Posterior stability in fixed-bearing versus mobile-bearing total knee replacement: a radiological comparison of two implants.

PubMed

Siebold, R; Louisia, S; Canty, J; Bartlett, R J

2007-02-01

Posterior tibial translation in total knee replacement (TKR) could be one major factor for PE wear, delamination and loosening of the tibial component due to increased shear forces and component-to-bone interface stress. The aim of this study was to assess the posterior stability of two different designs of posterior cruciate ligament (PCL) substituting TKR. In this non-randomised consecutive study 43 patients underwent TKR for primary osteoarthritis. Twenty-six patients in group FB received a deep-dished fixed-bearing Duracon TKR (Howmedica, Rutherford, NJ, USA) and 17 patients in group MB a deep-dished rotating mobile-bearing Duracon TKR. In both groups the PCL was resected. All patients had pre- and postoperative kneeling stress radiographs and were clinically evaluated with the Knee Society Score. Posterior tibial translation was measured by tracing a line along the posterior tibial cortex in relationship to the posterior edge of Blumensaat's line. The average follow-up was 13 months for group FB and 11 months for group MB. Both groups demonstrated a statistical significant increase of the mean posterior tibial translation on kneeling stress X-ray of 4.1 mm (group FB) (P < 0.001) and of 6.6 mm (group MB) (P < 0.001) compared to pre-operative. Group MB showed a significant higher posterior draw (P < 0.008). Clinical assessment using the Knee Society Score showed comparable short-term results. The deep-dished fixed-bearing TKR as well as the deep-dished rotating mobile-bearing TKR demonstrated significant posterior tibial translation on kneeling stress X-ray. It remains to be determined what amount of joint play is optimal for clinical function and to minimise shear forces and PE wear. Moreover the amount of posterior tibial translation was significantly higher with the mobile-bearing insert, which could be directly related to the asymmetric rotational mobility of the tibial insert. A long-term follow-up is necessary to investigate whether our findings correlate

Introduction of a new mobile-bearing total knee prosthesis: minimum three year follow-up of an RCT comparing it with a fixed-bearing device.

PubMed

Beard, D J; Pandit, H; Price, A J; Butler-Manuel, P A; Dodd, C A F; Murray, D W; Goodfellow, J W

2007-12-01

As part of the step-wise validation of a new prosthesis (TMK), we previously published the 1 year results of a randomised controlled trial in patients undergoing bilateral knee replacement [Price A., Rees J., Beard D., Juszczak E. et al. A mobile-bearing total knee prosthesis compared with a fixed-bearing prosthesis. JBJS B 2003;85-B-1:62-7.]. Forty patients had the new mobile-bearing prosthesis implanted in one knee and an established fixed-bearing device in the other (AGC). We now report the 3 year status of these patients and, in addition, review a separate multi-centre cohort of 172 patients who had undergone unilateral arthroplasty with the TMK. No significant differences were found in outcome (American Knee Society Score and Oxford Knee Score) between the two prostheses. The greater incidence of "clicking" in the mobile-bearing knee, reported in the previous review, persisted (TMK=48%, AGC=30%). The presence of this mechanical noise was found to have no relationship with outcome in either of the prostheses. The unilateral cohort study showed an acceptable complication rate for the new prosthesis, although some patients reported subjective instability. The method of controlled introduction of the TMK, of which this constitutes a further step, has allowed us to assess the significance of a reported problem (clicking) and to provide scientific data from which other surgeons can decide about use of the implant.

Femoro-tibial kinematics after TKA in fixed- and mobile-bearing knees in the sagittal plane.

PubMed

Daniilidis, Kiriakos; Höll, Steffen; Gosheger, Georg; Dieckmann, Ralf; Martinelli, Nicolo; Ostermeier, Sven; Tibesku, Carsten O

2013-10-01

Lack of the anterior cruciate ligament in total knee arthroplasty results in paradoxical movement of the femur as opposed to the tibia under deep flexion. Total knee arthroplasty with mobile-bearing inlays has been developed to provide increased physiological movement of the knee joint and to reduce polyethylene abrasion. The aim of this study was to perform an in vitro analysis of the kinematic movement in the sagittal plane in order to show differences between fixed- and mobile-bearing TKA in comparison with the natural knee joint. Seven knee joints of human cadaver material were used in a laboratory experiment. Fixed- and mobile-bearing inlays were tested in sequences under isokinetic extension in so-called kinemator for knee joints, which can simulate muscular traction power by the use of hydraulic cylinders, which crossover the knee joint. As a target parameter, the a.p. translation of the tibio-femoral relative movement was measured in the sagittal plane under ultrasound (Zebris) control. The results show a reduced tibial a.p. translation in relation to the femur in the bearing group compared to the natural joint. In the Z-axis, between 110° and 50° of flexion, linear movement decreases towards caudal movement under extension. Admittedly, the study did not show differences in the movement pattern between "mobile-bearing" and "fixed-bearing" prostheses. Results of this study cannot prove functional advantages of mobile-bearing prostheses for the knee joint kinematic after TKA. Both types of prostheses show typical kinematics of an anterior instability, hence they were incapable of performing physiological movement.

Increased risk of aseptic loosening for 43,525 rotating-platform vs. fixed-bearing total knee replacements

PubMed Central

Gothesen, Oystein; Lygre, Stein Hakon L; Lorimer, Michelle; Graves, Stephen; Furnes, Ove

2017-01-01

Background and purpose — Given similar functional outcomes with mobile and fixed bearings, a difference in survivorship may favor either. This study investigated the risk of aseptic loosening for the most used subtypes of mobile-bearing rotating-platform knees, in Norway and Australia. Patients and methods — Primary TKRs reported to the Norwegian and Australian joint registries, between 2003 and 2014, were analyzed with aseptic loosening as primary end-point and all revisions as secondary end-point. We hypothesized that no difference would be found in the rate of revision between rotating-platform and the most used fixed-bearing TKRs, or between keeled and non-keeled tibia. Kaplan–Meier estimates and curves, and Cox regression relative risk estimates adjusted for age, sex, and diagnosis were used for comparison. Results — The rotating-platform TKRs had an increased risk of revision for aseptic loosening compared with the most used fixed-bearing knees, in Norway (RR =6, 95% CI 4–8) and Australia (RR =2.1, 95% CI 1.8–2.5). The risk of aseptic loosening as a reason for revision was highest in Norway compared with Australia (RR =1.7, 95% CI 1.4–2.0). The keeled tibial component had the same risk of aseptic loosening as the non-keeled tibia (Australia). Fixation method and subtypes of the tibial components had no impact on the risk of aseptic loosening in these mobile-bearing knees. Interpretation — The rotating-platform TKRs in this study appeared to have a higher risk of revision for aseptic loosening than the most used fixed-bearing TKRs. PMID:28929828

International comparative evaluation of fixed-bearing non-posterior-stabilized and posterior-stabilized total knee replacements.

PubMed

Comfort, Thomas; Baste, Valborg; Froufe, Miquel Angel; Namba, Robert; Bordini, Barbara; Robertsson, Otto; Cafri, Guy; Paxton, Elizabeth; Sedrakyan, Art; Graves, Stephen

2014-12-17

Differences in survivorship of non-posterior-stabilized compared with posterior-stabilized knee designs carry substantial economic consequences, especially with limited health-care resources. However, these comparisons have often been made between relatively small groups of patients, often with short-term follow-up, with only small differences demonstrated between the groups. The goal of this study is to compare the outcomes of non-posterior-stabilized and posterior-stabilized total knee arthroplasties with use of a unique collaboration of multiple established knee arthroplasty registries. A distributed health data network was developed by the International Consortium of Orthopaedic Registries and was used in this study to reduce barriers to participation (such as security, propriety, legal, and privacy issues) compared with a centralized data warehouse approach. The study included only replacements in osteoarthritis patients who underwent total knee procedures involving fixed-bearing devices from 2001 to 2010. The outcome of interest was time to first revision. On average, not resurfacing showed a more harmful effect than resurfacing did when posterior-stabilized and non-posterior-stabilized knee replacements were compared, while the risk of revision for posterior-stabilized compared with non-posterior-stabilized knees was highest in year zero to one, followed by year one to two, years eight through ten, and years two through eight. Posterior-stabilized knees did significantly worse than non-posterior-stabilized knees did when the patella was not resurfaced. This difference was most pronounced in the first two years (year zero to one: hazard ratio [HR] = 2.15, 95% confidence interval [CI] = 1.56 to 2.95, p < 0.001; year one to two: HR = 1.61, 95% CI = 1.48 to 1.75, p < 0.001). When the patella was resurfaced, posterior-stabilized knees did significantly worse than non-posterior-stabilized knees did. This was again most pronounced in the first two years (year zero

Mobile vs. fixed bearing unicondylar knee arthroplasty: A randomized study on short term clinical outcomes and knee kinematics.

PubMed

Li, Ming G; Yao, Felix; Joss, Brendan; Ioppolo, James; Nivbrant, Bo; Wood, David

2006-10-01

The literature contains limited yet controversial information regarding whether a fixed or a mobile bearing implant should be used in unicompartmental knee arthroplasty (UKA). This randomized study was to further document the performance and comparison of the two designs. Fifty-six knees in 48 patients (mean age of 72 years) undergoing medial UKA were randomized into a fixed bearing (Miller/Galante) or a mobile bearing (Oxford) UKA. The 2 year clinical outcomes (clinical scores), radiographic findings, and weight bearing knee kinematics (assessed using RSA) were compared between the two groups. The mobile bearing knees displayed a larger and an incrementally increased tibial internal rotation (4.3 degrees, 7.6 degrees, 9.5 degrees vs. 3.0 degrees, 3.0 degrees, 4.2 degrees respectively at 30 degrees, 60 degrees, 90 degrees of knee flexion) compared to the fixed ones. The medial femoral condyle in the mobile bearing knees remained 2 mm from the initial position vs. a 4.2 mm anterior translation in the fixed bearing knees during knee flexion. The contact point in the mobile bearing implant moved 2 mm posteriorly vs. a 6 mm anterior movement in the other group. The mobile bearing knees had a lower incidence of radiolucency at the bone implant interface (8% vs. 37%, p < 0.05). The incidence of lateral compartment OA and progression of OA at patello-femoral joint were equal. No differences were found regarding Knee Society Scores, WOMAC, and SF-36 scores (p > 0.05). This study indicates that mobile bearing knees had a better kinematics, a lower incidence of radiolucency but not yet a better knee function at 2 years.

Unsatisfactory clinical outcomes of second-generation mobile bearing floating platform total knee arthroplasty: comparing outcomes with fixed bearing after five years minimum.

PubMed

Yoon, Jung-Ro; Yang, Jae-Hyuk

2018-03-20

The purpose of this retrospective study was to analyze and compare the clinical and radiologic outcomes of fixed bearing ultracongruent (UC) insert total knee arthroplasty (TKA) and mobile bearing (MB) floating platform TKA using the navigation-assisted gap balancing technique with a minimum follow-up of five years. The study retrospectively enrolled 105 patients who received the UC type fixed bearing insert (group 1) and 95 patients who received the floating platform MB insert (group 2) during the period from August 2009 to June 2012. All surgery was performed using the navigation-assisted gap balancing technique. For strict assessment of gap measurements, the offset-type-force-controlled-spreader-system was used. Radiologic and clinical outcomes were assessed before operation and at the most recent follow-up using the Knee Society Score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. For statistical analysis, paired sample t tests were used. A p value less than 0.05 was considered significant. Although the radiologic alignments were satisfactory for both groups (99/105 [94%] cases were neutral for group 1 and 90/95 [94%] for group 2), the functional and total WOMAC scores were inferior in group 2 (p < 0.05). There were two cases of insert breakage in group 2 that required bearing exchange. The Kaplan-Meier survivorship rates for groups 1 and 2 at 77 months were 100.0 and 97.9%, respectively. Second-generation MB floating platform TKA cases did not have satisfactory outcomes. There were two cases of insert breakage, which required bearing exchange. Other patients who underwent surgery with second-generation MB floating platform were encouraged to avoid high knee flexion activities, resulting in lower clinical performance.

Early clinical results of a high-flexion, posterior-stabilized, mobile-bearing total knee arthroplasty: a US investigational device exemption trial.

PubMed

Scuderi, Giles R; Hedden, David R; Maltry, John A; Traina, Steven M; Sheinkop, Mitchell B; Hartzband, Mark A

2012-03-01

Between May 2001 and June 2004, 388 total knee arthroplasty cases were enrolled in a prospective, randomized, multicenter investigational device exemption trial. Patients received either the investigational high-flexion mobile-bearing knee or a fixed-bearing control. At 2 to 4 years of follow-up, results in 293 patients with degenerative joint disease were compared using Knee Society Assessment and Function scores, radiographic results, complications analysis, and survival estimates. The mobile-bearing and fixed-bearing groups demonstrated similar, significant improvement over preoperative assessments in Knee Scores, maximum flexion, and range of motion. One mobile-bearing arthroplasty required revision. Radiographic results were unremarkable, and implant-related complications were rare in both groups. At this early follow-up, the investigational high-flexion mobile-bearing knee and its fixed-bearing counterpart demonstrated comparable, effective performance. Copyright © 2012 Elsevier Inc. All rights reserved.

Factors affecting the impingement angle of fixed- and mobile-bearing total knee replacements: a laboratory study.

PubMed

Walker, Peter S; Yildirim, Gokce; Sussman-Fort, Jon; Roth, Jonathan; White, Brian; Klein, Gregg R

2007-08-01

Maximum flexion-or impingement angle-is defined as the angle of flexion when the posterior femoral cortex impacts the posterior edge of the tibial insert. We examined the effects of femoral component placement on the femur, the slope angle of the tibial component, the location of the femoral-tibial contact point, and the amount of internal or external rotation. Posterior and proximal femoral placement, a more posterior femoral-tibial contact point, and a more tibial slope all increased maximum flexion, whereas rotation reduced it. A mobile-bearing knee gave results similar to those of the fixed-bearing knee, but there was no loss of flexion in internal or external rotation if the mobile bearing moved with the femur. In the absence of negative factors, a flexion angle of 150 degrees can be reached before impingement.

Mobile-bearing knees reduce rotational asymmetric wear.

PubMed

Ho, Fang-Yuan; Ma, Hon-Ming; Liau, Jiann-Jong; Yeh, Chuan-Ren; Huang, Chun-Hsiung

2007-09-01

Polyethylene wear of bearing components is the most common long-term complication in total knee arthroplasty. One would anticipate differing kinematics would generate different wear patterns (including wear type, degree, and symmetry) on the articulating surface of mobile-bearing and fixed-bearing inserts. Because mobile-bearing designs facilitate movement of the insert relative to the tray when the knee rotates, we hypothesized mobile-bearing designs would reduce the incidence of rotational asymmetric wear. We examined 51 worn tibial inserts, including 15 from mobile-bearing rotating-platform posterior-cruciate-sacrificing dished prostheses and 36 from fixed-bearing posterior-cruciate-retaining flat prostheses, which were retrieved at revision surgery with an average implantation time of 115 months. We divided wear types into low-grade wear (burnishing, abrasion, and cold flow) and high-grade wear (scratching, pitting, metal embedding, and delamination) to assess wear degree of polyethylene. To assess symmetry of wear, the insert surface was divided into medial and lateral sides and each side was further divided into three equal zones along the anteroposterior direction. Low-grade wear was more common in mobile-bearing knees, whereas high-grade wear was more common in fixed-bearing knees. We identified no internal/external rotational asymmetric wear or anteroposterior asymmetric wear in mobile-bearing knees.

No difference between fixed- and mobile-bearing total knee arthroplasty in activities of daily living and pain: a randomized clinical trial.

PubMed

Amaro, Joicemar Tarouco; Arliani, Gustavo Gonçalves; Astur, Diego Costa; Debieux, Pedro; Kaleka, Camila Cohen; Cohen, Moises

2017-06-01

Until now, there are no definitive conclusions regarding functional differences related to middle- and long-term everyday activities and patient pain following implantation of mobile- and fixed-platform tibial prostheses. The aim of this study was to determine whether there are middle-term differences in knee function and pain in patients undergoing fixed- and mobile-bearing total knee arthroplasty (TKA). Eligible patients were randomized into two groups: the first group received TKA implantation with a fixed tibial platform (group A); the second group received TKA with a mobile tibial platform (group B). Patients were followed up (2 years), and their symptoms and limitations in daily living activities were evaluated using the Knee Outcome Survey-Activities of Daily Living Scale (ADLS), in addition to pain evaluation assessed using the pain visual analogue scale (VAS). There were no significant differences in function and symptoms in the ADLS and VAS between the study groups. The type of platform used in TKA (fixed vs. mobile) does not change the symptoms, function or pain of patients 2 years post-surgery. Although mobile TKAs may have better short-term results, at medium- and long-term follow-up they do not present important clinical differences compared with fixed-platform TKAs. This information is important so that surgeons can choose the most suitable implant for each patient. Randomized clinical trial, Level I.

Midterm Clinical and Radiographic Results of Mobile-Bearing Revision Total Knee Arthroplasty.

PubMed

Kim, Raymond H; Martin, J Ryan; Dennis, Douglas A; Yang, Charlie C; Jennings, Jason M; Lee, Gwo-Chin

2017-06-01

Constrained implants are frequently required in revision total knee arthroplasty (TKA) and are associated with an increase in aseptic component loosening and damage or wear to the constraining mechanisms, compared with primary TKA. The purpose of the following study was to evaluate the midterm clinical and radiographic results including the incidence of bearing complications in a group of patients undergoing revision TKA using mobile-bearing revision TKA implants. We retrospectively reviewed 316 consecutive mobile-bearing revision TKAs performed at 2 centers between 2006 and 2010. There were 183 women and 133 men with a mean age of 66 years. The patients were evaluated clinically using the Knee Society scores. A radiographic analysis was performed. Bearing specific complications (ie, instability or dislocation) were recorded. Patients were followed-up for a minimum of 24 months and a median of 59.88 months (range 24-121.2). The average Knee Society knee score and function scores increased from 40.8 and 47.9 points preoperatively to 80 points and 70.3 points, respectively (P < .01). The average knee flexion improved from 105.6° preoperatively to 117.4° postoperatively (P < .01). Eight patients required subsequent implant revision. No cases of bearing complications were observed. Revision TKA using mobile-bearing revision components demonstrated favorable midterm clinical and radiographic results with no occurrence of bearing instability or dislocation. Longer follow-up is required to evaluate for potential advantages of mobile-bearings over fixed-bearing revision components in terms of polyethylene wear reduction, reduced stress transmission across fixation interfaces, and reduced stress on the polyethylene post. Copyright © 2017 Elsevier Inc. All rights reserved.

[Atraumatic dislocation in mobile-bearing total knee arthroplasty: two case reports].

PubMed

Schuh, A; Hönle, W

2007-10-01

Atraumatic dislocation following total knee arthroplasty (TKA) is a rare condition. Severe complications after dislocation are lesion of the vascular-nerve bundle, compartment syndrome or amputation. The benefit of TKA with mobile-bearing are an improvement of the range of motion and better articulation. In comparison to fixed-bearing TKA there is the risk of dislocation or breakage of the polyethylene insert. We present two cases with dislocation following TKA with mobile-bearing. In both cases preoperatively there was a significant weakening of the function of the quadriceps muscle. During revision of the TKA severe damage with multiple scratches of the polyethylene onlay could be detected. The damage of the PE onlay could especially be found at the tibial aspect. Follow-up showed an uneventful course after conversion to fixed-bearing polyethylen component. In cases of dislocation following TKA with mobile-bearing operative revision is recommended to exchange the damaged PE onlay and prevent increased wear. TKA with mobile-bearing should be reserved only for cases with a good quadriceps muscle function.

Preoperative Patellofemoral Chondromalacia is Not a Contraindication for Fixed-Bearing Medial Unicompartmental Knee Arthroplasty.

PubMed

Adams, Alexander J; Kazarian, Gregory S; Lonner, Jess H

2017-06-01

Patellofemoral chondromalacia (PFCM) has historically been considered a contraindication for unicompartmental knee arthroplasty (UKA), but there is limited data assessing PFCM's impact on the results of fixed-bearing UKA. Our objective was to assess the impact of medial patellar and/or medial trochlear PFCM on overall and patellofemoral-specific 2-year outcomes after fixed-bearing medial UKA. Intraoperative notes defined the presence and location of PFCM during fixed bearing medial UKA. Outcome measures included the New Knee Society Score (NKSS), Kneeling Ability Score (KAS) and Forgotten Joint Score (FJS-12). Thirty-one knees with PFCM (PFCM group), and 52 knees without PFCM (N-PFCM group) were included for analysis. Mann-Whitney U tests assessed the statistical significance of observed differences, and a Bonferroni correction was applied, adjusting threshold for significance to P = .005. At minimum follow-up of 2 years, no statistical differences were detected between the N-PFCM and PFCM groups in the postoperative NKSS (159 vs 157, P = .731), preoperative to postoperative NKSS change (P = .447), FJS-12 (70.5 vs 67.6, P = .471), or KAS (71% vs 65%, P = .217). Patients with isolated patellar chondromalacia (n = 13) demonstrated trends toward worse outcomes according to NKSS (147, P = .198), FJS-12 (58, P = .094), and KAS (46%, P = .018), but were statistically insignificant. No failures occurred in either group. Functional outcomes of fixed-bearing medial UKA are not adversely impacted by the presence of PFCM involving the medial patellar facet and/or medial or central trochlea. Further follow-up is needed to determine longer-term implications of fixed-bearing medial UKA in patients with PFCM. Copyright © 2017 Elsevier Inc. All rights reserved.

Mobile-bearing TKA improved the anteroposterior joint stability in mid-flexion range comparing to fixed-bearing TKA.

PubMed

Minoda, Yukihide; Ikebuchi, Mitsuhiko; Mizokawa, Shigekazu; Ohta, Yoichi; Nakamura, Hiroaki

2016-11-01

Proper anteroposterior (AP) joint displacement is an important indicator of good clinical outcome following total knee arthroplasty (TKA). We hypothesized that a newly introduced mobile-bearing posterior stabilized (PS) prosthesis reduces the AP joint displacement. The aim of this study is to compare the AP joint displacement between a newly introduced mobile-bearing PS TKA in one knee and a conventional fixed-bearing PS TKA in other knee. 82 knees in 41 patients who had bilateral TKAs were investigated. All the patients received a conventional fixed-bearing PS prosthesis in one knee and a highly congruent mobile-bearing PS prosthesis in the other knee. AP joint displacement was measured using the KT-2000 arthrometer, at 30° and 75° in flexion, at average of 3.3 years after the operation. AP joint displacements at 30° in flexion were 6 ± 3 mm in the knees with the mobile-bearing PS prosthesis and 9 ± 4 mm in the knee with fixed-bearing PS prosthesis (p < 0.001). AP joint displacements at 75° in flexion were 4 ± 2 mm in the knees with the mobile-bearing PS prosthesis and 6 ± 3 mm in the knee with fixed-bearing PS prosthesis (p < 0.001). This study suggested that the design of the prosthesis can improve the AP joint stability in mid-flexion range.

No difference in joint awareness after mobile- and fixed-bearing total knee arthroplasty: 3-year follow-up of a randomized controlled trial.

PubMed

Schotanus, M G M; Pilot, P; Vos, R; Kort, N P

2017-12-01

To compare the patients ability to forget the artificial knee joint in everyday life who were randomized to be operated for mobile- or fixed-bearing total knee arthroplasty (TKA). This single-center randomized controlled trial evaluated the 3-year follow-up of the cemented mobile- and fixed-bearing TKA from the same brand in a series of 41 patients. Clinical examination was during the pre-, 6-week, 6-month, 1-, 2- and 3-year follow-up containing multiple patient-reported outcome measures (PROMs) including the 12-item Forgotten Joint Score (FJS-12) at 3 years. Effect size was calculated for each PROM at 3-year follow-up to quantify the size of the difference between both bearings. At 3-year follow-up, general linear mixed model analysis showed that there were no significant or clinically relevant differences between the two groups for all outcome measures. Calculated effect sizes were small (<0.3) for all the PROMs except for the FJS-12; these were moderate (0.5). The results of this study demonstrate that joint awareness was slightly lower in patients operated with the MB TKA with comparable improved clinical outcome and PROMs at 3-year follow-up. Measuring joint awareness with the FJS-12 is useful and provides more stringent information at 3-year follow-up compared to other PROMs and should be the PROM of choice at each follow-up after TKA. Level I, randomized controlled trial.

Kinematic comparison between mobile-bearing and fixed-bearing inserts in NexGen legacy posterior stabilized flex total knee arthroplasty.

PubMed

Shi, Kenrin; Hayashida, Kenji; Umeda, Naoya; Yamamoto, Kengo; Kawai, Hideo

2008-02-01

Femoral component rollback and tibial rotation were evaluated using lateral radiographs taken during passive knee flexion under fluoroscopy in NexGen Legacy Posterior Stabilized Flex (Zimmer, Warsaw, Ind) total knee arthroplasties (TKAs; 30 with mobile insert and 26 with fixed insert). Measured maximal flexion angle demonstrated no significant differences. Femoral component rollback was observed predominantly in TKAs with fixed insert in more than 45 degrees flexion and correlated with maximal flexion angle in each group. Tibial internal rotation was more significant in TKAs with mobile insert in maximal flexion. However, tibial internal rotation from 90 degrees to maximal flexion, which demonstrated correlation with maximal flexion angle in each group, did not show significant difference. The kinematic differences between 2 inserts seemed to have little relevance to the maximal flexion angle.

Comparison of Alignment Correction Angles Between Fixed-Bearing and Mobile-Bearing UKA.

PubMed

Inoue, Atsuo; Arai, Yuji; Nakagawa, Shuji; Inoue, Hiroaki; Yamazoe, Shoichi; Kubo, Toshikazu

2016-01-01

Good outcomes have been reported with both fixed-bearing and mobile-bearing unicompartmental knee arthroplasty (UKA). However, overcorrected alignment could induce the progression of arthritis on the non-arthroplasty side. Changes of limb alignment after UKA with both types of bearings (fixed bearing: 24 knees, mobile bearing: 28 knees) were investigated. The mean difference between the preoperative standing femoral-tibial angle (FTA) and postoperative standing FTA was significantly larger in mobile bearing UKA group. In fixed-bearing UKA, there must be some laxity in MCL tension so that a 2-mm tension gauge can be inserted. In mobile-bearing UKA, appropriate MCL tension is needed to prevent bearing dislocation. This difference in MCL tension may have caused the difference in the correction angle between the groups. Copyright © 2016 Elsevier Inc. All rights reserved.

P.F.C Sigma® cruciate retaining fixed-bearing versus mobile-bearing knee arthroplasty: a prospective comparative study with minimum 10-year follow-up.

PubMed

Riaz, O; Aqil, A; Sisodia, G; Chakrabarty, G

2017-12-01

To prospectively compare long-term clinical and radiological outcomes following a cruciate retaining fixed-bearing (FB) and a mobile-bearing (MB) primary total knee replacement (TKR). We prospectively reviewed 113 TKRs in 99 patients (14 bilateral) with a PFC sigma cruciate retaining rotating platform system, at an average follow-up of 11.1 years (range 10-12). Results were contrasted with those from 89 TKRs in 72 patients (17 bilateral) with a PFC sigma cruciate fixed-bearing prosthesis, at an average follow-up of 12.1 years (range 10-14.1). Outcomes collected included pre- and post-operative range of motion, Oxford Knee Scores, complications encountered, as well as radiographical assessments of polyethylene wear. In the MB group, mean Oxford Knee Scores improved from 16 pre-operatively to 42 at final follow-up. The mean range of motion was 115° (75-130). In the FB group, mean Oxford Knee Scores improved from 16.2 pre-operatively to 42.5 at final follow-up. The mean range of motion was 111.2 (80-135) degrees at final follow-up. We failed to elicit an objectively demonstrable clinical difference between the MB- and FB-implanted knees. Similarly, radiological benefits of the MB implants with regard to polyethylene wear were not evident at a minimum 10-year follow-up.

Comparison of in vivo polyethylene wear particles between mobile- and fixed-bearing TKA in the same patients.

PubMed

Minoda, Yukihide; Hata, Kanako; Ikebuchi, Mitsuhiko; Mizokawa, Shigekazu; Ohta, Yoichi; Nakamura, Hiroaki

2017-09-01

Polyethylene wear particle generation is one of the most important factors that affects the mid- to long-term results of total knee arthroplasties (TKA). Mobile-bearing total knee prostheses were developed to reduce polyethylene wear generation. However, whether mobile-bearing prostheses actually generate fewer polyethylene wear particles than fixed-bearing prostheses remains controversial. The aim of this study was to compare, within individual patients, the in vivo polyethylene wear particles created by a newly introduced mobile-bearing prosthesis in one knee and a conventional fixed-bearing prosthesis in other knee. Eighteen patients receiving bilateral TKAs to treat osteoarthritis were included. The synovial fluid was obtained from 36 knees at an average of 3.5 years after the operation. The in vivo polyethylene wear particles were isolated from the synovial fluid using a previously validated method and examined using a scanning electron microscope and an image analyser. The size and shape of the polyethylene wear particles from the mobile-bearing prostheses were similar to those from the conventional fixed-bearing prostheses. Although the number of wear particles from the mobile-bearing prosthesis (1.63 × 10 7  counts/knee) appeared smaller than that from the fixed-bearing prosthesis (2.16 × 10 7  counts/knee), the difference was not statistically significant. The current in vivo study shows that no statistically significant differences were found between the polyethylene wear particles generated by a newly introduced mobile-bearing PS prosthesis and a conventional fixed-bearing PS prosthesis during the early clinical stage after implantation. Therapeutic study, Level III.

Design forms of total knee replacement.

PubMed

Walker, P S; Sathasivam, S

2000-01-01

The starting point of this article is a general design criterion applicable to all types of total knee replacement. This criterion is then expanded upon to provide more specifics of the required kinematics, and the forces which the total knee must sustain. A characteristic which differentiates total knees is the amount of constraint which is required, and whether the constraint is translational or rotational. The different forms of total knee replacement are described in terms of these constraints, starting with the least constrained unicompartments to the almost fully constrained fixed and rotating hinges. Much attention is given to the range of designs in between these two extreme types, because they constitute by far the largest in usage. This category includes condylar replacements where the cruciate ligaments are preserved or resected, posterior cruciate substituting designs and mobile bearing knees. A new term, 'guided motion knees', is applied to the growing number of designs which control the kinematics by the use of intercondylar cams or specially shaped and even additional bearing surfaces. The final section deals with the selection of an appropriate design of total knee for specific indications based on the design characteristics.

Comparison of the clinical outcomes after total knee arthroplasty with the LCS rotating platform mobile bearing knee system and the PFC Sigma RP-F mobile bearing knee system.

PubMed

Kwak, Ju-Yeong; Jeong, Jae-Heon; Lee, Sang-Hak; Jung, Ho-Joong; Jung, Young-Bok

2012-12-01

We compared clinical outcomes after total knee arthroplasty with the Low Contact Stress (LCS) rotating platform mobile bearing knee system and the Press Fit Condylar Sigma rotating platform high flexion (PFC Sigma RP-F) mobile bearing knee system. Fifty cases of total knee arthroplasty were performed with the PFC Sigma RP-F mobile bearing knee system and sixty-one cases were performed with the LCS mobile bearing total knee arthroplasty. The average duration of follow-up was 2.9 years. The mean Hospital for Special Surgery (HSS) knee score was 62.1 (range, 52 to 75) in the LCS group and 61.9 (range, 50 to 74) in the Sigma RP-F group preoperatively, and 90.1 (range, 84 to 100) in the LCS group and 89.8 (range, 83 to 100) in the Sigma RP-F group at the final follow-up. The mean preoperative flexion contracture was 6.7° (range, 0° to 10°) in the LCS group and 9.3° (range, 0° to 15°) in the Sigma RP-F group preoperatively. The mean range of motion was 124.6° (range, 105° to 150°) in the LCS group and 126.1° (range, 104° to 145°) in the Sigma RP-F group at the final follow-up. After a minimum duration of follow-up of two years, we found no significant differences between the two groups with regard to the range of knee motion or the clinical or radiographic results.

Influence of conformity on the wear of total knee replacement: An experimental study

PubMed Central

Brockett, Claire L; Carbone, Silvia; Fisher, John; Jennings, Louise M

2017-01-01

Wear of total knee replacement continues to be a significant factor influencing the clinical longevity of implants. Historically, failure due to delamination and fatigue directed design towards more conforming inserts to reduce contact stress. As new generations of more oxidatively stable polyethylene have been developed, more flexibility in bearing design has been introduced. The aim of this study was to investigate the effect of insert conformity on the wear performance of a fixed bearing total knee replacement through experimental simulation. Two geometries of insert were studied under standard gait conditions. There was a significant reduction in wear with reducing implant conformity. This study has demonstrated that bearing conformity has a significant impact on the wear performance of a fixed bearing total knee replacement, providing opportunities to improve clinical performance through enhanced material and design selection. PMID:29251167

Different femorotibial contact points between fixed- and mobile-bearing TKAs do not show clinical impact.

PubMed

van Stralen, R A; Heesterbeek, P J C; Wymenga, A B

2015-11-01

In anteroposterior (AP)-gliding mobile-bearing total knee arthroplasty (TKA), the femoral component can theoretically slide forward resulting in a more anterior contact point, causing pain due to impingement. A lower lever arm of the extensor apparatus can also attribute to higher patella pressures and pain. The goal of this study was to determine the contact point in a cohort of mobile- and fixed-bearing TKAs, to determine whether the contact point lies more anteriorly in mobile-bearing TKA and to confirm whether this results in anterior knee pain. We used 38 fixed-bearing TKA and 40 mobile-bearing TKA from a randomized trial with straight lateral knee X-rays and measured the contact point. The functional outcome was measured by Knee Society Score at 12 months postoperatively. Pain scores were analysed using a VAS score (0-100 mm) in all patients at rest and when moving. Difficulty at rising up out of a chair was also assessed using a VAS score. The contact point in mobile-bearing TKA was situated at 59.5 % of the AP distance of the tibia and in the fixed-bearing TKA group at 66.1 % (P< 0.05). Patients with mobile- and fixed-bearing TKAs had similar knee scores, pain scores and difficulty in chair rise. No significant correlation was found between contact point and knee pain. The hypothesis of a more anterior contact point in the mobile-bearing cohort was confirmed but no correlation with functional and pain scores in this cohort could be found. The tibiofemoral contact point could not be correlated with a different clinical outcome and higher incidence of anterior knee pain. This study further adds to the knowledge on possible differences between mobile- and fixed-bearing prostheses. Next to that, bad outcomes could not be explained by CP. Case series, Level IV.

Limited rotation of the mobile-bearing in a rotating platform total knee prosthesis.

PubMed

Garling, E H; Kaptein, B L; Nelissen, R G H H; Valstar, E R

2007-01-01

The hypothesis of this study was that the polyethylene bearing in a rotating platform total knee prosthesis shows axial rotation during a step-up motion, thereby facilitating the theoretical advantages of mobile-bearing knee prostheses. We examined 10 patients with rheumatoid arthritis who had a rotating platform total knee arthroplasty (NexGen LPS mobile, Zimmer Inc. Warsaw, USA). Fluoroscopic data was collected during a step-up motion six months postoperatively. A 3D-2D model fitting technique was used to reconstruct the in vivo 3D kinematics. The femoral component showed more axial rotation than the polyethylene mobile-bearing insert compared to the tibia during extension. In eight knees, the femoral component rotated internally with respect to the tibia during extension. In the other two knees the femoral component rotated externally with respect to the tibia. In all 10 patients, the femur showed more axial rotation than the mobile-bearing insert indicating the femoral component was sliding on the polyethylene of the rotating platform during the step-up motion. Possible explanations are a too limited conformity between femoral component and insert, the anterior located pivot location of the investigated rotating platform design, polyethylene on metal impingement and fibrous tissue formation between the mobile-bearing insert and the tibial plateau.

Mobile-bearing total knee arthroplasty: a full traumatic rotation of 180°.

PubMed

Sudanese, Alessandra; Castiello, Emanuela; Affatato, Saverio

2013-06-25

From February 2008 to September 2012 we implanted 204 mobile-bearing knee prostheses in 192 patients. All the prostheses were cemented (both femoral and tibial components), and the patella was not replaced. Only one early complication of the implants (1/204 = 0.004%) occurred after a traumatic event as a full 180° rotation of the mobile-bearing polyethylene insert. A 78-year-old woman presented with swelling and severe pain at her right knee. This traumatic event was the only case among our mobile-bearing insert patients. 
The failed polyethylene inserts were retrieved and studied using a scanning electron microscope (SEM, ZEISS EVO 50 EP, Cambridge, UK) operating at 20 kV. 
Scratching and pitting were found on the UHMWPE insert perpendicular to the machining tracks for the concave surface. SEM micrographs of the insert showed burnishing on the concave surfaces and longitudinal scratches were clearly detectable and well-marked on the analyzed surfaces. 
A traumatic, fully rotating, polyethylene insert is rare and our case is the first report describing a traumatic event with a complete 180 degree rotation mobile-bearing in a total knee prosthesis. 
In the literature few reports discuss clinical outcomes after total knee arthroplasty in patients with Parkinson's disease and they cite mixed results. However, some authors suggest that posterior-stabilized and cruciate-retaining TKA should work well while others prefer cruciate-retaining, condylar constrained kinetics, or hinged devices. Although we did not implant a posterior-stabilized mobile-bearing total knee prosthesis or a constrained prosthesis, we obtained good clinical and radiological results at the 2-year followup.

Early outcome of TKA with a medial pivot fixed-bearing prosthesis is worse than with a PFC mobile-bearing prosthesis.

PubMed

Kim, Young-Hoo; Yoon, Sung-Hwan; Kim, Jun-Shik

2009-02-01

Although the design features of the Medial Pivot fixed-bearing prosthesis reportedly improve kinematics compared with TKAs using fixed-bearings, clinical improvements have not been reported. We asked whether the clinical and radiographic outcomes, ranges of motion of the knee, patient satisfaction, and complication rates would be better in knees with a Medial Pivot fixed-bearing prosthesis than in those with a PFC Sigma mobile-bearing prosthesis. We compared the results of 92 patients who had a Medial Pivot fixed-bearing prosthesis implanted in one knee and a PFC Sigma mobile-bearing prosthesis implanted in the other. There were 85 women and seven men with a mean age of 69.5 years (range, 55-81 years). The minimum followup was 2 years (mean, 2.6 years; range, 2-3 years). The patients were assessed clinically and radiographically using the rating systems of the Hospital for Special Surgery and the Knee Society at 3 months, 1 year, and annually thereafter. Contrary to expectations, we found worse early clinical outcomes, smaller ranges of knee motion, less patient satisfaction, and a higher complication rate for the Medial Pivot fixed-bearing prosthesis than for the PFC Sigma mobile-bearing prosthesis. Level I, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Changes in the three-dimensional load-bearing axis after mobile-bearing total knee arthroplasty.

PubMed

Ishii, Yoshinori; Noguchi, Hideo; Sato, Junko; Ezawa, Nobukazu; Toyabe, Shin-Ichi

2016-07-01

The purpose of this study was to assess changes in the three-dimensional (3D) load-bearing mechanical axis (LBMA) preoperatively and at 3 weeks and more than 1-year follow-up after total knee arthroplasty (TKA), and effects of the degree of constraint in the anteroposterior (AP) direction because of the retention of the posterior cruciate ligament (PCL) and the implant design on the changes in LBMA. We evaluated 157 knees from 131 patients, including 79 knees that received meniscal-bearing-type (PCL-retaining) and 78 knees that received rotating-platform-type (PCL-substituting) prostheses. Quantitative 3D computed tomography was used to assess changes in the location of the pre- and postoperative LBMA at the tibial plateau level. Changes in the 3D axis were mainly found from medial to lateral and posterior to anterior in both implant designs with no significant differences. Change in the mediolateral (ML) direction was improved soon after TKA, but change in the AP direction improved more gradually over time. The different constraints in the AP direction because of the retention of the PCL and different implant designs did not affect the changes in the LBMA. The LBMA in the AP direction more than 1 year postoperatively, as well as the LBMA in the ML direction at 3 weeks, appears to shift toward the location found in normal knees after TKA, regardless of the type of prosthetic constraint. These changes may be an important factor that influences the periarticular knee bone mineral density which load bearing may be related to. Level II, Prognostic study.

Outcome of Unicompartmental Knee Arthroplasty: A Systematic Review of Comparative Studies between Fixed and Mobile Bearings Focusing on Complications

PubMed Central

Ko, Young-Bong; Gujarathi, Manan Ramesh

2015-01-01

The purpose of this systematic review is to collate results of studies comparing fixed and mobile bearing unicompartmental knee arthroplasty (UKA), focusing on complications and timing for reoperations. Out of 723 results derived from PubMed, EMBASE and Cochrane database search engines on bearings in arthroplasty, 10 studies comparing clinical results of fixed bearings to mobile bearings in UKA were found eligible for analysis. The reoperation rate was calculated using a novel method such as reoperations per hundred component years, and the causes of specific reoperations were investigated. The overall reoperation rate per hundred component years was similar between the mobile bearings (1.392) and fixed bearings (1.377); however, mobile bearings were more susceptible to reoperations in cases with aseptic loosening (0.393>0.255), progression of arthritis (0.428>0.357) and implant dislocation (0.286>0). The overall incidence of complications is similar for fixed and mobile bearing designs in UKA. The discussion on complications presented above may assist surgeons in their choice of bearing design. PMID:26389066

Analysis of Impingement between Patella Bone and Bearing Post in Cruciate-Substituting High-Flexion Total Knee Arthroplasty

PubMed Central

Chon, Jegyun; Shin, Sangyeop; Jang, Gunil; Jeon, Taehyeon

2016-01-01

Background We investigated the causes of impingement between the patella bone and the bearing post during high flexion in cruciate-substituting total knee arthroplasty and proposed a treatment strategy. Methods This prospective cohort study included 218 cases that had undergone cruciate-substituting total knee arthroplasty from February 2014 to January 2015; a single surgeon performed the operation using the same method without patellar resurfacing in all patients. Results In these patients, the occurrence of impingement was determined by performing more than 120° high knee flexion after inserting a bearing perioperatively. The incidence of impingement was significantly associated with bearing design, femoral implant size, patella bone length, and patella inferior pole angle (p < 0.05). The impingement was resolved by resection of the lower articular side of the patella bone. Conclusions In the cruciate-substituting high-flexion total knee arthroplasty, impingement between the patella bone and bearing post was more common in patients with mobile bearing, small-size femoral component, and a long patella or a large inferior pole angle. In cases of intraoperative impingement between the patella bone and the bearing post, resection in the lower portion of the patella prevented impingement of the bearing with soft tissue or the patella by widening the space between the patella and the bearing post, which in turn prevented postoperative reduction in range of motion. PMID:27247740

Analysis of Impingement between Patella Bone and Bearing Post in Cruciate-Substituting High-Flexion Total Knee Arthroplasty.

