both groups, we found the greatest degree of bone loss in the proximal Gruen zones. In zone 1, there was 15% reduction in BMD in the ABG-I group and 14% reduction in the Unique group. In zone 7, the reduction was 28% in the ABG-I group and 27% in the Unique group. The only statistically significant difference between the groups was found in Gruen zone 4, which is distal to the tip of the stem, with 1.6% reduction in BMD in the ABG-I group and 9.7% reduction in the Unique group (p = 0.003). Interpretation 5-year DXA results showed that because of stress-shielding, proximal bone loss could not be avoided—either for the anatomical ABG-I stem or for the customized Unique stem. PMID:21668387

  3. Open Reduction and Cementation for Femoral Head Fracture Secondary to Avascular Necrosis

    PubMed Central

    Wood, Mark L; McDowell, Cathy M; Kerstetter, Tara L; Kelley, Scott S

    2000-01-01

    Current treatment for femoral head avascular necrosis has shown good results in early stages of disease, but are not as impressive after progression to collapse. We treated 19 patients (20 hips) with Stage III avascular necrosis (AVN) by open reduction augmented by methylmethacrylate cementation. Follow up ranges from 6 months to 2 years (average=8.7 months). We followed patient progress with pre- and post-operative Harris Hip Scores, Womac Osteoarthritis Index and a Health Status Questionnaire (SF36). All patients realized immediate post-operative pain relief and improvement in function. Harris Hip, Womac Osteoarthritis Index and SF36 physical health scores improved significantly from 54.0 to 79.5 (p<0.05), 54.3 to 29.8 (p<0.05) and 28.4 to 42.4 (p<0.05), respectively. Three patients had a conversion to total hip arthroplasty. Cementation is technically simple, burns no bridges and enables patients a rapid recovery. The long term results, in regards to progression of disease and secondary arthritis, are unknown. PMID:10934620

  4. The Influence of Hip Rotation on Femoral Offset Following Short Stem Total Hip Arthroplasty.

    PubMed

    Boese, Christoph K; Bredow, Jan; Ettinger, Max; Eysel, Peer; Thorey, Fritz; Lechler, Philipp; Budde, Stefan

    2016-01-01

    Short stem total hip arthroplasty (THA) is thought to be an advantageous surgical option for young patients. Femoral offset has been identified as an important factor for clinical outcome of THA. However, little is known on functional implications of femoral offset after short stem THA. Importantly, hip rotation influences the projected femoral offset and may lead to significant underestimation. Therefore, a novel method to identify and account for hip rotation was applied to a prospectively enrolled series of 37 patients (48 radiographs) undergoing short stem THA. Repeated measurements were performed and intraobserver and interobserver reliability was assessed and femoral offset was corrected for rotation. Based on this study, rotation-correction of femoral offset is of highest relevance for the correct interpretation in future studies.

  5. Risk Factors for Subsidence of a Modular Tapered Femoral Stem Used for Revision Total Hip Arthroplasty.

    PubMed

    Tangsataporn, Suksan; Safir, Oleg A; Vincent, Alexander D; Abdelbary, Hesham; Gross, Allan E; Kuzyk, Paul R T

    2015-06-01

    The purpose of this study was to determine the incidence, and the clinical and radiographic risk factors for significant subsidence of a cementless, modular tapered revision femoral stem. Femoral stem subsidence of at least 10 mm or subsidence requiring revision was considered significant subsidence. Ninety-seven patients (99 hips) were included with minimum radiographic follow-up of one year (mean 34 months; range, 12-91 months). The mean stem subsidence was 4.5 mm (range, 0-44 mm). Fourteen out of 99 (14.1%) stems had significant subsidence and 6 (6.1%) stems required revision due to subsidence. Patient weight greater than 80 kg (P=0.04) and femoral stem press-fit distance of less than 2 cm (P<0.01) were both independent risk factors for significant stem subsidence.

  6. Substantially higher prevalence of postoperative peri­prosthetic fractures in octogenarians with hip fractures operated with a cemented, polished tapered stem rather than an anatomic stem

    PubMed Central

    Mukka, Sebastian; Mellner, Carl; Knutsson, Björn; Sayed-Noor, Arkan; Sköldenberg, Olof

    2016-01-01

    Background and purpose Recent studies have demonstrated a high incidence of postoperative periprosthetic femoral fracture (PPF) in elderly patients treated with 2 commonly used cemented, polished tapered stems. We compared the prevalence and incidence rate of PPF in a consecutive cohort of octagenerians with femoral neck fractures (FNFs) treated with either a collarless, polished tapered (CPT) stem or an anatomic matte stem (Lubinus SP2). Patients and methods In a multicenter, prospective cohort study, we included 979 hips in patients aged 80 years and above (72% females, median age 86 (80–102) years) with a femoral neck fracture as indication for surgery. 69% of the patients were classified as ASA class 3 or 4. Hip-related complications and repeat surgery were assessed at a median follow-up of 20 (0–24) months postoperatively. Results 22 hips (2.2%) sustained a PPF at a median of 7 (0–22) months postoperatively; 14 (64%) were Vancouver B2 fractures. 7 of the 22 surgically treated fractures required revision surgery, mainly due to deep infection. The cumulative incidence of PPFs was 3.8% in the CPT group, as compared with 0.2% in the SP2 group (p < 0.001). The risk ratio (RR) was 16 (95% CI: 2–120) using the SP2 group as denominator. Interpretation The CPT stem was associated with a higher risk of PPF than the SP2 stem. We suggest that the tapered CPT stem should not be used for the treatment of femoral neck fractures in patients over 80 years. PMID:27045318

  7. Mid-term outcome of a modular, cementless, proximally hydroxyapatite-coated, anatomic femoral stem.

    PubMed

    Cossetto, David J; Goudar, Anil

    2012-12-01

    To report the mid-term outcome of a modular, cementless, proximally hydroxyapatitecoated, anatomic femoral stem in total hip arthroplasty (THA). 160 consecutive patients aged 42 to 92 (mean, 70) years underwent 185 cementless THAs for primary osteoarthritis or femoral neck fractures. All procedures were performed by a single surgeon using the same modular, cementless, proximally hydroxyapatite-coated, anatomic femoral stem, regardless of age and bone quality. Clinical evaluation (pain, range of movement, and ability to walk) was based on the Merle d'Aubigne and Postel scores. Radiological assessment was based on criteria by Engh et al. in the 7 Gruen zones with regard to the presence of radiolucent lines, osteolysis, cancellous condensation, cortical hypertrophy or atrophy, reactive lines, and pedestal formation. Failure of the stem was defined as revision or impending revision because of aseptic loosening or pain. Of the 160 patients, 21 died and none were lost to follow-up. In 3 of the 21 patients, the femoral stems were revised for periprosthetic fractures after a fall at 6 weeks, 10 months, and 3.8 years. 138 patients (162 THAs) completed a mean follow-up of 7.8 (range, 5.5-10.4) years. Their overall mean Merle d'Aubigne and Postel scores increased from 7.09 preoperatively to 16.36 postoperatively. The mean Engh score was 24.9 out of 27, with the mean score for femoral stem fixation 10 out of 10 and 14.9 out of 17 for femoral stem stability. No reactive lines at the bone-stem interfaces and no subsidence or osteolysis were evident in any of the radiographs. There were 5 periprosthetic femoral fractures, 2 deep infections, 3 dislocations, and 2 aseptic loosening (one each for the femoral stem and acetabular socket). Survivorship of the femoral stem at 10 years was 99% when revision secondary to only aseptic loosening of the stem was the endpoint. It was 96% when failures due to all causes (infection, periprosthetic fracture, and aseptic loosening) were the

  8. Contact damage failure analyses of fretting wear behavior of the metal stem titanium alloy-bone cement interface.

    PubMed

    Zhang, Lanfeng; Ge, Shirong; Liu, Hongtao; Wang, Qingliang; Wang, Liping; Xian, Cory J

    2015-11-01

    Although cemented titanium alloy is not favored currently in the Western world for its poor clinical and radiography outcomes, its lower modulus of elasticity and good biocompatibility are instrumental for its ability supporting and transforming physical load, and it is more suitable for usage in Chinese and Japanese populations due to their lower body weights and unique femoral characteristics. Through various friction tests of different cycles, loads and conditions and by examining fretting hysteresis loops, fatigue process curves and wear surfaces, the current study investigated fretting wear characteristics and wear mechanism of titanium alloy stem-bone cement interface. It was found that the combination of loads and displacement affected the wear quantity. Friction coefficient, which was in an inverse relationship to load under the same amplitude, was proportional to amplitudes under the same load. Additionally, calf serum was found to both lubricate and erode the wear interface. Moreover, cement fatigue contact areas appeared black/oxidative in dry and gruel in 25% calf serum. Fatigue scratches were detected within contact areas, and wear scars were found on cement and titanium surfaces, which were concave-shaped and ring concave/ convex-shaped, respectively. The coupling of thermoplastic effect and minimal torque damage has been proposed to be the major reason of contact damage. These data will be important for further studies analyzing metal-cement interface failure performance and solving interface friction and wear debris production issues.

  9. Pulmonary function during and after total hip replacement. Findings in patients who have insertion of a femoral component with and without cement.

    PubMed

    Ries, M D; Lynch, F; Rauscher, L A; Richman, J; Mick, C; Gomez, M

    1993-04-01

    Eleven patients who had a femoral component inserted with cement and twenty-three who had a femoral component inserted without cement were studied prospectively for changes in the pulmonary shunt associated with total hip replacement. The levels of oxygen in the arterial blood and the platelet counts were measured preoperatively and each morning for three days after the arthroplasty. Levels of oxygen in the arterial blood were determined intraoperatively, once before and once after the femoral component was inserted. Intraoperative shunt values increased 28 per cent when a femoral component was inserted with cement (p < 0.05), but they did not change when cement was not used. The average postoperative shunt values were higher than the average preoperative shunt values for both groups of patients, but only the values on the second postoperative day after a procedure with cement were significantly higher (p < 0.05). The ability of the patient to tolerate an increase in pulmonary shunt should be assessed when the femoral component is to be cemented during total hip replacement.

  10. Differences in subsidence rate between alternative designs of a commonly used uncemented femoral stem.

    PubMed

    Al-Najjim, Munnan; Khattak, Usman; Sim, Juluis; Chambers, Iain

    2016-12-01

    Measurement of early subsidence of uncemented femoral stems can be used to evaluate the likelihood of long term stem component loosening and therefore clinical failure. Our aim was to evaluate the factors associated with subsidence in collared and uncollared versions of the Corail femoral stem. 121 hips in 113 consecutive patients were studied, operated on by two surgeons in our hospital differing in their choice of Corail stem. This gave two groups of patients with 66 hips having collared stems and 55 hips having uncollared. We recorded patients' age, sex, ASA grade and BMI. Radiographs post-operatively at day 1, 6 weeks and 1 year were evaluated measuring subsidence, angulation, signs of stability and fixation, and canal fill ratio at the metaphysis and diaphysisafter correcting for magnification errors by calibration using femoral head size. Clinically significant subsidence (>3 mm) occurred in 7.6% of collared and 10.9% of uncollared stems, all within 6-8 weeks, but did not reach statistical significance (p = 0.345). Revision for symptomatic loosening was required in 1 patient in each group (1.5% collared versus 1.8% uncollared). Early subsidence of Corail femoral stem should alert surgeons to closer patient follow-up as the rate of early revision is 18% in stems with >3 mm of subsidence. However, the presence of a collar does not seem to be protective.

  11. Lower reoperation rate for cemented hemiarthroplasty than for uncemented hemiarthroplasty and internal fixation following femoral neck fracture: 12- to 19-year follow-up of patients aged 75 years or more.

    PubMed

    Viberg, Bjarke; Overgaard, Søren; Lauritsen, Jens; Ovesen, Ole

    2013-06-01

    Elderly patients with displaced femoral neck fractures are commonly treated with a hemiarthroplasty (HA), but little is known about the long-term failure of this treatment. We compared reoperation rates for patients aged at least 75 years with displaced femoral neck fractures treated with either internal fixation (IF), cemented HA, or uncemented HA (with or without hydroxyapatite coating), after 12-19 years of follow-up. 4 hospitals with clearly defined guidelines for the treatment of 75+ year-old patients with a displaced femoral neck fracture were included. Cohort 1 (1991-1993) with 180 patients had undergone IF; cohort 2 (1991-1995) with 203 patients had received an uncemented bipolar Ultima HA stem (Austin-Moore); cohort 3 (1991-1995) with 209 patients had received a cemented Charnley-Hastings HA; and cohort 4 (1991-1998) with 158 patients had received an uncemented hydroxyapatite-coated Furlong HA. Data were retrieved from patient files, from the region-based patient administrative system, and from the National Registry of Patients at the end of 2010. We performed survival analysis with adjustment for comorbidity, age, and sex. Cemented HA had a reoperation rate (RR) of 5% and was used as reference in the Cox regression analysis, which showed significantly higher hazard ratios (HRs) for IF (HR = 3.8, 95% CI: 1.9-7.5; RR = 18%), uncemented HA (HR = 2.2, CI: 1.1-4.5; RR = 11%) and uncemented hydroxyapatite-coated HA (HR = 3.6, CI: 1.8-7.4; RR = 16%). Cemented HA has a superior long-term hip survival rate compared to IF and uncemented HA (with and without hydroxyapatite coating) in patients aged 75 years or more with displaced femoral neck fractures.

  12. Do oxidized zirconium femoral heads reduce polyethylene wear in cemented THAs? A blinded randomized clinical trial.

    PubMed

    Zaoui, Amine; Hage, Samer El; Langlois, Jean; Scemama, Caroline; Courpied, Jean Pierre; Hamadouche, Moussa

    2015-12-01

    Charnley low-friction torque total hip arthroplasty (THA) remains the gold standard in THA. The main cause for failure is wear of the socket. Highly crosslinked polyethylene (HXLPE) has been associated with reduced wear rates. Also, oxidized zirconium has shown in vitro reduced wear rates. However, to our knowledge, there are no data comparing oxidized zirconium femoral heads with metal heads against HXLPE or ultrahigh-molecular-weight polyethylene (UHMWPE) when 22.25-mm bearings were used, which was the same size that performed so well in Charnley-type THAs. We hypothesized that after a minimal 4-year followup (1) use of HXLPE would result in lower radiographic wear than UHMWPE when articulating with a stainless steel head or with an oxidized zirconium head; (2) use of oxidized zirconium would result in lower radiographic wear than stainless steel when articulating with UHMWPE and HXLPE; and (3) there would be no difference in terms of Merle d'Aubigné scores between the bearing couple combinations. One hundred patients were randomized to receive cemented THA with either oxidized zirconium or a stainless steel femoral head. UHMWPE was used in the first 50 patients, whereas HXLPE was used in the next 50 patients. There were 25 patients in each of the four bearing couple combinations. All other parameters were identical in both groups. Complete followup was available in 86 of these patients. Femoral head penetration was measured using a validated computer-assisted method dedicated to all-polyethylene sockets. Clinical results were compared between the groups using the Merle d'Aubigné score. In the UHMWPE series, the median steady-state penetration rate from 1 year onward was 0.03 mm/year (range, 0.003-0.25 mm/year) in the oxidized zirconium group versus 0.11 mm/year (range, 0.03-0.29 mm/year) in the metal group (difference of medians 0.08, p < 0.001). In the HXLPE series, the median steady-state penetration rate from 1 year onward was 0.02 mm/year (range, -0.32 to

  13. The effect of femoral component rotation on the five-year outcome of cemented mobile bearing total knee arthroplasty.

    PubMed

    Rienmüller, Anna; Guggi, Thomas; Gruber, Gerald; Preiss, Stefan; Drobny, Tomas

    2012-10-01

    Performing total knee replacement, accurate alignment and neutral rotation of the femoral component are widely believed to be crucial for the ultimate success. Contrary to absolute bone referenced alignment, using a ligament balancing technique does not automatically rotate the femoral component parallel to the transepicondylar axis. In this context we established the hypothesis that rotational alignment of the femoral component parallel to the transepicondylar axis (0° ± 3°) results in better outcome than alignment outside of this range. We analysed 204 primary cemented mobile bearing total knee replacements five years postoperatively. Femoral component rotation was measured on axial radiographs using the condylar twist angle (CTA). Knee society score, range of motion as well as subjective rating documented outcome. In 96 knees the femoral component rotation was within the range 0 ± 3° (neutral rotation group), and in 108 knees the five-year postoperative rotational alignment of the femoral component was outside of this range (outlier group). Postoperative CTA showed a mean of 2.8° (±3.4°) internal rotation (IR) with a range between 6° external rotation (ER) and 15° IR (CI 95). No difference with regard to subjective and objective outcome could be detected. The present work shows that there is a large given natural variability in optimal rotational orientation, in this study between 6° ER and 15° IR, with numerous co-factors determining correct positioning of the femoral component. Further studies substantiating pre- and postoperative determinants are required to complete the understanding of resulting biomechanics in primary TKA.

  14. Anthropometric measurements to design best-fit femoral stem for the Indian population.

    PubMed

    Rawal, Br; Ribeiro, Rahul; Malhotra, Rajesh; Bhatnagar, Naresh

    2012-01-01

    The standard commercially available marketed prostheses sometimes may not be the best fit to Indian patients because of the large anatomic variation. Orthopedic surgeons always stress the need for a proper implant-patient match in hip joint replacements, in particular, for a cementless femoral stem. The complications of mismatch are aseptic loosening, improper load distribution, and discomfort. The present study was undertaken to compare the differences in dimensions between femurs of elderly Indians and those of populations from other regions in order to solve the problem of a possible geometric mismatch between a selected implant and the hip joint as far as Indian patients are concerned. Measurements were made using computer aided design techniques on computed tomography (CT) scanned images of 98 femurs (56 left and 42 right). The software used to convert the CT images into solid models was MIMICS(®) (Materialize, Inc., Leuven, Belgium). The geometrical parameters, viz., the femoral head offset, femoral head center (HC), femoral head diameter, femoral head relative position, position of shaft isthmus, neck-shaft angle, bow angle, femoral neck length, canal flare index, femoral length, and canal width at various locations, were chosen to design best-fit standard femoral stems for cementless insertion. These data were compared with the published data of other countries. A difference of 16.8% was found in the femoral head offset between Indian and Swiss populations, which can affect soft tissue tension and range of motion. At a distance of 20 mm above the lesser trochanter (LT), the anteroposterior (AP) canal width was found to differ by 45.4%, when compared with a French population which can affect the mechanical stability of femoral stem. Femoral dimensions of Indian male and female subjects have also been compared and differences evaluated. At the LT, the aspect ratio (ratio of mediolateral canal width and AP canal width) in case of males (1.198) is

  15. Neutron radiography and tomography investigations on the porosity of the as-cast titanium femoral stem

    NASA Astrophysics Data System (ADS)

    Sutiyoko; Suyitno; Mahardika, M.; Akbar, F.; Juliani; Setiawan; Baroto

    2017-02-01

    Gating system design in the centrifugal casting is one of the factors that influence the porosity of the femoral stem. The objective of this research is to analysis the porosity in the as-cast titanium femoral stem by neutron radiography and tomography. Three gating system designs which in three-ingates, four-ingates, and four-ingates by inversed position of the femoral stem were casted by a vertical centrifugal casting in investment mold. The porosity distribution in the titanium femoral stem was investigated by the neutron radiography film and followed by neutron tomography. The results indicate that there are large internal porosity in the subsurface region on both of the four-ingates designs but only small internal porosity on the three-ingates design. The large porosity also takes place in largest part of the femoral stem at all of the gating system designs. The product may be rejected due to the sub-surface porosity. The three-ingates design has the smallest risk on the reject product.

  16. The effect of cement on hip stem fixation: a biomechanical study.

    PubMed

    Çelik, Talip; Mutlu, İbrahim; Özkan, Arif; Kişioğlu, Yasin

    2017-03-20

    This study presents the numerical analysis of stem fixation in hip surgery using with/without cement methods since the use of cement is still controversial based on the clinical studies in the literature. Many different factors such as stress shielding, aseptic loosening, material properties of the stem, surgeon experiences etc. play an important role in the failure of the stem fixations. The stem fixation methods, cemented and uncemented, were evaluated in terms of mechanical failure aspects using computerized finite element method. For the modeling processes, three dimensional (3D) femur model was generated from computerized tomography (CT) images taken from a patient using the MIMICS Software. The design of the stem was also generated as 3D CAD model using the design parameters taken from the manufacturer catalogue. These 3D CAD models were generated and combined with/without cement considering the surgical procedure using SolidWorks program and then imported into ANSYS Workbench Software. Two different material properties, CoCrMo and Ti6Al4V, for the stem model and Poly Methyl Methacrylate (PMMA) for the cement were assigned. The material properties of the femur were described according to a density calculated from the CT images. Body weight and muscle forces were applied on the femur and the distal femur was fixed for the boundary conditions. The calculations of the stress distributions of the models including cement and relative movements of the contacts examined to evaluate the effects of the cement and different stem material usage on the failure of stem fixation. According to the results, the use of cement for the stem fixation reduces the stress shielding but increases the aseptic loosening depending on the cement crack formations. Additionally, using the stiffer material for the stem reduces the cement stress but increases the stress shielding. Based on the results obtained in the study, even when taking the disadvantages into account, the cement usage

  17. Prospective two-year subsidence analysis of 100 cemented polished straight stems - a short-term clinical and radiological observation.

    PubMed

    Siepen, Wolf; Zwicky, Lukas; Stoffel, Karl Kilian; Ilchmann, Thomas; Clauss, Martin

    2016-09-17

    Cemented stems show good long-term results and the survival of new implants can be predicted by their early subsidence. With EBRA-FCA (Femoral Component Analysis using Einzel-Bild-Röntgen-Analyse) early subsidence as an early indicator for later aseptic loosening can be analysed. For the cemented TwinSys stem mid- and long-term data is only avalible from the New Zeeland Arthroplasty register, thus close monitoring of this implant system is still mandatory. We conducted a 2 year follow up of 100 consecutive hybrid THA (Total hip arthroplasty) of a series of 285 primary THA operated between Jan 2009 und Oct 2010. These 100 received a polished, cemented collarless straight stem (twinSys®, Mathys AG® Bettlach, Switzerland) with an uncemented monobloc pressfit cup (RM pressfit®, Mathys AG® Bettlach, Switzerland). The other patients were treated with the uncemented version of this stem and the same cup. Clinical (Harris Hip Score) and radiological (ap and axial x-rays, cementing quality according to Barrack, alignment) outcomes besides an EBRA-FCA subsidence analysis were performed. Median age at operation was 78 (68 to 93) years. 5 patients died in the course of follow-up unrelated to surgery. The KM (Kaplan-Meier) survival at 2 years for the endpoint reoperation for any reason was 94.9 (95 % confidence interval 90.6-100 %). Survival for the endpoint aseptic loosening at 2 years was 100 %. The HHS (Harris Hip Score) improved from 56 (14-86) preoperatively to 95 (60-100) 2 years after the operation. Cementing results were judged 47 % Grade A, 45 % Grade B and 7 % Grade C. Osteolysis was found in 2 stems without clinical symptoms or correlation to subsidence or cementing quality. The EBRA-FCA analysis showed an average subsidence of -0.30 mm (95 % CI -0.5 mm to -0.1 mm). 11 patients showed a subsidence of more than 1 mm. In this group one patient showed a subsidence of 1.5 mm and one of 3.1 mm without further radiological changes. The twinSys stem

  18. Laser etching causing fatigue fracture at the neck-shoulder junction of an uncemented femoral stem: A case report.

    PubMed

    Jang, Bob; Kanawati, Andrew; Brazil, Declan; Bruce, Warwick

    2013-01-01

    Fatigue fracture of a femoral component in total hip arthroplasty is a rare occurrence but well documented in the literature. It is understood that proximal loosing of a femoral stem with a well fixed stem distally will result in cantilever bending and eventual fatigue fracture of the stem. Other factors which may potentiate a fatigue fracture are material design, implant positioning, and patient characteristics. More recently, laser etching on the femoral neck of an implant has resulted in fatigue fracture. We report a case of a fatigue fracture at the neck-shoulder junction in a well fixed, uncemented, femoral component due to laser etching in the region of high tensile stress.

  19. Reliability of a new method for evaluating femoral stem positioning after total hip arthroplasty based on stereoradiographic 3D reconstruction.

    PubMed

    Guenoun, Benjamin; El Hajj, Firass; Biau, David; Anract, Philippe; Courpied, Jean-Pierre

    2015-01-01

    The goal of this study was to validate a new method for determining femoral stem positioning based on 3D models derived from the EOS biplanar system. Independents observers measured stem anteversion and femoral offset using CT scan and EOS system of 28 femoral stems implanted in composite femurs. In parallel, the same parameters were measured on biplanar lower limb radiographs acquired from 30 patients who had undergone total hip arthroplasty. CT scanner and biplanar X-ray measurements on composite femurs were highly correlated: 0.94 for femoral offset (P < 0.01), 0.98 for stem anteversion (P < 0.01). The inter and intra-observer reproducibility when measuring composite bones was excellent with both imaging modalities as when measuring femoral stem positioning in patients with the biplanar X-ray system.

  20. Minimizing Stress Shielding and Cement Damage in Cemented Femoral Component of a Hip Prosthesis through Computational Design Optimization

    PubMed Central

    Fischer, Justin; Yadav, Rohan

    2017-01-01

    The average life expectancy of many people undergoing total hip replacement (THR) exceeds twenty-five years and the demand for implants that increase the load-bearing capability of the bone without affecting the short- or long-term stability of the prosthesis is high. Mechanical failure owing to cement damage and stress shielding of the bone are the main factors affecting the long-term survival of cemented hip prostheses and implant design must realistically adjust to balance between these two conflicting effects. In the following analysis we introduce a novel methodology to achieve this objective, the numerical technique combines automatic and realistic modeling of the implant and embedding medium, and finite element analysis to assess the levels of stress shielding and cement damage and, finally, global optimization, using orthogonal arrays and probabilistic restarts, were used. Applications to implants, fabricated using a homogeneous material and a functionally graded material, were presented. PMID:28348892

  1. 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.

  2. High risk of early periprosthetic fractures after primary hip arthroplasty in elderly patients using a cemented, tapered, polished stem

    PubMed Central

    Brodén, Cyrus; Mukka, Sebastian; Muren, Olle; Eisler, Thomas; Boden, Henrik; Stark, André; Sköldenberg, Olof

    2015-01-01

    Background and purpose Postoperative periprosthetic femoral fracture (PPF) after hip arthroplasty is associated with considerable morbidity and mortality. We assessed the incidence and characteristics of periprosthetic fractures in a consecutive cohort of elderly patients treated with a cemented, collarless, polished and tapered femoral stem (CPT). Patients and methods In this single-center prospective cohort study, we included 1,403 hips in 1,357 patients (mean age 82 (range 52–102) years, 72% women) with primary osteoarthritis (OA) or a femoral neck fracture (FNF) as indication for surgery (367 hips and 1,036 hips, respectively). 64% of patients were ASA class 3 or 4. Hip-related complications and need for repeat surgery were assessed at a mean follow-up time of 4 (1–7) years. A Cox regression analysis was used to evaluate risk factors associated with PPF. Results 47 hips (3.3%) sustained a periprosthetic fracture at median 7 (2–79) months postoperatively; 41 were comminute Vancouver B2 or complex C-type fractures. The fracture rate was 3.8% for FNF patients and 2.2% for OA patients (hazard ratio (HR) = 4; 95% CI: 1.3–12). Patients > 80 years of age also had a higher risk of fracture (HR = 2; 95% CI: 1.1–4.5). Interpretation We found a high incidence of early PPF associated with the CPT stem in this old and frail patient group. A possible explanation may be that the polished tapered stem acts as a wedge, splitting the femur after a direct hip contusion. Our results should be confirmed in larger, registry-based studies, but we advise caution when using this stem for this particular patient group. PMID:25280133

  3. Subsidence of collarless uncemented femoral stems in total hips replacements performed for trauma.

    PubMed

    Pentlow, Alanna K; Heal, James S

    2012-06-01

    Collarless, uncemented, femoral stems give excellent results in elective hip replacements but few studies look at outcomes in trauma patients. The presence of osteoporosis and subsequent widened femoral canal may compromise the mechanical stability of uncemented femoral stems resulting in early subsidence. The aim of this study was to assess whether early subsidence occurred when collarless uncemented stems were used to treat trauma patients. Post-operative radiographs of 46 patients, mean age 71, who underwent an uncemented, collarless, total hip replacement for trauma, were reviewed. The difference in distance from the calcar to the prosthesis tip between the immediate post operative radiograph and the subsequent follow-up radiograph was calculated and adjusted for magnification. The same procedure was performed on 36 age-matched patients, who underwent elective hip replacements for osteoarthritis. Hospital notes were reviewed to assess for complications and DEXA scans reviewed for trauma patients where available. The mean femoral stem subsidence was significantly greater in the fracture cohort than in elective patients (p=0.001) with mean subsidence of 4.27 mm (range 0.02-22.05 mm) and 1.57 mm (range 0-5.5 mm), respectively. In the fracture cohort there were 4 revisions within 6 months of surgery, 1 for infection and 3 for femoral stem subsidence leading to dislocation. There were no revisions in the elective cohort. This study showed that collarless uncemented stems subsided significantly more when performed for fractures and had a high early revision rate. We recommend that uncemented collarless should not be used in trauma patients requiring total hip replacement. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Revision Total Hip Arthroplasty Using the Cement-in-Cement Technique.

    PubMed

    Amanatullah, Derek F; Pallante, Graham D; Floccari, Lorena V; Vasileiadis, George I; Trousdale, Robert T

    2017-03-01

    The cement-in-cement technique is useful in the setting of revision total hip arthroplasty (THA), especially to gain acetabular exposure, change a damaged or loose femoral component, or change the version, offset, or length of a fixed femoral component. The goal of this retrospective study was to assess the clinical and radiographic characteristics of revision THA using the cement-in- cement technique. Between 1971 and 2013, a total of 63 revision THAs used an Omnifit (Osteonics, Mahwah, New Jersey) or Exeter (Howmedica, Mahwah, New Jersey) stem and the cement-in-cement technique at the senior author's institution. Aseptic loosening (74%) was the predominant preoperative diagnosis followed by periprosthetic fracture (14%), instability (8%), and implant fracture (6%). Mean clinical follow-up was 5.5±3.8 years. The Harris Hip Score had a statistically significant increase of 18.5 points (P<.001) after revision THA using the cement-in-cement technique. There were 13 returns to the operating room, resulting in an overall failure rate of 21%. Eleven (18%) cases required revision THA, but only 1 (2%) revision THA was for aseptic removal of the femoral component. All other femoral implants had no evidence of component migration, cement mantel fracture, or circumferential lucent lines at final follow-up. The patients who underwent cement-in-cement revision THA at the senior author's institution had good restoration of function but a high complication rate. [Orthopedics. 2017; 40(2):e348-e351.]. Copyright 2016, SLACK Incorporated.

  5. Impaction bone grafting and cemented stem revision in periprosthetic hip fractures: a novel surgical technique.

    PubMed

    Dearden, Paul M; Bobak, Peter P; Giannoudis, Peter V

    2014-01-01

    With an ageing population, and increasing longevity of hip arthroplasty prostheses, the incidence of periprosthetic femoral fractures is rising. We present a simple and easily reproducible technique for reduction of any periprosthetic fracture that requires bone graft augmentation. This method facilitates impaction bone grafting to reconstitute lost bone stock and revision using a cemented implant.

  6. Assessment of the equivalence of a generic to a branded femoral stem

    PubMed Central

    Hothi, H.; Henckel, J.; Shearing, P.; Holme, T.; Cerquiglini, A.; Laura, A. Di; Atrey, A.; Skinner, J.; Hart, A.

    2017-01-01

    Aims The aim of this study was to compare the design of the generic OptiStem XTR femoral stem with the established Exeter femoral stem. Materials and Methods We obtained five boxed, as manufactured, implants of both designs at random (ten in total). Two examiners were blinded to the implant design and independently measured the mass, volume, trunnion surface topography, trunnion roughness, trunnion cone angle, Caput-Collum-Diaphyseal (CCD) angle, femoral offset, stem length, neck length, and the width and roughness of the polished stem shaft using peer-reviewed methods. We then compared the stems using these parameters. Results We found that the OptiStems were lighter (p < 0.001), had a rougher trunnion surface (p < 0.001) with a greater spacing and depth of the machined threads (p < 0.001), had greater trunnion cone angles (p = 0.007), and a smaller radius at the top of the trunnion (p = 0.007). There was no difference in stem volume (p = 0.643), CCD angle (p = 0.788), offset (p = 0.993), neck length (p = 0.344), stem length (p = 0.808), shaft width (p = 0.058 to 0.720) or roughness of the polished surface (p = 0.536). Conclusion This preliminary investigation found that whilst there were similarities between the two designs, the generic OptiStem is different to the branded Exeter design. Cite this article: Bone Joint J 2017;99-B:310–16. PMID:28249969

  7. Locking attachment plate fixation around a well-fixed stem in periprosthetic femoral shaft fractures.

    PubMed

    Kim, Min Bom; Cho, Jae-Woo; Lee, Young Ho; Shon, Won-Yong; Park, Jung Wee; Kim, Jinil; Oh, Jong-Keon

    2017-07-08

    Periprosthetic fractures are difficult to manage. Plating technique has been considered a reliable form of management of periprosthetic fractures with a well-fixed stem, but a dependable and stable method of plate fixation to the bone is lacking. This study reports the clinical results using a locking attachment plate (LAP) instead of cable fixation to fix locking plates to a periprosthetic femoral shaft fracture. Nineteen patients with periprosthetic femoral shaft fractures around well-fixed stemmed implants were studied between August 2012 and December 2014. Patients were followed up for at least 1 year postoperatively. Median age was 74 years (range 56-96 years). Fractures were classified according to the Unified Classification System, Vancouver classification, and Su classification. Open reduction was performed under minimal incision and the locking plate was fixed to the lateral cortex of the femoral shaft. The part of the shaft without a stem was fixed to the plate using 5.0-mm locking screws, and the part with an underlying stem was fixed using 3.5-mm locking screws through the LAP instead of cables. Postoperatively, patients were managed using general principles for femoral shaft fractures. Average follow-up was 16 months (range 12-36 months). All cases achieved fracture healing without loss of reduction. There were no cases of implant breakage or stem loosening at final follow-up. The average number of LAPs per fixation construct was 2.1 (range 1-4), and the average number of 3.5-mm locking screws through each LAP was 3.3 (range 2-4). The average value of plate screw density was 0.55 (range 0.37-0.8), and the average working length was four holes (range 2-8). Using the LAP to manage periprosthetic fractures with a well-fixed stem could obviate the need for cable around the stem area and yield acceptable outcomes.

  8. Design process of cementless femoral stem using a nonlinear three dimensional finite element analysis

    PubMed Central

    2014-01-01

    Background Minimal available information concerning hip morphology is the motivation for several researchers to study the difference between Asian and Western populations. Current use of a universal hip stem of variable size is not the best option for all femur types. This present study proposed a new design process of the cementless femoral stem using a three dimensional model which provided more information and accurate analysis compared to conventional methods. Methods This complete design cycle began with morphological analysis, followed by femoral stem design, fit and fill analysis, and nonlinear finite element analysis (FEA). Various femur parameters for periosteal and endosteal canal diameters are measured from the osteotomy level to 150 mm below to determine the isthmus position. Results The results showed better total fit (53.7%) and fill (76.7%) canal, with more load distributed proximally to prevent stress shielding at calcar region. The stem demonstrated lower displacement and micromotion (less than 40 μm) promoting osseointegration between the stem–bone and providing primary fixation stability. Conclusion This new design process could be used as a preclinical assessment tool and will shorten the design cycle by identifying the major steps which must be taken while designing the femoral stem. PMID:24484753

  9. Metal-carbon fiber composite femoral stems in hip replacements: a randomized controlled parallel-group study with mean ten-year follow-up.

    PubMed

    Bennett, D B; Hill, J C; Dennison, J; O'Brien, S; Mantel, J L; Isaac, G H; Beverland, D E

    2014-12-17

    Attempts to improve proximal load transfer and minimize stress shielding have included reducing the stiffness of femoral stems and using alternative stem materials, including carbon fiber composites. An uncemented implant (SR71) composed of a carbon-fiber-composite distal section and a porous-coated titanium-alloy proximal section, designed to improve proximal load transfer and provide good fixation, was clinically evaluated in a prospective randomized study. Sixty patients were enrolled and randomized to receive either the SR71 stem or an all-metal stem (Stability). All patients received a cemented all-polyethylene acetabular component and a 28-mm metal femoral head. All uncemented stems were implanted by the same surgeon. Patients were followed for up to ten years with repeated assessments of bone mineral density, radiographs, Harris hip scores (HHS), and visual analog scale (VAS) pain scores. Ten years postoperatively, nineteen patients who had been treated with the SR71 stem and not lost to follow-up showed a significantly greater increase in proximal bone mineral density (Gruen zones 1 [p = 0.003] and 7 [p = 0.0007]) from baseline than did the twenty-two who had been treated with the Stability stem and not lost to follow-up. In contrast, the Stability group showed a significantly greater increase in distal bone mineral density (Gruen zones 2 [p = 0.0004], 3 [p = 0.0001], and 5 [p = 0.0035]) compared with the SR71 group. Radiographs demonstrated one case of progressive migration of an acetabular component used with an SR71 stem and one case of bone resorption in Gruen zones 7 and 14 in a patient treated with a Stability stem. There was no significant difference between the SR71 and Stability stems in terms of changes in the total HHS, HHS for pain, HHS for range of motion, or VAS pain scores ten years postoperatively relative to preoperative levels. There was one reported revision of an SR71 femoral stem at the ten-year review. The investigational SR71 implant

  10. Heterologous mesenchymal stem cells successfully treat femoral pseudarthrosis in rats

    PubMed Central

    2012-01-01

    Background This study evaluated the effectiveness of treating pseudarthrosis in rats by using bone marrow cell suspensions or cultures of bone marrow mesenchymal stromal cells Methods Thirty-eight specific pathogen-free (SPF) animals were randomly assigned to four groups: Group 1, Control, without surgical intervention; Group 2 (Placebo), experimental model of femoral pseudarthrosis treated only with saline solution; Group 3, experimental model of femoral pseudarthrosis treated with heterologous bone marrow cells suspension; Group 4, experimental model of femoral pseudarthrosis treated with cultures of heterologous mesenchymal stromal cells from bone marrow. When pseudarthrosis was confirmed by simple radiological studies, digital radiography and histopathology after a 120-day postoperative period, Groups 2, 3 and 4 were treated as above. At 30, 60 and 90 days after the treatment, all animals were evaluated by simple radiological studies, and at the end of the experiment, the animals were assessed by computed axial tomography and anatomopathological and histomorphometric examinations. Results Injected cells were detected in the areas affected by pseudarthrosis using scintigraphy within the first 24 hours after their administration. After 60 days, the animals of Group 3 showed callus formation while the animals of Group 4 presented periosteal reaction and had some consolidated areas. In contrast, Group 2 showed a predominance of fibro-osteoid tissue. After 90 days, bone consolidation and remodeling was observed in all animals from Group 3 whereas animals from Group 4 exhibited partial consolidation and those ones from Group 2 persisted with pseudarthrosis. Conclusion The treatment with heterologous bone marrow cells suspension proved to be effective in the treatment of pseudarthrosis whereas cultures of heterologous bone marrow mesenchymal stromal cells did not show the same potential to aid bone healing. PMID:22429995

  11. Long-term results of femoral revision with the Wagner Self-Locking stem.

    PubMed

    Regis, Dario; Sandri, Andrea; Bonetti, Ingrid

    2013-09-01

    Femoral revision total hip arthroplasty may be a complex procedure due to extensive periprosthetic bone loss. Fluted, tapered stems provide secure axial and rotational stability in the distal femur. We retrospectively evaluated the long-term outcome of the cementless Wagner Self-Locking prosthesis (Sulzer Orthopedics Ltd, Winterthur, Switzerland). From 1992 to 1998, 68 consecutive femoral revisions were performed in 66 patients using the Wagner tapered stem. Twenty-five patients deceased for unrelated causes without additional surgery. The studied group consisted of 41 hips in 41 patients, 12 males and 29 females, aged from 29 to 80 years (mean 61 years). Thirty-five hips (85.4%) included severe deficiency of bone stock. A transfemoral approach was carried out in 32 cases (78%). Bone grafting was never supplemented. Average follow-up was 13.9 years (range 10.4 to 15.8 years). Clinical evaluation was performed using Harris Hip Score (HHS). Osseointegration of the stem and progression of periprosthetic bone remodelling were assessed radiographically. Five stems required rerevision because of deep infection (2), progressive subsidence (2) complicated by hip instability and head-neck disassembly, and old dislocation following acetabular component failure (1). Four hips (9.7%) dislocated, and 8 stems (19.5%) subsided significantly. Average HHS improved from 33 points preoperatively to 75 points at the latest follow-up examination (p < 0.001). Thirty-three of the 36 unrevised stems (91.7%) had radiographic evidence of bone ingrowth. A constant or decreased resorption of the femoral bone was detected in 34/36 patients (94.4%). The cumulative survival rates at 15.8 years with femoral revision for any reason and for stem failure as the end points were 92.0% and 96.6%, respectively. The current study documents the efficacy of distal fixation to the diaphysis in revision of bone-deficient femoral components, supporting the use of tapered, fluted stems. Higher

  12. A 5-8 year retrospective follow-up of the C-stem AMT femoral component: patient reported outcomes and survivorship analysis.

    PubMed

    Berstock, James R; Whitehouse, Michael R; Piper, Danielle C; Eastaugh-Waring, Stephen J; Blom, Ashley W

    2014-09-01

    We report midterm functional, radiographic and survivorship data for the cemented, triple taper C-stem AMT femoral component from a consecutive cohort of 415 hip arthroplasties in 386 patients at a non-developer centre. Follow-up ranges were from 60 to 99 months, with a mean of 76 months. 32 hips were lost to follow-up. The median OHS was 40, median SF-12 mental component score (MCS) was 50, and median SF-12 physical component score (PCS) was 39. At 99 months follow up, stem survivorship is 96.9% (95% confidence interval (CI) 82.5-99.5), and construct survivorship is 96.0% (95% CI 84.2-99.0). Adverse events such as calcar fracture, greater trochanter fracture and dislocation were rare at <1%. There have been no revisions for aseptic loosening.

  13. [A comparative study on short-term effectiveness between cemented and uncemented total hip arthroplasty for osteonecrosis of femoral head after renal transplantation].

    PubMed

    Yu, Liankui; Qi, Chao; Yu, Tengbo; Meng, Qingyang; Zhao, Xia; Liu, Kai; Cai, Yan

    2013-12-01

    To compare the short-term effectiveness between primary cemented and uncemented total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH) after renal transplantation. The clinical data were retrospectively analyzed from 18 patients (21 hips) with ONFH after renal transplantation undergoing cemented THA in 11 cases (13 hips) (cemented group) and uncemented THA in 7 cases (8 hips) (uncemented group) between February 2005 and February 2012. There was no significant difference in gender, age, disease duration, ONFH stage, preoperative Harris score, and bone density between 2 groups (P > 0.05). Postoperative complications were observed in 2 groups; the hip function was assessed based on Harris scores; X-ray film was used to observe the prosthetic situation. All the wounds healed by first intention. The patients were followed up 6-77 months (mean, 46 months) in the cemented group, and 4-71 months (mean, 42 months) in the uncemented group. Femoral prosthesis infection occurred in 1 case (1 hip) respectively in each group; hip dislocation, femoral prosthesis loosening, and acetabular prosthesis loosening occurred in 1 case (1 hip) of the cemented group, respectively. At last follow-up, the incidences of postoperative complications and revision rate of the cemented group were 30.7% (4/13) and 23.1% (3/13) respectively, which were significantly higher than those of the uncemented group [12.5% (1/8) and 0 (0/8)] (P=0.047, P=0.040). Harris score was significantly increased to 94.1 +/- 3.7 in the uncemented group and 90.0 +/- 4.2 in the cemented group, showing significant differences compared with the preoperative scores in 2 groups (P < 0.05), but there was no significant difference between 2 groups (t = -1.815, P = 0.062). Postoperative X-ray films showed that the initial position of the prosthesis was satisfactory. At last follow-up, the bone fixation, fibrous stability, and loosening of the femoral prosthesis and loosening of acetabular prosthesis occurred

  14. An Analysis of Reported Cases of Fracture of the Universal Exeter Femoral Stem Prosthesis.

    PubMed

    Bolland, Ben J R F; Wilson, Matthew J; Howell, Jonathan R; Hubble, Matthew J W; Timperley, A John; Gie, Graham A

    2017-04-01

    Between 1991 and 2008, approximately 80 cases of fracture (neck or stem) have been reported. This study aimed at determining factors predisposing to implant fracture. Clinical, surgical, radiological, and retrieval data were collated. Risk factors associated with fracture were categorized to patient related (weight and activity levels), surgical related (poor medial support, component size, and placement), and anatomic/implant related (head size/offset). Data was available on 60 patients (32 stem and 28 neck fractures). Mean patient age at fracture was similar for both neck and stem fractures (69 years, 67 years, respectively). Also, 77% neck and 52% stem fractures occurred in men. Mean weight was 107 kg in neck and 96.5 kg in stem fractures with 68% neck and 38% stem fractures either obese or morbidly obese. Mean time to fracture was 78 months (range, 36-144 months) for neck and 76 months (range, 2-155 months) for stem fractures. 44#2 and 44#3 were the most common sizes associated with neck fractures. Stem fractures occurred more commonly (84%) in the smaller sizes (35.5 to 44#1). Elongated femoral heads were used in 69% neck and 14% stem fractures. Neck fractures were most commonly associated with patient-related (increased weight and activity) and implant-related (use of an elongated femoral head) factors. Stem fractures were most commonly associated with correctable surgical-related causes, predominantly secondary to stem undersizing or inadequate medial support (84%). Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Fate of the unrevised cemented stem following cup only revision: 227 hips at an average of 6 years follow-up.

    PubMed

    McGonagle, L; Siney, P D; Raut, V V

    2015-11-01

    After primary total hip replacement, aseptic loosening of the acetabular cup is more common than loosening of the femoral stem. Removal of a well-fixed stem adds to operative time, blood loss, risk of bone loss and fracture. There is limited evidence that isolated cup revision can be a safe option in revision hip arthroplasty. We question the following regarding the unrevised cemented stem after isolated cup revision: 1) Does the unrevised stem require revision after isolated cup revision? 2) When is the stem subsequently revised? 3) Why is the stem subsequently revised? 4) Do unrevised stems exhibit radiographic loosening? We hypothesise that after isolated cup revision most unrevised stems do not need subsequent revision, and that most do not exhibit evidence of radiographic loosening. A retrospective analysis of all patients who underwent revision of the acetabular component only during revision hip arthroplasty between March 1970 and July 2013 was carried out. We assessed survival of the unrevised stem, reasons for subsequent revision, plus radiographic analysis for stem loosening. Two hundred and twenty-seven hips were included [215 patients with an average age at the time of primary surgery was 47 (13-70) years]. The Charnley stem was used in 161 cases; C-stem 65, Howse 1. Average time between primary surgery and cup revision was 15.9 (1.6-33.4) years. Average follow-up for all stems post-isolated cup revision was 6.1 (0.1-30.7) years. Twenty-eight stems (12.3%) were subsequently revised 5.1 (0.1-12.6) years after the isolated cup revision. Reasons for subsequent revision were: aseptic loosening (10); infection (8); dislocation (6); unreconstructable joint post-loose cup removal (2); fracture (2). Radiographic review was possible on 140 cases. Five femoral stems were revised and 2 others showed evidence of possible radiological loosening but were not revised. To our knowledge this is the largest series showing that isolated cup revision in the place of a well

  16. Study of bone remodeling of two models of femoral cementless stems by means of DEXA and finite elements

    PubMed Central

    2010-01-01

    Background A hip replacement with a cemented or cementless femoral stem produces an effect on the bone called adaptive remodelling, attributable to mechanical and biological factors. All of the cementless prostheses designs try to achieve an optimal load transfer in order to avoid stress-shielding, which produces an osteopenia. Long-term densitometric studies taken after implanting ABG-I and ABG-II stems confirm that the changes made to the design and alloy of the ABG-II stem help produce less proximal atrophy of the femur. The simulation with FE allowed us to study the biomechanical behaviour of two stems. The aim of this study was, if possible, to correlate the biological and mechanical findings. Methods Both models with prostheses ABG-I and II have been simulated in five different moments of time which coincide with the DEXA measurements: postoperative, 6 months, 1, 3 and 5 years, in addition to the healthy femur as the initial reference. For the complete comparative analysis of both stems, all of the possible combinations of bone mass (group I and group II of pacients in two controlled studies for ABG-I and II stems, respectively), prosthetic geometry (ABG-I and ABG-II) and stem material (Wrought Titanium or TMZF) were simulated. Results and Discussion In both groups of bone mass an increase of stress in the area of the cancellous bone is produced, which coincides with the end of the HA coating, as a consequence of the bottleneck effect which is produced in the transmission of loads, and corresponds to Gruen zones 2 and 6, where no osteopenia can be seen in contrast to zones 1 and 7. Conclusions In this study it is shown that the ABG-II stem is more effective than the ABG-I given that it generates higher tensional values on the bone, due to which proximal bone atrophy diminishes. This biomechanical behaviour with an improved transmission of loads confirmed by means of FE simulation corresponds to the biological findings obtained with Dual-Energy X

  17. Application of bone marrow mesenchymal stem cells to the treatment of osteonecrosis of the femoral head

    PubMed Central

    Wang, Cheng; Wang, Yu; Meng, Hao-Ye; Yuan, Xue-Ling; Xu, Xiao-Long; Wang, Ai-Yuan; Guo, Quan-Yi; Peng, Jiang; Lu, Shi-Bi

    2015-01-01

    Osteonecrosis of the femoral head (ONFH) is a type of common and refractory disease in the orthopedic clinic that is primarily caused by a partial obstruction of the blood supply to the femoral head, resulting in a series of pathological processes. Mesenchymal stem cells (MSCs) comprise a mixture of various stem cells in myeloid tissue with multipotential differentiation capacity. They can differentiate into bone cells under specific conditions and can be used to treat ONFH through cell transplantation. This review summarizes research on MSCs in the field of ONFH in recent years, reveals the inner characteristics of MSCs, describes their potential to treat osteonecrosis disease, and analyzes the existing challenges of using MSCs in clinical applications. PMID:26064202

  18. Revision of the acetabular component without cement after a previous acetabular reconstruction with use of a bulk femoral head graft in patients who had congenital dislocation or dysplasia. A follow-up note.

    PubMed

    Bal, B S; Maurer, T; Harris, W H

    1999-12-01

    Revision of an acetabular component that has failed after a total hip arthroplasty in which a bulk femoral head autogenous graft or allograft was used as a structural graft for acetabular reconstruction is an uncommon but complex and challenging procedure. We previously reported the results for seventy hips at an average of 16.5 years after a total hip arthroplasty in which an acetabular reconstruction had been performed with a femoral head graft. In the present study, we evaluated a subset of nine hips from that series that had a subsequent revision of the acetabular component without cement. The purpose of the current study was to assess the usefulness of the bone graft in this revision. The nine patients (nine hips) were followed clinically and radiographically for an average of seventy-six months (range, sixty-one to 114 months) after the index revision. In six hips the autogenous femoral head graft previously had been bolted to the lateral side of the ilium, and in one hip the femoral head allograft had been affixed in this manner. In the two remaining hips, the allograft had been placed within the acetabulum. The hips were classified according to the extent of acetabular bone loss, with use of criteria described previously. Three hips had stage-I bone loss; four, stage-II; and two, stage-IIB. A porous-coated hemispherical acetabular component was inserted without cement and fixed with screws in each hip. At least 70 percent of the porous coating was in contact with viable bone. At the time of the latest follow-up after the index revision, all nine acetabular components were functioning well without loosening or osteolysis and none had been revised. The average Harris hip score was 77 points (range, 61 to 98 points) compared with 49 points (range, 27 to 96 points) preoperatively. One hip had had revision of the femoral stem, and another had had exchange of the acetabular liner because of recurrent dislocations. There was no additional resorption of the

  19. [Renovation stem revision femoral head arthroplasty for unstable intertrochanteric fracture in the elderly].

    PubMed

    Zhang, Peng; Chen, Jing-yong; Li, Zhong; Bi, Meng-na; Zhang, Shang-shang; Zhu, Jiang-wei; Lu, Li-sha

    2013-12-01

    To observe clinical efficacy of renovation stem revision femoral head arthroplasty for the treatment of unstable intertrochanteric fracture in the elderly. Totally 32 elderly patients with unstable intertrochanteric fracture were treated with renovation stem revision femoral head arthroplasty from September 2007 to January 2011. There were 11 males and 21 females with an average age of 83.8 (ranged, 80 to 98) years old,the time from injury to hospital ranged from 4 h to 14 days. According to Evans-Jensen classification, 6 cases were type II a, 20 cases were type II b, and 6 cases were type III. Postoperative mortality, complication rates and Harris hip function score were compared and analyzed to evaluate curative effect. All patients were followed up and no dislocation occurred. Six patients were died during 15 months and 4.5 years; 24 cases recoved to independent wakling at 6 months after operation, and 8 cases walked with stick and walker. The average Harris hip joint function score were (91.56 +/- 2.96), 28 cases got excellent results and 4 cases good. Nine cases occurred complications and healed after treatment. Renovation stem revision femoral head arthroplasty is a active and reliable method in treating unstable intertrochanteric fracture in the elderly.

  20. Osteointegration of femoral stem prostheses with a bilayered calcium phosphate coating.

    PubMed

    Goyenvalle, Eric; Aguado, Eric; Nguyen, Jean-Michel; Passuti, Norbert; Le Guehennec, Laurent; Layrolle, Pierre; Daculsi, Guy

    2006-03-01

    Our purpose was to evaluate the osteointegration of bilayered calcium phosphate (CaP)-coated femoral hip stems in a canine model. A first layer of hydroxyapatite (HA) 20 microm thick and a superficial layer of Biphasic Calcium Phosphate (BCP) 30 microm thick were plasma-sprayed on to the proximal region of sandblasted Ti6Al4V prostheses. Bilayered CaP-coated and non-coated canine femoral stems were implanted bilaterally under general anesthesia in 6 adult female Beagle dogs. After 6 and 12 months, a significant degradation of the bilayered coating occurred with a remainder of 33.1+/-12.4 and 23.6+/-9.2 microm in thickness, respectively. Lamellar bone apposition was observed on bilayered coated implants while fibrous tissue encapsulation was observed on non-coated femoral stems. The bone-implant contacts (BIC) were 91+/-3% and 81+/-8% for coated and 7+/-8% and 8+/-12% for non-coated implants, at 6 and 12 months, respectively. Our study supports the concept of a direct relationship between the biodegradation of CaP coating and the enhanced osteointegration of titanium prostheses. A bilayered CaP coating might therefore enhance bone apposition in the early stages because of the superior bioactivity of the BCP layer while the more stable HA layer might sustain bone bonding over long periods.

  1. The mechanical and biological studies of calcium phosphate cement-fibrin glue for bone reconstruction of rabbit femoral defects.