PubMed

Chon, Jegyun; Lee, Bongju; Shin, Sangyeop; Jang, Gunil; Jeon, Taehyeon

2016-06-01

We investigated the causes of impingement between the patella bone and the bearing post during high flexion in cruciate-substituting total knee arthroplasty and proposed a treatment strategy. This prospective cohort study included 218 cases that had undergone cruciate-substituting total knee arthroplasty from February 2014 to January 2015; a single surgeon performed the operation using the same method without patellar resurfacing in all patients. In these patients, the occurrence of impingement was determined by performing more than 120° high knee flexion after inserting a bearing perioperatively. The incidence of impingement was significantly associated with bearing design, femoral implant size, patella bone length, and patella inferior pole angle (p < 0.05). The impingement was resolved by resection of the lower articular side of the patella bone. In the cruciate-substituting high-flexion total knee arthroplasty, impingement between the patella bone and bearing post was more common in patients with mobile bearing, small-size femoral component, and a long patella or a large inferior pole angle. In cases of intraoperative impingement between the patella bone and the bearing post, resection in the lower portion of the patella prevented impingement of the bearing with soft tissue or the patella by widening the space between the patella and the bearing post, which in turn prevented postoperative reduction in range of motion.

Active Flexion in Weight Bearing Better Correlates with Functional Outcomes of Total Knee Arthroplasty than Passive Flexion.

PubMed

Song, Young Dong; Jain, Nimash; Kang, Yeon Gwi; Kim, Tae Yune; Kim, Tae Kyun

2016-06-01

Correlations between maximum flexion and functional outcomes in total knee arthroplasty (TKA) patients are reportedly weak. We investigated whether there are differences between passive maximum flexion in nonweight bearing and other types of maximum flexion and whether the type of maximum flexion correlates with functional outcomes. A total of 210 patients (359 knees) underwent preoperative evaluation and postoperative follow-up evaluations (6, 12, and 24 months) for the assessment of clinical outcomes including maximum knee flexion. Maximum flexion was measured under five conditions: passive nonweight bearing, passive weight bearing, active nonweight bearing, and active weight bearing with or without arm support. Data were analyzed for relationships between passive maximum flexion in nonweight bearing by Pearson correlation analyses, and a variance comparison between measurement techniques via paired t test. We observed substantial differences between passive maximum flexion in nonweight bearing and the other four maximum flexion types. At all time points, passive maximum flexion in nonweight bearing correlated poorly with active maximum flexion in weight bearing with or without arm support. Active maximum flexion in weight bearing better correlated with functional outcomes than the other maximum flexion types. Our study suggests active maximum flexion in weight bearing should be reported together with passive maximum flexion in nonweight bearing in research on the knee motion arc after TKA.

Active Flexion in Weight Bearing Better Correlates with Functional Outcomes of Total Knee Arthroplasty than Passive Flexion

PubMed Central

Song, Young Dong; Jain, Nimash; Kang, Yeon Gwi; Kim, Tae Yune

2016-01-01

Purpose Correlations between maximum flexion and functional outcomes in total knee arthroplasty (TKA) patients are reportedly weak. We investigated whether there are differences between passive maximum flexion in nonweight bearing and other types of maximum flexion and whether the type of maximum flexion correlates with functional outcomes. Materials and Methods A total of 210 patients (359 knees) underwent preoperative evaluation and postoperative follow-up evaluations (6, 12, and 24 months) for the assessment of clinical outcomes including maximum knee flexion. Maximum flexion was measured under five conditions: passive nonweight bearing, passive weight bearing, active nonweight bearing, and active weight bearing with or without arm support. Data were analyzed for relationships between passive maximum flexion in nonweight bearing by Pearson correlation analyses, and a variance comparison between measurement techniques via paired t test. Results We observed substantial differences between passive maximum flexion in nonweight bearing and the other four maximum flexion types. At all time points, passive maximum flexion in nonweight bearing correlated poorly with active maximum flexion in weight bearing with or without arm support. Active maximum flexion in weight bearing better correlated with functional outcomes than the other maximum flexion types. Conclusions Our study suggests active maximum flexion in weight bearing should be reported together with passive maximum flexion in nonweight bearing in research on the knee motion arc after TKA. PMID:27274468

Early outcomes of twin-peg mobile-bearing unicompartmental knee arthroplasty compared with primary total knee arthroplasty.

PubMed

Lum, Z C; Lombardi, A V; Hurst, J M; Morris, M J; Adams, J B; Berend, K R

2016-10-01

Since redesign of the Oxford phase III mobile-bearing unicompartmental knee arthroplasty (UKA) femoral component to a twin-peg design, there has not been a direct comparison to total knee arthroplasty (TKA). Thus, we explored differences between the two cohorts. A total of 168 patients (201 knees) underwent medial UKA with the Oxford Partial Knee Twin-Peg. These patients were compared with a randomly selected group of 177 patients (189 knees) with primary Vanguard TKA. Patient demographics, Knee Society (KS) scores and range of movement (ROM) were compared between the two cohorts. Additionally, revision, re-operation and manipulation under anaesthesia rates were analysed. The mean follow-up for UKA and TKA groups was 5.4 and 5.5 years, respectively. Six TKA (3.2%) versus three UKAs (1.5%) were revised which was not significant (p = 0.269). Manipulation was more frequent after TKA (16; 8.5%) versus none in the UKA group (p < 0.001). UKA patients had higher post-operative KS function scores versus TKA patients (78 versus 66, p < 0.001) with a trend toward greater improvement, but there was no difference in ROM and KS clinical improvement (p = 0.382 and 0.420, respectively). We found fewer manipulations, and higher functional outcomes for patients treated with medial mobile-bearing UKA compared with TKA. TKA had twice the revision rate as UKA although this did not reach statistical significance with the numbers available. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):28-33. ©2016 Berend et al.

Patella position is not a determinant for anterior knee pain 10 years after balanced gap total knee arthroplasty.

PubMed

van Houten, Albert H; Heesterbeek, Petra J C; Wymenga, Ate B

2016-08-01

Incidence of anterior knee pain after total knee arthroplasty (TKA) is reported to be between 4 and 49 %. The incidence of AKP at long-term follow-up and possible determinants after cruciate cruciate-retaining TKA were investigated. A 10-year follow-up of a cohort of 55 patients (63 TKAs), who received the balanSys™ cruciate-retaining total knee system (Mathys Ltd, Bettlach, Switzerland) between 1999 and 2002, was performed. Patients had undergone the balanced gap technique, with either a fixed bearing or an AP-glide bearing. Standardised diagnostic questions regarding AKP were collected and categorised into two groups: those with and without AKP. The lateral patellar tilt, patellar displacement measurement and modified Insall-Salvati ratio were used for patella position evaluation on skyline radiographs. The Knee Society Score (KSS), the Knee Osteoarthritis Outcome Score (KOOS) and Numerical Rating Scales (NRS) for pain and satisfaction were obtained at follow-up. Sixteen patients in the study population experienced AKP. Incidence of AKP (fixed bearing 13/44; AP-glide bearing baring 3/17) was not dependent on type of insert (n.s.). There were no statistical differences in patella position and tibiofemoral contact point between the AKP group and the no AKP group (n.s.). KSS, KOOS, NRS-pain and NRS-satisfaction were significantly lower for the patients with AKP (all p < 0.05). Twenty-six percentage of the patients experienced AKP 10 years after balanced gap TKA. Postoperative patella positioning was not found to be a determinant for anterior knee pain after TKA. However, patellar displacement does not seem completely favourable. Moreover, type of bearing was not found a determinant for AKP at long-term follow-up. Lower quality prospective cohort study (<80 % follow-up, patients enrolled at different time points in disease), Level II.

Polyethylene damage and deformation on fixed-bearing, non-conforming unicondylar knee replacements corresponding to progressive changes in alignment and fixation.

PubMed

Harman, Melinda K; Schmitt, Sabine; Rössing, Sven; Banks, Scott A; Sharf, Hans-Peter; Viceconti, Marco; Hodge, W Andrew

2010-07-01

Deviations from nominal alignment of unicondylar knee replacements impact knee biomechanics, including the load and stress distribution at the articular contact surfaces. This study characterizes relationships between the biomechanical environment, distinguished by progressive changes in alignment and fixation, and articular damage and deformation in a consecutive series of retrieved unicondylar knee replacements. Twenty seven fixed-bearing, non-conforming unicondylar knee replacements of one design were retrieved after 2 to 13 years of in vivo function. The in vivo biomechanical environment was characterized by grading component migration measured from full-length radiographs and grading component fixation based on intraoperative manual palpation. Articular damage patterns and linear deformation on the polyethylene inserts were measured using optical photogrammetry and contact point digitization. Articular damage patterns and surface deformation on the explanted polyethylene inserts corresponded to progressive changes in component alignment and fixation. Component migration produced higher deformation rates, whereas loosening contributed to larger damage areas but lower deformation rates. Migration and loosening of the femoral component, but not the tibial component, were factors contributing to large regions of abrasion concentrated on the articular periphery. Classifying component migration and fixation at revision proved useful for distinguishing common biomechanical conditions associated with the varied polyethylene damage patterns and linear deformation for this fixed-bearing, non-conforming design. Pre-clinical evaluations of unicondylar knee replacements that are capable of reproducing variations in clinical alignment and predicting the observed wear mechanisms are necessary to better understand the impact of knee biomechanics and design on unicondylar knee replacement longevity. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Fixed and mobile-bearing total ankle prostheses: Effect on tibial bone strain.

PubMed

Terrier, Alexandre; Fernandes, Caroline Sieger; Guillemin, Maïka; Crevoisier, Xavier

2017-10-01

Total ankle replacement is associated to a high revision rate. To improve implant survival, the potential advantage of prostheses with fixed bearing compared to mobile bearing is unclear. The objective of this study was to test the hypothesis that fixed and mobile bearing prostheses are associated with different biomechanical quantities typically associated to implant failure. With a validated finite element model, we compared three cases: a prosthesis with a fixed bearing, a prosthesis with a mobile bearing in a centered position, and a prosthesis with mobile bearing in an eccentric position. Both prostheses were obtained from the same manufacturer. They were tested on seven tibias with maximum axial compression force during walking. We tested the hypothesis that there was a difference of bone strain, bone-implant interfacial stress, and bone support between the three cases. We also evaluated, for the three cases, the correlations between bone support, bone strain and bone-implant interfacial stress. There were no statistically significant differences between the three cases. Overall, bone support was mainly trabecular, and less effective in the posterior side. Bone strain and bone-implant interfacial stress were strongly correlated to bone support. Even if slight differences are observed between fixed and mobile bearing, it is not enough to put forward the superiority of one of these implants regarding their reaction to axial compression. When associated to the published clinical results, our study provides no argument to warn surgeons against the use of two-components fixed bearing implants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nontraumatic tibial polyethylene insert cone fracture in mobile-bearing posterior-stabilized total knee arthroplasty.

PubMed

Tanikake, Yohei; Hayashi, Koji; Ogawa, Munehiro; Inagaki, Yusuke; Kawate, Kenji; Tomita, Tetsuya; Tanaka, Yasuhito

2016-12-01

A 72-year-old male patient underwent mobile-bearing posterior-stabilized total knee arthroplasty for osteoarthritis. He experienced a nontraumatic polyethylene tibial insert cone fracture 27 months after surgery. Scanning electron microscopy of the fracture surface of the tibial insert cone suggested progress of ductile breaking from the posterior toward the anterior of the cone due to repeated longitudinal bending stress, leading to fatigue breaking at the anterior side of the cone, followed by the tibial insert cone fracture at the anterior side of the cone, resulting in fracture at the base of the cone. This analysis shows the risk of tibial insert cone fracture due to longitudinal stress in mobile-bearing posterior-stabilized total knee arthroplasty in which an insert is designed to highly conform to the femoral component.

3D kinematics of mobile-bearing total knee arthroplasty using X-ray fluoroscopy.

PubMed

Yamazaki, Takaharu; Futai, Kazuma; Tomita, Tetsuya; Sato, Yoshinobu; Yoshikawa, Hideki; Tamura, Shinichi; Sugamoto, Kazuomi

2015-04-01

Total knee arthroplasty (TKA) 3D kinematic analysis requires 2D/3D image registration of X-ray fluoroscopic images and a computer-aided design (CAD) model of the knee implant. However, these techniques cannot provide information on the radiolucent polyethylene insert, since the insert silhouette does not appear clearly in X-ray images. Therefore, it is difficult to obtain the 3D kinematics of the polyethylene insert, particularly the mobile-bearing insert. A technique for 3D kinematic analysis of a mobile-bearing insert used in TKA was developed using X-ray fluoroscopy. The method was tested and a clinical application was evaluated. Tantalum beads and a CAD model of the mobile-bearing TKA insert are used for 3D pose estimation of the mobile-bearing insert used in TKA using X-ray fluoroscopy. The insert model was created using four identical tantalum beads precisely located at known positions in a polyethylene insert using a specially designed insertion device. Finally, the 3D pose of the insert model was estimated using a feature-based 2D/3D registration technique, using the silhouette of beads in fluoroscopic images and the corresponding CAD insert model. In vitro testing for the repeatability of the positioning of the tantalum beads and computer simulations for 3D pose estimation of the mobile-bearing insert were performed. The pose estimation accuracy achieved was sufficient for analyzing mobile-bearing TKA kinematics (RMS error: within 1.0 mm and 1.0°, except for medial-lateral translation). In a clinical application, nine patients with mobile-bearing TKA were investigated and analyzed with respect to a deep knee bending motion. A 3D kinematic analysis technique was developed that enables accurate quantitative evaluation of mobile-bearing TKA kinematics. This method may be useful for improving implant design and optimizing TKA surgical techniques.

Parametric analysis of electromechanical and fatigue performance of total knee replacement bearing with embedded piezoelectric transducers.

PubMed

Safaei, Mohsen; Meneghini, R Michael; Anton, Steven R

2017-09-01

Total knee arthroplasty (TKA) is a common procedure in the United States; it has been estimated that about 4 million people are currently living with primary knee replacement in this country. Despite huge improvements in material properties, implant design, and surgical techniques, some implants fail a few years after surgery. A lack of information about in vivo kinetics of the knee prevents the establishment of a correlated intra- and postoperative loading pattern in knee implants. In this study, a conceptual design of an ultra high molecular weight (UHMW) knee bearing with embedded piezoelectric transducers is proposed, which is able to measure the reaction forces from knee motion as well as harvest energy to power embedded electronics. A simplified geometry consisting of a disk of UHMW with a single embedded piezoelectric ceramic is used in this work to study the general parametric trends of an instrumented knee bearing. A combined finite element and electromechanical modeling framework is employed to investigate the fatigue behavior of the instrumented bearing and the electromechanical performance of the embedded piezoelectric. The model is validated through experimental testing and utilized for further parametric studies. Parametric studies consist of the investigation of the effects of several dimensional and piezoelectric material parameters on the durability of the bearing and electrical output of the transducers. Among all the parameters, it is shown that adding large fillet radii results in noticeable improvement in the fatigue life of the bearing. Additionally, the design is highly sensitive to the depth of piezoelectric pocket. Finally, using PZT-5H piezoceramics, higher voltage and slightly enhanced fatigue life is achieved.

Parametric analysis of electromechanical and fatigue performance of total knee replacement bearing with embedded piezoelectric transducers

NASA Astrophysics Data System (ADS)

Safaei, Mohsen; Meneghini, R. Michael; Anton, Steven R.

2017-09-01

Total knee arthroplasty is a common procedure in the United States; it has been estimated that about 4 million people are currently living with primary knee replacement in this country. Despite huge improvements in material properties, implant design, and surgical techniques, some implants fail a few years after surgery. A lack of information about in vivo kinetics of the knee prevents the establishment of a correlated intra- and postoperative loading pattern in knee implants. In this study, a conceptual design of an ultra high molecular weight (UHMW) knee bearing with embedded piezoelectric transducers is proposed, which is able to measure the reaction forces from knee motion as well as harvest energy to power embedded electronics. A simplified geometry consisting of a disk of UHMW with a single embedded piezoelectric ceramic is used in this work to study the general parametric trends of an instrumented knee bearing. A combined finite element and electromechanical modeling framework is employed to investigate the fatigue behavior of the instrumented bearing and the electromechanical performance of the embedded piezoelectric. The model is validated through experimental testing and utilized for further parametric studies. Parametric studies consist of the investigation of the effects of several dimensional and piezoelectric material parameters on the durability of the bearing and electrical output of the transducers. Among all the parameters, it is shown that adding large fillet radii results in noticeable improvement in the fatigue life of the bearing. Additionally, the design is highly sensitive to the depth of piezoelectric pocket. Finally, using PZT-5H piezoceramics, higher voltage and slightly enhanced fatigue life is achieved.

Comparison of the low contact stress and press fit condylar rotating-platform mobile-bearing prostheses in total knee arthroplasty: a prospective randomized study.

PubMed

Kim, Young-Hoo; Kim, Jun-Shik; Park, Jang-Won; Joo, Jong-Hwan

2011-06-01

To our knowledge, no study to date has compared the clinical results of posterior cruciate-sacrificing mobile-bearing total knee replacements with those of posterior-stabilized mobile-bearing total knee replacements in the same patients. The purpose of the present study was to compare the clinical and radiographic results of these two designs. We hypothesized that the results would be better for knees treated with the posterior-stabilized mobile-bearing prosthesis. The present study consisted of a consecutive series of 107 female patients (mean age, 66.8 years) who underwent bilateral simultaneous total knee arthroplasty at the same surgical setting. All of these patients received a posterior cruciate-sacrificing mobile-bearing prosthesis in one knee and a posterior-stabilized mobile-bearing prosthesis in the contralateral knee. At the time of each follow-up (mean, 7.4 years; range, seven to 7.6 years), the patients were assessed clinically. The mean postoperative Knee Society knee score (96 compared with 97 points) and Hospital for Special Surgery knee score (93 compared with 94 points) were similar between the two groups. At the time of the latest follow-up, the average range of motion was 127.7° (range, 70° to 150°) in the knees with a posterior cruciate-sacrificing mobile-bearing prosthesis and 132.4° (range, 90° to 150°) in the knees with a posterior-stabilized mobile-bearing prosthesis. With a margin of error of the manual measurement of 5°, this difference was not significant. The estimated survival rate was 97.2% (95% confidence interval, 91% to 99%) at seven years in the posterior-cruciate sacrificing mobile-bearing prosthesis group and 98.1% (95% confidence interval, 92% to 99%) at seven years in the posterior-stabilized mobile-bearing prosthesis group. After a minimum duration of follow-up of seven years, we found no significant differences between the two groups with regard to the clinical and radiographic results, including knee range of motion.

Short-Term Results of Total Knee Arthroplasty with Anterior-Posterior Glide LCS Mobile-Bearing System

PubMed Central

Kim, Kyung Taek; Kang, Min Soo; Lim, Young Hoon; Park, Jin Woo

2014-01-01

Purpose To evaluate the clinical and radiological results of total knee arthroplasty (TKA) using the anterior-posterior glide (APG) low contact stress (LCS) mobile-bearing system. Materials and Methods We evaluated 130 knees in 117 patients who had undergone TKA with APG LCS mobile-bearing system between September 2005 and July 2007 and could be followed over 5 years. The mean follow-up period was 68 months. The clinical and radiological results were evaluated using the American Knee Society Scoring System, Oxford knee score and the American Knee Society Roentgenographic Evaluation and Scoring System. And we analyzed short-term postoperative complications. Results The average range of motion of the knee joint was 107.9° (range, 70° to 135°) preoperatively and 125.2° (range, 90° to 135°) at the last follow-up. The average knee and functional scores were improved from 39.1 and 42.0 to 71.2 and 75.6, respectively, between the preoperative and last follow-up evaluation. The Oxford knee score was decreased from 42.9 preoperatively to 23.1 at the last follow-up. The femoro-tibial angle (anatomical axis) changed from 10.1° varus preoperatively to 3.3° valgus at the last follow-up. Radiolucency was observed in 14% of all cases. There were 1 case of traumatic dislocation of the polyethylene liner, 1 case of aseptic loosening and 6 cases of posterior instability because of posterior cruciate ligament (PCL) insufficiency. Conclusions TKA with APG LCS mobile-bearing system demonstrated relatively good short-term clinical and radiological results. However, further considerations for posterior instability associated with PCL insufficiency are needed. PMID:25229046

Mobile-bearing knee systems: ultra-high molecular weight polyethylene wear and design issues.

PubMed

Greenwald, A Seth; Heim, Christine S

2005-01-01

In June 2004, the U.S. Food and Drug Administration Orthopaedic Advisory Panel recommended the reclassification of mobile-bearing knee systems for general use. This reflects the increasing use of mobile-bearing knee systems internationally, which is currently limited in the United States by regulatory requirement. Mobile-bearing knee systems are distinguished from conventional, fixed-plateau systems in that they allow dual-surface articulation between an ultra-high molecular weight polyethylene insert and metallic femoral and tibial tray components. Their in vivo success is dependent on patient selection, design, and material choice, as well as surgical precision during implantation. Laboratory and clinical experience extending over 25 years with individual systems suggests that mobile-bearing knee systems represent a viable treatment option for patients with knee arthrosis.

The Incidence and Short Term Functional Effect of Partial PCL Release in Fixed and Mobile Bearing PCL Retaining TKA.

PubMed

Schwarzkopf, Ran; Woolwine, Spencer; Josephs, Lee; Scott, Richard D

2015-12-01

Posterior cruciate ligament (PCL) release may be required to balance the flexion gap in PCL retaining TKA. This study examines the incidence and functional consequences of PCL release in both fixed and mobile bearing TKA. A consecutive series of 1388 TKAs with 1014 fixed bearing, and 374 mobile bearing implants were reviewed for prevalence of partial PCL release, restoration of potential flexion and objective knee stability at minimum one-year follow-up. Patients receiving mobile bearing inserts were more likely to need partial PCL release (42% versus 17.5%). The occurrence of partial PCL release did not have a significant impact on knee range of motion and subjective knee stability. The need for a partial PCL release appears to be greater in mobile than in fixed bearing. Knees that required a release in both groups demonstrated no difference in restoration of flexion compared with unreleased knees and no adverse effects on flexion stability. Copyright © 2015 Elsevier Inc. All rights reserved.

Single-Surgeon Experience and Complications of a Fixed-Bearing Total Ankle Arthroplasty.

PubMed

Pangrazzi, Garett J; Baker, Erin A; Shaheen, Phillip J; Okeagu, Chikezie N; Fortin, Paul T

2018-01-01

Total ankle arthroplasty (TAA) has historically resulted in inferior survivorship rates compared with total hip and knee arthroplasty, because of technical issues unique to ankle anatomy. In this study, a single-surgeon series of intra- and postoperative complications as well as resultant reoperations/revisions of the Tornier Salto Talaris, a fixed-bearing TAA prosthesis, were reviewed. Medical records from index procedure to latest follow-up of primary TAA were reviewed. Complications were categorized according to the Glazebrook classification; additional complications were documented. Concurrent procedures were recorded, and radiographs were analyzed for alignment, subsidence, and cyst formation. Time to complication onset and learning curve analyses were performed. One hundred four Salto Talaris TAA prostheses (96 patients), with an average follow-up of 46 months, were included. Thirty-five complications were identified in 32 ankles with a 34% complication rate, resulting in 11 reoperations (5 TAA revisions). Technical error (n = 12), wound healing (n = 9), and aseptic loosening (n = 4) were the most common complications, and there were no statistically significant differences in demographics or follow-up duration between cases with versus without complications. In both the cohorts with and without complications, there were moderate, negative correlations between radiographically observed keel osteopenia and lucency (ρ = -0.548, P = .00125, and ρ = -0.416, P = .000303, respectively); also, in the complication cohort, a weak, positive correlation between subsidence and lucency (ρ = 0.357, P = .0450) was found. Salto Talaris TAA survivorship and reoperation rates in our series were comparable with previous reports, using either the same or similar mobile-bearing prostheses; new information regarding complication, radiographic, and learning curve analyses was presented. Level IV, retrospective case series.

Evaluation of total knee mechanics using a crouching simulator with a synthetic knee substitute.

PubMed

Lowry, Michael; Rosenbaum, Heather; Walker, Peter S

2016-05-01

Mechanical evaluation of total knees is frequently required for aspects such as wear, strength, kinematics, contact areas, and force transmission. In order to carry out such tests, we developed a crouching simulator, based on the Oxford-type machine, with novel features including a synthetic knee including ligaments. The instrumentation and data processing methods enabled the determination of contact area locations and interface forces and moments, for a full flexion-extension cycle. To demonstrate the use of the simulator, we carried out a comparison of two different total knee designs, cruciate retaining and substituting. The first part of the study describes the simulator design and the methodology for testing the knees without requiring cadaveric knee specimens. The degrees of freedom of the anatomic hip and ankle joints were reproduced. Flexion-extension was obtained by changing quadriceps length, while variable hamstring forces were applied using springs. The knee joint was represented by three-dimensional printed blocks on to which the total knee components were fixed. Pretensioned elastomeric bands of realistic stiffnesses passed through holes in the block at anatomical locations to represent ligaments. Motion capture of the knees during flexion, together with laser scanning and computer modeling, was used to reconstruct contact areas on the bearing surfaces. A method was also developed for measuring tibial component interface forces and moments as a comparative assessment of fixation. The method involved interposing Tekscan pads at locations on the interface. Overall, the crouching machine and the methodology could be used for many different mechanical measurements of total knee designs, adapted especially for comparative or parametric studies. © IMechE 2016.

The largest survivorship and clinical outcomes study of the fixed bearing Stryker Triathlon Partial Knee Replacement - A multi-surgeon, single centre cohort study with a minimum of two years of follow-up.

PubMed

Middleton, S W F; Schranz, P J; Mandalia, V I; Toms, A D

2018-05-03

The surgical management of isolated medial compartment degenerative disease of the knee causes debate. Unicompartmental arthroplasty options include fixed and mobile bearing implant designs with fixed bearing becoming increasingly popular. We present the largest cohort of a fixed bearing single radius design, Stryker Triathlon Partial Knee Replacement (PKR). We prospectively collected demographic data and patient reported outcome measures (PROMs) on our cohort of PKR implants since its adoption in our unit, 2009 until March 2015. A total of 129 implants in 115 patients with a mean follow-up of 5.5 years (2.5 to 8.5 years) were included. There were 11 revisions at an average of 1.7 years (0.6-4.1 years), two for infection, two for mal-alignment, five for progression of disease and two for loosening. The survivorship of the implants at five years is 90%. The PKR provides good survivorship at five years and PROM scores that are equal to the largest and most popular comparable implants. There is an associated learning curve with this implant, as there is with all systems and this is reflected in our results. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

Measuring polyethylene wear in total knee arthroplasty by RSA: differences between weight-bearing and non-weight-bearing positioning.

PubMed

van Ijsseldijk, Emiel A; Valstar, Edward R; Stoel, Berend C; de Ridder, Ruud; Nelissen, Rob G H H; Kaptein, Bart L

2014-04-01

Measuring the minimum-joint-space-width (mJSW) in total knee arthroplasty (TKA) in Roentgen stereophotogrammetric analysis (RSA) provides valuable information on polyethylene wear, a leading cause for TKA failure. Most existing studies use non-weight-bearing (NWB) patient positioning. The latter may compromise mJSW measurements due to knee laxity with subsequent non-contact between the TKA components. We investigated the difference in mJSW between weight-bearing (WB) and NWB images and the association with mediolateral (ML) knee stability. At one-year follow-up, 23 TKAs were included from an ongoing RSA study, and ML stability was evaluated. For each examination, the mJSW and femoral-tibial contact locations were measured. A linear regression model was used to analyze the association between the mJSW difference (NWB-WB) with the ML stability and contact locations. The mean mJSW difference was 0.28 mm medially and 0.20 mm laterally. Four TKAs had medium (5-9°) and 19 TKAs had high (<5°) ML stability. A higher mJSW difference was found for TKAs with medium stability (0.36 mm, P = 0.01). In conclusion, mJSW measurements in existing (NWB) RSA studies are influenced by knee laxity, but may still provide information on wear progression based on TKA with high ML stability. A direct comparison of mJSW measurements from WB and NWB data is not possible. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Three-dimensional kinematic estimation of mobile-bearing total knee arthroplasty from x-ray fluoroscopic images

NASA Astrophysics Data System (ADS)

Yamazaki, Takaharu; Futai, Kazuma; Tomita, Tetsuya; Sato, Yoshinobu; Yoshikawa, Hideki; Tamura, Shinichi; Sugamoto, Kazuomi

2011-03-01

To achieve 3D kinematic analysis of total knee arthroplasty (TKA), 2D/3D registration techniques, which use X-ray fluoroscopic images and computer-aided design (CAD) model of the knee implant, have attracted attention in recent years. These techniques could provide information regarding the movement of radiopaque femoral and tibial components but could not provide information of radiolucent polyethylene insert, because the insert silhouette on X-ray image did not appear clearly. Therefore, it was difficult to obtain 3D kinemaitcs of polyethylene insert, particularly mobile-bearing insert that move on the tibial component. This study presents a technique and the accuracy for 3D kinematic analysis of mobile-bearing insert in TKA using X-ray fluoroscopy, and finally performs clinical applications. For a 3D pose estimation technique of the mobile-bearing insert in TKA using X-ray fluoroscopy, tantalum beads and CAD model with its beads are utilized, and the 3D pose of the insert model is estimated using a feature-based 2D/3D registration technique. In order to validate the accuracy of the present technique, experiments including computer simulation test were performed. The results showed the pose estimation accuracy was sufficient for analyzing mobile-bearing TKA kinematics (the RMS error: about 1.0 mm, 1.0 degree). In the clinical applications, seven patients with mobile-bearing TKA in deep knee bending motion were studied and analyzed. Consequently, present technique enables us to better understand mobile-bearing TKA kinematics, and this type of evaluation was thought to be helpful for improving implant design and optimizing TKA surgical techniques.

Multi-ligament instability after early dislocation of a primary total knee replacement - case report.

PubMed

Sisak, Krisztian; Lloyd, John; Fiddian, Nick

2011-01-01

Peripheral nerve blocks have found increased popularity in providing prolonged post-operative analgesia following total knee replacement surgery. They generally provide effective analgesia with fewer complications than epidurals. This report describes an acute low-energy knee dislocation after a well balanced, fixed bearing, cruciate-retaining primary total knee replacement performed under a spinal anaesthetic with combined complimentary femoral and sciatic nerve blocks. The dislocation was not accompanied by neurovascular compromise. Due to the subsequent instability and injury to both collaterals, the posterior cruciate ligament and posterolateral corner structures, the knee was treated with a rotating-hinge revision total knee replacement. The dislocation occurred whilst the peripheral nerve blocks (PNB) were still working. We review our incidence of PNB related complications and conclude that PNB remain a safe and effective analgesia for total knee replacements. However, we advocate that ward staff and patients should be sufficiently educated to ensure that unaided post-operative mobilisation is prevented until such a time that patients have regained complete voluntary muscle control. Copyright © 2009 Elsevier B.V. All rights reserved.

Influence of posterior condylar offset on knee flexion after cruciate-sacrificing mobile-bearing total knee replacement: a prospective analysis of 410 consecutive cases.

PubMed

Bauer, T; Biau, D; Colmar, M; Poux, X; Hardy, P; Lortat-Jacob, A

2010-12-01

The range of motion of the knee joint after Total Knee Replacement (TKR) is a factor of great importance that determines the postoperative function of patients. Much enthusiasm has been recently directed towards the posterior condylar offset with some authors reporting increasing postoperative knee flexion with increasing posterior condylar offset and others who did not report any significant association. Patients undergoing primary total knee replacement were included in a prospective multicentre study and the effect of the posterior condylar offset on the postoperative knee flexion was assessed after adjusting for known influential factors. All knees were implanted by three senior orthopedist surgeons with the same cemented cruciate-sacrificing mobile-bearing implant and with identical surgical technique. Clinical data, active knee flexion and posterior condylar offset were recorded preoperatively and postoperatively at a minimal one year follow-up for all patients. Univariate and multivariate linear models were fitted to select independent predictors of the postoperative knee flexion. Four hundred and ten consecutive total knee replacements (379 patients) were included in the study. The mean preoperative knee flexion was 112°. The mean condylar offset was 28.3mm preoperatively and 29.4mm postoperatively. The mean postoperative knee flexion was 108°. No correlation was found between the posterior condylar offset or the tibial slope and the postoperative knee flexion. The most significant predictive factor for postoperative flexion after posterior-stabilized TKR without PCL retention was the preoperative range of flexion, with a linear effect. Copyright © 2009 Elsevier B.V. All rights reserved.

Clinical and biomechanical assessment of patella resurfacing in total knee arthroplasty.

PubMed

Berti, Lisa; Benedetti, Maria Grazia; Ensini, Andrea; Catani, Fabio; Giannini, Sandro

2006-07-01

Currently there is a limited understanding of the factors influencing range of motion by comparing patellar resurfacing vs non-resurfacing in total knee arthroplasty during activities of daily living. A recent meta-analysis of patellar replacement confirms better outcome with patella resurfacing; however, the result can be influenced by many other factors, such as: component design, surgeon experience, and technical aspects of the surgery. This study compares the biomechanics of the knee in patients after total knee arthroplasty with and without patellar resurfacing during stair climbing. Forty-seven patients with total knee arthroplasty were assessed at the mean follow-up of 24 months. In all of them a posterior stabilised fixed bearing prosthesis (Optetrak PS, Exactech) was implanted. Twenty-six patients were treated without patellar resurfacing and 21 with patellar resurfacing. Clinical evaluations were performed using the International Knee Society and the Hospital for Special Surgery scores. Ten patients with patellar resurfacing and 10 patients without patellar resurfacing were also studied with motion analysis during stair climbing; 10 healthy subjects were studied for statistical comparison. Clinical passive knee flexion, International Knee Society Function and Hospital for Special Surgery scores were significantly higher in the patellar resurfacing group. During stair climbing, active knee joint range of motion during the stance phase was greater in patients with patellar resurfacing. The maximum adduction moment was significantly higher in the group without patellar resurfacing. Patients with patellar resurfacing demonstrated better clinical scores, and kinematic and kinetic data while ascending stairs.

Effects of tibial slope changes in the stability of fixed bearing medial unicompartmental arthroplasty in anterior cruciate ligament deficient knees.

PubMed

Suero, Eduardo M; Citak, Musa; Cross, Michael B; Bosscher, Marianne R F; Ranawat, Anil S; Pearle, Andrew D

2012-08-01

Patients with anterior cruciate ligament (ACL) deficiency may have increased failure rates with UKA as a result of abnormal contact stresses and altered knee kinematics. Variations in the slope of the tibial component in UKA may alter tibiofemoral translation, and affect outcomes. This cadaveric study evaluated tibiofemoral translation during the Lachman and pivot shift tests after changing the slope of a fixed bearing unicondylar tibial component. Sectioning the ACL increased tibiofemoral translation in both the Lachman and pivot shift tests (P<0.05). Tibial slope leveling (decreasing the posterior slope) of the polyethylene insert in a UKA decreases anteroposterior tibiofemoral translation in the sagittal plane to a magnitude similar to that of the intact knee. With 8° of tibial slope leveling, anterior tibial translation during the Lachman test decreased by approximately 5mm. However, no variation in slope altered the pivot shift kinematics in the ACL deficient knees. Copyright © 2011 Elsevier B.V. All rights reserved.

Contact stresses, pressure and area in a fixed-bearing total ankle replacement: a finite element analysis.

PubMed

Martinelli, Nicolo; Baretta, Silvia; Pagano, Jenny; Bianchi, Alberto; Villa, Tomaso; Casaroli, Gloria; Galbusera, Fabio

2017-11-25

Mobile-bearing ankle implants with good clinical results continued to increase the popularity of total ankle arthroplasty to address endstage ankle osteoarthritis preserving joint movement. Alternative solutions used fixed-bearing designs, which increase stability and reduce the risk of bearing dislocation, but with a theoretical increase of contact stresses leading to a higher polyethylene wear. The purpose of this study was to investigate the contact stresses, pressure and area in the polyethylene component of a new total ankle replacement with a fixed-bearing design, using 3D finite element analysis. A three-dimensional finite element model of the Zimmer Trabecular Metal Total Ankle was developed and assembled based on computed tomography images. Three different sizes of the polyethylene insert were modeled, and a finite element analysis was conducted to investigate the contact pressure, the von Mises stresses and the contact area of the polyethylene component during the stance phase of the gait cycle. The peak value of pressure was found in the anterior region of the articulating surface, where it reached 19.8 MPa at 40% of the gait cycle. The average contact pressure during the stance phase was 6.9 MPa. The maximum von Mises stress of 14.1 MPa was reached at 40% of the gait cycle in the anterior section. In the central section, the maximum von Mises stress of 10.8 MPa was reached at 37% of the gait cycle, whereas in the posterior section the maximum stress of 5.4 MPa was reached at the end of the stance phase. The new fixed-bearing total ankle replacement showed a safe mechanical behavior and many clinical advantages. However, advanced models to quantitatively estimate the wear are need. To the light of the clinical advantages, we conclude that the presented prosthesis is a good alternative to the other products present in the market.

Custom-fit total knee arthroplasty: our initial experience with 30 knees.

PubMed

Bonicoli, Enrico; Andreani, Lorenzo; Parchi, Paolo; Piolanti, Nicola; Lisanti, Michele

2014-10-01

We report our initial experience of total knee arthroplasty (TKA) using customized cutting block technology in 30 TKAs from December 2010 to September 2012. Customized blocks were generated for each of the knees using preoperative magnetic resonance imaging of knee and long-leg weight-bearing radiographs. At 30 days, long-leg radiographs were obtained to evaluate the coronal alignment. Twenty-six of the 30 knees had a mechanical axis restored to within 3° of neutral. We conclude that this technology can be safely used in most of the cases of osteoarthritis.

High incidence of loosening of the femoral component in legacy posterior stabilised-flex total knee replacement.

PubMed

Han, H S; Kang, S-B; Yoon, K S

2007-11-01

We have examined the results obtained with 72 NexGen legacy posterior stabilised-flex fixed total knee replacements in 47 patients implanted by a single surgeon between March 2003 and September 2004. Aseptic loosening of the femoral component was found in 27 (38%) of the replacements at a mean follow-up of 32 months (30 to 48) and 15 knees (21%) required revision at a mean of 23 months (11 to 45). We compared the radiologically-loose and revised knees with those which had remained well-fixed to identify the factors which had contributed to this high rate of aseptic loosening. Post-operatively, the mean maximum flexion was 136 degrees (110 degrees to 140 degrees) in the loosened group and 125 degrees (95 degrees to 140 degrees) in the well-fixed group (independent t-test, p = 0.022). Squatting, kneeling, or sitting cross-legged could be achieved by 23 (85%) of the loosened knees, but only 22 (49%) of the well-fixed knees (chi-squared test, p = 0.001). The loosened femoral components were found to migrate into a more flexed position, but no migration was detected in the well-fixed group. These implants allowed a high degree of flexion, but showed a marked rate of early loosening of the femoral component, which was associated with weight-bearing in maximum flexion.

Different intraoperative kinematics with comparable clinical outcomes of ultracongruent and posterior stabilized mobile-bearing total knee arthroplasty.

PubMed

Kim, Tae Woo; Lee, Sang Min; Seong, Sang Cheol; Lee, Sahnghoon; Jang, Jak; Lee, Myung Chul

2016-09-01

There remains no consensus as to whether mobile total knee arthroplasty (TKA) should use a posterior cruciate ligament-sacrificing ultracongruent (UC) or a posterior cruciate ligament-substituting posterior stabilized (PS) prosthesis. The purpose of this study was to assess intraoperative kinematics and clinical outcomes of UC and PS rotating platform mobile-bearing TKA. In this randomized controlled study, mobile UC TKA prostheses (n = 45) were compared with mobile PS TKA prostheses (n = 45) with regard to intraoperative kinematics and clinical outcomes. The passive kinematic study using intraoperative navigation system included anterior/posterior translation, varus/valgus alignment and rotation of femur during flexion. The patients were clinically and radiographically evaluated over a 3-year follow-up. Paradoxical anterior translation of the femur was 10.8 ± 5.2 mm in the UC knee from 0° to 82° of knee flexion and 8.7 ± 3.0 mm in the PS knee from 0° to 70° of knee flexion (p = 0.027). Paradoxical internal rotation of the femur was 5.8° in the UC knees and 9.9° in the PS knees (p = 0.003). But, there was no significant difference between the groups in regard to the coronal alignment. There was no significant difference in the range of motion, KS knee scores, KS function scores, and WOMAC index scores. Despite different intraoperative kinematics between mobile UC and mobile PS TKA, neither design reproduced physiologic knee kinematics and there was no difference in clinical outcomes between the two groups. The clinical relevance of the study is that despite different intraoperative kinematics, UC design can be a considerable alternative to PS design in mobile-bearing TKA in respect of clinical outcomes. II.

Reduced Bearing Excursion After Mobile-Bearing Unicompartmental Knee Arthroplasty is Associated With Poor Functional Outcomes.

PubMed

Wahal, Naman; Gaba, Sahil; Malhotra, Rajesh; Kumar, Vijay; Pegg, Elise C; Pandit, Hemant

2018-02-01

A small proportion of patients with mobile unicompartmental knee arthroplasty (UKA) report poor functional outcomes in spite of optimal component alignment on postoperative radiographs. The purpose of this study is to assess whether there is a correlation between functional outcome and knee kinematics. From a cohort of consecutive cases of 150 Oxford medial UKA, patients with fair/poor functional outcome at 1-year postsurgery (Oxford Knee Score [OKS] < 34, n = 15) were identified and matched for age, gender, preoperative clinical scores, and follow-up period with a cohort of patients with good/excellent outcome (OKS ≥ 34, n = 15). In vivo kinematic assessment was performed using step-up and deep knee bend exercises under fluoroscopic imaging. The fluoroscopic videos were analyzed using MATLAB software to measure the variation in time taken to complete the exercises, patellar tendon angle, and bearing position with knee flexion angle. Mean OKS in the fair/poor group was 29.9 and the mean OKS in the good/excellent group was 41.1. The tibial slope, time taken to complete the exercises, and patellar tendon angle trend over the flexion range were similar in both the groups; however, bearing position and the extent of bearing excursion differed significantly. The total bearing excursion in the OKS < 34 group was significantly smaller than the OKS ≥ 34 group (35%). Furthermore, on average, the bearing was positioned 1.7 mm more posterior on the tibia in the OKS < 34 group. This study provides evidence that abnormal knee kinematics, in particular bearing excursion and positioning, are associated with worse functional outcomes after mobile UKA. Copyright © 2017 Elsevier Inc. All rights reserved.

[Effect of posterior condylar offset on knee flexion after high-flex posterior-stabilized total knee arthroplasty].

PubMed

Zhang, Yu; Liu, Jun; Tian, Meng-qiang; Cheng, Yu; Tian, Zheng-wei; Sun, Zhen-hui; Ma, Xin-long

2010-05-15

To determine the effect of the posterior condylar offset (PCO) on intra- and post-operative knee flexion after total knee arthroplasty (TKA) using a high-flex posterior-stabilized (PS) fixed-bearing prosthesis and to discuss it's importance in femoral prosthesis design. The clinical and radiographic materials of 100 consecutive patients (100 knees) were prospectively studied, including 50 men and 50 women, who had undergone primary NexGen LPS-Flex TKAs for end-stage osteoarthritis. All operations were performed by a single surgeon using the same operative technique between March 2005 and October 2006. Pearson's regression analysis was used to assess the relationship between the difference in the pre- and post-operative PCO on true lateral radiographs and the change in knee range of flexion (ROF) under non-weight-bearing conditions. The decrease of the corrected PCO was (3.4 ± 3.3) mm compared with the preoperative value, the restoration of PCO was better in male than female [female (-5.4 ± 3.1) mm vs. male (-1.5 ± 2.0) mm, P < 0.05]. The difference in the corrected PCO after PS TKA demonstrated significantly correlated with the change in 2 years postoperative ROF in male and female, respectively (P < 0.05). While no statistically correlation was observed in the overall group (P > 0.05). Intraoperatively, the difference in the corrected PCO was significantly correlated with the change in ROF in male, female, and the overall group, respectively (P < 0.05). Restoration of PCO plays an important role in the optimization of knee flexion after high-flex PS TKA. Femoral components based on Caucasian anatomic characteristics could not match the native anatomy of distal femurs of Chinese population especially female Chinese. Rotated resection of distal femur with anterior referencing technique usually leads to a decreased PCO and therefore reduces maximal obtainable flexion. Sexual dimorphism in humans and anatomic variations in various ethnic groups should be seriously

The Mediolateral Excursion of the Meniscal Bearing during Flexion and Extension of the Knee after Medial Mobile-Bearing Unicompartmental Knee Arthroplasty.

PubMed

Lee, Seung-Yup; Bae, Ji-Hoon; Suh, Dong-Won; Kim, Han-Ju; Lim, Hong-Chul

2017-02-01

This mediolateral excursion of the bearing during knee motion is supposed to be caused by external rotation of the tibia during knee extension. However, to our knowledge, there is no published clinical evidence supporting these hypotheses. The current study aimed to evaluate the mediolateral excursion of the bearing during flexion-extension motion of the knee after medial unicompartmental knee arthroplasty (UKA). In 52 knees, varus/valgus (F-VarVal) or rotational position (F-Rot) of the femoral component and relative location of the bearing were measured with the standing anteroposterior and modified axial view, respectively. We adopted the modified axial radiographs that are simple to assess the bearing position in the flexed knee. The modified axial view showed excellent inter- and intraobserver agreements. F-Rot in the modified axial view and CT showed a high agreement in terms of validity (r = 0.98; p  < 0.0001). On average, the bearing showed more medial position in extension than flexion of the knee. No correlation was found between the femoral component positions (F-VarVal and F-Rot) and mediolateral bearing excursion ( p  = 0.68 and 0.80, respectively). In conclusion, coronal location of bearing according to flexion-extension of the knee is not influenced by the coronal and axial alignment of the femoral component. With simple radiographic method, more medial position of the bearing according to flexion-extension of the knee. Our method could be used to assess axial rotation of the femoral component and spin-out phenomenon of the bearing following the medial UKA. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Medium- to Long-Term Results of the Nexgen Legacy Posterior Stabilized Fixed-Bearing Knee Replacement.

PubMed

Arikupurathu, Oommen Mathew; Johnston, Linda; MacInnes, Alasdair; Nicol, Graeme; Nassif, Manhal

2018-06-20

The NexGen legacy posterior stabilized (LPS) prosthesis was introduced in 1997 after many design changes to its predecessor, the Insall-Burstein II prosthesis. However, there have been no reported long-term studies on the performance of this implant. Prospectively, collected data from a local database comprising primary total knee replacements (TKRs) with LPS between 1997 and 2002 was analyzed. All implants were fixed with cement. Patients were followed up at 1, 3, 5, 7, and 10 years, with patient satisfaction, range of movement, and Knee Society score (KSS) assessed. A total of 621 primary TKRs were analyzed with an average follow-up of 11.25 years (9.15-14.55). The mean age was 69.53 years. The mean KSS was 88.97 and mean flexion increased from 88.3 to 103.5 degrees at 10 years. Kaplan-Meier's analysis revealed a survivorship of 96.5% with revision for any reason as the end point and 98.9% if aseptic loosening was the reason for revision at 14 years. This study revealed excellent mid- to long-term results with the NexGen LPS prosthesis. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Mobile bearing medial unicompartmental knee arthroplasty in patients whose lifestyles involve high degrees of knee flexion: A 10-14year follow-up study.

PubMed

Choy, Won Sik; Lee, Kwang Won; Kim, Ha Yong; Kim, Kap Jung; Chun, Young Sub; Yang, Dae Suk

2017-08-01

Because Asian populations have different lifestyles, such as squatting and sitting on the floor, from those of Western populations, it is possible that the clinical results and survival rate of unicompartmental knee arthroplasty (UKA) for Asian patients may be different. This study described outcomes of mobile bearing medial UKA for Korean patients. A total of the 164 knees treated with mobile bearing UKAs in 147 patients (14 males and 133 females) were reviewed. The mean follow-up period was 12.1years (range 10.1-14). The clinical outcomes, such as the Hospital for Special Surgery Knee score, the Oxford Knee Score and the Knee Society rating system, showed statistically significant improvement from pre-operative to final follow-up (P<0.05). A total of 26 UKAs (15.8%) required revision; the most common reason was bearing dislocation. The 95% confidence interval of survival rate at 12years was 84.1%, with revision for any reason as the end point. Minimally invasive mobile bearing UKA in Asian patients who required high degrees of knee flexion showed rapid recovery and good clinical outcome. However, they also showed relatively high rates of bearing dislocation and aseptic loosening. Therefore, mobile bearing UKA should only be performed in patients whose lifestyle involves high flexions after carefully considering these risks and benefits. Copyright © 2017 Elsevier B.V. All rights reserved.

A comparison of clinical- and patient-reported outcomes of the cemented ATTUNE and PFC sigma fixed bearing cruciate sacrificing knee systems in patients who underwent total knee replacement with both prostheses in opposite knees.

PubMed

Carey, Brian W; Harty, James

2018-03-15

The ATTUNE Knee by DePuy Synthes was introduced in 2013. It is designed to provide better range of motion and address patient-reported instability. The PFC Sigma Knee, an earlier prosthesis by DePuy Synthes, is a common knee replacement with a strong clinical track record. Our aim is to compare the outcomes after primary total knee replacement for end-stage knee osteoarthritis of the PFC and ATTUNE knee systems in 21 patients who each have prosthesis in opposite knees using WOMAC, Oxford Knee and SF-12 scores and evaluation of range of motion. A review was carried out on 21 patients who underwent primary total knee replacement with both the ATTUNE and PFC knee systems. These were staged operations performed in the same institution and by the same surgeon. All cases were followed up for a minimum of 6 months. WOMAC, Oxford Knee and SF-12 scores, as well as knee range of motion were recorded preoperatively and at 6 months postoperatively. There was a significant difference in pre- to 6-month post-operative outcomes in PFC and ATTUNE groups with regard to improvement in range of motion (10° ± 8 and 13° ± 11, respectively). There was also a significant improvement in WOMAC scores (PFC group) and Oxford Knee Scores (ATTUNE group) (8.9 ± 7.7 and 12.1 ± 8.4, respectively). There was a significant improvement in SF-12 Score in both groups (10.1 ± 9.3 for PFC and 15.8 ± 13.3 for ATTUNE). The minimum clinically important difference (MCID) in scoring systems at 6 months was reached by 6 patients in the PFC group and 12 in the ATTUNE group. A significant difference was demonstrated in clinical outcome at 6 months postoperatively between PFC and ATTUNE knee systems in patients who underwent total knee arthroplasty with both prostheses. Superior results were recorded for the ATTUNE knee system.

Intramedullary knee arthrodesis as a salvage procedure after failed total knee replacement.

PubMed

Panagiotopoulos, E; Kouzelis, A; Matzaroglou, Ch; Saridis, A; Lambiris, E

2006-12-01

Septic and aseptic loosening with or without extensive bone loss after total knee replacement are the most common indications for knee fusion. Both external fixation and intramedullary nailing can be used for the treatment, though the latter appears to be the method of choice for most patients. Nine patients were treated after a total knee replacement failure using intramedullary nailing. A long intramedullary nail with a proximal interlocking screw was used in five cases, and a customised nail was used in four cases. Successful fusion occurred in eight of nine patients (89%). Average time for the joint union was 6.5 months, and average operative blood loss was 860 ml. In two patients, iliac crest and patellar bone graft were also used. In conclusion, intramedullary nailing can give excellent results in achieving knee fusion after a failed knee replacement as it allows early weight bearing and at the same time offers stability, pain relief, and a high rate of union, even though the surgical technique is demanding.

Sagittal tibiotalar translation and clinical outcomes in mobile and fixed-bearing total ankle replacement.

PubMed

Usuelli, Federico G; Manzi, Luigi; Brusaferri, Giovanni; Neher, Robert E; Guelfi, Matteo; Maccario, Camilla

2017-06-01

Sagittal implant malalignment after total ankle replacement (TAR) has been considered to be a possible cause for premature implant failure. In a prior study, the change over time of the tibiotalar ratio (T-T ratio), which is the ratio between the posterior longitudinal talar length and the full longitudinal talar length, was assessed in 66 TARs where an unconstrained, mobile-bearing implant was implanted. The analysis documented an increase in the T-T ratio between 2 and 6 months post-surgery (on average from 34.6% to 37.2%). We hypothesized that this change might have been related to the presence of a mobile-bearing insert. In order to test our hypothesis, we designed a study to compare the translation of the talus in TARs performed with an unconstrained, mobile-bearing implant (designated the "Mobile ankle") and those performed with a semi-constrained, fixed-bearing implant (designated the "Fixed ankle"). The study included 71 consecutive patients (71 ankles) who underwent TAR with the Mobile ankle and 24 consecutive patients (24 ankles) who received the Fixed ankle from May 2011 to December 2014. Patients were assessed clinically and radiologically preoperatively (T 0 ), at 6 months (T 2 ) and 12 months (T 3 ) post-surgery. There was also a radiological assessment at 2 months post-surgery (T 1 ). The comparison of the T-T ratio between the two implant groups and over time indicated an interaction between time and group, therefore the changes of the T-T ratio over time were affected by the implant type factor (P<0.001). The changes of the postoperative T-T ratio over time were not significant in the Fixed ankle group (35.7±6.7% at T 1 , T 2 , and T 3 ; P=1.0 for each pairwise comparison). In the Mobile ankle group, the T-T ratio at 2 months (34.4±5.5%) was significantly different to the T-T ratio at 6 months (37.0±5.8%; P<0.001; i.e. there was a significant posterior translation of the talus). The AOFAS score increased from preop to 12 months post-surgery in

Custom-fit total knee arthroplasty: our initial experience in 32 knees.

PubMed

Bali, Kamal; Walker, Peter; Bruce, Warwick

2012-06-01

We share our initial experience of total knee arthroplasty (TKA) using customized cutting block technology in 32 TKAs from May 2010 to March 2011. Ten of these patients had prior TKA done on the other side using conventional or navigation-assisted TKA. Customized cutting blocks were generated for each of the knee using preoperative magnetic resonance imaging of knee and long-leg weight-bearing radiographs. At 6 weeks, long-leg radiographs were obtained to evaluate the coronal alignment. There were no adverse intraoperative events. Twenty-nine of the 32 knees had a mechanical axis restored to within 3°° of neutral. Of 10 patients with prior TKA without custom-fit technology, the mean blood loss and the mean skin-to-skin time was found to be lower in knees that had undergone custom-fit TKA. We conclude that this technology can be safely used in most of the cases of osteoarthritis. Copyright © 2012 Elsevier Inc. All rights reserved.

Does circumpatellar electrocautery improve the outcome after total knee replacement?: a prospective, randomised, blinded controlled trial.

PubMed

Baliga, S; McNair, C J; Barnett, K J; MacLeod, J; Humphry, R W; Finlayson, D

2012-09-01

The incidence of anterior knee pain following total knee replacement (TKR) is reported to be as high as 49%. The source of the pain is poorly understood but the soft tissues around the patella have been implicated. In theory circumferential electrocautery denervates the patella thereby reducing efferent pain signals. However, there is mixed evidence that this practice translates into improved outcomes. We aimed to investigate the clinical effect of intra-operative circumpatellar electrocautery in patients undergoing TKR using the LCS mobile bearing or Kinemax fixed bearing TKR. A total of 200 patients were randomised to receive either circumpatellar electrocautery (diathermy) or not (control). Patients were assessed by visual analogue scale (VAS) for anterior knee pain and Oxford knee score (OKS) pre-operatively and three months, six months and one year post-operatively. Patients and assessors were blinded. There were 91 patients in the diathermy group and 94 in the control. The mean VAS improvement at one year was 3.9 in both groups (control; -10 to 6, diathermy; -9 to 8, p < 0.001 in both cases, paired, two-tailed t-test). There was no significant difference in VAS between the groups at any other time. The mean OKS improvement was 17.7 points (0 to 34) in the intervention group and 16.6 (0 to 42) points in the control (p = 0.36). There was no significant difference between the two groups in OKS at any other time. We found no relevant effect of patellar electrocautery on either VAS anterior knee pain or OKS for patients undergoing LCS and Kinemax TKR.

Different Factors Conduct Anterior Knee Pain Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

PubMed

Duan, Guman; Liu, Chang; Lin, Weiwei; Shao, Jiashen; Fu, Kunpeng; Niu, Yingzhen; Wang, Fei

2018-06-01

A systematic review and meta-analysis was performed to investigate the risks associated with anterior knee pain (AKP) following primary total knee arthroplasty (TKA). A computerized search was performed of the following databases: MEDLINE, Embase, and Cochrane Central (published prior to July 2017). A total of 37 studies, which included 1641 cases of AKP and 168,090 TKAs, were included in the meta-analysis. A subgroup analysis revealed that compared with those without the following medical conditions, patients who had an infrapatellar fat pad excision and more than 12 months of follow-up (odds ratio [OR] 12.58, 95% confidence interval [CI] 3.245-48.781) were more likely to have AKP after TKA. Circumpatellar electrocautery (>12 months: OR 0.50, 95% CI 0.326-0.760; ≤12 months: OR 0.59, 95% CI 0.408-0.867) and patellar resurfacing (OR 0.25, 95% CI 0.131-0.485) may decrease the risk of AKP. Other factors, including the prosthesis bearing type (mobile bearing or fixed bearing) and the approach (midvastus compared with the medial parapatellar approach), were not significant risk factors for AKP. The use of strategies such as patellar denervation and patellar resurfacing in primary TKA is recommended because they are safe and result in good clinical outcomes in preventing AKP. Caution should be taken when using an infrapatellar fat pad excision, because there is an increased risk of AKP at long-term follow-up (>12 months). Future studies should investigate these different strategies to confirm the underlying mechanisms and help prevent the occurrence of AKP after TKA. The timing of AKP onset remains unclear and requires further research. Copyright © 2018 Elsevier Inc. All rights reserved.

Mid-term results of lateral unicondylar mobile bearing knee arthroplasty: a multicentre study of 363 cases.

PubMed

Walker, T; Zahn, N; Bruckner, T; Streit, M R; Mohr, G; Aldinger, P R; Clarius, M; Gotterbarm, T

2018-01-01

The aim of this independent multicentre study was to assess the mid-term results of mobile bearing unicondylar knee arthroplasty (UKA) for isolated lateral osteoarthritis of the knee joint. We retrospectively evaluated 363 consecutive, lateral UKAs (346 patients) performed using the Oxford domed lateral prosthesis undertaken in three high-volume knee arthroplasty centres between 2006 and 2014. Mean age of the patients at surgery was 65 years (36 to 88) with a mean final follow-up of 37 months (12 to 93) RESULTS: A total of 36 (10.5%) patients underwent revision surgery, giving a survival rate of 90.1% at three years (95% confidence intervals (CI) 86.1 to 93.1; number at risk: 155) and 85.0% at five years (95% CI 77.9 to 89.9; number at risk: 43). Dislocation of the mobile bearing occurred in 18 patients (5.6%) at three years (95% CI 1.0 to 16.4; number at risk: 154) and in 20 patients (8.5%) at five years (95% CI 1.0 to 27.0; number at risk: 42). There were no significant differences in the dislocation rate between the participating centres or the surgeons. We were not able to identify an effect of each surgeon's learning curve on the dislocation rate of the mobile bearing. The clinical outcome in patients without revision surgery at final follow-up was good to excellent, with a mean Oxford knee score of 40.3 (95% CI 39.4 to 41.2), a mean Tegner activity score of 3.2 (95% CI 3.1 to 3.3) and a mean University of California, Los Angeles score of 5.7 (95% CI 5.5 to 5.9). Our data, which consists of a high number of patients treated with mobile bearing UKA in the lateral compartment, indicates a high revision rate of 15% at five years with dislocation of the mobile bearing being the main reason for implant failure. Despite the good functional and clinical results and the high patient satisfaction in our study group, we therefore discontinued using mobile-bearing lateral UKA in favour of a fixed-bearing component. Cite this article: Bone Joint J 2018;100-B:42-9. ©2018

Quantification of polyethylene degradation in mobile bearing knees: a retrieval analysis of the Anterior-Posterior-Glide (APG) and Rotating Platform (RP) Low Contact Stress (LCS) knee.

PubMed

Kop, Alan M; Swarts, Eric

2007-06-01

Routine qualitative observations of more than 850 polyethylene fixed and mobile bearings at our institution have noted minimal wear of mobile bearings. The APG mobile bearing is the most recent design variant of the LCS knee, allows multi-directional movement at the tibiofemoral articulation, and is posterior cruciate sparing. Even though it is difficult to perform, quantitative wear measurement is important in determining the likely longevity of new arthroplasty devices, and is especially relevant because of increasing numbers of new mobile bearing designs. We analyzed 10 retrieved APG and 7 retrieved RP tibial bearings (De Puy) with a mean implantation period of 33 (9-70) months. We used coordinate-measuring techniques to quantitatively determine linear penetration, and optical and scanning electron microscopy to assess wear mechanisms qualitatively. The mean total volume loss (superior and inferior articulations) of the APG and RP designs was 85 mm((3))/year and 77 mm((3))/year, respectively. Burnishing was the predominant wear mechanism, and to a lesser extent scratching, abrasion and pitting. Multidirectional scratching and abrasion were noted on the APG inserts inferiorly, whereas there was circumferential scratching on the RP inserts. Our short-term results for the APG and RP mobile bearing designs are similar and compare more than favorably with reported values for fixed-bearing designs. However, increased backside wear due to multidirectional movement may predispose the APG design to greater wear in the long term.

Wear Distribution Detection of Knee Joint Prostheses by Means of 3D Optical Scanners

PubMed Central

Affatato, Saverio; Valigi, Maria Cristina; Logozzo, Silvia

2017-01-01

The objective of this study was to examine total knee polyethylene inserts from in vitro simulation to evaluate and display—using a 3D optical scanner—wear patterns and wear rates of inserts exposed to wear by means of simulators. Various sets of tibial inserts have been reconstructed by using optical scanners. With this in mind, the wear behavior of fixed and mobile bearing polyethylene knee configurations was investigated using a knee wear joint simulator. After the completion of the wear test, the polyethylene menisci were analyzed by an innovative 3D optical scanners in order to evaluate the 3D wear distribution on the prosthesis surface. This study implemented a new procedure for evaluating polyethylene bearings of joint prostheses obtained after in vitro wear tests and the proposed new approach allowed quantification of the contact zone on the geometry of total knee prostheses. The results of the present study showed that mobile TKPs (total knee prosthesis) have lower wear resistance with respect to fixed TKPs. PMID:28772725

[Indications and Borderline Indications for Medial Mobile Bearing Unicondylar Knee Replacement].

PubMed

Walker, T; Streit, M R; Streit, J; Gotterbarm, T; Aldinger, P R

2015-10-01

Beside the possibility of bicondylar knee replacement, patients with isolated anteromedial osteoarthritis also have the possibility of unicondylar knee replacement. Therefore some requirements are essential such as functionally intact cruciate and collateral ligaments, intact cartilage in the lateral compartment and an intraoperative flexion of more than 100°. An instability or contracture of the cruciate or collateral ligaments, a varus deformity more than 15°, a flexion deformity of more than 15°, an intraoperative flexion less than 100° as well as failed upper tibial osteotomy are seen as contraindications. In addition, a rheumatoid arthritis and a full thickness cartilage defect in the central part of the lateral compartment are seen as a contraindication because of the risk of a progression of the disease. With respect to these contraindications, excellent functional outcome and survival rates could be demonstrated in the long term. An expansion of these criteria, especially in patients with an insufficiency of the cruciate ligaments or after failed upper tibial osteotomy should only be done in certain cases after careful assessment of the benefits and risks. These patients should be informed about the lack of long-term results and the higher risk of complications. Quite commonly, the criteria of Kozinn and Scott are used for patient selection. These criteria were originally established for fixed-bearing prosthesis and have no relevance on mobile-bearing prosthesis. Criteria such as age, level of activity, weight, chondrocalcinosis and anterior knee pain have no effect on the clinical outcome or the long-term survival of a mobile-bearing prosthesis. Georg Thieme Verlag KG Stuttgart · New York.

RSA migration of total knee replacements.

PubMed

Pijls, Bart G; Plevier, José W M; Nelissen, Rob G H H

2018-06-01

Purpose - We performed a systematic review and meta-analyses to evaluate the early and long-term migration patterns of tibial components of TKR of all known RSA studies. Methods - Migration pattern was defined as at least 2 postoperative RSA follow-up moments. Maximal total point motion (MTPM) at 6 weeks, 3 months, 6 months, 1 year, 2 years, 5 years, and 10 years were considered. Results - The literature search yielded 1,167 hits of which 53 studies were included, comprising 111 study groups and 2,470 knees. The majority of the early migration occurred in the first 6 months postoperatively followed by a period of stability, i.e., no or very little migration. Cemented and uncemented tibial components had different migration patterns. For cemented tibial components there was no difference in migration between all-poly and metal-backed components, between mobile bearing and fixed bearing, between cruciate retaining and posterior stabilized. Furthermore, no difference existed between TKR measured with model-based RSA or marker-based RSA methods. For uncemented TKR there was some variation in migration with the highest migration for uncoated TKR. Interpretation - The results from this meta-analysis on RSA migration of TKR are in line with both the survival analyses results from joint registries of these TKRs as well as revision rates results from meta-analyses, thus providing further proof for the association between early migration and late revision for loosening. The pooled migration patterns can be used both as benchmarks and for defining migration thresholds for future evaluation of new TKR.

[Total knee arthroplasty by lateral parapatellar approach for valgus knee].

PubMed

Zhou, Dian-ge; Zhang, Bin; Kou, Bo-long; Lü, Hou-shan

2007-07-17

To investigate the effect of lateral parapatellar approach in total knee arthroplasty (TKA) of valgus knee. Lateral parapatellar approach of total knee arthroplasty was applied in 8 patients (10 knees) with severe valgus osteoarthritis knee (bilateral in 2 cases and unilateral in 6 cases), with the valgus angle > 15 degrees , 1 male (1 knee) and 7 females (9 knee), aged 68.2 (58 - 79), 7 cases (9 knees) being of the Krackow type I and 1 case (1 knee) of the Krackow type I, I. After incision of the skin through lateral knee, ilio-tibial band was prolonged by apple pie arthroplasty. The joint capsule was cut open laterally 2 - 4 cm from the para-patellar edge. Soft tissue balance was performed by releasing I - T band in Gerdy tubercle, lateral collateral ligament and poster-lateral capsule from the femur and tibial side. Valgus angle of distal femur cutting were five degree. Whiteside line and trans-epicondylar line were used as AP rotational cutting reference. All patellar of the group were resurfaced. Capsule closure is completed with the knee flexed. The expanded deep lateral soft tissue sleeve (coronal Z-plasty) is sutured with the medial retinaculum sleeve (superficial layer). Follow-up was conducted for 19.6 months (1 - 51 months). Seven cases (9 knees) were replaced by posterior stabilized cemented prostheses (TC-Dynamic, PLUS), one case (1 knee) was replaced by RT prosthesis (RT-PLUS(TM) Solution, PLUS). After operation, the valgus deformity of all patients was corrected and all patients could walk 100 m with or without the help of walking holders. The average range of motion (ROM) was improved from the pre-operative. 95.6 degrees (85 degrees - 110 degrees ) to the post-operative 117.1 degrees (100 degrees - 125 degrees ). The average femorotibial angle (FTA) was corrected from the pre-operative. 27.6 degrees (20 degrees - 40 degrees ) to the post-operative 6.8 degrees (5 degrees - 9 degrees ). The Knee Score System (KSS) score and functional score were

Periprosthetic Fractures Following Total Knee Arthroplasty

PubMed Central

Kim, Nam Ki

2015-01-01

Periprosthetic fractures after total knee arthroplasty may occur in any part of the femur, tibia and patella, and the most common pattern involves the supracondylar area of the distal femur. Supracondylar periprosthetic fractures frequently occur above a well-fixed prosthesis, and risk factors include anterior femoral cortical notching and use of the rotational constrained implant. Periprosthetic tibial fractures are frequently associated with loose components and malalignment or malposition of implants. Fractures of the patella are much less common and associated with rheumatoid arthritis, use of steroid, osteonecrosis and malalignment of implants. Most patients with periprosthetic fractures around the knee are the elderly with poor bone quality. There are many difficulties and increased risk of nonunion after treatment because reduction and internal fixation is interfered with by preexisting prosthesis and bone cement. Additionally, previous soft tissue injury is another disadvantageous condition for bone healing. Many authors reported good clinical outcomes after non-operative treatment of undisplaced or minimally displaced periprosthetic fractures; however, open reduction or revision arthroplasty was required in displaced fractures or fractures with unstable prosthesis. Periprosthetic fractures around the knee should be prevented by appropriate technique during total knee arthroplasty. Nevertheless, if a periprosthetic fracture occurs, an appropriate treatment method should be selected considering the stability of the prosthesis, displacement of fracture and bone quality. PMID:25750888

Clinical Outcome of Medial Pivot Compared With Press-Fit Condylar Sigma Cruciate-Retaining Mobile-Bearing Total Knee Arthroplasty.

PubMed

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

2017-10-01

The purpose of this study was to compare the long-term clinical results, radiographic results, range of knee motion, patient satisfaction, and the survival rate of Medial-Pivot posterior cruciate-substituting, knee prosthesis and a press-fit condylar (PFC) Sigma cruciate-retaining mobile-bearing knee prosthesis in the same patients. One hundred eighty-two patients received Medial-Pivot knee prosthesis in one knee and a PFC Sigma knee prosthesis in the contralateral knee. The minimum duration of follow-up was 11 years (range, 11-12.6 years). The knees with a Medial-Pivot knee prosthesis had significantly worse results than those with a PFC Sigma knee prosthesis at the final follow-up with regard to the mean postoperative Knee Society knee scores (90 compared with 95 points), Western Ontario and McMaster Universities Osteoarthritis Index score (25 compared with 18 points), and range of knee motion (117° compared with 128°). Patients were more satisfied with PFC Sigma knee prosthesis (93%) than with Medial-Pivot knee prosthesis (75%). Complication rates were significantly higher in the Medial-Pivot knee group (26%) than those in the PFC Sigma knee group (6.5%). Radiographic results and survival rates (99% compared with 99.5%) were similar between the 2 groups. Although the long-term fixation and survival rate of both Medial-Pivot and PFC Sigma prostheses were similar, we observed a worse knee score, worse range of knee motion, and patient satisfaction was less in the Medial-Pivot knee group than in the PFC Sigma knee group. Furthermore, complication rate was also higher in the Medial-Pivot knee group than the other group. Copyright © 2017 Elsevier Inc. All rights reserved.

Why Do Medial Unicompartmental Knee Arthroplasties Fail Today?

PubMed

van der List, Jelle P; Zuiderbaan, Hendrik A; Pearle, Andrew D

2016-05-01

Failure rates are higher in medial unicompartmental knee arthroplasty (UKA) than total knee arthroplasty. To improve these failure rates, it is important to understand why medial UKA fail. Because individual studies lack power to show failure modes, a systematic review was performed to assess medial UKA failure modes. Furthermore, we compared cohort studies with registry-based studies, early with midterm and late failures and fixed-bearing with mobile-bearing implants. Databases of PubMed, EMBASE, and Cochrane and annual registries were searched for medial UKA failures. Studies were included when they reported >25 failures or when they reported early (<5 years), midterm (5-10 years), or late failures (>10 years). Thirty-seven cohort studies (4 level II studies and 33 level III studies) and 2 registry-based studies were included. A total of 3967 overall failures, 388 time-dependent failures, and 1305 implant design failures were identified. Aseptic loosening (36%) and osteoarthritis (OA) progression (20%) were the most common failure modes. Aseptic loosening (26%) was most common early failure mode, whereas OA progression was more commonly seen in midterm and late failures (38% and 40%, respectively). Polyethylene wear (12%) and instability (12%) were more common in fixed-bearing implants, whereas pain (14%) and bearing dislocation (11%) were more common in mobile-bearing implants. This level III systematic review identified aseptic loosening and OA progression as the major failure modes. Aseptic loosening was the main failure mode in early years and mobile-bearing implants, whereas OA progression caused most failures in late years and fixed-bearing implants. Copyright © 2016 Elsevier Inc. All rights reserved.

Normal axial alignment of the lower extremity and load-bearing distribution at the knee.

PubMed

Hsu, R W; Himeno, S; Coventry, M B; Chao, E Y

1990-06-01

Based on a series of 120 normal subjects of different gender and age, the geometry of the knee joint was analyzed using a full-length weight-bearing roentgenogram of the lower extremity. A special computer program based on the theory of a rigid body spring model was applied to calculate the important anatomic and biomechanical factors of the knee joint. The tibiofemoral mechanical angle was 1.2 degrees varus. Hence, it is difficult to rationalize the 3 degree varus placement of the tibial component in total knee arthroplasty suggested by some authors. The distal femoral anatomic valgus (measured from the lower one-half of the femur) was 4.2 degrees in reference to its mechanical axis. This angle became 4.9 degrees when the full-length femoral anatomic axis was used. When simulating a one-legged weight-bearing stance by shifting the upper-body gravity closer to the knee joint, 75% of the knee joint load passed through the medial tibial plateau. The knee joint-line obliquity was more varus in male subjects. The female subjects had a higher peak joint pressure and a greater patello-tibial Q angle. Age had little effect on the factors relating to axial alignment of the lower extremity and load transmission through the knee joint.

The 180° spin of meniscal bearing in unicompartmental knee arthroplasty.

PubMed

Lee, Su Chan; Hwang, Seung Hyun; Nam, Chang Hyun; Ryu, Seung Ryol; Ahn, Hye Sun

2017-01-01

Mobile-bearing Oxford medial unicompartmental knee arthroplasty (UKA) has been widely used and has produced good results in the treatment of medial compartmental osteoarthritis. But it is associated with the potential risk of meniscal bearing dislocation. Symptoms caused by most meniscal bearing dislocations include acute pain, knee swelling, and locking. We report two unusual cases of meniscal bearing spinning of 180° without remarkable symptoms, which would have been easily missed if we had not watched carefully. Therefore, if there is sudden locking, pain, swelling, or a slight locking history, the possibility of meniscal bearing spin out as well as meniscal bearing dislocation should be considered and the direction of meniscal bearing markers should be confirmed, especially on lateral radiographs.

[CLINICAL APPLICATION OF OXFORD MOBILE-BEARING BIPOLAR PROSTHESIS UNICOMPARTMENTAL KNEE ARTHROPLASTY FOR SINGLE COMPARTMENTAL KNEE OSTEOARTHRITIS].

PubMed

Wang, Shangzeng; Cheng, Shao; Wang, Yisheng

2016-01-01

To evaluate the effectiveness of Oxford mobile-bearing bipolar prosthesis unicompartmental knee arthroplasty (UKA) in the treatment of single compartmental knee osteoarthritis. Between June 2011 and July 2013, 22 cases of single compartmental knee osteoarthritis were treated by Oxford mobile-bearing bipolar prosthesis UKA. Of 22 cases, 8 were male and 14 were female with an average age of 65 years (range, 45-80 years); the left knee was involved in 12 cases, and the right knee in 10 cases, with a mean disease duration of 32.5 months (range, 8-90 months). The mean weight was 55.2 kg (range, 50-65 kg), and the mean body mass index was 20.8 kg/m2 (range, 17-25 kg/m2). Osteoarthritis involved in the single knee medial compartment in all patients. Knee society score (KSS) and range of motion (ROM) were measured to evaluate the knee joint function. Primary healing of incision was obtained in all patients, and there was no complication of infection, bedsore, or deep venous thrombosis. Postoperative follow-up was 2-4 years (mean, 3.2 years). The X-ray films showed good position of prosthesis, no prosthesis dislocation, or periprosthetic infection during follow-up. Knee ROM, KSS function score, and KSS clinical score were significantly improved at 1 week after operation and at last follow-up when compared with preoperative ones (P < 0.05), but no significant difference was shown between at 1 week and at last follow-up (P > 0.05). Oxford mobile-bearing bipolar prosthesis UKA is an effective method to treat single compartmental knee osteoarthritis, with the advantages of less trauma, earlier rehabilitation exercise, near physiological state in joint function, and less risk of complications.

10-year evaluation of the cementless low-contact- stress rotating-platform total knee arthroplasty.

PubMed

Efstathopoulos, Nikolaos; Mavrogenis, Andreas F; Lallos, Stergios; Nikolaou, Vassilios; Papagelopoulos, Panayiotis J; Savvidou, Olga D; Korres, Demetrios S

2009-01-01

We present the clinical and radiographic outcomes of the cementless low-contact-stress (LCS) rotating-platform total knee arthroplasty. Overall, 423 prostheses were implanted in 393 consecutive patients (30 patients had bilateral total knee replacement) for primary varus gonarthrosis (381 patients) and rheumatoid arthritis (12 patients). There were 81 men and 312 women with a mean age of 73 years (range, 58-85 years). Patella replacement was not performed in any case. Clinical and radiographic evaluation was performed using the Knee Society Score (KSS) and the Knee Society Assessment Form, respectively. The mean follow-up was 10 years (range, 5-15 years). Three patients were lost to follow-up. Survival of the prostheses was 98% at 10 years; three prostheses required revision for deep infection, bearing dislocation, and periprosthetic fracture. The mean KSS improved significantly, from 42 and 44 points preoperatively to 90 and 79 points, respectively, at the latest evaluation (P < 0.001); results were excellent in 278 cases, good in 106, fair in 27, and poor in nine. Radiolucent lines were observed in 80 cases; revision arthroplasty was not performed in any of these cases. Complications included deep infection in one patient, bearing dislocation in one, skin necrosis in four, and a supracondylar fracture in one. The cementless LCS rotating-platform total knee arthroplasty is associated with excellent mid- and long-term results for patients with osteoarthritis and rheumatoid arthritis of the knee.

Which total knee replacement implant should I pick? Correcting the pathology: the role of knee bearing designs.

PubMed

Berend, K R; Lombardi, A V; Adams, J B

2013-11-01

Debate has raged over whether a cruciate retaining (CR) or a posterior stabilised (PS) total knee replacement (TKR) provides a better range of movement (ROM) for patients. Various sub-sets of CR design are frequently lumped together when comparing outcomes. Additionally, multiple factors have been proven to influence the rate of manipulation under anaesthetic (MUA) following TKR. The purpose of this study was to determine whether different CR bearing insert designs provide better ROM or different MUA rates. All primary TKRs performed by two surgeons between March 2006 and March 2009 were reviewed and 2449 CR-TKRs were identified. The same CR femoral component, instrumentation, and tibial base plate were consistently used. In 1334 TKRs a CR tibial insert with 3° posterior slope and no posterior lip was used (CR-S). In 803 there was an insert with no slope and a small posterior lip (CR-L) and in 312 knees the posterior cruciate ligament (PCL) was either resected or lax and a deep-dish, anterior stabilised insert was used (CR-AS). More CR-AS inserts were used in patients with less pre-operative ROM and greater pre-operative tibiofemoral deformity and flexion contracture (p < 0.05). The mean improvement in ROM was highest for the CR-AS inserts (5.9° (-40° to 55°) vs CR-S 3.1° (-45° to 70°) vs CR-L 3.0° (-45° to 65°); p = 0.004). There was a significantly higher MUA rate with the CR-S and CR-L inserts than CR-AS (Pearson rank 6.51; p = 0.04). Despite sacrificing or not substituting for the PCL, ROM improvement was highest, and the MUA rate was lowest in TKRs with a deep-dish, anterior-stabilised insert. Substitution for the posterior cruciate ligament (PCL) in the form of a PS design may not be necessary even when the PCL is deficient.

The use of synthetic ligaments in the design of an enhanced stability total knee joint replacement.

PubMed

Stokes, Michael D; Greene, Brendan C; Pietrykowski, Luke W; Gambon, Taylor M; Bales, Caroline E; DesJardins, John D

2018-03-01

Current total knee replacement designs work to address clinically desired knee stability and range of motion through a balance of retained anatomy and added implant geometry. However, simplified implant geometries such as bearing surfaces, posts, and cams are often used to replace complex ligamentous constraints that are sacrificed during most total knee replacement procedures. This article evaluates a novel total knee replacement design that incorporates synthetic ligaments to enhance the stability of the total knee replacement system. It was hypothesized that by incorporating artificial cruciate ligaments into a total knee replacement design at specific locations and lengths, the stability of the total knee replacement could be significantly altered while maintaining active ranges of motion. The ligament attachment mechanisms used in the design were evaluated using a tensile test, and determined to have a safety factor of three with respect to expected ligamentous loading in vivo. Following initial computational modeling of possible ligament orientations, a physical prototype was constructed to verify the function of the design by performing anterior/posterior drawer tests under physiologic load. Synthetic ligament configurations were found to increase total knee replacement stability up to 94% compared to the no-ligament case, while maintaining total knee replacement flexion range of motion between 0° and 120°, indicating that a total knee replacement that incorporates synthetic ligaments with calibrated location and lengths should be able to significantly enhance and control the kinematic performance of a total knee replacement system.

In vitro kinematic measurements of the patellar tendon in two different types of posterior-stabilized total knee arthroplasties.

PubMed

Zhu, Zhonglin; Ding, Hui; Dang, Xiao; Tang, Jing; Zhou, Yixin; Wang, Guangzhi

2010-01-01

Fixed-bearing posterior-stabilized (PS) total knee arthroplasty (TKA) has been used in Asian countries for several years, but few studies have investigated differences in the kinematic properties of the patellar tendon after standard PS TKA as compared to high-flex PS TKA. To quantify the in vitro three-dimensional (3D) kinematics of the patellar tendon during passive high flexion and full extension before and after two different types of PS TKAs. Six fresh-frozen cadaveric knees were tested under the following conditions: the unaltered state, status-post traditional PS prostheses (Simth-nephew GENESIS II) replacement, and status-post high-flexion PS prostheses replacement. The soft tissue around the knee and the quadriceps muscle were preserved, then tested under the load of a specific weight in an Oxford knee rig. We designed a specialized rigid body with four active markers fixed to each bone to track the 3D passive motion of the cadaveric knees. Flexion and extension was controlled by the knee rig and captured by an Optotrak Certus high precision optical tracking system. The attachment sites of the patellar tendon were registered as virtual markers to calculate the 3D kinematics. The patellar tendon of the unaltered knee and both TKA knees showed similar deformation. We found the length of the patellar tendon changed significantly during a motion from full extension to 30°, but there was no significant change in length while undergoing a motion from 30° to full flexion. Both the sagittal plane and coronal plane angles of the patellar tendon decreased after PS TKAs. There was no significant difference in patellar tendon kinematics between the two types of PS TKAs. We believe the changes observed in the sagittal plane and coronal plane angles of the patellar tendon after PS TKAs may influence the extensor mechanism and be an important cause of patella-femoral complications. These data may be used to assess patella-femoral complications after surgery so as to

Inducible displacement of cemented tibial components ten years after total knee arthroplasty.

PubMed

Lam Tin Cheung, K; Lanting, B A; McCalden, R W; Yuan, X; MacDonald, S J; Naudie, D D; Teeter, M G

2018-02-01

The aim of this study was to evaluate the long-term inducible displacement of cemented tibial components ten years after total knee arthroplasty (TKA). A total of 15 patients from a previously reported prospective trial of fixation using radiostereometric analysis (RSA) were examined at a mean of 11 years (10 to 11) postoperatively. Longitudinal supine RSA examinations were acquired at one week, one year, and two years postoperatively and at final follow-up. Weight-bearing RSA examinations were also undertaken with the operated lower limb in neutral and in maximum internal rotation positions. Maximum total point motion (MTPM) was calculated for the longitudinal and inducible displacement examinations (supine versus standing, standing versus internal rotation, and supine versus standing with internal rotation). All patients showed some inducible displacement. Two patients with radiolucent lines had greater mean standing-supine MTPM displacement (1.35; sd 0.38) compared with the remaining patients (0.68; sd 0.36). These two patients also had a greater mean longitudinal MTPM at ten years (0.64; sd 0.50) compared with the remaining patients (0.39; sd 0.13 mm). Small inducible displacements in well-fixed cemented tibial components were seen ten years postoperatively, of a similar magnitude to that which has been reported for well-fixed components one to two years postoperatively. Greater displacements were found in components with radiolucent lines. Cite this article: Bone Joint J 2018;100-B:170-5. ©2018 The British Editorial Society of Bone & Joint Surgery.