    PubMed

    Dong, Jingjing; Cui, Geng; Bi, Long; Li, Jie; Lei, Wei

    2013-01-01

    In order to improve the mechanical and biological properties of calcium phosphate cement (CPC, nanometer-biomaterial) for bone reconstruction in the rabbit femoral defect model, fibrin glue (FG, the natural product, purified from the blood) was introduced at three different ratios. The CPC powder and the FG solution were mixed, respectively, at the powder/liquid (P/L) ratios (g/mL) of 1:1, 3:1, and 5:1 (g/mL), and pure CPC was used as a control. After being implanted into the femoral defect in rabbit, the healing process was evaluated by micro-computed tomography scan, biomechanical testing, and histological examination. By micro-computed tomography analysis, the P/L ratio of 1:1 (g/mL) group indicated the largest quantity of new bone formation at 4 weeks, 8 weeks, and 12 weeks after implantation, respectively. Bone volume per trabecular volume of the 1:1 group was highest in the four groups, which was 1.45% ± 0.42%, 7.35% ± 1.45%, and 29.10% ± 1.67% at 4 weeks, 8 weeks, and 12 weeks after the operation, respectively. In the biomechanical tests, the compressive strength and the elastic modulus of the three CPC-FG groups were much higher than those of the pure CPC group at the determined time point (P < 0.05). The histological evaluation also showed the best osseointegration in the 1:1 group at 4 weeks, 8 weeks, and 12 weeks after the operation, respectively. In the 1:1 group, the bone grew into the pore of the cement in the laminar arrangement and connected with the cement tightly at the 12th week after the operation. This present study indicated that the CPC-FG composite at the P/L ratio of 1:1 (g/mL) stimulated bone regeneration better than any other designed group, which suggested that CPC-FG at the P/L ratio of 1:1 has significant potential as the bioactive material for the treatment of bone defects.

  2. Femoral stem incorporating a diamond cubic lattice structure: Design, manufacture and testing.

    PubMed

    Jetté, Bruno; Brailovski, Vladimir; Dumas, Mathieu; Simoneau, Charles; Terriault, Patrick

    2017-08-31

    The current total hip prostheses with dense femoral stems are considerably stiffer than the host bones, which leads to such long-term complications as aseptic loosening, and eventually, the need for a revision. Consequently, the lifetime of the implantation does not match the lifetime expectation of young patients. A femoral stem design featuring a porous structure is proposed to lower its stiffness and allow bone tissue ingrowth. The porous structure is based on a diamond cubic lattice in which the pore size and the strut thickness are selected to meet the biomechanical requirements of the strength and the bone ingrowth. A porous stem and its fully dense counterpart are produced by laser powder-bed fusion using Ti-6Al-4V alloy. To evaluate the stiffness reduction, static testing based on the ISO standard 7206-4 is performed. The experimental results recorded by digital image correlation are analyzed and compared to the numerical model. The numerical and experimental force-displacement characteristics of the porous stem show a 31% lower stiffness as compared to that of its dense counterpart. Moreover, the correlation analysis of the total displacement and equivalent strain fields allows the preliminary validation of the numerical model of the porous stem. Finally, the analysis of the surface-to-volume and the strength-to-stiffness ratios of diamond lattice structures allow the assessment of their potential as biomimetic constructs for load-bearing orthopaedic implants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Reconstruction of bone defects with impacted allograft in femoral stem revision surgery

    PubMed Central

    Moro, Enrique; Cebrian, Juan-Luis; Marco, Fernando; García-López, Antonio; Serfaty, David; López-Durán, Luis

    2007-01-01

    A retrospective clinical review was done on 54 revision hip patients. Radiological analysis examined the Gross and AAOS classifications, stem position, cement mantles, allograft and evolution (subsidence, resorption and remodelling). The Harris Hip score was used for clinical assessment. We used bone bank allograft and a polished non-collared stem LD. The follow-up period was 60.5 months (19.4–152.4), and the average age 68.5 (range: 22–85). There were 21 females and 33 males. The surgical approach was: lateral (5.56%) posterior (91.4%); trochanteric osteotomy: 25.9%; associated acetabular revision: 59.3%; previous operations: 1.9. The preoperative Harris score was 35 (28–40) and rose to 81 (50–99) postoperatively. The stem alignment was neutral (44.44%), varus (38.89%) and valgus (16.67%). The femur/stem diameter relationship was 1.8 (1.2–2.7). There were no changes in stem alignment in 94.4%. An adequate cement mantle was: proximal zone (61.1%), medium zone (27.8%) and distal zone (16.7%). The rate of any subsidence was 38.9% (progressive: 12.96%). The rate of complications was 40.7% and included periprosthetic fracture: 14.8%; superficial infection: 1.9%; deep late infection: 1.9%; dislocation: 3.7%; heterotopic ossification: 13%. The rate of new stem revision was 16.6%. The clinical and radiological success rate was 77.78%. A greater incidence of revisions has been found in stem malalignment, progressive subsidence, a Harris increase of <20 points, allograft resorption, small diameter stems and inadequate cement mantle. We recommend hard impaction and a cement mantle of at least 2 mm. Non-progressive subsidence does not increase stem loosening. The technique has been useful in recovering bone stock in a severely defective femur and achieves a stable reconstruction. The level of evidence was therapeutic study level III-2 (retrospective cohort study; see the instructions to the authors for a complete description of the levels of evidence). PMID

  4. Effects of hydroxyapatite coating on survival of an uncemented femoral stem

    PubMed Central

    2011-01-01

    Background and purpose Hydroxyapatite (HA) is widely used as a coating for uncemented total hip arthroplasty components. This has been suggested to improve implant ingrowth and long-term stability. However, the evidence behind the use of HA coating on femoral stems is ambiguous. We investigated survival of an uncemented, tapered titanium femoral stem that was available either with or without HA coating (Bi-Metric). Patients and methods The stem had been used in 4,772 total hip arthroplasties (THAs) in 4,169 patients registered in the Swedish Hip Arthroplasty Register between 1992 and 2009. 59% of the stems investigated were coated with HA and 41% were uncoated. Kaplan-Meier survival analysis and a Cox regression model with adjustment for age, sex, primary diagnosis, and the type of cup fixation were used to calculate survival rates and adjusted risk ratios (RRs) of the risk of revision for various reasons. Results The 10-year survival rates of the HA-coated version and the uncoated version were about equal when we used revision for any reason as the endpoint: 98% (95% CI: 98–99) and 98% (CI: 97–99), respectively. A Cox regression model adjusting for the covariates mentioned above showed that the presence of HA coating did not have any influence on the risk of stem revision for any reason (RR = 1.0, 95% CI: 0.6–1.6) or due to aseptic loosening (RR = 0.5, CI: 0.2–1.5). There was no effect of HA coating on the risk of stem revision due to infection, dislocation, or fracture. Interpretation The uncemented Bi-Metric stem showed excellent 10-year survival. Our findings do not support the use of HA coating on this stem to enhance implant survival. PMID:21751858

  5. Cemented versus uncemented fixation of the femoral component of the NexGen CR total knee replacement in patients younger than 60 years: a prospective randomised controlled RSA study.

    PubMed

    Gao, Feng; Henricson, Anders; Nilsson, Kjell G

    2009-06-01

    The optimal mode of femoral fixation in total knee arthroplasty (TKA) remains controversial, especially for the young patient. In a prospective randomised study we compared the magnitude and pattern of the fixation of cemented versus uncemented femoral components during 2 years in patients younger than 60 years. Forty-one knees in 41 patients were randomised to receive a NexGen (Zimmer, Warsaw, USA) cruciate-retaining TKA with either a cemented or an uncemented non HA-coated femoral component. The patients were examined by radiostereometric analysis (RSA), as well as clinical and radiological evaluation. The magnitude and pattern of migration as measured by RSA did not differ significantly between the cemented and uncemented fixation during the 2-year follow-up, nor were there any differences between the groups in clinical parameters. These findings suggest that an uncemented and non HA-coated femoral component may behave equally as well as a cemented one in the long-term.

  6. Distal locking stem for revision femoral loosening and peri-prosthetic fractures.

    PubMed

    Mertl, Patrice; Philippot, Remy; Rosset, Philippe; Migaud, Henri; Tabutin, Jacques; Van de Velde, Denis

    2011-02-01

    Revision total hip arthroplasty in the setting of a large proximal femoral deficiency or a peri-prosthetic fracture remains a challenging problem. We describe the development, surgical technique and the use of cementless revision stems with distal inter-locking screws to provide immediate stability of the femoral implant. Results were assessed in a large multicentre French study conducted with the french hip and knee surgery society (SFHG). We retrospectively reviewed 725 revisions using interlocking stems from 14 French orthopaedic departments. Seven different stems were used in this series. In-patient records were retrieved, and in addition to demographic data the indication for revision, the preoperative and postoperative PMA and Harris hip scores were documented. The bone deficiency was classified on the basis of the French National Orthopaedic Meeting (SOFCOT) classification. Intraoperative complications and problems if any were retrieved from operative notes. Clinical status and radiographs at the final follow-up were evaluated, paying special attention to the metaphyseal filling index. Average follow-up was 4.5 years. As for the clinical results, the mean Harris hip score at last follow-up was 81. Therefore, it increased by an average of 31 points. Bone reconstruction was assessed on the cortico-medullary index in the metaphyseal area and at mid-shaft increasing from 36 to 45 and 54 to 63, respectively. Radiologically, 637 implants were stable, and 40 demonstrated subsidence. Forty-eight implants have been revised. We found a significant relation between the metaphyseal filling index, the stability of the stem and the quality of bone reconstruction. Results were analysed with respect to three groups of stems: group 1 was a straight, partially HA-coated implant; group 2 was a curved, fully HA-coated implant; and group 3 was a curved, partially-coated implant. Group 1 showed a significantly higher rate of failure when compared with the others types of implants

  7. Treatment of periprosthetic femoral fractures following total hip arthroplasty with femoral component revision.

    PubMed

    Springer, Bryan D; Berry, Daniel J; Lewallen, David G

    2003-11-01

    Revision total hip arthroplasty is indicated for most periprosthetic fractures that occur around the stem of the femoral implant. The purpose of the present study was to assess the results and complications of revision total hip arthroplasty for the treatment of periprosthetic femoral fractures. We evaluated 118 hips in 116 patients who underwent revision total hip arthroplasty because of an acute Vancouver type-B periprosthetic femoral fracture. The femoral implant used for the revision was a cemented stem in forty-two hips, a proximally porous-coated uncemented stem in twenty-eight, an extensively porous-coated stem in thirty, and an allograft-prosthesis composite or tumor prosthesis in eighteen. The mean duration of follow-up was 5.4 years. Kaplan-Meier analysis demonstrated that the probability of survival was 90% at five years and 79.2% at ten years with revision or removal of the femoral implant for any reason as the end point. Sixteen femoral components were rerevised: ten were rerevised because of loosening; three, because of loosening in association with a fracture nonunion; two, because of recurrent dislocation; and one, because of a new periprosthetic fracture. Additionally, six femoral implants were resected because of deep infection (five) or prosthetic loosening (one). Radiographs of the ninety-six hips with a surviving implant showed that twenty-one had evidence of loosening of the femoral implant, four had a nonunion of the femoral fracture, and two had both a nonunion and loosening of the femoral implant. Revision total hip arthroplasty for the treatment of a periprosthetic fracture around the stem of the femoral implant successfully restored function for most patients. The greatest long-term problems were prosthetic loosening and fracture nonunion. Better results were seen when an uncemented, extensively porous-coated stem was used.

  8. Monitoring the integrity of the cement-metal interface of total joint components in vitro using acoustic emission and ultrasound.

    PubMed

    Davies, J P; Tse, M K; Harris, W H

    1996-08-01

    Debonding of the cement-metal interface of cemented femoral components of total hip arthroplasty has been shown from clinical and autopsy material to be a common occurrence. Experimentally, debonding has been shown to increase markedly the strains in the adjacent cement mantle. Studies of autopsy-retrieved specimens demonstrate that debonding of the cement-metal interface is a key initiating event in loosening of cemented femoral components of total hip arthroplasty. However, both the radiographic and autopsy evidence of cement-metal interfacial debonding exist after the fact, that is, after debonding has occurred. The lack of prospective data showing that debonding does indeed occur under physiologic loading and occurs prior to other forms of failure of fixation leaves uncertain the issue of debonding and its role in initiating loosening of cemented femoral components. Knowing when, where, and to what extent the cement-metal interface debonds is critical information in understanding the process of loosening of cemented femoral components. Such information would contribute to improving the durability of stems and improving cementing techniques. In this study, the two nondestructive techniques of acoustic emission and ultrasonic evaluation of the cement-metal interface of cemented femoral stems of total hip arthroplasty were combined to investigate when, where, and to what extent cement-metal debonding occurred in vitro in simulated femurs loaded physiologically in fatigue in simulated single-leg stance. Debonding of the cement-metal interface of a cemented femoral component in this model was both an initiating event and a major mechanism of compromise of the cement-metal interface. Additional acoustic emission signals arose from cracks that developed in the cement.

  9. Small and similar amounts of micromotion in an anatomical stem and a customized cementless femoral stem in regular-shaped femurs

    PubMed Central

    2014-01-01

    Background and purpose High primary stability is important for long-term survival of uncemented femoral stems. Different stem designs are currently in use. The ABG-I is a well-documented anatomical stem with a press-fit design. The Unique stem is designed for a tight customized fit to the cortical bone of the upper femur. This implant was initially developed for patients with abnormal anatomy, but the concept can also be used in patients with normal femoral anatomy. We present 5-year radiostereometric analysis (RSA) results from a randomized study comparing the ABG-I anatomical stem with the Unique femoral stem. Patients and methods 100 hips with regular upper femur anatomy were randomized to either the ABG-I stem or the Unique femoral stem. RSA measurements were performed postoperatively and after 3, 6, 12, 24, and 60 months. Results RSA measurements from 80 hips were available for analysis at the 5-year follow-up. Small amounts of movement were observed for both stems, with no statistically significant differences between the 2 types. Interpretation No improvement in long-term stability was found from using a customized stem design. However, no patients with abnormal geometry of the upper femur were included in this study. PMID:24650024

  10. A Cannulated Tri-Tapered Femoral Stem for Total Hip Arthroplasty: Clinical and Radiological Results at Ten Years.

    PubMed

    Rajakulendran, Karthig; Strambi, Francesco; Ruggeri, Riccardo; Field, Richard E

    2015-10-01

    We report the ten-year clinical and radiological outcomes of a novel cannulated, tri-tapered femoral stem, used in primary total hip arthroplasty (110 stems in 98 patients). At ten years, two Tri-taper stems had been revised for infection and dislocation. The mean Oxford Hip Score improved from 13.46 pre-operatively, to 37.04. Radiological analysis revealed radiolucent lines in 57 cases, but none exceeded 2 mm thickness. Stem subsidence was identified in 63 cases, with mean distal tip migration of 3.8 mm. Survivorship with revision for aseptic loosening as the end point was 100% at 10 years. Stem survival with revision for any cause was 98.2% (95% CI, 92.9% to 99.5%). The ten-year results of the Tri-taper stem are comparable to other polished, tapered femoral stems. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Cement augmentation of implants--no general cure in osteoporotic fracture treatment. A biomechanical study on non-displaced femoral neck fractures.

    PubMed

    Hofmann-Fliri, Ladina; Nicolino, Tomas I; Barla, Jorge; Gueorguiev, Boyko; Richards, R Geoff; Blauth, Michael; Windolf, Markus

    2016-02-01

    Femoral neck fractures in the elderly are a common problem in orthopedics. Augmentation of screw fixation with bone cement can provide better stability of implants and lower the risk of secondary displacement. This study aimed to investigate whether cement augmentation of three cannulated screws in non-displaced femoral neck fractures could increase implant fixation. A femoral neck fracture was simulated in six paired human cadaveric femora and stabilized with three 7.3 mm cannulated screws. Pairs were divided into two groups: conventional instrumentation versus additional cement augmentation of screw tips with 2 ml TraumacemV+ each. Biomechanical testing was performed by applying cyclic axial load until failure. Failure cycles, axial head displacement, screw angle changes, telescoping and screw cut-out were evaluated. Failure (15 mm actuator displacement) occurred in the augmented group at 12,500 cycles (± 2,480) compared to 15,625 cycles (± 4,215) in the non-augmented group (p = 0.041). When comparing 3 mm vertical displacement of the head no significant difference (p = 0.72) was detected between the survival curves of the two groups. At 8,500 load-cycles (early onset failure) the augmented group demonstrated a change in screw angle of 2.85° (± 0.84) compared to 1.15° (± 0.93) in the non-augmented group (p = 0.013). The results showed no biomechanical advantage with respect to secondary displacement following augmentation of three cannulated screws in a non-displaced femoral neck fracture. Consequently, the indication for cement augmentation to enhance implant anchorage in osteoporotic bone has to be considered carefully taking into account fracture type, implant selection and biomechanical surrounding. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  12. Sr-substituted bone cements direct mesenchymal stem cells, osteoblasts and osteoclasts fate

    PubMed Central

    Panseri, Silvia; Dapporto, Massimiliano; Tampieri, Anna; Sprio, Simone

    2017-01-01

    Strontium-substituted apatitic bone cements enriched with sodium alginate were developed as a potential modulator of bone cells fate. The biological impact of the bone cement were investigated in vitro through the study of the effect of the nanostructured apatitic composition and the doping of strontium on mesenchymal stem cells, pre-osteoblasts and osteoclasts behaviours. Up to 14 days of culture the bone cells viability, proliferation, morphology and gene expression profiles were evaluated. The results showed that different concentrations of strontium were able to evoke a cell-specific response, in fact an inductive effect on mesenchymal stem cells differentiation and pre-osteoblasts proliferation and an inhibitory effect on osteoclasts activity were observed. Moreover, the apatitic structure of the cements provided a biomimetic environment suitable for bone cells growth. Therefore, the combination of biological features of this bone cement makes it as promising biomaterials for tissue regeneration. PMID:28196118

  13. Periprosthetic fractures around the femoral stem: overcoming challenges and avoiding pitfalls

    PubMed Central

    Chen, Antonia F.

    2015-01-01

    Management of periprosthetic fractures around the femoral stem after total hip arthroplasty (THA) represents a significant challenge and optimal treatment remains controversial. The most common treatment paradigm involves treating fractures around a well-fixed stem with osteosynthesis, whereas fractures around a loose stem require revision arthroplasty and those with poor bone require augmentation with bone graft. Paradoxically, the literature reports a higher rate of failure for osteosynthesis around prostheses considered to be well-fixed. Such a high rate of poor outcomes may result not only from difficult fracture fixation and compromised biologic healing, but also from unrecognized peri-implant pathology. Therefore, proper preoperative and intraoperative evaluation is key, and a subset of patients may benefit from alternative management. We review the appropriate methods for evaluation and treatment of Vancouver type B fractures with particular emphasis on avoiding missteps that can lead to failure. PMID:26539451

  14. Periprosthetic fractures around the femoral stem: overcoming challenges and avoiding pitfalls.

    PubMed

    Fleischman, Andrew N; Chen, Antonia F

    2015-09-01

    Management of periprosthetic fractures around the femoral stem after total hip arthroplasty (THA) represents a significant challenge and optimal treatment remains controversial. The most common treatment paradigm involves treating fractures around a well-fixed stem with osteosynthesis, whereas fractures around a loose stem require revision arthroplasty and those with poor bone require augmentation with bone graft. Paradoxically, the literature reports a higher rate of failure for osteosynthesis around prostheses considered to be well-fixed. Such a high rate of poor outcomes may result not only from difficult fracture fixation and compromised biologic healing, but also from unrecognized peri-implant pathology. Therefore, proper preoperative and intraoperative evaluation is key, and a subset of patients may benefit from alternative management. We review the appropriate methods for evaluation and treatment of Vancouver type B fractures with particular emphasis on avoiding missteps that can lead to failure.

  15. 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

  16. Primary cementless hip arthroplasty as a potential risk factor for non-union after long-stem revision arthroplasty in periprosthetic femoral fractures.

    PubMed

    Boesmueller, Sandra; Michel, Marc; Hofbauer, Marcus; Platzer, Patrick

    2015-04-01

    In case of stem loosening in periprosthetic femoral fractures (PPFF), revision arthroplasty should be performed. The first hypothesis of this study was that advanced patient age and female gender shows higher non-union rates. The second hypothesis was that primary cementless arthroplasty is associated with a higher non-union rate compared to cemented primary hip arthroplasty. All PPFF occurring between January 2000 and June 2010 treated by revision arthroplasty were included. Multiple regression analysis was performed to identify independent variables leading to fracture non-union. Eighty one patients (78 % female) met the inclusion criteria. In 20/81 patients (24.7 %) no adequate fracture healing could be determined on radiographs 12 months after revision surgery. Although age and female gender showed a positive correlation with bony non-union after PPFF as expected, the p-values were not statistically significant. Multiple regression analysis revealed primary cementless prosthesis (p = 0.001) to be the only independent variable associated with non-union. Non-cemented primary prosthesis might be a negative predicting factor for the development of non-union after long-stem revision arthroplasty in PPFF. We therefore recommend the thorough debridement of pannus tissue thus inducing bone healing before the implantation of revision prostheses.

  17. Successful transplant of mesenchymal stem cells in induced osteonecrosis of the ovine femoral head: preliminary results.

    PubMed

    Feitosa, Matheus Levi Tajra; Fadel, Leandro; Beltrão-Braga, Patrícia Cristina Baleeiro; Wenceslau, Cristiane Valverde; Kerkis, Irina; Kerkis, Alexandre; Birgel Júnior, Eduardo Harry; Martins, João Flávio Panattoni; Martins, Daniele dos Santos; Miglino, Maria Angélica; Ambrósio, Carlos Eduardo

    2010-10-01

    Evaluate the bone tissue recovery following transplantation of ovine mesenchymal stem cells (MSC) from bone marrow and human immature dental-pulp stem cells (hIDPSC) in ovine model of induced osteonecrosis of femoral head (ONFH). Eight sheep were divided in three experimental groups. First group was composed by four animals with ONFH induced by ethanol through central decompression (CD), for control group without any treatment. The second and third group were compose by two animals, six weeks after ONFH induction received transplantation of heterologous ovine MSC (CD + oMSC), and hIDPSC (CD + hIDPSC), respectively. In both experiments the cells were transplanted without application of any type of immunosupression protocol. Our data indicate that both cell types used in experiments were able to proliferate within injured site providing bone tissue recovery. The histological results obtained from CD+hIDPSC suggested that the bone regeneration in such animals was better than that observed in CD animals. Mesenchymal stem cell transplant in induced ovine osteonecrosis of femoral head by central decompression technique is safe, and apparently favors bone regeneration of damaged tissues.

  18. A comparison of a conventional versus a short, anatomical metaphyseal-fitting cementless femoral stem in the treatment of patients with a fracture of the femoral neck.

    PubMed

    Kim, Y-H; Oh, J-H

    2012-06-01

    We compared the clinical and radiological outcomes of two cementless femoral stems in the treatment of patients with a Garden III or IV fracture of the femoral neck. A total of 70 patients (70 hips) in each group were enrolled into a prospective randomised study. One group received a short anatomical cementless stem and the other received a conventional cementless stem. Their mean age was 74.9 years (50 to 94) and 76.0 years (55 to 96), respectively (p = 0.328). The mean follow-up was 4.1 years (2 to 5) and 4.8 years (2 to 6), respectively. Perfusion lung scans and high resolution chest CTs were performed to detect pulmonary microemboli. At final follow-up there were no statistically significant differences between the short anatomical and the conventional stems with regard to the mean Harris hip score (85.7 (66 to 100) versus 86.5 (55 to 100); p = 0.791), the mean Western Ontario and McMaster Universities Osteoarthritis Index (17 (6 to 34) versus 16 (5 to 35); p = 0.13) or the mean University of California, Los Angeles activity score (5 (3 to 6) versus 4 (3 to 6); p = 0.032). No patient with a short stem had thigh pain, but 11 patients (16%) with a conventional stem had thigh pain. No patients with a short stem had symptomatic pulmonary microemboli, but 11 patients with a conventional stem had pulmonary microemboli (symptomatic in three patients and asymptomatic in eight patients). One hip (1.4%) in the short stem group and eight (11.4%) in the conventional group had an intra-operative undisplaced fracture of the calcar. No component was revised for aseptic loosening in either group. One acetabular component in the short stem group and two acetabular components in the conventional stem group were revised for recurrent dislocation. Our study demonstrated that despite the poor bone quality in these elderly patients with a fracture of the femoral neck, osseo-integration was obtained in all hips in both groups. However, the incidence of thigh pain, pulmonary

  19. Morphological and functional characterization of femoral head drilling-derived mesenchymal stem cells.

    PubMed

    Tatu, Romulus Fabian; Anuşca, Dan Nelu; Groza, Sabine Ştefania; Marusciac, Laura; Bojin, Florina Maria; Tatu, Carmen; Hurmuz, Mihai; Păunescu, Virgil

    2014-01-01

    Adult mesenchymal stem cells (MSCs) were primary identified as bone marrow-derived cells, fibroblast-like morphology, and adherent to plastic surfaces of in vitro culture plate. Their identification criteria evolved in time to a well-established panel of markers (expression of CD73, CD90, and CD105) and functional characteristics (adipogenic, osteogenic, and chondrogenic trilineage differentiation ability), which can be applied to adult mesenchymal stem cells obtained from other tissue sources. We tried to assess the potential stemness of femoral head drilling-derived cells as a new source of mesenchymal stem cells (FH-MSCs). For this purpose, we used the morphological and ultrastructural characteristics defined by scanning and transmission electron microscopy and spindle-shape cellular body, fibroblast-like, with few thick elongations (lamellipodia) and numerous fine, thin cytoplasmic projections (filopodia) that extend beyond the edge of lamellipodia. Immunophenotypical analysis was performed by flow cytometry and immunocytochemical methods and we showed that FH-MSCs share the characteristic markers of MSCs, expressing CD73, CD90, CD105, and being positive for vimentin, and c-kit (CD117). Proliferation rate of these cells was moderate, as revealed by Ki67 immunostaining. Regarding the functional characteristics of FH-MSCs, after appropriate time of induction in specific culture media, the cells were able to prove their trilineage potential and differentiated towards adipocytic, osteogenic, and chondrogenic lineage, as revealed by immunofluorescent staining. We may conclude that femoral head drilling-derived cells can be used as a novel source of stem cells, and employed in diverse clinical settings.

  20. High survival of modular tapered stems for proximal femoral bone defects at 5 to 10 years followup.

    PubMed

    Van Houwelingen, Andrew P; Duncan, Clive P; Masri, Bassam A; Greidanus, Nelson V; Garbuz, Donald S

    2013-02-01

    Currently, the two most commonly used options for the revision of femoral components in North America are: cylindrical, nonmodular, cobalt-chromium stems and tapered, fluted, modular, titanium (TFMT) stems. Previous reports have cited high failure rates with cylindrical cobalt chrome stems in large femoral defects but the longer term survival of the fluted stems is unknown. We examined the 5- to 10-year survival of TFMT stems implanted for severe femoral defects. We reviewed all 65 patients with severe proximal bone defects revised with the TMFT stem between January 2000 and 2006. Ten were lost to followup and seven were dead, leaving 48 patients for followup at 5 to 10 years (mean, 84 months; range, 60-120 months). All patients completed five quality-of-life (QOL) questionnaires. Radiographs were evaluated for loosening, subsidence, and preservation of proximal host bone stock. Implant survivorship was 90%. No patient underwent revision for either subsidence or loosening. Subsidence occurred in seven patients (average, 12.3 mm) but all achieved secondary stability. Five patients underwent revision as a result of fracture of the stem and all had the original standard stem design, which has since been modified. All five implant fractures occurred at the modular stem junction. Mean QOL outcomes were: WOMAC = 81 (pain), Oxford = 75, SF-12 = 54 (mental) and 38 (physical), UCLA Activity = 4, and satisfaction overall = 73. Midterm survivorship of modular titanium stems in large femoral defects is high; however, ongoing surveillance of stem junctional fatigue life is required. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

  1. Preclinical assessment of the long-term endurance of cemented hip stems. Part 2: in-vitro and ex-vivo fatigue damage of the cement mantle.

    PubMed

    Cristofolini, L; Erani, P; Savigni, P; Bordini, B; Viceconti, M

    2007-08-01

    Fatigue damage in the cement mantle surrounding hip stems has been studied in the past. However, so far no quantitative method has been validated for assessing ex-vivo damage and for predicting the in-vitro risk of cement fracture. This work presents a method for measuring cement damage; the cement mantle was sliced and sections were inspected with dye penetrants and an optical microscope. Cracks were counted, measured, and classified by type in each region of the cement mantle. Statistical indicators (in total and per unit volume of cement) were proposed that allow quantitative comparison. The method was first validated on two implant types with known clinical success rate, which were tested in vitro using a physiological loading profile (described in Part 1 of this work). The most relevant indicators were able to detect statistical differences between the two designs. Retrieved cement mantles (the same design as one of the in-vitro stems) from revision surgery were also processed with the same inspection method. Excellent qualitative and quantitative agreement was found between the in-vitro generated fatigue damage and the cracking pattern found in the ex-vivo retrieved cement mantles. This demonstrated the effectiveness of the cement inspection protocol and provided a further validation to the in-vitro testing method.

  2. Resistance to subsidence of an uncemented femoral stem after cerclage wiring of a fissure.

    PubMed

    McCulloch, Ryan S; Roe, Simon C; Marcellin-Little, Denis J; Mente, Peter L

    2012-01-01

    To compare: (1) the force required to initiate subsidence, and (2) the relative subsidence, of femoral stems implanted into intact femora, and then into the same femora in which an induced fissure had been stabilized by cerclage. In vitro, mechanical study. Femora (n=9) from 9 dogs. Femora were prepared for implantation of an uncemented stem. Stems were implanted with continuous and impact loading. After axial loading until a fissure occurred, the stems were extracted, and the fissure stabilized with double-loop cerclage. Stems were reimplanted, and reloaded to failure. Mean±SD load to initiate subsidence in intact femora was 1706±584 N compared with 2379±657 N for cerclaged bones (P=.002). Mean relative subsidence of intact femora was 3.99±2.09 mm compared with 1.79±2.99 mm for cerclaged bones (P=.091). The load to initiate subsidence is increased in femora that have fissured, then have been stabilized with double-loop cerclage, when compared with intact femora. The relative subsidence is not different between intact and stabilized specimens. © Copyright 2011 by The American College of Veterinary Surgeons.

  3. Failure mechanisms in CoCrMo modular femoral stems for revision total hip arthroplasty.

    PubMed

    Wang, Qiong; Parry, Michael; Masri, Bassam A; Duncan, Clive; Wang, Rizhi

    2016-04-28

    In this retrieval study, we reported the failure mechanisms of the CoCrMo-based hip implants. Systematic analyses on the clinically failed modular femoral stems from Revitan™ revision prostheses revealed a multistep fracture process. Multiple microcracks were first developed under the combined action of pitting corrosion and dynamic tensile stress on the lateral side of the CoCrMo connection taper. These microcracks then served as the initiation sites of further corrosion fatigue cracking leading to the final catastrophic failure. This crack initiation process has not been previously reported on retrieved CoCrMo components and our findings provide valuable information on the clinical performance of such implants, as well as the material selection and structural designs of future modular stems. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  4. Use of an Electron Beam Melting Manufactured Titanium Collared Cementless Femoral Stem to Resist Subsidence After Canine Total Hip Replacement.

    PubMed

    Liska, William D; Doyle, Nancy D

    2015-10-01

    To evaluate the effect of a collared electron beam melting (EBM)-manufactured titanium cementless femoral stem on implant subsidence after total hip replacement (THR). Prospective study Dogs (n = 26); 33 THR. Records were maintained on the first 110 consecutive THR using an EBM collared femoral stem. Radiographs on the first 33 THR that had 6-months follow-up were evaluated for implant subsidence. These results were compared to 27 dogs with subsidence after THR with a Co Cr collarless stem. Dogs that had EBM collared stem THR had a mean body weight of 35.4 kg, body condition score (BCS) of 6.21, and mean canal flare index (CFI) of 1.56. EBM stem sizes used (number implanted) were #7 (13), #8 (10), #9 (8), and #10 (2). Subsidence of collared stems did not occur if the collar was in contact with cortical bone during surgery. Subsidence of 1-3 mm occurred closing a gap between the collar and bone if contact was not made during surgery, but subsidence stopped once contact was made. No major complications directly related to the EBM collared stem were encountered. A collar on a cementless femoral stem in contact with cortical bone resists subsidence. © Copyright 2015 by The American College of Veterinary Surgeons.

  5. Mobilization of Endogenous Stem Cell Populations Enhances Fracture Healing in a Murine Femoral Fracture Model

    PubMed Central

    Toupadakis, Chrisoula A.; Granick, Jennifer L.; Sagy, Myrrh; Wong, Alice; Ghassemi, Ehssan; Chung, Dai-Jung; Borjesson, Dori L.; Yellowley, Clare E.

    2013-01-01

    Background Delivery of bone marrow derived stem and progenitor cells to the site of injury is an effective strategy to enhance bone healing. An alternate approach is to mobilize endogenous, heterogeneous stem cells that will home to the site of injury. AMD3100 is an antagonist of the chemokine receptor 4 (CXCR4) that rapidly mobilizes stem cell populations into peripheral blood. Our hypothesis was that increasing circulating numbers of stem and progenitor cells using AMD3100 will improve bone fracture healing. Methods A transverse femoral fracture was induced in C57BL/6 mice, after which they were subcutaneously injected for 3 days with AMD3100 or saline control. Mesenchymal stem cells (MSCs), hematopoietic stem and progenitor cells (HSPCs), and endothelial progenitor cells (EPCs) in the peripheral blood and bone marrow were evaluated via flow cytometry, automated hematology analysis, and cell culture 24 hours after injection and/or fracture. Healing was assessed up to 84 days after fracture by histomorphometry and µCT. Results AMD3100 injection resulted in higher numbers of circulating MSCs, HSCs, and EPCs. µCT data demonstrated that the fracture callus was significantly larger compared to the saline controls at day 21 and significantly smaller (remodeled) at day 84. AMD3100-treated mice have a significantly higher bone mineral density than saline-treated counterparts at day 84. Discussion Our data demonstrate that early cell mobilization had significant positive effects on healing throughout the regenerative process. Rapid mobilization of endogenous stem cells could provide an effective alternative strategy to cell transplantation for enhancing tissue regeneration. PMID:23831362

  6. "Top-Out" Removal of Well-Fixed Dual-Taper Femoral Stems: Surgical Technique and Radiographic Risk Factors.

    PubMed

    Kwon, Young-Min; Antoci, Valentin; Eisemon, Eric; Tsai, Tsung-Yuan; Yan, Yu; Liow, Ming Han Lincoln

    2016-12-01

    Contemporary "dual-taper" modular femoral neck-stem designs have been associated with taper corrosion-related adverse local tissue reaction (ALTR) requiring revision surgery and stem removal. Extended trochanteric osteotomy is recognized as the workhorse procedure for revision hip surgery. The aim of our study is to describe our "top-out" stem removal surgical technique and identify preoperative radiographic risk factors associated with periprosthetic fractures when using this technique. This is a single-center, single-surgeon, retrospective case series. Operative and clinic records were reviewed for patients with dual-taper modular femoral neck-stem junction who underwent revision surgery for taper tribocorrosion-related ALTR. Eighty-three patients (36 men and 47 women; mean age, 61.8 ± 10.3; body mass index, 30.2 ± 8.6) were revised using the top-out technique. Significant improvements in postoperative Harris hip score (P = .004), EuroQol 5-dimension questionnaire (EQ-5D; P < .001), and EQ-5D US-adjusted scores (P < .001) were observed at 19-months follow-up. Our study reports periprosthetic fracture incidence of 14% and reoperation rate of 7%. Periprosthetic fractures were positively correlated with radiographic parameters such as overhang distance (R = 0.376; P = .002) and overhang ratio (R = 0.312; P = .01) and negatively correlated with radiographic implant medial calcar prominence (R = -0.299; P = .01). Removal of well-fixed femoral components can be challenging, and the burden of revision surgery for taper tribocorrosion-related ALTR of these femoral stems is likely to rise. A top-out technique with systematic preoperative planning with radiographs provides a viable, alternative surgical option to remove well-fixed femoral component while preserving the femoral bony envelope. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. The influence of uncemented femoral stem length and design on its primary stability: a finite element analysis.

    PubMed

    Reimeringer, M; Nuño, N; Desmarais-Trépanier, C; Lavigne, M; Vendittoli, P A

    2013-01-01

    One of the crucial factors for short- and long-term clinical success of total hip arthroplasty cementless implants is primary stability. Indeed, motion at the bone-implant interface above 40 μm leads to partial bone ingrowth, while motion exceeding 150 μm completely inhibits bone ingrowth. The aim of this study was to investigate the effect of two cementless femoral stem designs with different lengths on the primary stability. A finite element model of a composite Sawbones(®) fourth generation, implanted with five lengths of the straight prosthesis design and four lengths of the curved prosthesis design, was loaded with hip joint and abductor forces representing two physiological activities: fast walking and stair climbing. We found that reducing the straight stem length from 146 to 54 mm increased the average micromotion from 17 to 52 μm during fast walking, while the peak value increased from 42 to 104 μm. With the curved stem, reducing length from 105 to 54 mm increased the average micromotion from 10 to 29 μm, while the peak value increased from 37 to 101 μm. Similar findings are obtained for stair climbing for both stems. Although the present study showed that femoral stem length as well as stem design directly influences its primary stability, for the two femoral stems tested, length could be reduced substantially without compromising the primary stability. With the aim of minimising surgical invasiveness, newer femoral stem design and currently well performing stems might be used with a reduced length without compromising primary stability and hence, long-term survivorship.

  8. Cemented Müller straight stem total hip replacement: 18 year survival, clinical and radiological outcomes

    PubMed Central

    Nikolaou, Vasileios S; Korres, Demetrios; Lallos, Stergios; Mavrogenis, Andreas; Lazarettos, Ioannis; Sourlas, Ioannis; Efstathopoulos, Nicolas

    2013-01-01

    AIM: To present the 18 year survival and the clinical and radiological outcomes of the Müller straight stem, cemented, total hip arthroplasty (THA). METHODS: Between 1989 and 2007, 176 primary total hip arthroplasties in 164 consecutive patients were performed in our institution by the senior author. All patients received a Müller cemented straight stem and a cemented polyethylene liner. The mean age of the patients was 62 years (45-78). The diagnosis was primary osteoarthritis in 151 hips, dysplasia of the hip in 12 and subcapital fracture of the femur in 13. Following discharge, serial follow-up consisted of clinical evaluation based on the Harris Hip Score and radiological assessment. The survival of the prosthesis using revision for any reason as an end-point was calculated by Kaplan-Meier analysis. RESULTS: Twenty-four (15%) patients died during the follow-up study, 6 (4%) patients were lost, while the remaining 134 patients (141 hips) were followed-up for a mean of 10 years (3-18 years). HSS score at the latest follow-up revealed that 84 hips (59.5%) had excellent results, 30 (22.2%) good, 11 (7.8%) fair and 9 (6.3%) poor. There were 3 acetabular revisions due to aseptic loosening. Six (4.2%) stems were diagnosed as having radiographic definitive loosening; however, only 1 was revised. 30% of the surviving stems showed no radiological changes of radiolucency, while 70% showed some changes. Survival of the prosthesis for any reason was 96% at 10 years and 81% at 18 years. CONCLUSION: The 18 year survival of the Müller straight stem, cemented THA is comparable to those of other successful cemented systems. PMID:24147267

  9. The potential application of a Cobalt Chrome Molybdenum femoral stem with functionally graded orthotropic structures manufactured using Laser Melting technologies.

    PubMed

    Hazlehurst, K B; Wang, C J; Stanford, M

    2013-12-01

    The cementless fixation of porous coated femoral stems is a common technique employed for Total Hip Arthroplasty (THA). With the rate of revision surgery appearing to rise and younger more active patients requiring primary surgery it can be thought that alternative methods for increasing implant longevity need to be considered. The stress shielding of periprosthetic bone still remains a contributing factor to implant loosening, caused through a mismatch in stiffness between the implant and the bone. However, the ability to achieve stiffness matching characteristics is being realised through the use of Additive Layer Manufacturing (ALM) technologies and Functionally Graded Materials (FGM). This paper proposes an alternative design methodology for a monoblock Cobalt Chrome Molybdenum (CoCrMo) femoral stem. It hypothesises that a femoral stem suitable for cementless fixation can be manufactured using Laser Melting (LM) technology offering orthotropic functionally graded porous structures with similar mechanical properties to human bone. The structure and mechanical properties of the natural femur have been used as a basis for the design criteria which hypothesises that through a combination of numerical analysis and physical testing, an optimal design can be proposed to provide a lightweight, customised femoral stem that can reduce the risk of implant loosening through stress shielding whilst maintaining bone-implant interface stability. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Prospective randomised clinical trial assessing subsidence and rotation, using radiostereometric analysis, of two modular cementless femoral stems (Global K2 and Apex)

    PubMed Central

    Edmondson, Mark; Ebert, Jay; Nivbrant, Oscar; Wood, David

    2014-01-01

    Aims To accurately assess subsidence, rotation and clinical scores in two cementless femoral stems. Methods 260 patients received either K2 or Apex femoral stems and were studied over 2y, with RSA and clinical scores. Results Mean Oxford Hip score for both stems was excellent (45.78 and 46.76). Very little subsidence or rotation were noted on RSA in either stem. There were no statistically significant differences in clinical scores, or radiological motion between stems. Revision rate was 0.8% over the study period. Conclusion Excellent clinical and RSA scores over the 2y study period predict good long term outcomes for these stems. PMID:25104894

  11. Femoral catheters: safety and efficacy in peripheral blood stem cell collection.

    PubMed

    Adorno, G; Zinno, F; Bruno, A; Lanti, A; Ballatore, G; Masi, M; Cudillo, L; Del Poeta, G; Riccitelli, A; Del Principe, M I; Pepe, R; Marchitelli, E; Morosetti, M; Meloni, C; Isacchi, G; Amadori, S

    1999-10-01

    Central venous access is necessary in patients candidate for peripheral blood stem cell (PBSC) collection. We report our experience with a dual lumen femoral catheter (Gamcath, 11 french), initially designed for hemodialysis. We studied 147 patients and performed 488 collections after mobilization with either G-CSF alone or chemotherapy + G-CSF, when the white blood cell count exceeded 1 x 10(9)/L, or when a measurable population of CD34+ cells (20/microL) was detected in peripheral blood. All patients received systemic anticoagulation with a low weight heparin and ultrasound examination was performed after the removal of the catheter. Seven patients developed thrombosis (4.7%), ten experienced hematomas at the site of catheter placement (6.8%) despite prophylactic platelet transfusions, while only one patient (0.6%) had a catheter-related infection. In conclusion, the short-term use of large bore femoral catheters in setting up PBSC collection seems to be associated with minimal risk of infection and low thrombotic incidence.

  12. Autopsy studies of the bone-cement interface in well-fixed cemented total hip arthroplasties.

    PubMed

    Schmalzried, T P; Maloney, W J; Jasty, M; Kwong, L M; Harris, W H

    1993-04-01

    Although knowledge of the clinical status of the implant is important, only instrumented mechanical testing of retrieved specimens provides quantitative assessment of implant fixation. This measurement allows placement of the implant along a continuum of loosening and is the foundation for the interpretation of subsequent findings. Analysis of implants that have been proven to be well fixed by instrumented testing reveals significant differences in the initial events in the loosening of femoral and acetabular components. Although radiolucencies were observed around all of these well-fixed femoral and acetabular components, the histology (and therefore the etiology) of the radiolucency is different and variable on the two sides of the articulation. The majority of femoral radiolucencies appear to be due to age and stress-related remodeling while particulate-induced bone resorption plays an important role in acetabular radiolucencies. A finding common to both sides of the articulation in these stable components, however, was intimate contact of bone with cement without any interposed soft tissue even after 17.5 years of service. Primary incompatibility and/or failure of the cement was not identified as a factor in initiating either femoral or acetabular component loosening. These studies document the long-term compatibility of bone with cement in bulk form. Improvements in cemented femoral component fixation should focus on stem design and cementing technique. Long-term acetabular component fixation can be improved by reduction or elimination of polyethylene wear and optimization of the bone-implant interface.

  13. Biomechanical Comparison of 2 Different Femoral Stems in the Shortening Osteotomy of the High-Riding Hip.

    PubMed

    Tuncay, Ibrahim; Yıldız, Fatih; Bilsel, Kerem; Uzer, Gökçer; Elmadağ, Mehmet; Erden, Tunay; Bozdağ, Ergun

    2016-06-01

    We hypothesized that a rectangular cross-sectional femoral stem may produce more initial stability of the transverse subtrochanteric femoral shortening osteotomy rather than a circular cross-sectional stem. Twenty, fourth-generation, synthetic femur models were inserted with either circular or rectangular cross-sectional femoral stems after 3 cm of transverse subtrochanteric shortening. Half of the models were tested with axial bending and the other half with torsional loads. After the femora underwent cyclic loading, they were loaded until failure. Outcome parameters were stiffness values before and after cyclical loading, failure loads/torques, and displacements at the osteotomy sites. In axial bending tests, the results were not significantly different between the groups. Under rotational forces, the mean stiffness value before cyclical loading and failure torque of the cylindrical stems was significantly higher than that of rectangular cross-sectional stems (11.8 ± 1.2 vs 7.1 ± 2.8 Nm/degree; P = .009 and 136.9 ± 60.2 vs 27.1 ± 17.5 Nm; P = .027 Nm, respectively). The mean amounts of displacements at the osteotomy sites were not significantly different between the groups in any direction in both axial and rotational tests. According to the results of the study, using straight, cylindrical femoral stems can increase rotational stability of the transverse osteotomy more than the rectangular cross-sectional stems although the latter one has the advantages of rectangular geometrical design. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Total hip arthroplasty with cement and use of a collared matte-finish femoral component: nineteen to twenty-year follow-up.

    PubMed

    Callaghan, John J; Liu, Steve S; Firestone, Daniel E; Yehyawi, Tameem M; Goetz, Devon D; Sullivan, Jason; Vittetoe, David A; O'Rourke, Michael R; Johnston, Richard C

    2008-02-01

    In the mid- to late 1970s, on the basis of laboratory and finite element data, many surgeons in the United States began using collared matte-finish femoral components and metal-backed acetabular components in their total hip arthroplasties. The purpose of this study was to evaluate the long-term results of the use of one such construct in arthroplasties performed by a single surgeon in a consecutive nonselected patient cohort. Between January 1984 and December 1985, 273 patients underwent a total of 304 consecutive nonselected total hip arthroplasties with cement and use of the Iowa femoral component (which is collared, has a proximal cobra shape, and has a matte finish) and a metal-backed TiBac acetabular component performed by a single surgeon. At nineteen to twenty years postoperatively, only two patients (two hips) were lost to follow-up. For clinical evaluation, we attempted to interview all living patients and the families of the patients who had died to verify the status of the hip prosthesis or any revisions. Radiographic evaluation consisted of analysis for loosening and osteolysis as well as wear of the acetabular component. At the time of the nineteen to twenty-year follow-up, the rate of revision of the arthroplasty for any reason was 10.5% (thirty-two hips) for all patients and 25% (twenty-three hips) for living patients. The rate of revision due to aseptic femoral loosening was 2.6% (eight hips). There was radiographic evidence of loosening of the femoral component in fifteen hips (4.9%), including those that were revised, and femoral osteolysis was seen distal to the trochanters in twenty-two hips (7.2%). The rate of revision due to aseptic loosening of the acetabular component was 7.9% (twenty-four hips), and there was radiographic evidence of acetabular loosening in forty-two hips (13.8%), including those that were revised. This study demonstrates the durability of a cemented matte-finish collared femoral component at twenty years postoperatively

  15. Midterm results of a femoral stem with a modular neck design: clinical outcomes and metal ion analysis.

    PubMed

    Silverton, Craig D; Jacobs, Joshua J; Devitt, Jeffrey W; Cooper, H John

    2014-09-01

    Modular neck femoral stems have a higher-than-anticipated rate of failure in registry results, but large single-center cohort studies are lacking. This is a retrospective cohort of 152 hips implanted with a single titanium stem with a modular titanium neck, presenting clinical, radiographic, and metal ion results at a mean 4.5-year follow-up. Five hips were revised during the study period, for an overall Kaplan-Meier survival of 0.894 at 8 years. There was one modular neck fracture (0.66%), but others demonstrated corrosion or adverse tissue reaction. Serum metal levels demonstrated wide variability. Despite good clinical results in the majority of patients, we confirmed an increased rate of femoral revision at mid-term follow-up, and therefore urge caution in the use of this particular stem design. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Intravenous transplantation of allogeneic bone marrow mesenchymal stem cells and its directional migration to the necrotic femoral head.

    PubMed

    Li, Zhang-hua; Liao, Wen; Cui, Xi-long; Zhao, Qiang; Liu, Ming; Chen, You-hao; Liu, Tian-shu; Liu, Nong-le; Wang, Fang; Yi, Yang; Shao, Ning-sheng

    2011-01-09

    In this study, we investigated the feasibility and safety of intravenous transplantation of allogeneic bone marrow mesenchymal stem cells (MSCs) for femoral head repair, and observed the migration and distribution of MSCs in hosts. MSCs were labeled with green fluorescent protein (GFP) in vitro and injected into nude mice via vena caudalis, and the distribution of MSCs was dynamically monitored at 0, 6, 24, 48, 72 and 96 h after transplantation. Two weeks after the establishment of a rabbit model of femoral head necrosis, GFP labeled MSCs were injected into these rabbits via ear vein, immunological rejection and graft versus host disease were observed and necrotic and normal femoral heads, bone marrows, lungs, and livers were harvested at 2, 4 and 6 w after transplantation. The sections of these tissues were observed under fluorescent microscope. More than 70 % MSCs were successfully labeled with GFP at 72 h after labeling. MSCs were uniformly distributed in multiple organs and tissues including brain, lungs, heart, kidneys, intestine and bilateral hip joints of nude mice. In rabbits, at 6 w after intravenous transplantation, GFP labeled MSCs were noted in the lungs, liver, bone marrow and normal and necrotic femoral heads of rabbits, and the number of MSCs in bone marrow was higher than that in the, femoral head, liver and lungs. Furthermore, the number of MSCs peaked at 6 w after transplantation. Moreover, no immunological rejection and graft versus host disease were found after transplantation in rabbits. Our results revealed intravenously implanted MSCs could migrate into the femoral head of hosts, and especially migrate directionally and survive in the necrotic femoral heads. Thus, it is feasible and safe to treat femoral head necrosis by intravenous transplantation of allogeneic MSCs.

  17. Improve the performance of coated cemented hip stem through the advanced composite materials.

    PubMed

    Hedia, H S; Fouda, N

    2015-01-01

    Design of hip joint implant using functionally graded material (FGM) (advanced composite material) has been used before through few researches. It gives great results regarding the stress distribution along the implant and bone interfaces. However, coating of orthopaedic implants has been widely investigated through many researches. The effect of using advanced composite stem material, which mean by functionally graded stem material, in the total hip replacement coated with the most common coated materials has not been studied yet. Therefore, this study investigates the effect of utilizing these two concepts together; FGM and coating, in designing new stem material. It is concluded that the optimal FGM cemented stem is consisting from titanium at the upper stem layers graded to collagen at a lower stem layers. This optimal graded stem coated with hydroxyapatite found to reduce stress shielding by 57% compared to homogenous titanium stem coated with hydroxyapatite. However, the optimal functionally graded stem coated with collagen reduced the stress shielding by 51% compared to homogenous titanium stem coated with collagen.

  18. Three-dimensional culture of dental pulp stem cells in direct contact to tricalcium silicate cements.

    PubMed

    Widbiller, M; Lindner, S R; Buchalla, W; Eidt, A; Hiller, K-A; Schmalz, G; Galler, K M

    2016-03-01

    Calcium silicate cements are biocompatible dental materials applicable in contact with vital tissue. The novel tricalcium silicate cement Biodentine™ offers properties superior to commonly used mineral trioxide aggregate (MTA). Objective of this study was to evaluate its cytocompatibility and ability to induce differentiation and mineralization in three-dimensional cultures of dental pulp stem cells after direct contact with the material. Test materials included a new tricalcium silicate (Biodentine™, Septodont, Saint-Maur-des-Fossés, France), MTA (ProRoot® MTA, DENSPLY Tulsa Dental Specialities, Johnson City, TN, USA), glass ionomer (Ketac™ Molar Aplicap™, 3M ESPE, Seefeld, Germany), human dentin disks and polystyrene. Magnetic activated cell sorting for to the surface antigen STRO-1 was performed to gain a fraction enriched with mesenchymal stem cells. Samples were allowed to set and dental pulp stem cells in collagen carriers were placed on top. Scanning electron microscopy of tricalcium silicate cement surfaces with and without cells was conducted. Cell viability was measured for 14 days by MTT assay. Alkaline phosphatase activity was evaluated (days 3, 7, and 14) and expression of mineralization-associated genes (COL1A1, ALP, DSPP, and RUNX2) was quantified by real-time quantitative PCR. Nonparametric statistical analysis for cell viability and alkaline phosphatase data was performed to compare different materials as well as time points (Mann-Whitney U test, α = 0.05). Cell viability was highest on tricalcium silicate cement, followed by MTA. Viability on glass ionomer cement and dentin disks was significantly lower. Alkaline phosphatase activity was lower in cells on new tricalcium silicate cement compared to MTA, whereas expression patterns of marker genes were alike. Increased cell viability and similar levels of mineralization-associated gene expression in three-dimensional cell cultures on the novel tricalcium silicate cement and mineral

  19. Periprosthetic fracture around a stable femoral stem treated with locking plate osteosynthesis: distal femoral locking plate alone versus with cerclage cable.

    PubMed

    Shin, Young-Soo; Han, Seung-Beom

    2017-07-01

    To promote rapid bone healing, an adequate stable fixation implant with a percutaneous reduction instrument should be used for Vancouver type B1 or C fractures. The objective of this study was to describe radiographic and clinical outcomes of patients with periprosthetic fracture (PPF) around a stable femoral stem, treated with a distal femoral locking plate alone or with a cerclage cable. A total of 21 patients with PPF amenable to either a reverse distal femoral locking plate (LCP DF(®)) alone or with a cerclage cable, with a mean age of 75.7 years, were included. In these patients, ten fractures were treated with a reverse LCP DF(®) alone and were classified as group I, and 11 additionally received a cerclage cable and were classified as group II. Group II had a significantly longer operation time (P = 0.019) than group I and included one patient with nonunion at the final 24-month follow-up visit after the initial fracture reduction. However, this difference in nonunion rate for the two groups is more likely to inappropriate indications than surgical techniques. When comparing the stability of the fractures in both groups, there was no statistically significant difference, which might be attributed to the stable fixed-angle implant.

  20. Structural allograft and cemented long-stem prosthesis for complex revision hip arthroplasty: use of a trochanteric claw plate improves final hip function

    PubMed Central

    Lemoine, Camille Thevenin; Kerboull, Marcel; Courpied, Jean Pierre

    2007-01-01

    Extensive bone loss raises formidable challenges in total hip revision. The aim of this study was to evaluate the results of reconstruction using a cemented long-stem and massive structural allograft implanted in a filleted proximal femur, with and without the use of a trochanteric claw plate. Between 1988 and 2001, 44 revisions were performed in 42 patients. After a transtrochanteric approach, the femur was cut longitudinally. A long, cemented Charnley-type prosthesis was used, and flaps of the residual femur were folded around the allograft. The greater trochanter was reinserted with wires in all revisions, and with both wires and a claw plate in 20 revisions. Mean follow-up was 7.15 years (range: 3–16); seven patients, died and four were lost to follow-up. The follow-up exceeded five years in 34 patients. The major complication was nonunion of the greater trochanter, which occurred in 25 cases. Six dislocations, one recurrence of infection, two mechanical loosening, and two fractures below the stem were also recorded. The use of a trochanteric claw plate significantly improved final hip stability, even in patients with nonunion. Femoral reconstruction with a massive structural allograft is reliable and long-lived, and serious complications and long-term resorption are uncommon. The use of a trochanteric claw plate significantly improves final hip stability. Level of evidence: Therapeutic study, level III (retrospective comparative study). PMID:18008098

  1. Histological findings of the femoral bone after cement removal in hip revision. An experimental study of cadaver femurs with two different cement removal procedures.