Gender differences in knee abduction during weight-bearing activities: A systematic review and meta-analysis.

PubMed

Cronström, Anna; Creaby, Mark W; Nae, Jenny; Ageberg, Eva

2016-09-01

Increased knee abduction during weight-bearing activities is suggested to be a contributing factor for the high knee injury risk reported in women. However, studies investigating gender difference in knee abduction are inconclusive. To systematically review gender-differences in knee abduction during weight-bearing activities in individuals with or without knee injury. A systematic review and meta-analysis were conducted according to the PRISMA guidelines. A search in the databases Medline, CINAHL and EMBASE was performed until September 2015. Inclusion criteria were studies that reported (1) gender differences, (2) healthy individuals and/or those with anterior cruciate ligament (ACL) deficiency or reconstruction or patellofemoral pain PFP, and (3) knee abduction assessed with either motion analysis or visual observation during weight-bearing activity. Fifty-eight articles met the inclusion criteria. Women with PFP had greater peak knee abduction compared to men (Std diff in mean; -1.34, 95%CI; -1.83 to -0.84). In healthy individuals, women performed weight-bearing tasks with greater knee abduction throughout the movement (initial contact, peak abduction, excursion) (Std diff in mean; -0.68 to -0.79, 95%CI; -1.04 to -0.37). In subgroup analyses by task, differences in knee abduction between genders were present for most tasks, including running, jump landings and cutting movements. There were too few studies in individuals with ACL injury to perform meta-analysis. The gender difference in knee abduction during weight-bearing activities should be considered in training programs aimed at preventing or treating knee injury. Copyright © 2016 Elsevier B.V. All rights reserved.

The influence of simulator input conditions on the wear of total knee replacements: An experimental and computational study

PubMed Central

Brockett, Claire L; Abdelgaied, Abdellatif; Haythornthwaite, Tony; Hardaker, Catherine; Fisher, John; Jennings, Louise M

2016-01-01

Advancements in knee replacement design, material and sterilisation processes have provided improved clinical results. However, surface wear of the polyethylene leading to osteolysis is still considered the longer-term risk factor. Experimental wear simulation is an established method for evaluating the wear performance of total joint replacements. The aim of this study was to investigate the influence of simulation input conditions, specifically input kinematic magnitudes, waveforms and directions of motion and position of the femoral centre of rotation, on the wear performance of a fixed-bearing total knee replacement through a combined experimental and computational approach. Studies were completed using conventional and moderately cross-linked polyethylene to determine whether the influence of these simulation input conditions varied with material. The position of the femoral centre of rotation and the input kinematics were shown to have a significant influence on the wear rates. Similar trends were shown for both the conventional and moderately cross-linked polyethylene materials, although lower wear rates were found for the moderately cross-linked polyethylene due to the higher level of cross-linking. The most important factor influencing the wear was the position of the relative contact point at the femoral component and tibial insert interface. This was dependent on the combination of input displacement magnitudes, waveforms, direction of motion and femoral centre of rotation. This study provides further evidence that in order to study variables such as design and material in total knee replacement, it is important to carefully control knee simulation conditions. This can be more effectively achieved through the use of displacement control simulation. PMID:27160561

Contact Mechanics and Failure Modes of Compliant Polymeric Bearing Materials for Knee Cartilage Replacement

NASA Astrophysics Data System (ADS)

Tohfafarosh, Mariya Shabbir

failed under tension between 250 - 750% true strain, while those under uniaxial and biaxial compression test sustained compression of 50 - 70% engineering strain (39 - 53% true strain) without any signs of cracking or fracture. The tension was determined to be the primary failure mode for the proposed materials, and the tensile test was used to define the failure criteria of the materials. The unconfined compression tests were used to define the yield stresses and strains under compression, which is the main mode of loading for the knee joint. The results of the plane strain compression were modeled using a finite element model and the maximum principal stress, von Mises stress, maximum shear stress, and maximum principal strain failure criteria were predicted at the corresponding yield strain of each material formulation. Upon comparing the knee model contact stress and strain prediction under normal walking and stair climbing loads with those of the empirical failure criteria at yield, the polycarbonate urethane showed better overall potential for use in compliant knee implants, while the hydrogels exhibited higher potential for delamination or fracture, especially if appropriate implant conformity and thickness are not employed. The outcome of this study and the previous parametric model results helped to determine a niche design space within which designing a knee implant with compliant bearing materials may be feasible. In summary, the potential of compliant bearing materials was thoroughly examined in this thesis, and the results provided a foundation for future testing and development of a compliant cartilage replacement implant. Such an implant would be a promising improvement and alternative to conventional total knee replacements.

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

PubMed

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

2017-12-01

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

Does lateral versus medial exposure influence total knee tibial component final external rotation? A CT based study.

PubMed

Passeron, D; Gaudot, F; Boisrenoult, P; Fallet, L; Beaufils, P

2009-10-01

A previous study demonstrated that performing a total knee arthroplasty through a lateral approach including anterior tibial tuberosity (ATT) osteotomy (refixed in its original position) presented numerous advantages: correcting the preoperative patella lateral tilt and improving postoperative patella tracking. We hypothesized that these improvements in patella centering were, at least in part, due to an increased external rotation of the tibial component. Postoperative scannographic studies were, therefore, undertaken to measure tibial component rotation and analyze the results according the medial and lateral exposure used. Rotational positioning of the tibial component is influenced by the lateral or medial approach selected at surgery. Forty-five CAT scans, performed according to the protocol criteria of the French Hip and Knee Society (SFHG), were studied 3 months postoperatively: 15 knees operated through the lateral approach and 30 knees operated through a standard medial approach. The total knee utilized in all these cases was a posteriorly stabilized, fixed-bearing, design. We measured first the angle formed between the perpendicular to the transverse axis of the tibial component and the axis joining the ATT to the center of the knee; second we also measured the coronal distance between the center of the component and the anterior tibial tuberosity (ATT). In the group using the medial approach, the lateral position of the ATT was 7 + or - 3mm with a rotation angle of 18 degrees . In the group using the lateral approach these measurements were respectively 1 + or - 4mm and 2 degrees (p<0.0001). External rotation of the tibial component is substantially increased by the lateral approach compared to the medial approach. Better exposure of the lateral tibial plateau is probably responsible of this difference. This increased external rotation improves postoperative patella tracking. Prospective; comparative; non-randomized study; level 3. 2009 Elsevier Masson

Sex differences in coupled knee motions during the transition from non-weight bearing to weight bearing.

PubMed

Shultz, Sandra J; Beynnon, Bruce D; Schmitz, Randy J

2009-06-01

Knee ligament injuries frequently happen when the joint transitions from non-weight bearing (NWB) to weight bearing (WB). To gain insight into the mechanism that produces these injuries, physically active females (N = 41) and males (N = 39) underwent measurement of coupled tibiofemoral joint displacements [anterior tibial translation (ATT) and varus-valgus and internal-external rotations] and neuromuscular responses as the knee transitioned from NWB to WB in response to a 40% body weight load applied under the control of gravity. The transition from NWB to WB produced no difference in ATT between males and females; however, significant sex-based differences were noted for both transverse and frontal plane knee motions. With the knee NWB, females were in a greater absolute valgus compared to males (6.6 vs. 5.0 degrees), and moved through greater varus motion than males during the transition from NW to WB (2.3 vs. 1.4 degrees), resulting in similar valgus alignment for both sexes at peak WB (4.3 vs. 3.6 degrees). In the transverse plane, the knees of females were positioned in more external rotation compared to males when NWB (1.4 vs. -0.3 degrees), then females externally rotated their knees while males internally rotated their knees during the transition from NWB to WB. This resulted in a 3.4 degrees difference in transverse plane knee position at peak WB (2.3 vs. -1.1 degrees). Our findings suggest that the coupled knee motions produced during the transition from NWB to WB are sex dependent, and may provide insight into the knee motion patterns that place females at increased risk of knee ligament injury. Copyright 2008 Orthopaedic Research Society

Surgical practices in total knee arthroplasty in Turkey.

PubMed

Erduran, Mehmet; Akseki, Devrim; Araç, Sükrü

2012-01-01

The aim of this study was to determine the current practices in the total knee arthroplasty (TKA) and the differences of practice among the orthopedic surgeons in Turkey. Data in this cross-sectional and descriptive study was collected through a questionnaire from 76 orthopaedic surgeons performing TKA. The questionnaire form contained 57 questions under four main headings, covering the professional properties of the surgeon, pre-surgery approach, surgical technique applied for TKA and the surgical details peculiar to the technique with solutions applied for complication scenarios, and finally the postoperative approach. It was determined that 39.7% of the TKA applications were performed in operating theatres without laminar airflow or HEPA filters. Nearly 1/5 of the surgeons used more than one antibiotic for prophylaxis, and more than 85% continued prophylaxis use over 3 days. Low-molecular-weight heparin was the most commonly used method for thromboprophylaxis. 94.67% of the surgeons used only the cemented technique in primary TKA. 44% indicated that they performed simultaneous bilateral arthroplasty, 89% did not use any scoring system and 72.37% preferred fixed-bearing and posterior-cruciate-retaining type prosthesis. Results showed no standardization in TKA surgery among surgeons in Turkey, and important educational deficiencies were noted.

[Mini-subvastus approach for total knee replacement].

PubMed

Halder, Andreas; Beier, Alexander; Neumann, Wolfram

2009-03-01

Total knee replacement in minimally invasive technique without any trauma to the extensor apparatus and with soft-tissue-referenced bone resections. Only the subvastus approach preserves the integrity of the extensor apparatus and has therefore been modified to become a minimally invasive technique with a shorter skin incision and lateralization instead of eversion of the patella. Soft-tissue balancing is done through this direct anterior approach. Mild to moderate varus osteoarthritis of the knee up to 15 degrees of malalignment, mild and passively correctable valgus osteoarthritis of the knee up to 10 degrees of malalignment. Severe, contract varus osteoarthritis of the knee, severe and moderate, contract valgus osteoarthritis of the knee, severe obesity, exceptionally muscular patients, decreased skin perfusion. Central skin incision from the superior pole of the patella to the tibial tubercle. Exposure of the medial retinaculum and mobilization of the vastus medialis muscle subcutaneously. Incision of the medial retinaculum and blunt separation of the vastus medialis muscle from the intermuscular septum. Lateralization of the patella and flexion of the knee joint. Resection of the tibia perpendicular to the diaphysis. Adjustment of the anteroposterior (AP) resection block at the level of the anterior femoral cortex and of rotation by applying equal tension to the collateral ligaments. Balancing of soft-tissue tension in flexion gap by release, if necessary. After AP resection fixation of distal resection block in planned valgus angle. Balancing of soft-tissue tension in extension gap by release, if necessary. After distal femur resection facet resection, adaptation of posterior femoral condyles, and implantation of prosthesis. Check on stability and range of motion. Wound closure. Full weight bearing from the 1st postoperative day, CPM (continuous passive motion) with up to 90 degrees flexion with peridural anesthesia as tolerated, stair climbing starting on

Tibial Tray Thickness Significantly Increases Medial Tibial Bone Resorption in Cobalt-Chromium Total Knee Arthroplasty Implants.

PubMed

Martin, J Ryan; Watts, Chad D; Levy, Daniel L; Miner, Todd M; Springer, Bryan D; Kim, Raymond H

2017-01-01

Stress shielding is an uncommon complication associated with primary total knee arthroplasty. Patients are frequently identified radiographically with minimal clinical symptoms. Very few studies have evaluated risk factors for postoperative medial tibial bone loss. We hypothesized that thicker cobalt-chromium tibial trays are associated with increased bone loss. We performed a retrospective review of 100 posterior stabilized, fixed-bearing total knee arthroplasty where 50 patients had a 4-mm-thick tibial tray (thick tray cohort) and 50 patients had a 2.7-mm-thick tibial tray (thin tray cohort). A clinical evaluation and a radiographic assessment of medial tibial bone loss were performed on both cohorts at a minimum of 2 years postoperatively. Mean medial tibial bone loss was significantly higher in the thick tray cohort (1.07 vs 0.16 mm; P = .0001). In addition, there were significantly more patients with medial tibial bone loss in the thick tray group compared with the thin tray group (44% vs 10%, P = .0002). Despite these differences, there were no statistically significant differences in range of motion, knee society score, complications, or revision surgeries performed. A thicker cobalt-chromium tray was associated with significantly more medial tibial bone loss. Despite these radiographic findings, we found no discernable differences in clinical outcomes in our patient cohort. Further study and longer follow-up are needed to understand the effects and clinical significance of medial tibial bone loss. Copyright © 2016 Elsevier Inc. All rights reserved.

Development and validation of a weight-bearing finite element model for total knee replacement.

PubMed

Woiczinski, M; Steinbrück, A; Weber, P; Müller, P E; Jansson, V; Schröder, Ch

2016-01-01

Total knee arthroplasty (TKA) is a successful procedure for osteoarthritis. However, some patients (19%) do have pain after surgery. A finite element model was developed based on boundary conditions of a knee rig. A 3D-model of an anatomical full leg was generated from magnetic resonance image data and a total knee prosthesis was implanted without patella resurfacing. In the finite element model, a restarting procedure was programmed in order to hold the ground reaction force constant with an adapted quadriceps muscle force during a squat from 20° to 105° of flexion. Knee rig experimental data were used to validate the numerical model in the patellofemoral and femorotibial joint. Furthermore, sensitivity analyses of Young's modulus of the patella cartilage, posterior cruciate ligament (PCL) stiffness, and patella tendon origin were performed. Pearson's correlations for retropatellar contact area, pressure, patella flexion, and femorotibial ap-movement were near to 1. Lowest root mean square error for retropatellar pressure, patella flexion, and femorotibial ap-movement were found for the baseline model setup with Young's modulus of 5 MPa for patella cartilage, a downscaled PCL stiffness of 25% compared to the literature given value and an anatomical origin of the patella tendon. The results of the conducted finite element model are comparable with the experimental results. Therefore, the finite element model developed in this study can be used for further clinical investigations and will help to better understand the clinical aspects after TKA with an unresurfaced patella.

Subsequent Total Joint Arthroplasty After Primary Total Knee or Hip Arthroplasty

PubMed Central

Sanders, Thomas L.; Maradit Kremers, Hilal; Schleck, Cathy D.; Larson, Dirk R.; Berry, Daniel J.

2017-01-01

Background: Despite the large increase in total hip arthroplasties and total knee arthroplasties, the incidence and prevalence of additional contralateral or ipsilateral joint arthroplasty are poorly understood. The purpose of this study was to determine the rate of additional joint arthroplasty after a primary total hip arthroplasty or total knee arthroplasty. Methods: This historical cohort study identified population-based cohorts of patients who underwent primary total hip arthroplasty (n = 1,933) or total knee arthroplasty (n = 2,139) between 1969 and 2008. Patients underwent passive follow-up through their medical records beginning with the primary total hip arthroplasty or total knee arthroplasty. We assessed the likelihood of undergoing a subsequent total joint arthroplasty, including simultaneous and staged bilateral procedures. Age, sex, and calendar year were evaluated as potential predictors of subsequent arthroplasty. Results: During a mean follow-up of 12 years after an initial total hip arthroplasty, we observed 422 contralateral total hip arthroplasties (29% at 20 years), 76 contralateral total knee arthroplasties (6% at 10 years), and 32 ipsilateral total knee arthroplasties (2% at 20 years). Younger age was a significant predictor of contralateral total hip arthroplasty (p < 0.0001), but not a predictor of the subsequent risk of total knee arthroplasty. During a mean follow-up of 11 years after an initial total knee arthroplasty, we observed 809 contralateral total knee arthroplasties (45% at 20 years), 31 contralateral total hip arthroplasties (3% at 20 years), and 29 ipsilateral total hip arthroplasties (2% at 20 years). Older age was a significant predictor of ipsilateral or contralateral total hip arthroplasty (p < 0.001). Conclusions: Patients undergoing total hip arthroplasty or total knee arthroplasty can be informed of a 30% to 45% chance of a surgical procedure in a contralateral cognate joint and about a 5% chance of a surgical procedure

Are There Differences in Gait Mechanics in Patients With A Fixed Versus Mobile Bearing Total Ankle Arthroplasty? A Randomized Trial.

PubMed

Queen, Robin M; Franck, Christopher T; Schmitt, Daniel; Adams, Samuel B

2017-10-01

Total ankle arthroplasty (TAA) is an alternative to arthrodesis, but no randomized trial has examined whether a fixed bearing or mobile bearing implant provides improved gait mechanics. We wished to determine if fixed- or mobile-bearing TAA results in a larger improvement in pain scores and gait mechanics from before surgery to 1 year after surgery, and to quantify differences in outcomes using statistical analysis and report the standardized effect sizes for such comparisons. Patients with end-stage ankle arthritis who were scheduled for TAA between November 2011 and June 2013 (n = 40; 16 men, 24 women; average age, 63 years; age range, 35-81 years) were prospectively recruited for this study from a single foot and ankle orthopaedic clinic. During this period, 185 patients underwent TAA, with 144 being eligible to participate in this study. Patients were eligible to participate if they were able to meet all study inclusion criteria, which were: no previous diagnosis of rheumatoid arthritis, a contralateral TAA, bilateral ankle arthritis, previous revision TAA, an ankle fusion revision, or able to walk without the use of an assistive device, weight less than 250 pounds (114 kg), a sagittal or coronal plane deformity less than 15°, no presence of avascular necrosis of the distal tibia, no current neuropathy, age older than 35 years, no history of a talar neck fracture, or an avascular talus. Of the 144 eligible patients, 40 consented to participate in our randomized trial. These 40 patients were randomly assigned to either the fixed (n = 20) or mobile bearing implant group (n = 20). Walking speed, bilateral peak dorsiflexion angle, peak plantar flexion angle, sagittal plane ankle ROM, peak ankle inversion angle, peak plantar flexion moment, peak plantar flexion power during stance, peak weight acceptance, and propulsive vertical ground reaction force were analyzed during seven self-selected speed level walking trials for 33 participants using an eight

A randomised controlled trial of the clinical effectiveness and cost-effectiveness of different knee prostheses: the Knee Arthroplasty Trial (KAT).

PubMed

Murray, David W; MacLennan, Graeme S; Breeman, Suzanne; Dakin, Helen A; Johnston, Linda; Campbell, Marion K; Gray, Alastair M; Fiddian, Nick; Fitzpatrick, Ray; Morris, Richard W; Grant, Adrian M

2014-03-01

In the late 1990s, new developments in knee replacement were identified as a priority for research within the NHS. The newer forms of arthroplasty were more expensive and information was needed on their safety and cost-effectiveness. The Knee Arthroplasty Trial examined the clinical effectiveness and cost-effectiveness of four aspects of knee replacement surgery: patellar resurfacing, mobile bearings, all-polyethylene tibial components and unicompartmental replacement. This study comprised a partial factorial, pragmatic, multicentre randomised controlled trial with a trial-based cost-utility analysis which was conducted from the perspective of the NHS and the patients treated. Allocation was computer generated in a 1 : 1 ratio using a central system, stratified by eligible comparisons and surgeon, minimised by participant age, gender and site of disease. Surgeons were not blinded to allocated procedures. Participants were unblinded if they requested to know the prosthesis they received. The setting for the trial was UK secondary care. Patients were eligible for inclusion if a decision had been made for them to have primary knee replacement surgery. Patients were recruited to comparisons for which the surgeon was in equipoise about which type of operation was most suitable. Patients were randomised to receive a knee replacement with the following: patellar resurfacing or no patellar resurfacing irrespective of the design of the prosthesis used; a mobile bearing between the tibial and femoral components or a bearing fixed to the tibial component; a tibial component made of either only high-density polyethylene ('all polyethylene') or a polyethylene bearing fixed to a metal backing plate with attached stem; or unicompartmental or total knee replacement. The primary outcome was the Oxford Knee Score (OKS). Other outcomes were Short Form 12; EuroQol 5D; intraoperative and postoperative complications; additional surgery; cost; and cost-effectiveness. Patients were

Embedded piezoelectrics for sensing and energy harvesting in total knee replacement units

NASA Astrophysics Data System (ADS)

Wilson, Brooke E.; Meneghini, Michael; Anton, Steven R.

2015-04-01

The knee replacement is the second most common orthopedic surgical intervention in the United States, but currently only 1 in 5 knee replacement patients are satisfied with their level of pain reduction one year after surgery. It is imperative to make the process of knee replacement surgery more objective by developing a data driven approach to ligamentous balance, which increases implant life. In this work, piezoelectric materials are considered for both sensing and energy harvesting applications in total knee replacement implants. This work aims to embed piezoelectric material in the polyethylene bearing of a knee replacement unit to act as self-powered sensors that will aid in the alignment and balance of the knee replacement by providing intraoperative feedback to the surgeon. Postoperatively, the piezoelectric sensors can monitor the structural health of the implant in order to perceive potential problems before they become bothersome to the patient. Specifically, this work will present on the use of finite element modeling coupled with uniaxial compression testing to prove that piezoelectric stacks can be utilized to harvest sufficient energy to power sensors needed for this application.

TOTAL KNEE REPLACEMENT IN PATIENTS WITH BELOW-KNEE AMPUTATION

PubMed Central

Karam, Matthew D; Willey, Michael; Shurr, Donald G

2010-01-01

Total knee replacement (TKR) is reserved for patients with severe and disabling arthritis that is non-responsive to conservative measures. Based on existing data, total knee replacement is a safe and cost-effective treatment for alleviating pain and improving physical function in patients who do not respond to conservative therapy. Despite the large variation in health status of patients and types of prosthesis implanted, total knee replacement has proven to be a relatively low risk and successful operation. Each year in the United States surgeons perform approximately 300,000 TKR.1 Likewise, lower extremity amputation is commonly performed in the United States with an annual incidence of 110,000 per year.2 Nearly 70% of all lower extremity amputations are performed as the result of chronic vascular disease, followed by trauma (22%), congenital etiology and tumor (4% each).3 Approximately 50% of all lower extremity amputations are performed secondary to complications from Diabetes Mellitus. Norvell et al. demonstrated that patients who have previously undergone transtibial amputation and ambulate with a prosthesis are more likely to develop degenerative joint disease in the con-tralateral extremity than the ipsilateral extremity.4 Further, radiographic changes consistent with osteoporosis have been demonstrated in up to 88% of limbs that have undergone transtibial amputation.8 To our knowledge, there have been only three reported cases of total knee replacement in patients with ipsilateral transtibial amputation.5,7 The purpose of the present study is to review the existing data on total knee replacement in patients who have undergone transtibial amputation. Further we present a patient with a transtibial amputation who underwent contralateral total knee replacement. PMID:21045987

Prosthetic knee design by simulation

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

Hollerbach, K; Hollister, A

1999-07-30

Although 150,000 total knee replacement surgeries are performed annually in North America, current designs of knee prostheses have mechanical problems that include a limited range of motion, abnormal gait patterns, patellofemoral joint dysfunction, implant loosening or subsidence, and excessive wear. These problems fall into three categories: failure to reproduce normal joint kinematics, which results in altered limb function; bone-implant interface failure; and material failure. Modern computer technology can be used to design, prototype, and test new total knee implants. The design team uses the full range of CAD-CAM to design and produce implant prototypes for mechanical and clinical testing. Closermore » approximation of natural knee kinematics and kinetics is essential for improved patient function and diminished implant loads. Current knee replacement designs are based on 19th Century theories that the knee moves about a variable axis of rotation. Recent research has shown, however, that knee motion occurs about two fixed, offset axes of rotation. These aces are not perpendicular to the long axes of the bones or to each other, and the axes do not intersect. Bearing surfaces of mechanisms that move about axes of rotation are surfaces of revolution of those axes which advanced CAD technology can produce. Solids with surfaces of revolution for the two axes of rotation for the knee have been made using an HP9000 workstation and Structural Ideas Master Series CAD software at ArthroMotion. The implant's CAD model should closely replicate movements of the normal knee. The knee model will have a range of flexion-extension (FE) from -5 to 120 degrees. Movements include varus, valgus, internal and external rotation, as well as flexion and extension. The patellofemoral joint is aligned perpendicular to the FE axis and replicates the natural joint more closely than those of existing prostheses. The bearing surfaces will be more congruent than current designs and should

Differences in knee joint kinematics and forces after posterior cruciate retaining and stabilized total knee arthroplasty.

PubMed

Wünschel, Markus; Leasure, Jeremi M; Dalheimer, Philipp; Kraft, Nicole; Wülker, Nikolaus; Müller, Otto

2013-12-01

Posterior cruciate ligament (PCL) retaining (CR) and -sacrificing (PS) total knee arthroplasties (TKA) are widely-used to treat osteoarthritis of the knee joint. The PS design substitutes the function of the PCL with a cam-spine mechanism which may produce adverse changes to joint kinematics and kinetics. CR- and PS-TKA were performed on 11 human knee specimens. Joint kinematics were measured with a dynamic knee simulator and motion tracking equipment. In-situ loads of the PCL and cam-spine were measured with a robotic force sensor system. Partial weight bearing flexions were simulated and external forces were applied. The PS-TKA rotated significantly less throughout the whole flexion range compared to the CR-TKA. Femoral roll back was greater in the PS-TKA; however, this was not correlated with lower quadriceps forces. Application of external loads produced significantly different in-situ force profiles between the TKA systems. Our data demonstrate that the PS-design significantly alters kinematics of the knee joint. Our data also suggest the cam-spine mechanism may have little influence on high flexion kinematics (such as femoral rollback) with most of the load burden shared by supporting implant and soft-tissue structures. Copyright © 2013 Elsevier B.V. All rights reserved.

A comparison between electromechanical and pneumatic-controlled knee simulators for the investigation of wear of total knee replacements.

PubMed

Abdelgaied, Abdellatif; Fisher, John; Jennings, Louise M

2017-07-01

More robust preclinical experimental wear simulation methods are required in order to simulate a wider range of activities, observed in different patient populations such as younger more active patients, as well as to fully meet and be capable of going well beyond the existing requirements of the relevant international standards. A new six-station electromechanically driven simulator (Simulation Solutions, UK) with five fully independently controlled axes of articulation for each station, capable of replicating deep knee bending as well as other adverse conditions, which can be operated in either force or displacement control with improved input kinematic following, has been developed to meet these requirements. This study investigated the wear of a fixed-bearing total knee replacement using this electromechanically driven fully independent knee simulator and compared it to previous data from a predominantly pneumatically controlled simulator in which each station was not fully independently controlled. In addition, the kinematic performance and the repeatability of the simulators have been investigated and compared to the international standard requirements. The wear rates from the electromechanical and pneumatic knee simulators were not significantly different, with wear rates of 2.6 ± 0.9 and 2.7 ± 0.9 mm 3 /million cycles (MC; mean ± 95% confidence interval, p = 0.99) and 5.4 ± 1.4 and 6.7 ± 1.5 mm 3 /MC (mean ± 95 confidence interval, p = 0.54) from the electromechanical and pneumatic simulators under intermediate levels (maximum 5 mm) and high levels (maximum 10 mm) of anterior-posterior displacements, respectively. However, the output kinematic profiles of the control system, which drive the motion of the simulator, followed the input kinematic profiles more closely on the electromechanical simulator than the pneumatic simulator. In addition, the electromechanical simulator was capable of following kinematic

Total knee arthroplasty after high tibial osteotomy. A comparison study in patients who had bilateral total knee replacement.

PubMed

Meding, J B; Keating, E M; Ritter, M A; Faris, P M

2000-09-01

The outcome of total knee replacement after high tibial osteotomy remains uncertain. We hypothesized that the results of total knee replacement with or without a previous high tibial osteotomy are similar. The results of a consecutive series of thirty-nine bilateral total knee arthroplasties performed with cement at an average of 8.7 years after unilateral high tibial osteotomy were reviewed. There were twenty-seven men and twelve women. Preoperatively, the knee scores according to the system of the Knee Society were similar for all of the knees; however, valgus alignment and patella infera were more common in the knees with a previous high tibial osteotomy. Bilateral total knee replacement was staged in seven patients and was simultaneous in thirty-two patients. The results of the total knee arthroplasties were retrospectively reviewed with respect to the knee and function scores according to the system of the Knee Society, the radiographic findings, and the complications. Intraoperatively, no notable differences were identified in the number of medial, lateral, or lateral patellar releases required. However, less lateral tibial bone was resected in the group with a previous high tibial osteotomy (average, 3.3 millimeters) than in the group without a high tibial osteotomy (average, 7.5 millimeters). The average duration of follow-up was 7.5 years (range, three to sixteen years) in the group with a previous high tibial osteotomy and 6.8 years (range, two to ten years) in the group without a high tibial osteotomy. At the time of the final follow-up, the knee and function scores were similar for the two groups (89.0 and 81.0 points, respectively, for the group with a previous high tibial osteotomy, and 89.6 and 83.9 points, respectively, for the group without a high tibial osteotomy). Although more knees were free of pain in the group without a previous high tibial osteotomy (thirty-six) than in the group with a previous osteotomy (thirty-three), this difference was

Fixation of periprosthetic femur fractures above total knee arthroplasty with the less invasive stabilization system: a midterm follow-up study.

PubMed

Kolb, Werner; Guhlmann, Hanno; Windisch, Christoph; Marx, Frank; Koller, Heiko; Kolb, Klaus

2010-09-01

The complication rate of periprosthetic femoral fractures above well-fixed total knee arthroplasties is high. The Less Invasive Stabilization System (LISS) was introduced to reduce surgical dissections at the fracture site. The purpose of this retrospective study was to evaluate the midterm functional outcome of a group of patients with periprosthetic fractures above well-fixed total knee arthroplasties treated with the LISS. Between January 1999 and June 2004, 23 consecutive patients (all women) with periprosthetic fractures above well-fixed total knee arthroplasties were treated with the LISS. The mean age was 77 years (range, 61-90 years). Nineteen of the patients (83%) were seen after a midterm follow-up of 46 months (range, 26-67 months). Three patients (13%) died, and one patient (4%) was lost to follow-up. A proximal screw pull-out of the internal fixator occurred in one patient (4%). All fractures healed within a mean of 14 weeks (range, 9-21 weeks). No bone graft was required. There were two delayed unions, no nonunions or infections. One patient (4%) had a malalignment with 7° varus. The mean range of motion was 102° (range, 65-120°). The mean knee score of the Knee Society was 81 points (range, 65-90 points), and the mean function score of the Knee Society was 56 points (range, 35-90 points). We found that a minimally invasive, locked plating system permitted stable fixation, early knee motion with good midterm results, and minimal complications. These techniques should be used in place of less stable and more invasive methods.

Cross-sectional and Longitudinal Associations between Knee Joint Effusion Synovitis and Knee Pain in Older Adults.

PubMed

Wang, Xia; Jin, Xingzhong; Han, Weiyu; Cao, Yuelong; Halliday, Andrew; Blizzard, Leigh; Pan, Faming; Antony, Benny; Cicuttini, Flavia; Jones, Graeme; Ding, Changhai

2016-01-01

To describe the cross-sectional and longitudinal associations between knee regional effusion synovitis and knee pain in older adults. Data from a population-based random sample (n = 880, mean age 62 yrs, 50% women) were used. Baseline knee joint effusion synovitis was graded (0-3) using T2-weighted magnetic resonance imaging (MRI) in the suprapatellar pouch, central portion, posterior femoral recess, and subpopliteal recess. Effusion synovitis of the whole joint was defined as a score of ≥ 2 in any subregion. Other knee structural (including cartilage, bone marrow, and menisci) lesions were assessed by MRI at baseline. Knee pain was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire at baseline and 2.6 years later. Multivariable analyses were performed after adjustment for age, sex, body mass index, and other structural lesions. The prevalence of effusion synovitis was 67%. Suprapatellar pouch effusion synovitis was significantly and independently associated with increased total and nonweight-bearing knee pain in both cross-sectional and longitudinal analyses (for an increase in total knee pain of ≥ 5, RR 1.26 per grade, 95% CI 1.04-1.52), and increased weight-bearing knee pain in longitudinal analysis only. Effusion synovitis in posterior femoral recess and central portion were independently associated with increases in nonweight-bearing pain (RR 1.63 per grade, 95% CI 1.32-2.01 and RR 1.29 per grade, 95% CI 1.01-1.65, respectively) in longitudinal analyses only. Knee joint effusion synovitis has independent associations with knee pain in older adults. Suprapatellar pouch effusion synovitis is associated with nonweight-bearing and weight-bearing knee pain, while posterior femoral recess and central portion effusion synovitis are only associated with nonweight-bearing pain.

In vivo anteroposterior translation after meniscal-bearing total knee arthroplasty: effects of soft tissue conditions and flexion angle.

PubMed

Ishii, Yoshinori; Noguchi, Hideo; Takeda, Mitsuhiro; Sato, Junko; Sakurai, Tetsuya; Toyabe, Shin-Ichi

2014-08-01

Anteroposterior (AP) joint translation is an important indicator of good clinical outcome following total knee arthroplasty (TKA). This study evaluated the in vivo relationship between changes in the degree of voluntary soft tissue tension and flexion angle versus simultaneous AP translation after TKA. A posterior cruciate ligament (PCL)-retaining meniscal-bearing design was investigated in 20 knees of 20 patients. AP translation was measured at 30° and 75° flexion with the KT-2000 arthrometer while patients were anesthetized and non-anesthetized. The mean translations at 30° and 75° were 10.5 and 10.4 mm, respectively, in non-anesthetized patients and 13.8 and 12.7 mm, respectively, in patients under anesthesia. AP translation showed a significant positive correlation with soft tissue tension (p < 0.001), but not with flexion angle (p = 0.366). No interaction was observed between soft tissue tension and the flexion angle in terms of AP translation (p = 0.431). Surgeons should recognize that AP translation is greater in anesthetized patients than in non-anesthetized patients, regardless of the flexion angle, with no significant correlation between flexion angle and translation, regardless of the level of consciousness. Because conformity between the tibial insert and femoral component decreases with flexion, whereas the opposing effects of supporting structures, such as muscles, ligaments, and capsules, increases, proper soft tissue tension, particularly retention of a functional PCL, could have an important role in determining AP translation in the current prosthesis design.

Total knee arthroplasty in limbs affected by poliomyelitis.

PubMed

Giori, Nicholas J; Lewallen, David G

2002-07-01

Little information is available regarding the results and complications of total knee arthroplasty in limbs affected by poliomyelitis with severe knee degeneration. We performed a retrospective chart and radiograph review of patients with a history of poliomyelitis involving a limb that subsequently underwent primary total knee arthroplasty between 1970 and 2000. Sixteen total knee arthroplasties were performed in limbs affected by poliomyelitis in fifteen patients. Eleven patients were followed for a minimum of two years, one (two knees) died before the minimum two-year follow-up could be completed, and three were followed for less than two years. No patient was lost to follow-up. There were two periprosthetic fractures, one peroneal nerve palsy, one avulsion of the patellar tendon, and four cases of recurrent instability. These complications were related to the poor bone quality, valgus deformity, patella baja, poor musculature, and attenuated soft tissues commonly found in knees affected by poliomyelitis. Knee Society pain and knee scores were improved postoperatively for all nine knees with a two-year follow-up that had had at least antigravity quadriceps strength prior to surgery. However, Knee Society function scores remained at 0 or worsened for six of the eleven knees followed for at least two years, including those with less than antigravity strength, and four of the nine knees with at least antigravity strength. None of the prostheses loosened. Pain and knee scores improved following total knee arthroplasty in patients with a history of poliomyelitis and antigravity quadriceps strength, but there was less pain relief in patients with less than antigravity quadriceps strength. Recurrence of instability and progressive functional deterioration is possible in all knees affected by poliomyelitis that have undergone total knee replacement, but they appear to occur more commonly in more severely affected knees.

Failure of aseptic revision total knee arthroplasties

PubMed Central

Leta, Tesfaye H; Lygre, Stein Håkon L; Skredderstuen, Arne; Hallan, Geir; Furnes, Ove

2015-01-01

Background and purpose In Norway, the proportion of revision knee arthroplasties increased from 6.9% in 1994 to 8.5% in 2011. However, there is limited information on the epidemiology and causes of subsequent failure of revision knee arthroplasty. We therefore studied survival rate and determined the modes of failure of aseptic revision total knee arthroplasties. Method This study was based on 1,016 aseptic revision total knee arthroplasties reported to the Norwegian Arthroplasty Register between 1994 and 2011. Revisions done for infections were not included. Kaplan-Meier and Cox regression analyses were used to assess the survival rate and the relative risk of re-revision with all causes of re-revision as endpoint. Results 145 knees failed after revision total knee arthroplasty. Deep infection was the most frequent cause of re-revision (28%), followed by instability (26%), loose tibial component (17%), and pain (10%). The cumulative survival rate for revision total knee arthroplasties was 85% at 5 years, 78% at 10 years, and 71% at 15 years. Revision total knee arthroplasties with exchange of the femoral or tibial component exclusively had a higher risk of re-revision (RR = 1.7) than those with exchange of the whole prosthesis. The risk of re-revision was higher for men (RR = 2.0) and for patients aged less than 60 years (RR = 1.6). Interpretation In terms of implant survival, revision of the whole implant was better than revision of 1 component only. Young age and male sex were risk factors for re-revision. Deep infection was the most frequent cause of failure of revision of aseptic total knee arthroplasties. PMID:25267502

[CORRECTION OF VARUS KNEE WITH REDUCTION OSTEOTOMY DURING TOTAL KNEE ARTHROPLASTY].

PubMed

Su, Weiping; Xie, Jie; Li, Mingqing; Zeng, Min; Lei, Pengfei; Wang, Long; Hu, Yihe

2015-12-01

To evaluate the effectiveness of reduction osteotomy for correction of varus knee during total knee arthroplasty. A retrospective analysis was made on the clinical data of 16 patients (24 knees) who received reduction osteotomy for correcting varus knee during total knee arthroplasty between May 2010 and July 2012. There were 2 males (3 knees) and 14 females (21 knees), with an average age of 67 years (range, 57-79 years). The disease duration ranged from 3 to 15 years (mean, 9.1 years). The Knee Society Score (KSS) was 38.71 ± 10.04 for clinical score and 50.31 ± 14.31 for functional score. The range of motion (ROM) of the knee was (91.88 ± 13.01). The tibiofemoral angle was (9.04 ± 4.53)° of varus deformity. Reduction osteotomy was applied to correct varus knee. The operation time was 85-245 minutes (mean, 165.5 minutes); the obvious blood loss was 10-800 mL (mean, 183.1 mL); the hospitalization time was 8-22 days (mean, 13.6 days). All incisions healed by first intention. No neurovascular injury or patellar fracture occurred. The follow-up duration ranged from 37 to 62 months (mean, 48 months). The tibiofemoral angle was corrected to (3.92 ± 1.89)° of valgus at 48 hours after operation. The lower limb alignment recovered to normal. The X-ray films showed no evidence of obvious radiolucent line, osteolysis, or prosthesis subsidence. The results of KSS were significantly improved to 84.21 ± 6.49 for clinical score and 85.31 ± 6.95 for functional score (t = 20.665, P = 0.000; t = 9.585, P = 0.000); and ROM of the knee was significantly increased to (105.83 ± 11.29)° (t = 8.333, P = 0.000) at last follow-up. The effectiveness of reduction osteotomy for varus knee deformity during total knee arthroplasty is satisfactory. Proper alignment, ROM, and function of knee can be achieved.

Influence of bi- and tri-compartmental knee arthroplasty on the kinematics of the knee joint.

PubMed

Wünschel, Markus; Lo, Jiahsuan; Dilger, Torsten; Wülker, Nikolaus; Müller, Otto

2011-01-27

The cruciate ligaments are important stabilizers of the knee joint and determine joint kinematics in the natural knee and after cruciate retaining arthroplasty.No in vitro data is available to biomechanically evaluate the ability of the anterior cruciate ligament (ACL) to maintain knee joint kinematics after bicruciate-retaining bi-compartmental knee arthroplasty (BKA).Therefore, the objective of the current study was to investigate the kinematics of the natural knee joint, before and after installing bicruciate-retaining BKA and posterior cruciate retaining total knee arthroplasty. Specifically, we incorporated a dynamic knee simulator to simulate weight-bearing flexions on cadaveric knee specimen before and after surgical manipulations. In this cadaveric study we investigated rotational and translational tibiofemoral kinematics during simulated weight-bearing flexions of the intact knee, after bi-compartmental knee arthroplasty (BKA+), after resecting the ACL in BKA (BKA-), and after posterior cruciate retaining total knee arthroplasty (TKA). Rotation of BKA+ is closest to the intact knee joint, whereas TKA shows significant differences from 30 to 90 degree of flexion. Within the tested flexion range (15 to 90 degree of flexion), there was no significant difference in the anterior-posterior translation among intact, BKA+, and TKA knees. Resecting the ACL in BKA leads to a significant anterior tibial translation. BKA with intact cruciate ligaments resembles rotation and translation of the natural knee during a simulated weight-bearing flexion. It is a suitable treatment option for medial and patellofemoral osteoarthritis with advantages in rotational characteristics compared to TKA.

Spaceflight-Relevant Challenges of Radiation and/or Reduced Weight Bearing Cause Arthritic Responses in Knee Articular Cartilage.

PubMed

Willey, J S; Kwok, A T; Moore, J E; Payne, V; Lindburg, C A; Balk, S A; Olson, J; Black, P J; Walb, M C; Yammani, R R; Munley, M T

2016-10-01

There is little known about the effect of both reduced weight bearing and exposure to radiation during spaceflight on the mechanically-sensitive cartilage lining the knee joint. In this study, we characterized cartilage damage in rat knees after periods of reduced weight bearing with/without exposure to solar-flare-relevant radiation, then cartilage recovery after return to weight bearing. Male Sprague Dawley rats (n = 120) were either hindlimb unloaded (HLU) via tail suspension or remained weight bearing in cages (GROUND). On day 5, half of the HLU and GROUND rats were 1 Gy total-body X-ray irradiated during HLU, and half were sham irradiated (SHAM), yielding 4 groups: GROUND-SHAM; GROUND-IR; HLU-SHAM; and HLU-IR. Hindlimbs were collected from half of each group of rats on day 13. The remaining rats were then removed from HLU or remained weight bearing, and hindlimbs from these rats were collected on day 62. On day 13, glycosaminoglycan (GAG) content in cartilage lining the tibial plateau and femoral condyles of HLU rats was lower than that of the GROUND animals. Likewise, on day 13, immunoreactivity of the collagen type II-degrading matrix metalloproteinase-13 (MMP-13) and of a resultant metalloproteinase-generated neoepitope VDIPEN was increased in all groups versus GROUND-SHAM. Clustering of chondrocytes indicating cartilage damage was present in all HLU and IR groups versus GROUND-SHAM on day 13. On day 62, after 49 days of reloading, the loss of GAG content was attenuated in the HLU-SHAM and HLU-IR groups, and the increased VDIPEN staining in all treatment groups was attenuated. However, the increased chondrocyte clustering remained in all treatment groups on day 62. MMP-13 activity also remained elevated in the GROUND-IR and HLU-IR groups. Increased T2 relaxation times, measured on day 62 using 7T MRI, were greater in GROUND-IR and HLU-IR knees, indicating persistent cartilage damage in the irradiated groups. Both HLU and total-body irradiation resulted in

Effect of knee joint icing on knee extension strength and knee pain early after total knee arthroplasty: a randomized cross-over study.