    PubMed

    Porsch, M; Schmidt, J

    2003-06-01

    Cement removal in hip revision arthroplasty is often a time-consuming procedure, lengthy and tedious. Intraoperative bone damage is one of the more common complications. In the present study, the conventional cement removal method is compared with a new method by means of a histological study concerning potential negative effects to cortical or spongious bone. Histological studies on human cadaver femurs demonstrate no deleterious effects on the endosteal bone when cement was removed with this new device. The ballistically driven chiselling system (OrthoClast) is safe to the bone stock and shows no increased risk of bone damage over the conventional technique with mallet and chisel.

  2. The effect of stem surface treatment and material on pistoning of ulnar components in linked cemented elbow prostheses.

    PubMed

    Hosein, Yara K; King, Graham J W; Dunning, Cynthia E

    2013-09-01

    The ulnar component of a total elbow replacement can fail by "pistoning." Stem surface treatments have improved stability at the stem-cement interface but with varied success. This study investigated the role of surface treatment and stem substrate material on implant stability under axial loading. Sixty circular stems (diameter, 8 mm) made of cobalt chrome (n = 30) or titanium (n = 30) had different surfaces: smooth, sintered beads, and plasma spray. The surface treatment length was either 10 mm or 20 mm. Stems were potted in bone cement, allowed to cure for 24 hours, and tested in a materials testing machine under a compressive staircase loading protocol. Failure was defined as 2 mm of push-out or completion of the protocol. Two-way analyses of variance compared the effects of surface treatment and substrate material on interface strength and motion. Significant interactions were found between surface treatment and substrate material for both interface strength and motion (P < .05). For titanium, the 20-mm beaded stems had greater interface strength than all other stems (P < .05) and had less motion than the 10-mm plasma-spray and smooth stems (P < .05). For cobalt chrome, the 20-mm beaded stems showed greater interface strength (P < .05) and similar motion (P > .05) to the 20-mm plasma-spray stems (P < .05), which outperformed all other stems (P < .05). Mechanisms of catastrophic failure varied: smooth stems debonded at the stem-cement interface, beaded stems experienced debonding of the beads from the stem, and plasma-spray stems showed loss of frictional force between the surface treatment and cement. Stem surface treatment can enhance ulnar component stability but is dependent on substrate material. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  3. Two-Stage Revision for Infected Total Knee Arthroplasty: Based on Autoclaving the Recycled Femoral Component and Intraoperative Molding Using Antibiotic-Impregnated Cement on the Tibial Side

    PubMed Central

    Lee, Byoung-Joo; Yoon, Seong-Dae

    2015-01-01

    Background The purpose of this study was to determine the degree of infection control and postoperative function for new articulating metal-on-cement spacer. Methods A retrospective study of 19 patients (20 cases), who underwent a two-stage revision arthroplasty using mobile cement prosthesis, were followed for a minimum of 2 years. This series consisted of 16 women and 3 men, having an overall mean age of 71 years. During the first stage of revision, the femoral implant and all the adherent cement was removed, after which it was autoclaved before replacement. The tibial component was removed and a doughy state, antibiotic-impregnated cement was inserted on the tibial side. To achieve joint congruency, intraoperative molding was performed by flexing and extending the knee joint. Each patient was evaluated clinically and radiologically. The clinical assessments included range of motion, and the patients were scored as per the Hospital for Special Surgery (HSS) and Knee Society (KS) criteria. Results The mean range of knee joint motion was 70° prior to the first stage operation and 72° prior to the second stage revision arthroplasty; following revision arthroplasty, it was 113° at the final follow-up. The mean HSS score and KS knee and function scores were 86, 82, and 54, respectively, at the final follow-up. The success rate in terms of infection eradication was 95% (19/20 knees). No patient experienced soft tissue contracture requiring a quadriceps snip. Conclusions This novel technique provides excellent radiological and clinical outcomes. It offers a high surface area of antibiotic-impregnated cement, a good range of motion between first and second stage revision surgery for the treatment of chronic infection after total knee arthroplasty, and is of a reasonable cost. PMID:26330952

  4. Mid-term results of an uncemented femoral stem with modular neck options.

    PubMed

    Benazzo, Francesco; Rossi, Stefano M P; Cecconi, Davide; Piovani, Lucio; Ravasi, Flavio

    2010-01-01

    We prospectively assessed the results of 239 primary total hip replacements performed using a conical stem combined with modular necks of different lengths and inclinations (Modulus System, Lima Corporate San Daniele Del Friuli, Udine, Italia) in 222 patients (50 men, 172 women), undergoing surgery between October 2001 and December 2006 and presenting with anatomical deformities of the proximal femur and/or acetabulum, including developmental dysplasia (DDH), ankylosis, and sequelae of osteotomies or fractures. Such conditions can make hip replacement problematic. The mean age at the time of surgery was 57.6 years (22 ÷ 83). No patients were lost to follow-up. 3 femoral components underwent revision. At a mean of 5 years follow-up the Harris Hip Score showed a significant improvement, increasing from 35 preoperatively to a mean of 96.6. Using Kaplan-Meier analysis the survival rate at 5 years was 98.28%. The Modulus stem showed good mid-term results in terms of survival, as well as clinical and radiographic outcome.

  5. Effect of bone mesenchymal stem cells transplantation on the micro-environment of early osteonecrosis of the femoral head.

    PubMed

    Song, Huanjin; Tao, Li; Wang, Fang; Wang, Weizhuo; Wei, Yongchang; Shen, Wenjun; Zhou, Fuling

    2015-01-01

    Autologous implantation of bone mesenchymal stem cells (BMSCs) has achieved promising clinical efficacy for the treatment of early-stage osteonecrosis of the femoral head (ONFH). However, the underlying mechanisms are not completely elucidated. Here, we investigated the effect of BMSCs on the early ONFH in vitro and in vivo. In co-cultured system, primary BMSCs enhanced the activity and inhibited the apoptosis of primary OB. The concentrations of VEGF and BMP-2 in the co-cultured medium were significantly higher than those without co-culture. Importantly, BMSCs implantation increased OB, capillaries and VEGF and BMP-2 expressions of the necrotic areas of femoral head in the ONFH rabbits. In conclusion, our results indicated that BMSCs treated the early ONFH possibly through increasing OB and capillaries, as well as VEGF and BMP-2 expression in the femoral head. These results provided possible mechanisms for the treatment of early-stage ONFH with BMSCs transplantation.

  6. Adverse reaction to metal bearing leading to femoral stem fractures: a literature review and report of two cases

    PubMed Central

    Al-Azzani, Waheeb A.K.; Iqbal, Hafiz J.; John, Alun

    2016-01-01

    Metal-on-metal (MoM) bearing in total hip replacement (THR) has a high failure rate due to adverse reaction to metal debris (ARMD). There is a spectrum of soft tissue and bony changes in ARMD including muscle necrosis and osteolysis. In our institution, more than 1500 MoM THRs were implanted since 2003. Recently, we have revised significant numbers of these. We report our experience and management of a mode of failure of MoM THR that has been infrequently reported—the distal femoral stem fracture. We report on two patients who presented with worsening pain attributable to fracture of the femoral stem. Severe femoral osteolysis led to loss of proximal stem support and eventual fatigue fracture of the component. Both patients were revised employing a posterior approach. Bone trephine was used to extract a well-fixed distal stem fragment without any windows. Both patients had successful outcome after revision with excellent pain relief and no complications. PMID:26846269

  7. Short-Term Results of Ultra-Short Anatomic vs Ultra-Short Non-Anatomic Proximal Loading Uncemented Femoral Stems.

    PubMed

    Kim, Young-Hoo; Park, Jang-Won; Kim, Jun-Shik

    2017-08-03

    Question arises as to whether rigid fixation of ultra-short anatomic or ultra-short non-anatomic proximal loading uncemented femoral stem can be obtained without diaphyseal stem fixation. The purpose of this study is to compare the short-term clinical results, radiographic results, revision and survival rates, and complication rates of ultra-short anatomic versus ultra-short non-anatomic uncemented femoral stems. This study consisted of 50 patients (56 hips) in the ultra-short anatomic uncemented stem group (mean age 61.4 ± 14.7 years) and 50 patients (56 hips) in the ultra-short non-anatomic uncemented stem group (mean age 59.5 ± 15.2 years). The mean follow-up was 3.4 years (range 3-4) in the ultra-short anatomic stem group and 3.5 years (range 3-4) in the ultra-short non-anatomic stem group. At the final follow-up, the mean Harris hip scores (92 vs 93 points), Western Ontario and McMaster Universities Osteoarthritis scores (16 vs 15 points), University of California at Los Angeles activity scores (6.5 vs 6.8 points), the incidence of thigh pain (0% vs 4%), revision rates (0% vs 4%), aseptic loosening rate (0% vs 2%), and complication rates (2% vs 4%) were not significantly different between 2 groups. Both ultra-short anatomic and ultra-short non-anatomic proximal loading uncemented femoral stems obtained rigid fixation without diaphyseal stem fixation in the short-term follow-up. This finding suggests that an ultra-short anatomic uncemented femoral stem can be replaced with an ultra-short non-anatomic uncemented stem to reduce inventory of the femoral stems, and consequently reduce manufacturing and delivery cost of these femoral stems. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. 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...

  9. 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...

  10. 21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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...

  11. Reduced femoral component subsidence with improved impaction grafting at revision hip arthroplasty.

    PubMed

    Howie, D W; Callary, S A; McGee, M A; Russell, N C; Solomon, L B

    2010-12-01

    Despite stem subsidence being a major complication of femoral impaction bone grafting in cemented revision hip arthroplasty, few studies have distinguished subsidence at the prosthesis-cement interface from that at the cement-bone interface. It is unknown how technique developments intended to improve the procedure influence stability of the stem. We used a sensitive technique to measure subsidence of a cemented polished collarless double-taper stem at each interface after femoral impaction grafting and compared subsidence, radiographic loosening, complications, and reoperations over three series of hips defined by technique developments. Three series were defined: Series 1 (n = 23, irradiated allograft), Series 2 (n = 12, double-washed, size-profiled graft, nonirradiated bone, long stems as required), and Series 3 (n = 21, modular tamps). Stem subsidence was analyzed with Ein Bild Röntgen Analyse software. Radiographic loosening, complications, and reoperations were also determined. The median subsidence at 12 months for Series 1, 2, and 3 were 2.1, 0.5, and 0.7 mm at the prosthesis-cement interface and 1.3, 0.1, and 0.1 mm at the cement-bone interface. There were two postoperative Vancouver B periprosthetic fractures in Series 1, four hips were revised for loosening in Series 1, and there were no fractures or loosening in Series 2 and 3 at minimum 2 years' followup. There were no surviving hips radiographically classified as possibly or probably loose. Evolution in techniques of femoral impaction grafting in this study were associated with reduced subsidence of the stem at both the prosthesis-cement interface and cement-bone interface when compared to the original series. Concurrent with reduced stem subsidence was the absence of periprosthetic fracture, radiographic loosening, and complications requiring rerevision.

  12. [Is instillation of bone marrow stem cells at the time of core decompression useful for osteonecrosis of the femoral head?].

    PubMed

    Cabrolier, Jorge; Molina, Marcelo

    2016-03-24

    Osteonecrosis of the femoral head leads to degeneration of the head and finally to osteoarthritis of the hip. Decompression is the most widely used treatment, but its effectiveness is limited. It has been proposed instillation of stem cells in addition to decompression, would lead to better results. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified two systematic reviews including two randomized trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded instillation of bone marrow stem cells at the time of core decompression probably slows progression to osteoarthritis of the hip in patients with osteonecrosis of the femoral head and might reduce the need of subsequent surgeries. It is unclear whether it has any effect on the functionality because the certainty of the evidence is very low.

  13. Similar effect of stem geometry on radiological changes with 2 types of cemented straight stem: The Müller stem and the Virtec stem compared in 711 hips.

    PubMed

    Clauss, Martin; Bolliger, Lilianna; Brandenberger, Daniel; Ochsner, Peter E; Ilchmann, Thomas

    2016-01-01

    There are 2 basic principles in cemented stem fixation: shape-closed and force-closed. We investigated 2 shape-closed straight stems, the Müller (MSS) and the Virtec (VSS), which differ only in geometrical cross section, to determine whether the difference in stem shape would affect the radiological results or long-term survival. We included 711 hips (in 646 patients) that were operated on between July 1996 and July 2003. Patients randomly received either an MSS (n = 356) or a VSS (n = 355) and were followed prospectively. Radiographs taken at a follow-up of > 10 years were analyzed for osteolysis. Kaplan-Meier (KM) survival analysis was performed using various endpoints. We also performed Cox regression analysis to identify risk factors for aseptic loosening and osteolysis of the stem. After 10 years, KM survival with "revision of any component for any reason" was 92% (95% CI: 88-95) for the MSS and 95% (CI: 92-97) for the VSS (p = 0.1). With "revision for aseptic loosening of the stem" as the endpoint, KM survival was 96% (CI: 9-98) for the MSS and 98% (CI: 97-100) for the VSS (p = 0.2). Cox regression showed that none of the risk factors analyzed were independent regarding aseptic loosening of the stem or regarding osteolysis. The MSS and the VSS showed excellent survival for aseptic loosening after 10 years. For the 2 different stem designs, we did not find any independent risk factors for aseptic loosening or development of osteolysis.

  14. Successful femoral reconstruction with a fluted and tapered modular distal fixation stem in revision total hip arthroplasty.

    PubMed

    Skyttä, E T; Eskelinen, A; Remes, V

    2012-01-01

    Early results of fluted and tapered distal fixation stems used in reconstruction of deficient femora in femoral revision arthroplasty have been successful in small series. We evaluated the survival of the LINK MP Reconstruction Hip Stem and factors associated with survival using data from a nation-wide arthroplasty register. 408 femoral revisions using LINK MP Reconstruction Hip Stem were performed during 1994 to 2007. The mean age of the patients was 72.5 (range: 36-93) years and 63% were performed in women. Kaplan-Meier analysis and the Cox regression model were used for the survival analysis. The effects of age, sex and diagnoses were also studied. The 9-year overall survivorship for the LINK MP Reconstruction Hip Stem was 75% (95% CI 70-80). Aseptic loosening was rare; the 9-year revision rate for aseptic loosening was only 3%, which coincides with earlier reports with shorter folllow-up. The most common reason for re-revision was dislocation of the prosthesis with or without malposition of the socket (67%). Indication for revision strongly affected the survival rate with revisions for dislocation having an over 3-fold and revisions for infection a 3-fold relative risk for re-revision compared to revisions for aseptic loosening. Increasing age slightly decreased the risk of re-revision but sex did not affect the survival. Based on our findings, we conclude LINK MP Reconstruction Hip Stem, as an example of a fluted and tapered distal fixation stem, appears to solve many problems with implant fixation in femoral revisions. High number of dislocations suggests that special attention should be paid to correct center of rotation, to correct implant positioning and to need of constrained implants in case of deficient abductor mechanism.

  15. Effects of Prosthesis Stem Tapers on Stress Distribution of Cemented Hip Arthroplasty

    SciTech Connect

    Abdullah, Abdul Halim; Nor, Mohd Asri Mohd; Saman, Alias Mohd; Tamin, Mohd Nasir; Kadir, Mohammed Rafiq Abdul

    2010-10-15

    Aseptic loosening effects are critical issues in encouraging long term stability of cemented hip arthroplasty. Stress shielding is believed to be an important factor that contributes to the aseptic loosening problems. The numerous changes in the prosthesis stem design are intended to minimize the stress shielding and aseptic loosening problems and to improve the long term performance of the implants. In this study, the stress distribution in cemented hip arthroplasty is established using finite element method. The taper of the prosthesis is designed to be 3 deg. at anterior/posterior, 3 deg. at medial/lateral and 10 deg. from wide lateral to narrow medial. Major muscle loads and contact forces are simulated for walking (toe-off phase) and stair climbing load cases. Effects of prosthesis stem tapers on the resulting stress distribution are investigated. Results show that compressive stress dominates in the medial plane while tensile stress in the lateral plane of the femur. The corresponding stress levels of intact femur for walking and stair-climbing load cases are 22 and 29 MPa, respectively. The magnitude of Tresca stress for the THA femur in stair-climbing load case remains higher in the region of 85 MPa while the walking load case induces around 40 MPa. The stress range in the straight and single taper stem prosthesis is lower than 260 MPa, while localized Tresca stress is in the order of the yield strength of Ti-6Al-4V alloy for double and triple taper stem design.

  16. Effects of Prosthesis Stem Tapers on Stress Distribution of Cemented Hip Arthroplasty

    NASA Astrophysics Data System (ADS)

    Abdullah, Abdul Halim; Nor, Mohd Asri Mohd; Saman, Alias Mohd; Tamin, Mohd Nasir; Kadir, Mohammed Rafiq Abdul

    2010-10-01

    Aseptic loosening effects are critical issues in encouraging long term stability of cemented hip arthroplasty. Stress shielding is believed to be an important factor that contributes to the aseptic loosening problems. The numerous changes in the prosthesis stem design are intended to minimize the stress shielding and aseptic loosening problems and to improve the long term performance of the implants. In this study, the stress distribution in cemented hip arthroplasty is established using finite element method. The taper of the prosthesis is designed to be 3° at anterior/posterior, 3° at medial/lateral and 10° from wide lateral to narrow medial. Major muscle loads and contact forces are simulated for walking (toe-off phase) and stair climbing load cases. Effects of prosthesis stem tapers on the resulting stress distribution are investigated. Results show that compressive stress dominates in the medial plane while tensile stress in the lateral plane of the femur. The corresponding stress levels of intact femur for walking and stair-climbing load cases are 22 and 29 MPa, respectively. The magnitude of Tresca stress for the THA femur in stair-climbing load case remains higher in the region of 85 MPa while the walking load case induces around 40 MPa. The stress range in the straight and single taper stem prosthesis is lower than 260 MPa, while localized Tresca stress is in the order of the yield strength of Ti-6Al-4V alloy for double and triple taper stem design.

  17. Bond strength analysis of the bone cement- stem interface of hip arthroplasties.

    PubMed

    Zhang, Lan-Feng; Ge, Shi-Rong; Liu, Hong-Tao; Guo, Kai-Jin; Han, Shu-Yang; Qi, Juan-Yan

    2014-02-01

    To study and establish the preliminary linear and modified models for the interface shear mechanics performance between implant and bone cement and to explore its damage significance. The loosening research between artificial hip joint prosthesis stem and bone cement interface performance can be evaluated by the push-in test. Based on the debonding performance test, the analytical expressions of the average load and displacement from the debonding failure and splitting failure process were deduced and determined. The correlations of the expressions of the average load-displacement and statistical experimental data were analyzed. It demonstrated that the interface debonding failure mechanical model could be characterized as interface bond strength mechanical performance. Based on analysis of models and experimental data by the three statistical analysis methods, the results indicated the modified model could be better represented by the interfacial debonding strength properties. The bond stress τ and relative sliding s distribution along the embedment regional were coupling affected by both pressure arch effect and shear lag effect in bone cement. Two stress peaks of implant have been found at the distance from 0.175La loading tip to 0.325La free tip, which also verified the early loosening clinical reports for the proximal and latter region. As the bone cement arch effect, the bond stress peak tend to move to the free tip when the debonding failure would be changed into the splitting failure, which presents a preliminary study on the mechanism of early debonding failure for the stem-cement interface. Functional models of the stem-bone cement interfacial debonding failure are developed to analyze the relevant mechanism. The different locational titanium alloy stress, and the interfacial bond stress and the relative slides are evaluated to acquire a guide of the different positions of interfacial damage. The coupling effect which is original from the pressure arch

  18. Effect of femoral canal shape on mechanical stress distribution and adaptive bone remodelling around a cementless tapered-wedge stem.

    PubMed

    Oba, M; Inaba, Y; Kobayashi, N; Ike, H; Tezuka, T; Saito, T

    2016-09-01

    In total hip arthroplasty (THA), the cementless, tapered-wedge stem design contributes to achieving initial stability and providing optimal load transfer in the proximal femur. However, loading conditions on the femur following THA are also influenced by femoral structure. Therefore, we determined the effects of tapered-wedge stems on the load distribution of the femur using subject-specific finite element models of femurs with various canal shapes. We studied 20 femurs, including seven champagne flute-type femurs, five stovepipe-type femurs, and eight intermediate-type femurs, in patients who had undergone cementless THA using the Accolade TMZF stem at our institution. Subject-specific finite element (FE) models of pre- and post-operative femurs with stems were constructed and used to perform FE analyses (FEAs) to simulate single-leg stance. FEA predictions were compared with changes in bone mineral density (BMD) measured for each patient during the first post-operative year. Stovepipe models implanted with large-size stems had significantly lower equivalent stress on the proximal-medial area of the femur compared with champagne-flute and intermediate models, with a significant loss of BMD in the corresponding area at one year post-operatively. The stovepipe femurs required a large-size stem to obtain an optimal fit of the stem. The FEA result and post-operative BMD change of the femur suggest that the combination of a large-size Accolade TMZF stem and stovepipe femur may be associated with proximal stress shielding.Cite this article: M. Oba, Y. Inaba, N. Kobayashi, H. Ike, T. Tezuka, T. Saito. Effect of femoral canal shape on mechanical stress distribution and adaptive bone remodelling around a cementless tapered-wedge stem. Bone Joint Res 2016;5:362-369. DOI: 10.1302/2046-3758.59.2000525. © 2016 Yutaka et al.

  19. Effect of femoral canal shape on mechanical stress distribution and adaptive bone remodelling around a cementless tapered-wedge stem

    PubMed Central

    Oba, M.; Kobayashi, N.; Ike, H.; Tezuka, T.; Saito, T.

    2016-01-01

    Objectives In total hip arthroplasty (THA), the cementless, tapered-wedge stem design contributes to achieving initial stability and providing optimal load transfer in the proximal femur. However, loading conditions on the femur following THA are also influenced by femoral structure. Therefore, we determined the effects of tapered-wedge stems on the load distribution of the femur using subject-specific finite element models of femurs with various canal shapes. Patients and Methods We studied 20 femurs, including seven champagne flute-type femurs, five stovepipe-type femurs, and eight intermediate-type femurs, in patients who had undergone cementless THA using the Accolade TMZF stem at our institution. Subject–specific finite element (FE) models of pre- and post-operative femurs with stems were constructed and used to perform FE analyses (FEAs) to simulate single-leg stance. FEA predictions were compared with changes in bone mineral density (BMD) measured for each patient during the first post-operative year. Results Stovepipe models implanted with large-size stems had significantly lower equivalent stress on the proximal-medial area of the femur compared with champagne-flute and intermediate models, with a significant loss of BMD in the corresponding area at one year post-operatively. Conclusions The stovepipe femurs required a large-size stem to obtain an optimal fit of the stem. The FEA result and post-operative BMD change of the femur suggest that the combination of a large-size Accolade TMZF stem and stovepipe femur may be associated with proximal stress shielding. Cite this article: M. Oba, Y. Inaba, N. Kobayashi, H. Ike, T. Tezuka, T. Saito. Effect of femoral canal shape on mechanical stress distribution and adaptive bone remodelling around a cementless tapered-wedge stem. Bone Joint Res 2016;5:362–369. DOI: 10.1302/2046-3758.59.2000525. PMID:27601435

  20. The impact of proximal femoral morphology on failure strength with a mid-head resection short-stem hip arthroplasty.

    PubMed

    Olsen, Michael; Al Saied, Mohamed; Morison, Zachary; Sellan, Michael; Waddell, James P; Schemitsch, Emil H

    2014-12-01

    Mid-head resection short-stem hip arthroplasty is a conservative alternative to conventional total hip replacement and addresses proximal fixation challenges in patients not suitable for hip resurfacing. It is unclear whether proximal femoral morphology impacts the ultimate failure load of mid-head resection implanted femurs, thus the aim of this study was to investigate the effect of native neck-shaft angle (NSA) and coronal implant alignment on proximal femoral strength. In total, 36 synthetic femurs with two different proximal femoral morphologies were utilized in this study. Of them, 18 femurs with a varus NSA of 120° and 18 femurs with a valgus NSA of 135° were each implanted with a mid-head resection prosthesis. Femurs within the two different femoral morphology groups were divided into three equal coronal implant alignment groups: 10° valgus, 10° varus or neutral alignment. Prepared femurs were tested for stiffness and to failure in axial compression. There was no significant difference in stiffness nor failure load between femurs implanted with valgus-, varus- or neutrally aligned implants in femurs with a NSA of 120° (p = 0.396, p = 0.111, respectively). Femurs implanted in valgus orientation were significantly stiffer and failed at significantly higher loads than those implanted in varus alignment in femurs with a NSA of 135° (p = 0.001, p = 0.007, respectively). A mid-head resection short-stem hip arthroplasty seems less sensitive to clinically relevant variations of coronal implant alignment and may be more forgiving upon implantation in some femoral morphologies, however, a relative valgus component alignment is recommended. © IMechE 2014.

  1. 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.

  2. Femoral deficiency reconstruction using a hydroxyapatite-coated locked modular stem. A series of 43 total hip revisions.

    PubMed

    Philippot, R; Delangle, F; Verdot, F-X; Farizon, F; Fessy, M-H

    2009-04-01

    We report a continuous prospective series of patients operated on for total hip prosthesis femoral component loosening involving a bone defect. Reconstruction was performed using a hydroxyapatite-coated locked modular stem. The study's objective was to assess medium term clinical and X-ray results obtained with this original concept. The patients included received a REEF (DePuy) femoral implant for aseptic loosening or loosening associated with a periprosthetic fracture. Implantation was systematically accompanied by an extended trochanteric osteotomy (ETO). Patients were followed up prospectively by clinical and X-ray examination. Their loosening was graded at inclusion according to Vives' classification as revised by SOFCOT in 1999. Analysis focused on actuarial implant survivorship, dislocation and the bone/implant interface. Forty-three hips were included: mean follow-up was 58.2 months (12-92) and mean age at surgery was 72.4 years (37-94). The main indications were severe bone loss rated grade III (n=15) or IV (n=16) according to the SOFCOT classification. There was one long-term failure, involving implant fracture secondary to nonunion of the femoral shaft. Mean Postel and Merle d'Aubigné (PMA) clinical assessment score increased from six preoperatively to 14.5 at end of follow-up. X-ray analysis found no stem migration by end of follow-up. There was consistent consolidation of the ETO around the stem, except in one case of stem fracture which evolved into tight nonunion. In terms of metaphyseal integration, five patients showed radiolucency without evolution over follow-up, and eight had severe calcar cortical atrophy at end of follow-up. Mean 5-year actuarial survivorship was 97.7+/-2.3%, with a 2% incidence of dislocation. The complications rate was low, and results were comparable with those reported in the literature. The study confirmed the interest of the extended trochanteric osteotomy exposure and the effectiveness of the hydroxyapatite

  3. Hemi-arthroplasty of the hip followed by ipsilateral fracture of the femoral shaft.

    PubMed

    Barfod, G; Steen Jensen, J; Hansen, D; Larsen, E; Menck, H; Olsen, B; Rosenklint, A

    1986-03-01

    In a series of 74 ipsilateral fractures of the femoral shaft in relation to hemi-arthroplasties, treatment by a cemented long-stem total hip replacement was found to be superior to conservative treatment or internal fixation without removal of the prosthesis. Acceptable clinical results were obtained in 89 per cent of these cases.

  4. Modified metaphyseal-loading anterolaterally flared anatomic femoral stem: five- to nine-year prospective follow-up evaluation and results of three-dimensional finite element analysis.

    PubMed

    Kokubo, Yasuo; Uchida, Kenzo; Oki, Hisashi; Negoro, Kohei; Nagamune, Kouki; Kawaguchi, Shogo; Takeno, Kenichi; Yayama, Takafumi; Nakajima, Hideaki; Sugita, Daisuke; Yoshida, Ai; Baba, Hisatoshi

    2013-02-01

    We have designed a proximal-fitting, anterolaterally flared, arc-deposit hydroxyapatite-coated anatomical femoral stem (FMS-anatomic stem; KYOCERA Medical, Osaka, Japan) for cementless total hip arthroplasty (THA) for Japanese patients with dysplastic hip osteoarthritis, using a nonlinear three-dimensional finite element analysis simulating loading conditions. The Anatomic Fit stem was modified in the region of the arc-sprayed surface, to allow more proximal appearance of spot welds. The aim of the present study was to analyze the clinical and radiographic outcomes of patients who underwent THA using this stem. We reviewed 73 consecutive patients (79 hips; 13 men 16 hips; 60 women 63 hips; age at surgery, 57.6 years, range, 35-78) who underwent cementless THA using the Anatomic Fit stem, at a follow-up period of 7.1 years (range, 5.1-9.4). Harris Hip score improved from 40.7 ± 17.1 before surgery to 91.0 ± 5.2 points at follow-up. The 7.1-year stem survival rate was 100%. Radiographs at follow-up confirmed the stability of the femoral stems within the femoral canal in all cases, with sufficient bone ingrowth. None of the patients had subsidence of the stem exceeding 2.0 mm within the femoral canal or changes in varus or valgus position of more than 2.0°. The Anatomic Fit stem provided excellent results. The nonlinear three-dimensional finite element analysis demonstrated that the stem-bone relative motion was 10 µm at the proximal end of the stem and proximal load transfer. Our analysis confirmed reduced radiolucency around the stem, minimal subsidence, appropriate stress shielding, and promising medium-term stability within the femoral canal.

  5. In vitro assessment of Function Graded (FG) artificial Hip joint stem in terms of bone/cement stresses: 3D Finite Element (FE) study.

    PubMed

    Al-Jassir, Fawzi F; Fouad, H; Alothman, Othaman Y

    2013-01-16

    Stress shielding in the cemented hip prosthesis occurs due to the mismatching in the mechanical properties of metallic stem and bone. This mismatching in properties is considered as one of the main reasons for implant loosening. Therefore, a new stem material in orthopedic surgery is still required. In the present study, 3D finite element modeling is used for evaluating the artificial hip joint stem that is made of Function Graded (FG) material in terms of joint stress distributions and stem length. 3D finite element models of different stems made of two types of FG materials and traditional stems made of Cobalt Chromium alloy (CoCrMo) and Titanium alloy (Ti) were developed using the ANSYS Code. The effects on the total artificial hip joint stresses (Shear stress and Von Mises stresses at bone cement, Von Mises stresses at bone and stem) due to using the proposed FG materials stems were investigated. The effects on the total artificial hip joint system stresses due to using different stem lengths were investigated. Using FG stem (with low stiffness at stem distal end and high stiffness at its proximal end) resulted in a significant reduction in shear stress at the bone cement/stem interface. Also, the Von Mises stresses at the bone cement and stem decrease significantly when using FG material instead of CoCrMo and Ti alloy. The stresses' distribution along the bone cement length when using FG material was found to be more uniform along the whole bone cement compared with other stem materials. These more uniform stresses will help in the reduction of the artificial hip joint loosening rate and improve its short and long term performance. FE results showed that using FG stem increases the resultant stresses at the femur bone (reduces stress shielding) compared to metallic stem. The results showed that the stem length has significant effects on the resultant shear and Von Mises stresses at bone, stem and bone cement for all types of stem materials.

  6. Deformation pattern and load transfer of an uncemented femoral stem with modular necks. An experimental study in human cadaver femurs.

    PubMed

    Enoksen, Cathrine H; Gjerdet, Nils R; Klaksvik, Jomar; Arthursson, Astvaldur J; Schnell-Husby, Otto; Wik, Tina S

    2016-02-01

    Modular necks in hip arthroplasty allow variations in neck-shaft angles, neck version and neck lengths and have been introduced to improve accuracy when reconstructing the anatomy and hip joint biomechanics. Periprosthetic bone resorption may be a consequence of stress shielding in the proximal femur after implantation of a femoral stem. The purpose of this study was to investigate the deformation pattern and load transfer of an uncemented femoral stem coupled to different modular necks in human cadaver femurs. A cementless femoral stem was implanted in twelve human cadaver femurs and tested in a hip simulator corresponding to single leg stance and stair climbing activity with patient-specific loading. The stems were tested with four different modular necks; long, short, retro and varus. The long neck was used as reference in statistical comparisons, as it can be considered the "standard" neck. The deformation of bone during loading was measured by strain gauge rosettes at three levels of the proximal femur on the medial, lateral and anterior side. The cortical strains were overall reduced on the medial and lateral side of femur, for all implants tested, and in both loading conditions compared to the unoperated femur. Although there were statistical significant differences between the necks, the results did not show a consistent pattern considering which neck retained or lost most strain. In general the differences were small, with the highest significant difference between the necks of 3.23 percentage points. The small differences of strain between the modular necks tested in this study are not expected to influence bone remodeling in the proximal femur. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Total Hip Arthroplasty Using a Short-Stemmed Femoral Component in the Presence of a Long Dynamic Condylar Screw Osteosynthesis Plate

    PubMed Central

    Buttaro, Martin; Piuzzi, Nicolas; Comba, Fernando; Zanotti, Gerardo; Piccaluga, Francisco

    2014-01-01

    We present a potential indication of a short-stemmed femoral component in a patient with multiple comorbidities presenting with hip posttraumatic osteoarthritis and a long dynamic condylar screw osteosynthesis plate. Removal of the plate and implantation of a long stem would have been related to a much longer operative time and potential local or systemic complications. PMID:25349758

  8. Treatment of Femoral Head Necrosis With Bone Marrow Mesenchymal Stem Cells Expressing Inducible Hepatocyte Growth Factor.

    PubMed

    Pan, Zhi-Min; Zhang, Yu; Cheng, Xi-Gao; Gao, Gui-Cheng; Wang, Xiang-Rui; Cao, Kai

    Our study assessed the effect of bone marrow mesenchymal stem cells (BMSCs) expressing inducible hepatocyte growth factor (HGF) on the recovery of femoral head necrosis (FHN). BMSCs were isolated by density gradient centrifugation. A recombinant AdTRE-HGF was constructed as the response plasmid and Adeno-X Tet-on as the regulator vector. The regulator and the response vectors were coinfected into BMSCs and induced at 0, 200, 500, 1000, and 1200 ng/mL doxycycline (Dox). After 3 days, the concentration of HGF was determined using enzyme-linked immunosorbent assay. Forty rabbits were selected to establish the FHN model and divided into 4 experimental groups. After the rabbits were killed by ketamine overdose, the restoration of FHN was assessed. The distribution of HGF-positive cells was observed by immunohistochemical method. Enzyme-linked immunosorbent assay results showed that 1000 ng/mL Dox induced the highest HGF expression level, even higher than the 1200 ng/mL Dox induction. The highest osteonecrosis incidence and empty lacunae percentage were found in group A compared with all the other groups (all P < 0.05). Furthermore, dramatically lower osteonecrosis incidence and empty lacunae percentage were found in group C compared with those of groups B and D (all P < 0.05). A significantly higher level of HGF protein was detected in group C compared with the other groups (all P < 0.05). Our study successfully developed the AdTRE-HGF, a recombinant adenovirus carrying HGF gene, for high expression of HGF in BMSCs. Importantly, introduction of BMSCs expressing HGF successfully produced the desired therapeutic effect in reversing FHN, in a Dox-dependent manner.

  9. Long Term Survivorship of a Severely Notched Femoral Stem after Replacing the Fractured Ceramic head with a Cobalt-Chromium Head

    PubMed Central

    Panagopoulos, Andreas; Tatani, Irini; Megas, Panagiotis

    2016-01-01

    Background: Although ceramic head fracture occurs infrequently today, in the event of a fracture, the resulting revision surgery can prove very challenging, since the ceramic particles lodge into the surrounding soft tissue and can cause rapid implant failure Case Presentation: A case of long term survivorship of a severed notched femoral stem after replacing the fractured femoral head with a cobalt-chromium one is reported in a 40-year old woman with hip dysplasia who underwent an uncomplicated total hip arthroplasty. The incident of ceramic femoral head fracture occurred 14 months postoperatively without reporting any significant trauma. Intraoperative findings at revision were a multifragmented femoral head and a damaged polyethylene insert along with diffuse metallosis and excessive wear of the cone of the stem. Both the stem and the acetabular component were stable. After removal of ceramic fragments, metallotic tissue excision and careful lavage of the joint, the inlay was replaced by a similar one and a cobalt-chromium femoral head was placed to the existing notched taper of the firmly incorporated stem. At the 13th year follow up examination, the patient had no pain, used no walking aids, and had normal activity with no signs of wearing or loosening in the plain x-rays. Conclusion: Despite current recommendations of using ceramic femoral heads in cases of fracture or to revise the severely damaged stems we were able to provide a long term survivorship up to 13 years postoperatively of a cobalt-chromium femoral head applied to a severe damaged stem. PMID:28217203

  10. Transplantation of hypoxia preconditioned bone marrow mesenchymal stem cells enhances angiogenesis and osteogenesis in rabbit femoral head osteonecrosis.

    PubMed

    Fan, Lihong; Zhang, Chen; Yu, Zefeng; Shi, Zhibin; Dang, Xiaoqian; Wang, Kunzheng

    2015-12-01

    Osteonecrosis of the femoral head may be a disease resulting from abnormal proliferation or differentiation of mesenchymal stem cells. The present investigation explored the novel strategy of hypoxia-preconditioned BMMSCs to reverse the impairment of osteonecrosis BMMSCs and enhance the therapeutic potential of hypoxia-treated BMMSC transplantation. BMMSCs from the anterior superior iliac spine region of osteonecrosis rabbit were cultured under 20% O2 or 2% O2 conditions. Normal BMMSCs were cultured under 20% O2 condition as control. Growth factors secreted were examined by enzyme-linked immunosorbent assay. 20% O2 or 2% O2 BMMSCs were injected into the femoral head of rabbits after core decompression. Cell viability and apoptosis were assessed in vitro, and TUNEL staining of the femoral head was analyzed after transplantation. Angiogenesis (capillary-like structure formation, CD31 immunohistochemical staining and ink infusion angiography) and osteogenesis (Alizarin red-S staining, micro-CT scanning and OCN immunohistochemical staining) tests were conducted as well. 2% O2 exposure up-regulated growth factor secretion in BMMSCs. Apoptosis in 2% O2 group was lower when compared with that in 20% O2 osteonecrosis group. Cell viability in 2% O2 was significantly higher when compared with that in 20% O2 osteonecrosis group. Growth factor secretion, cell viability, apoptosis, capillary-like structure formation, Alizarin red-S staining, and ALP staining showed no difference between the 2% O2 BMMSC and normal BMMSC groups. Transplantation of 2% O2 versus 20% O2 mesenchymal stem cells after core decompression resulted in an increase in angiogenesis function and a decrease in local tissue apoptosis. Our study also found that osteogenesis function was improved after hypoxic stem cell transplantation. Hypoxic preconditioning of BMMSCs is an effective means of reversing the impairment of osteonecrosis BMMSCs, promoting their regenerative capability and therapeutic potential for

  11. Impact of intraprosthetic drilling on the strength of the femoral stem in periprosthetic fractures: A finite element investigation.

    PubMed

    Brand, Stephan; Bauer, Michael; Petri, Maximilian; Schrader, Julian; Maier, Hans J; Krettek, Christian; Hassel, Thomas

    2016-07-01

    Treatment of periprosthetic femur fractures after total hip arthroplasty remains a major challenge in orthopedic surgery. Recently, a novel surgical technique using intraprosthetic screw fixation has been suggested. The purpose of this study was to evaluate the influence of drilling the femoral hip stem on integrity and strength of the implant. The hypothesis was that intraprosthetic drilling and screw fixation would not cause the load limit of the prosthesis to be exceeded and that deformation would remain within the elastic limit. A sawbone model with a conventional straight hip stem was used and a Vancouver C periprosthetic fracture was created. The fracture was fixed with a nine-hole less invasive stabilization system plate with two screws drilled and inserted through the femoral hip stem. Three different finite element models were created using ANSYS software. The models increased in complexity including joint forces and stress risers from three different dimensions. A variation of drilling positions was analyzed. Due to the complexity of the physiological conditions in the human femur, the most complex finite element model provided the most realistic results. Overall, significant changes in the stresses to the prosthesis caused by the drilling procedure were observed. While the stresses at the site of the bore hole decreased, the load increased in the surrounding stem material. This effect is more pronounced and further the holes were apart, and it was found that increasing the number of holes could counteract this. The maximum load was still found to be in the area of the prosthesis neck. No stresses above the load limit of titanium alloy were detected. All deformations of the prosthesis stem remained in the elastic range. These results may indicate a potential role for intraprosthetic screw fixation in the future treatment of periprosthetic femur fractures.

  12. Mechanical assessment of a hip joint stem model made of a PEEK/carbon fibre composite under compression loading.

    PubMed

    Dworak, Michał; Błażewicz, Stanisław

    2016-01-01

    The aim of the work was to manufacture a composite stem model consisting of carbon fibres (CF) and polyether ether ketone (PEEK) and to perform the surface strain and stress distributions in the stem-femoral bone model under compression loading. Composite stems differing in elasticity were prepared. Three types of composite stems having different arrangements of carbon fibre reinforcements (carbon fibre roving, carbon fibre sleeves and their combinations) in the polymer matrix were made. The stems were cementless fixed in the femoral bone model channel or with the use of the polymer bone cement (PMMA). Mechanical behaviour of composite stems under compression loading was compared with a metallic stem by strain gauge measurements at different parts of stem/bone model systems. The values of stresses in the proximal part of the bone model for cemented and cementless fixations of the composite stem in the femoral bone channel were higher than those noted for the metallic stem. The increase in proximal bone stress was almost similar for both types of fixation of composite stems, i.e., cemented and cementless fixed stems. The optimal range of mechanical stiffness, strengths and work up to fracture was obtained for composite stem made of carbon fibre sleeves and carbon fibres in the form of roving. Depending on the elasticity of the composite stem model, an increase in the stress in the proximal part of femoral bone model of up to 40% was achieved in comparison with the metallic stem.

  13. Angiogenesis and bone regeneration by allogeneic mesenchymal stem cell intravenous transplantation in rabbit model of avascular necrotic femoral head.

    PubMed

    Li, Zhanghua; Liao, Wen; Zhao, Qiang; Liu, Ming; Xia, Wei; Yang, Yi; Shao, Ningsheng

    2013-07-01

    To explore the feasibility of allogeneic mesenchymal stem cells (MSCs) transplanted intravenously for angiogenesis and bone repair in a rabbit model of avascular necrosis of femoral head (ANFH). Forty-five rabbits were randomized into three groups: a blank control group (without treatment), a necrotic control group (ANFH induced but without therapy), and an MSC transplantation group (ANFH induced and treated with MSC transplantation). The biopsies, blood sampling, and imaging examinations were performed on each animal at different time points (2, 4, and 6 wk). To monitor angiogenesis and bone repair progress, examinations included real-time polymerase chain reaction, Western blot analysis, x-ray, computed tomography, Masson trichrome staining, picrosirius red staining, and immunohistochemical staining. Necrosis and bone collapse were observed in bilateral femoral heads of necrotic rabbits of the necrotic control group, whereas the femoral head morphology was generally restored in the MSC transplantation group. The mRNA levels of Cbfa1, BMP, VEGF, and OPN in bone tissue were significantly higher in the MSC transplantation group than in the necrotic control group. In addition, the total protein amount of Cbfa1 in the MSC transplantation group was also significantly higher than that in the necrotic control group (P < 0.05). Intravenous transplantation of allogeneic MSCs can promote vascular and bone regeneration in the necrotic region of the femoral head in a rabbit model of ANFH. The results of our study suggest that the intravenous transplantation of MSCs could be a potential and minimally invasive treatment option for ANFH patients. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Clinical and Radiologic Outcomes of a Fully Hydroxyapatite-Coated Femoral Revision Stem: Excessive Stress Shielding Incidence and its Consequences.

    PubMed

    Sanli, Ilknur; Arts, Jacobus Johannes Christiaan; Geurts, Jan

    2016-01-01

    Stress shielding remains a concern in total hip arthroplasty. The consequences of stress shielding in hydroxyapatite-coated femoral component revisions were evaluated in a prospective cohort study. A total of 106 patients operated on by revision total hip arthroplasty were identified. Sixty-three patients were eligible for clinical and radiologic assessment of osseointegration, bone remodeling, and stress shielding. Five patients showed evidence of excessive stress shielding. One patient experienced a periprosthetic fracture. No adverse events occurred in the remaining patients with a low rate of thigh pain and reliable osseointegration. This is the only available study concerning mid- to long-term consequences of excessive stress shielding in hydroxyapatite-coated revision stems. We advocate surgeons using these stems to remain vigilant and be aware of possible stress shielding side effects.

  15. Femoral impaction bone grafting in revision hip arthroplasty: 705 cases from the originating centre.

    PubMed

    Wilson, M J; Hook, S; Whitehouse, S L; Timperley, A J; Gie, G A

    2016-12-01

    Femoral impaction bone grafting was first developed in 1987 using morselised cancellous bone graft impacted into the femoral canal in combination with a cemented, tapered, polished stem. We describe the evolution of this technique and instrumentation since that time. Between 1987 and 2005, 705 revision total hip arthroplasties (56 bilateral) were performed with femoral impaction grafting using a cemented femoral stem. All surviving patients were prospectively followed for a mean of 14.7 years (9.8 to 28.3) with no loss to follow-up. By the time of the final review, 404 patients had died. There were 76 further revisions (10.8%) involving the stem; seven for aseptic loosening, 23 for periprosthetic fracture, 24 for infection, one for malposition, one for fracture of the stem and 19 cement-in-cement exchanges of the stem during acetabular revision. The 20-year survival rate for the entire series was 98.8% (95% confidence interval (CI) 97.8 to 99.8) with aseptic loosening as the endpoint, and 87.7% (95% CI 82.8 to 92.6) for revision for any reason. Survival improved with the evolution of the technique, although this was not statistically significant due to the overall low rate of further revision. This is the largest series of revision total hip arthroplasties with femoral impaction grafting, and the results support the continued use of this technique. Cite this article: Bone Joint J 2016;98-B:1611-19. ©2016 The British Editorial Society of Bone & Joint Surgery.

  16. Anti-platelet drugs in patients with femoral neck fractures undergoing cemented hip hemiarthroplasty surgery. A study of complications and mortality.

    PubMed

    Agudo Quiles, M; Sanz-Reig, J; Alcalá-Santaella Oria de Rueca, R

    2015-01-01

    To assess complications and factors predicting one-year mortality in patients on antiplatelet agents presenting with femoral neck fractures undergoing hip hemiarthroplasty surgery. A review was made on 50 patients on preoperative antiplatelet agents and 83 patients without preoperative antiplatelet agents. Patients in both groups were treated with cemented hip hemiarthroplasty. A statistical comparison was performed using epidemiological data, comorbidities, mental state, complications and mortality. There was no lost to follow-up. The one-year mortality was 20.3%. In patients without preoperative antiplatelet agents it was 14.4% and in patients with preoperative antiplatelet agents was 30%. Age, ASA grade, number of comorbidities and antiplatelet agent therapy were predictors of one-year mortality. The one-year mortality of patients on clopidogrel was 46.1%, versus 24.3% in patients on acetylsalicylic acid. Patients with preoperative antiplatelet therapy were older and had greater number of comorbidities, ASA grade, delayed surgery, and a longer length of stay than patients without antiplatelet therapy. The one-year mortality was higher in patients with preoperative antiplatelet therapy. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

  17. Revision shoulder arthroplasty from resurfacing to non-cemented short-stem reverse prosthesis.

    PubMed

    Natera, L; Bruguera, J; Atoun, E; Levy, O

    2016-01-01

    To assess the surgical parameters and the clinical and radiological outcomes of revisions of resurfacing shoulder arthroplasty to non-cemented short-stem reverse total shoulder arthroplasty. A total of 23 revisions from resurfacing shoulder arthroplasty to reverse total shoulder arthroplasty were performed. The mean age was 70.3±11.95 years. The patients included 82.6% (19/23) revised for cuff failure; 13.04% (3/23) cuff failure and aseptic loosening, and 4.35% (1/23) peri-prosthetic fracture. The need for humeral osteotomy or structural allograft, operation length, blood loss, blood transfusions and intraoperative fractures were recorded. Minimum follow-up 25 months. No humeral osteotomy or humeral structural allograft was required, and 2/23 (8.69%) required allograft for glenoid reconstruction. The mean operation time was 113.35±21.30minutes. Intra-operative blood loss was 374±245.09 mls. Blood transfusion was required in one case. Intra-operative fracture occurred in 1 case. The Constant score improved from 17.32 to 59.78 (age/sex adjusted, 84). Overall satisfaction improved from 1.37 to 8.04. The range of motion increased 79.57° in forward elevation; 72.88° in abduction; 38.06° in internal rotation; and 13.57° in external rotation. There was no evidence of radiolucency, subsidence, or bone resorption. Revisions of resurfacing implants to non-cemented short-stem reverse prosthesis show good clinical and radiological outcomes, with minimal intra-operative complexities. IV, case series. Copyright © 2016 SECOT. Published by Elsevier Espana. All rights reserved.

  18. Design of new generation femoral prostheses using functionally graded materials: a finite element analysis.

    PubMed

    Oshkour, A A; Abu Osman, N A; Yau, Y H; Tarlochan, F; Abas, W A B Wan

    2013-01-01

    This study aimed to develop a three-dimensional finite element model of a functionally graded femoral prosthesis. The model consisted of a femoral prosthesis created from functionally graded materials (FGMs), cement, and femur. The hip prosthesis was composed of FGMs made of titanium alloy, chrome-cobalt, and hydroxyapatite at volume fraction gradient exponents of 0, 1, and 5, respectively. The stress was measured on the femoral prosthesis, cement, and femur. Stress on the neck of the femoral prosthesis was not sensitive to the properties of the constituent material. However, stress on the stem and cement decreased proportionally as the volume fraction gradient exponent of the FGM increased. Meanwhile, stress became uniform on the cement mantle layer. In addition, stress on the femur in the proximal part increased and a high surface area of the femoral part was involved in absorbing the stress. As such, the stress-shielding area decreased. The results obtained in this study are significant in the design and longevity of new prosthetic devices because FGMs offer the potential to achieve stress distribution that more closely resembles that of the natural bone in the femur.

  19. Cytotoxic effects of glass ionomer cements on human dental pulp stem cells correlate with fluoride release.

    PubMed

    Kanjevac, Tatjana; Milovanovic, Marija; Volarevic, Vladislav; Lukic, Miodrag L; Arsenijevic, Nebojsa; Markovic, Dejan; Zdravkovic, Nebojsa; Tesic, Zivoslav; Lukic, Aleksandra

    2012-01-01

    Glass ionomer cements (GICs) are commonly used as restorative materials. Responses to GICs differ among cell types and it is therefore of importance to thoroughly investigate the influence of these restorative materials on pulp stem cells that are potential source for dental tissue regeneration. Eight biomaterials were tested: Fuji I, Fuji II, Fuji VIII, Fuji IX, Fuji Plus, Fuji Triage, Vitrebond and Composit. We compared their cytotoxic activity on human dental pulp stem cells (DPSC) and correlated this activity with the content of Fluoride, Aluminium and Strontium ions in their eluates. Elution samples of biomaterials were prepared in sterile tissue culture medium and the medium was tested for toxicity by an assay of cell survival/proliferation (MTT test) and apoptosis (Annexin V FITC Detection Kit). Concentrations of Fluoride, Aluminium and Strontium ions were tested by appropriate methods in the same eluates. Cell survival ranged between 79.62% (Fuji Triage) to 1.5% (Fuji Plus) and most dead DPSCs were in the stage of late apoptosis. Fluoride release correlated with cytotoxicity of GICs, while Aluminium and Strontium ions, present in significant amount in eluates of tested GICs did not. Fuji Plus, Vitrebond and Fuji VIII, which released fluoride in higher quantities than other GICs, were highly toxic to human DPSCs. Opposite, low levels of released fluoride correlated to low cytotoxic effect of Composit, Fuji I and Fuji Triage.

  20. In vivo testing of porous Ti-25Nb alloy serving as a femoral stem prosthesis in a rabbit model

    PubMed Central

    Weng, Xiaojun; Yang, Hailin; Xu, Jian; Li, Xiaosheng; Liao, Qiande; Wang, Jing

    2016-01-01

    The aim of the present study was to observe the performance of Ti-25Nb alloys with various porosities as femoral stem prostheses in a rabbit model, thus providing basic experimental evidence for the development of porous prostheses. The porous Ti-25Nb alloy prostheses were designed according to the morphology of the medullary cavity. These prostheses were placed into the femoral medullary cavities in 36 New Zealand white rabbits. Postoperative X-ray films, scanning electron microscopy (SEM) of the implant interface, energy-dispersive spectroscopy (EDS) analysis of the implant surface, pulling-out test and general observations were conducted. The specimens showed good biocompatibility; there was no obvious bone absorption in porous Ti-25Nb specimens with different porosities at different time points observed using X-ray films. Under SEM examination, calcium deposits were observed inside the pores and in the interface between bone and prostheses. The EDS analysis demonstrated that calcium deposits were present on the surface of the prostheses at the eight-week point postoperatively. The pulling-out test showed good bonding strength between bone and implant; after pulling out, the surface and inside the pores of the prostheses all presented bone mass. Porous Ti-25Nb alloy implants presents good biocompatibility as well as providing a biological fixation between the bone and implant. A porosity of 70% is more advantageous to the newborn bone ingrowth, combined with achieving a more solid bone-implant interface. PMID:27602063

  1. Preclinical Study of Cell Therapy for Osteonecrosis of the Femoral Head with Allogenic Peripheral Blood-Derived Mesenchymal Stem Cells

    PubMed Central

    Fu, Qiang; Tang, Ning-Ning; Zhang, Qian; Liu, Yi; Peng, Jia-Chen; Fang, Ning; Yu, Li-Mei; Liu, Jin-Wei

    2016-01-01

    Purpose To explore the value of transplanting peripheral blood-derived mesenchymal stem cells from allogenic rabbits (rPBMSCs) to treat osteonecrosis of the femoral head (ONFH). Materials and Methods rPBMSCs were separated/cultured from peripheral blood after granulocyte colony-stimulating factor mobilization. Afterwards, mobilized rPBMSCs from a second passage labeled with PKH26 were transplanted into rabbit ONFH models, which were established by liquid nitrogen freezing, to observe the effect of rPBMSCs on ONFH repair. Then, the mRNA expressions of BMP-2 and PPAR-γ in the femoral head were assessed by RT-PCR. Results After mobilization, the cultured rPBMSCs expressed mesenchymal markers of CD90, CD44, CD29, and CD105, but failed to express CD45, CD14, and CD34. The colony forming efficiency of mobilized rPBMSCs ranged from 2.8 to 10.8 per million peripheral mononuclear cells. After local transplantation, survival of the engrafted cells reached at least 8 weeks. Therein, BMP-2 was up-regulated, while PPAR-γ mRNA was down-regulated. Additionally, bone density and bone trabeculae tended to increase gradually. Conclusion We confirmed that local transplantation of rPBMSCs benefits ONFH treatment and that the beneficial effects are related to the up-regulation of BMP-2 expression and the down-regulation of PPAR-γ expression. PMID:27189298

  2. Exosomes Secreted from Human-Induced Pluripotent Stem Cell-Derived Mesenchymal Stem Cells Prevent Osteonecrosis of the Femoral Head by Promoting Angiogenesis.