PubMed

Holm, Bente; Husted, Henrik; Kehlet, Henrik; Bandholm, Thomas

2012-08-01

To investigate the acute effect of knee joint icing on knee extension strength and knee pain in patients shortly after total knee arthroplasty. A prospective, single-blinded, randomized, cross-over study. A fast-track orthopaedic arthroplasty unit at a university hospital. Twenty patients (mean age 66 years; 10 women) scheduled for primary unilateral total knee arthroplasty. The patients were treated on two days (day 7 and day 10) postoperatively. On one day they received 30 minutes of knee icing (active treatment) and on the other day they received 30 minutes of elbow icing (control treatment). The order of treatments was randomized. Maximal knee extension strength (primary outcome), knee pain at rest and knee pain during the maximal knee extensions were measured 2-5 minutes before and 2-5 minutes after both treatments by an assessor blinded for active or control treatment. The change in knee extension strength associated with knee icing was not significantly different from that of elbow icing (knee icing change (mean (1 SD)) -0.01 (0.07) Nm/kg, elbow icing change -0.02 (0.07) Nm/kg, P = 0.493). Likewise, the changes in knee pain at rest (P = 0.475), or knee pain during the knee extension strength measurements (P = 0.422) were not different between treatments. In contrast to observations in experimental knee effusion models and inflamed knee joints, knee joint icing for 30 minutes shortly after total knee arthroplasty had no acute effect on knee extension strength or knee pain.

The Survival of Total Knee Arthroplasty: Current Data from Registries on Tribology: Review Article.

PubMed

Civinini, Roberto; Carulli, Christian; Matassi, Fabrizio; Lepri, Andrea Cozzi; Sirleo, Luigi; Innocenti, Massimo

2017-02-01

Polyethylene (PE) wear is a major contributor to implant loosening following total knee arthroplasty (TKA), and advanced bearings in TKA are being investigated with hopes of reducing or eliminate wear-related loosening. Currently, information on knee tribology is available from national joint registries and may be the best tools to evaluate the efficacy and safety of design innovations in joint arthroplasty. We performed a review of national joint registries trying to answer the following questions: "Which is the main factor directly related to revisions rate in TKA?" and "Are there new bearing options better than conventional ones?" A review was performed of all published annual reports of National Joint Registers, as well as of the literature. The search was carried out using and comparing the National Joint Registers. Current data from registries for total knee arthroplasty indicates that age is the major factor affecting the outcome of primary total knee replacement. The 10-year cumulative revision rate for non-cross-linked PE was 5.8% and for XLPE it was 3.5%. The effect of cross-linked polyethylene was more evident in the younger patients. The survival of the oxidized zirconium (OxZr) femoral component appears better when compared to a similar age group of patients with conventional group of prostheses. Our review suggests that the revision rates are half for the OxZr components compared to conventional CoCr femoral components. Age is the most relevant single factor related to revision rate. Cross-linked PE has a statistical lower revision rate at 10 years compared to conventional PE and, in the OxZr group, the revision rate is 2 times lower than Co-Cr in the same group of age.

A comparison between electromechanical and pneumatic-controlled knee simulators for the investigation of wear of total knee replacements

PubMed Central

Abdelgaied, Abdellatif; Fisher, John; Jennings, Louise M

2017-01-01

More robust preclinical experimental wear simulation methods are required in order to simulate a wider range of activities, observed in different patient populations such as younger more active patients, as well as to fully meet and be capable of going well beyond the existing requirements of the relevant international standards. A new six-station electromechanically driven simulator (Simulation Solutions, UK) with five fully independently controlled axes of articulation for each station, capable of replicating deep knee bending as well as other adverse conditions, which can be operated in either force or displacement control with improved input kinematic following, has been developed to meet these requirements. This study investigated the wear of a fixed-bearing total knee replacement using this electromechanically driven fully independent knee simulator and compared it to previous data from a predominantly pneumatically controlled simulator in which each station was not fully independently controlled. In addition, the kinematic performance and the repeatability of the simulators have been investigated and compared to the international standard requirements. The wear rates from the electromechanical and pneumatic knee simulators were not significantly different, with wear rates of 2.6 ± 0.9 and 2.7 ± 0.9 mm3/million cycles (MC; mean ± 95% confidence interval, p = 0.99) and 5.4 ± 1.4 and 6.7 ± 1.5 mm3/MC (mean ± 95 confidence interval, p = 0.54) from the electromechanical and pneumatic simulators under intermediate levels (maximum 5 mm) and high levels (maximum 10 mm) of anterior–posterior displacements, respectively. However, the output kinematic profiles of the control system, which drive the motion of the simulator, followed the input kinematic profiles more closely on the electromechanical simulator than the pneumatic simulator. In addition, the electromechanical simulator was capable of following kinematic and

Higher Rate of Revision in PFC Sigma Primary Total Knee Arthroplasty With Mismatch of Femoro-Tibial Component Sizes.

PubMed

Young, Simon W; Clarke, Henry D; Graves, Stephen E; Liu, Yen-Liang; de Steiger, Richard N

2015-05-01

Total knee arthroplasty (TKA) systems permit a degree of femoro-tibial component size mismatch. The effect of mismatched components on revision rates has not been evaluated in a large study. We reviewed 21,906 fixed-bearing PFC Sigma primary TKAs using the Australian Orthopaedic Association National Joint Replacement Registry, dividing patients into three groups: no femoro-tibial size mismatch, tibial component size > femoral component size, and femoral component > tibial component. Revision rates were higher when the femoral size was greater than the tibia, compared to both equal size (HR = 1.20 (1.00, 1.45), P = 0.047) and to tibial size greater than femoral (HR = 1.60 (1.08, 2.37), P = 0.019). Potential mechanisms to explain these findings include edge loading of polyethylene and increased tibial component stresses. Copyright © 2014 Elsevier Inc. All rights reserved.

Factors predicting weight-bearing asymmetry 1month after unilateral total knee arthroplasty: a cross-sectional study.

PubMed

Christiansen, Cory L; Bade, Michael J; Weitzenkamp, David A; Stevens-Lapsley, Jennifer E

2013-03-01

Factors predicting weight-bearing asymmetry (WBA) after unilateral total knee arthroplasty (TKA) are not known. However, identifying modifiable and non-modifiable predictors of WBA is needed to optimize rehabilitation, especially since WBA is negatively correlated to poor functional performance. The purpose of this study was to identify factors predictive of WBA during sit-stand transitions for people 1month following unilateral TKA. Fifty-nine people were tested preoperatively and 1month following unilateral TKA for WBA using average vertical ground reaction force under each foot during the Five Times Sit-to-Stand Test. Candidate variables tested in the regression analysis represented physical impairments (strength, muscle activation, pain, and motion), demographics, anthropometrics, and movement compensations. WBA, measured as the ratio of surgical/non-surgical limb vertical ground reaction force, was 0.69 (0.18) (mean (SD)) 1month after TKA. Regression analysis identified preoperative WBA (β=0.40), quadriceps strength ratio (β=0.31), and hamstrings strength ratio (β=0.19) as factors predictive of WBA 1month after TKA (R(2)=0.30). Greater amounts of WBA 1month after TKA are predicted by modifiable factors including habitual movement pattern and asymmetry in quadriceps and hamstrings strength. Copyright © 2012 Elsevier B.V. All rights reserved.

Influence of bi- and tri-compartmental knee arthroplasty on the kinematics of the knee joint

PubMed Central

2011-01-01

Background The cruciate ligaments are important stabilizers of the knee joint and determine joint kinematics in the natural knee and after cruciate retaining arthroplasty. No in vitro data is available to biomechanically evaluate the ability of the anterior cruciate ligament (ACL) to maintain knee joint kinematics after bicruciate-retaining bi-compartmental knee arthroplasty (BKA). Therefore, the objective of the current study was to investigate the kinematics of the natural knee joint, before and after installing bicruciate-retaining BKA and posterior cruciate retaining total knee arthroplasty. Specifically, we incorporated a dynamic knee simulator to simulate weight-bearing flexions on cadaveric knee specimen before and after surgical manipulations. Methods In this cadaveric study we investigated rotational and translational tibiofemoral kinematics during simulated weight-bearing flexions of the intact knee, after bi-compartmental knee arthroplasty (BKA+), after resecting the ACL in BKA (BKA-), and after posterior cruciate retaining total knee arthroplasty (TKA). Results Rotation of BKA+ is closest to the intact knee joint, whereas TKA shows significant differences from 30 to 90 degree of flexion. Within the tested flexion range (15 to 90 degree of flexion), there was no significant difference in the anterior-posterior translation among intact, BKA+, and TKA knees. Resecting the ACL in BKA leads to a significant anterior tibial translation. Conclusions BKA with intact cruciate ligaments resembles rotation and translation of the natural knee during a simulated weight-bearing flexion. It is a suitable treatment option for medial and patellofemoral osteoarthritis with advantages in rotational characteristics compared to TKA. PMID:21272328

Revision of Unicondylar to Total Knee Arthroplasty: A Systematic Review

PubMed Central

Siddiqui, Nashat A; Ahmad, Zafar M

2012-01-01

Isolated unicompartmental osteoarthritis in the young patient is a difficult problem to treat; they may be too young to consider total knee arthroplasty due to difficulties with inevitable future revision. Unicompartmental knee arthroplasty is one possible solution as it is perceived by some as being a smaller surgical insult than total knee arthroplasty, with easier revision to total knee arthroplasty than a revision total knee arthroplasty. A total knee arthroplasty performed as a revision unicondylar knee arthroplasty is thought by some authors to have equivalent functional outcomes to a primary total knee replacement. However, there have been several studies suggesting that revision is not as simple as suggested, and that function is not as good as primary total knee arthroplasty. We performed a systematic review of the literature regarding outcomes after revision of a unicondylar knee arthroplasty. Although there are many studies proposing selective use of the unicondylar knee arthroplasty, there are a number of studies highlighting difficulties with revision and poorer outcomes, and, therefore, the unicondylar knee arthroplasty cannot be considered a small procedure that will 'buy time' for the patient, and have results equal to a primary knee arthroplasty when revised. Further controlled studies, ideally randomised, are required before final conclusions can be drawn. PMID:22905072

Total knee arthroplasty in patients with a previous patellectomy.

PubMed

Maslow, Jed; Zuckerman, Joseph D; Immerman, Igor

2013-01-01

Post-patellectomy patients represent a specific subgroup of patients that may develop arthritis and persistent knee pain and potentially require treatment with total knee arthroplasty. This article reviews the treatment and functional outcomes following total knee arthroplasty in patients with prior patellectomy. A case report is presented as an example of the clinical management of a post-patellectomy patient with significant knee pain and disability treated with total knee arthroplasty. Emphasis will be placed in decision- making, specifically with the use of a posterior stabilized implant. In addition, postoperative strengthening of the quadriceps is essential to compensate for the lack of the patella and increase the success of total knee arthroplasty in this subgroup of patients.

Elongation of the collateral ligaments after cruciate retaining total knee arthroplasty and the maximum flexion of the knee.

PubMed

Park, Kwan Kyu; Hosseini, Ali; Tsai, Tsung-Yuan; Kwon, Young-Min; Li, Guoan

2015-02-05

The mechanisms that affect knee flexion after total knee arthroplasty (TKA) are still debatable. This study investigated the elongation of the superficial medial (sMCL) and lateral collateral ligaments (LCL) before and after a posterior cruciate retaining (CR) TKA. We hypothesized that overstretching of the collateral ligaments in high flexion after TKA could reduce maximal flexion of the knee. Three-dimensional models of 11 osteoarthritic knees of 11 patients including the insertions of the collateral ligaments were created using MR images. Each ligament was divided into three equal portions: anterior, middle and posterior portions. The shortest 3D wrapping length of each ligament portion was determined before and after the TKA surgery along a weight-bearing, single leg flexion path. The relationship between the changes of ligament elongation and the changes of the maximal knee flexion after TKAs was quantitatively analyzed. The sMCL showed significant increases in length only at low flexion after TKA; the LCL showed decreases in length at full extension, but increases with further flexion after TKA. The amount of increases of the maximum flexion angle after TKA was negatively correlated with the increases of the elongations of the anterior portion (p=0.010, r=0.733) and middle portion (p=0.049, r=0.604) of the sMCL as well as the anterior portion (p=0.010, r=0.733) of the LCL at maximal flexion of the knee. The results indicated that the increases of the length of the collateral ligaments at maximal flexion after TKA were associated with the decreases of the maximal flexion of the knee. Our data suggest that collateral ligament management should also be evaluated at higher knee flexion angles in order to optimize maximal flexion of the knee after TKAs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bearing Dislocation and Progression of Osteoarthritis After Mobile-bearing Unicompartmental Knee Arthroplasty Vary Between Asian and Western Patients: A Meta-analysis.

PubMed

Ro, Kyung-Han; Heo, Jae-Won; Lee, Dae-Hee

2018-05-01

estimations using the restricted maximum likelihood method. There was no difference in the proportion of Asian patients versus Western patients undergoing reoperation for any cause calculated as 100 component observed years (1.022 of 3152 Asian patients; 95% CI, 0.810-1.235 versus 1.300 of 5455 Western patients; 95% CI, 1.067-1.534; odds ratio, 0.7839; 95% CI, 0.5323-1.1545; p = 0.178). The mean reoperation rate attributable to bearing dislocation per 100 observed years was higher in Asian than in Western patients (0.525; 95% CI, 0.407-0.643 versus 0.141; 95% CI, 0.116-0.166; odds ratio, 3.7378; 95% CI, 1.694-8.248; p = 0.001) Conversely, the mean reoperation rate attributable to lateral knee OA per 100 observed years was lower in Asian than in Western patients (0.093; 95% CI, 0.070-0.115 versus 0.298; 95% CI, 0.217-0.379; odds ratio, 0.3114; 95% CI, 0.0986-0.9840; p < 0.001). Although total reoperation rates did not differ in the two populations, reoperation for bearing dislocation was more likely to occur in Asian than in Western patients, whereas reoperation for lateral knee OA progression was more likely to occur in Western than in Asian patients after Oxford Phase III UKA. Although possible explanations for these findings may be hypothesized, additional randomized, prospective comparative studies are needed. However, better survival outcomes after UKA may require consideration of ethnicity and lifestyle choices in addition to traditional surgical technique and perioperative care. Level III, therapeutic study.

One Stage Conversion of an Infected Fused Knee to Total Knee Replacement - A Surgical Challenge

PubMed Central

Ravikumar, Mukartihal; Kendoff, Daniel; Citak, Mustafa; Luck, Stefan; Gehrke, Thorsten; Zahar, Akos

2013-01-01

Background and Purpose: Two-stage revision arthroplasty is a common technique for the treatment of infected total knee replacement. Few reports have addressed the conversion of a fused knee into a total knee replacement. However, there is no case reported of converting an infected fused knee into a hinge knee using a one-stage procedure. Methods: We report on a 51-year old male patient with an infected fused knee after multiple surgeries. Results and Interpretation: A one-stage conversion of septic fused knee into total knee arthroplasty by a rotational hinge prosthesis was performed. The case highlights that with profound preoperative assessment, meticulous surgical technique, combined antibiotic treatment and the right implant, one-stage revision in a surgical challenge may have a role as a treatment option with good functional outcome. PMID:23526706

Soft tissue knee contracture of the knee due to melorheostosis, treated by total knee arthroplasty.

PubMed

Moulder, Elizabeth; Marsh, Clayton

2006-10-01

Melorheostosis is a rare condition which can cause soft tissue joint contractures. We present a case of melorheostosis causing disabling knee joint contracture, treated successfully by total knee arthroplasty.

Development and evaluation of an instrumented linkage system for total knee surgery.

PubMed

Walker, Peter S; Wei, Chih-Shing; Forman, Rachel E; Balicki, M A

2007-10-01

The principles and application of total knee surgery using optical tracking have been well demonstrated, but electromagnetic tracking may offer further advantages. We asked whether an instrumented linkage that attaches directly to the bone can maintain the accuracy of the optical and electromagnetic systems but be quicker, more convenient, and less expensive to use. Initial testing using a table-mounted digitizer to navigate a drill guide for placing pins to mount a cutting guide demonstrated the feasibility in terms of access and availability. A first version (called the Mark 1) instrumented linkage designed to fix directly to the bone was constructed and software was written to carry out a complete total knee replacement procedure. The results showed the system largely fulfilled these goals, but some surgeons found that using a visual display for pin placement was difficult and time consuming. As a result, a second version of a linkage system (called the K-Link) was designed to further develop the concept. User-friendly flexible software was developed for facilitating each step quickly and accurately while the placement of cutting guides was facilitated. We concluded that an instrumented linkage system could be a useful and potentially lower-cost option to the current systems for total knee replacement and could possibly have application to other surgical procedures.

Total knee arthroplasty for severe valgus knee deformity.

PubMed

Zhou, Xinhua; Wang, Min; Liu, Chao; Zhang, Liang; Zhou, Yixin

2014-01-01

Primary total knee arthroplasty (TKA) in severe valgus knees may prove challenging, and choice of implant depends on the severity of the valgus deformity and the extent of soft-tissue release. The purpose of this study was to review 8 to 11 years (mean, 10 years) follow-up results of primary TKA for varient-III valgus knee deformity with use of different type implants. Between January 2002 and January 2005, 20 women and 12 men, aged 47 to 63 (mean, 57.19 ± 6.08) years old, with varient-III valgus knees underwent primary TKA. Of the 32 patients, 37 knees had varient-III deformities. Pie crusting was carefully performed with small, multiple inside-out incisions, bone resection balanced the knee in lieu of soft tissue releases that were not used in the series. Cruciate-retaining knees (Gemini MKII, Link Company, Germany) were used in 13 knees, Genesis II (Simth & Nephew Company, USA) in 14 knees, and hinged knee (Endo-Model Company, Germany) in 10 knees. In five patients with bilateral variant-III TKAs, three patients underwent 1-stage bilateral procedures, and two underwent 2-stage procedures. All implants were cemented and the patella was not resurfaced. The Hospital for Special Surgery (HSS) knee score was assessed. Patients were followed up from 8 to 11 years. The mean HSS knee score were improved from 50.33 ± 11.60 to 90.06 ± 3.07 (P < 0.001). The mean tibiofemoral alignment were improved from valgus 32.72° ± 9.68° pre-operation to 4.89° ± 0.90° post-operation (P < 0.001). The mean range of motion were improved from 93.72° ± 23.69° pre-operation to 116.61 ± 16.29° post-operation (P < 0.001). No patients underwent revision. One patient underwent open reduction and internal fixation using femoral condylar plates for supracondylar femoral fractures secondary to a fall at three years. Three patients developed transient peroneal nerve palsies, which resolved within nine months. Two patients developed symptomatic deep vein thrombosis that was managed with

Posterior stabilized versus cruciate retaining total knee arthroplasty designs: conformity affects the performance reliability of the design over the patient population.

PubMed

Ardestani, Marzieh M; Moazen, Mehran; Maniei, Ehsan; Jin, Zhongmin

2015-04-01

Commercially available fixed bearing knee prostheses are mainly divided into two groups: posterior stabilized (PS) versus cruciate retaining (CR). Despite the widespread comparative studies, the debate continues regarding the superiority of one type over the other. This study used a combined finite element (FE) simulation and principal component analysis (PCA) to evaluate "reliability" and "sensitivity" of two PS designs versus two CR designs over a patient population. Four fixed bearing implants were chosen: PFC (DePuy), PFC Sigma (DePuy), NexGen (Zimmer) and Genesis II (Smith & Nephew). Using PCA, a large probabilistic knee joint motion and loading database was generated based on the available experimental data from literature. The probabilistic knee joint data were applied to each implant in a FE simulation to calculate the potential envelopes of kinematics (i.e. anterior-posterior [AP] displacement and internal-external [IE] rotation) and contact mechanics. The performance envelopes were considered as an indicator of performance reliability. For each implant, PCA was used to highlight how much the implant performance was influenced by changes in each input parameter (sensitivity). Results showed that (1) conformity directly affected the reliability of the knee implant over a patient population such that lesser conformity designs (PS or CR), had higher kinematic variability and were more influenced by AP force and IE torque, (2) contact reliability did not differ noticeably among different designs and (3) CR or PS designs affected the relative rank of critical factors that influenced the reliability of each design. Such investigations enlighten the underlying biomechanics of various implant designs and can be utilized to estimate the potential performance of an implant design over a patient population. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

[Knee arthrodesis performed with intramedullary nailing technique in failed total knee replacement--a preliminary report].

PubMed

Gaździk, Tadeusz Szymon; Kotas-Strzoda, Justyna; Bozek, Marek

2004-01-01

Knee arthrodesis is the method of choice in treatment of failed total knee replacement. It is recommended when revisory total knee replacement is impossible. The authors present 2 cases of knee fusions using intramedullary nails after prosthesis loosening (1 aseptic, 1 septic). In both cases good results were achieved, with no complications observed during convalescence.

Results with nine years mean follow up on one hundred and three KAPS® uni knee arthroplasties: eighty six medial and seventeen lateral.

PubMed

Saragaglia, Dominique; Bevand, Adrien; Refaie, Ramsay; Rubens-Duval, Brice; Pailhé, Régis

2018-05-01

The purpose of this study was to present the results of the KAPS® uni knee arthroplasty system, both mobile and fixed bearing with reference to function, alignment and complications in 103 implants with a mean follow-up of nine years. This was a retrospective study of 103 unicompartimental knee arthroplasties in 89 patients operated on between March 2005 and March 2010. The population was composed of 50 males and 39 females, with a mean age of 70.5 ± 7.5 years (41 - 90). Eighty-seven patients had a genu varum deformity (84.5%), one of whom had an osteoid osteoma of the lateral tibial plateau and 16 patients had a genu valgum (15.5%). Eighty-six medial prostheses were implanted (82 mobile bearings and 4 fixed bearings) and 17 lateral prostheses (all fixed bearings) including the osteoid osteoma. At a mean follow-up of 107.5 months (73-138), 72 knees (58 patients) were reviewed (70%). The mean IKS score was of 173 ± 31 points (58 - 200). The mean Oxford knee score was 21 ± 8 points (12 - 50). The cumulated survival rate at a follow up of 132 months was 98.2%. The KAPS® unicompartmental knee arthroplasty gives efficacious and safe outcomes in the majority of cases at a mean follow-up of nine years. The availability of both fixed and mobile bearings with the same instrumentation, allowing to choose the right implant intra-operatively, is a great advantage in order to avoid the occurrence of some complications, specific to mobile bearing prostheses (dislocation and over-correction).

Cementless total knee arthroplasty

PubMed Central

Risitano, Salvatore; Sabatini, Luigi; Giachino, Matteo; Agati, Gabriele; Massè, Alessandro

2016-01-01

Interest for uncemented total knee arthroplasty (TKA) has greatly increased in recent years. This technique, less used than cemented knee replacement in the last decades, sees a revival thanks an advance in prosthetic design, instrumentation and operative technique. The related literature in some cases shows conflicting data on survival and on the revision’s rate, but in most cases a success rate comparable to cemented TKA is reported. The optimal fixation in TKA is a subject of debate with the majority of surgeons favouring cemented fixation. PMID:27162779

Reduced Operating Time but Not Blood Loss With Cruciate Retaining Total Knee Arthroplasty

PubMed Central

Vermesan, Dinu; Trocan, Ilie; Prejbeanu, Radu; Poenaru, Dan V; Haragus, Horia; Gratian, Damian; Marrelli, Massimo; Inchingolo, Francesco; Caprio, Monica; Cagiano, Raffaele; Tatullo, Marco

2015-01-01

Background There is no consensus regarding the use of retaining or replacing cruciate implants for patients with limited deformity who undergo a total knee replacement. Scope of this paper is to evaluate whether a cruciate sparing total knee replacement could have a reduced operating time compared to a posterior stabilized implant. Methods For this purpose, we performed a randomized study on 50 subjects. All procedures were performed by a single surgeon in the same conditions to minimize bias and only knees with a less than 20 varus deviation and/or maximum 15° fixed flexion contracture were included. Results Surgery time was significantly shorter with the cruciate retaining implant (P = 0.0037). The mean duration for the Vanguard implant was 68.9 (14.7) and for the NexGen II Legacy was 80.2 (11.3). A higher range of motion, but no significant Knee Society Scores at 6 months follow-up, was used as controls. Conclusions In conclusion, both implants had the potential to assure great outcomes. However, if a decision has to be made, choosing a cruciate retaining procedure could significantly reduce the surgical time. When performed under tourniquet, this gain does not lead to reduced blood loss. PMID:25584102

The immediate effect of patellar tendon strap on weight-bearing asymmetry during squatting in patients with unilateral knee osteoarthritis: A pilot study.

PubMed

Demirbüken, İlkşan; Özyürek, Seher; Angın, Salih

2016-12-01

Knee osteoarthritis has commonly been associated with a symptom of pain resulting in an inter-limb weight-bearing asymmetry during functional tasks. Patellar tendon strap is one of the non-pharmacologic interventions to alleviate knee pain. To investigate the immediate effect of a patellar tendon strap on weight-bearing asymmetry during squatting in people with unilateral knee osteoarthritis. Cross-sectional study. Ten patients with unilateral knee osteoarthritis and 10 healthy subjects were included in the study. Weight-bearing asymmetry of patients was assessed using a weight-bearing squat test during squatting at 30° and 60° both with and without patellar tendon strap. Pain intensity was assessed during squatting in unstrapped and strapped conditions with Visual Analog Scale. The decrease in weight-bearing asymmetry values immediately after wearing patellar tendon strap during 30° (p = 0.006) and 60° (p = 0.011) of squatting tests was significantly higher in knee osteoarthritis patients than in healthy subjects. Reported pain intensity was similar in unstrapped and strapped conditions (p = 0.066). The results of this study showed improved inter-limb weight-bearing symmetry during squatting. Further research with larger sample sizes investigating the effect of patellar tendon strap on weight-bearing asymmetry during functional activities in people with knee osteoarthritis is warranted. Patellar tendon straps (easily fit and cheap unlike knee braces) had more improvements in inter-limb weight-bearing symmetry during squatting in people with knee osteoarthritis compared to healthy subjects. This study is a new insight for future studies to investigate clinical benefits of wearing patellar tendon straps in this population. © The International Society for Prosthetics and Orthotics 2015.

Mid-term Results of Total Knee Arthroplasty Using PFC Sigma RP-F.

PubMed

Kim, Jun-Young; Cheon, Sang-Ho; Kyung, Hee-Soo

2012-12-01

We compared the mid-term results after total knee arthroplasty (TKA) using PFC Sigma RP-F mobile model with PFC Sigma PS fixed model. We analyzed 45 knees that underwent TKA with PFC Sigma RP-Fn (study group) and 45 knees with PFC Sigma PS (control group). The mean follow-up period was 65 months (range, 60-69 months). The evaluation system of the American knee society was used for clinical and radiological assessment. Also, the maximal knee flexion angle was assessed. The mean maximum flexion angle in the study group (135°) was greater than that in the control group (125°) at the early post-operation & final follow-up period (p=0.033). The range of motion (ROM) in the study group was recovered earlier at the postoperative 6 months, and ROM gain was improved to a greater extent at the final follow-up period (p=0.039). The knee score and function score and radiographic evaluation were no difference between the two groups (p>0.05) at the final follow-up. The two cases of radiolucency in posterior condyle and medial tibial plateau and one case of patellar elongation were seen in the study group. The PFC Sigma RP-F mobile system appears to facilitate greater maximum flexion angle and ROM gain with two cases of radiolucent line.

Design comparison: manipulation after total knee arthroplasty.

PubMed

Rogers, Jason M; Patel, Kevin V; Barnes, C Lowry

2015-01-01

Postoperative stiffness is a relatively uncommon issue in total knee arthroplasty (TKA). However, it can be a debilitating complication when it occurs. Manipulation under anesthesia (MUA) is commonly used as the primary treatment modality following failed physiotherapy. The Advance medial pivot knee (Wright Medical Technology) was created in an effort to prevent stiffness postoperatively and increase range of motion. The Evolution medial pivot knee is a second-generation design that builds on the technology of the Advance knee. This article presents a retrospective review of prospectively collected data on 881 primary medial pivot knees (592 Advance knees, 289 Evolution knees). It was theorized that the design changes made to the Evolution knees might contribute toward reducing the need for MUA. It was found that the Evolution knees required significantly fewer manipulations under anesthesia (p = .036). The design modifications made to the Evolution knees may have contributed to the lower rate of MUA.

Wear simulation of total knee prostheses using load and kinematics waveforms from stair climbing.

PubMed

Abdel-Jaber, Sami; Belvedere, Claudio; Leardini, Alberto; Affatato, Saverio

2015-11-05

Knee wear simulators are meant to perform load cycles on knee implants under physiological conditions, matching exactly, if possible, those experienced at the replaced joint during daily living activities. Unfortunately, only conditions of low demanding level walking, specified in ISO-14243, are used conventionally during such tests. A recent study has provided a consistent knee kinematic and load data-set measured during stair climbing in patients implanted with a specific modern total knee prosthesis design. In the present study, wear simulation tests were performed for the first time using this data-set on the same prosthesis design. It was hypothesised that more demanding tasks would result in wear rates that differ from those observed in retrievals. Four prostheses for total knee arthroplasty were tested using a displacement-controlled knee wear simulator for two million cycles at 1.1 Hz, under kinematics and load conditions typical of stair climbing. After simulation, the corresponding damage scars on the bearings were qualified and compared with equivalent explanted prostheses. An average mass loss of 20.2±1.5 mg was found. Scanning digital microscopy revealed similar features, though the explant had a greater variety of damage modes, including a high prevalence of adhesive wear damage and burnishing in the overall articulating surface. This study confirmed that the results from wear simulation machines are strongly affected by kinematics and loads applied during simulations. Based on the present results for the full understanding of the current clinical failure of knee implants, a more comprehensive series of conditions are necessary for equivalent simulations in vitro. Copyright © 2015 Elsevier Ltd. All rights reserved.

Anterior knee pain after a total knee arthroplasty: What can cause this pain?

PubMed Central

Breugem, Stéfanus Jacob Martinus; Haverkamp, Daniël

2014-01-01

Total Knee Arthroplasty has been shown to be a successful procedure for treating patients with osteoarthritis, and yet approximately 5%-10% of patients experience residual pain, especially in the anterior part of the knee. Many theories have been proposed to explain the etiology of this anterior knee pain (AKP) but, despite improvements having been made, AKP remains a problem. AKP can be described as retropatellar or peripatellar pain, which limits patients in their everyday lives. Patients suffering from AKP experience difficulty in standing up from a chair, walking up and down stairs and riding a bicycle. The question asked was: “How can a ‘perfectly’ placed total knee arthroplasty (TKA) still be painful: what can cause this pain?”. To prevent AKP after TKA it is important to first identify the different anatomical structures that can cause this pain. Greater attention to and understanding of AKP should lead to significant pain relief and greater overall patient satisfaction after TKA. This article is a review of what pain is, how nerve signalling works and what is thought to cause Anterior Knee Pain after a Total Knee Arthroplasty. PMID:25035818

Self-Reported Knee Instability Before and After Total Knee Replacement Surgery.

PubMed

Fleeton, Genevieve; Harmer, Alison R; Nairn, Lillias; Crosbie, Jack; March, Lyn; Crawford, Ross; van der Esch, Martin; Fransen, Marlene

2016-04-01

To determine the prevalence and burden of pain and activity limitations associated with retaining presurgery self-reported knee instability 6 months after total knee replacement (TKR) surgery and to identify early potentially modifiable risk factors for retaining knee instability in the operated knee after TKR surgery. A secondary analysis was performed using measures obtained from 390 participants undergoing primary unilateral TKR and participating in a randomized clinical trial. Self-reported knee instability was measured using 2 items from the Activities of Daily Living Scale of the Knee Outcome Survey. Outcome measures were knee pain (range 0-20) and physical function (range 0-68) on the Western Ontario and McMaster Universities Arthritis Index (WOMAC), stair-climb power, 50-foot walk time, knee range of motion, and isometric knee flexion and extension strength. In this study, 72% of participants reported knee instability just prior to surgery, with 32% retaining instability in the operated knee 6 months after surgery. Participants retaining operated knee instability had significantly more knee pain and activity limitations 6 months after surgery, with mean ± SD WOMAC scores of 4.8 ± 3.7 and 17.5 ± 11.1, respectively, compared to participants without knee instability, with 2.9 ± 3.1 and 9.8 ± 9.2. The multivariable predictor model for retained knee instability included a high comorbidity score (>6), low stair-climb power (<150 watts), more pain in the operated knee (>7 of 20), and younger age (<60 years). Self-reported knee instability is highly prevalent before and after TKR surgery and is associated with a considerable burden of pain and activity limitation in the operated knee. Increasing lower extremity muscle power may reduce the risk of retaining knee instability after TKR surgery. © 2016, American College of Rheumatology.

Posterior Cruciate Ligament Retention versus Posterior Stabilization for Total Knee Arthroplasty: A Meta-Analysis.

PubMed

Jiang, Chao; Liu, Zhenlei; Wang, Ying; Bian, Yanyan; Feng, Bin; Weng, Xisheng

2016-01-01

Although being debated for many years, the superiority of posterior cruciate-retaining (CR) total knee arthroplasty (TKA) and posterior-stabilized (PS) TKA remains controversial. We compare the knee scores, post-operative knee range of motion (ROM), radiological outcomes about knee kinematic and complications between CR TKA and PS TKA. Literature published up to August 2015 was searched in PubMed, Embase and Cochrane databases, and meta-analysis was performed using the software, Review Manager version 5.3. Totally 14 random control trials (RCTs) on this topic were included for the analysis, which showed that PS and CR TKA had no significant difference in Knee Society knee Score (KSS), pain score (KSPS), Hospital for Special Surgery score (HSS), kinematic characteristics including postoperative component alignment, tibial posterior slope and joint line, and complication rate. However, PS TKA is superior to CR TKA regarding post-operative knee range of motion (ROM) [Random Effect model (RE), Mean Difference (MD) = -7.07, 95% Confidential Interval (CI) -10.50 to -3.65, p<0.0001], improvement of ROM (Fixed Effect model (FE), MD = -5.66, 95% CI -10.79 to -0.53, p = 0.03) and femoral-tibial angle [FE, MD = 0.85, 95% CI 0.46 to 1.25, p<0.0001]. There are no clinically relevant differences between CR and PS TKA in terms of clinical, functional, radiological outcome, and complications, while PS TKA is superior to CR TKA in respects of ROM, while whether this superiority matters or not in clinical practice still needs further investigation and longer follow-up.

Customized versus Patient-Sized Cruciate-Retaining Total Knee Arthroplasty: An In Vivo Kinematics Study Using Mobile Fluoroscopy.

PubMed

Zeller, Ian M; Sharma, Adrija; Kurtz, William B; Anderle, Mathew R; Komistek, Richard D

2017-04-01

Historically, knee arthroplasties have been designed using average patient anatomy. Recent advances in imaging and manufacturing have facilitated the development of customized prostheses designed to fit the unique shape of individual patients. The purpose of this study is to determine if improving implant design through customized total knee arthroplasty (TKA) improves kinematic function. Using state-of-the-art mobile fluoroscopy, tibiofemoral kinematics were analyzed for 24 subjects with a customized individually made (CIM), cruciate-retaining TKA, and 14 subjects having an asymmetric condylar cruciate-retaining TKA. Subjects performed a weight-bearing deep knee bend and a rise from a seated position. Each patient was evaluated for weight-bearing range of motion, femorotibial translation, femorotibial axial rotation, and condylar liftoff occurrence. Subjects having a CIM TKA experienced greater weight-bearing knee flexion compared with the traditional posterior cruciate-retaining (PCR) TKA design. During flexion, the CIM TKA subjects consistently exhibited more posterior femoral rollback than the traditional PCR TKA subjects. The CIM TKA was found to have statistically greater axial rotation compared with the traditional PCR TKA (P = .05). Of note, only the CIM TKA patients experienced femoral internal rotation at full extension, as exhibited in a normal knee. Compared with the traditional PCR TKA, the CIM TKAs demonstrated minimal occurrences of paradoxical sliding and reverse rotation during flexion and extension. The CIM TKA subjects showed minimal liftoff and hence better stability in earlyflexion to midflexion compared with the traditional PCR subjects. The CIM TKA demonstrated kinematics more similar to a normal knee. Therefore, using customized implant technology through CIM TKA designs affords benefits including more normal motion compared with a traditional PCR TKA. Copyright © 2016 Elsevier Inc. All rights reserved.

Does the grading of chondromalacia patellae influence anterior knee pain following total knee arthroplasty without patellar resurfacing?

PubMed

Zha, Guo-Chun; Feng, Shuo; Chen, Xiang-Yang; Guo, Kai-Jin

2018-03-01

The influence of chondromalacia patellae (CMP) on post-operative anterior knee pain (AKP) following total knee arthroplasty (TKA) remains controversial, and few studies have focused on the relationship between them. The purpose of this study was to determine whether different CMP grades affect the incidence of AKP after TKA without patellar resurfacing. We performed a retrospective analysis of prospectively collected data on 290 TKAs with the use of the low contact stress mobile-bearing prosthesis, without patellar resurfacing in 290 patients from February 2009 to January 2013. Patients were assessed by the Outerbridge classification for CMP, visual analog scale for AKP, the Knee Society clinical scoring system of knee score (KS), function score (FS), the patellar score (PS) for clinical function, and patients' satisfaction. The intra-operative grading of CMP: grade I in 30 patients, grade II in 68 patients, grade III in 97 patients, and grade IV in 95 patients. The incidence of AKP at 36-month follow-up was 10.3% (30/290). No statistical difference was detected among the different CMP grades in terms of the incidence of AKP (p = 0.995), patients' satisfaction (p = 0.832), KS (p = 0.228), FS (p = 0.713), and PS (p = 0.119) at 36-month follow-up. The findings may suggest no relevant influence of CMP grading on the incidence of AKP after TKA without patellar resurfacing.

Altered knee and ankle kinematics during squatting in those with limited weight-bearing-lunge ankle-dorsiflexion range of motion.

PubMed

Dill, Karli E; Begalle, Rebecca L; Frank, Barnett S; Zinder, Steven M; Padua, Darin A

2014-01-01

Ankle-dorsiflexion (DF) range of motion (ROM) may influence movement variables that are known to affect anterior cruciate ligament loading, such as knee valgus and knee flexion. To our knowledge, researchers have not studied individuals with limited or normal ankle DF-ROM to investigate the relationship between those factors and the lower extremity movement patterns associated with anterior cruciate ligament injury. To determine, using 2 different measurement techniques, whether knee- and ankle-joint kinematics differ between participants with limited and normal ankle DF-ROM. Cross-sectional study. Sports medicine research laboratory. Forty physically active adults (20 with limited ankle DF-ROM, 20 with normal ankle DF-ROM). Ankle DF-ROM was assessed using 2 techniques: (1) nonweight-bearing ankle DF-ROM with the knee straight, and (2) weight-bearing lunge (WBL). Knee flexion, knee valgus-varus, knee internal-external rotation, and ankle DF displacements were assessed during the overhead-squat, single-legged squat, and jump-landing tasks. Separate 1-way analyses of variance were performed to determine whether differences in knee- and ankle-joint kinematics existed between the normal and limited groups for each assessment. We observed no differences between the normal and limited groups when classifying groups based on nonweight-bearing passive-ankle DF-ROM. However, individuals with greater ankle DF-ROM during the WBL displayed greater knee-flexion and ankle-DF displacement and peak knee flexion during the overhead-squat and single-legged squat tasks. In addition, those individuals also demonstrated greater knee-varus displacement during the single-legged squat. Greater ankle DF-ROM assessed during the WBL was associated with greater knee-flexion and ankle-DF displacement during both squatting tasks as well as greater knee-varus displacement during the single-legged squat. Assessment of ankle DF-ROM using the WBL provided important insight into compensatory

[Clinical effect of total knee arthroplasty on patients with knee osteoarthritis combined with mild to moderate valgus knee deformity].

PubMed

Chen, Peng; Zeng, Min; Xie, Jie; Wang, Long; Su, Weiping; Hu, Yihe

2016-09-28

To investigate the clinical effect of total knee arthroplasty on patients with knee osteoarthritis combined with mild to moderate valgus knee deformity.
 A total of 15 patients received total knee arthroplasty for correcting mild (10°-15°) to moderate (15°-30°) valgus knee between January 2011 and February 2014 in Xiangya Hospital of Central South University. We adopted a stable prosthesis surgery through patellar medial approach, osteophytes cleaning, conventional osteotomy, a selective soft tissue release and balance technical correcting of knee valgus deformity. Then conventional anticoagulation and symptomatic rehabilitation was utilized. Preoperative and postoperative X-ray was conducted in patients with measuring femor-tibial angle (FTA) and inspecting the prosthesis position. FTA, visual analog scale (VAS) standard, and parallel knee scoring system (KSS) were used to evaluate the clinical effect.
 Fifteen patients were followed up for 14 to 36 (22.40±11.88) months. The hospitalization time was 7-13 (7.73±1.58) d; operative time was 58-110 (81.8±16.85) min, the dominant blood loss was 140-600 (337.30±143.65) mL. Two cases had knee extension hysteresis, and the knee activity recovered after exercise. Leg power lines were normal. Three postoperative cases suffered anterior knee pain. They were subjected to celecoxib analgesic treatment and the pain gradually eased after 3 months. One postoperative case showed incision discharge and swelling, which was healed after change of dressing. During follow-up, review of X-ray film does not show prosthesis loose, subsidence and other complications. The knee valgus angle (8.1±1.8)°, knee motion range (107.33±9.61)°, KSS knee score (74.7±14.5, 75.3±2.7) and pain score (2.5±0.9) were significantly better than the preoperative (P<0.05). The clinical and function KSS scores showed that the improvement rate was 80%. 
 Total knee arthroplasty is an effective way to treat patients with knee osteoarthritis

Radiologic changes of ankle joint after total knee arthroplasty.