    PubMed

    Liu, Xiaolin; Li, Qing; Niu, Xin; Hu, Bin; Chen, Shengbao; Song, Wenqi; Ding, Jian; Zhang, Changqing; Wang, Yang

    2017-01-01

    Background: Local ischemia is the main pathological performance in osteonecrosis of the femoral head (ONFH). There is currently no effective therapy to promote angiogenesis in the femoral head. Recent studies revealed that exosomes secreted by induced pluripotent stem cell-derived mesenchymal stem cells (iPS-MSC-Exos) have great therapeutic potential in ischemic tissues, but whether they could promote angiogenesis in ONFH has not been reported, and little is known regarding the underlying mechanism. Methods: iPS-MSC-Exos were intravenously injected to a steroid-induced rat osteonecrosis model. Samples of the femoral head were obtained 3 weeks after all the injections. The effects were assessed by measuring local angiogenesis and bone loss through histological and immunohistochemical (IHC) staining, micro-CT and three-dimensional microangiography. The effects of exosomes on endothelial cells were studied through evaluations of proliferation, migration and tube-forming analyses. The expression levels of angiogenic related PI3K/Akt signaling pathway of endothelial cells were evaluated following stimulation of iPS-MSC-Exos. The promoting effects of exosomes were re-evaluated following blockade of PI3K/Akt. Results: The in vivo study revealed that administration of iPS-MSC-Exos significantly prevented bone loss, and increased microvessel density in the femoral head compared with control group. We found that iPS-MSC-Exos significantly enhanced the proliferation, migration and tube-forming capacities of endothelial cells in vitro. iPS-MSC-Exos could activate PI3K/Akt signaling pathway in endothelial cells. Moreover, the promoting effects of iPS-MSC-Exos were abolished after blockade of PI3K/Akt on endothelial cells. Conclusions: Our findings suggest that transplantation of iPS-MSC-Exos exerts a preventative effect on ONFH by promoting local angiogenesis and preventing bone loss. The promoting effect might be attributed to activation of the PI3K/Akt signaling pathway on

  3. Exosomes Secreted from Human-Induced Pluripotent Stem Cell-Derived Mesenchymal Stem Cells Prevent Osteonecrosis of the Femoral Head by Promoting Angiogenesis

    PubMed Central

    Liu, Xiaolin; Li, Qing; Niu, Xin; Hu, Bin; Chen, Shengbao; Song, Wenqi; Ding, Jian; Zhang, Changqing; Wang, Yang

    2017-01-01

    Background: Local ischemia is the main pathological performance in osteonecrosis of the femoral head (ONFH). There is currently no effective therapy to promote angiogenesis in the femoral head. Recent studies revealed that exosomes secreted by induced pluripotent stem cell-derived mesenchymal stem cells (iPS-MSC-Exos) have great therapeutic potential in ischemic tissues, but whether they could promote angiogenesis in ONFH has not been reported, and little is known regarding the underlying mechanism. Methods: iPS-MSC-Exos were intravenously injected to a steroid-induced rat osteonecrosis model. Samples of the femoral head were obtained 3 weeks after all the injections. The effects were assessed by measuring local angiogenesis and bone loss through histological and immunohistochemical (IHC) staining, micro-CT and three-dimensional microangiography. The effects of exosomes on endothelial cells were studied through evaluations of proliferation, migration and tube-forming analyses. The expression levels of angiogenic related PI3K/Akt signaling pathway of endothelial cells were evaluated following stimulation of iPS-MSC-Exos. The promoting effects of exosomes were re-evaluated following blockade of PI3K/Akt. Results: The in vivo study revealed that administration of iPS-MSC-Exos significantly prevented bone loss, and increased microvessel density in the femoral head compared with control group. We found that iPS-MSC-Exos significantly enhanced the proliferation, migration and tube-forming capacities of endothelial cells in vitro. iPS-MSC-Exos could activate PI3K/Akt signaling pathway in endothelial cells. Moreover, the promoting effects of iPS-MSC-Exos were abolished after blockade of PI3K/Akt on endothelial cells. Conclusions: Our findings suggest that transplantation of iPS-MSC-Exos exerts a preventative effect on ONFH by promoting local angiogenesis and preventing bone loss. The promoting effect might be attributed to activation of the PI3K/Akt signaling pathway on

  4. Intergranular corrosion-fatigue failure of cobalt-alloy femoral stems. A failure analysis of two implants.

    PubMed

    Gilbert, J L; Buckley, C A; Jacobs, J J; Bertin, K C; Zernich, M R

    1994-01-01

    Two modular hip implants with a cobalt-alloy head and a cobalt-alloy stem were retrieved after a fracture had occurred in the neck region of the femoral component, eighty-five and seventy months after implantation. Both implants failed less than one millimeter distal to the taper junction between the head and the stem (outside of the taper). The fracture surfaces of the implant were investigated with the use of scanning electron microscopy, to determine the nature of the failure process. The fractures occurred at the grain boundaries of the microstructure and appeared to be the result of three factors: porosity at the grain boundaries; intergranular corrosive attack, initiated both at the head-neck taper and at the free surface; and cyclic fatigue-loading of the stem. The corrosive attack of the free surface was initiated, in part, by the egression of surface grains and by the ingression of fluid into the intergranular regions. Sectioned surfaces showed extensive intergranular corrosive attack in the prosthetic neck localized in the region of the head-neck taper junction and penetrating deeply into the microstructure.

  5. Robot-assisted primary cementless total hip arthroplasty with a short femoral stem: a prospective randomized short-term outcome study.

    PubMed

    Lim, Seung-Jae; Ko, Kyung-Rae; Park, Chan-Woo; Moon, Young-Wan; Park, Youn-Soo

    2015-01-01

    Recently, two topical issues in total hip arthroplasty (THA) have been robot-assisted surgery and use of a short stem. The purpose of this study was to evaluate the effects of robotic milling on the accuracy of short femoral stem positioning and on the short-term clinical outcome in THA using a prospective, randomized design. We randomized 54 patients into two groups, either robotic milling group or manual rasping group. The patients were assessed clinically and radiographically at 8 weeks, 5 months, 12 months, and 24 months. Robotic milling group had a significantly longer operation time, requiring on average 8.9 min for registration and 11.2 min for milling. On the other hand, robotic milling group showed superior results in terms of stem alignment and leg length equality. Two intraoperative femoral fractures occurred only in manual rasping group. Harris hip scores and WOMAC scores at 24 months postoperatively were similar in both groups. No complications including stem loosening, infection, nerve palsy, or dislocation were encountered in either group during the follow-up period. The present study suggested that robot-assisted short stem THA could increase the accuracy of stem alignment, improve leg length equality, and help reduce the risk of intraoperative femoral fracture as compared with manual rasping. However, the clinical outcome scores did not differ between the two groups at the time of short-term follow-up. Long-term follow-up is needed to determine whether there will be a long-term clinical relevance of robot-assisted implantation of short femoral stems in THA.

  6. Results of single stage exchange arthroplasty with retention of well fixed cement-less femoral component in management of infected total hip arthroplasty

    PubMed Central

    Rahman, Wael A; Kazi, Hussain A; Gollish, Jeffery D

    2017-01-01

    AIM To investigate success of one stage exchange with retention of fixed acetabular cup. METHODS Fifteen patients treated by single stage acetabular component exchange with retention of well-fixed femoral component in infected total hip arthroplasty (THA) were retrospectively reviewed. Inclusion criteria were patients with painful chronic infected total hip. The patient had radiologically well fixed femoral components, absence of major soft tissue or bone defect compromising, and infecting organism was not poly or virulent micro-organism. The organisms were identified preoperatively in 14 patients (93.3%), coagulase negative Staphylococcus was the infecting organism in 8 patients (53.3%). RESULTS Mean age of the patients at surgery was 58.93 (± 10.67) years. Mean follow-up was 102.8 mo (36-217 mo, SD 56.4). Fourteen patients had no recurrence of the infection; one hip (6.7%) was revised for management of infection. Statistical analysis using Kaplan Meier curve showed 93.3% survival rate. One failure in our series; the infection recurred after 14 mo, the patient was treated successfully with surgical intervention by irrigation, and debridement and liner exchange. Two complications: The first patient had recurrent hip dislocation 12 years following the definitive procedure, which was managed by revision THA with abductor reconstruction and constrained acetabular liner; the second complication was aseptic loosening of the acetabular component 2 years following the definitive procedure. CONCLUSION Successful in management of infected THA when following criteria are met; well-fixed stem, no draining sinuses, non-immune compromised patients, and infection with sensitive organisms. PMID:28361019

  7. In vitro assessment of Function Graded (FG) artificial Hip joint stem in terms of bone/cement stresses: 3D Finite Element (FE) study

    PubMed Central

    2013-01-01

    Background Stress shielding in the cemented hip prosthesis occurs due to the mismatching in the mechanical properties of metallic stem and bone. This mismatching in properties is considered as one of the main reasons for implant loosening. Therefore, a new stem material in orthopedic surgery is still required. In the present study, 3D finite element modeling is used for evaluating the artificial hip joint stem that is made of Function Graded (FG) material in terms of joint stress distributions and stem length. Method 3D finite element models of different stems made of two types of FG materials and traditional stems made of Cobalt Chromium alloy (CoCrMo) and Titanium alloy (Ti) were developed using the ANSYS Code. The effects on the total artificial hip joint stresses (Shear stress and Von Mises stresses at bone cement, Von Mises stresses at bone and stem) due to using the proposed FG materials stems were investigated. The effects on the total artificial hip joint system stresses due to using different stem lengths were investigated. Results Using FG stem (with low stiffness at stem distal end and high stiffness at its proximal end) resulted in a significant reduction in shear stress at the bone cement/stem interface. Also, the Von Mises stresses at the bone cement and stem decrease significantly when using FG material instead of CoCrMo and Ti alloy. The stresses’ distribution along the bone cement length when using FG material was found to be more uniform along the whole bone cement compared with other stem materials. These more uniform stresses will help in the reduction of the artificial hip joint loosening rate and improve its short and long term performance. Conclusion FE results showed that using FG stem increases the resultant stresses at the femur bone (reduces stress shielding) compared to metallic stem. The results showed that the stem length has significant effects on the resultant shear and Von Mises stresses at bone, stem and bone cement for all types

  8. Radiostereometric migration measurement of an uncemented Cerafit® femoral stem: 26 patients followed for 10 years.

    PubMed

    Sesselmann, Stefan; Hong, Yotung; Schlemmer, Frank; Hussnaetter, Isabell; Mueller, Lutz A; Forst, Raimund; Tschunko, Franz

    2017-08-18

    Radiostereometric analysis (RSA) is the gold standard for evaluating micromotions of orthopaedic implants. The method is applied for identifying novel design weaknesses in endoprostheses. Current research frequently assesses relatively short time periods. Short-term RSA studies have been widely used for predicting the long-term stability of many hip prosthetic designs, but only a few studies have focused on uncemented hip implants, especially for extended periods. The purpose of this study was to analyse the migration pattern of the Cerafit® femoral stem within 10 years and to verify the predictive value of short-term RSA after 2 years for this uncemented femoral hip stem. Twenty-six patients were followed for 10 years. Ten years after implantation, a mean subsidence of 0.22 mm±0.56 mm, a mean internal rotation of 0.59°±1.67° and a mean maximum total point motion (MTPM) of 1.28 mm±0.54 mm were detected. The main migration took place in the first 6 weeks after surgery (subsidence of 0.36 mm±0.73 mm; internal rotation of 0.62°±1.49°, MTPM of 1.05 mm±0.68 mm). All the migration values measured were small. No late-onset migration was observed. This study suggests that the Cerafit® implants are stable after 10 years. Thus, RSA could be the best tool to assess long-term implant behaviour.

  9. Mesenchymal Stem Cells Systemically Injected into Femoral Marrow of Dogs Home to Mandibular Defects to Enhance New Bone Formation

    PubMed Central

    Liu, Xian; Liao, Xuejuan; Luo, En; Chen, Wenchuan; Xu, Hockin H.K.

    2014-01-01

    Musculoskeletal diseases cost the U.S. $849 billion annually. To date, there has been no proof that remote long bone mesenchymal stem cells (BMSC) can home to craniofacial defects for bone regeneration. There has been no report that systemic BMSC injection can increase new bone formation in large animals. The objectives of this study were to use a sex-mismatched canine model for systemic BMSC injection and homing to mandibular defects and to investigate appendicular BMSC migration to craniofacial defects to increase new bone formation. Male beagle dog BMSC were injected into the femoral marrow cavity of female dogs upon which mandibular defects were created. The dogs were sacrificed at 6 weeks. Cells with Y chromosome markers were detected in defects of female dogs with systemic male BMSC injection, indicating the homing of the transplanted BMSC from femoral marrow to the mandibular defect. New bone formation in dogs with systemic BMSC injection was 20–40% higher than control without BMSC injection (p<0.05). Mineralized new bone percentage was increased by 20–40% due to systemic BMSC injection (p<0.05). In conclusion, this study proved that (1) allogeneic BMSC injected into long bone marrow are capable of homing to both appendicular and craniofacial bone in large animals and (2) systemically injected BMSC can significantly increase new bone formation in dog's mandibular defects. These results may help advance the understanding of stem cell homing and present a therapy to enhance bone repair, which may have a wide applicability to the regenerative medicine field. PMID:24125551

  10. Stair climbing is more detrimental to the cement in hip replacement than walking.

    PubMed

    Stolk, Jan; Verdonschot, Nico; Huiskes, Rik

    2002-12-01

    Stair climbing may be detrimental to cemented total hip arthroplasties, because it subjects the reconstruction to high torsional loads. The current study investigated how stair climbing contributes to damage accumulation in the cement around a femoral stem compared with walking, taking into account the different frequencies of these activities during patient functioning. In finite element analyses, the damage accumulation process in the cement mantle around a Lubinus SPII stem was simulated for three different loading histories: (1) isolated walking, representative for patients who climb no stairs; (2) isolated stair climbing; (3) alternating walking and stair climbing in a ratio of nine to one cycles, representative for patients who climb many stairs. Relative to isolated walking, isolated stair climbing increased the amount of cement damage by a factor of 6. Inclusion of 10% stair climbing cycles in the loading history increased the amount of damage by 47% relative to isolated walking. Stair climbing produced damage along the entire stem, whereas isolated walking produced damage proximomedially and around the tip only. This study confirmed that stair climbing is more risky for failure of cemented femoral stems than walking. A few stair climbing cycles during daily patient functioning increases the amount of cement damage dramatically.

  11. Effects of Tricalcium Silicate Cements on Osteogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells In Vitro

    PubMed Central

    Eid, Ashraf A.; Hussein, Khalid A.; Niu, Li-na; Li, Guo-hua; Watanabe, Ikuya; Al-Shabrawey, Mohamed; Pashley, David H.; Tay, Franklin R.

    2014-01-01

    Tricalcium silicate cements have been successfully employed in the biomedical field as bioactive bone and dentin substitutes, with widely acclaimed osteoactive properties. This research analyzed the effects of different tricalcium silicate cement formulations on the temporal osteoactivity profile of human bone marrow-derived mesenchymal stem cells (hMW-MSCs). These cells were exposed to 4 commercially-available tricalcium silicate cement formulations in osteogenic differentiation medium. After 1, 3, 7 and 10 days, quantitative real time-polymerase chain reaction and Western blotting were performed to detect the expression of target osteogenic markers ALP, RUNX2, OSX, OPN, MSX2, and OCN. After 3, 7, 14 and 21 days, alkaline phosphatase assay was performed to detect changes in intracellular enzyme level. Alizarin Red S assay was performed after 28 days to detect extracellular matrix mineralization. In the presence of tricalcium silicate cements, target osteogenic markers were downregulated at the mRNA and protein levels at all time-points. Intracellular alkaline phosphatase enzyme levels and extracellular mineralization of the experimental groups were not significantly different from the untreated control. Quantitative polymerase chain reaction results showed increases in downregulation of RUNX2, OSX, MSX2 and OCN with increase in time of exposure to the tricalcium silicate cements, while ALP showed peak downregulation at day 7. For Western blotting, OSX, OPN, MSX2 and OCN showed increased downregulation with increased exposure time to the tested cements. Alkaline phosphatase enzyme levels generally declined after day 7. Based on these results, it is concluded that tricalcium silicate cements do not induce osteogenic differentiation of hBM-MSCs in vitro. PMID:24726977

  12. Effects of tricalcium silicate cements on osteogenic differentiation of human bone marrow-derived mesenchymal stem cells in vitro.

    PubMed

    Eid, Ashraf A; Hussein, Khaled A; Niu, Li-na; Li, Guo-hua; Watanabe, Ikuya; Al-Shabrawey, Mohamed; Pashley, David H; Tay, Franklin R

    2014-07-01

    Tricalcium silicate cements have been successfully employed in the biomedical field as bioactive bone and dentin substitutes, with widely acclaimed osteoactive properties. This research analyzed the effects of different tricalcium silicate cement formulations on the temporal osteoactivity profile of human bone marrow-derived mesenchymal stem cells (hMW-MSCs). These cells were exposed to four commercially available tricalcium silicate cement formulations in osteogenic differentiation medium. After 1, 3, 7 and 10 days, quantitative real-time polymerase chain reaction and Western blotting were performed to detect expression of the target osteogenic markers ALP, RUNX2, OSX, OPN, MSX2 and OCN. After 3, 7, 14 and 21 days, alkaline phosphatase assay was performed to detect changes in intracellular enzyme level. An Alizarin Red S assay was performed after 28 days to detect extracellular matrix mineralization. In the presence of tricalcium silicate cements, target osteogenic markers were downregulated at the mRNA and protein levels at all time points. Intracellular alkaline phosphatase enzyme levels and extracellular mineralization of the experimental groups were not significantly different from the untreated control. Quantitative polymerase chain reaction results showed increases in downregulation of RUNX2, OSX, MSX2 and OCN with increasing time of exposure to the tricalcium silicate cements, while ALP showed peak downregulation at day 7. For Western blotting, OSX, OPN, MSX2 and OCN showed increased downregulation with increased exposure time to the tested cements. Alkaline phosphatase enzyme levels generally declined after day 7. Based on these results, it is concluded that tricalcium silicate cements do not induce osteogenic differentiation of hBM-MSCs in vitro. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  13. Curved-stem Hip Resurfacing

    PubMed Central

    2008-01-01

    Hip resurfacing is an attractive concept because it preserves rather than removes the femoral head and neck. Most early designs had high failure rates, but one unique design had a femoral stem. Because that particular device appeared to have better implant survival, this study assessed the clinical outcome and long-term survivorship of a hip resurfacing prosthesis. Four hundred forty-five patients (561 hips) were retrospectively reviewed after a minimum of 20 years’ followup or until death; 23 additional patients were lost to followup. Patients received a metal femoral prosthesis with a small curved stem. Three types of acetabular reconstructions were used: (1) cemented polyurethane; (2) metal-on-metal; and (3) polyethylene secured with cement or used as the liner of a two-piece porous-coated implant. Long-term results were favorable with the metal-on-metal combination only. The mean overall Harris hip score was 92 at 2 years of followup. None of the 121 patients (133 hips) who received metal-on-metal articulation experienced failure. The failure rate with polyurethane was 100%, and the failure rate with cemented polyethylene was 41%. Hip resurfacing with a curved-stem femoral component had a durable clinical outcome when a metal-on-metal articulation was used. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18338217

  14. Dimethyloxaloylglycine increases bone repair capacity of adipose-derived stem cells in the treatment of osteonecrosis of the femoral head

    PubMed Central

    Zhu, Zhen-Hong; Song, Wen-Qi; Zhang, Chang-Qing; Yin, Ji-Min

    2016-01-01

    Mesenchymal stem cells have been widely studied to promote local bone regeneration of osteonecrosis of the femoral head (ONFH). Previous studies observed that dimethyloxaloylglycine (DMOG) enhanced the angiogenic and osteogenic activity of mesenchymal stem cells by activating the expression of hypoxia inducible factor-1α (HIF-1α), thereby improving the bone repair capacity of mesenchymal stem cells. In the present study, it was investigated whether DMOG could increase the bone repair capacity of adipose-derived stem cells (ASCs) in the treatment of ONFH. Western blot analysis was performed to detect HIF-1α protein expression in ASCs treated with different concentrations of DMOG. The results showed DMOG enhanced HIF-1α expression in ASCs in a dose-dependent manner at least for 7 days. Furthermore, DMOG-treated ASCs were transplanted into the necrotic area of a rabbit model of ONFH to treat the disease. Four weeks later, micro-computed tomography (CT) quantitative analysis showed that 58.8±7.4% of the necrotic area was regenerated in the DMOG-treated ASCs transplantation group, 45.5±3.4% in normal ASCs transplantation group, 25.2±2.8% in only core decompression group and 10.6±2.6% in the untreated group. Histological analysis showed that transplantation of DMOG-treated ASCs clearly improved the bone regeneration of the necrotic area compared with the other three groups. Micro-CT and immunohistochemical analysis demonstrated the revasculation of the necrotic area were also increased significantly in the DMOG-treated ASC group compared with the control groups. Thus, it is hypothesized that DMOG could increase the bone repair capacity of ASCs through enhancing HIF-1α expression in the treatment of ONFH. PMID:27882083

  15. Restoring the femoral offset prevent early migration of the stem in total hip arthroplasty: an EBRA-FCA study.

    PubMed

    Vicenti, G; Solarino, G; Spinarelli, A; Carrozzo, M; Picca, G; Maddalena, R; Rifino, F; Moretti, B

    2016-01-01

    The use of modular stems is still debated and controversial. Some authors have highlighted a number of disadvantages of modular prostheses including high costs, the tendency to fracture, the fretting and corrosion and the increased production of debris. Other authors have emphasized several advantages to adapt the prosthesis to the morphometric differences of patients, to allow better accuracy in restoring the anatomy and biomechanics of hip joint. The advantages of the modular devices appear to be more evident in patients with developmental dysplasia of the hip (DDH). In our study we compared 96 patients, operated for arthritis of the hip with 55 modular neck prostheses (PROFEMUR®, Wright® Arlington, Tennesse, USA) and 41 standard femoral stems (SYMAX®, Striker® Kalamazoo, Michigan, USA). The precision of restoring the natural offset during surgery was correlated with the clinical outcome and the radiological early migration of each stem measured using the computer-assisted EBRA-FCA method. The average preoperative HHS (Harris Hip Score) was 44 (23-66); the postoperative 86.56 in the 55 patients operated with modular prostheses and 81.70 in the 41 patients with monoblock stem. The worst HH Scores were seen in patients in whom the offset was not restored properly. On the contrary, the best scores have been reached in patients in which that value is closer to the “target” value (offset value of the contralateral hip). Restoring the proper offset seems to determine an appropriate tension of the abductor muscles of the hip and implies a better functioning of the joint and a better primary stability of the implant, with less early migration. This has to be a primary objective of THA surgery.

  16. A Review of Periprosthetic Femoral Fractures Associated With Total Hip Arthroplasty

    PubMed Central

    Marsland, Daniel; Mears, Simon C.

    2012-01-01

    Periprosthetic fractures of the femur in association with total hip arthroplasty are increasingly common and often difficult to treat. Patients with periprosthetic fractures are typically elderly and frail and have osteoporosis. No clear consensus exists regarding the optimal management strategy because there is limited high-quality research. The Vancouver classification facilitates treatment decisions. In the presence of a stable prosthesis (type-B1 and -C fractures), most authors recommend surgical stabilization of the fracture with plates, strut grafts, or a combination thereof. In up to 20% of apparent Vancouver type-B1 fractures, the femoral stem is loose, which may explain the high failure rates associated with open reduction and internal fixation. Some authors recommend routine opening and dislocation of the hip to perform an intraoperative stem stability test to rule out a loose component. Advances in plating techniques and technology are improving the outcomes for these fractures. For fractures around a loose femoral prosthesis (types B2 and 3), revision using an extensively porous-coated uncemented long stem, with or without additional fracture fixation, appears to offer the most reliable outcome. Cement-in-cement revision using a long-stem prosthesis is feasible in elderly patients with a well-fixed cement mantle. It is essential to treat the osteoporosis to help fracture healing and to prevent further fractures. We provide an overview of the causes, classification, and management of periprosthetic femoral fractures around a total hip arthroplasty based on the current best available evidence. PMID:23569704

  17. Fatigue Debonding of the Roughened Stem–Cement Interface: Effects of Surface Roughness and Stem Heating Conditions

    PubMed Central

    Damron, Leatha A.; Kim, Do-Gyoon; Mann, Kenneth A.

    2007-01-01

    The aim of this study was to determine the effects of cyclic loading on the debond process of a roughened stem– cement interface used in total hip arthroplasty. The specific goals were to assess the effects of two surgeon-controlled variables (stem heating and degree of stem surface roughness) and to determine if an independent finite element-based fracture mechanics model could be used to predict the debond response. A clamped cantilever beam geometry was used to determine the fatigue debond response of the stem– cement interface and was created using an experimental mold that simulated in vivo cementing conditions. A second experiment was performed using a torsion-loading model representative of the stem– cement–bone composite. For both experiments, two stem heating (room temperature and 50°C) and surface roughness conditions (grit blasted: Ra = 2.3 and 5.1 μm) were used. Finally, a finite element model of the torsion experiment with provision for crack growth was developed and compared with the experimental results. Results from both experiments revealed that neither stem preheating nor use of a stem with a greater surface roughness had a marked effect on the fatigue debond response. There was substantial variability in the debond response for all cases; this may be due to microscopic gaps at the interface for all interface conditions. The debond rate from the finite element simulation (10−7.31 m/cycle) had a magnitude similar to the experimental torsion model (10− (6.77 ± 1.25) m/cycle). This suggests that within the context of the experimental conditions studied here that the debond response could be assessed using a linear elastic fracture mechanics-type approach. PMID:16292769

  18. Efficacy of umbilical cord-derived mesenchymal stem cell-based therapy for osteonecrosis of the femoral head: A three-year follow-up study

    PubMed Central

    Chen, Chun; Qu, Zhiguo; Yin, Xiaoguang; Shang, Chunyu; Ao, Qiang; Gu, Yongquan; Liu, Ying

    2016-01-01

    This is a retrospective analysis of the clinical effects of transplant of mesenchymal stem cells (MSCs) derived from human umbilical cord-derived MSCs (hUC-MSCs) for the treatment of osteonecrosis of the femoral head (ONFH). The biological characteristics of hUC-MSCs were assessed using flow cytometry. Nine eligible patients were enrolled in the study as they adhered to the Association Research Circulation Osseous (ARCO) classification of stage II–IIIa, and hUC-MSCs were grafted by intra-arterial infusion. Organize effective perfusion was assessed using the oxygen delivery index (ODI). The results showed that the ODI was increased at three days post-operation. The MRI results revealed that at 12 and 24 months after treatment, the necrotic volume of the femoral heads was significantly reduced. No obvious abnormalities were observed. Taken together, these data indicate that intra-arterially infused hUC-MSCs migrate into the necrotic field of femoral heads and differentiate into osteoblasts, thus improving the necrosis of femoral heads. This finding suggested that intra-arterial infusion of hUC-MSCs MSCs is a feasible and relatively safe method for the treatment of femoral head necrosis. PMID:27634376

  19. [Three successive fractures of different hip femoral stems on the same patient].

    PubMed

    Gómez-Robledo, J

    2016-01-01

    The clinical case of an 80-year-old female who suffered three fractures in uncemented stems implanted in her right hip in a period of three years is presented. A fracture occurred in the prosthetic neck and the other two at the juncture of the conical and cylindrical stem portion, coinciding with the metaphyseal-diaphyseal junction of the femur. The main causes of the failure were an increasing concentration of forces at the level of the implant as a consequence of the increased length of the neck and lateralization of the femur (offset). Other causes that have contributed to this prosthetic failure are analyzed.

  20. Geometric analysis and clinical outcome of two cemented stems for primary total hip replacement with and without modular necks.

    PubMed

    Haversath, Marcel; Wendelborn, Christine; Jäger, Marcus; Schmidt, Boris; Kowalczyk, Wojciech; Landgraeber, Stefan

    2017-09-15

    Restoration of the physiological biomechanical principles of the hip is crucial in total hip replacement. The aim of this study was to compare an arthroplasty system with different offset options (a: Exeter(®)) with a dual-modular stem (b: Profemur Xm(®)). A local and an inertial coordinate system were used to assist the description of the components' assembly in the prosthesis. A resection line of the femoral head in standard position was added to the arthroplasties and geometric parameters were measured. The outcomes of 93 patients were clinically evaluated (a: n = 50, b: n = 43). Preoperative planning was compared to postoperative radiographs (femoral offset, leg-length), and clinical scores (HHS, WOMAC, total range of motion) were assessed preoperatively, and then 1 and 2 years after surgery. The Exeter(®) offers an offset range from 32.1 to 56.9 mm and the Profemur Xm(®) a range from 29.3 to 55.3 mm. The leg-length variability of the Profemur Xm(®) has a range of 25.9 mm, the Exeter(®) a range of 13.7 mm. The Profemur Xm(®) offers more possible combinations of offset and leg-length reconstruction. The neck-stem angles of the Exeter(®) range from 125.2° to 126.3°, of the Profemur Xm(®) from 127.2° to 142.6°. There was no statistically significant difference in clinical outcome and radiological parameters. We conclude that both stems offer a wide range of options for anatomical reconstruction of the hip resulting in similarly good clinical results. The Profemur Xm(®) stem has advantages for the reconstruction of hips that deviate from standard anatomy but has the drawback of additional corrosive wear at the stem/neck interface.

  1. Collagen-Calcium Phosphate Cement Scaffolds Seeded with Umbilical Cord Stem Cells for Bone Tissue Engineering

    PubMed Central

    Thein-Han, WahWah

    2011-01-01

    Human umbilical cord mesenchymal stem cells (hUCMSCs) avoid the invasive procedure required to harvest bone marrow MSCs. The addition of collagen fibers into self-setting calcium phosphate cement (CPC) may increase the scaffold strength, and enhance cell attachment and differentiation. The objectives of this study were to develop a novel class of collagen-CPC composite scaffolds, and to investigate hUCMSC attachment, proliferation, and osteogenic differentiation on collagen-CPC scaffolds for the first time. Collagen fibers in CPC improved the load-bearing capability. Flow cytometry showed that the hUCMSCs expressed cell surface markers characteristic of MSCs, and were negative for hematopoietic and endothelial cell markers. hUCMSCs proliferated rapidly in all CPC composite scaffolds, with cell number increasing by sevenfold in 8 days. Cellular function was enhanced with collagen fibers in CPC scaffolds. Cell density increased from (645±60) cells/mm2 on CPC with 0% collagen, to (1056±65) cells/mm2 on CPC with 8% collagen (p<0.05). The actin stress fibers inside the hUCMSCs were stained, and the fluorescence intensity was doubled when the collagen in CPC was increased by 0% to 8%. RT-PCR showed that hUCMSCs on CPC with collagen had higher osteogenic expression than those on CPC without collagen. Alizarin Red S staining revealed a great increase in mineralization by hUCMSCs on CPC with collagen than that without collagen. In conclusion, hUCMSCs showed excellent proliferation, differentiation, and synthesis of bone minerals in collagen-CPC composite scaffolds for the first time. The novel hUCMSC-seeded collagen-CPC construct with superior cell function and load-bearing capability is promising to enhance bone regeneration in a wide range of orthopedic and craniofacial applications. PMID:21851269

  2. Collagen-calcium phosphate cement scaffolds seeded with umbilical cord stem cells for bone tissue engineering.

    PubMed

    Thein-Han, WahWah; Xu, Hockin H K

    2011-12-01

    Human umbilical cord mesenchymal stem cells (hUCMSCs) avoid the invasive procedure required to harvest bone marrow MSCs. The addition of collagen fibers into self-setting calcium phosphate cement (CPC) may increase the scaffold strength, and enhance cell attachment and differentiation. The objectives of this study were to develop a novel class of collagen-CPC composite scaffolds, and to investigate hUCMSC attachment, proliferation, and osteogenic differentiation on collagen-CPC scaffolds for the first time. Collagen fibers in CPC improved the load-bearing capability. Flow cytometry showed that the hUCMSCs expressed cell surface markers characteristic of MSCs, and were negative for hematopoietic and endothelial cell markers. hUCMSCs proliferated rapidly in all CPC composite scaffolds, with cell number increasing by sevenfold in 8 days. Cellular function was enhanced with collagen fibers in CPC scaffolds. Cell density increased from (645±60) cells/mm(2) on CPC with 0% collagen, to (1056±65) cells/mm(2) on CPC with 8% collagen (p<0.05). The actin stress fibers inside the hUCMSCs were stained, and the fluorescence intensity was doubled when the collagen in CPC was increased by 0% to 8%. RT-PCR showed that hUCMSCs on CPC with collagen had higher osteogenic expression than those on CPC without collagen. Alizarin Red S staining revealed a great increase in mineralization by hUCMSCs on CPC with collagen than that without collagen. In conclusion, hUCMSCs showed excellent proliferation, differentiation, and synthesis of bone minerals in collagen-CPC composite scaffolds for the first time. The novel hUCMSC-seeded collagen-CPC construct with superior cell function and load-bearing capability is promising to enhance bone regeneration in a wide range of orthopedic and craniofacial applications.

  3. Strain shielding inspired re-design of proximal femoral stems for total hip arthroplasty.

    PubMed

    Cilla, Myriam; Checa, Sara; Duda, Georg N

    2017-02-08

    A large number of hip prosthesis with different designs have been developed. However, the influence of hip implant design changes on the strains induced in the bone remains unclear. The purpose of this study is to better understand the mechanics of short stem total hip arthroplasty. Specifically, it investigates whether strain shielding can be avoided by changing implant shape and/or material properties. It is hypothesized that the re-design of existing implant designs can result in further reduction of strain shielding and thus keep bone loss minimal following total hip replacement. Finite element methods were used to compare healthy and implanted models. The local mechanics strains/stresses in the intact and implanted femurs were determined under patient-specific muscle and joint contact forces. Results suggest that small changes in implant geometry and material properties have no major effect on strain shielding. Furthermore, it was found that improvement depends on a dramatic re-design of the original implant design. Whereas the benefit of this strategy of modification of the original geometry of a given short-stemmed hip consists in reduced bone remodeling, care should be taken with regard to long-term bone anchorage and implant fatigue strength. It is also shown that geometrical and material changes have a limited potential in avoiding strain shielding even in short-stemmed implants. Finally, it is suggested that an understanding of the influence of these changes on the strain distribution within the bone can guide in the process of optimizing the current stem designs toward minimal strain shielding effects. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

  4. Determining material loss from the femoral stem trunnion in hip arthroplasty using a coordinate measuring machine.

    PubMed

    Bone, Martin C; Sidaginamale, Raghavendra P; Lord, James K; Scholes, Susan C; Joyce, Thomas J; Nargol, Anthony V F; Langton, David J

    2015-01-01

    In contrast to the articulating and taper surfaces of failed total hip replacements, volumetric wear analysis of trunnions is not routinely performed. Metal wear particles from the trunnion may contribute not only to the failures of metal-on-metal total hip replacements but also to all hip replacements utilising metal trunnions. A validation study was performed with the material removed in stages from the trunnions of an Exeter V40 stem, a Corail stem and an Accolade stem to simulate different magnitudes of wear. The material loss from the trunnions was measured both volumetrically with a coordinate measuring machine and gravimetrically with a high-precision balance. A cohort of 28 ex vivo trunnions was also measured using the coordinate measuring machine. The maximum error between the two methods was found to be 0.13 mm(3). This result was comparable with the coordinate measuring machine method for the taper surface (0.2 mm(3)). The ex vivo trunnions had a median wear volume of 0.14mm(3) (range: 0.04-0.28 mm(3)). This is the first study to determine the accuracy of volumetric wear measurements of trunnions by comparing against gravimetric measurements. Volumetric wear analysis of trunnions may provide additional insights into failures of modular total hip prostheses and will be performed routinely at our centre. © IMechE 2015.

  5. Skeletal muscle perfusion and stem cell delivery in muscle disorders using intra-femoral artery canulation in mice.

    PubMed

    Matthias, Nadine; Hunt, Samuel D; Wu, Jianbo; Darabi, Radbod

    2015-11-15

    Muscular dystrophies are among major inherited muscle disorders characterized by progressive muscle damage and fibrosis with no definitive cure. Recently, gene or cell based therapies have been developed to restore the missing gene expression or replace the damaged tissues. In order to test the efficiency of these therapies in mice models of muscular dystrophies, the arterial route of delivery is very advantageous as it provides uniform muscle exposure to the therapeutic agents or cells. Although there are few reports of arterial delivery of the therapeutic agents or cells in mice, there is no in-depth description and evaluation of its efficacy in perfusion of downstream muscles. This study is aimed to develop a practical method for intra-femoral artery perfusion in mice and to evaluate perfusion efficiency using near-infrared-fluorescence (NIRF) imaging as well as histology following stem cell delivery. Our results provide a practical guide to perform this delicate method in mice. By using a sensitive fluorescent dye, different muscle groups of the hindlimb have been evaluated for proper perfusion. As the final step, we have validated the efficiency of arterial cell delivery into muscles using human iPS-derived myogenic cells in an immunodeficient mouse model for Duchenne muscular dystrophy (NSG-mdx(4cv)).

  6. The effect of mesenchymal stem cell sheets on structural allograft healing of critical-sized femoral defects in mice

    PubMed Central

    Long, Teng; Zhu, Zhenan; Awad, Hani A.; Schwarz, Edward M.; Hilton, Matthew J.; Dong, Yufeng

    2014-01-01

    Structural bone allografts are widely used in the clinic to treat critical sized bone defects, despite lacking the osteoinductive characteristics of live autografts. To address this, we generated revitalized structural allografts wrapped with mesenchymal stem/progenitor cell (MSC) sheets, which were produced by expanding primary syngenic bone marrow derived cells on temperature-responsive plates, as a tissue engineered periosteum. In vitro assays demonstrated maintenance of the MSC phenotype in the sheets, suggesting that short-term culturing of MSC sheets is not detrimental. To test their efficacy in vivo, allografts wrapped with MSC sheets were transplanted into 4-mm murine femoral defects and compared to allografts with direct seeding of MSCs and allografts without cells. Evaluations consisted of x-ray plain radiography, 3D microCT, histology, and biomechanical testing at 4- and 6-weeks post-surgery. Our findings demonstrate that MSC sheets induce prolonged cartilage formation at the graft-host junction and enhanced bone callus formation, as well as graft-host osteointegration. Moreover, a large periosteal callus was observed spanning the allografts with MSC sheets, which partially mimics live autograft healing. Finally, biomechanical testing showed a significant increase in the structural and functional properties of MSC sheet grafted femurs. Taken together, MSC sheets exhibit enhanced osteogenicity during critical sized bone defect repair, demonstrating the feasibility of this tissue engineering solution for massive allograft healing. PMID:24393269

  7. The effect of mesenchymal stem cell sheets on structural allograft healing of critical sized femoral defects in mice.

    PubMed

    Long, Teng; Zhu, Zhenan; Awad, Hani A; Schwarz, Edward M; Hilton, Matthew J; Dong, Yufeng

    2014-03-01

    Structural bone allografts are widely used in the clinic to treat critical sized bone defects, despite lacking the osteoinductive characteristics of live autografts. To address this, we generated revitalized structural allografts wrapped with mesenchymal stem/progenitor cell (MSC) sheets, which were produced by expanding primary syngenic bone marrow derived cells on temperature-responsive plates, as a tissue-engineered periosteum. In vitro assays demonstrated maintenance of the MSC phenotype in the sheets, suggesting that short-term culturing of MSC sheets is not detrimental. To test their efficacy in vivo, allografts wrapped with MSC sheets were transplanted into 4-mm murine femoral defects and compared to allografts with direct seeding of MSCs and allografts without cells. Evaluations consisted of X-ray plain radiography, 3D microCT, histology, and biomechanical testing at 4- and 6-weeks post-surgery. Our findings demonstrate that MSC sheets induce prolonged cartilage formation at the graft-host junction and enhanced bone callus formation, as well as graft-host osteointegration. Moreover, a large periosteal callus was observed spanning the allografts with MSC sheets, which partially mimics live autograft healing. Finally, biomechanical testing showed a significant increase in the structural and functional properties of MSC sheet grafted femurs. Taken together, MSC sheets exhibit enhanced osteogenicity during critical sized bone defect repair, demonstrating the feasibility of this tissue engineering solution for massive allograft healing.

  8. The Healing Effect of Adipose-Derived Mesenchymal Stem Cells in Full-thickness Femoral Articular Cartilage Defects of Rabbit

    PubMed Central

    Mehrabani, D.; Babazadeh, M.; Tanideh, N.; Zare, S.; Hoseinzadeh, S.; Torabinejad, S.; Koohi-Hosseinabadi, O.

    2015-01-01

    Background: Articular cartilage defect can lead to degradation of subchondral bone and osteoarthritis (OA). Objective: To determine the healing effect of transplantation of adipose-derived mesenchymal stem cells (Ad-MSCs) in full-thickness femoral articular cartilage defects in rabbit. Methods: 12 rabbits were equally divided into cell-treated and control groups. In cell-treated group, 2×106 cells of third passage suspended in 1 mL of DMEM was injected into articular defect. The control group just received 1 mL of DMEM. Dulbecco’s modified Eagles medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 1% penicillin and streptomycin and 2 mM L-glutamine were used for cell culture. To induce cartilage defect, 4 mm articular cartilage full-thickness defect was created in the knee. For histological evaluation in each group (H&E, safranin-O and toluidine blue), 3 rabbits were sacrificed 4 weeks and 3 animals, 8 weeks after cell transplantation. Results: In cell therapy group post-transplantation, no abnormal gross findings were noticed. Neo-formed tissues in cell-treated groups were translucent with a smooth and intact surface and less irregularity. In cell-treated group after 8 weeks post-transplantation, the overall healing score of experimental knees were superior when compared to other groups. Conclusion: We showed that Ad-MSCs, as an available and non-invasive produced source of cells, could be safely administered in knee osteochondral defects. PMID:26576262

  9. The effect of stem material and surface treatment on the torsional stability at the metal-cement interface of upper limb joint replacement systems.

    PubMed

    Hosein, Yara K; King, Graham J W; Dunning, Cynthia E

    2014-08-01

    Stem surface treatment and material are two design factors that may affect the onset of implant loosening. For upper limb applications, no known in vitro studies have addressed the role of these two factors on cemented implant stability. Therefore, the purpose of this study was to compare the torsional stability of cemented titanium and cobalt chrome stems with varying surface treatments in vitro. Thirty implant stems of circular cross-section (Ø = 8mm) were machined from cobalt chrome (n = 15) and titanium (n = 15). For each type, stems were subdivided into three groups for application of clinically relevant surface treatments: smooth, sintered beads, or plasma spray. Stems were potted in bone cement, allowed 24 h to cure, and placed in a materials testing machine. Stems were tested under cyclic torsion (1-30 Nm), using a staircase loading protocol. Failure was defined as either the first rapid increase in stem rotation without resistance, or attaining a maximum torque of 30 Nm. Implant stems with non-smooth surfaces offered greater resistance to torsion (p < 0.05), with the plasma spray treatment outlasting the beaded and smooth stems (p < 0.05). Titanium offered superior interface strength (p < 0.05) but reduced resistance to motion (p < 0.05) when compared to cobalt chrome. Therefore, these design features should be considered during upper limb implant design.

  10. Effect of a collar on subsidence and local micromotion of cementless femoral stems: in vitro comparative study based on micro-computerised tomography.

    PubMed

    Malfroy Camine, Valérie; Rüdiger, Hannes A; Pioletti, Dominique P; Terrier, Alexandre

    2017-06-07

    The aim of this study is to quantitatively compare the difference in primary stability between collarless and collared versions of the same femoral stem. Specifically, we tested differences in subsidence and micromotion. Collarless and collared versions of the same cementless femoral stem were implanted in two groups of six fresh-frozen cadaveric femurs. Each implanted femur was then subsequently tested for axial compressive and torsional loadings. A micro-CT based technique was applied to quantify implant subsidence and compute the map of local micromotion around the femoral stems. Micromotion of collarless and collared stems was compared in each Gruen zone. Subsidence was higher but not significantly (p = 0.352) with collarless (41.0 ± 29.9 μm) than with collared stems (37.0 ± 44.6 μm). In compression, micromotion was lower (p = 0.257) with collarless (19.5 ± 5 μm) than with collared stems (43.3 ± 33.1 μm). In torsion, micromotion was also lower (p = 0.476) with collarless (96.9 ± 59.8 μm) than collared stems (118.7 ± 45.0 μm). Micromotion was only significantly lower (p = 0.001) in Gruen zone 1 and for compression with collarless (7.0 ± 0.6 μm) than with collared stems (22.6 ± 25.5 μm). Primary stability was achieved for both stem designs, with a mean micromotion below the osseointegration threshold. Under loading conditions similar to those observed in normal daily activity and with good press-fit, the collar had no influence on subsidence or micromotion. Further studies are required to test the potential advantage of collar with higher loads, undersized stems, or osteoporotic femurs.

  11. Vascular endothelial growth factor/bone morphogenetic protein-2 bone marrow combined modification of the mesenchymal stem cells to repair the avascular necrosis of the femoral head

    PubMed Central

    Ma, Xiao-Wei; Cui, Da-Ping; Zhao, De-Wei

    2015-01-01

    Vascular endothelial cell growth factor (VEGF) combined with bone morphogenetic protein (BMP) was used to repair avascular necrosis of the femoral head, which can maintain the osteogenic phenotype of seed cells, and effectively secrete VEGF and BMP-2, and effectively promote blood vessel regeneration and contribute to formation and revascularization of tissue engineered bone tissues. To observe the therapeutic effect on the treatment of avascular necrosis of the femoral head by using bone marrow mesenchymal stem cells (BMSCs) modified by VEGF-165 and BMP-2 in vitro. The models were avascular necrosis of femoral head of rabbits on right leg. There groups were single core decompression group, core decompression + BMSCs group, core decompression + VEGF-165/BMP-2 transfect BMSCs group. Necrotic bone was cleared out under arthroscope. Arthroscopic observation demonstrated that necrotic bone was cleared out in each group, and fresh blood flowed out. Histomorphology determination showed that blood vessel number and new bone area in the repair region were significantly greater at various time points following transplantation in the core decompression + VEGF-165/BMP-2 transfect BMSCs group compared with single core decompression group and core decompression + BMSCs group (P < 0.05). These suggested that VEGF-165/BMP-2 gene transfection strengthened osteogenic effects of BMSCs, elevated number and quality of new bones and accelerated the repair of osteonecrosis of the femoral head. PMID:26629044

  12. Fatigue design of a mechanically biocompatible lattice for a proof-of-concept femoral stem.

    PubMed

    Arabnejad Khanoki, Sajad; Pasini, Damiano

    2013-06-01

    A methodology is proposed to design a spatially periodic microarchitectured material for a two-dimensional femoral implant under walking gait conditions. The material is composed of a graded lattice with controlled property distribution that minimizes concurrently bone resorption and interface failure. The periodic microstructure of the material is designed for fatigue fracture caused by cyclic loadings on the hip joint as a result of walking. The bulk material of the lattice is Ti6AL4V and its microstructure is assumed free of defects. The Soderberg diagram is used for the fatigue design under multiaxial loadings. Two cell topologies, square and Kagome, are chosen to obtain optimized property gradients for a two-dimensional implant. Asymptotic homogenization (AH) theory is used to address the multiscale mechanics of the implant as well as to capture the stress and strain distribution at both the macro and the microscale. The microstress distribution found with AH is also compared with that obtained from a detailed finite element analysis. For the maximum value of the von Mises stress, we observe a deviation of 18.6% in unit cells close to the implant boundary, where the AH assumption of spatial periodicity of the fluctuating fields ceases to hold. In the second part of the paper, the metrics of bone resorption and interface shear stress are used to benchmark the graded cellular implant with existing prostheses made of fully dense titanium implant. The results show that the amount of initial postoperative bone loss for square and Kagome lattice implants decreases, respectively, by 53.8% and 58%. In addition, the maximum shear interface failure at the distal end is significantly reduced by about 79%. A set of proof-of-concepts of planar implants have been fabricated via Electron Beam Melting (EBM) to demonstrate the manufacturability of Ti6AL4V into graded lattices with alternative cell size. Optical microscopy has been used to measure the morphological parameters

  13. Adverse Local Tissue Reaction Arising from Corrosion at the Femoral Neck-Body Junction in a Dual-Taper Stem with a Cobalt-Chromium Modular Neck

    PubMed Central

    Cooper, H. John; Urban, Robert M.; Wixson, Richard L.; Meneghini, R. Michael; Jacobs, Joshua J.

    2013-01-01

    Background: Femoral stems with dual-taper modularity were introduced to allow additional options for hip-center restoration independent of femoral fixation in total hip arthroplasty. Despite the increasing availability and use of these femoral stems, concerns exist about potential complications arising from the modular neck-body junction. Methods: This was a multicenter retrospective case series of twelve hips (eleven patients) with adverse local tissue reactions secondary to corrosion at the modular neck-body junction. The cohort included eight women and three men who together had an average age of 60.1 years (range, forty-three to seventy-seven years); all hips were implanted with a titanium-alloy stem and cobalt-chromium-alloy neck. Patients presented with new-onset and increasing pain at a mean of 7.9 months (range, five to thirteen months) following total hip arthroplasty. After serum metal-ion studies and metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) revealed abnormal results, the patients underwent hip revision at a mean of 15.2 months (range, ten to twenty-three months). Tissue specimens were examined by a single histopathologist, and the retrieved implants were studied with use of light and scanning electron microscopy. Results: Serum metal levels demonstrated greater elevation of cobalt (mean, 6.0 ng/mL) than chromium (mean, 0.6 ng/mL) or titanium (mean, 3.4 ng/mL). MRI with use of MARS demonstrated adverse tissue reactions in eight of nine patients in which it was performed. All hips showed large soft-tissue masses and surrounding tissue damage with visible corrosion at the modular femoral neck-body junction. Available histology demonstrated large areas of tissue necrosis in seven of ten cases, while remaining viable capsular tissue showed a dense lymphocytic infiltrate. Microscopic analysis was consistent with fretting and crevice corrosion at the modular neck-body interface. Conclusions: Corrosion at the modular neck

  14. Adverse local tissue reaction arising from corrosion at the femoral neck-body junction in a dual-taper stem with a cobalt-chromium modular neck.

    PubMed

    Cooper, H John; Urban, Robert M; Wixson, Richard L; Meneghini, R Michael; Jacobs, Joshua J

    2013-05-15

    Femoral stems with dual-taper modularity were introduced to allow additional options for hip-center restoration independent of femoral fixation in total hip arthroplasty. Despite the increasing availability and use of these femoral stems, concerns exist about potential complications arising from the modular neck-body junction. This was a multicenter retrospective case series of twelve hips (eleven patients) with adverse local tissue reactions secondary to corrosion at the modular neck-body junction. The cohort included eight women and three men who together had an average age of 60.1 years (range, forty-three to seventy-seven years); all hips were implanted with a titanium-alloy stem and cobalt-chromium-alloy neck. Patients presented with new-onset and increasing pain at a mean of 7.9 months (range, five to thirteen months) following total hip arthroplasty. After serum metal-ion studies and metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) revealed abnormal results, the patients underwent hip revision at a mean of 15.2 months (range, ten to twenty-three months). Tissue specimens were examined by a single histopathologist, and the retrieved implants were studied with use of light and scanning electron microscopy. Serum metal levels demonstrated greater elevation of cobalt (mean, 6.0 ng/mL) than chromium (mean, 0.6 ng/mL) or titanium (mean, 3.4 ng/mL). MRI with use of MARS demonstrated adverse tissue reactions in eight of nine patients in which it was performed. All hips showed large soft-tissue masses and surrounding tissue damage with visible corrosion at the modular femoral neck-body junction. Available histology demonstrated large areas of tissue necrosis in seven of ten cases, while remaining viable capsular tissue showed a dense lymphocytic infiltrate. Microscopic analysis was consistent with fretting and crevice corrosion at the modular neck-body interface. Corrosion at the modular neck-body junction in dual-tapered stems with a modular

  15. Human tooth germ stem cell response to calcium-silicate based endodontic cements

    PubMed Central

    PAMUKÇU GÜVEN, Esra; YALVAÇ, Mehmet Emir; KAYAHAN, Mehmet Baybora; SUNAY, Hakkı; ŞAHİN, Fikrettin; BAYIRLI, Gündüz

    2013-01-01

    Objective The aim of this study was to compare the cytotoxic effects of endodontic cements on human tooth germ stem cells (hTGSCs). MTA Fillapex, a mineral trioxide aggregate (MTA)-based, salicylate resin containing root canal sealer, was compared with iRoot SP, a bioceramic sealer, and AH Plus Jet, an epoxy resin-based root canal sealer. Material and Methods To evaluate cytotoxicity, all materials were packed into Teflon rings (4 mmµ3 mm) and co-cultured with hTGSCs with the aid of 24-well Transwell permeable supports, which had a pore size of 0.4 µm. Coverslips were coated with MTA Fillapex, iRoot SP and AH Plus Jet and each coverslip was placed onto the bottom of one well of a six-well plate for scanning electron microscopy (SEM) analysis. Before the cytotoxicity and SEM analysis, all samples were stored at 37ºC and at 95% humidity and 5% CO2 for 24 hours to set. The cellular viability was analyzed using MTS test (3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxy-phenyl)-2-(4-sulfo-phenyl)-2H-tetrazolium). The cytotoxic effects and SEM visualization of the tested materials were analyzed at 24-hour, 72-hour, one-week and two-week periods. Results On the 1st day, only MTA Fillapex caused cytotoxicity compared to negative control (NC) group (p<0.008). No significant difference was observed between the other tested materials at this period (p>0.05). After 14 days of incubation with the test materials, MTA Fillapex exhibited significantly higher cytotoxicity compared with iRoot SP, AH Plus Jet and the NC group (P<0.008). In the SEM analysis, the highest levels of cell attachment were observed for iRoot SP and the control group. After 24 hours, MTA Fillapex reduced the number of cells attached to the surface. Conclusions Within the limitations of this study, sealers exerted different cytotoxic effects on hTGSCs. Although all materials have exerted cellular toxicity, iRoot SP and AH Plus Jet may promote better attachment to hTGSCs. PMID:24037075

  16. Culture Human Mesenchymal Stem Cells With Calcium Phosphate Cement Scaffolds for Bone Repair

    PubMed Central

    Weir, Michael D.; Xu, Hockin H. K.