PubMed

Lee, Jung Hee; Jeong, Bi O

2012-12-01

The authors noticed that ankle joint osteoarthritis was not uncommon when lower extremity malalignment, such as a knee varus deformity, was present as a result of severe osteoarthritis of the knee. The purpose of this study was to analyze radiologic changes of the ankle joint after total knee arthroplasty. This study included 142 cases in 110 patients who underwent total knee arthroplasty and were followed for at least 3 years. The varus knee group included 128 cases and the valgus knee group included 14 cases. On anteroposterior standing lower extremity radiographs, varus and valgus angles of the knee were measured preoperatively and at the last follow-up. The angle between the ground surface and the distal tibial plafond as well as the upper talus was also measured. In addition, tibial anterior surface angle, talar tilt, space between the medial malleolar distal tip and the medial articular surface of the talus, and medial tibiotalar joint space of the ankle joint were measured. Out of 142 cases, 50 (35.2%) had arthritis in the ankle before total knee arthroplasty and 31 (21.8%) had newly developed or progressive arthritis after surgery. In particular, the varus knee group demonstrated statistically significant differences in preoperative varus deformity, preoperative talar tilt, and postoperative correction angle between the cases that developed or had progressive arthritis and those that did not show any changes (p < .05). After total knee arthroplasty, arthritis developed or progressed in the ankle of many cases radiographically. In particular, when the preoperative talar tilt increased medial to the ankle or the postoperative correction angle was large, the incidence of arthritis in the ankle joint increased. The authors recommend more cautious follow-up on the symptoms of the ankle joint after total knee arthroplasty.

Anteroposterior translation does not correlate with knee flexion after total knee arthroplasty.

PubMed

Ishii, Yoshinori; Noguchi, Hideo; Takeda, Mitsuhiro; Sato, Junko; Toyabe, Shin-ichi

2014-02-01

Stiffness after a TKA can cause patient dissatisfaction and diminished function, therefore it is important to characterize predictors of ROM after TKA. Studies of AP translation in conscious individuals disagree whether AP translation affects maximum knee flexion angle after implantation of a highly congruent sphere and trough geometry PCL-substituting prosthesis in a TKA. We investigated whether AP translation correlated with maximum knee flexion angle (1) in patients who were awake, and (2) who were under anesthesia (to minimize the effects of voluntary muscle contraction) in a TKA with implantation of a PCL-substituting mobile-bearing prosthesis. AP translation was examined under both conditions in 34 primary TKAs. Measurements under anesthesia were performed when the patients were having anesthesia for a contralateral TKA. Awake measurements were made within 4 days of that anesthetic session in patients who had no residual sedative effects. The average postoperative interval for the index TKA flexion measurements was 23 months (range, 6-114 months). AP translation was evaluated at 75° flexion using an arthrometer. There was no correlation between postoperative maximum knee flexion and AP translation at 75° during consciousness. There was no correlation between postoperative maximum knee flexion and AP translation under anesthesia. AP translation at 75° flexion did not correlate with postoperative maximum knee flexion in either awake or anesthetized patients during a TKA with implantation of a posterior cruciate-substituting prosthesis.

Comparison of robot surgery modular and total knee arthroplasty kinematics.

PubMed

Yildirim, Gokce; Fernandez-Madrid, Ivan; Schwarzkopf, Ran; Walker, Peter S; Karia, Raj

2014-04-01

The kinematics of seven knee specimens were measured from 0 to 120 degrees flexion using an up-and-down crouching machine. Motion was characterized by the positions of the centers of the lateral and medial femoral condyles in the anterior-posterior direction relative to a fixed tibia. A modular unicompartmental knee, trochlea flange, and patella resurfacing (multicompartmental knee [MCK] system) were implanted using a surgeon-interactive robot system that provided accurate surface matching. The MCK was tested, followed by standard cruciate retaining (CR) and posterior stabilized (PS) knees. The motion of the MCK was close to anatomic, especially on the medial side, in contrast to the CR and PS knees that showed abnormal motion features. Such a modular knee system, accurately inserted, has the potential for close to normal function in clinical application. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Knee arthrodesis using a customised modular intramedullary nail in failed infected total knee arthroplasty.

PubMed

Putman, S; Kern, G; Senneville, E; Beltrand, E; Migaud, H

2013-06-01

Knee arthrodesis is used to treat patients with failed infected total knee arthroplasty (TKA). Among fixation methods, intramedullary nailing increases the chances of bone union but may carry a risk of infection around the nail. This risk is not well understood, because available case-series studies were not confined to patients with knee infection. Infection recurrence rates after knee arthrodesis with intramedullary nailing used to treat failed infected TKA are similar to those seen with other fixation methods. We retrospectively reviewed 31 cases of knee arthrodesis with fixation by a modular intramedullary nail performed at a subspecialized center treating complex osteoarticular infections (CRIOAC). The antibiotic regimen was determined based on multidisciplinary discussions and microbiological studies of preoperative and intraoperative specimens. Mean follow-up was 50 ± 22 months (range, 28-90 months). Arthrodesis was performed in one stage (n=6) or two stages (n=25). Success was defined as presence, after a postoperative follow-up of at least 24 months, based on the following criteria: normal erythrocyte sedimentation rate and/or C-reactive protein, no wound inflammation or sinus tract, no revision surgery, and no antibiotic treatment. Bone union was not a criterion for a successful arthrodesis procedure. Removal of the fixation material was required in three patients and long-term palliative antibiotic therapy in three patients (fixation material in place with repeated positive specimens) for a total of six failures due to infection (6/31, 19.4%). None of the patients experienced mechanical failure (no breakage of the material and no fixation failure of the nails designed to allow osteointegration). The mean leg length discrepancy was 10 ± 10 mm (range, 5-34 mm) and the mean Oxford score was 41 ± 11 (range, 23-58). The 50-month rate of arthrodesis survival to revision surgery for nail removal was 77.8 ± 4% and the 50-month rate of arthrodesis survival

Arthrodesis with a short Huckstep nail as a salvage procedure for failed total knee arthroplasty.

PubMed

Lai, K A; Shen, W J; Yang, C Y

1998-03-01

Arthrodesis of the knee with use of a short Huckstep nail was performed in thirty-three patients (thirty-three knees) after failure of a non-constrained total knee arthroplasty. The indication for the arthrodesis was an infection in thirty-one knees and a Charcot joint in two. Three knees had had a failed attempt at arthrodesis with use of external fixation. The Huckstep nail was inserted through the knee, retrograde into the femur, and then antegrade into the tibia. The duration of the operation averaged 104 minutes (range, sixty-five to 155 minutes). Local bone graft was used in all knees. At the time of follow-up, at an average of forty-seven months (range, eighteen to ninety-four months), thirty knees (91 per cent) had radiographic evidence of union. The average time to union was 5.2 months (range, two to ten months) after the arthrodesis. Eight knees that had a grossly purulent infection were treated with debridement, which was followed by the arthrodesis as a second-stage procedure; the other knees had a one-stage arthrodesis. Only one of the thirty-one knees that had had an infection before the arthrodesis had a recurrence after it. Arthrodesis with a short Huckstep nail provides immediate axial and rotational stability and allows weight-bearing without use of external support as well as placement of the knee in a slightly flexed and valgus position. In addition, the nail does not migrate and it may be used even when there is a standard-size prosthesis in the ipsilateral hip.

The effects of dimensional parameters on sensing and energy harvesting of an embedded PZT in a total knee replacement

NASA Astrophysics Data System (ADS)

Safaei, Mohsen; Anton, Steven R.

2016-04-01

Total Knee Replacement (TKR), one of the most common surgeries in the United States, is performed when the patient is experiencing significant amounts of pain or when knee functionality has become substantially degraded. Despite impressive recent developments, only about 85% of patients are satisfied with the pain reduction after one year. Therefore, structural health and performance monitoring are integral for intraoperative and postoperative feedback. In extension of the author's previous work, a new configuration for implementation of piezoelectric transducers in total knee replacement bearings is proposed and FEA modeling is performed to attain appropriate sensing and energy harvesting ability. The predicted force transmission ratio to the PZT (ratio of force applied to the bearing to force transferred to the embedded piezoelectric transducer) is about 6.2% compared to about 5% found for the previous encapsulated design. Dimensional parameters of the polyethylene bearing including the diameter and depth of the PZT pocket as well as the placement geometry of the PZT transducer within the bearing are hypothesized as the most influential parameters on the performance of the designed system. The results show a small change of 1% and 2.3% in the output of the system as a result of variation in the PZT location and pocket diameter, respectively. Whereas, the output of the system is significantly sensitive to the pocket depth; a pocket 0.01 mm deeper than the PZT transducer leads to no force transmission, and a pocket 0.15 mm shallower leads to full load transmission to the PZT. In order to develop a self-powered sensor, the amount of energy harvested from tibial forces for the proposed geometry is investigated.

In vivo determination of total knee arthroplasty kinematics

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

Komistek, Richard D; Mahfouz, Mohamed R; Bertin, Kim

2008-01-01

The objective of this study was to determine if consistent posterior femoral rollback of an asymmetrical posterior cruciate retaining (PCR) total knee arthroplasty was mostly influenced by the implant design, surgical technique, or presence of a well-functioning posterior cruciate ligament (PCL). Three-dimensional femorotibial kinematics was determined for 80 subjects implanted by 3 surgeons, and each subject was evaluated under fluoroscopic surveillance during a deep knee bend. All subjects in this present study having an intact PCL had a well-functioning PCR knee and experienced normal kinematic patterns, although less in magnitude than the normal knee. In addition, a surprising finding wasmore » that, on average, subjects without a PCL still achieved posterior femoral rollback from full extension to maximum knee flexion. The findings in this study revealed that implant design did contribute to the normal kinematics demonstrated by subjects having this asymmetrical PCR total knee arthroplasty.« less

Mobile-bearing medial unicompartmental knee arthroplasty restores limb alignment comparable to that of the unaffected contralateral limb

PubMed Central

Mullaji, Arun B; Shah, Siddharth; Shetty, Gautam M

2017-01-01

Background and purpose — Medial unicompartmental knee arthroplasty (UKA) is undertaken in patients with a passively correctable varus deformity. We investigated whether restoration of natural soft tissue tension would result in a lower limb alignment similar to that of the contralateral unaffected lower limb after mobile-bearing medial UKA. Patients and methods — In this retrospective study, hip-knee-ankle (HKA) angle, position of the weight-bearing axis (WBA), and knee joint line obliquity (KJLO) after mobile-bearing medial UKA was compared with that of the unaffected (clinically and radiologically) contralateral lower limb in 123 patients. Results — Postoperatively, HKA angle was restored to within ±3° of the contralateral lower limb in 87% of the patients and the WBA passed within ±1 Kennedy and White’s tibial zone of the unaffected contralateral lower limb in 95% of the patients. The mean KJLO in the operated limbs was not significantly different from that in the unaffected lower limbs (p = 0.07) and the KJLO in the operated limb was restored to within ±3° of that in the contralateral lower limb in 96% of the patients. Interpretation — Lower limb alignment and knee joint line obliquity after mobile-bearing medial UKA were comparable to that of the unaffected contralateral limb in most patients. Comparison with the contralateral unaffected lower limb is a reliable method for evaluation and validation of limb mechanical alignment after mobile-bearing medial UKA. PMID:27794622

Radiographic assessment of knee-ankle alignment after total knee arthroplasty for varus and valgus knee osteoarthritis.

PubMed

Gao, Fuqiang; Ma, Jinhui; Sun, Wei; Guo, Wanshou; Li, Zirong; Wang, Weiguo

2017-01-01

There are unanswered questions about knee-ankle alignment after total knee arthroplasty (TKA) for varus and valgus osteoarthritis (OA) of the knee. The aim of this retrospective study was to assess knee-ankle alignment after TKA. The study consisted of 149 patients who had undergone TKA due to varus and valgus knee OA. The alignment and angles in the selected knees and ankles were measured on full-length standing anteroposterior radiographs, both pre-operatively and post-operatively. The paired t-test and Pearson's correlation tests were used for statistical analysis. The results showed that ankle alignment correlated with knee alignment both pre-operatively and postoperatively (P<0.05). The pre-operative malalignment of the knee was corrected (P<0.05), and the ankle tilt angle was accordingly improved in the operative side after TKA (P<0.05). In addition, TKA had little effect on knee-ankle alignment on the non-operative side (P>0.05). These findings indicated that routine TKA could correct the varus or valgus deformity of a knee, and improve the tilt of the ankle. Ankle alignment correlated with knee alignment both pre-operatively and postoperatively. Both pre-operative knee and ankle malalignment can be simultaneously corrected following TKA. Level III. Copyright © 2016 Elsevier B.V. All rights reserved.

Total knee replacement with natural rollback.

PubMed

Wachowski, Martin Michael; Walde, Tim Alexander; Balcarek, Peter; Schüttrumpf, Jan Philipp; Frosch, Stephan; Stauffenberg, Caspar; Frosch, Karl-Heinz; Fiedler, Christoph; Fanghänel, Jochen; Kubein-Meesenburg, Dietmar; Nägerl, Hans

2012-03-20

A novel class of total knee replacement (AEQUOS G1) is introduced which features a unique design of the articular surfaces. Based on the anatomy of the human knee and differing from all other prostheses, the lateral tibial "plateau" is convexly curved and the lateral femoral condyle is posteriorly shifted in relation to the medial femoral condyle. Under compressive forces the configuration of the articular surfaces of human knees constrains the relative motion of femur and tibia in flexion/extension. This constrained motion is equivalent to that of a four-bar linkage, the virtual 4 pivots of which are given by the centres of curvature of the articulating surfaces. The dimensions of the four-bar linkage were optimized to the effect that constrained motion of the total knee replacement (TKR) follows the flexional motion of the human knee in close approximation, particularly during gait. In pilot studies lateral X-ray pictures have demonstrated that AEQUOS G1 can feature the natural rollback in vivo. Rollback relieves the load of the patello-femoral joint and minimizes retropatellar pressure. This mechanism should reduce the prevalence of anterior knee pain. The articulating surfaces roll predominantly in the stance phase. Consequently sliding friction is replaced by the lesser rolling friction under load. Producing rollback should minimize material wear due to friction and maximize the lifetime of the prosthesis. To definitely confirm these theses one has to wait for the long term results. Copyright © 2011 Elsevier GmbH. All rights reserved.

Knee arthrodesis as limb salvage for complex failures of total knee arthroplasty.

PubMed

Kuchinad, Raul; Fourman, Mitchell S; Fragomen, Austin T; Rozbruch, S Robert

2014-11-01

Patients with multiple failures of total knee arthroplasty (TKA) are challenging limb salvage cases. Twenty one patients over the last 10 years were referred to our service for knee fusion by arthroplasty surgeons who felt they were not candidates for revision TKA. Active infection was present in 76.2% and total bone loss averaged 6.6 cm. Lengthening was performed in 7/22 patients. Total time in Ilizarov frames was 9 months, with 93.3% union. Patients treated with IM fusion nails had 100% union. Average LLD increased from 3.6 to 4.5 cm following intervention, while those with concurrent lengthening improved to 1.6 cm. Findings suggest that bone loss and the soft-tissue envelope dictate knee fusion method, and multiple techniques may be needed. A treatment algorithm is presented. Copyright © 2014 Elsevier Inc. All rights reserved.

Salvage of infected total knee fusion: the last option.

PubMed

Wiedel, Jerome D

2002-11-01

Currently the most common indication for an arthrodesis of the knee is a failed infected total knee prosthesis. Other causes of a failed total knee replacement that might necessitate a knee fusion include aseptic loosening, deficient extensor mechanism, poor soft tissues, and Charcot joint. Techniques available for achieving a knee fusion are external fixation and internal fixation methods. The external fixation compression devices have been the most widely used for knee fusion and have been successful until the indications for fusion changed to mostly failed prosthetic knee replacement. With failed total knee replacement, the problem of severe bone loss became an issue, and the external fixation compression devices, even including the biplane external fixators, have been the least successful method reported for gaining fusion. The Ilizarov technique has been shown to achieve rigid fixation despite this bone loss, and a review of reports are showing high fusion rates using this method. Internal fixation methods including plate fixation and intramedullary nails have had the best success in gaining fusion in the face of this bone loss and have replaced external fixation methods as the technique of choice for knee fusion when severe bone loss is present. A review of the literature and a discussion of different fusion techniques are presented including a discussion of the influence that infection has on the success of fusion.

The importance of bony impingement in restricting flexion after total knee arthroplasty: computer simulation model with clinical correlation.

PubMed

Mizu-Uchi, Hideki; Colwell, Clifford W; Fukagawa, Shingo; Matsuda, Shuichi; Iwamoto, Yukihide; D'Lima, Darryl D

2012-10-01

We constructed patient-specific models from computed tomography data after total knee arthroplasty to predict knee flexion based on implant-bone impingement. The maximum flexion before impingement between the femur and the tibial insert was computed using a musculoskeletal modeling program (KneeSIM; LifeModeler, Inc, San Clemente, California) during a weight-bearing deep knee bend. Postoperative flexion was measured in a clinical cohort of 21 knees (low-flex group: 6 knees with <100° of flexion and high-flex group: 15 size-matched knees with >125° of flexion at 2 years). Average predicted flexion angles were within 2° of clinical measurements for the high-flex group. In the low-flex group, 4 cases had impingement involving the bone cut at the posterior condyle, and the average predicted knee flexion was 102° compared with 93° measured clinically. These results indicate that the level of the distal femoral resection should be carefully planned and that exposed bone proximal to the tips of the posterior condyles of the femoral component should be removed if there is risk of impingement. Copyright © 2012 Elsevier Inc. All rights reserved.

Outcomes of Total Knee Arthroplasty in Patients With Poliomyelitis.

PubMed

Gan, Zhi-Wei Jonathan; Pang, Hee Nee

2016-11-01

We report our experience with outcomes of poliomyelitis in the Asian population. Sixteen total knee replacements in 14 patients with polio-affected knees were followed up for at least 18 months. Follow-up assessment included scoring with the American Knee Society Score (AKSS), Oxford knee score, and Short Form 36 Health Survey scores. The mean AKSS improved from 25.59 preoperatively to 82.94 at 24 months, with greater improvement in the knee score. The mean Oxford knee score improved from 40.82 preoperatively to 20.53 at 24 months. The mean AKSS pain score rose from 2.35 to 47.66 at 24 months. The Short Form 36 Health Survey physical functioning and bodily pain scores improved for all patients. Primary total knee arthroplasty of poliomyelitis-affected limbs shows good outcomes, improving quality of life, and decreasing pain. Copyright © 2016 Elsevier Inc. All rights reserved.

Looks good but feels bad: factors that contribute to poor results after total knee arthroplasty.

PubMed

Fisher, David A; Dierckman, Brian; Watts, Melanie R; Davis, Kenneth

2007-09-01

The purpose of this study was to evaluate patient factors that might contribute to a poor result after total knee arthroplasty (TKA). Seventy-one knees (6.9%) of 1024 primary TKAs were identified at 1 year follow-up as having a poor result because of either stiffness or pain. Radiographs demonstrated well-fixed and aligned implants. This group was compared with a matched control group of 148 nonpainful or stiff TKAs, with similar range of motion preoperatively. Logistic regression analysis was performed to compare age, sex, body mass index, comorbidities, previous surgeries, preoperative narcotic use, tobacco or alcohol use, work status, insurance status, and any history of depression. Factors that were significantly associated with a stiff or painful outcome included female sex, higher body mass index, previous knee surgery, patients on disability, diabetes mellitus, pulmonary disease, and depression.

Design of various fixed-geometry water-lubricated hydrodynamic journal bearings for maximum stability

NASA Technical Reports Server (NTRS)

Schuller, F. T.

1973-01-01

This publication is the result of over 260 fractional-frequency-whirl stability tests on a variety of fixed-geometry journal bearings. It is intended principally as a guide in the selection and design of antiwhirl bearings that must operate at high speeds and low loads in low-viscosity fluids such as water or liquid metals. However, the various fixed-geometry configurations can be employed as well in applications where other lubricants, such as oil, are used and fractional-frequency whirl is a problem. The important parameters that effect stability are discussed for each bearing type, and design curves to facilitate the design of optimum-geometry bearings are included. A comparison of the stability of the different bearing configurations tested is also given.

Biomechanical Effects of Posterior Condylar Offset and Posterior Tibial Slope on Quadriceps Force and Joint Contact Forces in Posterior-Stabilized Total Knee Arthroplasty.

PubMed

Kang, Kyoung-Tak; Koh, Yong-Gon; Son, Juhyun; Kwon, Oh-Ryong; Lee, Jun-Sang; Kwon, Sae Kwang

2017-01-01

This study aimed to determine the biomechanical effect of the posterior condylar offset (PCO) and posterior tibial slope (PTS) in posterior-stabilized (PS) fixed-bearing total knee arthroplasty (TKA). We developed ±1, ±2, and ±3 mm PCO models in the posterior direction and -3°, 0°, 3°, and 6° PTS models using a previously validated FE model. The influence of changes in the PCO and PTS on the biomechanical effects under deep-knee-bend loading was investigated. The contact stress on the PE insert increased by 14% and decreased by 7% on average as the PCO increased and decreased, respectively, compared to the neutral position. In addition, the contact stress on post in PE insert increased by 18% on average as PTS increased from -3° to 6°. However, the contact stress on the patellar button decreased by 11% on average as PTS increased from -3° to 6° in all different PCO cases. The quadriceps force decreased by 14% as PTS increased from -3° to 6° in all PCO models. The same trend was found in patellar tendon force. Changes in PCO had adverse biomechanical effects whereas PTS increase had positive biomechanical effects. However, excessive PTS should be avoided to prevent knee instability and subsequent failure.

The Effect on Long-Term Survivorship of Surgeon Preference for Posterior-Stabilized or Minimally Stabilized Total Knee Replacement: An Analysis of 63,416 Prostheses from the Australian Orthopaedic Association National Joint Replacement Registry.

PubMed

Vertullo, Christopher J; Lewis, Peter L; Lorimer, Michelle; Graves, Stephen E

2017-07-05

Controversy still exists as to the optimum management of the posterior cruciate ligament (PCL) in total knee arthroplasty. Surgeons can choose to kinematically substitute the PCL with a posterior-stabilized total knee replacement or alternatively to utilize a cruciate-retaining, also known as minimally stabilized, total knee replacement. Proponents of posterior-stabilized total knee replacement propose that the reported lower survivorship in registries when directly compared with minimally stabilized total knee replacement is due to confounders such as selection bias because of the preferential usage of posterior-stabilized total knee replacement in more complex or severe cases. In this study, we aimed to eliminate these possible confounders by performing an instrumental variable analysis based on surgeon preference to choose either posterior-stabilized or minimally stabilized total knee replacement, rather than the actual prosthesis received. Cumulative percent revision, hazard ratio (HR), and revision diagnosis data were obtained from the Australian Orthopaedic Association National Joint Replacement Registry from September 1, 1999, to December 31, 2014, for 2 cohorts of patients, those treated by high-volume surgeons who preferred minimally stabilized replacements and those treated by high-volume surgeons who preferred posterior-stabilized replacements. All patients had a diagnosis of osteoarthritis and underwent fixed-bearing total knee replacement with patellar resurfacing. At 13 years, the cumulative percent revision was 5.0% (95% confidence interval [CI], 4.0% to 6.2%) for the surgeons who preferred the minimally stabilized replacements compared with 6.0% (95% CI, 4.2% to 8.5%) for the surgeons who preferred the posterior-stabilized replacements. The revision risk for the surgeons who preferred posterior-stabilized replacements was significantly higher for all causes (HR = 1.45 [95% CI, 1.30 to 1.63]; p < 0.001), for loosening or lysis (HR = 1.93 [95% CI, 1

Joint Line Reconstruction in Navigated Total Knee Arthroplasty Revision

ClinicalTrials.gov

2012-05-16

Revision Total Knee Arthroplasty Because of; Loosening; Instability; Impingement; or Other Reasons Accepted as Indications for TKA Exchange.; The Focus is to Determine the Precision of Joint Line Restoration in Navigated vs. Conventional Revision Total Knee Arthroplasty

[PERSONALIZED DISTAL FEMORAL VALGUS RESECTION ANGLE IN PRIMARY TOTAL KNEE ARTHROPLASTY].

PubMed

Wang, Xilong; Shang, Xifu; Ll, Guoyuan; He, Rui; Zheng, Jie

2015-01-01

To investigate the feasibility and effectiveness of a personalized distal femoral valgus resection angle for improving postoperative coronal alignment of lower limb in total knee arthroplasty (TKA). A retrospective analysis was made on the clinical data of 50 patients who received primary TKA between January 2013 and February 2013. There were 11 male and 39 female patients with degenerative knee osteoarthritis. The patients were divided into 2 groups. In test group (n=25), the resection angle was adjusted to the femoral mechanical anatomical angle (FMA); in control group (n=25), a fixed distal valgus resection angle of 5° was used. There was no significant difference in gender, age, body mass index, disease duration, sides, grade, preoperative FMA, mechanical femorotibial angle (MFT), and preoperative Knee Society Score (KSS) between 2 groups (P > 0.05). Whole long X-ray film was taken to measure FMA and MFT at 3 days after operation, postoperative KSS was used to evaluate the knee function after 6 and 15 months. MFT was (-0.20 ± 1.87)° in test group and was (1.71 ± 3.67)° in control group, showing significant difference between 2 groups (t = 2.32, P = 0.02). The ideal MFT angle (0 ± 3)° was achieved in 22 patients (88%) of test group and in 16 patients (64%) of control group, showing significant difference between 2 groups (χ2 = 2.32, P = 0.02). Primary healing of incision was obtained in all patients of 2 groups. No deep venous thrombosis occurred. The patients of 2 groups were followed up 15 months after operation. There was significant difference in KSS between test and control groups at 6 months (88.23 ± 2.57 vs. 82.92 ± 2.59) (t = 7.26, P = 0.00) and at 15 months (90.76 ± 2.77 vs. 88.65 ± 1.77) (t = 3.20, P = 0.02). No sign of prosthesis loosening was observed by X-ray examination. Compared with using of a fixed distal femoral resection angle, an individual FMA can significantly improve the postoperative MFT and promote early recovery of the knee

Elbow and knee joint for hard space suits

NASA Technical Reports Server (NTRS)

Vykukal, H. C.

1986-01-01

An elbow or knee joint for a hard space suit or similar usage is formed of three serially connected rigid sections which have truncated spherical configurations. The ends of each section form solid geometric angles, and the sections are interconnected by hermetically sealed ball bearings. The outer two sections are fixed together for rotation in a direction opposite to rotation of the center section. A preferred means to make the outer sections track each other in rotation comprises a rotatable continuous bead chain which engages sockets circumferentially spaced on the facing sides of the outer races of the bearings. The joint has a single pivot point and the bearing axes are always contained in a single plane for any articulation of the joint. Thus flexure of the joint simulates the coplanar flexure of the knee or elbow and is not susceptible to lockup.

Impact of Tranexamic Acid in Total Knee and Total Hip Replacement.

PubMed

Boyle, Jaclyn A; Soric, Mate M

2017-02-01

To evaluate the net clinical benefit of tranexamic acid use in patients undergoing total knee or total hip replacement. This is a retrospective study of patients undergoing total knee or total hip replacement. The primary outcome was the net clinical benefit of tranexamic acid use. Secondary outcomes included length of stay, incidence of venous thromboembolism, change in hemoglobin, and number of units of blood transfused. Four hundred and six patients were screened for inclusion and 327 patients met inclusion criteria; 174 patients received tranexamic acid versus 153 patients who received usual care. Tranexamic acid demonstrated a positive net clinical benefit versus usual care (40.8% vs 13.7%, P < .01) but did not affect length of stay (3.39 vs 3.37 days, respectively, P = .76). Venous thromboembolism was comparable between groups (2.3% vs 0.7%, P = .38). Average change in hemoglobin and need for transfusion were lower in the treatment group versus the usual care group, respectively (3.46 vs 4.26 mg/dL, P < .01). Tranexamic acid demonstrated a significant benefit in decreasing change in hemoglobin as well as the need for blood transfusion with no increase in the risk of venous thromboembolism in patients undergoing total knee or total hip replacement.

Is unicompartmental knee arthroplasty (UKA) superior to total knee arthroplasty (TKA)? A systematic review and meta-analysis of randomized controlled trial.

PubMed

Arirachakaran, Alisara; Choowit, Pathompong; Putananon, Chinundorn; Muangsiri, Samart; Kongtharvonskul, Jatupon

2015-07-01

To compare clinical outcomes of unicompartmental knee arthroplasty (UKA) versus total knee arthroplasty (TKA). A systematic review and meta-regression to compare postoperative outcomes of pain VAS, knee function score, range of motion, complications and revision surgery rates between UKA and TKA were conducted. Relevant randomized controlled trials were identified from MEDLINE and Scopus from inception to August 29, 2014. Three of 1056 studies were eligible; two, three, two, three and three studies were included in pooling of pain visual analog score (VAS), Knee Society Score (KSS) and Bristol Knee Score (BKS), maximum knee flexion, postoperative complications (aseptic loosening, progressive degenerative joint disease of lateral compartment, bearing dislocation, DVT, fractures and infection) and revision rates, respectively. The unstandardized mean difference (UMD) of the function scores (KSS, BS) for UKA was 1.62 (95 % CI -1.17, 4.42) better than TKA and for pain score was 0.1 (95 % CI -3.54, 3.73) higher than TKA, but both without statistical significance. UKA was more likely to show higher mean maximum knee flexion with a UMD of 1.88 (95 % CI -0.54, 4.30) when compared to TKA, but was also not statistically significant. UKA had a statistically significant lower chance of postoperative complications by 0.35 U (95 % CI 0.12, 0.98) when compared to TKA, but had higher revision rates than TKA with a value of 5.36 (95 % CI 1.06, 27.08). In short-term outcomes (5 years or less, with follow-up of 0-5 years), TKA had higher postoperative complications than UKA, but had lower revision rates. There was only one study that reported long-term survivorship (more than 5 years, with follow-up of 5-15 years). Further research that assesses long-term survivorship is necessary to better evaluate UKA and TKA in the treatment of unicompartmental knee osteoarthritis.

Prevalence of Total Hip and Knee Replacement in the United States.

PubMed

Maradit Kremers, Hilal; Larson, Dirk R; Crowson, Cynthia S; Kremers, Walter K; Washington, Raynard E; Steiner, Claudia A; Jiranek, William A; Berry, Daniel J

2015-09-02

Descriptive epidemiology of total joint replacement procedures is limited to annual procedure volumes (incidence). The prevalence of the growing number of individuals living with a total hip or total knee replacement is currently unknown. Our objective was to estimate the prevalence of total hip and total knee replacement in the United States. Prevalence was estimated using the counting method by combining historical incidence data from the National Hospital Discharge Survey and the Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases from 1969 to 2010 with general population census and mortality counts. We accounted for relative differences in mortality rates between those who have had total hip or knee replacement and the general population. The 2010 prevalence of total hip and total knee replacement in the total U.S. population was 0.83% and 1.52%, respectively. Prevalence was higher among women than among men and increased with age, reaching 5.26% for total hip replacement and 10.38% for total knee replacement at eighty years. These estimates corresponded to 2.5 million individuals (1.4 million women and 1.1 million men) with total hip replacement and 4.7 million individuals (3.0 million women and 1.7 million men) with total knee replacement in 2010. Secular trends indicated a substantial rise in prevalence over time and a shift to younger ages. Around 7 million Americans are living with a hip or knee replacement, and consequently, in most cases, are mobile, despite advanced arthritis. These numbers underscore the substantial public health impact of total hip and knee arthroplasties. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

Assessment of patient functional performance in different knee arthroplasty designs during unconstrained squat

PubMed Central

Verdini, Federica; Zara, Claudio; Leo, Tommaso; Mengarelli, Alessandro; Cardarelli, Stefano; Innocenti, Bernardo

2017-01-01

Summary Background In this paper, squat named by Authors unconstrained because performed without constrains related to feet position, speed, knee maximum angle to be reached, was tested as motor task revealing differences in functional performance after knee arthroplasty. It involves large joints ranges of motion, does not compromise joint safety and requires accurate control strategies to maintain balance. Methods Motion capture techniques were used to study squat on a healthy control group (CTR) and on three groups, each characterised by a specific knee arthroplasty design: a Total Knee Arthroplasty (TKA), a Mobile Bearing and a Fixed Bearing Unicompartmental Knee Arthroplasty (respectively MBUA and FBUA). Squat was analysed during descent, maintenance and ascent phase and described by speed, angular kinematics of lower and upper body, the Center of Pressure (CoP) trajectory and muscle activation timing of quadriceps and biceps femoris. Results Compared to CTR, for TKA and MBUA knee maximum flexion was lower, vertical speed during descent and ascent reduced and the duration of whole movement was longer. CoP mean distance was higher for all arthroplasty groups during descent as higher was, CoP mean velocity for MBUA and TKA during ascent and descent. Conclusions Unconstrained squat is able to reveal differences in the functional performance among control and arthroplasty groups and between different arthroplasty designs. Considering the similarity index calculated for the variables showing statistically significance, FBUA performance appears to be closest to that of the CTR group. Level of evidence III a. PMID:29387646

Current and innovative pain management techniques in total knee arthroplasty.

PubMed

Dalury, David F; Lieberman, Jay R; Macdonald, Steven J

2012-01-01

Pain management is a major concern for patients contemplating total knee replacement surgery and is one of the leading causes of dissatisfaction after knee replacement. Substantial progress has been made over the past several years in improving pain control after total knee replacement using multimodal pain control, preemptive analgesia, and periarticular injections.

The Cruciate Ligaments in Total Knee Arthroplasty.

PubMed

Parcells, Bertrand W; Tria, Alfred J

2016-01-01

The early knee replacements were hinge designs that ignored the ligaments of the knee and resurfaced the joint, allowing freedom of motion in a single plane. Advances in implant fixation paved the way for modern designs, including the posterior-stabilized (PS) total knee arthroplasty (TKA) that sacrifices both cruciate ligaments while substituting for the posterior cruciate ligament (PCL), and the cruciate-retaining (CR) TKA designs that sacrifice the anterior cruciate ligament but retain the PCL. The early bicruciate retaining (BCR) TKA designs suffered from loosening and early failures. Townley and Cartier designed BCR knees that had better clinical results but the surgical techniques were challenging.Kinematic studies suggest that normal motion relies on preservation of both cruciate ligaments. Unicompartmental knee arthroplasty retains all knee ligaments and closely matches normal motion, while PS and CR TKA deviate further from normal. The 15% to 20% dissatisfaction rate with current TKA has renewed interest in the BCR design. Replication of normal knee kinematics and proprioception may address some of the dissatisfaction.

Gender differences in tibio-femoral kinematics and quadriceps muscle force during weight-bearing knee flexion in vitro.

PubMed

Wünschel, Markus; Wülker, Nikolaus; Müller, Otto

2013-11-01

Females have a higher risk in terms of anterior cruciate ligament injuries during sports than males. Reasons for this fact may be different anatomy and muscle recruitment patterns leading to less protection for the cruciate- and collateral-ligaments. This in vitro study aims to evaluate gender differences in knee joint kinematics and muscle force during weight-bearing knee flexions. Thirty-four human knee specimens (17 females/17 males) were mounted on a dynamic knee simulator. Weight-bearing single-leg knee flexions were performed with different amounts of simulated body weight (BW). Gender-specific kinematics was measured with an ultrasonic motion capture system and different loading conditions were examined. Knee joint kinematics did not show significant differences regarding anteroposterior and medial-lateral movement as well as tibial varus-valgus and internal-external rotation. This applied to all simulated amounts of BW. Simulating 100 N BW in contrast to AF50 led to a significant higher quadriceps overall force in female knees from 45° to 85° of flexion in contrast to BW 50 N. In these female specimens, the quadriceps overall force was about 20 % higher than in male knees being constant in higher flexion angles. It is indicated by our results that in a squatting movement females compared with males produce higher muscle forces, suggesting an increased demand for muscular stabilization, whereas tibio-femoral kinematics was similar for both genders.

Knee arthrodesis in failed total knee arthroplasty with severe osteolysis and ipsilateral long-stem total hip arthroplasty.

PubMed

Sim, Jae Ang; Lee, Beom Koo; Kwak, Ji Hoon; Moon, Sung Hoon

2009-02-01

We report a case of knee fusion after a failed total knee arthroplasty (TKA) with severe osteolysis including the epicondyle and ipsilateral total hip arthroplasty (THA) with long Wagner revision stem (Sulzer Orthopedics, Baar, Switzerland). The conventional devices for arthrodesis were unavailable in this case because of the long Wagner revision stem and poor bone stock. A connector was made between the long Wagner revision stem and an intramedullary nail (IM nail; Solco, Seoul, Korea). The custom-made connector was coupled with a femoral stem by cylindrical taper fit with additional cement augmentation and an intramedullary nail by screws. Osseous fusion was achieved without pain or instability.

The robustness and accuracy of in vivo linear wear measurements for knee prostheses based on model-based RSA.

PubMed

van Ijsseldijk, E A; Valstar, E R; Stoel, B C; Nelissen, R G H H; Reiber, J H C; Kaptein, B L

2011-10-13

Accurate in vivo measurements methods of wear in total knee arthroplasty are required for a timely detection of excessive wear and to assess new implant designs. Component separation measurements based on model-based Roentgen stereophotogrammetric analysis (RSA), in which 3-dimensional reconstruction methods are used, have shown promising results, yet the robustness of these measurements is unknown. In this study, the accuracy and robustness of this measurement for clinical usage was assessed. The validation experiments were conducted in an RSA setup with a phantom setup of a knee in a vertical orientation. 72 RSA images were created using different variables for knee orientations, two prosthesis types (fixed-bearing Duracon knee and fixed-bearing Triathlon knee) and accuracies of the reconstruction models. The measurement error was determined for absolute and relative measurements and the effect of knee positioning and true seperation distance was determined. The measurement method overestimated the separation distance with 0.1mm on average. The precision of the method was 0.10mm (2*SD) for the Duracon prosthesis and 0.20mm for the Triathlon prosthesis. A slight difference in error was found between the measurements with 0° and 10° anterior tilt. (difference=0.08mm, p=0.04). The accuracy of 0.1mm and precision of 0.2mm can be achieved for linear wear measurements based on model-based RSA, which is more than adequate for clinical applications. The measurement is robust in clinical settings. Although anterior tilt seems to influence the measurement, the size of this influence is low and clinically irrelevant. Copyright © 2011 Elsevier Ltd. All rights reserved.

Kinematic analysis of anterior cruciate ligament reconstruction in total knee arthroplasty

PubMed Central

Liu, Hua-Wei; Ni, Ming; Zhang, Guo-Qiang; Li, Xiang; Chen, Hui; Zhang, Qiang; Chai, Wei; Zhou, Yong-Gang; Chen, Ji-Ying; Liu, Yu-Liang; Cheng, Cheng-Kung; Wang, Yan

2016-01-01

Background: This study aims to retain normal knee kinematics after knee replacement surgeries by reconstructing anterior cruciate ligament during total knee arthroplasty. Method: We use computational simulation tools to establish four dynamic knee models, including normal knee model, posterior cruciate ligament retaining knee model, posterior cruciate ligament substituting knee model, and anterior cruciate ligament reconstructing knee model. Our proposed method utilizes magnetic resonance images to reconstruct solid bones and attachments of ligaments, and assemble femoral and tibial components according representative literatures and operational specifications. Dynamic data of axial tibial rotation and femoral translation from full-extension to 135 were measured for analyzing the motion of knee models. Findings: The computational simulation results show that comparing with the posterior cruciate ligament retained knee model and the posterior cruciate ligament substituted knee model, reconstructing anterior cruciate ligament improves the posterior movement of the lateral condyle, medial condyle and tibial internal rotation through a full range of flexion. The maximum posterior translations of the lateral condyle, medial condyle and tibial internal rotation of the anterior cruciate ligament reconstructed knee are 15.3 mm, 4.6 mm and 20.6 at 135 of flexion. Interpretation: Reconstructing anterior cruciate ligament in total knee arthroplasty has been approved to be an more efficient way of maintaining normal knee kinematics comparing to posterior cruciate ligament retained and posterior cruciate ligament substituted total knee arthroplasty. PMID:27347334

Improvements in knee biomechanics during walking are associated with increased physical activity after total knee arthroplasty.

PubMed

Arnold, John B; Mackintosh, Shylie; Olds, Timothy S; Jones, Sara; Thewlis, Dominic

2015-12-01

Total knee arthroplasty (TKA) in people with knee osteoarthritis increases knee-specific and general physical function, but it has not been established if there is a relationship between changes in these elements of functional ability. This study investigated changes and relationships between knee biomechanics during walking, physical activity, and use of time after TKA. Fifteen people awaiting TKA underwent 3D gait analysis before and six months after surgery. Physical activity and use of time were determined in free-living conditions from a high resolution 24-h activity recall. After surgery, participants displayed significant improvements in sagittal plane knee biomechanics and improved their physical activity profiles, standing for 105 more minutes (p=0.001) and performing 64 min more inside chores on average per day (p=0.008). Changes in sagittal plane knee range of motion (ROM) and peak knee flexion positively correlated with changes in total daily energy expenditure, time spent undertaking moderate to vigorous physical activity, inside chores and passive transport (r=0.52-0.66, p=0.005-0.047). Restoration of knee function occurs in parallel and is associated with improvements in physical activity and use of time after TKA. Increased functional knee ROM is required to support improvements in total and context specific physical activity. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Backside wear in modern total knee designs.

PubMed

Jayabalan, Prakash; Furman, Bridgette D; Cottrell, Jocelyn M; Wright, Timothy M

2007-02-01

Although modularity affords various options to the orthopedic surgeon, these benefits come at a price. The unintended bearing surface between the back surface of the tibial insert and the metallic tray results in micromotion leading to polyethylene wear debris. The objective of this study was to examine the backside wear of tibial inserts from three modern total knee designs with very different locking mechanisms: Insall-Burstein II (IB II), Optetrak, and Advance. A random sample of 71 inserts were obtained from our institution's retrieval collection and examined to assess the extent of wear, depth of wear, and wear damage modes. Patient records were also obtained to determine patient age, body mass index, length of implantation, and reason for revision. Modes of wear damage (abrasion, burnishing, scratching, delamination, third body debris, surface deformation, and pitting) were then scored in each zone from 0 to 3 (0 = 0%, 1 = 0-10%, 2 = 10-50%, and 3 = >50%). The depth of wear was subjectively identified as removal of manufacturing identification markings stamped onto the inferior surface of the polyethylene. Both Advance and IB II polyethylene inserts showed significantly higher scores for backside wear than the Optetrak inserts. All IB II and Advance implants showed evidence of backside wear, whereas 17% (5 out of 30) of the retrieved Optetrak implants had no observable wear. There were no significant differences when comparing the depth of wear score between designs. The locking mechanism greatly affects the propensity for wear and should be considered when choosing a knee implant system.