    2010-01-01

    Because of its moldability and excellent osteoconductivity, calcium phosphate cement (CPC) is highly promising for craniofacial and orthopedic applications. The objectives of this study were to investigate the response of human mesenchymal stem cells (hMSCs) to a high-strength CPC-chitosan scaffold and to examine cell proliferation and osteogenic differentiation. hMSCs were seeded onto CPC-chitosan composite, CPC control, and tissue culture polystyrene (TCPS). Alkaline phosphatase activity (ALP) and mineralization of hMSCs were measured. CPC-chitosan had a flexural strength (mean ± SD; n = 5) of (19.5 ± 1.4) MPa, higher than (8.0 ± 1.4) MPa of CPC control (p < 0.05). The percentage of live hMSCs on CPC-chitosan was (90.5 ± 1.3)% at 8 days, matching (90.7 ± 3.8)% of CPC control (p > 0.1). The CPC-chitosan surface area covered by the attached hMSCs increased from (51 ± 11)% at 1 day to (90 ± 4)% at 8 days (p < 0.05), matching those of CPC control (p > 0.1). Hence, the CPC strength was significantly increased via chitosan without compromising the hMSC response. At 8 days, there was a significant increase in ALP of cells in osteogenic media (10.99 ± 0.93) [(mM pNpp/min)/(μg DNA)] versus control media (3.62 ± 0.40) (p < 0.05). hMSCs in osteogenic media exhibited greater mineralization area of (47.5 ± 19.7)% compared with (6.1 ± 2.3)% in control medium on TCPS (p < 0.05). In conclusion, hMSCs showed excellent attachment and viability on the strong and tough CPC-chitosan scaffold, matching the hMSC response on CPC control. hMSCs were successfully differentiated down the osteogenic lineage. Hence, the strong, in situ hardening CPC-chitosan scaffold may be useful as a moderate load-bearing vehicle to deliver hMSCs for maxillofacial and orthopedic bone tissue engineering. PMID:20091907

  17. Periprosthetic bone density changes after MiniHipTM cementless femoral short stem: one-year results of dual-energy X-ray absorptiometry study

    PubMed Central

    Ercan, Ahmet; Sokkar, Sherif M.; Schmid, Gebhard; Filler, Timm J.; Abdelkafy, Ashraf; Jerosch, Joerg

    2016-01-01

    Introduction: The purpose of the current study was to investigate the reaction of the femur to the implantation of the MiniHipTM in terms of: (1) bone density change during one year; (2) correlations between stem length, CCD (caput-collum-diaphyseal), femoral offset, T-value, and bone density; (3) other co-variables that influence the change of bone density. Patients and methods: MiniHipTM implant was performed for 62 patients. The age range of the patients who underwent treatment was 25–78 years. Periprothestic bone density was determined within two weeks postoperatively, after three, six, and twelve months utilizing the DEXA scan. Results: The highest change was observed in the first three months post-implantation, while significant decrease in density was recorded at proximal Gruen zones 1, 2, and 7, and at distal Gruen zone 4. The decrease in density reached a plateau between the third and sixth months after operation. Afterwards, bone density recovered up to the 12th postoperative month. The correlation analysis showed significant difference between Gruen zone 1 and stem size and CCD. The same significant trend was not reached for Gruen zone 7. Femoral offset showed no correlation. Covariance analysis was unable to establish connection of the results with diagnosis, pairings, or gender. Discussion: MiniHipTM densitometric results are promising and comparable to good results of the other representatives of the femoral neck partially-sustaining short stem prostheses with a lower proximal bone density reduction. Periprosthetic bone resorption is a multifactorial process where stem size, CCD angle, and patient-specific variables such as T-value have an impact on the periprosthetic bone remodeling. In particular, this applies to Gruen zone 1. PMID:27855776

  18. Fully porous 3D printed titanium femoral stem to reduce stress-shielding following total hip arthroplasty.

    PubMed

    Arabnejad, Sajad; Johnston, Burnett; Tanzer, Michael; Pasini, Damiano

    2016-09-24

    Current hip replacement femoral implants are made of fully solid materials which all have stiffness considerably higher than that of bone. This mechanical mismatch can cause significant bone resorption secondary to stress shielding, which can lead to serious complications such as peri-prosthetic fracture during or after revision surgery. In this work, a high strength fully porous material with tunable mechanical properties is introduced for use in hip replacement design. The implant macro geometry is based off of a short stem taper-wedge implant compatible with minimally invasive hip replacement surgery. The implant micro-architecture is fine-tuned to locally mimic bone tissue properties which results in minimum bone resorption secondary to stress shielding. We present a systematic approach for the design of a 3D printed fully porous hip implant that encompasses the whole activity spectrum of implant development, from concept generation, multiscale mechanics of porous materials, material architecture tailoring, to additive manufacturing, and performance assessment via in vitro experiments in composite femurs. We show that the fully porous implant with an optimized material micro-structure can reduce the amount of bone loss secondary to stress shielding by 75% compared to a fully solid implant. This result also agrees with those of the in vitro quasi-physiological experimental model and the corresponding finite element model for both the optimized fully porous and fully solid implant. These studies demonstrate the merit and the potential of tuning material architecture to achieve a substantial reduction of bone resorption secondary to stress shielding. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

  19. Role of mesenchymal stem cells on differentiation in steroid-induced avascular necrosis of the femoral head

    PubMed Central

    Wang, Tiansheng; Teng, Shoufa; Zhang, Yingxia; Wang, Fa; Ding, Haijiao; Guo, Li

    2017-01-01

    Steroids are known to inhibit osteogenic differentiation and decrease bone formation in mesenchymal stem cells (MSCs), while concomitantly inducing steroid-induced avascular necrosis of the femoral head (SANFH). The aim of the present study was to evaluate the function of MSCs on differentiation in SANFH and investigate the pathobiological mechanisms underlying SANFH in a rabbit model. MSCs in the control, trauma-induced ANFH (TANFH) and SANFH groups were incubated with low-glucose complete Dulbeccos modified Eagles medium containing 10% fetal bovine serum. A number of adipocytes in the MSCs were stained with Sudan III and counted using a light microscope. The mRNA and protein expression levels of the adipose-specific 422 (AP2), peroxisome proliferator-activated receptor-γ (PPARγ), RUNX2, collagen type I (Col I) and miR-103 in the MSCs were determined using quantitative polymerase chain reaction and western blot analysis, respectively. In addition, the activities of osteocalcin (OC), alkaline phosphatase (ALP) and triglyceride (TG) in MSCs were analyzed using radioimmunoassay and determination kits. In the MSCs of the SANFH group, the mRNA and protein expression levels of AP2 and PPARγ were increased, while those of RUNX2 and Col I were reduced. Furthermore, the levels of OC and ALP activity in the MSCs of the SANFH group were decreased, and the activity of TG in the MSCs of the SANFH group was increased. In addition, the expression of miR-103 in the MSCs of the SANFH group was elevated. Following routine culture of the MSCs for 3 weeks, the number of adipocytes among the MSC population of the SANFH group was increased. Therefore, the results of the present study suggest that the osteogenic differentiation of MSCs in the SANFH was mitigated, while fat differentiation was promoted, which provides a novel explanation for the pathological changes associated with SANFH. PMID:28352349

  20. Transcriptional profiling of human femoral mesenchymal stem cells in osteoporosis and its association with adipogenesis.

    PubMed

    Choi, Yong Jun; Song, Insun; Jin, Yilan; Jin, Hyun-Seok; Ji, Hyung Min; Jeong, Seon-Yong; Won, Ye-Yeon; Chung, Yoon-Sok

    2017-08-24

    Genetic alterations are major contributing factors in the development of osteoporosis. Osteoblasts and adipocytes share a common origin, mesenchymal stem cells (MSCs), and their genetic determinants might be important in the relationship between osteoporosis and obesity. In the present study, we aimed to isolate differentially expressed genes (DEGs) in osteoporosis and normal controls using human MSCs, and elucidate the common pathways and genes related to osteoporosis and adipogenesis. Human MSCs were obtained from the bone marrow of femurs from postmenopausal women during orthopedic surgeries. RNA sequencing (RNA-seq) was carried out using next-generation sequencing (NGS) technology. DEGs were identified using RNA-seq data. Ingenuity pathway analysis (IPA) was used to elucidate the common pathway related to osteoporosis and adipogenesis. Candidate genes for the common pathway were validated with other independent osteoporosis and obese subjects using RT-PCR (reverse transcription-polymerase chain reaction) analysis. Fifty-three DEGs were identified between postmenopausal osteoporosis patients and normal bone mineral density (BMD) controls. Most of the genetic changes were related to the differentiation of cells. The nuclear receptor subfamily 4 group A (NR4A) family was identified as possible common genes related to osteogenesis and adipogenesis. The expression level of the mRNA of NR4A1 was significantly higher in osteoporosis patients than in controls (p=0.018). The expression level of the mRNA of NR4A2 was significantly higher in obese patients than in controls (p=0.041). Some genetic changes in MSCs are involved in the pathophysiology of osteoporosis. The NR4A family might comprise common genes related to osteoporosis and obesity. Copyright © 2017. Published by Elsevier B.V.

  1. Effects of a discoloration-resistant calcium aluminosilicate cement on the viability and proliferation of undifferentiated human dental pulp stem cells.

    PubMed

    Niu, Li-na; Watson, Devon; Thames, Kyle; Primus, Carolyn M; Bergeron, Brian E; Jiao, Kai; Bortoluzzi, Eduardo A; Cutler, Christopher W; Chen, Ji-hua; Pashley, David H; Tay, Franklin R

    2015-11-30

    Discoloration-resistant calcium aluminosilicate cement has been formulated to overcome the timely problem of tooth discoloration reported in the clinical application of bismuth oxide-containing hydraulic cements. The present study examined the effects of this experimental cement (Quick-Set2) on the viability and proliferation of human dental pulp stem cells (hDPSCs) by comparing the cellular responses with commercially available calcium silicate cement (white mineral trioxide aggregate; WMTA) after different aging periods. Cell viability and proliferation were examined using assays that examined plasma membrane integrity, leakage of cytosolic enzyme, caspase-3 activity for early apoptosis, oxidative stress, mitochondrial metabolic activity and intracellular DNA content. Results of the six assays indicated that both Quick-Set2 and WMTA were initially cytotoxic to hDPSCs after setting for 24 h, with Quick-Set2 being comparatively less cytotoxic than WMTA at this stage. After two aging cycles, the cytotoxicity profiles of the two hydraulic cements were not significantly different and were much less cytotoxic than the positive control (zinc oxide-eugenol cement). Based on these results, it is envisaged that any potential beneficial effect of the discoloration-resistant calcium aluminosilicate cement on osteogenesis by differentiated hDPSCs is more likely to be revealed after outward diffusion and removal of its cytotoxic components.

  2. Effects of a discoloration-resistant calcium aluminosilicate cement on the viability and proliferation of undifferentiated human dental pulp stem cells

    PubMed Central

    Niu, Li-na; Watson, Devon; Thames, Kyle; Primus, Carolyn M.; Bergeron, Brian E.; Jiao, Kai; Bortoluzzi, Eduardo A.; Cutler, Christopher W.; Chen, Ji-hua; Pashley, David H.; Tay, Franklin R.

    2015-01-01

    Discoloration-resistant calcium aluminosilicate cement has been formulated to overcome the timely problem of tooth discoloration reported in the clinical application of bismuth oxide-containing hydraulic cements. The present study examined the effects of this experimental cement (Quick-Set2) on the viability and proliferation of human dental pulp stem cells (hDPSCs) by comparing the cellular responses with commercially available calcium silicate cement (white mineral trioxide aggregate; WMTA) after different aging periods. Cell viability and proliferation were examined using assays that examined plasma membrane integrity, leakage of cytosolic enzyme, caspase-3 activity for early apoptosis, oxidative stress, mitochondrial metabolic activity and intracellular DNA content. Results of the six assays indicated that both Quick-Set2 and WMTA were initially cytotoxic to hDPSCs after setting for 24 h, with Quick-Set2 being comparatively less cytotoxic than WMTA at this stage. After two aging cycles, the cytotoxicity profiles of the two hydraulic cements were not significantly different and were much less cytotoxic than the positive control (zinc oxide–eugenol cement). Based on these results, it is envisaged that any potential beneficial effect of the discoloration-resistant calcium aluminosilicate cement on osteogenesis by differentiated hDPSCs is more likely to be revealed after outward diffusion and removal of its cytotoxic components. PMID:26617338

  3. Immediate changes of bone density caused by the implantation of a femoral stem--a DEXA study. Ulf.Leichtle@med.uni-tuebingen.de.

    PubMed

    Leichtle, Ulf G; Leasure, Jeremi; Martini, Franz; Leichtle, Carmen I

    2011-01-01

    Considerable immediate periprosthetic bone density changes after implantation of femoral stems have been observed comparing DEXA measurements taken pre- and post-operatively. This is important in relation to the interpretation of DEXA studies. We analysed these density changes under standardised experimental conditions. Five human femora were implanted with a custom made femoral stem and ten femora with a standard cementless prosthesis. Densitometry was performed at various stages of implantation. Following rasping only slight density changes were noted (-2.7% to +0.7%). Comparing post-implantation and pre-operative measurements, all custom made stems with a proximal press-fit demonstrated clear increases in proximal periprosthetic bone density of +11% and +14%. In contrast, the standard prosthesis with a distal press-fit showed a loss of -5% and -2% in the proximal zones. Measurements following removal of the implants demonstrated hardly any density changes (0% to -4%) compared to the pre-operative measurements. We concluded that compacting of trabecular bone or bone loss due to rasping are not the main causes of density changes. Substantial measuring errors exist. For examination of periprosthetic bone density changes, pre-operative initial measurements should not be used as a baseline for comparison. Studies should commence with an immediate postoperative measurement.

  4. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies.

    PubMed

    Yuan, Heng-Feng; Zhang, Jing; Guo, Chang-An; Yan, Zuo-Qin

    2016-02-01

    The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 - 0.32; p <0.001), a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p <0.01) and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 - 8.28; p<0.01). The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings.

  5. [Effects of low-frequency pulsed wave ultrasound on the shear properties of the interface of vancomycin-loaded acrylic bone cement-stem].

    PubMed

    Zhao, Q H; Zhu, F B; Cai, X Z; Yan, S G; He, R X

    2017-02-21

    Objective: To investigate the effects of low-frequency pulsed wave ultrasound on the shear properties of interface of the vancomycin -loaded acrylic bone cement-stem. Methods: The interfaces of 1% vancomycin-loaded acrylic bone cement-stem specimences were successfully manufactured and randomly divided into three groups: the control group, 450 mW/cm(2) ultrasound group and 1 200 mW/cm(2) ultrasound group, each group consisted of eight samples.Two ultrasound groups were exposed to a local ultrasonic field for 7 d, then immersed in PBS for 23 d, and the control groups were immersed in PBS for 30 d. After curing in air for 24 h, the shear strength of the stem-cement interface was determined by push-out test.The specimens were then photographed using SEM and analysed using Image-Pro Plus 6.0 to determine the porosity at the stem-cement interface. Results: The mean shear strength of stem-cement interface additionally decreased by 9% (P>0.05) and 17% (P<0.05) in 450 mW/cm(2) ultrasound group and 1 200 mW/cm(2) group respectively comparing with the control group, but no significant difference was found between the two ultrasound groups.The porosity at the stem-cement interface additionally increased by 44% (P>0.05) and 110% (P<0.05) in 450 mW/cm(2) ultrasound group and 1 200 mW/cm(2) group respectively comparing with the control group, furthermore.The porosity in 1 200 mW/cm(2) ultrasound group increased by 46% (P<0.05) comparing with the 450 mW/cm(2) group. There are much more fluid penetration along the stem-cement interface in ultrasound group . Conclusion: Low-frequency pulsed wave ultrasound signifiantly enhanced porosity and fluid penetration interface, and reduced the interface shear strength and initial stability.

  6. Exosomes from Human Synovial-Derived Mesenchymal Stem Cells Prevent Glucocorticoid-Induced Osteonecrosis of the Femoral Head in the Rat

    PubMed Central

    Guo, Shang-Chun; Tao, Shi-Cong; Yin, Wen-Jing; Qi, Xin; Sheng, Jia-Gen; Zhang, Chang-Qing

    2016-01-01

    Osteonecrosis of the femoral head (ONFH) represents a debilitating complication following glucocorticoid (GC)-based therapy. Synovial-derived mesenchymal stem cells (SMSCs) can exert protective effect in the animal model of GC-induced ONFH by inducing cell proliferation and preventing cell apoptosis. Recent studies indicate the transplanted cells exert therapeutic effects primarily via a paracrine mechanism and exosomes are an important paracrine factor that can be directly used as therapeutic agents for tissue engineering. Herein, we provided the first demonstration that the early treatment of exosomes secreted by human synovial-derived mesenchymal stem cells (SMSC-Exos) could prevent GC-induced ONFH in the rat model. Using a series of in vitro functional assays, we found that SMSC-Exos could be internalized into bone marrow derived stromal cells (BMSCs) and enhance their proliferation and have anti-apoptotic abilities. Finally, SMSC-Exos may be promising for preventing GC-induced ONFH. PMID:27766040

  7. In vitro measurement of bone-acrylic interface pressure during femoral component insertion.

    PubMed

    Markolf, K L; Amstutz, H C

    1976-01-01

    Bone-acrylic interface pressure measurements were recorded at the medial interior rasped surfaces of fresh cadaver femurs during digital packing of acrylic bone cement and during insertion and seating of a Trapezoidal-28 femoral total hip component. Plugging of the femoral canal below the tip of the prosthesis stem was an effective means for increasing pressure in the distal femoral canal when the stem was inserted in the early stages of acrylic polymerization (i.e. immediately after dough time). At surgery, this can be accomplished by inserting a small bolus of acrylic down the canal to a depth below the tip of the seated stem and allowing it to polymerize in place. This forms an effective seal which prevents distal extrusion of the acrylic when the cavity is then packed prior to prosthesis insertion. Elimination of cement in the distal canal also avoids any future difficulty of acrylic removal should revision become necessary due to loosening or infection. No significant pressure differences were observed between one and two millimeter thicknesses of acrylic between the metal and bone. Interface pressures developed during finger packing were of the same order of magnitude as those achieved during seating of the femoral component. Use of a rubber diaphragm stretched tightly over the margins of the rasped femoral cavity helped to contain the acrylic and prevent extrusion during finger packing but was ineffective in increasing interface pressure. When this method is used, the acrylic can be poured or injected into the canal and packed before dough stage and thus facilitate increased cancellous penetration when the acrylic is in a state of low viscosity.

  8. Shortening femoral osteotomy with stemmed resurfacing total knee arthroplasty for severe flexion contracture in Juvenile Rheumatoid Arthritis.

    PubMed

    Kitchen, Brock; Sanchez, Hugo B; Wagner, Russell A

    2015-06-01

    Juvenile Rheumatoid Arthritis (JRA) is a progressive disease characterized by pain, swelling, and loss of motion in the joints of adolescents. Total knee arthroplasty (TKA) can be indicated, during the adolescent years, in patients with advanced JRA to alleviate pain and improve function. Because of the relative infrequency of TKA in patients with JRA, evaluation of the type of TKA performed and the results merit review. This case report present two distinct operations performed to obtain full extension. 1. Distal femoral resection with conversion to hinged arthroplasty. 2. Femoral shortening osteotomy with resurfacing TKA.

  9. Shortening femoral osteotomy with stemmed resurfacing total knee arthroplasty for severe flexion contracture in Juvenile Rheumatoid Arthritis

    PubMed Central

    Kitchen, Brock; Sanchez, Hugo B.; Wagner, Russell A.

    2015-01-01

    Juvenile Rheumatoid Arthritis (JRA) is a progressive disease characterized by pain, swelling, and loss of motion in the joints of adolescents. Total knee arthroplasty (TKA) can be indicated, during the adolescent years, in patients with advanced JRA to alleviate pain and improve function. Because of the relative infrequency of TKA in patients with JRA, evaluation of the type of TKA performed and the results merit review. This case report present two distinct operations performed to obtain full extension. 1. Distal femoral resection with conversion to hinged arthroplasty. 2. Femoral shortening osteotomy with resurfacing TKA. PMID:25972704

  10. Outcomes of Charnley total hip arthroplasty using improved cementing with so-called second- and third-generation techniques.

    PubMed

    Hirose, Shiro; Otsuka, Hiromi; Morishima, Takkan; Sato, Keiji

    2012-03-01

    Techniques of cemented total hip arthroplasty have developed over time. We present the outcomes of Charnley total hip arthroplasty performed using improved second- and third-generation cementing techniques. We reviewed the radiologic results of 91 Charnley total hip arthroplasties performed using second- and third-generation cementing techniques. Second-generation techniques involved making multiple anchor holes, a double-cementing method on the acetabular side and an intramedullary plug, and retrograde filling with a cement gun on the femoral side in 57 hips. Third-generation techniques involved additional vacuum mixing and cement pressurization in 34 hips. Joint survival rates at 20 years when using second-generation techniques were 89% for the socket and 94% for the stem with aseptic loosening as the end point; the survival rates at 10 years when using third-generation techniques were 97 and 100%, respectively. According to our radiographic evaluation system for the clear zone at 5 years, there was less clear zone in the acetabular side with the third-generation techniques than with second-generation techniques. In the femoral side, there was very little development of the clear zone, but the difference between generations was not significant. Second- and third-generation cementing techniques showed excellent survivorship. The clear zone scores at 5 years indicated that third-generation techniques were effective, especially in the acetabular side, and may produce better long-term results than second-generation techniques.

  11. Late fatigue fracture of a modern cemented [corrected] cobalt chrome stem for total hip arthroplasty: a report of 10 cases.

    PubMed

    Della Valle, Alejandro González; Becksaç, Burak; Anderson, John; Wright, Timothy; Nestor, Bryan; Pellicci, Paul M; Salvati, Eduardo A

    2005-12-01

    We report 10 fatigue fractures of a modern, cemented, cobalt chromium alloy stem (Osteonics Omnifit) for total hip arthroplasty occurring between 1995 and 2004. The primary total hip arthroplasties had been performed between 1989 and 1996. The average age at the time of surgery was 54 years (range, 34-70 years), and the average body mass index was 29 (range, 20-38). The time in situ of the prosthesis at the time of fracture averaged 8 years (range, 4-12 years). Intermediate follow-up radiographs before the fracture were available in 7 cases, all of which demonstrated loss of calcar support. Scanning electron microscopy of the fracture surfaces in 3 of the components showed porosity near the initiation site. Metallography of polished and etched cross sections near the fracture surface revealed large grain size. In the presence of a spontaneous onset of thigh pain at intermediate follow-up in patients with this stem, particularly if associated with loss of calcar support, a fatigue fracture should be considered.

  12. A novel strontium(II)-modified calcium phosphate bone cement stimulates human-bone-marrow-derived mesenchymal stem cell proliferation and osteogenic differentiation in vitro.

    PubMed

    Schumacher, M; Lode, A; Helth, A; Gelinsky, M

    2013-12-01

    In the present study, the in vitro effects of novel strontium-modified calcium phosphate bone cements (SrCPCs), prepared using two different approaches on human-bone-marrow-derived mesenchymal stem cells (hMSCs), were evaluated. Strontium ions, known to stimulate bone formation and therefore already used in systemic osteoporosis therapy, were incorporated into a hydroxyapatite-forming calcium phosphate bone cement via two simple approaches: incorporation of strontium carbonate crystals and substitution of Ca(2+) by Sr(2+) ions during cement setting. All modified cements released 0.03-0.07 mM Sr(2+) under in vitro conditions, concentrations that were shown not to impair the proliferation or osteogenic differentiation of hMSCs. Furthermore, strontium modification led to a reduced medium acidification and Ca(2+) depletion in comparison to the standard calcium phosphate cement. In indirect and direct cell culture experiments with the novel SrCPCs significantly enhanced cell proliferation and differentiation were observed. In conclusion, the SrCPCs described here could be beneficial for the local treatment of defects, especially in the osteoporotic bone.

  13. Segmental cement extraction system (SEG-CES) and the Ilizarov method in limb salvage procedure after total knee cemented prosthesis removal in a former osteosarcoma patient.

    PubMed

    Ottaviani, Giulia; Randelli, Pietro; Catagni, Maurizio A

    2005-10-01

    Survival of osteosarcoma has greatly improved in the past few decades. Knee prosthesis is a well-recognized limb salvage procedure for osteosarcoma of the distal end of the femur. One drawback is that prostheses have a limited life and prosthetic failure with the inherent high rate of reoperations remains a serious long-term problem for former osteosarcoma patients. The segmental cement extraction system (SEG-CES) is a technique to remove cement in arthroplasty revision, based on a cement-bone interface with a lower strength compared to the old cement-new cement interface. We report the case of a 32-year-old former osteosarcoma patient in whom the SEG-CES was applied to remove a long-stemmed total knee cemented prosthesis. The prosthesis was placed 17 years before for a recurrent telangiectatic osteosarcoma of the left femur. Thirteen years after the prosthesis implantation, the patient complained of knee instability, pain, and complete failure of the extensor apparatus. The extraction of the prosthesis was performed using cylindrical batters of diameter corresponding to the diameter of the axle, two hammer extractors clamping the prosthesis components between two jaws. Extraction of the periprosthetic cement in the femoral and tibial components was done using the SEG-CES technique. The successful prosthesis removal performed in this patient allowed us to perform an external fixation with bone lengthening and reconstruction by the Ilizarov method.

  14. Pro-osteogenic effects of fibrin glue in treatment of avascular necrosis of the femoral head in vivo by hepatocyte growth factor-transgenic mesenchymal stem cells

    PubMed Central

    2014-01-01

    Background Autologous transplantation of modified mesenchymal stem cells (MSCs) is a promising candidate for the treatment of the refractory clinical disease, avascular necrosis of the femoral head (ANFH). Our previous attempts by compounding MSCs with medical fibrin glue to treat ANFH in animal model have achieved excellent effects. However, the underlying molecular mechanism is unclear, especially on the transgenic gene expression. Methods Rabbit MSCs were isolated and compounded with fibrin glue. Following degrading of fibrin glue, proliferation, viability, expression of transgenic hepatocyte growth factor gene as well as osteogenic differentiation of MSCs were evaluated together with that of uncompounded MSCs. Fibrin glue-compounded MSCs were transplanted into the lesion of ANFH model, and the therapeutic efficacy was compared with uncompounded MSCs. One-Way ANOVA was used to determine the statistical significance among treatment groups. Results Fibrin glue compounding will not affect molecular activities of MSCs, including hepatocyte growth factor (HGF) secretion, cell proliferation and viability, and osteogenic differentiation in vitro. When applying fibrin glue-compounded MSCs for the therapy of ANFH in vivo, fibrin glue functioned as a drug delivery system and provided a sustaining microenvironment for MSCs which helped the relatively long-term secretion of HGF in the femoral head lesion and resulted in improved therapeutic efficacy when compared with uncompounded MSCs as indicated by hematoxylin-eosin staining and immunohistochemistry of osteocalcin, CD105 and HGF. Conclusion Transplantation of fibrin glue-compounding MSCs is a promising novel method for ANFH therapy. PMID:24885252

  15. Comparison of bone marrow mesenchymal stem cells and core decompression in treatment of osteonecrosis of the femoral head: a meta-analysis.

    PubMed

    Li, Xu; Xu, Xian; Wu, Wei

    2014-01-01

    The study aims to compare the clinical efficacy of core decompression (CD) and bone marrow mesenchymal stem cells (BMMSC) on the patients with osteonecrosis of the femoral head (ONFH). A detailed literature search of PubMed, MEDLINE and EMBASE, Springer, Elsevier Science Direct, Cochrane Library and Google scholar for all relevant papers published was performed. Pooled odds ratio (OR) or weighted mean differences (WMD) and 95% confidence interval (CI) were used to evaluate the clinical efficacy of CD and BMMSC with the clinical outcome on the patients with ONFH. A total of 219 hips in 4 studies were indentified in this current meta-analysis. The OR of 2 separate studies consisting of 115 hips (CD group 63 hips; BMMSC group 52 hips) of patients were pooled and suggested BMMSC group had significantly less number of progressed vascularized bone grafting events than CD group (OR = 0.11; 95% CI: 0.03~0.43; P < 0.01). In addition, WMD of other 2 separate studies consisting of 104 hips (CD group 52 hips; BMMSC group 52 hips) in patients were pooled, and significant differences (P < 0.01) in Harris Hip Score (HHS) were observed between these two treatment groups at the end of follow-up study, BMMSC group had significantly better clinical outcome than CD group (WMD = 8.69; 95% CI: 3.76~13.62; P < 0.01). BMMSC may perform a better therapeutic effect than CD on the patients with osteonecrosis of the femoral head.

  16. Proximal Femoral Reconstructions with Bone Impaction Grafting and Metal Mesh

    PubMed Central

    Comba, Fernando; Piccaluga, Francisco

    2009-01-01

    Extensive circumferential proximal cortical bone loss is considered by some a contraindication for impaction bone grafting in the femur. We asked whether reconstruction with a circumferential metal mesh, impacted bone allografts, and a cemented stem would lead to acceptable survival in these patients. We retrospectively reviewed 14 patients (15 hips) with severe proximal femoral bone defects (average, 12 cm long; 14 type IV and one type IIIB using the classification of Della Valle and Paprosky) reconstructed with this method. The minimum followup was 20 months (average, 43.2 months; range, 20–72 months). Preoperative Merle D’Aubigné and Postel score averaged 4.8 points. With revision of the stem as the end point, the survivorship of the implant was 100% at one year and 86.6% at 72 months. The mean functional score at last followup was 14.4 points. We observed two fractures of the metal mesh at 31 and 48 months in cases reconstructed with a stem that did not bypass the mesh. Dislocation (3 cases) and acute deep infection (3 cases) were the most frequent complications. Patients with complete absence of the proximal femur may be candidates for biological proximal femoral reconstructions using this salvage procedure. Bone impaction grafting must be a routine technique if this method is selected. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:19294476

  17. Fabrication of macroporous cement scaffolds using PEG particles: In vitro evaluation with induced pluripotent stem cell-derived mesenchymal progenitors.

    PubMed

    Sladkova, Martina; Palmer, Michael; Öhman, Caroline; Alhaddad, Rawan Jaragh; Esmael, Asmaa; Engqvist, Håkan; de Peppo, Giuseppe Maria

    2016-12-01

    Calcium phosphate cements (CPCs) have been extensively used in reconstructive dentistry and orthopedics, but it is only recently that CPCs have been combined with stem cells to engineer biological substitutes with enhanced healing potential. In the present study, macroporous CPC scaffolds with defined composition were fabricated using an easily reproduced synthesis method, with minimal fabrication and processing steps. Scaffold pore size and porosity, essential for cell infiltration and tissue ingrowth, were tuned by varying the content and size of polyethylene glycol (PEG) particles, resulting in 9 groups with different architectural features. The scaffolds were characterized for chemical composition, porosity and mechanical properties, then tested in vitro with human mesenchymal progenitors derived from induced pluripotent stem cells (iPSC-MPs). Biomimetic decellularized bone scaffolds were used as reference material in this study. Our manufacturing process resulted in the formation of macroporous monetite scaffolds with no residual traces of PEG. The size and content of PEG particles was found to affect scaffold porosity, and thus mechanical properties. Irrespective of pore size and porosity, the CPC scaffolds fabricated in this study supported adhesion and viability of human iPSC-MPs similarly to decellularized bone scaffolds. However, the architectural features of the scaffolds were found to affect the expression of bone specific genes, suggesting that specific scaffold groups could be more suitable to direct human iPSC-MPs in vitro toward an osteoblastic phenotype. Our simplistic fabrication method allows rapid, inexpensive and reproducible construction of macroporous CPC scaffolds with tunable architecture for potential use in dental and orthopedic applications.

  18. Modelling heat transfer in a bone-cement-prosthesis system.

    PubMed

    Hansen, Eskil

    2003-06-01

    The heat transfer in a general bone-cement-prosthesis system was modelled. A quantitative understanding of the heat transfer and the polymerization kinetics in the system is necessary because injury of the bone tissue and the mechanical properties of the cement have been suggested to be effected by the thermal and chemical history of the system. The mathematical model of the heat transfer was based on first principles from polymerization kinetics and heat transfer, rather than certain in vitro observed properties, which has been the common approach. Our model was valid for general three-dimensional geometries and an arbitrary bone cement consisting of an initiator and monomer. The model was simulated for a cross-section of a hip with a potential femoral stem prosthesis and for a cement similar to Palacos R. The simulations were conducted by using the finite element method. These simulations showed that this general model described an auto accelerating heat production and a residual monomer concentration, which are two phenomena suggested to cause bone tissue damage and effect the mechanical properties of the cement.

  19. 21 CFR 888.3353 - Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... linkage across-the-joint. The two-part femoral component consists of a femoral stem made of alloys to be... proximal end of the femoral stem is tapered with a surface that ensures positive locking with the spherical...

  20. 21 CFR 888.3353 - Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... linkage across-the-joint. The two-part femoral component consists of a femoral stem made of alloys to be... proximal end of the femoral stem is tapered with a surface that ensures positive locking with the spherical...

  1. Human embryonic stem cell-derived mesenchymal stem cell seeding on calcium phosphate cement-chitosan-RGD scaffold for bone repair.

    PubMed

    Chen, Wenchuan; Zhou, Hongzhi; Weir, Michael D; Tang, Minghui; Bao, Chongyun; Xu, Hockin H K

    2013-04-01

    Calcium phosphate cement (CPC) has in situ-setting ability and excellent osteoconductivity. Human embryonic stem cells (hESCs) are exciting for regenerative medicine due to their strong proliferative ability and multilineage differentiation capability. However, there has been no report on hESC seeding with CPC. The objectives of this study were to obtain hESC-derived mesenchymal stem cells (hESCd-MSCs), and to investigate hESCd-MSC proliferation and osteogenic differentiation on novel CPC with chitosan immobilized with RGD (CPC-chitosan-RGD). RGD was covalently bonded with chitosan, which was then incorporated into CPC. The CPC-chitosan-RGD scaffold had higher strength and toughness than CPC-chitosan control without RGD (p<0.05). hESCs were cultured to form embryoid bodies (EBs), and the MSCs were then migrated out of the EBs. Flow cytometry indicated that the hESCd-MSCs expressed typical surface antigen profile of MSCs. hESCd-MSCs had good viability when seeded on CPC scaffolds. The percentage of live cells and the cell density were significantly higher on CPC-chitosan-RGD than CPC-chitosan control. Scanning electron microscope examination showed hESCd-MSCs with a healthy spreading morphology adherent to CPC. hESCd-MSCs expressed high levels of osteogenic markers, including alkaline phosphatase, osteocalcin, collagen I, and Runx2. The mineral synthesis by the hESCd-MSCs on the CPC-chitosan-RGD scaffold was twice that for CPC-chitosan control. In conclusion, hESCs were successfully seeded on CPC scaffolds for bone tissue engineering. The hESCd-MSCs had good viability and osteogenic differentiation on the novel CPC-chitosan-RGD scaffold. RGD incorporation improved the strength and toughness of CPC, and greatly enhanced the hESCd-MSC attachment, proliferation, and bone mineral synthesis. Therefore, the hESCd-MSC-seeded CPC-chitosan-RGD construct is promising to improve bone regeneration in orthopedic and craniofacial applications.

  2. Comparison of human mesenchymal stem cells proliferation and differentiation on poly(methyl methacrylate) bone cements with and without mineralized collagen incorporation.

    PubMed

    Wu, Jingjing; Xu, Suju; Qiu, Zhiye; Liu, Peng; Liu, Huiying; Yu, Xiang; Cui, Fu-Zhai; Chunhua, Zhao Robert

    2016-01-01

    Poly(methyl methacrylate) bone cement is widely used in vertebroplasty, joint replacement surgery, and other orthopaedic surgeries, while it also exposed many problems on mechanical property and biocompatibility. Better performance in mechanical match and bone integration is highly desirable. Recently, there reported that incorporation of mineralized collagen into poly(methyl methacrylate) showed positive results in mechanical property and osteointegration ability in vivo. In the present study, we focused on the comparison of osteogenic behavior between mineralized collagen incorporated in poly(methyl methacrylate) and poly(methyl methacrylate). Human marrow mesenchymal stem cells are used in this experiment. Adhesion and proliferation were used to characterize biocompatibility. Activity of alkaline phosphatase was used to assess the differentiation of human marrow mesenchymal stem cells into osteoblasts. Real-time PCR was performed to detect the expression of osteoblast-related markers at messenger RNA level. The results show that osteogenic differentiation on mineralized collagen incorporated in poly(methyl methacrylate) bone cement is more than two times higher than that of poly(methyl methacrylate) after culturing for 21 days. Thus, important mechanism on mineralized collagen incorporation increasing the osteogenetic ability of poly(methyl methacrylate) bone cement may be understood in this concern.

  3. Hemiarthroplasty for Displaced Femoral Neck Fractures in the Elderly Has a Low Conversion Rate.

    PubMed

    Grosso, Matthew J; Danoff, Jonathan R; Murtaugh, Taylor S; Trofa, David P; Sawires, Andrew N; Macaulay, William B

    2017-01-01

    Hemiarthroplasty (HA) has been a mainstay treatment for displaced femoral neck fractures for many years. The purpose of this study was to report the conversion rate of HA to total hip arthroplasty (THA) for displaced femoral neck fractures and compare outcomes between implant constructs (bipolar vs unipolar), fixation options (cemented vs cementless stems), and age groups (<75 years vs ≥75 years). We retrospectively reviewed the results of a consecutive cohort of 686 patients who underwent HA for the treatment of femoral neck fractures at our institution between 1999 and 2013 with a minimum of 2-year follow-up. The overall component revision rate, including conversion to THA, revision HA, revision with open reduction internal fixation, and Girdlestone procedure, was 5.6% (39/686). Seventeen patients (2.5%) were converted from HA to THA at an average of 1.9 years after index procedure. A significantly lower conversion rate of 1.4% (7/499 patients) was found in the older patient cohort (≥75 years old) compared to 5.3% (11/187) in the younger cohort. The most common causes for conversion surgery to THA were acetabular wear (5 patients), aseptic loosening (4 patients), and periprosthetic fracture (3 patients). There was a significantly lower rate of periprosthetic fracture (0.4% vs 2.5%, P value .025) in the cemented implant group compared to the cementless group. We observed a higher rate of dislocations in the bipolar vs unipolar group (3.8% vs 1%, P value .02) and no other significant differences between these groups. We observed a low reoperation rate for this cohort of patients, relatively higher conversion rates for the younger population, fewer periprosthetic fractures with the use of cemented stems, and no advantage of bipolar over unipolar prostheses. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Periprosthetic femoral fractures and trying to avoid them: what is the contribution of femoral component design to the increased risk of periprosthetic femoral fracture?

    PubMed

    Carli, A V; Negus, J J; Haddad, F S

    2017-01-01

    Periprosthetic femoral fractures (PFF) following total hip arthroplasty (THA) are devastating complications that are associated with functional limitations and increased overall mortality. Although cementless implants have been associated with an increased risk of PFF, the precise contribution of implant geometry and design on the risk of both intra-operative and post-operative PFF remains poorly investigated. A systematic review was performed to aggregate all of the PFF literature with specific attention to the femoral implant used. A systematic search strategy of several journal databases and recent proceedings from the American Academy of Orthopaedic Surgeons was performed. Clinical articles were included for analysis if sufficient implant description was provided. All articles were reviewed by two reviewers. A review of fundamental investigations of implant load-to-failure was performed, with the intent of identifying similar conclusions from the clinical and fundamental literature. In total 596 articles were initially identified, with 34 being eligible for analysis. Aggregate analysis of 1691 PFFs in 342 719 primary THAs revealed a significantly higher number of PFFs with cementless femoral implants (p < 0.001). Single-wedge and double-wedge (fit-and-fill) femoral implants were associated with a threefold increase in PFF rates (p < 0.001) compared with anatomical, fully coated and tapered/rounded stems. Within cemented stems, loaded-taper (Exeter) stems were associated with more PFFs than composite-beam (Charnley) stems (p = 0.004). Review of the fundamental literature revealed very few studies comparing cementless component designs. Very few studies within the PFF literature provide detailed implant information. Cementless implants, specifically those of single-wedge and double-wedge, have the highest PFF rates in the literature, with most investigations recommending against their use in older patients with osteoporotic bone. This review illustrates the need

  5. Modelling the fibrous tissue layer in cemented hip replacements: experimental and finite element methods.

    PubMed

    Waide, V; Cristofolini, L; Stolk, J; Verdonschot, N; Boogaard, G J; Toni, A

    2004-01-01

    The long-term fixation of cemented femoral components may be jeopardised by the presence of a fibrous tissue layer at the bone-cement interface. This study used both experimental and finite element (FE) methods to investigate the load transfer characteristics of two types of cemented hip replacements (Lubinus SPII and Müller-Curved) with a fibrous tissue layer. The experimental part investigated six stems of each type, where these were implanted in composite femurs with a specially selected silicone elastomer modelling the soft interfacial layer. Two fibrous tissue conditions were examined: a layer covering the full cement mantle, representing a revision condition; and a layer covering the proximal portion of the cement mantle, representing a non-revised implant with partial debonding and fibrous tissue formation. The FE method was used to model the full fibrous tissue layer condition, for both implants. The layer was modelled as a homogeneous, linearly isotropic material. A cross-comparison was performed of the experimental and FE findings. Agreement between experimental and FE models was verified to be within 15%. Varying the stiffness parameter of the FE soft tissue layer had little influence on the cortical bone strains, though had considerable effect on the cement strains. Stress shielding occurred for both stems under both fibrous tissue conditions, with the greatest reduction around the calcar. However, the cortical bone strains were generally larger than those for the equivalent well-fixed stems. The fibrous tissue layer was not found to increase the general strain pattern of the cement mantle, though localised regions of high stress were detected.

  6. Gene expression responses to mechanical stimulation of mesenchymal stem cells seeded on calcium phosphate cement.

    PubMed

    Gharibi, Borzo; Cama, Giuseppe; Capurro, Marco; Thompson, Ian; Deb, Sanjukta; Di Silvio, Lucy; Hughes, Francis John

    2013-11-01

    The aim of the study reported here was to investigate the molecular responses of human mesenchymal stem cells (MSC) to loading with a model that attempts to closely mimic the physiological mechanical loading of bone, using monetite calcium phosphate (CaP) scaffolds to mimic the biomechanical properties of bone and a bioreactor to induce appropriate load and strain. Human MSCs were seeded onto CaP scaffolds and subjected to a pulsating compressive force of 5.5±4.5 N at a frequency of 0.1 Hz. Early molecular responses to mechanical loading were assessed by microarray and quantitative reverse transcription-polymerase chain reaction and activation of signal transduction cascades was evaluated by western blotting analysis. The maximum mechanical strain on cell/scaffolds was calculated at around 0.4%. After 2 h of loading, a total of 100 genes were differentially expressed. The largest cluster of genes activated with 2 h stimulation was the regulator of transcription, and it included FOSB. There were also changes in genes involved in cell cycle and regulation of protein kinase cascades. When cells were rested for 6 h after mechanical stimulation, gene expression returned to normal. Further resting for a total of 22 h induced upregulation of 63 totally distinct genes that were mainly involved in cell surface receptor signal transduction and regulation of metabolic and cell division processes. In addition, the osteogenic transcription factor RUNX-2 was upregulated. Twenty-four hours of persistent loading also markedly induced osterix expression. Mechanical loading resulted in upregulation of Erk1/2 phosphorylation and the gene expression study identified a number of possible genes (SPRY2, RIPK1, SPRED2, SERTAD1, TRIB1, and RAPGEF2) that may regulate this process. The results suggest that mechanical loading activates a small number of immediate-early response genes that are mainly associated with transcriptional regulation, which subsequently results in activation of a

  7. Using a scale-bridging technique to determine the effect of elastic properties on stress distribution around the femoral stem of an artificial hip joint with a simplified geometry

    NASA Astrophysics Data System (ADS)

    Jeong, C. U.; Lee, S.-C.; Rhee, H. N.; Park, K. S.; Choi, S.-H.

    2014-07-01

    A scale-bridging technique was used to investigate the effect of the elastic properties of β-Ti alloys on the stress distribution around the femoral stem of an artificial hip joint with a simplified geometry when under an external loading. The anisotropic elastic constants of single-crystalline β-Ti alloys (TN1: Ti-18.75 at% Nb, TN2: Ti-37.5 at% Nb, and TN3: Ti-43.75 at% Nb) were calculated using an ab-initio technique that was based on density functional theory calculation. The single-crystalline elastic constants calculated via the ab-initio technique were used to calculate the elastic constants of polycrystal β-Ti alloys using an elastic selfconsistent scheme. Finite element analysis based on the elastic constants of polycrystalline β-Ti alloys for a femoral stem was conducted to calculate the above-mentioned stress distribution. The model system consisting of a TN1 alloy exhibited a relatively high level of von Mises stress on the surface of cancellous and cortical bones compared to model systems consisting of TN2, TN3 alloys and commercial biomaterials (Ti-6Al-4V alloy and 316STS). The thickness of the cancellous bone between the femoral stem and the cortical bone affected the stress concentration on the surface of the cortical bone.

  8. Asymptomatic Pseudotumors in Patients with Taper Corrosion of a Dual-Taper Modular Femoral Stem: MARS-MRI and Metal Ion Study.

    PubMed

    Kwon, Young-Min; Khormaee, Sariah; Liow, Ming Han Lincoln; Tsai, Tsung-Yuan; Freiberg, Andrew A; Rubash, Harry E

    2016-10-19

    Modularity in total hip arthroplasty facilitates intraoperative restoration of patient anatomy. Although dual-taper modular total hip arthroplasty offers potential advantages for optimizing the hip center of rotation, it has been associated with modular taper corrosion. This corrosion has led to adverse local tissue reactions (pseudotumors) at the neck-stem junction and elevated metal-ion levels. However, the occurrence of taper-corrosion-related pseudotumors in patients who remain asymptomatic following total hip arthroplasty with a dual-taper modular femoral stem remains largely unknown. The aims of this study were (1) to determine the prevalence of asymptomatic pseudotumors by utilizing metal artifact reduction sequence magnetic resonance imaging (MARS-MRI) and (2) compare serum metal-ion levels between symptomatic and asymptomatic patients with a dual-taper modular stem total hip replacement. We performed a retrospective cross-sectional study of 97 consecutive patients who had been treated with a dual-taper modular femoral stem total hip arthroplasty. Eighty-three patients were stratified into symptomatic and asymptomatic groups and evaluated with MARS-MRI, measurement of serum metal-ion levels, and the University of California at Los Angeles (UCLA) functional hip score. The prevalence of pseudotumors as determined with MARS-MRI was 15% in our asymptomatic patients and 36% in the overall cohort. The median serum cobalt level and cobalt/chromium ratio were significantly higher in patients with a pseudotumor than in those without a pseudotumor (8.0 versus 2.0 μg/L [p = 0.004] and 10.3 versus 2.4 μg/L [p = 0.012], respectively). However, there was no significant difference in the serum cobalt level or cobalt/chromium ratio between symptomatic patients with a pseudotumor and asymptomatic patients with a pseudotumor (7.6 versus 6.2 μg/L [p = 0.37] and 8.3 versus 10.6 μg/L [p = 0.46], respectively). The UCLA scores of asymptomatic patients with a pseudotumor were

  9. Autologous Bone Marrow Mesenchymal Stem Cells Associated with Tantalum Rod Implantation and Vascularized Iliac Grafting for the Treatment of End-Stage Osteonecrosis of the Femoral Head

    PubMed Central

    Zhao, Dewei; Liu, Baoyi; Wang, Benjie; Yang, Lei; Xie, Hui; Huang, Shibo; Zhang, Yao; Wei, Xiaowei

    2015-01-01

    Tantalum rod implantation with vascularized iliac grafting has been reported to be an effective method for the treatment of young patients with osteonecrosis of the femoral head (ONFH) to avert the need for total hip arthroplasty (THA). However, there have been unsatisfactory success rates for end-stage ONFH. The authors describe a modified technique using bone marrow mesenchymal stem cells (BMMSCs) associated with porous tantalum rod implantation combined with vascularized iliac grafting for the treatment of end-stage ONFH. A total of 24 patients (31 hips) with end-stage ONFH were treated with surgery; ARCO IIIc stage was observed in 19 hips and ARCO IV stage was observed in 12 hips. All patients were followed for a mean time of 64.35 ± 13.03 months (range 26–78). Operations on only five hips were converted to THA. The joint-preserving success rate of the entire group was 89.47% for ARCO stage IIIc and 75% for ARCO stage IV. The mean Harris hip score of the 31 hips improved significantly from 38.74 ± 5.88 points (range 22–50) to 77.23 ± 14.75 points (range 33–95). This intervention was safe and effective in delaying or avoiding total hip replacement for end-stage ONFH. PMID:25802840

  10. Autologous bone marrow mesenchymal stem cells associated with tantalum rod implantation and vascularized iliac grafting for the treatment of end-stage osteonecrosis of the femoral head.

    PubMed

    Zhao, Dewei; Liu, Baoyi; Wang, Benjie; Yang, Lei; Xie, Hui; Huang, Shibo; Zhang, Yao; Wei, Xiaowei

    2015-01-01

    Tantalum rod implantation with vascularized iliac grafting has been reported to be an effective method for the treatment of young patients with osteonecrosis of the femoral head (ONFH) to avert the need for total hip arthroplasty (THA). However, there have been unsatisfactory success rates for end-stage ONFH. The authors describe a modified technique using bone marrow mesenchymal stem cells (BMMSCs) associated with porous tantalum rod implantation combined with vascularized iliac grafting for the treatment of end-stage ONFH. A total of 24 patients (31 hips) with end-stage ONFH were treated with surgery; ARCO IIIc stage was observed in 19 hips and ARCO IV stage was observed in 12 hips. All patients were followed for a mean time of 64.35 ± 13.03 months (range 26-78). Operations on only five hips were converted to THA. The joint-preserving success rate of the entire group was 89.47% for ARCO stage IIIc and 75% for ARCO stage IV. The mean Harris hip score of the 31 hips improved significantly from 38.74 ± 5.88 points (range 22-50) to 77.23 ± 14.75 points (range 33-95). This intervention was safe and effective in delaying or avoiding total hip replacement for end-stage ONFH.

  11. Establishment of Efficacy and Safety Assessment of Human Adipose Tissue-Derived Mesenchymal Stem Cells (hATMSCs) in a Nude Rat Femoral Segmental Defect Model

    PubMed Central

    Choi, Hyung Jun; Kim, Jong Min; Kwon, Euna; Che, Jeong-Hwan; Lee, Jae-Il; Cho, Seong-Ryul; Kang, Sung Keun; Ra, Jeong Chan

    2011-01-01

    Human adipose tissue-derived mesenchymal stem cell (hATMSC) have emerged as a potentially powerful tool for bone repair, but an appropriate evaluation system has not been established. The purpose of this study was to establish a preclinical assessment system to evaluate the efficacy and safety of cell therapies in a nude rat bone defect model. Segmental defects (5 mm) were created in the femoral diaphyses and transplanted with cell media (control), hydroxyapatite/tricalcium phosphate scaffolds (HA/TCP, Group I), hATMSCs (Group II), or three cell-loading density of hATMSC-loaded HA/TCP (Group III-V). Healing response was evaluated by serial radiography, micro-computed tomography and histology at 16 weeks. To address safety-concerns, we conducted a GLP-compliant toxicity study. Scanning electron microscopy studies showed that hATMSCs filled the pores/surfaces of scaffolds in a cell-loading density-dependent manner. We detected significant increases in bone formation in the hATMSC-loaded HA/TCP groups compared with other groups. The amount of new bone formation increased with increases in loaded cell number. In a toxicity study, no significant hATMSC-related changes were found in body weights, clinical signs, hematological/biochemical values, organ weights, or histopathological findings. In conclusion, hATMSCs loaded on HA/TCP enhance the repair of bone defects and was found to be safe under our preclinical efficacy/safety hybrid assessment system. PMID:21468254

  12. Comparison of two pressurisers for cementation of the proximal femur.

    PubMed

    Morishima, Takkan; Choy, Godwin G H; Crawford, Ross W; Wilson, Lance J

    2014-08-01

    To compare pressures generated by 2 different cement pressurisers at various locations in the proximal femur. Two groups of 5 synthetic femurs were used, and 6 pressure sensors were placed in the femur at 20-mm intervals proximally to distally. Cement was filled into the femoral canal retrogradely using a cement gun with either the half-moon pressuriser or the femoral canal pressuriser. Maximum pressures and pressure time integrals (cumulative pressure over time) of the 2 pressurisers were compared. At all sensors, the half-moon pressuriser produced higher maximum pressures and pressure time integrals than the femoral canal pressuriser, but the difference was significant only at sensor 1 (proximal femur). This may result in reduced cement interdigitation in the proximal femur. The half-moon pressuriser produced higher maximum cementation pressures and pressure time integrals than the femoral canal pressuriser in the proximal femur region, which is critical for rotational stability of the implant and prevention of implant fracture.

  13. Stem subsidence of polished and rough double-taper stems

    PubMed Central

    Yamada, Kengo; Hirosaki, Kenichi; Takano, Masahiro; Matsumoto, Tadami

    2009-01-01

    Background and purpose Many clinical reports have indicated that polished hip stems show better clinical results than rough stems of the same geometry. It is still unknown, however, what the mechanical effects are of different surface finishes on the cement at the cement-bone interface. We compared mechanical effects in an in vitro cemented hip arthroplasty model. Methods Two sizes of double-taper polished stems and matt-processed polished stems (rough stems) were fixed into composite femurs. A 1-Hz dynamic load was applied to the stems for 1 million cycles. An 8-h no-load period was set after every 16 h of load. Stem subsidence within the cement, and compressive force and horizontal cement creep at the cement-bone interface, were measured. Results Compared to rough stems, stem subsidence, compressive force and cement creep for polished stems were a maximum of 4, 12, and 7-fold greater, respectively. There was a strong positive correlation between stem subsidence and compressive force for polished stems. In contrast, a strong negative correlation was found between stem subsidence and compressive force for rough stems. There was also a statistically significant relationship between compressive force on the cement and cement creep for the polished stems, but no significant relationship was found for rough stems. Interpretation This is the first evidence that different surface finishes of stems can have different mechanical effects on the cement at the cement-bone interface. Stem subsidence in polished stems resulted in compressive force on the cement and cement creep. The mechanical effects that polished taper stems impart on cement at the cement-bone interface probably contribute to their good long-term fixation and excellent clinical outcome. PMID:19421909

  14. 3D real time methodology monitoring cement failures in THA.

    PubMed

    Qi, Gang; Li, Jihui; Mann, Kenneth A; Mouchon, W Paul; Hamstad, Marvin A; Salehi, Abraham; Whitten, Stephen A

    2004-12-01

    The present work proposed a methodology to monitor cement microcrack formation in the cemented femoral stem construct using the acoustic emission technique. This technique provides a unique means to automatically tally the number of microcracks, to visualize microcrack distribution, and to animate the progress of crack formation in a given time window of a fatigue test. In this work, the formulation of microcrack source location was derived and a computer program was developed specifically for the proposed application. The program was validated using computer simulation and standard pencil lead break tests. It was found that the mathematical errors complied with the acceptable minimal error. Based on the pencil lead break tests, the average technical error used to estimate the resolution of this technique was 4.7 mm at the present stage. The program was then used to monitor the fatigue damage in precoated cemented femoral hip constructs loaded for a total of more than five million cycles. Two types of microcrack activities were observed in the experiments: Type I and Type II microcracks. A Type I microcrack was a crack that was captured by four or more sensors, and therefore its location was defined uniquely by a set of coordinates. A Type II microcrack was a crack that was captured by three or less sensors, therefore it was unlocatable. Both counts of Type I and Type II microcrack were tallied with respect to the day of fatigue tests. Acoustic emission microcrack graphs were used to visualize the distribution of Type I microcracks in the construct. It was found that the Type I microcracks distributed mainly over the proximal third of the stem. The amount of microcrack events decreased significantly as the number of loading cycles increased.