Knee joint distraction compared with total knee arthroplasty: a randomised controlled trial.

PubMed

van der Woude, J A D; Wiegant, K; van Heerwaarden, R J; Spruijt, S; Emans, P J; Mastbergen, S C; Lafeber, F P J G

2017-01-01

Knee joint distraction (KJD) is a relatively new, knee-joint preserving procedure with the goal of delaying total knee arthroplasty (TKA) in young and middle-aged patients. We present a randomised controlled trial comparing the two. The 60 patients ≤ 65 years with end-stage knee osteoarthritis were randomised to either KJD (n = 20) or TKA (n = 40). Outcomes were assessed at baseline, three, six, nine, and 12 months. In the KJD group, the joint space width (JSW) was radiologically assessed, representing a surrogate marker of cartilage thickness. In total 56 patients completed their allocated treatment (TKA = 36, KJD = 20). All patient reported outcome measures improved significantly over one year (p < 0.02) in both groups. At one year, the TKA group showed a greater improvement in only one of the 16 patient-related outcome measures assessed (p = 0.034). Outcome Measures in Rheumatology-Osteoarthritis Research Society International clinical response was 83% after TKA and 80% after KJD. A total of 12 patients (60%) in the KJD group sustained pin track infections. In the KJD group both mean minimum (0.9 mm, standard deviation (sd) 1.1) and mean JSW (1.2 mm, sd 1.1) increased significantly (p = 0.004 and p = 0.0003). In relatively young patients with end-stage knee osteoarthritis, KJD did not demonstrate inferiority of outcomes at one year when compared with TKA. However, there is a high incidence of pin track infection associated with KJD. Cite this article: Bone Joint J 2017;99-B:51-8. ©2017 The British Editorial Society of Bone & Joint Surgery.

Fixed-flexion view X-ray of the knee superior in detection and follow-up of knee osteoarthritis

PubMed Central

Kan, Hiroyuki; Arai, Yuji; Kobayashi, Masashi; Nakagawa, Shuji; Inoue, Hiroaki; Hino, Manabu; Komaki, Shintaro; Ikoma, Kazuya; Ueshima, Keiichiro; Fujiwara, Hiroyoshi; Yokota, Isao; Kubo, Toshikazu

2017-01-01

Abstract A fixed flexion view (FFV) is useful for evaluating joint space when assessing the severity of osteoarthritis (OA) of the knee. We analyzed changes in joint space revealed by standing extended view (SEV) and FFV over a mean 4 years, to compare both views on their capacity to measure joint space width accurately at particular time points during follow-up. SEV and FFV images were acquired in patients with knee OA. The 81 patients (157 knees) followed up for ≥24 months were selected as study subjects. Medial joint space widths (MJSW), Kellgren–Lawrence (KL) grades, and reductions in MJSW on SEV (ΔSEV) and FFV (ΔFFV) were compared in knees evaluated by SEV and FFV. At both time-points, mean MJSW was significantly lower by FFV than by SEV. Mean MJSW was significantly lower at follow-up than at first examination by both SEV and FFV. At both time-points, the KL grade was higher by FFV than by SEV group. The ΔFFV was significantly greater than the ΔSEV. ΔSEV did not differ significantly among KL grades, but ΔFFV was significantly greater in patients with KL grade II than in patients with other KL grades. FFV is not only useful for evaluating joint space in knees with OA, but also for accurately evaluating the progression of OA. The risk of rapid progression of knee OA may be higher in patients with KL grade II, as determined by FFV. FFV may be superior to SEV in determining appropriate treatment strategies for knee OA. PMID:29245351

Does increased topside conformity in modular total knee arthroplasty lead to increased backside wear?

PubMed

Schwarzkopf, Ran; Scott, Richard D; Carlson, Evan M; Currier, John H

2015-01-01

Modular metal-backed tibia components allow surgeons intraoperative flexibility. Although it is known that modular tibia components introduce the possibility for backside wear resulting from relative motion between the polyethylene insert and the tibial baseplate, it is not known to what degree variability in the conformity of the tibial polyethylene liner itself might contribute to backside wear. The purpose of this study was to determine whether a flat, cruciate-retaining tibial polyethylene bearing generates less backside wear than a more conforming (curved) tibial polyethylene bearing in an analysis of specimens explanted during revision surgery. The study included 70 total knee inserts explanted at revision surgery, all implanted and explanted by the same surgeon. Two different cruciate-retaining insert options in an otherwise similar knee system were used: one with a curved-on-flat (17) articular geometry and one with a highly conforming curved-on-curved design (53); both groups were sequential cohorts. The composite backside wear depth for the insert as well as the volume of backside wear was measured and compared between groups. The median linear backside-normalized wear for the posterior lipped inserts was 0.0063 mm/year (range, 0-0.085 mm/year), which was lower than for the curved inserts at 0.05 mm/year (range, 0.00003-0.14 mm/year) (p<0.001). The median calculated volumetric backside-normalized wear for the posterior lipped inserts was 14.2 mm3/year (range, 0-282.8 mm3/year) compared with 117 mm3/year (range, 2.1-312 mm3/year) for the curved inserts (p<0.001). In this retrieval study, more conforming tibial inserts demonstrated more backside-normalized wear than the flatter designs. This suggests that in this modular total knee arthroplasty design, higher articular conformity to address the issues of high bearing contact stress comes at a price: increased torque transmitted to the backside insert-to-tray interface. We suggest further work be undertaken

Reducing gender disparities in post-total knee arthroplasty expectations through a decision aid.

PubMed

Volkmann, Elizabeth R; FitzGerald, John D

2015-02-07

Gender disparities in total knee arthroplasty utilization may be due to differences in perceptions and expectations about total knee arthroplasty outcomes. This study evaluates the impact of a decision aid on perceptions about total knee arthroplasty and decision-making parameters among patients with knee osteoarthritis. Patients with moderate to severe knee osteoarthritis viewed a video about knee osteoarthritis treatments options, including total knee arthroplasty, and received a personalized arthritis report. An adapted version of the Western Ontario and McMaster Universities Osteoarthritis Index was used to assess pain and physical function expectations following total knee arthroplasty before/after the intervention. These scores were compared to an age- and gender-adjusted means for a cohort of patients who had undergone total knee arthroplasty. Decision readiness and conflict were also measured. At baseline, both men and women had poorer expectations about post-operative pain and physical outcomes compared with observed outcomes of the comparator group. Following the intervention, women's mean age-adjusted expectations about post- total knee arthroplasty pain outcomes improved (Pre: 27.0; Post: 21.8 [p =0.08; 95% CI -0.7, 11.0]) and were closer to observed post-TKA outcomes; whereas men did not have a significant change in their pain expectations (Pre: 21.3; Post: 19.6 [p = 0.6; 95% CI -5.8, 9.4]). Women also demonstrated a significant improvement in decision readiness; whereas men did not. Both genders had less decision conflict after the intervention. Both women and men with osteoarthritis had poor estimates of total knee arthroplasty outcomes. Women responded to the intervention with more accurate total knee arthroplasty outcome expectations and greater decision readiness. Improving patient knowledge of total knee arthroplasty through a decision aid may improve medical decision-making and reduce gender disparities in total knee arthroplasty utilization.

Vibration arthrometry in the patients with failed total knee replacement.

PubMed

Jiang, C C; Lee, J H; Yuan, T T

2000-02-01

This is a preliminary research on the vibration arthrometry of artificial knee joint in vivo. Analyzing the vibration signals measured from the accelerometer on patella, there are two speed protocols in knee kinematics: 1) 2 degrees/s, the signal is called "physiological patellofemoral crepitus (PPC)", and 2) 67 degrees/s, the signal is called "vibration signal in rapid knee motion". The study has collected 14 patients who had revision total knee arthroplasty due to prosthetic wear or malalignment represent the failed total knee replacement (FTKR), and 12 patients who had just undergone the primary total knee arthroplasty in the past two to six months and have currently no knee pain represent the normal total knee replacement (NTKR). FTKR is clinically divided into three categories: metal wear, polyethylene wear of the patellar component, and no wear but with prosthesis malalignment. In PPC, the value of root mean square (rms) is used as a parameter; in vibration signals in rapid knee motion, autoregressive modeling is used for adaptive segmentation and extracting the dominant pole of each signal segment to calculate the spectral power ratios in f < 100 Hz and f > 500 Hz. It was found that in the case of metal wear, the rms value of PPC signal is far greater than a knee joint with polyethylene wear and without wear, i.e., PPC signal appears only in metal wear. As for vibration signals in rapid knee motion, prominent time-domain vibration signals could be found in the FTKR patients with either polyethylene or metal wear of the patellar component. We also found that for normal knee joint, the spectral power ratio of dominant poles has nearly 80% distribution in f < 100 Hz, is between 50% and 70% for knee with polyethylene wear and below 30% for metal wear, whereas in f > 500 Hz, spectral power ratio of dominant poles has over 30% distribution in metal wear but only nonsignificant distribution in polyethylene wear, no wear, and normal knee. The results show that

Expectations in patients with total knee arthroplasty.

PubMed

Tekin, Burcu; Unver, Bayram; Karatosun, Vasfi

2012-01-01

The primary objective of total knee arthroplasty (TKA) is to decrease pain and restore functional knee joint. Current hypotheses indicate higher knee flexion is required in terms of life style, culture and expectations in Eastern communities. Therefore, society-specific features related to life style and cultural habits are needed. The objective of this study was to investigate the expectations of patients undergoing TKA. The study included 131 patients (18 male, 113 female; mean age: 66.2 ± 8.3 years) who underwent cemented TKA due to knee osteoarthritis. All patients were operated by the same surgeon using the same implant and surgical technique. Patients were evaluated using the Hospital for Special Surgery (HSS) knee score, a 15-item clinical knee assessment questionnaire and the HSS knee arthroplasty expectation questionnaire. Mean HSS score for the right knee was 89.2 ± 10.5 and for the left knee was 89.6 ± 9.4. The two most expected outcomes were improvements in pain (99.2%) and gait (96.2%) and the two least expected outcomes were improvements in psychological well-being (22.9%) and communicative skills (35.1%). Expectations were not affected by education and working conditions. Patients' most expected outcomes were improvement in pain and restoration of function (gait, climbing stairs and no need of assistive devices), similar to Western and American communities.

Impingement of the Mobile Bearing on the Lateral Wall of the Tibial Tray in Unicompartmental Knee Arthroplasty.

PubMed

Inui, Hiroshi; Taketomi, Shuji; Yamagami, Ryota; Sanada, Takaki; Shirakawa, Nobuyuki; Tanaka, Sakae

2016-07-01

Tilting of the mobile bearing relative to the tibial tray in the flexion position may result from the implantation of femoral components more laterally relative to tibial components during unicompartmental knee arthroplasty (UKA) using the Oxford Knee. The purpose of the present study was to compare femoral component positions after UKA using the phase 3 device and a novel device. We further evaluated the placement of the femoral components with the new device in the flexion position to determine the association with short-term prognosis. The location of femoral and tibial components in the flexion position of 38 knees implanted using the phase 3 device and 49 knees using a novel device was assessed at 1 year postoperatively using radiography of the proximal tibia and distal femur in the flexion position. The femoral component was implanted more laterally using the new device than using the phase 3 device in the flexion position (P = .012), which caused the impingement of the mobile bearing against the lateral wall of the tibial tray. After UKA using the new device, 10% of patients exhibited the tilting phenomenon of the mobile bearing because of the lateral implantation of the femoral implant. To prevent implantation of the femoral component too laterally using the new device during UKA, knee surgeons should set the drill guide more medially such that the center of the drill is aligned with the middle of the medial femoral condyle. Copyright © 2016 Elsevier Inc. All rights reserved.

In vivo contact kinematics and contact forces of the knee after total knee arthroplasty during dynamic weight-bearing activities.

PubMed

Varadarajan, Kartik M; Moynihan, Angela L; D'Lima, Darryl; Colwell, Clifford W; Li, Guoan

2008-07-19

Analysis of polyethylene component wear and implant loosening in total knee arthroplasty (TKA) requires precise knowledge of in vivo articular motion and loading conditions. This study presents a simultaneous in vivo measurement of tibiofemoral articular contact forces and contact kinematics in three TKA patients. These measurements were accomplished via a dual fluoroscopic imaging system and instrumented tibial implants, during dynamic single leg lunge and chair rising-sitting. The measured forces and contact locations were also used to determine mediolateral distribution of axial contact forces. Contact kinematics data showed a medial pivot during flexion of the knee, for all patients in the study. Average axial forces were higher for lunge compared to chair rising-sitting (224% vs. 187% body weight). In this study, we measured peak anteroposterior and mediolateral forces averaging 13.3% BW during lunge and 18.5% BW during chair rising-sitting. Mediolateral distributions of axial contact force were both patient and activity specific. All patients showed equitable medial-lateral loading during lunge but greater loads at the lateral compartment during chair rising-sitting. The results of this study may enable more accurate reproduction of in vivo loads and articular motion patterns in wear simulators and finite element models. This in turn may help advance our understanding of factors limiting longevity of TKA implants, such as aseptic loosening and polyethylene component wear, and enable improved TKA designs.

Bilateral custom-fit total knee arthroplasty in a patient with poliomyelitis.

PubMed

Tardy, Nicolas; Chambat, Pierre; Murphy, Colin G; Fayard, Jean-Marie

2014-09-01

In limbs affected by poliomyelitis, total knee arthroplasty results in satisfactory pain relief. However, the risk of failure is high, especially if the preoperative quadriceps power is low. Therefore, treating osteoarthritis in the current patient represented a challenging procedure. A 66-year-old man presented with tricompartmental osteoarthritis of both knees, with valgus deformity of 14° on the left knee and 11° on the right knee. He walked with a bilateral knee recurvatum of 30° and a grade 1 quadriceps power. The authors treated both knees with cemented custom-fit hinged total knee arthroplasty with 30° of recurvatum in the tibial keel. Clinical scores showed good results 1 year postoperatively, especially on the subjective data of quality of life and function. At follow-up, radiographs showed good total knee arthroplasty positioning on the right side and a small mechanical loosening at the end of the tibial keel on the left side. Only 5 studies (Patterson and Insall; Moran; Giori and Lewallen; Jordan et al; and Tigani et al) have reported total knee arthroplasty results in patients with poliomyelitis. This study reports an original case of bilateral custom-fit hinged total knee arthroplasty in a patient with poliomyelitis. To the authors' knowledge, this is the first report of this type of procedure in the literature. The key point is the degree of recurvatum that is needed to allow walking, avoiding excessive constraints on the implants that can lead to early mechanical failure. Copyright 2014, SLACK Incorporated.

Total Knee Replacement

PubMed Central

2005-01-01

Executive Summary Objective The aim of this review was to assess the effectiveness, in terms of pain reduction and functional improvement, and costing of total knee replacement (TKR) for people with osteoarthritis for whom less invasive treatments (such as physiotherapy, analgesics, anti-inflammatory drugs, intra-articular steroids, hyaluronic acids, and arthroscopic surgery) have failed. Clinical Need Osteoarthritis affects an estimated 10% to 12% of Canadian adults. The therapeutic goals of osteoarthritis treatment are to improve joint mobility and reduce pain. Stepwise treatment options include exercise, weight loss, physiotherapy, analgesics, anti-inflammatory drugs, intra-articular steroids and hyaluronic acids, arthroscopic surgery, and, in severe cases, total joint replacement with follow-up rehabilitation. These treatments are delivered by a range of health care professionals, including physiotherapists, occupational therapists, family physicians, internists, rheumatologists, and orthopedic surgeons. TKR is an end-of-line treatment for patients with severe pain and functional limitations. More women than men undergo knee replacement, and most patients are between 55 and 84 years old. The Technology TKR is a surgical procedure in which an artificial joint or prosthesis replaces a damaged knee joint. The primary indication for TKR is pain, followed by functional limitation. Usually, a person’s daily activities must be substantially affected by pain and functional limitations for him or her to be considered a candidate for TKR. There are 3 different types of knee replacement prostheses. Non-constrained prostheses use the patient’s ligaments and muscles to provide the stability for the prosthesis. Semi-constrained prostheses provide some stability for the knee and do not rely entirely on the patient’s ligaments and muscles to provide the stability. Constrained prostheses are for patients whose ligaments and muscles are not able to provide stability for

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... across-the-joint. This generic type of device is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra...

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... across-the-joint. This generic type of device is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra...

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... across-the-joint. This generic type of device is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra...

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... across-the-joint. This generic type of device is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra...

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... across-the-joint. This generic type of device is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra...

14. Detail, typical approach span fixed bearing atop stone masonry ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. Detail, typical approach span fixed bearing atop stone masonry pier, view to northwest, 210mm lens. - Southern Pacific Railroad Shasta Route, Bridge No. 210.52, Milepost 210.52, Tehama, Tehama County, CA

Upright CT of the knee: the effect of weight-bearing on joint alignment.

PubMed

Hirschmann, Anna; Buck, Florian M; Fucentese, Sandro F; Pfirrmann, Christian W A

2015-11-01

To prospectively compare patellofemoral and femorotibial alignment in supine non-weight-bearing computed tomography (NWBCT) and upright weight-bearing CT (WBCT) and assess the differences in joint alignment. NWBCT and WBCT images of the knee were obtained in 26 patients (mean age, 57.0 ± 15.9 years; range, 21-81) using multiple detector CT for NWBCT and cone-beam extremity CT for WBCT. Two musculoskeletal radiologists independently quantified joint alignment by measuring femorotibial rotation, tibial tuberosity-trochlear groove distance (TTTG), lateral patellar tilt angle, lateral patellar shift, and medial and lateral femorotibial joint space widths. Significant differences between NWBCT and WBCT were sought using Wilcoxon signed-rank test (P-value < 0.05). Significant differences were found for femorotibial rotation (the NWBCT mean changed from 2.7° ± 5.1 (reader 1)/2.6° ± 5.6 (reader 2) external rotation to WBCT 0.4° ± 7.7/0.2° ± 7.5 internal rotation; P = 0.009/P = 0.004), TTTG (decrease from NWBCT (13.8 mm ± 5.1/13.9 mm ± 3.9) to WBCT (10.5 mm ± 5.0/10.9 mm ± 5.2; P = 0.008/P = 0.002), lateral patellar tilt angle (decrease from NWBCT (15.6° ± 6.7/16.9° ± 7.4) to WBCT (12.5° ± 7.7/15.0° ± 6.2; P = 0.011/P = 0.188). The medial femorotibial joint space decreased from NWBCT (3.9 mm ± 1.4/4.5 mm ± 1.3) to WBCT (2.9 mm ± 2.2/3.5 mm ± 2.2; P = 0.003/P = 0.004). Inter-reader agreement ranged from 0.52-0.97. Knee joint alignment changes significantly in the upright weight-bearing position using CT when compared to supine non-weight-bearing CT. • Cone-beam extremity CT offers upright weight-bearing examinations of the lower extremities. • Knee alignment changes significantly in an upright position compared to supine position. • Tibial tuberosity-trochlear groove distance (TTTG) is less pronounced in a weight-bearing position. • The

Total knee arthroplasty in a rheumatoid arthritic knee with large geode: a case report.

PubMed

Shih, H N; Hsu, K Y; Tan, C F; Hsueh, S; Hsu, R W

1997-09-01

Geodes (subchondral cysts) are a well-known manifestation of rheumatoid arthritis. Solitary cysts or cysts larger than 2 cm are not generally found in the knee joint of patients with rheumatoid arthritis (RA). We report a case of RA involving both knees with a giant geode over the right proximal tibia. Surgical treatment was performed including synovectomy, cyst enucleation and packing of autogenous bone chips followed by primary total knee arthroplasty. The postsurgical result was excellent with the knee restored to good function and complete healing of the cystic lesion.

[Prevention and repair of patellar ligament injury in total knee arthroplasty].

PubMed

Bian, Yanyan; Weng, Xisheng

2013-09-01

To review the progress in the prevention and repair of patellar ligament injury in total knee Recent literature about the prevention and repair of patellar ligament injury in total knee arthroplasty arthroplasty. was reviewed and analyzed. Increased exposure can prevent the patellar ligament injury, and treatments of acute patellar ligament rupture can be obtained by simple repair, reconstruction with allograft materials or artificial materials, and auxiliary strengthening. Patellar ligament injury in total knee arthroplasty should not be ignored. Active prevention and repair of patellar ligament injury can obtain better function of knee joint.

Difference in knee rotation between total and unicompartmental knee arthroplasties during stair climbing.

PubMed

Jung, Myung-Chul; Chung, Jun Young; Son, Kwang-Hyun; Wang, Hui; Hwang, Jaejin; Kim, Jay Joong; Kim, Joon Ho; Min, Byoung-Hyun

2014-08-01

The purpose of this study was to compare knee kinematics during stair walking in patients with simultaneous total knee arthroplasty (TKA) and unicompartmental knee arthroplasties (UKA). It was hypothesized that UKA would reproduce more normalized knee kinematics than TKA during stair ascent and descent. Six patients who received UKA in one knee and TKA in the other knee were included in the study. For this study, a four-step staircase was assembled with two force platforms being positioned at the centre of the second and third steps. Each patient was attached with 16 reflective markers at both lower extremities and was asked to perform five roundtrip trials of stair climbing. Kinematic parameters including stance duration, knee angle, vertical ground reaction force (GRF), joint reaction force, and moments were obtained and analysed using a10-camera motion system (VICON, Oxford, UK). Nonparametric Friedman test was used to compare the results between two arthroplasty methods and between stair ascent and descent. Compared to TKA, UKA knees exhibited significantly greater degree of rotation in transverse planes (5.0 degrees during ascent and 6.0 degrees during descent on average), but showed no difference in terms of the other parameters. When comparing the results during stair ascent with descent, overall greater knee angle, vertical GRF, joint reaction force, and moment were observed during stair descent. Both UKA and TKA knees have shown overall similar knee kinematics, though UKA knee may allow greater degree of rotation freedom, which resembles normal knee kinematics during stair walking.

Effect of Age on Cost-Effectiveness of Unicompartmental Knee Arthroplasty Compared with Total Knee Arthroplasty in the U.S.

PubMed Central

Ghomrawi, Hassan M.; Eggman, Ashley A.; Pearle, Andrew D.

2015-01-01

Background: Trade-offs between upfront benefits and later risk of revision of unicompartmental knee arthroplasty compared with those of total knee arthroplasty are poorly understood. The purpose of our study was to compare the cost-effectiveness of unicompartmental knee arthroplasty with that of total knee arthroplasty across the age spectrum of patients undergoing knee replacement. Methods: Using a Markov decision analytic model, we compared unicompartmental knee arthroplasty with total knee arthroplasty with regard to lifetime costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) from a societal perspective for patients undergoing surgery at forty-five, fifty-five, sixty-five, seventy-five, or eighty-five years of age. Transition probabilities were estimated from the literature; survival, from the Swedish Knee Arthroplasty Register; and costs, from the literature and the Healthcare Cost and Utilization Project (HCUP) database. Costs and QALYs were discounted at 3.0% annually. We conducted sensitivity analyses to test the robustness of model estimates and threshold analyses. Results: For patients sixty-five years of age and older, unicompartmental knee arthroplasty dominated total knee arthroplasty, with lower lifetime costs and higher QALYs. Unicompartmental knee arthroplasty was no longer cost-effective at a $100,000/QALY threshold when total knee arthroplasty rehabilitation costs were reduced by two-thirds or more for these older patients. Lifetime societal savings from utilizing unicompartmental knee arthroplasty in all older patients (sixty-five or older) in 2015 and 2020 were $56 to $336 million and $84 to $544 million, respectively. In the forty-five and fifty-five-year-old age cohorts, total knee arthroplasty had an ICER of $30,300/QALY and $63,000/QALY, respectively. Unicompartmental knee arthroplasty became cost-effective when its twenty-year revision rate dropped from 27.8% to 25.7% for the forty-five-year age

Combined magnetic resonance imaging approach for the assessment of in vivo knee joint kinematics under full weight-bearing conditions.

PubMed

Al Hares, Ghaith; Eschweiler, Jörg; Radermacher, Klaus

2015-06-01

The development of detailed and specific knowledge on the biomechanical behavior of loaded knee structures has received increased attention in recent years. Stress magnetic resonance imaging techniques have been introduced in previous work to study knee kinematics under load conditions. Previous studies captured the knee movement either in atypical loading supine positions, or in upright positions with help of inclined supporting backrests being insufficient for movement capture under full-body weight-bearing conditions. In this work, we used a combined magnetic resonance imaging approach for measurement and assessment in knee kinematics under full-body weight-bearing in single legged stance. The proposed method is based on registration of high-resolution static magnetic resonance imaging data acquired in supine position with low-resolution data, quasi-static upright-magnetic resonance imaging data acquired in loaded positions for different degrees of knee flexion. The proposed method was applied for the measurement of tibiofemoral kinematics in 10 healthy volunteers. The combined magnetic resonance imaging approach allows the non-invasive measurement of knee kinematics in single legged stance and under physiological loading conditions. We believe that this method can provide enhanced understanding of the loaded knee kinematics. © IMechE 2015.

Polyethylene wear of mobile-bearing unicompartmental knee replacement at 20 years.

PubMed

Kendrick, B J L; Simpson, D J; Kaptein, B L; Valstar, E R; Gill, H S; Murray, D W; Price, A J

2011-04-01

The Oxford unicompartmental knee replacement (UKR) was designed to minimise wear utilising a fully-congruent, mobile, polyethylene bearing. Wear of polyethylene is a significant cause of revision surgery in UKR in the first decade, and the incidence increases in the second decade. Our study used model-based radiostereometric analysis to measure the combined wear of the upper and lower bearing surfaces in 13 medial-compartment Oxford UKRs at a mean of 20.9 years (17.2 to 25.9) post-operatively. The mean linear penetration of the polyethylene bearing was 1.04 mm (0.307 to 2.15), with a mean annual wear rate of 0.045 mm/year (0.016 to 0.099). The annual wear rate of the phase-2 bearings (mean 0.022 mm/year) was significantly less (p = 0.01) than that of phase-1 bearings (mean 0.07 mm/year). The linear wear rate of the Oxford UKR remains very low into the third decade. We believe that phase-2 bearings had lower wear rates than phase-1 implants because of the improved bearing design and surgical technique which decreased the incidence of impingement. We conclude that the design of the Oxford UKR gives low rates of wear in the long term.

Lessons learned from selective soft-tissue release for gap balancing in primary total knee arthroplasty: an analysis of 1216 consecutive total knee arthroplasties: AAOS exhibit selection.

PubMed

Peters, Christopher L; Jimenez, Chris; Erickson, Jill; Anderson, Mike B; Pelt, Christopher E

2013-10-16

Soft-tissue releases are commonly necessary to achieve symmetrical flexion and extension gaps in primary total knee arthroplasty performed with a measured resection technique. We reviewed the frequency of required releases according to preoperative alignment and the clinical and radiographic results; associations with failure, reoperations, and complications are presented. We reviewed 1216 knees that underwent primary total knee arthroplasty from 2004 to 2009; 774 (64%) were in female patients and 442 (36%), in male patients. In the coronal plane, 855 knees had preoperative varus deformity, 123 were neutral, and 238 had valgus deformity. The mean age at the time of the index procedure was 62.7 years (range, twenty-three to ninety-four years), and the mean body mass index was 32.7 kg/m² (range, 17.4 to 87.9 kg/m²). Clinical outcomes included the Knee Society Score (KSS), implant failure, reoperation, and complications. Radiographs were analyzed for component alignment. The only difference in the total KSS was found at the time of final follow-up between valgus knees with zero releases (total KSS = 178) and those with one or two releases (KSS = 160, p = 0.026). Overall, 407 knees (33.5%) required zero releases, 686 (56.4%) required one or two releases, and 123 (10.1%) required three or more releases. Among varus knees, 37% required zero releases, 55% required one or two releases, and 7.5% required three or more releases. Among neutral knees, 39% required zero releases, 55% required one or two releases, and 5.7% required three or more releases. Only 17% of valgus knees required zero releases whereas 61% required one or two releases and 21.8% required three or more releases. Valgus knees required more releases than neutral or varus knees did (p < 0.001). Selective soft-tissue release for gap balancing in primary total knee arthroplasty is an effective technique that produced excellent clinical and radiographic results regardless of preoperative alignment. Consistent

[The application of electroacupuncture to postoperative rehabilitation of total knee replacement].

PubMed

Chen, Gang; Gu, Rui-Xin; Xu, Dan-Dan

2012-04-01

To explore the effect of electroacupuncture therapy for postoperative rehabilitation of total knee replacement of knee osteoarthritis. Seventy cases of total knee replacement of knee osteoarthritis were randomly divided into an acupuncture-rehabilitation group and a rehabilitation group, thirty five cases in each group. In acupuncture-rehabilitation group, routine rehabilitation therapy combined with electroacupuncture therapy was applied. The acupoints selection was mainly based on pathological location; Xuehai (SP 10), Liangqiu (ST 34), Dubi (ST 35), Neixiyan (EX-LE 4) and Yanglingquan (GB 34), etc. were selected. In rehabilitation group, routine rehabilitation therapy was applied. The functions of affected knee in both groups were evaluated by artificial total knee replacement scale of the New York Hospital for Special Surgery (HSS), range of motion (ROM) of affected knee, Visual Analogue Scale (VAS) of pain and Manual Muscle Test (MMT) before, and 2, 6 and 12 weeks after surgery. HSS scores in acupuncture-rehabilitation group were markedly higher than those in rehabilitation group in 2, 6 and 12 weeks after surgery (P < 0.05, P < 0.01); VAS scores in acupuncture-rehabilitation group were markedly lower than those in rehabilitation group (P < 0.05, P < 0.01); ROM and MMT in acupuncture-rehabilitation group were little superior to those in rehabilitation group, however, there was no significant difference (all P > 0.05). Rehabilitation therapy combined with electroacupuncture can obviously restrain the pain during rehabilitation process for total knee replacement patients, improve the endurance capacity of rehabilitation training and motivation, and obviously promote the recovery of total knee joint function.

Long-term outcome of 42 knees with chronic infection after total knee arthroplasty.

PubMed

Bose, W J; Gearen, P F; Randall, J C; Petty, W

1995-10-01

The outcome of treatment in 40 patients (42 knees) with chronic infections after total knee arthroplasty was reviewed. Eighteen knees were treated with a 2-stage reimplantation. Sixteen of these 18 knees were treated with antibiotic-containing beads between debridement and reimplantation, and 7 of these were also treated with antibiotics in the cement at reimplantation. Infection did not recur in any of these 18 knees. Clinically, the 2-stage reimplantation group averaged a score of 90 points on the Knee Society Clinical Rating System. Average function score was 86.5 points, with average range of motion from 2 degrees to 109 degrees. Sixteen knees were treated with an arthrodesis: 9 with a 1-stage technique with a uniplanar external fixator and 7 with a 2-stage technique with intramedullary nail internal fixation. Infection did not recur in 6 of 9 knees treated with the 1-stage technique, but only 2 had a solid arthrodesis. All 7 treated with the 2-stage intramedullary nail technique had no recurrence of infection and achieved a solid fusion. Reimplantation or arthrodesis was not attempted in 8 other knees because of recalcitrant infection, vascular complications, or medical infirmity. Of the 42 knees, 11 (26%) had a severely morbid outcome. The infection could not be eradicated in 7 knees: 6 required amputation and 1 had a solid fusion but chronic drainage. In 3 knees, the infection was cured but resection arthroplasties were required, and in 1 patient an amputation was needed as a result of an intraoperative vascular complication.

[Restricted motion after total knee arthroplasty].

PubMed

Kucera, T; Urban, K; Karpas, K; Sponer, P

2007-10-01

The aim of the study was to ascertain what proportion of patients undergoing total knee arthroplasty (TKA) complain of restricted knee joint motion, and to investigate options for improvement of this situation. Our evaluation included a group of 796 patients treated with TKA at our department in the period from January 1, 1990, to December 31, 2004. In all cases, a condylar implant with preservation of the posterior cruciate ligaments was used. In addition to medical history, the range of motion, knee joint malalignment and radiological findings were assessed before surgery. After THA, the type of implant and complications, if any, were recorded, and improvement in joint motion was followed up. Based on the results of Kim et al., flexion contracture equal to or higher than 15 degrees and/or flexion less than 75 degrees were made the criteria of stiffness after THA. Patients with restricted THA motion who had aseptic or septic implant loosening were not included. Of the 796 evaluated patients, 32 (4.14 %) showed restricted motion after total knee arthroplasty, as assessed by the established criteria. In 16 patients, stiffness defined by these criteria had existed before surgery, and three patients showed an excessive production of adhesions and heterotopic ossifications. In three patients, the implantation procedure resulted in an elevated level of the original joint line and subsequent development of patella infera and increased tension of the posterior cruciate ligament. Four patients declined physical therapy and, in six, the main cause of stiffness could not be found. Seventeen patients did not require surgical therapy for restricted motion; TKA provided significant pain relief and they considered the range of motion achieved to be sufficient. One patient underwent redress 3 months after surgery, but with no success. Repeated releases of adhesions, replacement of a polyethylene liner and revision surgery of the extensor knee structures were performed in 15

Autologous blood transfusion in total knee replacement surgery.

PubMed

Sarkanović, Mirka Lukić; Gvozdenović, Ljiljana; Savić, Dragan; Ilić, Miroslav P; Jovanović, Gordana

2013-03-01

Total knee replacement (TKR) surgery is one of the most frequent and the most extensive procedures in orthopedic surgery, accompanied with some serious complications. Perioperative blood loss is one of the most serious losses, so it is vital to recognize and treat such losses properly. Autologous blood transfusion is the only true alternative for the allogeneic blood. The aim of this study was to to examine if autologous blood transfusion reduces usage of allogenic blood in total knee replacement surgery, as well as to examine possible effect of autologous blood transfusion on postoperative complications, recovery and hospital stay of patients after total knee replacement surgery. During the controlled, prospective, randomised study we compared two groups of patients (n = 112) with total prosthesis implanted in their knee. The group I consisted of the patients who received the transfusion of other people's (allogeneic) blood (n = 57) and the group II of the patients whose blood was collected postoperatively and then given them [their own (autologous) blood] (n = 55). The transfusion trigger for both groups was hemoglobin level of 85 g/L. In the group of patients whose blood was collected perioperatively only 9 (0.9%) of the patients received transfusion of allogeneic blood, as opposed to the control group in which 98.24% of the patients received the transfusion of allogeneic blood (p < or = 0.01). The patients whose blood was collected stayed in hospital for 6.18 days, while the patients of the control group stayed 7.67 days (p < 0.01). Autologous blood transfusion is a very effective method for reducing consumption of allogenic blood and thus, indirectly for reducing all complications related to allogenic blood transfusion. There is also a positive influence on postoperative recovery after total knee replacement surgery due to the reduction of hospital stay, and indirectly on the reduction of hospital costs.

Retention of the posterior cruciate ligament versus the posterior stabilized design in total knee arthroplasty: a prospective randomized controlled clinical trial

PubMed Central

van den Boom, Lennard GH; Brouwer, Reinoud W; van den Akker-Scheek, Inge; Bulstra, Sjoerd K; van Raaij, Jos JAM

2009-01-01

Background Prosthetic design for the use in primary total knee arthroplasty has evolved into designs that preserve the posterior cruciate ligament (PCL) and those in which the ligament is routinely sacrificed (posterior stabilized). In patients with a functional PCL the decision which design is chosen depends largely on the favour and training of the surgeon. The objective of this study is to determine whether the patient's perceived outcome and speed of recovery differs between a posterior cruciate retaining total knee arthroplasty and a posterior stabilized total knee arthroplasty. Methods/Design A randomized controlled trial will be conducted. Patients who are admitted for primary unilateral TKA due to primary osteoarthrosis are included when the following inclusion criteria are met: non-fixed fixed varus or valgus deformity less than 10 degrees, age between 55 and 85 years, body mass index less than 35 kg/m2 and ASA score (American Society of Anaesthesiologists) I or II. Patients are randomized in 2 groups. Patients in the posterior cruciate retaining group will receive a prosthesis with a posterior cut-out for the posterior cruciate ligament and relatively flat topography. In patients allocated to the posterior stabilized group, in which the posterior cruciate ligament is excised, the design may substitute for this function by an intercondylar tibial prominence that articulates with the femur in flexion. Measurements will take place preoperatively and 6 weeks, 3 months, 6 months and 1 year postoperatively. At all measurement points patient's perceived outcome will be assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Secondary outcome measures are quality of life (SF-36) and physician reported functional status and range of motion as determined with the Knee Society Clinical Rating System (KSS). Discussion In the current practice both posterior cruciate retaining and posterior stabilized designs for total knee

Knee extension range of motion and self-report physical function in total knee arthroplasty: mediating effects of knee extensor strength

PubMed Central

2013-01-01

Background Knee extensor strength and knee extension range of motion (ROM) are important predictors of physical function in patients with a total knee arthroplasty (TKA). However, the relationship between the two knee measures remains unclear. The purpose of this study was to examine whether changes in knee extensor strength mediate the association between changes in knee extension ROM and self-report physical function. Methods Data from 441 patients with a TKA were collected preoperatively and 6 months postoperatively. Self-report measure of physical function was assessed by the Short Form 36 (SF-36) questionnaire. Knee extensor strength was measured by handheld dynamometry and knee extension ROM by goniometry. A bootstrapped cross product of coefficients approach was used to evaluate mediation effects. Results Mediation analyses, adjusted for clinicodemographic measures, revealed that the association between changes in knee extension ROM and SF-36 physical function was mediated by changes in knee extensor strength. Conclusions In patients with TKA, knee extensor strength mediated the influence of knee extension ROM on physical function. These results suggest that interventions to improve the range of knee extension may be useful in improving knee extensor performance. PMID:23332039

Detection of total knee prostheses at airport security checkpoints.

PubMed

Naziri, Qais; Johnson, Aaron J; Hooper, Hasan A; Sana, Said H; Mont, Michael A

2012-06-01

Airport security screening measures have changed substantially during the past decade, but few reports have examined how this affects patients who have undergone knee arthroplasties. The purpose of this study was to characterize the efficacy of airport metal detection of total knee prostheses, the delays faced, any inconvenience this may have caused, and the role of implant identification cards. Ninety-seven total knee arthroplasty recipients reported passing through an airport metal detector, with 70 triggering the alarm a mean of 3 times (range, 1-36). The presence of a single-knee prosthesis triggered airport security alarms more than 83% of the time and increased patient inconvenience. Patients should be informed about this chance and be prepared to present documentation of their prosthesis. Copyright © 2012 Elsevier Inc. All rights reserved.

Total knee arthroplasty following prior distal femoral fracture.

PubMed

Papadopoulos, Elias C; Parvizi, Javad; Lai, Choon H; Lewallen, David G

2002-12-01

Femoral fracture may predispose the knee to the development of post-traumatic arthritis by either a direct intra-articular injury or residual limb malalignment. Malunion, intra-articular osseous defects, limb malalignment, retained internal fixation devices, and compromised surrounding soft tissues may in turn affect the outcome of total knee arthroplasty (TKA) in these patients. The aim of our study was to evaluate the result of TKA in patients with previous distal femoral fracture. The results of 48 cemented condylar total knee arthroplasties, performed between 1980 to 1998, in 47 patients with a previous distal femoral fracture were reviewed. There were 37 females and 10 males with an average age of 65 years (range, 19-84 years). Follow-up averaged 6.2 years (range, 2-16 years). No patients were lost to follow-up. At the time of arthroplasty a femoral fracture non-union was present in three knees, all of which were treated with a long stem cemented femoral component and bone grafting. Malunion, defined as angulation greater than 10 degrees in the coronal plain or greater than 15 degrees in the sagittal plain, was present in 21 knees. Of these, six underwent distal femoral osteotomy during TKA. In the remaining 15 patients, with a malunion, the deformity was addressed by alterations in the orientation and location of bone resection. Other procedures were commonly needed at the time of arthroplasty and included: lateral retinacular release (22 knees), extensor mechanism realignment (eight knees), and collateral ligament reconstruction (two knees). The mean pre-operative Knee Society Scores were 40 (range, 0-80) for pain and 48 (range, 0-100) for function and improved significantly to a mean of 84 (range, 37-99) and 66 (range, 0-100) points, respectively, at the latest follow-up (P<0.001). The knee arc of motion improved from a pre-operative mean of 83-99 degrees at the latest follow-up (P<0.004). Post-operative manipulation under anesthesia for poor motion was

Effect of rotational alignment on outcome of total knee arthroplasty

PubMed Central

Breugem, Stefan J; van den Bekerom, Michel PJ; Tuinebreijer, Willem E; van Geenen, Rutger C I

2015-01-01

Background and purpose Poor outcomes have been linked to errors in rotational alignment of total knee arthroplasty components. The aims of this study were to determine the correlation between rotational alignment and outcome, to review the success of revision for malrotated total knee arthroplasty, and to determine whether evidence-based guidelines for malrotated total knee arthroplasty can be proposed. Patients and methods We conducted a systematic review including all studies reporting on both rotational alignment and functional outcome. Comparable studies were used in a correlation analysis and results of revision were analyzed separately. Results 846 studies were identified, 25 of which met the inclusion criteria. From this selection, 11 studies could be included in the correlation analysis. A medium positive correlation (ρ = 0.44, 95% CI: 0.27–0.59) and a large positive correlation (ρ = 0.68, 95% CI: 0.64–0.73) were found between external rotation of the tibial component and the femoral component, respectively, and the Knee Society score. Revision for malrotation gave positive results in all 6 studies in this field. Interpretation Medium and large positive correlations were found between tibial and femoral component rotational alignment on the one hand and better functional outcome on the other. Revision of malrotated total knee arthroplasty may be successful. However, a clear cutoff point for revision for malrotated total knee arthroplasty components could not be identified. PMID:25708694

Comparison of cemented and uncemented fixation in total knee arthroplasty.

PubMed

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

2013-05-01

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

Posterior dislocation following revision total knee replacement arthroplasty: a case report and literature analysis.

PubMed

Lee, Ho Min; Kim, Jong Pil; Chung, Phil Hyun; Kang, Suk; Kim, Young Sung; Go, Bo Seong

2018-05-24

Knee dislocation following total knee replacement arthroplasty is a rare but serious complication. The incidence of dislocation following primary total knee arthroplasty with posterior stabilized implants ranges from 0.15 to 0.5%, and posterior dislocation after revision total knee arthroplasty is even rarer. Here, we report the case of a 76-year-old male who presented with posterior dislocation after posterior stabilized revision total knee arthroplasty.