  15. Femoral head fractures: hemiarthroplasty or total hip arthroplasty?

    PubMed

    Ullmark, Gösta

    2014-10-02

    Most femoral neck fractures are osteoporotic fractures in the elderly. The one-year mortality after neck fracture in this group is 24%.For hemiarthroplasty (HA) the bipolar heads have a risk reduction for reoperation due to acetabular erosion compared with monoblock heads. Surprisingly, the bipolar head had an increased reoperation risk for dislocation, infection and for periprosthetic fracture.Total hip arthroplasty (THA) after fracture has a four-fold raised risk for dislocation compared with THA after osteoarthritis. A larger head on the same neck (head to neck ratio) results in a theoretically larger range of movement and hence less risk for dislocation. The dual mobility bearing has, theoretically, the largest range of movement and good clinical results.Functional results are better for THA compared with HA. Arthroplasty for fracture has much better results compared with arthroplasty after a failed internal fixation; the risk for reoperation is more than doubled for the latter.A Swedish hip arthroplasty register study found a 20-fold higher risk for periprosthetic fracture when comparing uncemented HA with matt cemented HA. Also a polished cemented stem had 13½-fold higher risks compared with a matt.The mortality during the first day after surgery is higher for cemented compared with uncemented arthroplasties, but lower after one week, one month and one year. Analysing the time points together resulted in no difference.A matt cemented THA with a maximum head size, maybe dual mobility, has the best results, and is also for the low-demanding elderly.

  16. Fretting crevice corrosion of stainless steel stem-CoCr femoral head connections: comparisons of materials, initial moisture, and offset length.

    PubMed

    Gilbert, Jeremy L; Mehta, Manav; Pinder, Bryan

    2009-01-01

    Modular tapers continue to be used in a wide variety of orthopedic implants. In this study, stainless steel (ASTM F-1568) femoral hip stems combined with Co-Cr-Mo alloy heads (SS/CoCr) were tested in an in vitro fretting corrosion test set-up to assess the propensity for mechanically assisted corrosion. Three different aspects of the modular design were evaluated in this study: (1) material combination compared to CoCr/CoCr, (2) wet versus dry assembly for SS/CoCr couples, and (3) 0- and 6-mm head offset for SS/CoCr couples. Fretting corrosion tests over a range of cyclic loads up to 3300 N were performed, and continuous cyclic loading at 3300 N for 1 M cycles were performed on each group (n = 5). Fretting micromotion was measured as a function of cyclic load on select couples to detect the nature and extent of motion present. The results showed that SS/CoCr couples were more susceptible to fretting corrosion than CoCr/CoCr couples, that dry assembly does not prevent fretting corrosion from taking place but raises the onset load, and that 6-mm offset heads had higher visual evidence of fretting damage but showed mixed statistical results in terms of onset loads and OCP shifts and currents compared to the 0-mm offset samples. Current and voltage excursions over 1 million cycles tended to diminish towards their unloaded control levels but did not fully recover until cyclic loading ceased. Micromotion measurements indicated fretting motions in the range of 10-25 microm where 0-mm heads tended to piston on the trunion, while 6 mm heads tended to rock. (c) 2008 Wiley Periodicals, Inc.

  17. Long-Duration Spaceflight During the Bion-M1 Spaceflight Experiment Resulted in Significant Bone Loss in the Femoral Head and Alterations in Stem Cell Differentiation Potential in Male Mice

    NASA Astrophysics Data System (ADS)

    Blaber, Elizabeth; Almeida, Eduardo; Grigoryan, Eleonora; Globus, Ruth

    Scientific understanding of the effects of microgravity on mammalian physiology has been limited to short duration spaceflight experiments (10-15 days). As long duration and inter-planetary missions are being initiated, there is a great need to understand the long-term effects of spaceflight on various physiological processes, including stem cell-based tissue regeneration. Bion-M1, for the first time, enabled the possibility of studying the effects of 30-days of microgravity exposure on a mouse model with sufficient sample size to enable statistical analysis. In this experiment, we hypothesized that microgravity negatively impacts stem cell based tissue regeneration, such as bone remodeling and regeneration from hematopoietic and mesenchymal precursors, thereby resulting in tissue degeneration in mice exposed to spaceflight. To test this hypothesis we collected the pelvis and proximal femur from space-flown mice and asynchronous ground controls and analyzed bone and bone marrow using techniques including Microcomputed Tomography (MicroCT), and in-vitro differentiation and differentiating cell motility assays. To determine the effects of 30-days spaceflight on bone tissue mass, we used MicroCT to analyze the trabecular bone of the femoral head and the cortical bone of the femoral neck and mid-shaft. We found that spaceflight caused a 45% decrease in bone volume ratio, a 17% decrease in trabecular thickness, a 25% decrease in trabecular number, and a 17% increase in trabecular spacing of trabecular bone. Furthermore, structural model index and trabecular pattern factor were increased by 32% and 82% respectively indicating that 30-days spaceflight resulted not only in a large loss of trabecular bone but also in a decrease of bone strength indicators. Analysis of the femoral neck cortical bone showed an increase in marrow area and cortical porosity indicating an overall widening of the femoral neck. Interestingly, no significant alterations were found in the cortical

  18. Cement lines of secondary osteons in human bone are not mineral-deficient: new data in a historical perspective.

    PubMed

    Skedros, John G; Holmes, Jennifer L; Vajda, Eric G; Bloebaum, Roy D

    2005-09-01

    Using qualitative backscattered electron (BSE) imaging and quantitative energy dispersive X-ray (EDX) spectroscopy, some investigators have concluded that cement (reversal) lines located at the periphery of secondary osteons are poorly mineralized viscous interfaces with respect to surrounding bone. This conclusion contradicts historical observations of apparent highly mineralized (or collagen-deficient) cement lines in microradiographs. Such conclusions, however, may stem from unrecognized artifacts that can occur during scanning electron microscopy. These include specimen degradation due to high-energy beams and the sampling of electron interaction volumes that extend beyond target locations during EDX analysis. This study used quantitative BSE imaging and EDX analysis, each with relatively lower-energy beams, to test the hypothesis that cement lines are poorly mineralized. Undemineralized adult human femoral diaphyses (n = 8) and radial diaphyses (n = 5) were sectioned transversely, embedded in polymethyl methacrylate, and imaged in a scanning electron microscope for BSE and EDX analyses. Unembedded samples were also evaluated. Additional thin embedded samples were stained and evaluated with light microscopy and correlated BSE imaging. BSE analyses showed the consistent presence of a bright line (higher atomic number) coincident with the classical location and description of the cement line. This may represent relative hypermineralization or, alternatively, collagen deficiency with respect to surrounding bone. EDX analyses of cement lines showed either higher Ca content or equivalent Ca content when compared to distant osteonal and interstitial bone. These data reject the hypothesis that cement lines of secondary osteons are poorly mineralized.

  19. Femoral nerve dysfunction

    MedlinePlus

    Neuropathy - femoral nerve; Femoral neuropathy ... Craig EJ, Clinchot DM. Femoral neuropathy. In: Frontera WR, Silver JK, Rizzo TD Jr, eds. Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, Pain, and Rehabilitation . 3rd ...

  20. Bone cement

    PubMed Central

    Vaishya, Raju; Chauhan, Mayank; Vaish, Abhishek

    2013-01-01

    The knowledge about the bone cement is of paramount importance to all Orthopaedic surgeons. Although the bone cement had been the gold standard in the field of joint replacement surgery, its use has somewhat decreased because of the advent of press-fit implants which encourages bone in growth. The shortcomings, side effects and toxicity of the bone cement are being addressed recently. More research is needed and continues in the field of nanoparticle additives, enhanced bone–cement interface etc. PMID:26403875

  1. Managing periprosthetic femoral stem fractures.

    PubMed

    Rosenberg, Aaron G

    2006-06-01

    Periprosthetic fractures can be difficult to manage. The classification system developed in Vancouver is simple and useful in determining appropriate treatment. It takes into account the site of the fracture, the stability of the implant, and the surrounding bone stock, which are the important elements of the fracture and hip that determines treatment. Understanding this classification system should allow the practitioner to choose the appropriate treatment. In addition to fracture management skills, understanding how to perform a host of hip revision technique may also be required.

  2. Radiographic preoperative templating of extra-offset cemented THA implants: how reliable is it and how does it affect survival?

    PubMed

    Bachour, F; Marchetti, E; Bocquet, D; Vasseur, L; Migaud, H; Girard, J

    2010-11-01

    Securing femoral offset should in theory improve hip stability and abductor muscles moment arms. As problems arise mainly in case of originally increased offset (>40 mm), a range of extra-offset stems is available; the exact impact in terms of fixation, however, is not known. Extra-offset stems should more reliably reestablish original femoral offsets exceeding 40 mm than standard femoral components, limiting instability risk without possible adverse effect on fixation. To compare the ability of five commonly available femoral stem designs to restitute offset exceeding 40 mm, and to assess function and cement fixation at a minimum 6 years' follow-up in a stem conceived to reproduce such offset. A continuous series of 74 total hip replacements (THR) in hips with increased (>40 mm) femoral offset was studied. All underwent preoperative X-ray templating on Imagika™ software to assess offset reproduction by five models of stem: four standard, and one Lubinus SP2™ extra-offset stem. A retrospective clinical and X-ray study was conducted with a minimum 6 years' follow-up on the Lubinus SP2™ 117° stems used to try to reproduce offset in the 74 THRs. Apart from the increased (>40 mm) offset, the cervicodiaphyseal angle was consistently <135°, <130° in 60 femurs (81%) and <125° in 45 (60%). Planning showed the four standard stems to induce (>5mm femoral offset reduction in 50-83% of cases, versus only 25% with the Lubinus SP2™ 117°). All 74 hips received Lubinus SP2™ 117° stems: at a mean 78 months FU (range, 70-94 mo), their mean Postel-Merle d'Aubigné score was 17±1.8 (range, 13-18). Five of the 74 THRs underwent surgical revision: three cases of loosening, in which the stem was replaced, and two of instability, without change of stem. Loosening was not related to offset reproduction quality; two of the three cases were due to initial cementing defect, and the third occurred in a femur with previous history of two osteotomies. There were four cases of

  3. Design considerations for ceramic resurfaced femoral head: effect of interface characteristics on failure mechanisms.

    PubMed

    Pal, Bidyut; Gupta, Sanjay; New, Andrew M R

    2010-01-01

    Ceramic hip resurfacing may offer improved wear resistance compared to metallic components. The study is aimed at investigating the effects of stiffer ceramic components on the stress/strain-related failure mechanisms in the resurfaced femur, using three-dimensional finite element models of intact and resurfaced femurs with varying stem–bone interface conditions. Tensile stresses in the cement varied between 1 and 5 MPa. Postoperatively, 20–85% strain shielding was observed inside the resurfaced head. The variability in stem–bone interface condition strongly influenced the stresses and strains generated within the resurfaced femoral head. For full stem–bone contact, high tensile (151–158 MPa) stresses were generated at the cup–stem junction, indicating risk of fracture. Moreover, there was risk of femoral neck fracture due to elevated bone strains (0.60–0.80% strain) in the proximal femoral neck region. Stresses in the ceramic component are reduced if a frictionless gap condition exists at the stem–bone interface. High stresses, coupled with increased strain shielding in the ceramic resurfaced femur, appear to be major concerns regarding its use as an alternative material.

  4. Arthroplasty in Femoral Head Osteonecrosis

    PubMed Central

    Nam, Dong Cheol; Jung, Kwangyoung

    2014-01-01

    Osteonecrosis of the femoral head is a destructive joint disease requiring early hip arthroplasty. The polyethylene-metal design using a 22-mm femoral head component, introduced by Charnley in 1950, has been widely used for over half a century. Since then, different materials with the capacity to minimize friction between bearing surfaces and various cement or cementless insert fixations have been developed. Although the outcome of second and third generation designs using better bearing materials and technologies has been favorable, less favorable results are seen with total hip arthroplasty in young patients with osteonecrosis. Selection of appropriate materials for hip arthroplasty is important for any potential revisions that might become inevitable due to the limited durability of a prosthetic hip joint. Alternative hip arthroplasties, which include hemiresurfacing arthroplasty and bipolar hemiarthroplasty, have not been found to have acceptable outcomes. Metal-on-metal resurfacing has recently been suggested as a feasible option for young patients with extra physical demands; however, concerns about complications such as hypersensitivity reaction or pseudotumor formation on metal bearings have emerged. To ensure successful long-term outcomes in hip arthroplasty, factors such as insert stabilization and surfaces with less friction are essential. Understanding these aspects in arthroplasty is important to selection of proper materials and to making appropriate decisions for patients with osteonecrosis of the femoral head. PMID:27536561

  5. The use of femoral struts and impacted cancellous bone allograft in patients with severe femoral bone loss who undergo revision total hip replacement: a three- to nine-year follow-up.

    PubMed

    Buttaro, M A; Costantini, J; Comba, F; Piccaluga, F

    2012-02-01

    We determined the midterm survival, incidence of peri-prosthetic fracture and the enhancement of the width of the femur when combining struts and impacted bone allografts in 24 patients (25 hips) with severe femoral bone loss who underwent revision hip surgery. The pre-operative diagnosis was aseptic loosening in 16 hips, second-stage reconstruction in seven, peri-prosthetic fracture in one and stem fracture in one hip. A total of 14 hips presented with an Endoklinik grade 4 defect and 11 hips a grade 3 defect. The mean pre-operative Merle D'Aubigné and Postel score was 5.5 points (1 to 8). The survivorship was 96% (95% confidence interval 72 to 98) at a mean of 54.5 months (36 to 109). The mean functional score was 17.3 points (16 to 18). One patient in which the strut did not completely bypass the femoral defect was further revised using a long cemented stem due to peri-prosthetic fracture at six months post-operatively. The mean subsidence of the stem was 1.6 mm (1 to 3). There was no evidence of osteolysis, resorption or radiolucencies during follow-up in any hip. Femoral width was enhanced by a mean of 41% (19% to 82%). A total of 24 hips had partial or complete bridging of the strut allografts. This combined biological method was associated with a favourable survivorship, a low incidence of peri-prosthetic fracture and enhancement of the width of the femur in revision total hip replacement in patients with severe proximal femoral bone loss.

  6. Cytotoxic Effects of Various Mineral Trioxide Aggregate Formulations, Calcium-Enriched Mixture and a New Cement on Human Pulp Stem Cells

    PubMed Central

    Jaberiansari, Zahra; Naderi, Seddigheh; Tabatabaei, Fahimeh Sadat

    2014-01-01

    Introduction: This in vitro study compared the cytotoxic effects of three commercially available MTA formulations naming ProRoot MTA (PMTA), Angelus MTA (AMTA), and Root MTA (RMTA), with calcium-enriched mixture (CEM) cement and a new nanohybrid MTA (NMTA) on human dental pulp stem cells (DPSC). Methods and Materials: Four disc-shaped specimens of each material were prepared. After completion of setting, 2 different (neat and 1/2) elutes of the test materials were made. Then in each cavity of a 96-well plate, 3000 cells were seeded and incubated in a humidified incubator with 5% CO2 and 95% air at 37°C for 24 h. After this period, the culture medium of each well was replaced with 200 μL of test material elutes. Plain culture medium was used as the negative control and distilled water as the positive control group. Cell viability was assessed using 2, 5-diphenyl-SH-tetrazelium bromide colorimetric assay, aka Mosmann’s tetrazolium toxicity (MTT) assay, at three time intervals (24, 48, and 72 h after mixing). Data were analyzed using the ANOVA and Tukey’s post hoc test (P=0.05). Results: After 24 h, the viability of cells in neat concentration had no significant differences (P>0.05) except for the NMTA. However, CEM and AMTA, at 1/2 concentration exerted significant proliferative effects on cells. At 48 and 72-h intervals, significant proliferation of DPSCs was seen in all samples, except for the NMTA which exerted toxic effects on cells. Conclusion: All of the three commercial MTAs and CEM cement showed comparative biocompatibility. However, NMTA had cytotoxic effects on DPSCs at all the time intervals. PMID:25386208

  7. Pre-operative digital templating in cemented hip hemiarthroplasty for neck of femur fractures.

    PubMed

    Kwok, Iris H Y; Pallett, Scott J C; Massa, Edward; Cundall-Curry, Duncan; Loeffler, Mark D

    2016-03-01

    Pre-operative digital templating allows the surgeon to foresee any anatomical anomalies which may lead to intra-operative problems, and anticipate appropriate instruments and implants required during surgery. Although its role is well-established in successful elective total hip arthroplasty, little work has been done on its use in hip hemiarthroplasty in neck of femur fractures. We describe our initial experience of digital templating in 40 consecutive patients who have undergone cemented hip hemiarthroplasty, assessing templating accuracy between templated implant sizes to actual implant sizes. 81% of implanted heads were templated to within two head sizes, and 89% of implanted stems were templated to within two sizes. Although there was a moderately strong correlation of 0.52 between templated and actual head sizes, this correlation was not demonstrated in femoral stem sizes. Mean leg length discrepancy was -2.5mm (S.D. 8.5), and the mean difference in femoral offset between the operated and non-operated hip was -1mm (S.D. 4.4). Digital templating is a useful adjunct to the surgeon in pre-operative planning of hip hemiarthroplasty in the restoration of leg length and femoral offset. However, its accuracy is inferior to that of elective total hip arthroplasty. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Plate failure following plate osteosynthesis in periprosthetic femoral fractures.

    PubMed

    Boesmueller, Sandra; Baumbach, Sebastian F; Hofbauer, Marcus; Wozasek, Gerald E

    2015-10-01

    Increasing numbers of total knee and hip arthroplasties result in a growing number of periprosthetic femoral fractures (PPFF). PPFF with a stable stem component are treated commonly with plate osteosynthesis. Therefore plate failure is seen as a major complication. The aim of this retrospective study was to investigate the patients' outcome after plate failure. The database of a Level 1 trauma center was searched for all patients treated for a PPFF with plate osteosynthesis. Patients with plate failure were investigated specifically. Standard demographic data, details on initial arthroplasty, trauma, and treatment were recorded for all patients. All fractures were classified and their outcome reviewed. Seven (8.8%) out of 80 patients treated with plate osteosynthesis following PPFF met our inclusion criterion being plate failure. All these patients were female, with an average age at primary surgery of 74 ± 13 years and a mean follow-up of 885 days (range, 264-2549). Four patients suffered a PPFF after total hip arthroplasty (THA) (2 Vancouver Type B1 and 2 Type C) and three after total knee arthroplasty (TKA) (Lewis-Rorabeck Type II). Following plate failure, four patients healed uneventfully and three patients experienced complications such as pseudarthrosis, screw loosening, and further plate failure. In patients with poor bone quality, bone graft, bone cement, and bone biologics have to be considered in revision surgery. Furthermore, long-stem revision and tumor prosthesis are an additional solution.

  9. Optimizing Stability in Femoral Neck Fracture Fixation.

    PubMed

    Ye, Ye; Hao, Jiandong; Mauffrey, Cyril; Hammerberg, E Mark; Stahel, Philip F; Hak, David J

    2015-10-01

    Optimizing stability of femoral neck fracture fixation is important in obtaining a successful outcome. The mechanical problems and strategies for achieving optimal stability differ depending on patients' age and degree of osteoporosis. Femoral neck fractures in younger adults usually result from high-energy trauma and have a vertical fracture pattern. Strategies for optimizing fixation stability in this group include placing additional screws at right angles to the fracture plane and medial buttress plate augmentation. In elderly patients, screw position relative to the intact cortical femoral neck bone is of critical importance. Additional strategies for optimizing fixation stability in this group include the concept of length stable fixation, use of adjunctive calcium phosphate cement, and use of novel fixed angle fixation implants. Copyright 2015, SLACK Incorporated.

  10. Extensively coated cementless femoral components in revision hip arthroplasty.

    PubMed

    Greidanus, N; Antoniou, J; Paprosky, W

    2000-01-01

    A septic loosening and osteolysis can compromise the available host bone in patients requiring revision hip arthroplasty. Secure fixation of revision femoral components may not be possible if reliant only on proximal femoral bone for biologic fixation or cement interdigitation. The challenge for the revision arthroplasty surgeon is to find the best method to secure the implant in a femur with deficient bone proximally that will provide stability for load bearing and motion. In addition to providing stability, the implant must be durable and maintain long-term fixation. With over 16 years of experience with fully porous coated femoral revision implants, we have found that maximizing prosthetic-bone fit in the proximal femoral diaphyseal bone provides reliable long-term fixation in the majority of femoral revision cases.

  11. Extensively Coated Cementless Femoral Components in Revision Hip Arthroplasty.

    PubMed

    Greidanus, Nelson; Antoniou, John; Paprosky, Wayne

    2000-10-01

    A septic loosening and osteolysis can compromise the available host bone in patients requiring revision hip arthroplasty. Secure fixation of revision femoral components may not be possible if reliant only on proximal femoral bone for biologic fixation or cement interdigitation. The challenge for the revision arthroplasty surgeon is to find the best method to secure the implant in a femur with deficient bone proximally that will provide stability for load bearing and motion. In addition to providing stability, the implant must be durable and maintain long-term fixation. With over 16 years of experience with fully porous coated femoral revision implants, we have found that maximizing prosthetic-bone fit in the proximal femoral diaphyseal bone provides reliable long-term fixation in the majority of femoral revision cases.

  12. Slipped capital femoral epiphysis

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/000972.htm Slipped capital femoral epiphysis To use the sharing features on this page, please enable JavaScript. A slipped capital femoral epiphysis is a separation of the ball ...

  13. Nineteen year results of THA using modular 9 mm S-ROM femoral component in patients with small femoral canals.

    PubMed

    Drexler, Michael; Dwyer, Tim; Marmor, Meir; Abolghasemian, Mansour; Chakravertty, Rajesh; Chechik, Ofir; Cameron, Hugh U

    2013-10-01

    A retrospective analysis was undertaken of 30 consecutive THA performed in 25 patients with hypoplastic proximal femurs, who had received a 9-mm uncemented modular S-ROM stem. The mean patient age was 42 years (17-69 years), mean height was 152.5 cm (130-170.5 cm), mean weight was 63 kg (39-90 kg), and mean follow-up period was 19 years (range, 12-23 years). Subsidence was seen in 2 hips, with asymptomatic femoral osteolysis present in 11 hips; overall survival of the femoral stem was 93.3%, with two revisions of the femoral component required for aseptic loosening. After a mean follow-up of 19 years, the use of the S-ROM 9 mm femoral stem in the patient with the small femur was associated with a low revision rate due to aseptic loosening of the stem.

  14. Long-term results using the straight tapered femoral cementless hip stem in total hip arthroplasty: a minimum of twenty-year follow-up.

    PubMed

    Ateschrang, Atesch; Weise, Kuno; Weller, Siegfried; Stöckle, Ulrich; de Zwart, Peter; Ochs, Björn Gunnar

    2014-08-01

    We report the first long-term results of a prospective cohort study after total hip arthroplasty using the cementless Bicontact hip stem. Between 1987 and 1990, 250 total hip arthroplasties in 236 patients were performed using the cementless Bicontact hip stem. The average follow-up was 22.8 years (20.4-24.8) and average age at index surgery was 58.1 years. Eighty-one patients died and 9 were lost to follow-up. We noted 11 stem revisions revealing an overall Kaplan Meier survival rate of 95.0% (CI 95%: 91.1-97.2%). The average Harris Hip Score revealed 81 points (range 24-93). The Bicontact hip stem demonstrated high survival rates despite high ages and osteopenic changes, which are equivalent to other long-term reports of cementless stem fixation.

  15. Continuous distal migration and internal rotation of the C-stem prosthesis without any adverse clinical effects: an RSA study of 33 primary total hip arthroplasties followed for up to ten years.

    PubMed

    von Schewelov, T; Carlsson, A; Sanzén, L; Besjakov, J

    2014-05-01

    In 2005, we demonstrated that the polished triple-tapered C-stem at two years had migrated distally and rotated internally. From that series, 33 patients have now been followed radiologically, clinically and by radiostereometric analysis (RSA) for up to ten years. The distal migration within the cement mantle had continued and reached a mean of 2 mm (0.5 to 4.0) at ten years. Internal rotation, also within the cement mantle, was a mean 3.8° (external 1.6° to internal 6.6°) The cement mantle did not show any sign of migration or loosening in relation to the femoral bone. There were no clinical or radiological signs indicating that the migration or rotation within the cement mantle had had any adverse effects for the patients.

  16. [Experimental study of canine bone marrow mesenchymal stem cells combined with calcium phosphate cement for repair of mandibular bone defects in Beagle dogs].

    PubMed

    Hu, Yi-cheng; Liu, Xin; Shen, Ji-jia; He, Jia-cai; Chen, Qiao-er

    2014-08-01

    To evaluate the effects of bone marrow mesenchymal stem cells (BMSCs) combined with calcium phosphate cement (CPC) scaffold for repair of mandibular defect in Beagle dogs. BMSCs were isolated from Beagle dogs and cultured in DMEM plus 10% FBS. The induction effect was determined using alizarin red staining or alkaline phosphate staining at 14-day of culture. BMSCs were added to the CPC scaffold for animal experiments. In vivo, three critical size bone defects were surgically created in each side of the mandible. The bone defects were repaired with BMSCs-CPC (scaffolds with composite seeding cells), CPC (scaffold alone) or no materials (blank group). Two dogs were sacrificed at 4-week and 8-week after operation. Gross observation, X-ray imaging, histologic and histometric analyses were performed to evaluate the level of bone formation. Newly formed bones were detected within all defect sites after operation. The BMSCs-CPC group and CPC group showed increased bone formation compared with the blank group. The BMSCs-CPC group exhibited more bone formation and degradation of the material than the CPC group. The percentage of new bone in the BMSCs-CPC and CPC treated group were significantly higher than that in the control group (P<0.05), while the percentage of new bone in the BMSCs-CPC sites was higher than that in the CPC sites (P<0.01); the percentage of residual material in the BMSCs-CPC sites was lower than that in the CPC sites (P<0.01) 4 weeks and 8 weeks after operation. Using the theory of tissue engineering, BMSCs composite CPC compound is an effective method in promoting new bone regeneration, which has a positive influence on the bone space preservation.

  17. Effect of dental materials calcium hydroxide-containing cement, mineral trioxide aggregate, and enamel matrix derivative on proliferation and differentiation of human tooth germ stem cells.

    PubMed

    Guven, Esra Pamukcu; Yalvac, Mehmet Emir; Sahin, Fikrettin; Yazici, Munevver M; Rizvanov, Albert A; Bayirli, Gunduz

    2011-05-01

    Biocompatibility of pulp capping materials is important for successful use in dentistry. These materials should be nontoxic and permissive for proliferation and induction of odontogenic differentiation of pulp cells. The aim of our study was to evaluate the effects of enamel matrix derivative (EMD), mineral trioxide aggregate (MTA), and calcium hydroxide-containing cement (DYCAL) on proliferation and odontogenic differentiation of human tooth germ stem cells (hTGSCs) in which cells belonging to both pulp tissue and dental follicle exist. The 96-well plates, 24-well plates, and special chamber slides were coated with biomaterials for cell proliferation, differentiation, and scanning electron microscopy analysis. Odontogenic differentiation of hTGSCs was evaluated by analyzing mRNA expression of dentin sialophosphoprotein (DSPP) by real-time polymerase chain reaction expression analysis, measurement of alkaline phosphatase activity, and visualization of calcium depositions by von Kossa staining. Our results demonstrate that EMD is the best material in terms of inducing differentiation and proliferation of hTGSCs. DYCAL was found to be toxic to hTGSCs; however, EMD-coated DYCAL showed less toxicity. EMD-coated MTA was not efficient at inducing proliferation and differentiation. Pulp capping materials come in direct contact with dental pulp cells; thus, they require comprehensive evaluation of interactions between cells and biomaterials. Therefore, we cultured hTGSCs, capable of odontogenic differentiation, on pulp capping materials directly. Our results suggest that combination of capping materials with EMD would increase the quality of capping by increasing biocompatibility of capping materials. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. The suitability of an uncemented hydroxyapatite coated (HAC) hip hemiarthroplasty stem for intra-capsular femoral neck fractures in osteoporotic elderly patients: the Metaphyseal-Diaphyseal Index, a solution to preventing intra-operative periprosthetic fracture.

    PubMed

    Chana, Rishi; Mansouri, Reza; Jack, Chris; Edwards, Max R; Singh, Ravi; Keller, Carmel; Khan, Farid

    2011-11-18

    This study will seek to identify a measurable radiographic index, the Metaphyseal-Diaphyseal Index (MDI) score to determine whether intra-operative fracture in osteoporotic bone can be predicted.A 5 year prospective cohort of 560 consecutive patients, undergoing hemiarthroplasty (cemented or uncemented), was evaluated. A nested case-control study to determine risk factors affecting intra-operative fracture was carried out. The Vancouver Classification was used to classify periprosthetic fracture. The MDI score was calculated using radiographs from the uncemented group. As a control (gold standard), Yeung et al's Canal Bone Ratio (CBR) score was also calculated. From this, a receiver operating characteristic (ROC) curve was formulated for both scores and area under the curve (AUC) compared. Intra and inter-observer correlations were determined. Cost analysis was also worked out for adverse outcomes. Four hundred and seven uncemented and one hundred and fifty-three cemented stems were implanted. The use of uncemented implants was the main risk factor for intra-operative periprosthetic fracture. Sixty-two periprosthetic fractures occurred in the uncemented group (15.2%), nine occurred in the cemented group (5.9%), P < 0.001. The revision rate for sustaining a periprosthetic fracture (uncemented group) was 17.7%, P < 0.001 and 90 day mortality 19.7%, P < 0.03. MDI's AUC was 0.985 compared to CBR's 0.948, P < 0.001. The MDI score cut-off to predict fracture was 21, sensitivity 98.3%, specificity 99.8%, positive predictive value 90.5% and negative predictive value 98%. Multivariate regression analysis ruled out any other confounding factors as being significant. The intra and inter-observer Pearson correlation scores were r = 0.99, P < 0.001. JRI uncemented hemiarthroplasty has a significantly higher intra-operative fracture rate. We recommend cemented arthroplasty for hip fractures. We propose a radiographic system that may allow surgeons to select patients who are good

  19. The suitability of an uncemented hydroxyapatite coated (HAC) hip hemiarthroplasty stem for intra-capsular femoral neck fractures in osteoporotic elderly patients: the Metaphyseal-Diaphyseal index, a solution to preventing intra-operative periprosthetic fracture

    PubMed Central

    2011-01-01

    This study will seek to identify a measurable radiographic index, the Metaphyseal-Diaphyseal Index (MDI) score to determine whether intra-operative fracture in osteoporotic bone can be predicted. A 5 year prospective cohort of 560 consecutive patients, undergoing hemiarthroplasty (cemented or uncemented), was evaluated. A nested case-control study to determine risk factors affecting intra-operative fracture was carried out. The Vancouver Classification was used to classify periprosthetic fracture. The MDI score was calculated using radiographs from the uncemented group. As a control (gold standard), Yeung et al's Canal Bone Ratio (CBR) score was also calculated. From this, a receiver operating characteristic (ROC) curve was formulated for both scores and area under the curve (AUC) compared. Intra and inter-observer correlations were determined. Cost analysis was also worked out for adverse outcomes. Four hundred and seven uncemented and one hundred and fifty-three cemented stems were implanted. The use of uncemented implants was the main risk factor for intra-operative periprosthetic fracture. Sixty-two periprosthetic fractures occurred in the uncemented group (15.2%), nine occurred in the cemented group (5.9%), P < 0.001. The revision rate for sustaining a periprosthetic fracture (uncemented group) was 17.7%, P < 0.001 and 90 day mortality 19.7%, P < 0.03. MDI's AUC was 0.985 compared to CBR's 0.948, P < 0.001. The MDI score cut-off to predict fracture was 21, sensitivity 98.3%, specificity 99.8%, positive predictive value 90.5% and negative predictive value 98%. Multivariate regression analysis ruled out any other confounding factors as being significant. The intra and inter-observer Pearson correlation scores were r = 0.99, P < 0.001. JRI uncemented hemiarthroplasty has a significantly higher intra-operative fracture rate. We recommend cemented arthroplasty for hip fractures. We propose a radiographic system that may allow surgeons to select patients who are

  20. Non-rigid calcium phosphate cement containing hydrogel microbeads and absorbable fibres seeded with umbilical cord stem cells for bone engineering.

    PubMed

    TheinHan, Wahwah; Weir, Michael D; Simon, Carl G; Xu, Hockin H K

    2013-10-01

    The need for bone repair has increased as the population ages. Non-rigid calcium phosphate scaffolds could provide compliance for micro-motions within the tissues and yet have load-supporting strength. The objectives of this study were to: (a) develop a non-rigid calcium phosphate cement (CPC) with microbeads and fibre reinforcement; and (b) investigate human umbilical cord mesenchymal stem cell (hUCMSC) proliferation, osteodifferentiation and mineralization on non-rigid CPC for the first time. Non-rigid CPC was fabricated by adding extra tetracalcium phosphate in the traditional CPC and by incorporating chitosan, absorbable fibres and hydrogel microbeads. The non-rigid CPC-microbead scaffold possessed a strain-at-failure of 10.7%, much higher than the traditional CPC's strain of 0.05% which is typical for brittle bioceramics. Flexural strength of non-rigid CPC-microbead was 4-fold that of rigid CPC-microbead scaffold, while work-of-fracture (toughness) was increased by 20-fold. The strength of non-rigid CPC-microbead-fibre scaffold matched that of cancellous bone. hUCMSCs on non-rigid CPC proliferated from 100 cells/mm(2) at 1 day to 600 cells/mm(2) at 8 days. Alkaline phosphatase, osteocalcin and collagen gene expressions of hUCMSCs were greatly increased, and the cells synthesized bone minerals. hUCMSCs on non-rigid CPC-microbead-fibre constructs had higher bone markers and more mineralization than those on rigid CPC controls. In conclusion, this study developed the first non-rigid, in situ-setting calcium phosphate-microbead-fibre scaffold with a strain-at-failure exceeding 10%. hUCMSCs showed excellent proliferation, osteodifferentiation and mineralization on non-rigid CPC scaffold. The novel non-rigid CPC-hUCMSC construct with good strength, high strain-at-failure and toughness, as well as superior stem cell proliferation, osteodifferentiation and mineralization, is promising for load-bearing bone regeneration applications. Copyright © 2012 John Wiley

  1. Femoral bowing plane adaptation to femoral anteversion

    PubMed Central

    Akman, Alp; Demirkan, Fahir; Sabir, Nuran; Oto, Murat; Yorukoglu, Cagdas; Kiter, Esat

    2017-01-01

    Background: Femoral bowing plane (FBP) is the unattended subject in the literature. More over the femoral shaft with its bowing is neglected in established anteversion determination methods. There is limited information about the relationship between FBP and anteversion. Thus we focused on this subject and hypothesized that there could be an adaptation of FBP to anteversion. Materials and Methods: FBP is determined on three-dimensional solid models derived from the left femoral computerized tomography data of 47 patients which were taken before for another reason and comparatively evaluated with anteversion. There were 20 women and 27 men. The mean age of patients was 56 years (range 21–84 years). Results: The anteversion values were found as the angle between a distal condylar axis (DCA) and femoral neck anteversion axis (FNAA) along an imaginary longitudinal femoral axis (LFA) in the true cranio-caudal view. The FBP was determined as a plane that passes through the centre-points of three pre-determinated sections on the femoral shaft. The angles between DCA, FNAA and FBP were comparatively evaluated. The independent samples t-test was used for statistical analysis. At the end, it was found that FBP lies nearly perpendicular to the anteversion axis for the mean of our sample which is around 89° in females and 93° in males (range 78–102°). On the other hand, FBP does not lie close to the sagittal femoral plane (SFP); instead, there is an average 12.5° external rotation relative to the SFP. FBP is correlated well with anteversion in terms of FBP inclination from SFP and femoral torsion (i.e., angle between FBP and femoral neck anteversion axis (P < 0.001; r = 0.680 and r = −0.682, respectively). Combined correlation is perfect (R2 = 1) as the FBP, SFP, and posterior femoral plane forms a triangle in the cranio-caudal view. Conclusions: We found that FBP adapts to anteversion. As FBP lies close to perpendicularity for the mean, femoral component positioning

  2. Surface pretreatment for prolonged survival of cemented tibial prosthesis components: full- vs. surface-cementation technique

    PubMed Central

    Marx, Rudolf; Qunaibi, Mutaz; Wirtz, Dieter Christian; Niethard, Fritz Uwe; Mumme, Thorsten

    2005-01-01

    Background One of few persisting problems of cemented total knee arthroplasty (TKA) is aseptic loosening of tibial component due to degradation of the interface between bone cement and metallic tibial shaft component, particularly for surface cemented tibial components. Surface cementation technique has important clinical meaning in case of revision and for avoidance of stress shielding. Degradation of the interface between bone cement and bone may be a secondary effect due to excessive crack formation in bone cement starting at the opposite metallic surface. Methods This study was done to prove crack formation in the bone cement near the metallic surface when this is not coated. We propose a newly developed coating process by PVD layering with SiOx to avoid that crack formation in the bone cement. A biomechanical model for vibration fatigue test was done to simulate the physiological and biomechanical conditions of the human knee joint and to prove excessive crack formation. Results It was found that coated tibial components showed a highly significant reduction of cement cracking near the interface metal/bone cement (p < 0.01) and a significant reduction of gap formation in the interface metal-to-bone cement (p < 0.05). Conclusion Coating dramatically reduces hydrolytic- and stress-related crack formation at the prosthesis interface metal/bone cement. This leads to a more homogenous load transfer into the cement mantle which should reduce the frequency of loosening in the interfaces metal/bone cement/bone. With surface coating of the tibial component it should become possible that surface cemented TKAs reveal similar loosening rates as TKAs both surface and stem cemented. This would be an important clinical advantage since it is believed that surface cementing reduces metaphyseal bone loss in case of revision and stress shielding for better bone health. PMID:16262888

  3. Control of in vivo mineral bone cement degradation.

    PubMed

    Kanter, Britta; Geffers, Martha; Ignatius, Anita; Gbureck, Uwe

    2014-07-01

    The current study aimed to prevent the formation of hydroxyapatite reprecipitates in brushite-forming biocements by minimizing the availability of free Ca(2+) ions in the cement matrix. This was achieved by both maximizing the degree of cement setting to avoid unreacted, calcium-rich cement raw materials which can deliver Ca(2+) directly to the cement matrix after dissolution, and by a reduction in porosity to reduce Ca(2+) diffusion into the set cement matrix. In addition, a biocement based on the formation of the magnesium phosphate mineral struvite (MgNH4PO4·6H2O) was tested, which should prevent the formation of low-solubility hydroxyapatite reprecipitates due to the high magnesium content. Different porosity levels were fabricated by altering the powder-to-liquid ratio at which the cements were mixed and the materials were implanted into mechanically unloaded femoral defects in sheep for up to 10 months. While the higher-porosity brushite cement quantitatively transformed into crystalline octacalcium phosphate after 10 months, slowing down cement resorption, a lower-porosity brushite cement modification was found to be chemically stable with the absence of reprecipitate formation and minor cement resorption from the implant surface. In contrast, struvite-forming cements were much more degradable due to the absence of mineral reprecipitates and a nearly quantitative cement degradation was found after 10 months of implantation.

  4. Squeeze cementing

    SciTech Connect

    Ewert, D.P.; Kundert, D.P.; Dahl, J.A.; Dalrymple, E.D.; Gerke, R.R.

    1992-06-16

    This patent describes a method for terminating the flow of fluid from a portion of a subterranean formation into a wellbore. It comprises: placing within the wellbore adjacent the portion a volume of a slurry of hydraulic cement, permitting the volume to penetrate into the portion; and maintaining the slurry in the portion for a time sufficient to enable the slurry to form a rigid mass of cement in the portion.

  5. Large-volume leukapheresis using femoral venous access for harvesting peripheral blood stem cells with the Fenwal CS 3000 Plus from normal healthy donors: predictors of CD34+ cell yield and collection efficiency.

    PubMed

    Sohn, Sang Kyun; Kim, Jong Gwang; Chae, Yeo Soo; Kim, Dong Hwan; Lee, Nan Young; Suh, Jang Soo; Lee, Kyu Bo

    2003-01-01

    The current paper reports on the predicting factors associated with satisfactory peripheral blood stem cell collection and the efficacy of large-volume leukapheresis (LVL) using femoral vein catheterization to harvest PBSCs with Fenwal CS 3000 Plus from normal healthy donors for allogeneic transplantation. A total of 113 apheresis procedures in 57 patients were performed. The median number of MNCs, CD3+ cells, and CD34+ cells harvested per apheresis was 5.3 x 10(8)/kg (range, 0.3-11.0 x 10(8)/kg), 3.0 x 10(8)/kg (range, 0.2-6.6 x 10(8)/kg), and 7.9 x 10(6)/kg (range, 0.1-188.9 x 10(6)/kg), respectively. The median collection efficiency of MNCs and CD34+ cells was 49.8% and 49.7%, respectively. A highly significant correlation was found between the collected CD34+ cell counts and the pre-apheresis WBC counts in the donors (P = 0.013), and between the collected CD34+ cell counts and the pre-apheresis peripheral blood (PB) CD34+ cell counts (P<0.001). Harvesting at least >4 x 10(6)/kg CD34+ cells from the 1st LVL was achieved in 44 (77.2%) out of 57 donors and in 19 (90.5%) out of 21 donors with a PB-CD34+ cell count of >40/microl. There was no significant difference in the harvested MNC and CD34+ cell counts between the 1st and 2nd apheresis. The catheter-related complications included catheter obstruction (n = 2) and hematoma at the insertion site (n = 3). Accordingly, LVL using femoral venous access for allogeneic PBSC collection from normal healthy donors would appear to be safe and effective.

  6. Cement oscillation increases interlock strength at the cement-bone interface, with commentary.

    PubMed

    Wang, Yi; Han, Pengfei; Gu, Wenguang; Shi, Zuowei; Li, Dabin; Wang, Changli

    2009-05-01

    Modern cementing techniques aim to improve the interlock between bone and cement and to establish a durable interface. Cement penetration is generally believed to influence interface failure, but current methods for improving the cement-bone interface are inadequate. Oscillation is the reciprocated movement of an object through its balanced position, or the quantum physics of systematic fluctuation back and forth near an average value (or trimmed value). To increase the interlock strength at the cement-bone interface, we designed a cement oscillator according to the principles of vibrational mechanics. To evaluate the effect of oscillation on the quality of interlock strength at the cement-bone interface, we randomly divided 156 femoral bones of adult pigs into 2 groups, oscillated and control, and performed mechanical tests to assess interlock strength at the cement-bone interface. The filling effect of bone cement was observed and analyzed under a stereomicroscope, and then each oscillated femur was compared with a control femur. The interlock strength at the cement-bone interface in the oscillated group was significantly greater than in the control group (P<.05), and the filling effect in the oscillated group was also better than that in the control group (P<.05). Our findings show that oscillation of bone cement significantly increases interlock strength at the cement-bone interface, point the way for clinicians to develop a high-performance and pragmatic fixation technique for prostheses to increase interlock strength, and will be of considerable practical importance in helping to prevent aseptic loosening of cemented prostheses.

  7. Femoral impaction grafting

    PubMed Central

    Scanelli, John A; Brown, Thomas E

    2013-01-01

    Femoral impaction grafting is a reconstruction option applicable to both simple and complex femoral component revisions. It is one of the preferred techniques for reconstructing large femoral defects when the isthmus is non-supportive. The available level of evidence is primarily derived from case series, which shows a mean survivorship of 90.5%, with revision or re-operation as the end-point, with an average follow-up of 11 years. The rate of femoral fracture requiring re-operation or revision of the component varies between several large case series, ranging from 2.5% to 9%, with an average of 5.4%. PMID:23362469

  8. Cement Burns

    PubMed Central

    Alam, Munir; Moynagh, M.; Lawlor, C.

    2007-01-01

    Objective: Cement burns account for relatively few admissions to a burn unit; however, these burns deserve separate consideration because of special features of diagnosis and management. Cement burns, even though potentially disabling, have rarely been reported in literature. Methods: A retrospective review was performed of all patients admitted with cement burns injuries to the national burns unit at the St James's Hospital in Dublin, Ireland, over a 10-year period for the years 1996–2005. Results: A total of 46 patients with cement burns were admitted. The majority of patients were aged 16–74 years (mean age = 32 years). Eighty-seven percent of injuries occurred in an industrial and 13% in a domestic setting. The upper and lower extremities were involved in all the patients, and the mean total body surface area affected was 6.5%. The mean length of hospital stay was 21 days with a range of 1–40 days. Thirty-eight (82%) were surgically managed involving debridement and split-thickness skin graft (SSG) and four (9%) were conservatively managed. A further four did not have data available. Conclusion: Widespread inexperience in dealing with this group of cement burns patients and delays in referral to burns unit highlights the potential for greater levels of general awareness and knowledge in both prevention and treatment of these burns. As well, early debridement and split-thickness skin grafting at diagnosis constitutes the best means of reducing the high socioeconomic costs and allows for early return to work. PMID:18091981

  9. Retaining well-fixed cementless stem in the treatment of infected hip arthroplasty

    PubMed Central

    2013-01-01

    Background and purpose Two-stage reconstruction, reimplantation after removal of an infected prosthesis, has been considered to be the gold standard for treatment of infected hip arthroplasty. However, during the removal of a well-fixed femoral stem, the proximal femur can be damaged and a sequestrum can be formed, which might lead to chronic osteomyelitis and difficulty in reimplantation. We wanted to determine whether infection after hip arthroplasty can be treated without removal of a well-fixed stem. Methods We treated 19 patients who had an infection after hip replacement, but a well-fixed cementless stem, with 2-stage reconstruction. At the first stage, we removed the acetabular cup, the liner and the head, but not the stem. We then implanted a cup of cement spacer. After control of infection, we reimplanted the acetabular component and head. Results 2 patients did not undergo second-stage reconstruction because they were satisfied with the pain relief and the activity that they had with the cement-spacer implantation. The remaining 17 patients underwent the second-stage of the reconstruction using cementless arthroplasty. At a mean follow-up time of 4 (2–8) years, 15 of the patients had no recurrence of infection, with satisfactory clinical and radiographic outcome. Interpretation This second-stage reconstruction after retention of the stem could be an alternative treatment option for periprosthetic infection with a well-fixed stem. PMID:23621807

  10. Early subsidence of shape-closed hip arthroplasty stems is associated with late revision

    PubMed Central

    van der Voort, Paul; Pijls, Bart G; Nieuwenhuijse, Marc J; Jasper, Jorrit; Fiocco, Marta; Plevier, Josepha W M; Middeldorp, Saskia; Valstar, Edward R; Nelissen, Rob G H H

    2015-01-01

    Background and purpose Few studies have addressed the association between early migration of femoral stems and late aseptic revision in total hip arthroplasty. We performed a meta-regression analysis on 2 parallel systematic reviews and meta-analyses to determine the association between early migration and late aseptic revision of femoral stems. Patients and methods Of the 2 reviews, one covered early migration data obtained from radiostereometric analysis (RSA) studies and the other covered long-term aseptic revision rates obtained from survival studies with endpoint revision for aseptic loosening. Stems were stratified according to the design concept: cemented shape-closed, cemented force-closed, and uncemented. A weighted regression model was used to assess the association between early migration and late aseptic revision, and to correct for confounders. Thresholds for acceptable and unacceptable migration were determined in accordance with the national joint registries (≤ 5% revision at 10 years) and the NICE criteria (≤ 10% revision at 10 years). Results 24 studies (731 stems) were included in the RSA review and 56 studies (20,599 stems) were included in the survival analysis review. Combining both reviews for the 3 design concepts showed that for every 0.1-mm increase in 2-year subsidence, as measured with RSA, there was a 4% increase in revision rate for the shape-closed stem designs. This association remained after correction for age, sex, diagnosis, hospital type, continent, and study quality. The threshold for acceptable migration of shape-closed designs was defined at 0.15 mm; stems subsiding less than 0.15 mm in 2 years had revision rates of less than 5% at 10 years, while stems exceeding 0.15 mm subsidence had revision rates of more than 5%. Interpretation There was a clinically relevant association between early subsidence of shape-closed femoral stems and late revision for aseptic loosening. This association can be used to assess the safety of

  11. Use of a novel carbon fibre composite material for the femoral stem component of a THR system: in vitro biological assessment.

    PubMed

    Scotchford, Colin A; Garle, Michael J; Batchelor, J; Bradley, John; Grant, David M

    2003-11-01

    A novel, low elastic modulus femoral component for THR has been developed using a composite of polyetheretherketone and carbon fibre. The objectives of this study were to investigate human osteoblast-like cell and macrophage responses to this material in vitro. Cells were grown on composite discs and controls. Osteoblast attachment and proliferation was not significantly different to that on Ti6Al4V. The levels of alkaline phosphatase activity, Type I collagen production and osteocalcin production were not significantly different to that on Ti6Al4V by the end of the experimental period. Hydrogen peroxide production by macrophages was significantly less than that detected for cells cultured on copper, but was still greater than that detected for cells cultured on tissue culture plastic and Ti6Al4V. Beta-glucoronidase activity was not significantly different to that detected for cells cultured on tissue culture plastic. The in vitro biocompatibility assessment of this composite undertaken in this study showed initial osteoblast attachment at least comparable to that of the tissue culture plastic and Ti6Al4V controls, with proliferation similar to the controls at all time points up to 11 days. Alkaline phosphatase activity was similar to that of Ti6Al4V but reduced compared to tissue culture plastic controls. Whilst hydrogen peroxide production by macrophages was raised on composite surfaces compared to controls, beta-glucoronidase activity and osteoblastic production of Type I collagen and osteocalcin were similar to levels detected on Ti6Al4V.

  12. Iliopsoas tendonitis caused by overhang of a collared femoral prosthesis.

    PubMed

    Brew, Christopher J; Stockley, Ian; Grainger, Andrew J; Stone, Martin H

    2011-04-01

    Pain after total hip arthroplasty can be due to a variety of causes, one of the less common being iliopsoas tendonitis. We report an unusual case of iliopsoas tendonitis caused by overhang of the femoral calcar by a collared femoral prosthesis resulting in impingement on the iliopsoas tendon. An ultrasound-guided corticosteroid and local anesthetic diagnostic injection to the site of impingement confirmed the diagnosis with temporary symptom relief. Revision of the femoral stem to a collarless prosthesis resulted in immediate and complete resolution of symptoms.

  13. Intraoperative fracture of the femur in revision total hip arthroplasty with a diaphyseal fitting stem.

    PubMed

    Meek, R M Dominic; Garbuz, Donald S; Masri, Bassam A; Greidanus, Nelson V; Duncan, Clive P

    2004-03-01

    In revision total hip arthroplasty, intraoperative split fractures and cortical perforation fractures are becoming a more common concern with the increasing use of diaphyseal fitting cementless stems. The purpose of this study was to evaluate the risk factors and frequency of intraoperative fractures with the use of these stems and their effect on radiographic and functional outcomes. We performed a retrospective case-control study of 211 consecutive patients who had undergone revision hip arthroplasty with a diaphyseal fitting cementless stem between December 1998 and March 2002. Sixty-four patients sustained an intraoperative fracture of the femur. One hundred and fifteen patients were followed for a minimum of two years; function was analyzed with self-administered outcome questionnaires, and radiographs were evaluated for evidence of bone ingrowth into the femoral stem. Risk factors associated with an intraoperative fracture were a substantial degree of preoperative bone loss, a low femoral cortex-to-canal ratio, underreaming of the cortex, and the use of a large-diameter stem. The majority of the diaphyseal undisplaced linear fractures occurred at the distal end of an extended trochanteric osteotomy during stem insertion. Fracture due to cortical perforation occurred most often during cement removal. These intraoperative fractures had no significant effect on the functional outcome or radiographic evidence of bone ingrowth. There was a surprisingly high rate of intraoperative femoral fractures associated with the use of a diaphyseal fitting stem in revision total hip arthroplasty. Identification of risk factors such as preoperative bone loss and a low cortex-to-canal ratio may permit planning to avoid such fractures. However, the final functional and radiographic outcomes appear to have been unaffected by the fracture when it had been managed appropriately. Prognostic study, Level II-1 (retrospective cohort study). See Instructions to Authors for a complete

  14. Combination treatment of biomechanical support and targeted intra-arterial infusion of peripheral blood stem cells mobilized by granulocyte-colony stimulating factor for the osteonecrosis of the femoral head: a randomized controlled clinical trial.

    PubMed

    Mao, Qiang; Wang, Weidong; Xu, Taotao; Zhang, Shanxing; Xiao, Luwei; Chen, Di; Jin, Hongting; Tong, Peijian

    2015-04-01

    The objective of this study was to determine the benefits of combination treatment with mechanical support and targeted intra-arterial infusion of peripheral blood stem cells (PBSCs) mobilized by granulocyte-colony stimulating factor (G-CSF) via the medial circumflex femoral artery on the progression of osteonecrosis of the femoral head (ONFH). Fifty-five patients (89 hips) with early and intermediate stage ONFH were recruited and randomly assigned to combination treatment or mechanical support treatment (control group). All hips received mechanical support treatment (porous tantalum rod implantation). Then, hips in the combination treatment group were performed targeted intra-arterial infusion of PBSCs. At each follow-up, Harris hip score (HHS) and Association Research Circulation Osseous (ARCO) classification were used to evaluate the symptoms and progression of osteonecrosis. Total hip arthroplasty (THA) was assessed as an endpoint at each follow-up. At 36 months, 9 of the 41 hips (21.95%) in the control group progressed to clinical failure and underwent THA whereas only 3 of the 48 hips (6.25%) in the combination treatment group required THA (p = 0.031). Kaplan-Meier survival analysis showed a significant difference in the survival time between the two groups (log-rank test; p = 0.025). Compared to the control group, combination treatment significantly improved the HHS at 36 months (p = 0.003). At the final follow-up examination, radiological progression was noted in 13 of 41 hips (31.71%) for the control group, but in only 4 of 48 hips (8.33%) for the combination treatment group (p = 0.005). The overall collapse rates were 15.15% (5/33 hips) and 8.11% (3/37 hips) in the control and combination treatment groups, respectively. Targeted intra-arterial infusion of PBSCs is capable of enhancing the efficacy of biomechanical support in the treatment of ONFH. This clinical trial confirmed that the combination treatment might be a safe and feasible

  15. Arthroplasty using a custom-made cemented total hip prosthesis for an extensive giant cell tumor of the proximal femur: report of a patient followed up for over 30 years.

    PubMed

    Nakano, Shunji; Enishi, Tetsuya; Hasan, Mohamed Yehya; Hanaoka, Naoyoshi; Kawasaki, Yoshiteru; Egawa, Hiroshi; Kinoshita, Isamu; Yasui, Natsuo

    2009-09-01

    We report the case of a 26-year-old man who had a pathologic transtrochanteric fracture of the left femur due to a grade II giant cell tumor affecting the neck and the trochanteric area. This patient underwent complete resection of the tumor and arthroplasty using a custom-made cemented total hip prosthesis. The good radiologic and functional results of the surgery have been maintained for over 30 years without local recurrence or lung metastasis. Moreover, new bone formation was observed at the reattachment sites of abductors, iliopsoas tendons and vastus lateralis to the femoral component of the prosthesis although local bone resorption was detected at the upper lateral part of the femoral stem and zone I of the cup side.

  16. Biomechanical assays for the study of the effects of hip prostheses: application to the reconstruction of bone defects with femoral allografts.

    PubMed

    Francés, Alberto; Claramunt, Rafael; Cebrian, Juan-Luis; Marco, Fernando; Lópiz, Yaiza; Rullanç, Ramon Muiña; Ros, Antonio; López-Durán, Luis

    2013-08-01

    There is a need to study and validate the mechanical behavior of the bone-implant total hip prosthesis and the treatment of its complications with experimental studies due to the limitations showed by numerical methods. Epoxy resin replicas of a femur (stereolithography) and a mechanical validation were performed. We studied three cases: intact femur (Case 1); non-defective femur with non-cemented LD primary stem (Case 2); and femur with a cavitary defect, short cemented stem over an impacted allograft (Case 3). The test pieces were connected to 7 strain gauges. Three assays per piece were carried out with a vertical and oblique load (load-unload curves after a sequence between 0 and 145.9 N). We measured the k coefficient (distance from the natural state of the strains) and stability of the stem (flexion-compression by strain gauges 1, 2, 5, and 7 and transversal lengthening by strain gauges 3, 4, and 6). Results of the strain gauge analysis revealed linearity of results in all cases, and more so in load than in unload. Gauge 7 (proximal) revealed shortening in all cases. Gauges 2 and 5 provided qualitatively similar data due to a significant increase in rigidity. K coefficients were obtained with a nonsignificant difference when each of the test pieces was compared with Case 2. The results were reproducible in all 7 gauges. Observation of the load-unload curves in all the test pieces assayed shows that there are no variations in the pattern of behavior (when comparing the stability of a primary stem and a stem in the simulated reconstructed femoral defect. If these reconstructions are considered theoretically appropriate for giving primary stability to the stem--a sine qua non for the success of replacement surgery--then our study is novel.

  17. Lunar cement

    NASA Technical Reports Server (NTRS)

    Agosto, William N.

    1992-01-01

    With the exception of water, the major oxide constituents of terrestrial cements are present at all nine lunar sites from which samples have been returned. However, with the exception of relatively rare cristobalite, the lunar oxides are not present as individual phases but are combined in silicates and in mixed oxides. Lime (CaO) is most abundant on the Moon in the plagioclase (CaAl2Si2O8) of highland anorthosites. It may be possible to enrich the lime content of anorthite to levels like those of Portland cement by pyrolyzing it with lunar-derived phosphate. The phosphate consumed in such a reaction can be regenerated by reacting the phosphorus product with lunar augite pyroxenes at elevated temperatures. Other possible sources of lunar phosphate and other oxides are discussed.

  18. Total Hip Arthroplasty around the Inception of the Interface Bioactive Bone Cement Technique

    PubMed Central

    Oonishi, Hiroyuki; Kawahara, Ikuo

    2016-01-01

    Background To augment cement-bone fixation, Dr. Hironobu Oonishi attempted additional physicochemical bonding through interposition of osteoconductive crystal hydroxyapatite (HA) granules at the cement-bone interface in 1982. He first used the interface bioactive bone cement (IBBC) technique in 12 selected patients (12 hips) in 1982 (first stage) and followed them for 2 years. In 1985, the technique was applied in 25 total hip arthroplasty (THA) patients (second stage) and the effects were investigated by comparing the side with the IBBC technique and the other side without the IBBC technique. He has employed this technique in all THA patients since 1987 (third stage). Methods In the IBBC technique, HA granules (2 to 3 g) were smeared on the bone surface just before the acetabular and femoral components were cemented. In the first stage, 12 hips were operated using the IBBC technique in 1982. In the second stage, THA was performed without the IBBC technique on one side and with the IBBC technique on the other side within 1 year in 25 patients. In the third stage, THA was performed with the IBBC technique in 285 hips in 1987. Results In the first stage patients, implant loosening was not detected at 30 years after operation. In the second stage patients, revision was required in 7 hips without the IBBC technique due to cup loosening (5 hips) and stem loosening (2 hips), whereas no hip was revised after THA with the IBBC technique at 26 years after operation. In the third stage patients, the incidence of radiolucent lines and osteolysis was very few at 25 years after operation. Conclusions The long-term follow-up of THA performed around the inception of the IBBC technique has revealed low incidences of radiolucent lines, osteolysis, and revision surgery. PMID:27583104

  19. The Exeter Contemporary flanged cemented acetabular component in primary total hip arthroplasty.

    PubMed

    Maggs, J L; Smeatham, A; Whitehouse, S L; Charity, J; Timperley, A J; Gie, G A

    2016-03-01

    We report on the outcome of the Exeter Contemporary flanged cemented all-polyethylene acetabular component with a mean follow-up of 12 years (10 to 13.9). This study reviewed 203 hips in 194 patients. 129 hips in 122 patients are still in situ; 66 hips in 64 patients were in patients who died before ten years, and eight hips (eight patients) were revised. Clinical outcome scores were available for 108 hips (104 patients) and radiographs for 103 hips (100 patients). A retrospective review was undertaken of a consecutive series of 203 routine primary cemented total hip arthroplasties (THA) in 194 patients. There were no acetabular component revisions for aseptic loosening. Acetabular revision was undertaken in eight hips. In four hips revision was necessitated by periprosthetic femoral fractures, in two hips by recurrent dislocation, in one hip for infection and in one hip for unexplained ongoing pain. Oxford and Harris hip scores demonstrated significant clinical improvement (all p < 0.001). Radiolucent lines were present in 37 (36%) of the 103 acetabular components available for radiological evaluation. In 27 of these, the line was confined to zone 1. No component had migrated. Kaplan-Meier survivorship, with revision for aseptic loosening as the endpoint, was 100% at 12.5 years and for all causes was 97.8% (95% confidence interval 95.6 to 100) when 40 components remained at risk. The Exeter Contemporary flanged cemented acetabular component demonstrates excellent survivorship at 12.5 years. The Exeter Contemporary flanged cemented acetabular component has excellent clinical outcomes and survivorship when used with the Exeter stem in total hip arthroplasty. ©2016 The British Editorial Society of Bone & Joint Surgery.

  20. Cryogenics with cement microscopy redefines cement behavior

    SciTech Connect

    Mehta, S.; Jones, R. ); Caveny, B. )

    1994-10-03

    Cement microscopy (CM), cryogenics, environmental scanning microscopy (ESM), scanning electron microscopy (SEM), and other technologies are leading investigators to change their views on cement gelation, hydration, and retardation. Cement samples frozen in a nitrogen slush and viewed with an SEM present a more accurate picture of the setting process. Observations made through this technique have revolutionized ARCO Exploration and Production Technology's and Halliburton Energy Services' oil field cement procurement and slurry design. Findings from this joint study are expected to lead to: optimized waiting on cement (WOC) times; reduced planning and design time; optimized slurry retarder additions; optimized gel times to fit given situations; especially applicable to squeeze operations; improved cement selection (from vendors) for peak performance; and improved cement manufacture. The paper discusses the measuring methods and the findings on the following: cement voids, cement gelation, and retardation mechanisms. It also briefly discusses the impact these discoveries have on operations.

  1. Comparative study of technique to obtain stem cells from bone marrow collection between the iliac crest and the femoral epiphysis in rabbits.

    PubMed

    Eça, Lilian Piñero; Ramalho, Renata Belmonte; Oliveira, Isis Sousa; Gomes, Paulo Oliveira; Pontes, Paulo; Ferreira, Alice Teixeira; Mazzetti, Marcelo Paulo Vaccari

    2009-01-01

    To assess the technique for the collection of rabbit bone marrow stem cells from different regions to be used as an experimental model in regenerative medicine. Thirty rabbits were allocated into 2 groups: GROUP A, n=8, animals that underwent bone marrow blood (BMB) harvesting from the iliac crest; and including 22 rabbits that underwent BMB harvesting from the femur epiphysis. After harvesting, mononuclear cells were isolated by density gradient centrifugation (Ficoll - Histopaque). The number of mononuclear cells per ml was counted in a Neubauer chamber and cell viability was checked through Tripan Blue method. Harvesting from the iliac crest yielded an average of 1 ml of BMB and 3,6.10(6) cells/ml over 1 hour of surgery, whereas an average of 3ml of BMB and 11,79.10(6) cells./ml were obtained in 30 min from the femur epiphysis with a reduced animal death rate. The analysis for the obtention of a larger number of mononuclear cells/ml from rabbit bone marrow blood was more satisfactory in the femur epiphysis than in the iliac crest.

  2. Sculpting with Cement.

    ERIC Educational Resources Information Center

    Olson, Lynn

    1983-01-01

    Cement offers many creative possibilities for school art programs. Instructions are given for sculpting with fiber-cement and sand-cement, as well as for finishing processes and the addition of color. Safety is stressed. (IS)

  3. Sculpting with Cement.

    ERIC Educational Resources Information Center

    Olson, Lynn

    1983-01-01

    Cement offers many creative possibilities for school art programs. Instructions are given for sculpting with fiber-cement and sand-cement, as well as for finishing processes and the addition of color. Safety is stressed. (IS)

  4. Cementless femoral components should be made from cobalt chrome.

    PubMed

    Sotereanos, N G; Engh, C A; Glassman, A H; Macalino, G E; Engh, C A

    1995-04-01

    Before 1982, the authors performed 177 primary total hip arthroplasties using a single-sized, extensively porous-coated cobalt-chrome femoral prosthesis. The current status of 122 of these arthroplasties is known. Two femoral prostheses have been revised for late symptomatic loosening, 2 for stem fracture, and 1 for infection. From 1982 to 1984, 227 primary arthroplasties were performed using the same stem in multiple sizes. Of these cases, 171 are available for followup. One stem (0.6%) has been revised for symptomatic loosening. Large osteolytic femoral lesions (average size, 8.1 cm2) developed in 3 patients, associated with an unusually large amount of polyethylene wear of their acetabular components. These patients have been treated by exchange of the polyethylene liner within the porous-coated acetabular component and allografting of the osteolytic lesions. The femoral components were not exchanged because osteolysis had not eroded the integrity of the supporting bone-implant interface to a point where loosening occurred. Before 1987, 193 patients with loose femoral components were treated with revision total hip arthroplasty, also using an extensively porous-coated cobalt-chrome femoral stem of similar design. Ten (5.7%) patients have required rerevision of the femoral prosthesis. Six of these 10 rerevisions were performed because of symptomatic loosening. Ninety-three percent of the patients in the primary series had relief of their preoperative pain and have improved functional ability; 94.2% are satisfied with their results. In the revision series, 89.1% of the patients are free of pain and function better than preoperatively, and 89.6% are fully satisfied with their results.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. STEM?!?!

    ERIC Educational Resources Information Center

    Merrill, Jen

    2012-01-01

    The author's son has been an engineer since birth. He never asked "why" as a toddler, it was always "how's it work?" So that he wanted a STEM-based home education was no big surprise. In this article, the author considers what kind of curricula would work best for her complex kid.

  6. STEM?!?!

    ERIC Educational Resources Information Center

    Merrill, Jen

    2012-01-01

    The author's son has been an engineer since birth. He never asked "why" as a toddler, it was always "how's it work?" So that he wanted a STEM-based home education was no big surprise. In this article, the author considers what kind of curricula would work best for her complex kid.

  7. Cementing multilateral wells with latex cement

    SciTech Connect

    1997-08-01

    A multilateral well is a well with one or more branches or lateral sections extending from its main wellbore. The laterals can be openhole or cased hole. When laterals are cased hole, the cement integrity for casing support and zonal isolation is very important. When cementing the lateral sections of multilateral wells, it is important to use a cement with high strength and durability to support the liner throughout the life of the well and to support the lateral section. The cement column is subjected to various stresses when the cemented inner stub is cut. High tensile strength, flexural strength, and crack resistance are required. These properties are necessary to make a clean cut through the cement sheath that does not induce cracks in the cement column. Latex cement is commonly used for its gas-migration-control property.

  8. [Classification of femoral shaft fractures in hip arthroplasties].

    PubMed

    Baulot, E; Chabernaud, D; Grammont, P M

    1995-12-01

    Fractures of the femoral shaft around cemented hip prosthesis have become increasingly common and are difficult to manage. These fractures are often complex and may occur late after the insertion of a cemented prosthesis. They often occur in relation to cortical defects produced by cement and previous surgery. The main classifications already described can be divided into "anatomic" classifications (founded on the level of the fracture on the shaft: Parrish 1964, Ali Khan 1977, Van Elegem 1979) or into "prosthetic" classifications (founded on the level of the fracture with respect to the tip of the prosthesis: Johansson 1981, Bethea 1982, Cooke 1988). But these classifications give few guideliness to help the choice of the most appropriate form of treatment. The aim of treatment, which remains controversial, is to return to weight-bearing and mobility as promptly as possible so preventing the complications of immobilization which are frequent and serious in the often elderly population.

  9. Femoral neck preservation in total hip replacement.

    PubMed

    Pipino, F; Molfetta, L

    1993-01-01

    Preservation of the femoral neck in hip arthroplasty creates a particular biomechanical situation which is clearly different from what is found even after partial neck removal. The femoral neck consists in fact of a "cylinder of cortical bone" that can be used as the "base" for anchoring the stem to the femur, in contrast to the press-fit procedure or other solutions. The mechanical and biological advantages are as follows: 1) Primary triplanar stem stability, in particular rotational stability. Rotational movements of the stem are blocked by the tough lateral cortical cylinder of the neck. Resistance to varus-valgus stress and collapse is also increased vertically and frontally. 2) Proximal cortical fixation. Primary fixation of the stem is provided by the neck cortex, whereas its mid-distal part is merely held by the metaphyseal cancellous bone and the tip is undersized with respect to the medullary canal. 3) Stress loads distributed along physiological lines of stress. Retention of the neck permits preservation of the trabecular systems, along which the stress is distributed towards the diaphysis and the greater trochanter. 4) Elasticity of the bone-prosthesis system. Most of the stem is contained within the metaphyseal cancellous bone that lies between the prosthesis and the cortical bone, creating a bone-prosthesis module with variable and integrated elasticity. 5) Preservation of the bone-stock. The amount of residual bone following implant of the prosthesis increases, not only because of the presence of the femoral neck, but also as a result of the preservation of most of the metaphyseal cancellous bone. There is therefore greater bone-ingrowth, which is also favoured by the fewer changes in the endosteal blood supply. 6) Prosthesis revision is simpler, since the stem can easily be removed and a second neck resection performed. Our clinical and experimental studies, together with those of Freeman et al., confirm that the femoral neck is present for a long

  10. Expansive Cements

    DTIC Science & Technology

    1970-10-01

    sulfate (C), and free lime (C) as well as other known portland cement compounds. 9. Etiite (C6AS3H3 2 ) is the phase formed during the hydration of...hydroxide (CH), required for chemical combination originates by hydration of alite (C3 S), belite (C2 S), and hydration of free lime in both the... shrinkage was also observed when the specimens were moist cured to full exparn-on for a pericd of 33 days. The data regarding the effect of aggregate size on

  11. [Slipped capital femoral epiphysis].

    PubMed

    Klein, C; Haraux, E; Leroux, J; Gouron, R

    2017-03-01

    Slipped capital femoral epiphysis (SFCE) is a disorder of the hip, characterized by a displacement of the capital femoral epiphysis from the metaphysic through the femoral growth plate. The epiphysis slips posteriorly and inferiorly. SCFE occurs during puberty and metabolic and epidemiologic risk factors, such as obesity are frequently found. Most chronic slips are diagnosed late. Sagittal hip X-rays show epiphysis slip. In case of untreated SCFE, a slip progression arises with an acute slip risk. Treatment is indicated to prevent slip worsening. The clinical and radiological classification is useful to guide treatment and it is predictive of the prognosis. In situ fixation of stable and moderately displaced SCFE with cannulated screws gives excellent results. Major complications are chondrolysis and osteonecrosis and the major sequelae are femoroacetabular impingement and early arthritis.

  12. Biocompatibility of calcium phosphate bone cement with optimised mechanical properties: an in vivo study.

    PubMed

    Palmer, Iwan; Nelson, John; Schatton, Wolfgang; Dunne, Nicholas J; Buchanan, Fraser; Clarke, Susan A

    2016-12-01

    This work establishes the in vivo performance of modified calcium phosphate bone cements for vertebroplasty of spinal fractures using a lapine model. A non-modified calcium phosphate bone cement and collagen-calcium phosphate bone cements composites with enhanced mechanical properties, utilising either bovine collagen or collagen from a marine sponge, were compared to a commercial poly(methyl methacrylate) cement. Conical cement samples (8 mm height × 4 mm base diameter) were press-fit into distal femoral condyle defects in New Zealand White rabbits and assessed after 5 and 10 weeks. Bone apposition and tartrate-resistant acid phosphatase activity around cements were assessed. All implants were well tolerated, but bone apposition was higher on calcium phosphate bone cements than on poly(methyl methacrylate) cement. Incorporation of collagen showed no evidence of inflammatory or immune reactions. Presence of positive tartrate-resistant acid phosphatase staining within cracks formed in calcium phosphate bone cements suggested active osteoclasts were present within the implants and were actively remodelling within the cements. Bone growth was also observed within these cracks. These findings confirm the biological advantages of calcium phosphate bone cements over poly(methyl methacrylate) and, coupled with previous work on enhancement of mechanical properties through collagen incorporation, suggest collagen-calcium phosphate bone cement composite may offer an alternative to calcium phosphate bone cements in applications where low setting times and higher mechanical stability are important.

  13. Identification of femoral head center of bipolar hemiarthroplasy in radiostereometric analysis with elementary geometrical shape models.

    PubMed

    Tsukanaka, Masako; Röhrl, Stephan M; von Schewelov, Thord; Nordsletten, Lars

    2016-02-08

    Elementary geometrical shape (EGS) models are useful in radiostereometric analysis (RSA) on hip stems because tantalum markers attached to the stems can be omitted. In order to create an EGS model of a femoral stem, the center of the femoral head has to be identified. The contour of the femoral head is recommended to be used. However, the contour of the femoral head cannot be detected exclusively by computer if it is combined with a bipolar head or a metal cup. We therefore hypothesized that the contour of the outer head of bipolar hemiarthroplasty can be included in the EGS model as well as the femoral head contour. We calculated the time required for the detection of the contour, the precision of analysis and the stem micromotion at 2 years using the two different methods in the same picture set and compared the results. The detection of the bipolar head contour was 10 times faster than that of the femoral head contour. The precision for subsidence was 0.16 mm in EGS RSA with the femoral head contour, and 0.15 mm with the bipolar head contour (p=0.68). The precisions were comparable and clinically acceptable. There was no significant difference between the results of the 2-year micromotion with the two different methods. We conclude that this new method is applicable to measure stem micromotion of hemi-arthroplasty with EGS RSA and the method facilitates the Radiostereometric analysis.

  14. Design optimization of a prosthesis stem reinforcing shell in total hip arthroplasty.

    PubMed

    de Beus, A M; Hoeltzel, D A; Eftekhar, N S

    1990-08-01

    The use of a perforated, titanium funicular shell to support the proximal femoral cortex in total hip arthroplasty was evaluated with the aid of both analytical and numerical techniques. The principal interactions between the femoral cortex, the metal shell, the implant stem and the acrylic bone cement were modeled using beam on elastic foundations theory and two-dimensional elasticity theory. Subsequent formulation of this model as a nonlinear design optimization problem enabled the determination of the dimensions of the implant and reinforcing shell which minimized an objective function based on a simplified material failure criterion. Two cases were examined, each with two cervico-diaphyseal angles: case A: with a rigid contact between a proximal prosthesis collar and the calcar femorale and case B: no collar contact (a collarless prosthesis or post-operative loosening). Case A achieved an optimal solution at a stem diameter 11-23 percent of the cortex inner diameter, a stem length to diameter ratio of 12-40, shell diameter 22-53 percent and thickness 0.2-7.2 percent of the cortex inner diameter and thickness, respectively. Case B achieved an optimal solution at a stem diameter 67-92 percent of the cortex inner diameter, length to diameter ratio of 4-6, and no shell. In case A the collar support makes the type of internal fixation unimportant, while in the more realistic case B, the shell is not recommended.

  15. Proximal femoral replacement for the treatment of periprosthetic fractures.

    PubMed

    Klein, Gregg R; Parvizi, Javad; Rapuri, Venkat; Wolf, Christopher F; Hozack, William J; Sharkey, Peter F; Purtill, James J

    2005-08-01

    A periprosthetic fracture around the femoral component is a rare but potentially problematic complication after total hip arthroplasty. Reconstruction can be challenging, especially when severe bone stock deficiency is encountered. Proximal femoral replacement is one method of treating the severely deficient proximal part of the femur. The present report describes the outcomes of revision total hip arthroplasty with use of a proximal femoral replacement in a cohort of patients who had a Vancouver type-B3 periprosthetic fracture. With use of a computerized institutional database, all patients in whom a Vancouver type-B3 fracture (characterized by severe proximal bone deficiency and a loose femoral stem) had been treated with a proximal femoral replacement were identified. A modular femoral replacement with proximal porous coating had been used in all cases. The twenty-one patients who were identified had had a mean age of 78.3 years (range, fifty-two to ninety years) at the time of the index operation. The clinical and radiographic records of these patients were reviewed. At the time of the latest follow-up (mean, 3.2 years), all but one of the patients were able to walk and had minimal to no pain. Complications included persistent wound drainage that was treated with incision and drainage (two hips), dislocation (two hips), refracture of the femur distal to the stem (one hip), and acetabular cage failure (one hip). Despite a relatively high complication rate, we believe that proximal femoral replacement is a viable option for the treatment of periprosthetic fractures in older patients with severe bone deficiency. If a proximal femoral replacement is used, the stability of the hip must be tested diligently intraoperatively and a constrained acetabular liner should be utilized if instability is encountered. In order to enhance the bone stock, the proximal part of the femur, however poor in quality, should be retained for reapproximation onto the implant.

  16. Standard anatomical medullary locking (AML) versus tricalcium phosphate-coated AML femoral prostheses

    PubMed Central

    Johnston, D.W.C. (Bill); Davies, Donna M.; Beaupré, Lauren A.; Lavoie, Guy

    2001-01-01

    Objectives To compare the preliminary rate and amount of bony ingrowth and calcar resorption between patients receiving either a standard anatomical medullary locking (AML) or a tricalcium phosphate (TCP)-coated AML femoral prosthesis and to compare preliminary clinical results. Design A prospective, randomized, double-blind clinical trial. Setting An acute care tertiary institution. Patients Between January 1993 and March 1995, 92 patients underwent primary total hip arthroplasty (THA). They were randomized to 2 groups of 46 — a control group or a treatment group. Of the 46 subjects enrolled in each group, no significant differences were seen preoperatively with respect to age, sex, diagnosis, clinical and radiographic assessment. Seventy-one patients were followed up for 24 months. Interventions Insertion of either a standard AML femoral implant (control group) or a TCP-coated AML femoral implant (treatment group). Outcome measures The degree of hypertrophy, calcar atrophy and the number of spot welds on standard postoperative radiographs at 6, 12 and 24 months. Clinically, assessment according to the Société internationale de chirurgie orthopédique et de traumatologie (SICOT) scale and a 100-point visual analogue scale (VAS) for pain. Results There were no prosthetic stem revisions in either group at the 24-month follow-up. Radiographically, bony ingrowth was not significantly different in the TCP-coated stem, by χ2 analysis of the degree of hypertrophy and number of spot welds present. Also by χ2 analysis, the degree of calcar atrophy was not significantly different between groups. The mean VAS score for pain at 24 months was 12.5 for the control and 12.1 for the treatment group. No significant differences were seen in any of the clinical categories of the SICOT Scale over the 24-month interval. Conclusion The objective of TCP-coating — to increase the rate and amount of bony ingrowth while reducing the rate of calcar resorption in non-cemented THA

  17. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-07-30

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, a comparison study of the three cement systems examined the effect that cement drillout has on the three cement systems. Testing to determine the effect of pressure cycling on the shear bond properties of the cement systems was also conducted. This report discusses testing that was performed to analyze the alkali-silica reactivity of ULHS in cement slurries.

  18. Cement design based on cement mechanical response

    SciTech Connect

    Thiercelin, M.J.; Dargaud, B.; Baret, J.F.; Rodriquez, W.J.

    1998-12-01

    The disappearance of cement bond log response as a result of variations of downhole conditions has been observed in numerous wells. This observation has led to concern about the loss of proper zonal isolation. Stresses induced in the cement, through deformation of the cemented casing resulting from the variation of downhole conditions, are the cause of this damage. The authors present an analysis of the mechanical response of set cement in a cased wellbore to quantify this damage and determine the key controlling parameters. The results show that the thermo-elastic properties of the casing, cement, and formation play a significant role. The type of failure, either cement debonding or cement cracking, is a function of the nature of the downhole condition variations. This analysis allows one to propose appropriate cement mechanical properties to avoid cement failure and debonding. The authors show that the use of high compressive strength cement is not always the best solution and, in some cases, flexible cements are preferred.

  19. Quantitative measurement of the stresses induced during polymerisation of bone cement.

    PubMed

    Roques, A; Browne, M; Taylor, A; New, A; Baker, D

    2004-08-01

    When bone cement cures, residual stresses due to bulk and thermal shrinkage will result. Present finite element (FE) simulations of implanted constructs often do not account for these stresses as an initial condition; this may lead to overestimations of the fatigue life of the cement. In the present study, an instrumented stem equipped with strain gauges and a thermocouple was employed to experimentally quantify the residual stresses induced as a result of bone cement curing within a simulated bone/cement/stem construct. Residual stresses as high as 10 MPa were observed in the cement mantle. Residual stresses of this magnitude are potentially high enough to initiate damage within the cement mantle or at the stem/cement interface immediately post-implantation. The acoustic emission technique has demonstrated that cracking and sliding mechanisms are occurring during curing, resulting in partial relaxation of these stresses. The implications for FE simulations of the implanted construct are discussed.

  20. Exactech Opteon Femoral Component Fracture 12 Years after Arthroplasty

    PubMed Central

    Patel, Shaun P.; Antoci, Valentin; Kadzielski, John J.; Vrahas, Mark S.

    2016-01-01

    Arthroplasty implant fracture is a rare but critical complication that requires difficult revision surgery, often with poor results, patient disability, and significant cost. Several reports show component fracture either at the stem or at the neck interface after a relatively short postoperative course. We report such failure after 12 years, suggesting no safe period after which femoral implant fracture does not occur. PMID:26955493

  1. [Distal femoral periprosthetic fractures: classification and therapy].

    PubMed

    Tomás, T; Nachtnebl, L; Otiepka, P

    2010-06-01

    Periprosthetic fracture is one of the most serious complication of total knee arthroplasty. In our retrospective clinical study we designed our classification with rules for treatment of those fractures. During the last thirty years we treated 53 distal femoral periprosthetic fractures in our orthopaedic department. In our clinical study we reviewed our group of distal femoral periprosthetic fractures with on the basis of X-ray findings, the treatment method used and treatment outcomes. According to our findings we divided distal femoral periprosthetic fractures into six groups: Type I Nondisplaced fractures, 5.7%; treatment failure rate, 33%. Type II a Fractures with lateral comminution (the most often type of fractures), 37.7%; treatment failure rate, 20%. Type II b Fractures with medial comminution, 7.5%; treatment failure rate, 60%. Type II c Fractures above TKA (the second most often type), 34%; treatment failure rate, 18%. Type II d Comminuted fractures, 5.7%; treatment failure rate, 18%. Type IIIFractures with loosening of TKA, 9.4%; treatment failure rate, 20%. For the treatment of fractures we used various methods according to the type of fracture: Plate osteosynthesis in 32 cases, with failure in seven. Three failures in IIa group due to incorrect osteosynthesis with condylar plate, treated by reosteosteosynthesis with same implant. One in IIb group treated primarily with cement plomb, after second failure treated with revision total knee arthroplasty. Two failures in IIc group, treated by reosteosynthesis with spongioplasty using the same implant. One failure in III group solved with revision TKA. Intramedullary nail in nine cases , with failure in two. One failure in IIb group treated by reosteosynthesis with condylar plate and cement plombage. One in IIc group due to infection, solved with extraction of material and second stage revision TKA. Conservative treatment in three cases,with failure in two. One in I group treated with condylar plate. One in

  2. Computational modelling of bone cement polymerization: temperature and residual stresses.

    PubMed

    Pérez, M A; Nuño, N; Madrala, A; García-Aznar, J M; Doblaré, M

    2009-09-01

    The two major concerns associated with the use of bone cement are the generation of residual stresses and possible thermal necrosis of surrounding bone. An accurate modelling of these two factors could be a helpful tool to improve cemented hip designs. Therefore, a computational methodology based on previous published works is presented in this paper combining a kinetic and an energy balance equation. New assumptions are that both the elasticity modulus and the thermal expansion coefficient depend on the bone cement polymerization fraction. This model allows to estimate the thermal distribution in the cement which is later used to predict the stress-locking effect, and to also estimate the cement residual stresses. In order to validate the model, computational results are compared with experiments performed on an idealized cemented femoral implant. It will be shown that the use of the standard finite element approach cannot predict the exact temporal evolution of the temperature nor the residual stresses, underestimating and overestimating their value, respectively. However, this standard approach can estimate the peak and long-term values of temperature and residual stresses within acceptable limits of measured values. Therefore, this approach is adequate to evaluate residual stresses for the mechanical design of cemented implants. In conclusion, new numerical techniques should be proposed in order to achieve accurate simulations of the problem involved in cemented hip replacements.

  3. Femoral bone marrow aspiration in live mice.

    PubMed

    Chung, Young Rock; Kim, Eunhee; Abdel-Wahab, Omar

    2014-07-05

    Serial sampling of the cellular composition of bone marrow (BM) is a routine procedure critical to clinical hematology. This protocol describes a detailed step-by-step technical procedure for an analogous procedure in live mice which allows for serial characterization of cells present in the BM. This procedure facilitates studies aimed to detect the presence of exogenously administered cells within the BM of mice as would be done in xenograft studies for instance. Moreover, this procedure allows for the retrieval and characterization of cells enriched in the BM such as hematopoietic stem and progenitor cells (HSPCs) without sacrifice of mice. Given that the cellular composition of peripheral blood is not necessarily reflective of proportions and types of stem and progenitor cells present in the marrow, procedures which provide access to this compartment without requiring termination of the mice are very helpful. The use of femoral bone marrow aspiration is illustrated here for cytological analysis of marrow cells, flow cytometric characterization of the hematopoietic stem/progenitor compartment, and culture of sorted HSPCs obtained by femoral BM aspiration compared with conventional marrow harvest.

  4. Strontium-containing hydroxyapatite bioactive bone cement in revision hip arthroplasty.

    PubMed

    Ni, G X; Chiu, K Y; Lu, W W; Wang, Y; Zhang, Y G; Hao, L B; Li, Z Y; Lam, W M; Lu, S B; Luk, K D K

    2006-08-01

    Clinical outcome of cemented implants to revision total hip replacement (THR) is not as satisfactory as primary THR, due to the loss of bone stock and normal trabecular pattern. This study evaluated a bioactive bone cement, strontium-containing hydroxyapatite (Sr-HA) bone cement, in a goat revision hip hemi-arthroplasty model, and compared outcomes with polymethylmethacrylate (PMMA) bone cement. Nine months after operation, significantly higher bonding strength was found in the Sr-HA group (3.36+/-1.84 MPa) than in the PMMA bone cement group (1.23+/-0.73 MPa). After detached from the femoral component, the surface of PMMA bone cement mantle was shown relatively smooth, whereas the surface of the Sr-HA bioactive bone cement mantle was uneven, by SEM observation. EDX analysis detected little calcium and no phosphorus on the surface of PMMA bone cement mantle, while high content of calcium (14.03%) and phosphorus (10.37%) was found on the surface of the Sr-HA bone cement mantle. Even higher content of calcium (17.37%) and phosphorus (10.84%) were detected in the concave area. Intimate contact between Sr-HA bioactive bone cement and bone was demonstrated by histological and SEM observation. New bone bonded to the surface of Sr-HA cement and grew along its surface. However, fibrous tissue was observed between PMMA bone cement and bone. The results showed good bioactivity of Sr-HA bioactive bone cement in this revision hip replacement model using goats. This in vivo study also suggested that Sr-HA bioactive bone cement was superior to PMMA bone cement in terms of bone-bonding strength. Use of bioactive bone cement may be a possible solution overcoming problems associated with the use of PMMA bone cement in revision hip replacement.

  5. Cementation and interface analysis of early failure cases after hip-resurfacing arthroplasty.

    PubMed

    Krause, Matthias; Breer, Stefan; Hahn, Michael; Rüther, Wolfgang; Morlock, Michael M; Amling, Michael; Zustin, Jozef

    2012-07-01

    The use of inappropriate cementation techniques has been suggested as an adverse factor for the long-term survival of hip-resurfacing arthroplasty. Inadequate initial fixation, thermal osteonecrosis and interface biological reactions are possible causes of failure. We analysed morphological changes associated with the cementation technique in a large collection of retrieved femoral components. One hundred and fifty femoral components (mean time to failure of 8.3 months±11.0) obtained at revision surgery were analysed morphometrically and histopathologically. Cement mantle and penetration were quantified in six different regions of interest. Histopathological analysis of the bone-cement interface was performed on undecalcified processed bone tissue. The vast majority of the cases differed substantially from laboratory-based cement-penetration depth recommendations. Fifty-nine cases had a fibrous membrane at the cement-bone interface. This membrane was significantly thicker in cases with osteonecrosis compared to cases viable bone. Our results demonstrate that most failures were cemented inappropriately. We suggest that poor cementation was an important adverse factor; however, the cause of the failures was obviously multifactorial. The thickness of the fibrous membrane at the cement-bone interface differed significantly between cases with osteonecrosis and specimens with viable bone tissue.

  6. Cement mixing with vibrator

    SciTech Connect

    Allen, T.E.

    1991-07-09

    This patent describes a method of cementing a casing string in a bore hole of a well. It comprises introducing water and dry cement material into a mixing vessel; mixing the water and dry cement material in the mixing vessel to form a cement slurry, the slurry including lumps of the dry cement material, the mixing including steps of: agitating the slurry; and while agitating the slurry, transmitting vibrational energy into the slurry and thereby aiding disintegration and subsequent wetting of the lumps of the dry cement material in the slurry; and pumping the slurry into an annulus between the casing string and the bore hole.

  7. In vivo performance of a reduced-modulus bone cement

    NASA Astrophysics Data System (ADS)

    Forehand, Brett Ramsey

    Total joint replacement has become one of the most common procedures in the area of orthopedics and is often the solution in patients with diseased or injured hip joints. Component loosening is a significant problem and is primarily caused by bone resorption at the bone-cement interface in cemented implants. It is our hypothesis that localized shear stresses are responsible for the resorption. It was previously shown analytically that local stresses at the interface could be reduced by using a cement of lower modulus. A new reduced modulus cement, polybutyl methylmethacrylate (PBMMA), was developed to test the hypothesis. PBMMA was formulated to exist as polybutyl methacrylate filler in a polymethyl methacrylate matrix. The success of PBMMA cement is based largely on the fact that the polybutyl component of the cement will be in the rubbery state at body temperature. In vitro characterization of the cement was undertaken previously and demonstrated a modulus of approximately one-eighth that of conventional bone cement, polymethyl methacrylate (PMMA) and increased fracture toughness. The purpose of this experiment was to perform an in vivo comparison of the two cements. A sheep model was selected. Total hip arthroplasty was performed on 50 ewes using either PBMMA or PMMA. Radiographs were taken at 6 month intervals. At one year, the contralateral femur of each sheep was implanted so that each animal served as its own control, and the animals were sacrificed. The stiffness of the bone-cement interface of the femoral component within the femur was assessed by applying a torque to the femoral component and demonstrated a significant difference in loosening between the cements when the specimens were tested in external rotation (p < 0.007). Evaluation of the mechanical data also suggests that the PBMMA sheep had a greater amount of loosening for each subject, 59% versus 4% for standard PMMA. A radiographic analysis demonstrated more signs of loosening in the PMMA series

  8. Asphalt cement poisoning

    MedlinePlus

    ... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

  9. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-10-31

    The objective of this project is to develop an improved ultra- lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries.

  10. Nondestructive evaluation of bone cement and bone cement/metal interface failure.

    PubMed

    Browne, M; Jeffers, J R T; Saffari, N

    2010-02-01

    To quantify the failure mechanisms related to the loosening of cemented hip joint replacements, novel techniques, capable of monitoring, nondestructively, the initiation and progression of failure during in vitro fatigue tests, were employed. Fatigue testing of model cement and cement-stem test pieces was monitored using acoustic emission (AE) sensors. Once damage was detected, an ultrasonic imaging system was used to obtain an image of the damage site and to measure the stiffness of the affected region. This method of examination provided a detailed insight into the internal crack propagation and delamination patterns. Initial work was conducted on bulk cement specimens subjected to bending and tension. The second stage of the work examined a model stem-cement interface under tensile opening loading conditions. A novel ultrasonic technique was used to measure the bond quality at the cement-metal interface. Progressive delamination was identified over time, and the AE technique was able to identify critical areas of delamination before they could be identified conclusively by ultrasonic imaging. The work has demonstrated the potential of the AE technique as a tool for the preclinical assessment of total hip replacements.

  11. Femoral nerve lesion in total hip replacement: an experimental study.

    PubMed

    Heller, K D; Prescher, A; Birnbaum, K; Forst, R

    1998-01-01

    A total of 20 hip joints of 10 non-fixed corpses were examined within 48 h of death to measure the pressure below the inguinal ligament simulating the surgical conditions during total hip arthroplasty. The purpose of this study was to assess the influence of various leg positions and insertion techniques of retractors during the surgical procedure for total hip replacement in order to detect supposed causes for indirect pressure injuries of the femoral nerve. The obtained results verified no increase of pressure in the inguinal canal which could explain an indirect injury of the femoral nerve. If the retractor is inserted correctly at the anterior acetabular rim, the pressure in the lacuna musculorum can even be reduced, and furthermore, the femoral nerve is protected by the iliopsoas muscle. Femoral nerve lesions which have been published so far can only be explained by an incorrect use of instruments or implants (e.g., screws, cement, acetabular cup) or an extreme postoperative leg length discrepancy.

  12. Prospective evaluation of femoral head viability following femoral neck fracture

    SciTech Connect

    Binkert, B.; Kroop, S.A.; Nepola, I.V.; Grantham, A.S.; Alderson, P.O.

    1984-01-01

    The bone scans of 33 patients (pts) with recent subcapital fractures (fx) of the femur were evaluated prospectively to determine their value in predicting femoral head visability. Each of the 33 pts (ll men, 22 women, age range 30-92) had a pre-operative bone scan within 72 hrs of the fx (23 pts within 24 hrs). Anterior and posterior planar views of both hips and pinhole views (50% of pts) were obtained 2 hrs after administration of Tc-99m HDP. The femoral head was classified as perfused if it showed the same activity as the opposite normal side or if it showed only slightly decreased activity. Femoral heads showing absent activity were classified as nonperfused. Overall, 20 of the 33 pts showed a photopenic femoral head on the side of the fx. Only 2 pts showed increased activity at hte site of the fx. Internal fixation of the fx was performed in 23 pts, 12 of whom had one or more follow-up scans. Five of these 12 pts showed absent femoral head activity on their initial scan, but 2 showed later reperfusion. The other 7 pts showed good perfusion initially, with only 1 later showing decreased femoral head activity. The other 10 pts (7 of whom had absent femoral head activity) had immediate resection of the femoral head and insertion of a Cathcart prosthesis. The results suggest that femoral head activity seen on a bone scan in the immediate post-fx period is not always a reliable indicator of femoral head viability. Decreased femoral head activity may reflect, in part, compromised perfusion secondary to post-traumatic edema, with or without anatomic disruption of the blood supply.

  13. Laparoscopic repair of femoral hernia

    PubMed Central

    Yang, Xue-Fei

    2016-01-01

    Laparoscopic repair of inguinal hernia is mini-invasive and has confirmed effects. Femoral hernia could be repaired through the laparoscopic procedures for inguinal hernia. These procedures have clear anatomic view in the operation and preoperatively undiagnosed femoral hernia could be confirmed and treated. Lower recurrence ratio was reported in laparoscopic procedures compared with open procedures for repair of femoral hernia. The technical details of laparoscopic repair of femoral hernia, especially the differences to laparoscopic repair of inguinal hernia are discussed in this article. PMID:27826574

  14. Porous Surface Modified Bioactive Bone Cement for Enhanced Bone Bonding

    PubMed Central

    Huang, Li; Dong, Jingjing; Guo, Dagang; Mao, Mengmeng; Kong, Liang; Li, Yang; Wu, Zixiang; Lei, Wei

    2012-01-01

    Background Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth. Materials and Methods The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant–bone interface was also investigated by push-out tests. Results The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony defect. Conclusions

  15. Intraoperative type 1 proximal femoral fractures: influence on the stability of hydroxyapatite-coated femoral components.

    PubMed

    Falez, F; Santori, N; Panegrossi, G

    1998-09-01

    We reviewed a series of 120 uncemented total hip replacements using the Omniflex stem with hydroxyapatite coating. Twenty minor intraoperative proximal fractures occurred. All fractures were treated with cerclage wiring after removal of the stem. Radiographic and clinical results of these 20 patients were compared with the remaining 100 implants in which this complication did not occur. In 20% of the cases of both groups, a migration of less than 2 mm was observed. No differences were detected in Harris Hip Scores, subsidence of the stem, and radiographic behavior. We concluded that a properly stabilized proximal femoral fracture above the lesser trochanter did not influence the clinical and radiographic results at more than 3 years follow-up.

  16. The biomechanical effect of bone quality and fracture topography on locking plate fixation in periprosthetic femoral fractures.

    PubMed

    Leonidou, Andreas; Moazen, Mehran; Lepetsos, Panagiotis; Graham, Simon M; Macheras, George A; Tsiridis, Eleftherios

    2015-02-01

    Optimal management of periprosthetic femoral fractures (PFF) around a well fixed prosthesis (Vancouver B1) remains controversial as adequate fixation needs to be achieved without compromising the stability of the prosthesis. The aim of this study was to highlight the effect of bone quality i.e. canal thickness ratio (CTR), and fracture topography i.e. fracture angle and its position in relation to the stem, on the biomechanics of a locking plate for a Vancouver B1 fracture. A previously corroborated simplified finite element model of a femur with a cemented total hip replacement stem was used in this study. Canal thickness ratio (CTR) and fracture topography were altered in several models and the effect of these variations on the von Mises stress on the locking plate as well as the fracture displacement was studied. Increasing the CTR led to reduction of the von Mises stress on the locking plate as well as the fracture movement. In respect to the fracture angle with the medial cortex, it was shown that acute angles resulted in lower von Mises stress on the plate as opposed to obtuse angles. Furthermore, acute fracture angles resulted in lower fracture displacement compared to the other fractures considered here. Fractures around the tip of the stem had the same biomechanical effect on the locking plate. However, fractures more distal to the stem led to subsequent increase of stress, strain, and fracture displacement. Results highlight that in good bone quality and acute fracture angles, single locking plate fixation is perhaps an appropriate management method. On the contrary, for poor bone quality and obtuse fracture angles alternative management methods might be required as the fixation might be under higher risk of failure. Clinical studies for the management of PFF are required to further support our findings.

  17. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-04-15

    The objective of this project is to develop an improved ultra-lightweight cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary of Halliburton Energy Services (HES) and BJ Services historical performance data for lightweight cement applications. These data are analyzed and compared to ULHS cement and foamed cement performances. Similar data is expected from Schlumberger, and an analysis of this data will be completed in the following phases of the project. Quality control testing of materials used to formulate ULHS cements in the laboratory was completed to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS and foamed cement. This protocol is presented and discussed. Results of further testing of ULHS cements are presented along with an analysis to establish cement performance design criteria to be used during the remainder of the project. Finally, a list of relevant literature on lightweight cement performance is compiled for review during the next quarter.

  18. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-04-29

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, comparison studies of the three cement systems examined several properties: tensile strength, Young's modulus, and shear bond. Testing to determine the effect of temperature cycling on the shear bond properties of the cement systems was also conducted. In addition, the stress-strain behavior of the cement types was studied. This report discusses a software program that is being developed to help design ULHS cements and foamed cements.

  19. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-10-31

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, a comparison study of the three cement systems examined the effect that cement drillout has on the three cement systems. Testing to determine the effect of pressure cycling on the shear bond properties of the cement systems was also conducted. This report discusses testing that will be performed for analyzing the alkali-silica reactivity of ULHS in cement slurries, as well as the results of Field Tests 1 and 2.

  20. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-07-18

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job.

  1. Mycotic femoral aneurysm.

    PubMed

    Wilson, Richard Scott; Bennett, Kenneth R

    2007-05-01

    After several weeks of fever and chills, a 31-year-old logger developed pain in his right thigh. Upon examination a tender, pulsating upper thigh mass was found with a long loud bruit arising from it. Severe aortic insufficiency was present; however, blood cultures were negative. An angiogram, captured blood with contrast spewing from the profunda femoral artery to fill a 5 x 10 cm sac. A false aneurysm was diagnosed and resected; numerous gram positive cocci were present in cut sections, but cultures from the cavity grew the gram negative bacteria Salmonella and Alcaligenes. After one month of intravenous ampicillin the aortic valve was replaced after being destroyed by endocarditis. Ampicillin was continued and recovery was uneventful. Mycotic aneurysms are commonly caused by Salmonella (10%), which was second only to Staphylococcus (30%). The femoral artery accounts for 38% of all mycotic aneurysms. They typically present with a pulsatile mass (52%), bruit (50%), and fever (48%). This diagnosis can be supported by leukocytosis (64-71%), positive blood cultures (50-85%), and a history of arterial trauma (51%) (injection drug use, intravascular procedure, or trauma) or endocarditis (10%).

  2. A new technique for cement augmentation of the sliding hip screw in proximal femur fractures.

    PubMed

    Stoffel, Karl K; Leys, Toby; Damen, Nikki; Nicholls, Rochelle L; Kuster, Markus S

    2008-01-01

    Fractures of the osteoporotic proximal femur are a significant source of mortality and morbidity in today's ageing population. Even with modern fixation techniques such as the sliding hip screw, a certain percentage of fixations will fail due to cut-out of the screw. This study presents a new method for augmenting hip screws with cement to reinforce the fixation. Unstable pertrochanteric fractures were created in paired osteoporotic cadaver femora (n=10). The fractures were fixed using either standard fixation techniques (dynamic hip screw), or using a dynamic hip screw augmented with cement. Cement was introduced using a customised jig to guide cement into a region superior to the screw in the femoral head. Cut-out resistance was assessed using a biaxial material testing machine, with loading applied in compression until failure. The new cement augmentation technique significantly improved the cut-out strength of the fixation (mean 42%; P=0.032). The failure mechanism for both groups was the same, with failure occurring through compression of the cancellous bone superior to the screw. The mean increase in temperature at the femoral neck was 3.7 degrees C in augmented bones, which is much lower than values previously reported for polymethylmethacrylate cements. Several benefits with this technique have emerged. The method is technically straightforward. The risk of cement penetration into the joint is reduced, and cement is targetted to the areas of the femoral head where it is most needed. The exothermic reaction is minimised by reducing the volume of cement used. The first clinical results are promising.

  3. Primary total hip arthroplasty with hydroxyapatite coated titanium femoral stems. Does design philosophy influence long term outcome?: Results of a prospective randomised controlled trial with follow-up of 10-15 years.

    PubMed

    Sandiford, N A; Skinner, J A; East, D J; Butler-Manuel, A; Hinves, B L; Shepperd, J A N

    2014-09-01

    We present results of a prospective randomised controlled trial examining two cohorts of patients treated with proximally (Group A) and fully coated (Group B) femoral components with long term follow up. Patients were reviewed preoperatively and 6, 12, 26 and 52 weeks post operatively then annually. The Merle d'Aubigne Postel (MDP) hip score was used to assess clinical outcome. A Visual Analog Score (VAS) was also recorded. Statistical calculation was performed using the student's t- test and Kaplan Meier survival analysis. One hundred and four patients were included in group A and 103 patients in group B. Mean age was 60.4 years and 60.8 years respectively. Mean follow- up was 12.9 years. Mean pre-operative MDP scores were 8.8 and 9.5 in Groups A and B respectively. Mean pre-operative VAS score 7.8 and 7.4 respectively. At final follow up mean MDP and VAS were 16.9, 16.6 and 2.1, 2.4 respectively. Three femoral revisions occurred in Group A. Seven revisions occurred in Group B. Survival of the femoral component with revision for any reason as the end point was 96% in Group A and 94.8% in Group B. Both components produced symptomatic relief and similar revision rates. Thigh pain occurred only in Group A.

  4. Management and outcome of interprosthetic femoral fractures.

    PubMed

    Platzer, Patrick; Schuster, Rupert; Luxl, Monika; Widhalm, Harald Kurt; Eipeldauer, Stefan; Krusche-Mandl, Irena; Ostermann, Roman; Blutsch, Beate; Vécsei, Vilmos

    2011-11-01

    Interprosthetic femoral fractures following ipsilateral hip and knee arthroplasty are a rare but serious complication in clinical practice. In most cases, adequate management of these injuries might constitute a challenging problem. However, the literature provides only few data regarding the treatment and outcome of interprosthetic femoral fractures, and there are only few classifications available, which might assist in finding an appropriate treatment concept. The purpose of this study was to analyse our experience in the management of interprosthetic femoral fractures following ipsilateral hip and knee joint replacement. We reviewed the clinical and radiographic records of 23 patients (15 female and eight male, average age: 79.2 years) with an interprosthetic fracture after ipsilateral hip and knee joint replacement between 1992 and 2008. For the classification of interprosthetic femoral fractures, the fractures were divided into three types, depending on the fracture site and the adjacency to the prostheses. All patients underwent operative stabilisation, either by lateral plate fixation (n=19), by revision arthroplasty using a long stem (n=2) or by plate fixation and revision arthroplasty (n=2). Referring to the clinical outcome, 16 patients returned to their pre-injury activity level and were satisfied with their clinical outcome. In six patients, we saw a relevant decrease of hip or knee function and severe limitations in gait and activities of daily living. We had a mean Harris Hip Score (HHS) of 78.4 points, and a mean Knee injury and Osteoarthritis Outcome Score (KOOS) of 71.8 points. Relating to the radiographic outcome, successful fracture healing was achieved in 19 of 22 patients (86%) within 6 months. Failures of reduction and fixation were noted in four (18%) of 22 patients. We had a satisfactory outcome following individualised treatment of interprosthetic femoral fractures following ipsilateral hip and knee joint replacement. Compared to the rare

  5. Treatment of Femoral Neck Fracture with a Minimal Invasive Surgical Approach for Hemiarthroplasty – Clinical and Radiological Results in 180 Geriatric Patients

    PubMed Central

    Unger, A.C; Dirksen, B; Renken, F. G; Wilde, E; Willkomm, M; Schulz, A.P

    2014-01-01

    Purpose : The Direct Anterior Approach (DAA) is well established as a minimal access approach in elective orthopaedic hip surgery. For the growing number of elderly patients with femoral neck fractures treated with Bipolar Hip Hemiarthroplasty (BHH), only a few results do exist. The study shows the clinical and radiological outcome for 180 patients treated by a modified DAA with BHH. Materials and Methods : The data of 180 geriatric patients with medial femoral neck fractures were evaluated retrospectively. The general and surgical complications, mobilisation using the Timed Up and Go test (TUG), the social environment pre- and postoperative and the radiological results have been compared with established approaches for geriatric hip surgery. Results : After joint replacement, 18 (10%) patients were developed pneumonia, of which 3 (1.7%) died during hospitalisation. In 7 cases (4%), surgical revision had to be carried out: three times (1.7%) because of a seroma, three times (1.7%) because of subcutaneous infection, and one time (0.6%) because the BHH was removed, owing to deep wound infection. One dislocation (0.6%) occurred, as well as one femoral nerve lesion (0.6%) occured. 88.3% of patients were mobilised on walkers or crutches; the Timed Up and Go Test showed a significant improvement during inpatient rehabilitation. 83% were discharged to their usual social environment, 10% were transferred to a short-term care facility and 7% were relocated permanently to a nursing home. 3/4 of patients had a cemented stem alignment in the range between -5° and 5°, while 2/3 of patients had a maximum difference of 1 cm in leg length. Conclusion : Using the modified DAA, a high patient satisfaction is achieved after implantation of a BHH. The rate of major complications is just as low as in conventional approaches, and rapid mobilisation is possible. PMID:25136389

  6. Cementing constrained acetabular liners in revision hip replacement: clinical and laboratory observations.

    PubMed

    Mountney, John; Garbuz, Donald S; Greidanus, Nelson V; Masri, Bassam A; Duncan, Clive P

    2004-01-01

    During revision hip arthroplasty, removal of a well-fixed, ingrown metal acetabular component may not be possible. Therefore, a new polyethylene liner can be cemented into the existing shell via the cement locking mechanism. This technique is well recognized, and the cement locking mechanism has proved to be sufficiently strong and durable for clinical use. A constrained polyethylene liner is designed to reduce the risk of hip dislocation by capturing the femoral head. However, there are increased shear forces created at the liner interface as the dislocation is resisted. If a constrained liner is cemented into an ingrown acetabular component, then there is the theoretical risk that these increased shear forces will damage the cement locking mechanism, thus leading to failure of the construct. There are a few clinical series in which a constrained liner has been used with the cement locking mechanism. Overall, the failure rate of the cement locking mechanism is no greater if a constrained liner instead of a standard liner is used. The cement locking mechanism can be strengthened by roughening the backside of a smooth polyethylene liner to improve the cement-polyethylene interface, or by using an all-polyethylene acetabular component that is designed to be used with cement. Whether a smooth metal shell needs to be roughened as well is a matter of debate.

  7. Cemented total hip prosthesis: Radiographic and scintigraphic evaluation

    SciTech Connect

    Aliabadi, P.; Tumeh, S.S.; Weissman, B.N.; McNeil, B.J. )

    1989-10-01

    Conventional radiographs, technetium-99m bone scans, and gallium-67 scans were reviewed in 44 patients who had undergone cemented total hip joint replacement and were imaged because of suspicion of prosthesis loosening or infection. A complete radiolucent line of 2 mm or wider along the bone-cement interface or metal-cement lucency on conventional radiographs was used as the criterion for prosthetic loosening with or without infection and proved to be 54% sensitive and 96% specific. Scintigraphic criteria for prosthetic loosening were increased focal uptake of the radiopharmaceutical for the femoral component and increased focal or diffuse uptake for the acetabular component. For bone scintigraphy, sensitivity was 73% and specificity was 96%. Combining the results of conventional radiographs and bone scans increased sensitivity to 84% and decreased specificity to 92% for the diagnosis of loosening, infection, or both. The study also showed that Ga-67 scintigraphy has a low sensitivity for the detection of infection.

  8. The management of femoral bone stock in THA revision: indications and techniques.

    PubMed

    Bianchi, Luca; Galante, Claudio; Zagra, Luigi

    2014-10-02

    Following the increasing number of total hip arthroplasties, the amount of hip revision procedures continue to rise. Careful patient selection and bone loss evaluation is crucial for a correct management of femoral revision procedures. The key point in femoral revision is to obtain a reliable primary stability of the stem, with the least invasive implant as possible, to preserve and if possible to restore the bone stock. In this article we present the indications and the techniques for the femoral revisions most commonly used in Europe, referring to the evidence in the literature and our personal experiences.

  9. Improvement of casing cementation of deep and ultradeep wells. Part 2: Oilfield cements and cement additives

    NASA Astrophysics Data System (ADS)

    Arens, K. H.; Akstinat, M.

    1982-07-01

    Oilfield cements and cement additives were investigated in order to improve the casing cementation of deep and ultradeep wells. Characterization and evaluation of the main oil field cements commercially available were studied. The testing was carried out according to American Petroleum Institute API standards and nonstandardized test methods (dynamic modulus of elasticity, expansion/shrinkage), especially the rheology, thickening time and the influence of pressure, temperature and water-cement ratio, were considered. The main emphasis in the field of cement additives was on the evaluation of cement retarders for high temperatures, accelerators, and additives for cement expansion. Furthermore oil field cements were tested, and their properties are described.

  10. Abyssal seep site cementation

    SciTech Connect

    Neumann, A.C.; Paull, C.K.; Commeau, R.; Commeau, J.

    1988-01-01

    The deepest submarine cements known so far occur along the 3,300-m deep base of the Florida escarpment and are associated with methane-bearing brine seeps, which emanate there. These deep Holocene carbonates, which occur as surficial and buried crusts, burrow fillings, and friable horizons, were sampled via ALVIN. The carbonates form irregular halos extending up to 20 m from seeps colonized by chemosynthetic fauna. Mussels, gastropods, and clams, the carbonate components of the community, produce a shell hash that is locally cemented by coarsely crystalline low-Mg calcite. Halos of palisade calcite are reminiscent of ancient examples of marine cements. Also present are carbonate hemipelagics cemented by micrite into crusts and burrow fillings. The degree of cementation varies from pervasive to light. Slabs of cemented crust up to 30 cm thick contrast with typical shallow crusts and exhibit irregular tops and smooth bottoms indicating different chemical gradients and pathways.

  11. Cementation of indirect restorations: an overview of resin cements.

    PubMed

    Stamatacos, Catherine; Simon, James F

    2013-01-01

    The process of ensuring proper retention, marginal seal, and durability of indirect restorations depends heavily on effective cementation. Careful consideration must be made when selecting an adhesive cement for a given application. This article provides information on resin cements that can guide clinicians in determining which type of cement is best suited to their clinical needs regarding cementation of indirect restorations. Emphasis is placed on successful cementation of all-ceramic restorations.

  12. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-01-31

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries. DOE joined the Materials Management Service (MMS)-sponsored joint industry project ''Long-Term Integrity of Deepwater Cement under Stress/Compaction Conditions.'' Results of the project contained in two progress reports are also presented in this report.

  13. Femoral offset following trochanteric femoral fractures: a prospective observational study.

    PubMed

    Buecking, Benjamin; Boese, Christoph Kolja; Seifert, Vinzenz; Ruchholtz, Steffen; Frink, Michael; Lechler, Philipp

    2015-10-01

    Reconstruction of the femoral offset reportedly improves outcome following total hip arthroplasty, but little is known of its influence following hip fractures. We aimed to establish the effect of the femoral offset on the medium-term functional outcome in elderly patients who had sustained trochanteric fractures requiring proximal femoral nailing. We measured the rotation corrected femoral offset (FORC) and relative femoral offset (FORL) on plain anteroposterior radiographs of the hip in 188 patients (58 male, 130 female) with a trochanteric fracture who underwent proximal femoral nailing at our institution. The primary outcome measure was the Harris hip score (HSS) 6 and 12 months postoperatively; the Barthel index was assessed as a secondary outcome. The mean FORC after surgery was 58 mm (±11 mm), while the mean FORL was 1.21 (±0.22). At final follow up, we found significant inverse relationships (Spearman's rank correlation coefficient, ρ) between FORC and FORL and the functional outcome assessed by the HSS (FORC: ρ = -0.207, p = 0.036; FORL: ρ = -0.247, p = 0.012), and FORL and the Barthel index (FORC: ρ = -147, p = 0.129; FORL: ρ = -0.192, p = 0.046). A consistent trend was observed after adjustment for confounding variables. Our results underline the biomechanical importance of the femoral offset for medium-term outcomes in elderly patients with trochanteric fractures. In contrast with the published findings on total hip arthroplasty, we found an inverse correlation between functional outcome and the extent of the reconstructed femoral offset. Level I - Prognostic study. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. 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.

  15. Comparative analysis of the biological effects of the endodontic bioactive cements MTA Angelus, MTA Repair HP and NeoMTA Plus on human dental pulp stem cells.

    PubMed

    Tomás-Catalá, C J; Collado-González, M; García-Bernal, D; Oñate-Sánchez, R E; Forner, L; Llena, C; Lozano, A; Castelo-Baz, P; Moraleda, J M; Rodríguez-Lozano, F J

    2017-09-11

    To evaluate the biological effects in vitro of MTA Angelus (MTA-Ang; Angelus, Londrina, PR, Brazil), MTA Repair HP (MTA-HP; Angelus,) and NeoMTA Plus (NeoMTA-P; Avalon Biomed Inc, Bradenton, FL, USA) on human dental pulp stem cells (hDPSCs). Cell viability and cell migration assays were performed using eluates of each material. To evaluate cell morphology and cell attachment to the different materials, hDPSCs were directly seeded onto the material surfaces and analyzed by immunocytofluorescence and scanning electron microscopy, respectively. The chemical composition of the materials was determined by energy dispersive X-ray (EDX) and eluates were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α <0.05). Undiluted MTA-Ang, MTA-HP and NeoMTA-P displayed a significant increase in cell viability greater than that obtained using complete medium alone (control) (*p<0.05; **p<0.01; ***p<0.001). Moreover, a cell migration assay revealed cell migration rates after incubation with extracts of MTA-Ang, MTA-HP and NeoMTA-P, that were similar to levels obtained in the control group. In addition, stretched cytoskeletal F-actin fibres were detected in the cells treated with the three material extracts. SEM studies revealed a high degree of cell proliferation and attachment on all three materials. EDX analysis demonstrated similar weight percentages of C, O and Ca in all three materials, while other elements such as Al, Si and S were also found. MTA-Ang, MTA-HP, and NeoMTA-P were associated with biological effects on hDPSCs in terms of cell proliferation, morphology, migration and attachment. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  16. A New Biphasic Dicalcium Silicate Bone Cement Implant.

    PubMed

    Zuleta, Fausto; Murciano, Angel; Gehrke, Sergio A; Maté-Sánchez de Val, José E; Calvo-Guirado, José L; De Aza, Piedad N

    2017-07-06

    This study aimed to investigate the processing parameters and biocompatibility of a novel biphasic dicalcium silicate (C₂S) cement. Biphasic α´L + β-C₂Sss was synthesized by solid-state processing, and was used as a raw material to prepare the cement. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid (SBF) and human adipose stem cell cultures. Two critical-sized defects of 6 mm Ø were created in 15 NZ tibias. A porous cement made of the high temperature forms of C₂S, with a low phosphorous substitution level, was produced. An apatite-like layer covered the cement's surface after soaking in SBF. The cell attachment test showed that α´L + β-C₂Sss supported cells sticking and spreading after 24 h of culture. The cement paste (55.86 ± 0.23) obtained higher bone-to-implant contact (BIC) percentage values (better quality, closer contact) in the histomorphometric analysis, and defect closure was significant compared to the control group (plastic). The residual material volume of the porous cement was 35.42 ± 2.08% of the initial value. The highest BIC and bone formation percentages were obtained on day 60. These results suggest that the cement paste is advantageous for initial bone regeneration.

  17. Palacos compared to Palamed bone cement in total hip replacement: a randomized controlled trial

    PubMed Central

    Meinardi, Joris E; Valstar, Edward R; Van Der Voort, Paul; Kaptein, Bart L; Fiocco, Marta; Nelissen, Rob G H H

    2016-01-01

    Background and purpose Stability and survival of cemented total hip prostheses is dependent on a multitude of factors, including the type of cement that is used. Bone cements vary in viscosity, from low to medium and high. There have been few clinical RSA studies comparing the performance of low- and high-viscosity bone cements. We compared the migration behavior of the Stanmore hip stem cemented using novel low-viscosity Palamed bone cement with that of the same stem cemented with conventional high-viscosity Palacos bone cement. Patients and methods We performed a randomized controlled study involving 39 patients (40 hips) undergoing primary total hip replacement for primary or secondary osteoarthritis. 22 patients (22 hips) were randomized to Palacos and 17 patients (18 hips) were randomized to Palamed. Migration was determined by RSA. Results None of these 40 hips had been revised at the 10-year follow-up mark. To our knowledge, the patients who died before they reached the 10-year endpoint still had the implant in situ. No statistically significant or clinically significant differences were found between the 2 groups for mean translations, rotations, and maximum total-point motion (MTPM). Interpretation We found similar migration of the Stanmore stem in the high-viscosity Palacos cement group and the low-viscosity Palamed cement group. We therefore expect that the risk of aseptic loosening with the new Palamed cement would be comparable to that with the conventional Palacos cement. The choice of which type of bone cement to use is therefore up to the surgeon’s preference. PMID:27329869

  18. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2004-01-30

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries.

  19. Mechanical testing and osteointegration of titanium implant with calcium phosphate bone cement and autograft alternatives.

    PubMed

    Lin, Dan-Jae; Ju, Chien-Ping; Huang, Shu-Huei; Tien, Yin-Chun; Yin, Hsiang-Shu; Chen, Wen-Cheng; Chern Lin, Jiin-Huey

    2011-10-01

    The purpose of this study was to evaluate the osteointegration of a titanium (Ti) implant with the calcium phosphate cement (CPC) and autograft prostheses by pull-out test and histological examination. Stems of sixty Ti cylinders were bilaterally inserted into femoral medullary canals in 30 rabbits at the 1st, 4th, 12th, 26th and 70th postoperative weeks. The bone autograft and CPC were filled into the pre-trimmed bone marrow cavity with a polymethyl methacrylate retarder in the distal end, and then a Ti cylinder was inserted into femurs. The CPC group was significantly (p<0.05) associated with a larger pull-out force at 4th (37%) and 12th (62%) weeks compared to the autograft group. The bone area and the bone-to-implant contact ratios of the CPC groups were significantly higher than that of the autograft groups at early healing stage. The histological exams suggest that the CPC enhanced the earlier bone formation around the implant at a period not longer than 12 weeks postoperation. We conclude that CPC graft has the higher ability to facilitate the osteointegration and stabilize the Ti implant at a relatively early stage than the autograft in vivo. Copyright © 2011. Published by Elsevier Ltd.

  20. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-01-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems: foamed and sodium silicate slurries. Comparison studies of the three cement systems examined several properties: tensile strength, Young's modulus, water permeability, and shear bond. Testing was also done to determine the effect that temperature cycling has on the shear bond properties of the cement systems. In addition, analysis was carried out to examine alkali silica reactivity of slurries containing ULHS. Data is also presented from a study investigating the effects of mixing and pump circulation on breakage of ULHS. Information is also presented about the field application of ULHS in cementing a 7-in. intermediate casing in south Texas.

  1. Implant survival of the most common cemented total hip devices from the Nordic Arthroplasty Register Association database

    PubMed Central

    Junnila, Mika; Laaksonen, Inari; Eskelinen, Antti; Pulkkinen, Pekka; Ivar Havelin, Leif; Furnes, Ove; Marie Fenstad, Anne; Pedersen, Alma B; Overgaard, Søren; Kärrholm, Johan; Garellick, Göran; Malchau, Henrik; Mäkelä, Keijo T

    2016-01-01

    Background and purpose According to previous Nordic Arthroplasty Register Association (NARA) data, the 10-year implant survival of cemented total hip arthroplasties (THAs) is 94% in patients aged 65–74 and 96% in patients aged 75 or more. Here we report a brand-level comparison of cemented THA based on the NARA database, which has not been done previously. Patients and methods We determined the rate of implant survival of the 9 most common cemented THAs in the NARA database. We used Kaplan-Meier analysis with 95% CI to study implant survival at 10 and 15 years, and Cox multiple regression to assess survival and hazard ratios (HRs), with revision for any reason as endpoint and with adjustment for age, sex, diagnosis, and femoral head material. Results Spectron EF THA (89.9% (CI: 89.3–90.5)) and Elite THA (89.8% (CI: 89.0–90.6)) had the lowest 10-year survivorship. Lubinus (95.7% survival, CI: 95.5–95.9), MS 30 (96.6%, CI: 95.8–97.4), and C-stem THA (95.8%, CI: 94.8–96.8) had a 10-year survivorship of at least 95%. Lubinus (revision risk (RR) = 0.77, CI: 0.73–0.81), Müller (RR =0.83, CI: 0.70–0.99), MS-30 (RR =0.73, CI: 0.63–0.86), C-stem (RR =0.70, CI: 0.55–0.90), and Exeter Duration THA (RR =0.84, CI: 0.77–0.90) had a lower risk of revision than Charnley THA, the reference implant. Interpretation The Spectron EF THA and the Elite THA had a lower implant survival than the Charnley, Exeter, and Lubinus THAs. Implant survival of the Müller, MS 30, CPT, and C-stem THAs was above the acceptable limit for 10-year survival. PMID:27550058

  2. Fixation techniques and stem dimensions in hinged total knee arthroplasty: a finite element study.

    PubMed

    El-Zayat, Bilal Farouk; Heyse, Thomas J; Fanciullacci, Nelson; Labey, Luc; Fuchs-Winkelmann, Susanne; Innocenti, Bernardo

    2016-12-01

    No evidence-based guidelines are available to determine the appropriate stem length, and whether or not to cement stems in revision total knee arthroplasty (TKA). Therefore, the objective of this study was to compare stresses and relative movement of cemented and uncemented stems of different lengths using a finite element analysis. A finite element model was created for a synthetic tibia. Two stem lengths (95 and 160 mm) and two types of fixation (cemented or press fit) of a hinged TKA were examined. The average compressive stress distribution in different regions of interest, as well as implant micromotions, was determined and compared during lunge and squat motor tasks. Both long and short stems in revision TKA lead to high stresses, primarily in the region around the stem tip. The presence of cement reduces the stresses in the bone in every region along the stem. Short stem configurations are less affected by the presence of cement than the long stem configuration. Press-fit stems showed higher micromotions compared to cemented stems. Lowest stresses and micromotion were found for long cemented stems. Cementless stems showed more micromotion and increased stress levels especially at the level of the stem tip, which may explain the clinical phenomenon of stem-end pain following revision knee arthroplasty. These findings will help the surgeon with optimal individual implant choice.

  3. Comparison of cementless and hybrid cemented total knee arthroplasty.

    PubMed

    Lass, Richard; Kubista, Bernd; Holinka, Johannes; Pfeiffer, Martin; Schuller, Spiro; Stenicka, Sandra; Windhager, Reinhard; Giurea, Alexander

    2013-04-01

    Cementless total knee arthroplasty (TKA) implants were designed to provide long-term fixation without the risk of cement-associated complications. The purpose of this study was to evaluate the outcome of titanium-coated cementless implants compared with hybrid TKA implants with a cemented tibial and a cementless femoral component. The authors performed a case-control, single-center study of 120 TKAs performed between 2003 and 2007, including 60 cementless and 60 hybrid cemented TKAs. The authors prospectively analyzed the radiographic and clinical data and the survivorship of the implants at a minimum follow-up of 5 years. Ninety patients who underwent TKA completed the 5-year assessment. Knee Society Scores increased significantly in both groups (P<.001). In both groups, 2 patients underwent revision due to aseptic tibial component loosening, resulting in a 96% implant survival rate. Radiographs showed significantly less radiolucent lines around the tibial baseplate in the cementless group (n=12) than in the hybrid cemented group (n=26) (P=.009).At 6-year mean follow-up, no significant difference existed between the cementless and hybrid cemented tibial components in TKA in terms of clinical and functional results and postoperative complications. The significantly smaller number of radiolucent lines in the cementless group is an indicator of primary stability with the benefit of long-term fixation durability of TKA.

  4. A Complication During Femoral Broaching in Total Hip Arthroplasty: A Case Report

    PubMed Central

    Waldstein, Wenzel; Boettner, Friedrich

    2013-01-01

    Press-fit component fixation is one of the primary goals in uncemented total hip arthroplasty. When aiming at proximal load transfer, the stem size has to be selected with regard to the shape of the proximal femoral canal. This can be challenging in patients with ‘champagne flute’ femurs with a relatively narrow diaphysis, especially when a long stem femoral component is used. The present case report describes a complication during femoral broaching for a primary uncemented femoral component. Because of the narrow diaphysis, the distal portion of the broach got caught in the narrow canal and it became impossible to remove the broach with conventional techniques. Via a second distal incision, the femur was split from the distal tip of the broach to approximately 5 cm distal of the femoral neck cut along the posterior aspects of the femur. This loosened the broach enough to allow for an uncomplicated removal. The longitudinal split was secured with cables before a similar size primary implant was press fitted into the femoral canal. PMID:23961301

  5. Timing of syntaxial cement

    SciTech Connect

    Perkins, R.D.

    1985-02-01

    Echinodermal fragments are commonly overgrown in ancient limestones, with large single crystals growing in optical continuity over their skeletal hosts (i.e., syntaxial overgrowths). Such syntaxial cements are usually considered to have precipitated from meteoric pore waters associated with a later stage of subaerial exposure. Although several examples have been reported from ancient carbonates where petrographic relationships may indicate an early submarine formation of syntaxial cement, no occurrences have been noted in Holocene submarine-cemented rocks. Syntaxial cements of submarine origin have been found in Bermuda beachrock where isopachous high-magnesian calcite cements merge with large optically continuous crystals growing on echinodermal debris. Examination of other Holocene sediments cemented by magnesian calcite indicates that echinodermal fragments are not always overgrown syntaxially, but may be rimmed by microcrystalline calcite. The reason for this difference is not clear, although it may be a function of the spacing of nucleation sites and rates of crystal growth. A review of syntaxial cements from several localities in ancient carbonate sequences reveals that many are best interpreted as having formed in the submarine setting, whereas it is more clear that others formed from meteoric precipitation. These occurrences suggest that care should be exercised in inferring meteoric diagenesis from syntaxial overgrowths and that the possibility of submarine formation should be considered.

  6. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-07-31

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries. Laboratory testing during the eleventh quarter focused on evaluation of the alkali-silica reaction of eight different cement compositions, four of which contain ULHS. This report provides a progress summary of ASR testing. The original laboratory procedure for measuring set cement expansion resulted in unacceptable erosion of the test specimens. In subsequent tests, a different expansion procedure was implemented and an alternate curing method for cements formulated with TXI Lightweight cement was employed to prevent sample failure caused by thermal shock. The results obtained with the modified procedure showed improvement over data obtained with the original procedure, but data for some compositions were still questionable. Additional modification of test procedures for compositions containing TXI Lightweight cement were implemented and testing is ongoing.

  7. An Experimental Study to Determine the Role of Inferior Vena Cava Filter in Preventing Bone Cement Implantation Syndrome

    PubMed Central

    Guo, Wangang; Zheng, Qiangsun; Li, Bingling; Shi, Xiaoqin; Xiang, Dingcheng; Wang, Chen

    2015-01-01

    Background: Inferior vena cava filters (IVCF) are frequently used for preventing pulmonary embolism (PE) following deep venous thromboembolism. Objectives: The present study was designed to investigate whether IVCF could prevent or impede the occurrence of bone cement implantation syndrome (BCIS), since PE is considered as the central mechanism of BCIS. Materials and Methods: Fifteen sheep were divided into three groups: bone cement free (BCF) group, cement implantation (CI) group and IVCF group. In all the groups, an osteotomy proximal to the greater trochanter of left femur was carried out. In BCF group, the femoral canal was not reamed out or packed with any bone cement. In CI and IVCF groups, the left femoral canals were packed with bone cement, to simulate the cementing procedures carried out in hip replacement. An OptEase® filter was placed and released in inferior vena cava, prior to packing cement in the femoral canal in IVCF group, while the IVCF was not released in the CI group. The BCF group was considered as control. Results: Systolic blood pressure (SBP), saturation of oxygen (SaO2) and partial pressure of carbon dioxide (PaCO2) declined significantly 10 min after the bone cement packing, in CI group, compared to those in BCF group. This was accompanied by a rise in the arterial pH. However, IVCF prevented those changes in the CI group. On ultrasonography, there were dotted echoes in right atrium in the CI group, after bone cement packing, while such echoes were hardly seen in the IVCF group. Conclusion: This study demonstrates that IVCF could prevent BCIS effectively, and, as a corollary, suggests that PE represents the leading cause of the constellation of BCIS symptoms. PMID:26557267

  8. Cement and concrete

    NASA Technical Reports Server (NTRS)

    Corley, Gene; Haskin, Larry A.

    1992-01-01

    To produce lunar cement, high-temperature processing will be required. It may be possible to make calcium-rich silicate and aluminate for cement by solar heating of lunar pyroxene and feldspar, or chemical treatment may be required to enrich the calcium and aluminum in lunar soil. The effects of magnesium and ferrous iron present in the starting materials and products would need to be evaluated. So would the problems of grinding to produce cement, mixing, forming in vacuo and low gravity, and minimizing water loss.

  9. Stage cementing apparatus

    SciTech Connect

    Blamford, D.M.; Easter, J.H.

    1988-06-21

    A stage cementing apparatus for selectively passing cement from the interior passage of a casing to the annulus between the exterior of the casing and borehole, the casing having an upper portion and a lower portion, is described comprising: a barrel secured to the upper portion of the casing; a mandrel secured to the lower portion of the casing, and a stage cementing tool having a generally cylindrical configuration adapted for attachment to the lower end of the barrel about a portion of the mandrel.

  10. Sedentary lifestyle related exosomal release of Hotair from gluteal-femoral fat promotes intestinal cell proliferation

    PubMed Central

    Lu, Xiaozhao; Bai, Danna; Liu, Xiangwei; Zhou, Chen; Yang, Guodong

    2017-01-01

    Pioneering epidemiological work has established strong association of sedentary lifestyle and obesity with the risk of colorectal cancer, while the detailed underlying mechanism remains unknown. Here we show that Hotair (HOX transcript antisense RNA) is a pro-adipogenic long non-coding RNA highly expressed in gluteal-femoral fat over other fat depots. Hotair knockout in adipose tissue results in gluteal-femoral fat defect. Squeeze of the gluteal-femoral fat induces intestinal proliferation in wildtype mice, while not in Hotair knockout mice. Mechanistically, squeeze of the gluteal-femoral fat induces exosomal Hotair secretion mainly by transcriptional upregulation of Hotair via NFκB. And increased exosomal Hotair in turn circulates in the blood and is partially endocytosed by the intestine, finally promoting the stemness and proliferation of intestinal stem/progenitor cells via Wnt activation. Clinically, obese subjects with sedentary lifestyle have much higher exosomal HOTAIR expression in the serum. These findings establish that sedentary lifestyle promotes exosomal Hotair release from the gluteal-femoral fat, which in turn facilitates intestinal stem and/or progenitor proliferation, raising a possible link between sedentary lifestyle with colorectal tumorigenesis. PMID:28361920

  11. Structure, properties and animal study of a calcium phosphate/calcium sulfate composite cement.

    PubMed

    Chen, Wei-Luen; Chen, Chang-Keng; Lee, Jing-Wei; Lee, Yu-Ling; Ju, Chien-Ping; Lin, Jiin-Huey Chern

    2014-04-01

    In-vitro and in-vivo studies have been conducted on an in-house-developed tetracalcium phosphate (TTCP)/dicalcium phosphate anhydrous (DCPA)/calcium sulfate hemihydrate (CSH)-derived composite cement. Unlike most commercial calcium-based cement pastes, the investigated cement paste can be directly injected into water and harden without dispersion. The viability value of cells incubated with a conditioned medium of cement extraction is >90% that of Al2O3 control and >80% that of blank medium. Histological examination reveals excellent bonding between host bone and cement without interposition of fibrous tissues. At 12 weeks-post implantation, significant remodeling activities are found and a new bone network is developed within the femoral defect. The 26-week samples show that the newly formed bone becomes more mature, while the interface between residual cement and the new bone appears less identifiable. Image analysis indicates that the resorption rate of the present cement is much higher than that of TTCP or TTCP/DCPA-derived cement under similar implantation conditions. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  12. The long-term in vivo behavior of polymethyl methacrylate bone cement in total hip arthroplasty

    PubMed Central

    2011-01-01

    Background and purpose The long-term success of cemented total hip arthroplasty (THA) has been well established. Improved outcomes, both radiographically and clinically, have resulted mainly from advances in stem design and improvements in operating techniques. However, there is concern about the durability of bone cement in vivo. We evaluated the physical and chemical properties of CMW1 bone cements retrieved from patients undergoing revision THA. Methods CMW1 cements were retrieved from 14 patients who underwent acetabular revision because of aseptic loosening. The time in vivo before revision was 7–30 years. The bending properties of the retrieved bone cement were assessed using the three-point bending method. The molecular weight and chemical structure were analyzed by gel permeation chromatography and Fourier-transform infrared spectroscopy. The porosity of the bone cements was evaluated by 3-D microcomputer tomography. Results The bending strength decreased with increasing time in vivo and depended on the density of the bone cement, which we assume to be determined by the porosity. There was no correlation between molecular weight and time in vivo. The infrared spectra were similar in the retrieved cements and in the control CMW1 cements. Interpretation Our results indicate that polymer chain scission and significant hydrolysis do not occur in CMW1 cement after implantation in vivo, even in the long term. CMW1 cement was stable through long-term implantation and functional loading. PMID:22103279

  13. A New Biphasic Dicalcium Silicate Bone Cement Implant

    PubMed Central

    Murciano, Angel; Maté-Sánchez de Val, José E.

    2017-01-01

    This study aimed to investigate the processing parameters and biocompatibility of a novel biphasic dicalcium silicate (C2S) cement. Biphasic α´L + β-C2Sss was synthesized by solid-state processing, and was used as a raw material to prepare the cement. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid (SBF) and human adipose stem cell cultures. Two critical-sized defects of 6 mm Ø were created in 15 NZ tibias. A porous cement made of the high temperature forms of C2S, with a low phosphorous substitution level, was produced. An apatite-like layer covered the cement’s surface after soaking in SBF. The cell attachment test showed that α´L + β-C2Sss supported cells sticking and spreading after 24 h of culture. The cement paste (55.86 ± 0.23) obtained higher bone-to-implant contact (BIC) percentage values (better quality, closer contact) in the histomorphometric analysis, and defect closure was significant compared to the control group (plastic). The residual material volume of the porous cement was 35.42 ± 2.08% of the initial value. The highest BIC and bone formation percentages were obtained on day 60. These results suggest that the cement paste is advantageous for initial bone regeneration. PMID:28773119

  14. Femoral Head and Neck Excision.

    PubMed

    Harper, Tisha A M

    2017-07-01

    Femoral head and neck excision is a surgical procedure that is commonly performed in small animal patients. It is a salvage procedure that is done to relieve pain in the coxofemoral joint and restore acceptable function of the limb. Femoral head and neck excision is most commonly used to treat severe osteoarthritis in the coxofemoral joint and can be done in dogs and cats of any size or age. The procedure should not be overused and ideally should not be done when the integrity of the coxofemoral joint can be restored. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Environmentally compatible spray cement

    SciTech Connect

    Loeschnig, P.

    1995-12-31

    Within the framework of a European research project, Heidelberger Zement developed a quickly setting and hardening binder for shotcrete, called Chronolith S, which avoids the application of setting accelerators. Density and strength of the shotcrete produced with this spray cement correspond to those of an unaccelerated shotcrete. An increased hazard for the heading team and for the environment, which may occur when applying setting accelerators, can be excluded here. Owing to the special setting properties of a spray cement, the process engineering for its manufacturing is of great importance. The treatment of a spray cement as a dry concrete with kiln-dried aggregates is possible without any problems. The use of a naturally damp pre-batched mixture is possible with Chronolith S but requires special process engineering; spray cement and damp aggregate are mixed with one another immediately before entering the spraying machinery.

  16. Thermodynamics and cement science

    SciTech Connect

    Damidot, D.; Lothenbach, B.; Herfort, D.; Glasser, F.P.

    2011-07-15

    Thermodynamics applied to cement science has proved to be very valuable. One of the most striking findings has been the extent to which the hydrate phases, with one conspicuous exception, achieve equilibrium. The important exception is the persistence of amorphous C-S-H which is metastable with respect to crystalline calcium silicate hydrates. Nevertheless C-S-H can be included in the scope of calculations. As a consequence, from comparison of calculation and experiment, it appears that kinetics is not necessarily an insuperable barrier to engineering the phase composition of a hydrated Portland cement. Also the sensitivity of the mineralogy of the AFm and AFt phase compositions to the presence of calcite and to temperature has been reported. This knowledge gives a powerful incentive to develop links between the mineralogy and engineering properties of hydrated cement paste and, of course, anticipates improvements in its performance leading to decreasing the environmental impacts of cement production.

  17. 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.

  18. Oxidatively Degradable Poly(thioketal urethane)/Ceramic Composite Bone Cements with Bone-Like Strength.

    PubMed

    McEnery, Madison A P; Lu, Sichang; Gupta, Mukesh K; Zienkiewicz, Katarzyna J; Wenke, Joseph C; Kalpakci, Kerem N; Shimko, Daniel; Duvall, Craig L; Guelcher, Scott A

    2016-01-01

    Synthetic bone cements are commonly used in orthopaedic procedures to aid in bone regeneration following trauma or disease. Polymeric cements like PMMA provide the mechanical strength necessary for orthopaedic applications, but they are not resorbable and do not integrate with host bone. Ceramic cements have a chemical composition similar to that of bone, but their brittle mechanical properties limit their use in weight-bearing applications. In this study, we designed oxidatively degradable, polymeric bone cements with mechanical properties suitable for bone tissue engineering applications. We synthesized a novel thioketal (TK) diol, which was crosslinked with a lysine triisocyanate (LTI) prepolymer to create hydrolytically stable poly(thioketal urethane)s (PTKUR) that degrade in the oxidative environment associated with bone defects. PTKUR films were hydrolytically stable for up to 6 months, but degraded rapidly (<1 week) under simulated oxidative conditions in vitro. When combined with ceramic micro- or nanoparticles, PTKUR cements exhibited working times comparable to calcium phosphate cements and strengths exceeding those of trabecular bone. PTKUR/ceramic composite cements supported appositional bone growth and integrated with host bone near the bone-cement interface at 6 and 12 weeks post-implantation in rabbit femoral condyle plug defects. Histological evidence of osteoclast-mediated resorption of the cements was observed at 6 and 12 weeks. These findings demonstrate that a PTKUR bone cement with bone-like strength can be selectively resorbed by cells involved in bone remodeling, and thus represent an important initial step toward the development of resorbable bone cements for weight-bearing applications.

  19. Fracture of the femoral component after a lightning strike injury: A case report.

    PubMed

    Lizano-Díez, Xavier; Alentorn-Geli, Eduard; León-García, Alfonso; Marqués-López, Fernando

    2017-01-01

    A fracture of the stem in a total hip arthroplasty (THA) is an uncommon complication. We report a case of femoral stem fracture in a 55-year-old male patient after a lightning strike. A revision was conducted using a Wagner osteotomy and a revision prosthesis. Dall-Milles cerclages were used to close the osteotomy. The postoperative evolution was satisfactory, with an immediate partial weight bearing, consolidation of the osteotomy after three months and return to daily activity without pain.

  20. Femoral head cartilage disarticulation disorder

    USDA-ARS?s Scientific Manuscript database

    Femoral head cartilage disarticulation disorder and necrosis is a major skeletal problem in broiler breeders since they are maintained for a long time in the farm. The etiology of this disease is not well understood. A field study was conducted to understand the basis of this metabolic disease. Six ...

  1. Cardiac resynchronization therapy: Femoral approach.

    PubMed

    Brandão, Luís; Miranda, Rita; Almeida, Sofia; Ribeiro, Luciano; Alvarenga, Carlos; João, Isabel; Pereira, Hélder

    2017-04-01

    We describe the case of a 62-year-old female patient with bilateral subclavian vein occlusion, in whom a cardiac resynchronization system was implanted via a femoral vein. Copyright © 2017 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Plate fixation of periprosthetic femur fractures: What happens to the cement mantle?

    PubMed

    Konstantinidis, Lukas; Schmidt, Benjamin; Bernstein, Anke; Hirschmüller, Anja; Schröter, Steffen; Südkamp, Norbert Paul; Helwig, Peter

    2017-02-01

    Osteosynthesis of periprosthetic femur fractures by screw fixation around the implanted prosthetic stem is currently regarded as the biomechanically superior option compared with cerclage. The aim of this biomechanical study was damage analysis of the cement mantle after revision screw insertion. A prosthetic stem (Bicontact) was implanted in 20 cadaveric femora in cemented technique. A locking compression plate (Synthes) was then applied to the lateral femur at the level of the prosthetic stem. The method of plate fixation to the femur was assigned randomly to three groups: bicortical non-locking screws, monocortical locking screws, and bicortical locking screws. This was followed by applying a fluctuating axial load (2100 N, 0.5 Hz) for 20,000 cycles. After testing, macroscopic and microscopic evaluations of the cement mantle were conducted. Cracks formed in the cement mantle in 14% of the 80 screw holes. The type of screw (bicortical or monocortical; locking or non-locking) had no significant effect on the number of cracks (p = 0.52). The relationship between manifestation of crack damage and cement mantle thickness was not significant (p = 0.36), whereas the relationship between crack formation and screw position was significant (p = 0.019). Those screws whose circumference was only partially within the cement mantle yielded a significantly lower number of cracks compared with screws positioned completely within the cement mantle or even touching the prosthetic stem. In order to reduce the incidence of crack formation in the cement mantle during plate osteosynthesis of periprosthetic femur fractures, the screws should not be either placed within the cement mantle or make direct contact with the stem.

  3. HEMIARTHROPLASTY IN THE TREATMENT FRACTURES OF THE FEMORAL NECK

    PubMed Central

    Ono, Nelson Keiske; de Andrade Lima, Guilherme Didier; Honda, Emerson Kiyoshi; Polesello, Giancarlo Cavalli; Guimarães, Rodrigo Pereira; Júnior, Walter Ricioli; de Queiroz, Marcelo Cavalheiro

    2015-01-01

    Objective: To epidemiologically and clinically evaluate patients with displaced femoral neck fractures that were surgically treatment with cemented hip hemiarthroplasty. Methods: All patients with displaced femoral neck fractures (Garden III and IV) who underwent cemented hip hemiarthroplasty using a unipolar prosthesis (Thompson), by means of a posterolateral access between June 2005 and September 2008 were retrospectively evaluated. Results: Seventy patients were initially evaluated. Their mean age was 83.1 years. The patients were predominantly female (84.3%). Thirty-six patients were monitored as outpatients for periods ranging from 10 to 48 months (mean of 26.5 months). Fifteen patients were lost to follow-up. Nineteen patients died, and the mortality rate within the first year was 25.4%. Patients classified as ASA III had a mortality rate of 25.7% and ASA II patients, a rate of 12.1%. Two patients had symptomatic deep vein thrombosis; one patient had an operative wound infection; and none of the patients presented hip dislocation. Most of the patients did not experience pain. Twelve patients (33%) showed deterioration of their walking ability. Conclusion: There were no cases of hip dislocation. Patients classified as ASA III had a higher mortality rate than did patients with ASA I or II. There was a worsening of walking ability in 33% of the patients. No revision due to loosening or pain was needed for any patient. Thirty patients did not present any pain (83.3%), four presented moderate pain (11.1%) and two presented intense pain (5.5%). PMID:27022567

  4. The damping effect of cement as a potential mitigation factor of squeaking in ceramic-on-ceramic total hip arthroplasty

    PubMed Central

    Mengelle, D. E.; Ozols, A.; Fernandez, C.; Autorino, C. M.

    2016-01-01

    Objectives Studies reporting specifically on squeaking in total hip arthroplasty have focused on cementless, and not on hybrid, fixation. We hypothesised that the cement mantle of the femur might have a damping effect on the sound transmitted through the metal stem. The objective of this study was to test the effect of cement on sound propagation along different stem designs and under different fixation conditions. Methods An in vitro model for sound detection, composed of a mechanical suspension structure and a sound-registering electronic assembly, was designed. A pulse of sound in the audible range was propagated along bare stems and stems implanted in cadaveric bone femurs with and without cement. Two stems of different alloy and geometry were compared. Results The magnitudes of the maximum amplitudes of the bare stem were in the range of 10.8 V to 11.8 V, whereas the amplitudes for the same stems with a cement mantle in a cadaveric bone decreased to 0.3 V to 0.7 V, implying a pulse-attenuation efficiency of greater than 97%. The same magnitude is close to 40% when the comparison is made against stems implanted in cadaveric bone femurs without cement. Conclusion The in vitro model presented here has shown that the cement had a remarkable effect on sound attenuation and a strong energy absorption in cement mantle and bone. The visco-elastic properties of cement can contribute to the dissipation of vibro-acoustic energy, thus preventing hip prostheses from squeaking. This could explain, at least in part, the lack of reports of squeaking when hybrid fixation is used. Cite this article: F. J. Burgo, D. E. Mengelle, A. Ozols, C. Fernandez, C. M. Autorino. The damping effect of cement as a potential mitigation factor of squeaking in ceramic-on-ceramic total hip arthroplasty. Bone Joint Res 2016;5:531–537. DOI: 10.1302/2046-3758.511.BJR-2016-0058.R1. PMID:27811144

  5. Probability of mechanical loosening of the femoral component in high flexion total knee arthroplasty can be reduced by rather simple surgical techniques.

    PubMed

    van de Groes, S; de Waal-Malefijt, M; Verdonschot, N

    2014-01-01

    Some follow-up studies of high flexion total knee arthoplasties report disturbingly high incidences of femoral component loosening. Femoral implant fixation is dependant on two interfaces: the cement-implant and the cement-bone interface. The present finite-element model (FEM) is the first to analyse both the cement-implant interface and cement-bone interface. The cement-bone interface is divided into cement-cancellous and cement-cortical bone interfaces, each having their own strength values. The research questions were: (1) which of the two interfaces is more prone to failure? and (2) what is the effect of different surgical preparation techniques for cortical bone on the risk of early failure.? FEM was used in which the posterior-stabilized PFC Sigma RP-F (DePuy) TKA components were incorporated. A full weight-bearing squatting cycle was simulated (ROM=50°-155°). An interface failure index (FI) was calculated for both interfaces. The cement-bone interface is more prone to failure than the cement implant interface. When drilling holes through the cortex behind the anterior flange instead of unprepared cortical bone, the area prone to early interface failure can be reduced from 31.3% to 2.6%. The results clearly demonstrate high risk of early failure at the cement-bone interface. This risk can be reduced by some simple preparation techniques of the cortex behind the anterior flange. High-flexion TKA is currently being introduced. Some reports show high failure rates. FEM can be helpful in understanding failure of implants. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Migration and head penetration of Vitamin-E diffused cemented polyethylene cup compared to standard cemented cup in total hip arthroplasty: study protocol for a randomised, double-blind, controlled trial (E1 HIP)

    PubMed Central

    Sköldenberg, Olof; Rysinska, Agata; Chammout, Ghazi; Salemyr, Mats; Muren, Olle; Bodén, Henrik; Eisler, Thomas

    2016-01-01

    Introduction In vitro, Vitamin-E-diffused, highly cross-linked polyethylene (PE) has been shown to have superior wear resistance and improved mechanical properties when compared to those of standard highly cross-linked PE liners used in total hip arthroplasty (THA). The aim of the study is to evaluate the safety of a new cemented acetabular cup with Vitamin-E-doped PE regarding migration, head penetration and clinical results. Methods and analysis In this single-centre, double-blinded, randomised controlled trial, we will include 50 patients with primary hip osteoarthritis scheduled for THA and randomise them in a 1:1 ratio to a cemented cup with either argon gas-sterilised PE (control group) or Vitamin-E-diffused PE (vitamin-e group). All patients and the assessor of the primary outcome will be blinded and the same uncemented stem will be used for all participants. The primary end point will be proximal migration of the cup at 2 years after surgery measured with radiostereometry. Secondary end points include proximal migration at other follow-ups, total migration, femoral head penetration, clinical outcome scores and hip-related complications. Patients will be followed up at 3 months and at 1, 2, 5 and 10 years postoperatively. Results Results will be analysed using 95% CIs for the effect size. A regression model will also be used to adjust for stratification factors. Ethics and dissemination The ethical committee at Karolinska Institutet has approved the study. The first results from the study will be disseminated to the medical community via presentations and publications in relevant medical journals when the last patient included has been followed up for 2 years. Trial registration number NCT02254980. PMID:27388352

  7. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-10-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.

  8. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-06-16

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries. Laboratory testing during the tenth quarter focused on evaluation of the alkali-silica reaction of eight different cement compositions, four of which contain ULHS. The original laboratory procedure for measuring set cement expansion resulted in test specimen erosion that was unacceptable. A different expansion procedure is being evaluated. This report provides a progress summary of ASR testing. The testing program initiated in November produced questionable initial results so the procedure was modified slightly and the testing was reinitiated. The results obtained with the modified procedure showed improvement over data obtained with the original procedure, but questionable data were obtained from several of the compositions. Additional modification of test procedures for compositions containing TXI Lightweight cement are being implemented and testing is ongoing.

  9. Anaphylactic shock during cement implantation of a total hip arthroplasty in a patient with underlying mastocytosis: case report of a rare intraoperative complication.

    PubMed

    Ten Hagen, Anita; Doldersum, Pieter; van Raaij, Tom

    2016-01-01

    Cemented total hip arthroplasty (THA) is a safe and common procedure. In rare cases life threatening bone cement implantation syndrome (BCIS) may occur, which is commonly caused by pulmonary embolism (PE). We describe the rare case of a 70-year old patient who underwent an elective total hip replacement. Before surgery he was diagnosed with underlying systemic indolent mastocytosis, a rare pathological disorder that may result in anaphylaxis after massive systemic mast cell activation. Triggers may be IgE-mediated, direct mast cell activation, or unclear. Some patients may be at risk for severe non IgE-mediated reactions, such as those experienced with nonsteroidal anti-inflammatory drugs, or with perioperative muscle relaxants. During cementing of the acetabular component, our patient developed acute hypotension (blood pressure dropped from 90/50 to 60/40 mmHg, and saturation dropped from 95 to 80 %). The differential diagnosis of acute PE was excluded (no signs of breathing abnormalities during physical examination, normal arterial blood sample, and no electrocardiography or cardiac ultrasound abnormalities). The patient was diagnosed with acute anaphylactic shock, which was successfully managed by 100 % oxygen administration, rapid fluid induction, and vasoconstrictive drug therapy. He recovered hemodynamically within 15 min, did not lose consciousness, and did not develop angioedema or an urticarial rash. Forty-five minutes after onset of the symptoms, the surgical procedure was completed after inserting a press fitted uncemented femoral stem component. The patient was transported to the Intensive Care Unit (ICU) for optimal monitoring. Our patient had an uneventful recovery. Within six hours after surgery he started to ambulate following our standard fast-track rehabilitation regime. Post-operative day one he was discharged to the specialized Orthopedic Department, and after five hospital days discharged to his home. Twelve months after THA surgery our

  10. A low-cost solution for the restoration of femoral head centre during total hip arthroplasty.

    PubMed

    Hill, Janet C; Salazar-Torres, Jose J; Orr, John F; Archbold, H A Pooler; Beverland, David E

    2013-06-01

    Restoration of joint centre during total hip arthroplasty is critical. While computer-aided navigation can improve accuracy during total hip arthroplasty, its expense makes it inaccessible to the majority of surgeons. This article evaluates the use, in the laboratory, of a calliper with a simple computer application to measure changes in femoral head centres during total hip arthroplasty. The computer application was designed using Microsoft Excel and used calliper measurements taken pre- and post-femoral head resection to predict the change in head centre in terms of offset and vertical height between the femoral head and newly inserted prosthesis. Its accuracy was assessed using a coordinate measuring machine to compare changes in preoperative and post-operative head centre when simulating stem insertion on 10 sawbone femurs. A femoral stem with a modular neck was used, which meant nine possible head centre configurations were available for each femur, giving 90 results. The results show that using this technique during a simulated total hip arthroplasty, it was possible to restore femoral head centre to within 6 mm for offset (mean 1.67 ± 1.16 mm) and vertical height (mean 2.14 ± 1.51 mm). It is intended that this low-cost technique be extended to inform the surgeon of a best-fit solution in terms of neck length and neck type for a specific prosthesis.

  11. Less wear with aluminium-oxide heads than cobalt-chrome heads with ultra high molecular weight cemented polyethylene cups: a ten-year follow-up with radiostereometry.

    PubMed

    Dahl, Jon; Söderlund, Per; Nivbrant, Bo; Nordsletten, Lars; Röhrl, Stephan M

    2012-03-01

    Wear is a major contributor to osteolysis and aseptic loosening of total hip replacements (THR). Both alumina (Al(2)O(3)) and cobalt-chrome (CoCr) femoral heads are commonly used. We investigated wear comparing alumina heads to cobalt-chrome heads against conventional cemented polyethylene (PE) cups for up to ten years. Linear wear was measured with radiostereometry (RSA). Our material was derived from two prospective randomised trials that investigated fixation of femoral stems, not wear, and was evaluated retrospectively (Level III). The mean (95% CI) proximal head penetration was 0.96 mm (0.68-1.23) in the cobalt-chrome group and 0.42 mm (0.30-0.53) in the alumina group at ten years (P = 0.001). The mean (95% CI) 3D penetration was 1.07 mm (0.79-1.35) and 0.53 mm (0.38-0.63), respectively, at ten years (P = 0.001). Alumina heads performed better than cobalt-chrome heads in this study after ten-year follow-up.

  12. Small-particle-size cement

    SciTech Connect

    Ewert, D.P.; Almond, S.W.; Blerhaus, W.M. II )

    1991-05-01

    Successful remedial cementing has historically been difficult in wells with large-interval, multizone, gravel-packed completions. The reason is the inability of conventional oilfield cements to penetrate gravel packs adequately. Small-particle-size cement (SPSC) was developed to penetrate gravel packs and to provide the zonal isolation required. This paper details the laboratory work, job design, and field implementation of this new cement.

  13. Effects of Silicon on Osteoclast Cell Mediated Degradation, In Vivo Osteogenesis and Vasculogenesis of Brushite Cement

    PubMed Central

    Vahabzadeh, Sahar; Roy, Mangal; Bose, Susmita

    2015-01-01

    Calcium phosphate cements (CPCs) are being widely used for treating small scale bone defects. Among the various CPCs, brushite (dicalcium phosphate dihydrate, DCPD) cement is widely used due to its superior solubility and ability to form new bone. In the present study, we have studied the physical, mechanical, osteoclast-like-cells differentiation and in vivo osteogenic and vasculogenic properties of silicon (Si) doped brushite cements. Addition of Si did not alter the phase composition of final product and regardless of Si level, all samples included β-tricalcium phosphate (β-TCP) and DCPD. 1.1 wt. % Si addition increased the compressive strength of undoped brushite cement from 4.78±0.21 MPa to 5.53±0.53 MPa, significantly. Cellular activity was studied using receptor activator of nuclear factor κβ ligand (RANKL) supplemented osteoclast-like-cells precursor RAW 264.7 cell. Phenotypic expressions of the cells confirmed successful differentiation of RAW264.7 monocytes to osteoclast-like-cells on undoped and doped brushite cements. An increased activity of osteoclast-like cells was noticed due to Si doping in the brushite cement. An excellent new bone formation was found in all cement compositions, with significant increase in Si doped brushite samples as early as 4 weeks post implantation in rat femoral model. After 4 weeks of implantation, no significant difference was found in blood vessel formation between the undoped and doped cements, however, a significant increase in vasculgenesis was found in 0.8 and 1.1 wt. % Si doped brushite cements after 8 weeks. These results show the influence of Si dopant on physical, mechanical, in vitro osteoclastogenesis and in vivo osteogenic and vasculogenic properties of brushite cements. PMID:26855779

  14. Reducing cement's CO2 footprint

    USGS Publications Warehouse

    van Oss, Hendrik G.

    2011-01-01

    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  15. High temperature lightweight foamed cements

    DOEpatents

    Sugama, Toshifumi.

    1989-10-03

    Cement slurries are disclosed which are suitable for use in geothermal wells since they can withstand high temperatures and high pressures. The formulation consists of cement, silica flour, water, a retarder, a foaming agent, a foam stabilizer, and a reinforcing agent. A process for producing these cements is also disclosed. 3 figs.

  16. Cement Mason's Curriculum. Instructional Units.

    ERIC Educational Resources Information Center

    Hendirx, Laborn J.; Patton, Bob

    To assist cement mason instructors in providing comprehensive instruction to their students, this curriculum guide treats both the skills and information necessary for cement masons in commercial and industrial construction. Ten sections are included, as follow: related information, covering orientation, safety, the history of cement, and applying…

  17. High temperature lightweight foamed cements

    DOEpatents

    Sugama, Toshifumi

    1989-01-01

    Cement slurries are disclosed which are suitable for use in geothermal wells since they can withstand high temperatures and high pressures. The formulation consists of cement, silica flour, water, a retarder, a foaming agent, a foam stabilizer, and a reinforcing agent. A process for producing these cements is also disclosed.

  18. Cement Mason's Curriculum. Instructional Units.

    ERIC Educational Resources Information Center

    Hendirx, Laborn J.; Patton, Bob

    To assist cement mason instructors in providing comprehensive instruction to their students, this curriculum guide treats both the skills and information necessary for cement masons in commercial and industrial construction. Ten sections are included, as follow: related information, covering orientation, safety, the history of cement, and applying…

  19. [Femoral shaft fractures in children].

    PubMed

    Dietz, H-G; Schlickewei, W

    2011-05-01

    Femoral shaft fractures in children represent 1.5% of all fractures in childhood. Up to the age of 4 years, conservative treatment in a hip spica or short-term overhead traction is the therapy of choice. Femoral shaft fractures between the age of 5 and 16 years should be treated surgically. In over 90% of these cases elastic stable intramedullary nailing (ESIN) is the premier treatment option. Additional end caps can be used for unstable fractures and in length discrepancy. The external fixator and the locking plate are reserved for fractures with severe soft tissue injuries, vascular problems and some specific situations mentioned later on. By adhering to these standards good results can be achieved with a low complication rate.

  20. [Osteonecrosis of the femoral head].

    PubMed

    Lafforgue, Pierre

    2002-03-15

    The femoral head is the main location of avascular osteonecrosis. The lesion remains asymptomatic for several months or years before causing non specific hip pain. Risk factors have been identified, mainly femoral neck fractures, corticosteroid therapy and related conditions (lupus erythematosus, organ transplantations), alcohol abuse, dyslipidemia, sickle cell disease, HIV infection, caisson workers, Gaucher's disease, male sex. When typical radiological signs are lacking, MRI is the best investigation. Progression toward hip joint damage highly depends on the necrotic volume assessed at MRI. The combination of plain radiographs which help staging the severity of osteonecrosis, and MRI which indicates the prognosis of the lesion, determines the therapeutic options: symptomatic pain relief therapies or surgical treatment (core decompression, osteotomy or total hip replacement).

  1. Cementing a wellbore using cementing material encapsulated in a shell

    DOEpatents

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Floyd, III, William C.; Spadaccini, Christopher M.; Vericella, John J.; Cowan, Kenneth Michael

    2017-03-14

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  2. Cementing a wellbore using cementing material encapsulated in a shell

    DOEpatents

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Spadaccini, Christopher M.; Cowan, Kenneth Michael

    2016-08-16

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  3. [Slipped upper femoral epiphysis (SUFE)].

    PubMed

    Wirth, T

    2011-08-01

    A slipped upper femoral epiphysis (SUFE) is the most common disease of the hip among adolescents. In the light of our current knowledge on the development of coxarthrosis, it represents a first line model case that has led to a series of novel ideas in the therapy for SUFE. The development of coxarthrosis from a cam impingement, i.e., the loss of offset of the neck of the femur and degenerative damage to the acetabular lip as its early form, is seen again in the clinical picture of slipped upper femoral epiphysis. Depending on the degree of slippage, we see a varying severity of the loss of offset and thus also different extents of the potential damage to the hip joint. This knowledge is by no means new. The questions of reorientation of the epiphysis of the humeral head and thus restoration of the anatomy of the coxal end of the femur have been addressed by renowned surgeons and answered with the development of widely varying procedures for surgical correction. However, within the framework of the surgical techniques introduced for treatment of impingement syndromes of the hip, these therapeutic options have been supplemented and broadened. The current discussion about the best therapeutic strategies emphasizes the fascination of the clinical entity of upper femoral epiphysis and constitutes a central component of this article. © Georg Thieme Verlag KG Stuttgart · New York.

  4. Proximal femoral reconstruction after aseptic loosening following proximal femoral replacement for Ewing sarcoma: a case report with one-year follow-up.

    PubMed

    Schoof, Benjamin; Jakobs, Oliver; Gehrke, Thorsten; Gebauer, Matthias

    2014-01-01

    We report the case of a 30-year-old patient initially treated for a proximal femoral Ewing's sarcoma when 12 years old. Index treatment comprised tumour resection and total hip arthroplasty. Two years later revision for aseptic loosening was performed. Subsequently, six further surgical revisons were performed for varying causes. At the age of 23 years the proximal femur was resected and a proximal femoral endoprosthesis implanted.Eighteen years after initial diagnosis the patient presented with recurrent aseptc loosening. Both the proximal femur and acetabulum were reconstructed. For acetabular reconstruction a structural allograft and a tantalum cup were utilised. Reconstruction of the femur utilsed extensive wire mesh and circlage wiring with impaction bone allograft into which a femoral stem was implanted.At one-year follow-up the patient was pain free, had no evidence of infection with satisfactory radiographs and no evidence of implant loosening. This is the first case reporting an extended proximal femoral reconstruction with a wire mesh in combination with impaction bone grafting in an aseptic loosened proximal femoral replacement following Ewing's Sarcoma.

  5. Late Disassembly of Femoral Head and Neck of A Modular Primary Total Hip Arthroplasty

    PubMed Central

    Ahmed, Parvej; Kumar, Dinesh

    2015-01-01

    Introduction: Modular total hip arthroplasty system are now widely used, as these components increase the flexibility during primary and revision total hip arthoplasty. But this modularity itself associated with some risk of intraoperative and postoperative complications. Case Report: We report a case of late disassembly of a primary total arthroplasty in a 42 years old patient five years after the replacement surgery where the femoral head remained in the acetabular socket. Conclusion: Femoral head should be solidly impacted onto the stem and confirm that it has been assembled correctly before reduction. PMID:27299010

  6. Transient and residual stresses and displacements in self-curing bone cement - Part I: characterization of relevant volumetric behavior of bone cement.

    PubMed

    Ahmed, A M; Pak, W; Burke, D L; Miller, J

    1982-02-01

    In this first part of a two-part report, some aspects of the volumetric behavior of bone cement during its curing process are examined as a prelude to an analysis for the transient and residual stresses and displacements in stem fixation systems. Experiments show that stress generation in the cement is associated with its temperature while curing and that during the cooling phase, the stresses are mainly due to thermal as opposed to bulk shrinkage. The appropriate coefficient of thermal expansion of bone cement has been evaluated from measurements in a simulated fixation system in conjuction with a thermoelastic analysis.

  7. Numerical Optimization of the Position in Femoral Head of Proximal Locking Screws of Proximal Femoral Nail System; Biomechanical Study.

    PubMed

    Konya, Mehmet Nuri; Verim, Özgür

    2017-09-29

    Proximal femoral fracture rates are increasing due to osteoporosis and traffic accidents. Proximal femoral nails are routinely used in the treatment of these fractures in the proximal femur. To compare various combinations and to determine the ideal proximal lag screw position in pertrochanteric fractures (Arbeitsgemeinschaft für Osteosynthesefragen classification 31-A1) of the femur by using optimized finite element analysis. Biomechanical study. Computed tomography images of patients' right femurs were processed with Mimics. Afterwards a solid femur model was created with SolidWorks 2015 and transferred to ANSYS Workbench 16.0 for response surface optimization analysis which was carried out according to anterior-posterior (-10°femoral nail hole, the small diameter portion of stem joints with a large diameter and lag screw mounts to the stem. The most suitable position of the proximal lag screw was found at the middle position of the tip-apex distance (20 mm) and femoral neck (anterior-posterior, inferior-superior=0°), according to von Mises compression stress values occurring on the fracture line. In our study, we couldn't find any correlation between proximal lag screw movement and tip-apex distance on stresses of the fracture surfaces, but the proximal lag screw

  8. Cement composition and sulfate attack