Anteroposterior translation and range of motion after total knee arthroplasty using posterior cruciate ligament-retaining versus posterior cruciate ligament-substituting prostheses.

PubMed

Ishii, Yoshinori; Noguchi, Hideo; Sato, Junko; Sakurai, Tetsuya; Toyabe, Shin-Ichi

2017-11-01

It is still controversial whether anteroposterior (AP) translation magnitude after total knee arthroplasty (TKA) affects clinical outcomes, particularly range of motion (ROM). This study examined the following two questions: (1) are AP translations at the mid- and long-term follow-up different for knees within the same patient treated with posterior cruciate ligament-retaining (PCLR) versus posterior cruciate ligament-substituting (PCLS) mobile-bearing TKA prosthesis designs? (2) Is the ROM at the mid- and long-term follow-up for knees treated with PCLR and PCLS designs correlated with the AP translation? Thirty-seven patients undergoing sequential bilateral TKA for osteoarthritis were prospectively enrolled. Patients received a PCLR implant in one knee and a PCLS implant in the other and were followed-up for an average 9.8 ± 3.2 years. The AP translations at 30° and 75° of knee flexion and the ROM of both knees were assessed. The implant design (p < 0.001), but not flexion angle (n.s.), had a significant effect on AP translation. AP translation values were larger in PCLR knees than in PCLS knees at both flexion angles (p < 0.0001). The ROM at the final follow-up in the two implant designs was similar (both 115°, n.s.). There was a weak correlation between ROM and AP translation at 30° in the PCLR knees (r = 0.397, p = 0.015), but no correlation at 75° or in the PCLS knees. Differently constrained prosthesis designs resulted in significantly different AP translational values within the same patient. This indicates that achieving good clinical outcomes and ROM after TKA may not be strongly influenced by the specifics of each patient's anatomical characteristics, but instead by knee constrainment. Clinically, this means that surgeons should familiarize themselves with the AP translation of the implant being used, as this may be the most important factor for optimizing outcomes after mobile-bearing TKA. Level of evidence II, prospective, comparative

Displays mounted on cutting blocks reduce the learning curve in navigated total knee arthroplasty.

PubMed

Schnurr, Christoph; Eysel, Peer; König, Dietmar Pierre

2011-01-01

The use of computer navigation in total knee arthroplasty (TKA) improves the implant alignment but increases the operation time. Studies have shown that the operation time is further prolonged due to the surgeon's learning curve, and longer operation times have been associated with higher morbidity risks. It has been our hypothesis that an improvement in the human-machine interface might reduce the time required during the learning curve. Accordingly, we asked whether the use of navigation devices with a display fixed on the surgical instruments would reduce the operation time in navigated TKAs performed by navigation beginners. Thirty medical students were randomized and used two navigation devices in rotation: these were the Kolibri® device with an external display and the Dash® device with a display that was fixed on the cutting blocks. The time for adjustment of the tibial and femoral cutting blocks on knee models while using these devices was measured. A significant time reduction was demonstration when the Dash® device was used: The time reduction was 21% for the tibial block (p = 0.007), 40% for the femoral block (p < 0.001), and 32% for the whole procedure (p < 0.001). The integrated display, fixed on surgical instruments in a manner similar to a spirit level, seems to be more user-friendly for navigation beginners. Hence, unproductive time losses during the learning curve may be diminished.

Total knee arthroplasty and fractures of the tibial plateau

PubMed Central

Softness, Kenneth A; Murray, Ryan S; Evans, Brian G

2017-01-01

Tibial plateau fractures are common injuries that occur in a bimodal age distribution. While there are various treatment options for displaced tibial plateau fractures, the standard of care is open reduction and internal fixation (ORIF). In physiologically young patients with higher demand and better bone quality, ORIF is the preferred method of treating these fractures. However, future total knee arthroplasty (TKA) is a consideration in these patients as post-traumatic osteoarthritis is a common long-term complication of tibial plateau fractures. In older, lower demand patients, ORIF is potentially less favorable for a variety of reasons, namely fixation failure and the need for delayed weight bearing. In some of these patients, TKA can be considered as primary mode of treatment. This paper will review the literature surrounding TKA as both primary treatment and as a salvage measure in patients with fractures of the tibial plateau. The outcomes, complications, techniques and surgical challenges are also discussed. PMID:28251061

Multimodal analgesia without parenteral narcotics for total knee arthroplasty.

PubMed

Dorr, Lawrence D; Raya, Julio; Long, William T; Boutary, Myriam; Sirianni, Leigh Ellen

2008-06-01

Use of parenteral narcotics after total knee arthroplasty is considered by most orthopedic surgeons to be the standard of care. This study tested the hypothesis that a multimodal oral pain medication protocol could control pain and minimize complications of parenteral narcotics. Postoperative oral analgesia was augmented with either continuous epidural infusion or continuous femoral infusion using ropivacaine only. Seventy patients had total knee arthroplasty with a protocol that included preemptive oral analgesics, epidural anesthesia, pericapsular analgesic injection, and postoperative analgesia without parenteral opioids. The average daily pain score was less than 4 out of 10, nausea occurred in 15 patients (21%), emesis in 1 patient (1.4%), and there were no severe complications. This study proved the hypothesis that pain after total knee arthroplasty could be effectively managed without routine use of parenteral opioids.

Improved knee biomechanics among patients reporting a good outcome in knee-related quality of life one year after total knee arthroplasty.

PubMed

Naili, Josefine E; Wretenberg, Per; Lindgren, Viktor; Iversen, Maura D; Hedström, Margareta; Broström, Eva W

2017-03-21

It is not well understood why one in five patients report poor outcomes following knee arthroplasty. This study evaluated changes in knee biomechanics, and perceived pain among patients reporting either a good or a poor outcome in knee-related quality of life after total knee arthroplasty. Twenty-eight patients (mean age 66 (SD 7) years) were included in this prospective study. Within one month of knee arthroplasty and one year after surgery, patients underwent three-dimensional (3D) gait analysis, completed the Knee Injury and Osteoarthritis Outcome Score (KOOS), and rated perceived pain using a visual analogue scale. A "good outcome" was defined as a change greater than the minimally detectable change in the KOOS knee-related quality of life, and a "poor outcome" was defined as change below the minimally detectable change. Nineteen patients (68%) were classified as having a good outcome. Groups were analyzed separately and knee biomechanics were compared using a two-way repeated measures ANOVA. Differences in pain between groups were evaluated using Mann Whitney U test. Patients classified as having a good outcome improved significantly in most knee gait biomechanical outcomes including increased knee flexion-extension range, reduced peak varus angle, increased peak flexion moment, and reduced peak valgus moment. The good outcome group also displayed a significant increase in walking speed, a reduction (normalization) of stance phase duration (% of gait cycle) and increased passive knee extension. Whereas, the only change in knee biomechanics, one year after surgery, for patients classified as having a poor outcome was a significant reduction in peak varus angle. No differences in pain postoperatively were found between groups. Patients reporting a good outcome in knee-related quality of life improved in knee biomechanics during gait, while patients reporting a poor outcome, despite similar reduction in pain, remained unchanged in knee biomechanics one year after

Instability following total knee arthroplasty.

PubMed

Rodriguez-Merchan, E Carlos

2011-10-01

Background Knee prosthesis instability (KPI) is a frequent cause of failure of total knee arthroplasty. Moreover, the degree of constraint required to achieve immediate and long-term stability in total knee arthroplasty (TKA) is frequently debated. Questions This review aims to define the problem, analyze risk factors, and review strategies for prevention and treatment of KPI. Methods A PubMed (MEDLINE) search of the years 2000 to 2010 was performed using two key words: TKA and instability. One hundred and sixty-five initial articles were identified. The most important (17) articles as judged by the author were selected for this review. The main criteria for selection were that the articles addressed and provided solutions to the diagnosis and treatment of KPI. Results Patient-related risk factors predisposing to post-operative instability include deformity requiring a large surgical correction and aggressive ligament release, general or regional neuromuscular pathology, and hip or foot deformities. KPI can be prevented in most cases with appropriate selection of implants and good surgical technique. When ligament instability is anticipated post-operatively, the need for implants with a greater degree of constraint should be anticipated. In patients without significant varus or valgus malalignment and without significant flexion contracture, the posterior cruciate ligament (PCL) can be retained. However, the PCL should be sacrificed when deformity exists particularly in patients with rheumatoid arthritis, previous patellectomy, previous high tibial osteotomy or distal femoral osteotomy, and posttraumatic osteoarthritis with disruption of the PCL. In most cases, KPI requires revision surgery. Successful outcomes can only be obtained if the cause of KPI is identified and addressed. Conclusions Instability following TKA is a common cause of the need for revision. Typically, knees with deformity, rheumatoid arthritis, previous patellectomy or high tibial osteotomy, and

Stiffness after total knee arthroplasty.

PubMed

Manrique, Jorge; Gomez, Miguel M; Parvizi, Javad

2015-04-01

Stiffness after total knee arthroplasty (TKA) adversely affects outcome and impacts patient function. Various risk factors for stiffness after TKA have been identified, including reduced preoperative knee range of motion, history of prior knee surgery, etiology of arthritis, incorrect positioning or oversizing of components, and incorrect gap balancing. Mechanical and associated causes, such as infection, arthrofibrosis, complex regional pain syndrome, and heterotopic ossification, secondary gain issues have also been identified. Management of stiffness following TKA can be challenging. The condition needs to be assessed and treated in a staged manner. A nonsurgical approach is the first step. Manipulation under anesthesia may be considered within the first 3 months after the index TKA, if physical therapy fails to improve the range of motion. Beyond this point, consideration should be given to surgical intervention such as lysis of adhesions, either arthroscopically or by open arthrotomy. If the cause of stiffness is deemed to be surgical error, such as component malpositioning, revision arthroplasty is indicated. The purpose of this article is to evaluate the various aspects of management of stiffness after TKA. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Knee stability before and after total and unicondylar knee replacement: in vivo kinematic evaluation utilizing navigation.

PubMed

Casino, Daniela; Martelli, Sandra; Zaffagnini, Stefano; Lopomo, Nicola; Iacono, Francesco; Bignozzi, Simone; Visani, Andrea; Marcacci, Maurilio

2009-02-01

Surgical navigation systems are currently used to guide the surgeon in the correct alignment of the implant. The aim of this study was to expand the use of navigation systems by proposing a surgical protocol for intraoperative kinematics evaluations during knee arthroplasty. The protocol was evaluated on 20 patients, half undergoing unicondylar knee arthroplasty (UKA) and half undergoing posterior-substituting, rotating-platform total knee arthroplasty (TKA). The protocol includes a simple acquisition procedure and an original elaboration methodology. Kinematic tests were performed before and after surgery and included varus/valgus stress at 0 and 30 degrees and passive range of motion. Both UKA and TKA improved varus/valgus stability in extension and preserved the total magnitude of screw-home motion during flexion. Moreover, compared to preoperative conditions, values assumed by tibial axial rotation during flexion in TKA knees were more similar to the rotating patterns of UKA knees. The analysis of the anteroposterior displacement of the knee compartments confirmed that the two prostheses did not produce medial pivoting, but achieved a postoperative normal behavior. These results demonstrated that proposed intraoperative kinematics evaluations by a navigation system provided new information on the functional outcome of the reconstruction useful to restore knee kinematics during surgery.

Position controlled Knee Rehabilitation Orthotic Device for Patients after Total Knee Replacement Arthroplasty

NASA Astrophysics Data System (ADS)

Wannaphan, Patsiri; Chanthasopeephan, Teeranoot

2016-11-01

Knee rehabilitation after total knee replacement arthroplasty is essential for patients during their post-surgery recovery period. This study is about designing one degree of freedom knee rehabilitation equipment to assist patients for their post-surgery exercise. The equipment is designed to be used in sitting position with flexion/extension of knee in sagittal plane. The range of knee joint motion is starting from 0 to 90 degrees angle for knee rehabilitation motion. The feature includes adjustable link for different human proportions and the torque feedback control at knee joint during rehabilitation and the control of flexion/extension speed. The motion of the rehabilitation equipment was set to move at low speed (18 degrees/sec) for knee rehabilitation. The rehabilitation link without additional load took one second to move from vertical hanging up to 90° while the corresponding torque increased from 0 Nm to 2 Nm at 90°. When extra load is added, the link took 1.5 seconds to move to 90° The torque is then increased from 0 Nm to 4 Nm. After a period of time, the speed of the motion can be varied. User can adjust the motion to 40 degrees/sec during recovery activity of the knee and users can increase the level of exercise or motion up to 60 degrees/sec to strengthen the muscles during throughout their rehabilitation program depends on each patient. Torque control is included to prevent injury. Patients can use the equipment for home exercise to help reduce the number of hospital visit while the patients can receive an appropriate therapy for their knee recovery program.

Avulsion of the fibular head post-total knee replacement.

PubMed

Phadnis, Ashish; Johnston, Phillip; Glasgow, Malcom

2007-11-01

We report a case of an avulsion of part of the fibular head during a primary total knee replacement for osteoarthritis. Post-operatively the patient developed a foot-drop. However, there was no clinically demonstrable instability of the knee. The patient was managed conservatively, the foot-drop recovered completely and the knee remained clinically stable. We observed that excessive hyperextension and/or a varus strain on the knee during pressurisation while cementing could have led to the injury. We advise caution while using this manoeuvre for pressurisation. This is the first injury of its kind reported in the literature.

Human knee joint anatomy revisited: morphometry in the light of sex-specific total knee arthroplasty.

PubMed

Dargel, Jens; Michael, Joern W P; Feiser, Janna; Ivo, Roland; Koebke, Juergen

2011-04-01

This study investigates differences in the anatomy of male and female knee joints to contribute to the current debate on sex-specific total knee implants. Morphometric data were obtained from 60 human cadaver knees, and sex differences were calculated. All data were corrected for height, and male and female specimens presenting with an identical length of the femur were analyzed as matched pairs. Male linear knee joint dimensions were significantly larger when compared with females. When corrected for differences in height, medial-lateral dimensions of male knees were significantly larger than female; however, matched paired analysis did not prove these differences to be consistent. Although implant design should focus interindividual variations in knee joint anatomy, our data do not support the concept of a female-specific implant design. Copyright © 2011 Elsevier Inc. All rights reserved.

Reverse Engineering Nature to Design Biomimetic Total Knee Implants.

PubMed

Varadarajan, Kartik Mangudi; Zumbrunn, Thomas; Rubash, Harry E; Malchau, Henrik; Muratoglu, Orhun K; Li, Guoan

2015-10-01

While contemporary total knee arthroplasty (TKA) provides tremendous clinical benefits, the normal feel and function of the knee is not fully restored. To address this, a novel design process was developed to reverse engineer "biomimetic" articular surfaces that are compatible with normal soft-tissue envelope and kinematics of the knee. The biomimetic articular surface is created by moving the TKA femoral component along in vivo kinematics of normal knees and carving out the tibial articular surface from a rectangular tibial block. Here, we describe the biomimetic design process. In addition, we utilize geometric comparisons and kinematic simulations to show that; (1) tibial articular surfaces of conventional implants are fundamentally incompatible with normal knee motion, and (2) the anatomic geometry of the biomimetic surface contributes directly to restoration of normal knee kinematics. Such biomimetic implants may enable us to achieve the long sought after goal of a "normal" knee post-TKA surgery. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

PERIPROSTHETIC FRACTURES IN TOTAL KNEE ARTHROPLASTY

PubMed Central

de Alencar, Paulo Gilberto Cimbalista; De Bortoli, Giovani; Ventura Vieira, Inácio Facó; Uliana, Christiano Saliba

2015-01-01

The increasing number of total knee arthroplasties, in combination with the population's longer life expectancy, has led to a greater number of long-term complications. These add to the poor bone quality of elderly patients and often culminate in periprosthetic fractures. This complex orthopedic problem has a great diversity of clinical presentation. It may affect any of the bones in the knee and, because of the difficulty in finding solutions, may lead to disastrous outcomes. Its treatment requires that orthopedists should have broad knowledge both of arthroplasty techniques and of osteosynthesis, as well as an elaborate therapeutic arsenal including, for example, access to a bone bank. PMID:27022546

Strategies for reducing implant costs in the revision total knee arthroplasty episode of care.

PubMed

Elbuluk, Ameer M; Old, Andrew B; Bosco, Joseph A; Schwarzkopf, Ran; Iorio, Richard

2017-12-01

Implant price has been identified as a significant contributing factor to high costs associated with revision total knee arthroplasty (rTKA). The goal of this study is to analyze the cost of implants used in rTKAs and to compare this pricing with 2 alternative pricing models. Using our institutional database, we identified 52 patients from January 1, 2014 to December 31, 2014. Average cost of components for each case was calculated and compared to the total hospital cost for that admission. Costs for an all-component revision were then compared to a proposed "direct to hospital" (DTH) standardized pricing model and a fixed price revision option. Potential savings were calculated from these figures. On average, 28% of the total hospital cost was spent on implants for rTKA. The average cost for revision of all components was $13,640 and ranged from $3000 to $28,000. On average, this represented 32.7% of the total hospital cost. Direct to hospital implant pricing could potentially save approximately $7000 per rTKA, and the fixed pricing model could provide a further $1000 reduction per rTKA-potentially saving $8000 per case on implants alone. Alternative implant pricing models could help lower the total cost of rTKA, which would allow hospitals to achieve significant cost containment.

Why total knees fail-A modern perspective review.

PubMed

Lum, Zachary C; Shieh, Alvin K; Dorr, Lawrence D

2018-04-18

Historically, the most common mechanism of total knee arthroplasty (TKA) failures included aseptic loosening, instability and malalignment. As polyethylene production improved, modes of failure from polyethylene wear and subsequent osteolysis became less prevalent. Newer longitudinal studies report that infection has become the primary acute cause of failure with loosening and instability remaining as the overall greatest reasons for revision. Clinical database and worldwide national registries confirm these reports. With an increasing amount of TKA operations performed in the United States, and with focus on value-based healthcare, it is imperative to understand why total knees fail.

Impact of Soft Tissue Imbalance on Knee Flexion Angle After Posterior Stabilized Total Knee Arthroplasty.

PubMed

Tsukada, Sachiyuki; Fujii, Tomoko; Wakui, Motohiro

2017-08-01

This study was performed to assess the impact of soft tissue imbalance on the knee flexion angle 2 years after posterior stabilized total knee arthroplasty (TKA). A total of 329 consecutive varus knees were included to assess the association of knee flexion angle 2 years after TKA with preoperative, intraoperative, and postoperative variables. All intraoperative soft tissue measurements were performed by a single surgeon under spinal anesthesia in a standardized manner including the subvastus approach, reduced patella, and without use of a pneumonic tourniquet. Multiple linear regression analysis showed no significant correlations in terms of intraoperative valgus imbalance at 90-degree flexion or the difference in soft tissue tension between 90-degree flexion and 0-degree extension (β = -0.039; 95% confidence interval [CI], -0.88 to 0.80; P = .93 and β = 0.015; 95% CI, -0.29 to 0.32; P = .92, respectively). Preoperative flexion angle was significantly correlated with knee flexion angle 2 years after TKA (β = 0.42; 95% CI, 0.33 to 0.51; P < .0001). Avoiding valgus imbalance at 90-degree flexion and aiming for strictly equal soft tissue tension between 90-degree flexion and 0-degree extension had little practical value with regard to knee flexion angle 2 years after posterior stabilized TKA. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

[Knee disarticulation and through-knee amputation].

PubMed

Baumgartner, R

2011-10-01

A knee disarticulation or a through-knee stump is superior compared to a transfemoral stump. The thigh muscles are all preserved, and the muscle balance remains undisturbed. The range of motion of the hip joint is not limited. The bulbous shape of the stump allows full weight bearing at the stump end and can easily be fitted with a prosthesis. An amputee with a bilateral knee disarticulation is able to walk "barefoot". A more distal amputation level, e.g., an ultra-short transtibial amputation, is not possible. Important alternative to transfemoral amputations. Possible for any etiology except for Buerger-Winiwarter's disease. New indications are infected and loosened total knee replacements. Preservation of the knee joint is possible. Knee disarticulation is a very atraumatic procedure, compared to transfemoral amputations. Neither bones nor muscles have to be severed, just skin, ligaments, vessels, and nerves. Even the meniscal cartilages may be left in place to act as axial shock absorbers. The cartilage of the femur is not resected, but only bevelled in case of osteoarthritis. There are no tendon attachments or myoplastic procedures necessary. The patella remains in place and is held in position only by the retinacula. Skin closure must be performed without the slightest tension, and if possible not in the weight-bearing area. Transcondylar amputations across the femoral condyles only are indicated when there are not sufficient soft tissues for wound closure of a knee disarticulation. Alternatives as the techniques of Gritti, Klaes, and Eigler, the shortening of the femur and the Sauerbruch's rotation plasty [14] are presented and discussed. The risk of decubital ulcers is rather high. Correct bandaging of the stump is, therefore, particularly important. Prosthetic fitting is possible 3-6 weeks after surgery. The type of prosthesis depends on the amputee's activity level. The superior performance of amputees with knee disarticulations in sports prove the

Arthroscopic treatment of patients with moderate arthrofibrosis after total knee replacement.

PubMed

Jerosch, Joerg; Aldawoudy, Akram M

2007-01-01

The purpose of this study was to document the effect of arthroscopic management in patients with knee stiffness after total knee replacement. We present a case series study, in which 32 patients have been treated for moderate arthrofibrosis of the knee after total knee replacement, with the same regimen. We have excluded all cases of stiffness, because of infection, mechanical mal-alignment, loosening of the implants and other obvious reasons of stiffness of the knee, rather than pure arthrofibrosis. All patients first underwent a trial of conservative treatment before going for arthroscopic management. A pain catheter for femoral nerve block was inserted just before anesthesia for post-operative pain management. Arthroscopic arthrolysis of the intra-articular pathology was performed in a standardized technique with release of all fibrous bands in the suprapatellar pouch, reestablishing the medial and lateral gutter, release of the patella, resection of the remaining meniscal tissue or an anterior cyclops, if needed. Intensive physiotherapy and continuous passive motion were to start immediately post-operatively. All the patients were available for the follow up and they were evaluated using the knee society rating system. A total of 25 of the 32 procedures resulted in an improvement of the patients knee score. All the knees operated upon had intra-articular fibrous bands, hypertrophic synovitis and peri-patellar adhesions. A total of eight patients suffered from an anterior cyclops lesion and six patients showed pseudomenicus. In 19 cases a medial and lateral relapse of the patella was performed; only 5 patients got an isolated lateral release. The mean knee flexion was 119 degrees (100-130) at the end of arthroscopy and was 97 degrees (75-115) at the last follow up. The eight patients with extension lags decreased from 27 degrees (10 degrees-35 degrees) pre-operatively to 4 degrees (0-10) at time of follow up. The average knee society ratings increased from 70

Atraumatic haemarthrosis following total knee replacement treated with selective embolisation.

PubMed

Karataglis, Dimitrios; Marlow, Duncan; Learmonth, Duncan J A

2006-06-01

Spontaneous haemarthrosis in the absence of anticoagulant medication or a bleeding disorder is a very rare complication after total knee arthroplasty. A case of recurrent spontaneous haemarthrosis following total knee replacement in a 69-year-old patient is reported. Angiography was used to aid the diagnosis. It demonstrated an abnormal blush of vessels around the anterior aspect of the knee joint, that was fed by genicular branches and a recurrent branch of the anterior tibial artery. Selective embolisation of the bleeding vessels with coils led to immediate control of the bleeding. No further recurrence of haemarthrosis has been recorded.

Treatment of deep infection of total knee arthroplasty using a two-stage procedure.

PubMed

Pietsch, Martin; Hofmann, Siegfried; Wenisch, Christian

2006-03-01

Treatment of deep infection of total knee arthroplasty by two-stage reimplantation. Using an articulating spacer may reduce the disadvantages of a static spacer (ligament contracture, muscle atrophy, muscle contraction, arthrofibrosis, and bone loss). Restoration of pain-free loading and ability to walk. Late deep infection after total knee arthroplasty. infection occurring at least 6 weeks after the initial arthroplasty. Large metaphyseal bony defects of the distal femur and proximal tibia. Missing or insufficient extensor mechanism. The articulating spacer is made intraoperatively by cleaning and autoclaving the explanted femoral component and the tibial polyethylene insert. These components are reinserted by "press-fit cementing" without cement interdigitation into the trabecular bone. The cement is loaded with antibiotic during the same operation (2-4 g antibiotics per 40 g of cement powder). With the articulating spacer in place, partial weight bearing with crutches and continuous passive motion daily up to a flexion of 90 degrees are allowed. Usually, reimplantation with a standard revision system is scheduled for 6-12 weeks after spacer implantation. In a prospective study 33 consecutive patients were treated from February 2000 to July 2003. The average period of hospitalization after spacer implantation was 14 days (8-26 days). Three patients had recurrent infection (success rate 91%) after a mean follow-up period of 28 months (12-48 months). The average Hospital for Special Surgery Knee Score could be increased from 67 points (44-84 points) preoperatively to 87 points (53-97 points) after reimplantation. The complications were one temporary peroneal palsy, one dislocation of the spacer due to the absence of the extensor ligaments, and one fracture of the tibia due to substantial primary metaphyseal bone loss.

Radiographic and scintigraphic evaluation of total knee arthroplasty

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

Schneider, R.; Soudry, M.

1986-04-01

Various radiographic and scintigraphic methods are used to supplement clinical findings in the evaluation of total knee arthroplasty and its complications. Serial roentgenograms offer reliable information for diagnosing mechanical loosening. Wide and extensive radiolucency at the cement-bone interface and shift in position and alignment of prosthetic components can be seen in almost all cases by the time revision is necessary. Radiographic abnormalities are usually not present in acute infection, but are often present in chronic infection. Bone scanning has a high sensitivity for diagnosis of infection or loosening, but is nonspecific because increased uptake is often present around asymptomatic totalmore » knee arthroplasties with normal radiographs. Differential bone and Gallium scanning and scanning with Indium 111-labeled leukocytes have a greater specificity for diagnosis of infection than does bone or Gallium scanning alone. Routine radiographic and scintigraphic studies have shown a high incidence of deep vein thrombosis in the calf after total knee arthroplasty. Clinically significant pulmonary embolization is infrequent.« less

[Interest of non invasive navigation in total knee arthroplasty].

PubMed

Zorman, D; Leclercq, G; Cabanas, J Juanos; Jennart, H

2015-01-01

During surgery of total knee arthroplasty, we use a computerized non invasive navigation (Brainlab Victor Vision CT-free) to assess the accuracy of the bone cuts (navigation expresse). The purpose of this study is to evaluate non invasive navigation when a total knee arthroplasty is achieved by conventional instrumentation. The study is based on forty total knee arthroplasties. The accuracy of the tibial and distal femoral bone cuts, checked by non invasive navigation, is evaluated prospectively. In our clinical series, we have obtained, with the conventional instrumentation, a correction of the mechanical axis only in 90 % of cases (N = 36). With non invasive navigation, we improved the positioning of implants and obtained in all cases the desired axiometry in the frontal plane. Although operative time is increased by about 15 minutes, the non invasive navigation does not induce intraoperative or immediate postoperative complications. Despite the cost of this technology, we believe that the reliability of the procedure is enhanced by a simple and reproducible technique.

The Impact of Mechanical and Restricted Kinematic Alignment on Knee Anatomy in Total Knee Arthroplasty.

PubMed

Almaawi, Abdulaziz M; Hutt, Jonathan R B; Masse, Vincent; Lavigne, Martin; Vendittoli, Pascal-Andre

2017-07-01

Total knee arthroplasty (TKA), aiming at neutral mechanical alignment (MA), inevitably modifies the patient's native knee anatomy. Another option is kinematic alignment (KA), which aims to restore the original anatomy of the knee. The aim of this study was to evaluate the variations in lower limb anatomy of a patient population scheduled for TKA, and to assess the use of a restricted KA TKA protocol and compare the resulting anatomic modifications with the standard MA technique. A total of 4884 knee computed tomography scans were analyzed from a database of patients undergoing TKA with patient-specific instrumentation. The lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and hip-knee-ankle angle (HKA) were measured. Bone resections were compared using a standard MA and a restricted KA aiming for independent tibial and femoral cuts of maximum ±5° deviation from the coronal mechanical axis and a resulting overall coronal HKA within ±3° of neutral. The mean preoperative MPTA was 2.9° varus, LDFA was 2.7° valgus, and overall HKA was 0.1° varus. Using our protocol, 2475 knees (51%) could have undergone KA without adjustment. To include 4062 cases (83%), mean corrections of 0.5° for MPTA and 0.3° for LDFA were needed, significantly less than with MA (3.3° for MPTA and 3.2° for LDFA; P < .001). The range of knee anatomy in patients scheduled for TKA is wide. MA leads to greater modifications of knee joint anatomy. To avoid reproducing extreme anatomy, the proposed restricted KA protocol provides an interesting hybrid option between MA and true KA. Copyright © 2017 Elsevier Inc. All rights reserved.

Total Knee Arthroplasty for Knee Osteoarthritis: Support for a Foregone Conclusion?

PubMed

Steinhaus, Michael E; Christ, Alexander B; Cross, Michael B

2017-07-01

Total knee arthroplasty (TKA) is generally accepted as the definitive treatment for advanced knee arthritis after patients fail nonoperative treatments; however, the safety and efficacy of TKA compared to continued nonoperative treatment has never been proven in high-quality, randomized controlled trials. Recently, a 2015 Danish study published a 12-month follow-up on a cohort of patients randomized to either a TKA or continued nonsurgical management for advanced knee osteoarthritis (OA). The authors reported significantly greater improvement in the TKA group in functional outcome scores such as the overall Knee Injury and Osteoarthritis Outcome Score (KOOS 4 score), the KOOS subscales, EQ-5D descriptive index, and timed get up-and-go and 20-m walk tests; however, patients in the TKA did suffer significantly more serious adverse events (SAE). The authors concluded that TKA combined with additional nonoperative care postoperatively is more efficacious than nonsurgical treatment alone in terms of improving pain, function, and quality of life at 12 months but is associated with more SAE. The purpose of this review is to identify the strengths and weaknesses of this trial, interpret its outcomes within the context of prior literature, and evaluate the validity of its conclusions.

No Differences Identified in Transverse Plane Biomechanics Between Medial Pivot and Rotating Platform Total Knee Implant Designs.

PubMed

Papagiannis, Georgios I; Roumpelakis, Ilias M; Triantafyllou, Athanasios I; Makris, Ioannis N; Babis, George C

2016-08-01

Total knee arthroplasties (TKAs) using well-designed, fixed bearing prostheses, such as medial pivot (MP), have produced good long-term results. Rotating-platform, posterior-stabilized (RP-PS) mobile bearing implants were designed to decrease polyethylene wear. Sagittal and coronal plane TKA biomechanics are well examined and correlated to polyethylene wear. However, limited research findings describe this relationship in transverse plane. We assumed that although axial plane biomechanics might not be the most destructive parameters on polyethylene wear, it is important to clarify their role because both joint kinematics and kinetics in all 3 planes are important input parameters for TKA wear testing (International Organization for Standardization 14243-1 and 14343-3). Our hypothesis was that transverse plane overall range of motion (ROM) and/or peak moment show differences that reflect on wear advantages when compared RP-PS implants to MP designs. Two groups (MPs = 24 and RP-PSs = 22 subjects) were examined by using 3D gait analysis. The variables were total internal-external rotation (IER) ROM and peak IER moments. No statistically significant difference was demonstrated between the 2 groups in kinetics (P = .389) or kinematics (P = .275). In the present study, no wear advantages were found between 2 TKAs. Both designs showed identical kinetics at the transverse plane in level-ground walking. Kinematic analysis could not illustrate any statistically significant difference in terms of overall IER ROM. Nevertheless, kinematic gait pattern differences observed possibly reflect different patterns of joint surface motion or abnormal gait patterns. Thus, wear testing with various input waveforms combined with functional data analysis will be necessary to identify the actual effects of gait variability on polyethylene wear. Copyright © 2016 Elsevier Inc. All rights reserved.

Total knee arthroplasty in patients with a prior fracture of the tibial plateau.

PubMed

Weiss, Nicholas G; Parvizi, Javad; Trousdale, Robert T; Bryce, Rex D; Lewallen, David G

2003-02-01

A fracture of the tibial plateau may predispose the knee to the development of posttraumatic arthritis. Malunion, intra-articular chondro-osseous defects, limb malalignment, retained internal fixation devices, and poor surrounding soft tissues may in turn compromise the outcome of total knee arthroplasty. The aim of our study was to evaluate the results of total knee arthroplasty in patients with a previous fracture of the tibial plateau. The results of sixty-two condylar total knee arthroplasties performed with cement, from 1988 to 1999, in sixty-two patients with a previous fracture of the tibial plateau were reviewed. The fracture of the tibial plateau had been treated by open reduction and internal fixation in thirty-eight knees, external fixation in one knee, and nonoperatively in twenty-three knees. There were forty women and twenty-two men with an average age of sixty-three years at the time of the arthroplasty. Knee Society scores were recorded preoperatively and at the time of follow-up, at an average of 4.7 years, and complications were noted. No patient was lost to follow-up. The mean Knee Society scores improved significantly (p < 0.0001), from 43.9 points for pain and 52 points for function preoperatively to 82.9 and 84 points, respectively, at the time of the latest follow-up. There were thirteen reoperations, which included manipulation with the patient under anesthesia (five knees), wound revision (three knees), and component revision (five knees). There were six intraoperative complications (10%). A postoperative complication occurred in sixteen knees (26%). The vast majority of patients treated with total knee arthroplasty after a previous fracture of the tibial plateau have substantial improvement in function and relief of pain. However, these patients are at increased risk for perioperative complications, as evidenced by the high reoperation rate of 21% in this study.

Astym® Therapy for the Management of Recalcitrant Knee Joint Stiffness after Total Knee Arthroplasty.

PubMed

Bhave, Anil; Corcoran, James; Cherian, Jeffery J; Mont, Michael A

2016-01-01

Knee stiffness is a common complication after total knee arthroplasty (TKA). Despite studies published on the surgical management of reduced range of motion (ROM) after TKA, there is limited evidence on the nonoperative management of joint and soft tissue imbalances possibly contributing to reduced knee ROM. This report assesses changes in ROM, pain, function, and patellar tendon length after Astym® joint mobilization use. A 38-year-old male professional skier had a right TKA 3 months before presentation with 2 subsequent manipulations under anesthesia secondary to persistent knee stiffness. He had patellar baja on radiograph, a reduced arc of ROM, reduced patellar mobility and muscular extensibility, and pain to palpation along the patellar tendon. He had 12 visits of physical therapy with the use of Astym®, patellar mobilization, and tibio-femoral mobilizations with movement. The patient also used a customized knee device at home for prolonged knee extension stretching. The patient was treated for 12 visits, along with home use of customized bracing for knee extension. Significant improvements were seen in pain, function, and ROM. He returned to work full-time, ambulated prolonged distances, and negotiated stairs pain-free. He also demonstrated resolution of patellar baja radiographically. Conservative management of recalcitrant knee joint stiffness after primary TKA can be effective in restoring knee mobility and reducing pain and activity limitation. A multimodal approach using Astym® treatment, customized knee bracing, and targeted joint mobilization can be effective in resolving knee joint stiffness.

Intraoperative evaluation of total knee replacement: kinematic assessment with a navigation system.

PubMed

Casino, Daniela; Zaffagnini, Stefano; Martelli, Sandra; Lopomo, Nicola; Bignozzi, Simone; Iacono, Francesco; Russo, Alessandro; Marcacci, Maurilio

2009-04-01

Interest in the kinematics of reconstructed knees has increased since it was shown that the alteration of knee motion could lead to abnormal wear and damage to soft tissues. We performed intraoperative kinematic measurements using a navigation system to study knee kinematics before and after posterior substituting rotating platform total knee arthroplasty (TKA). We verified intraoperatively (1) if varus/valgus (VV) laxity and anterior/posterior (AP) laxity were restored after TKA; (2) if TKA induced abnormal femoral rollback; and (3) how tibial axial rotation was influenced by TKA throughout the range of flexion. We found that TKA improved alignment in preoperative osteoarthritic varus knees which became neutral after surgery and maintained a neutral alignment in neutral knees. The VV stability at 0 degrees was restored while AP laxity at 90 degrees significantly increased after TKA. Following TKA, the femur had an abnormal anterior translation up to 60 degrees of flexion, followed by a small rollback of 12 +/- 5 mm. TKA influenced the tibia rotation pattern during flexion, but not the total amount of internal/external rotation throughout whole range of flexion, which was preserved after TKA (6 degrees +/- 5 degrees ). This study showed that the protocol proposed might be useful to adjust knee stability at time zero and that knee kinematic outcome during total knee replacement can be monitored by a navigation system.

The trivector approach for minimally invasive total knee arthroplasty: a technical note.

PubMed

Benazzo, Francesco; Rossi, Stefano Marco Paolo

2012-09-01

One of the main criticisms of minimally invasive approaches in total knee arthroplasty has been their poor adaptability in cases of major deformity or stiffness of the knee joint. When they are used in such cases, excessive soft-tissue tension is needed to provide appropriate joint exposure. Here, we describe the "mini trivector approach," which has become our standard approach for total knee replacement because it permits us to enlarge the indication for minimally or less invasive total knee replacement to many knees where quad sparing, a subvastus approach, or a mini quad or mini midvastus snip may not be sufficient to achieve correct exposure. It consists of a limited double snip of the VMO and the quadriceps tendon that reduces tension on the extensor mechanism and allows easier verticalization of the patella as well as good joint exposure.

The Influence Of Component Alignment On The Life Of Total Knee Prostheses

NASA Astrophysics Data System (ADS)

Bugariu, Delia; Bereteu, Liviu

2012-12-01

An arthritic knee affects the patient's life by causing pain and limiting movement. If the cartilage and the bone surfaces are severely affected, the natural joint is replaced with an artificial joint. The procedure is called total knee arthroplasty (TKA). Lately, the numbers of implanted total knee prostheses grow steadily. An important factor in TKA is the perfect alignment of the total knee prosthesis (TKP) components. Component misalignment can lead to the prosthesis loss by producing wear particles. The paper proposes a study on mechanical behaviors of a TKP based on numerical analysis, using ANSYS software. The numerical analysis is based on both the normal and the changed angle of the components alignment.

Extra-articular deformity correction using Taylor spatial frame prior to total knee arthroplasty.

PubMed

Tawari, Gautam J K; Maheshwari, Rajan; Madan, Sanjeev S

2018-03-20

A good long-term outcome following a total knee arthroplasty relies on restoration of the mechanical axis and effective soft tissue balancing of the prosthetic knee. Arthroplasty surgery in patients with secondary osteoarthritis of the knee with an extra-articular tibial deformity is a complex and challenging procedure. The correction of mal-alignment of the mechanical axis is associated with unpredictable result and with higher revision rates. Single-staged deformity correction and replacement surgery often result in the use of constraint implants. We describe our experience with staged correction of deformity using a Taylor Spatial Frame (TSF) followed by total knee arthroplasty in these patients and highlight the advantage of staged approach. The use of TSF fixator for deformity correction prior to a primary total knee arthroplasty has not been described in the literature. We describe three cases of secondary osteoarthritis of the knee associated with multiplanar tibial deformity treated effectively with a total knee arthroplasty following deformity correction and union using a TSF. All patients had an improved Knee Society score and Oxford Knee score postoperatively and were satisfied with their replacement outcome. Staged deformity correction followed by arthroplasty allows the use of standard primary arthroplasty implants with predicable results and flexible aftercare. This approach may also provide significant improvement of patient symptoms following correction of deformity resulting in deferment of the arthroplasty surgery.

Late dislocation of rotating platform in New Jersey Low-Contact Stress knee prosthesis.

PubMed

Huang, Chun-Hsiung; Ma, Hon-Ming; Liau, Jiann-Jong; Ho, Fang-Yuan; Cheng, Cheng-Kung

2002-12-01

Five patients with late rotational dislocation of the rotating platform bearing in the New Jersey Low-Contact Stress total knee arthroplasty are reported. The prostheses had functioned well for 8 to 12 years before failure. Preoperative radiographs showed asymmetric femorotibial joint spaces. Entrapment of the dislocated bearing in three patients and spontaneous reduction of the dislocated bearing in another two patients were seen at revision. Femorotibial ligamentous instability was found after reduction. The retrieved polyethylene bearings showed advanced wear and cold flow deformities and the thickness was reduced. The revision arthroplasty was accomplished by replacement with a thicker bearing element. Progressive femorotibial ligament laxity and reduction of the thickness of polyethylene with wearing break down the originally well-balanced soft tissue tension of the knee. The rotational degree of the rotating platform bearing is unrestricted, which may result in late dislocation. Polyethylene wear is unavoidable in knee prostheses using metal contact with polyethylene even with a mobile-bearing design. Efforts to reduce polyethylene wear are mandatory.

Gait Parameters and Functional Outcomes After Total Knee Arthroplasty Using Persona Knee System With Cruciate Retaining and Ultracongruent Knee Inserts.

PubMed

Rajgopal, Ashok; Aggarwal, Kalpana; Khurana, Anshika; Rao, Arun; Vasdev, Attique; Pandit, Hemant

2017-01-01

Total knee arthroplasty is a well-established treatment for managing end-stage symptomatic knee osteoarthritis. Currently, different designs of prostheses are available with majority ensuring similar clinical outcomes. Altered surface geometry is introduced to strive toward gaining superior outcomes. We aimed to investigate any differences in functional outcomes between 2 different polyethylene designs namely the Persona CR (cruciate retaining) and Persona UC (ultracongruent) tibial inserts (Zimmer-Biomet, Warsaw, IN). This prospective single blind, single-surgeon randomized controlled trial reports on 105 patients, (66 female and 39 male), who underwent simultaneous bilateral total knee arthroplasty using the Persona knee system (Zimmer-Biomet) UC inserts in one side and CR inserts in the contralateral side. By a blind assessor, at regular time intervals patients were assessed in terms of function and gait. The functional knee scoring scales used were the Western Ontario and McMaster Universities Osteoarthritis Index and Modified Knee Society Score. The gait parameters evaluated were foot pressure and step length. During the study period, no patient was lost to follow-up or underwent revision surgery for any cause. Western Ontario and McMaster Universities Osteoarthritis Index scores, Modified Knee Society Score, and knee range of motion of all 105 patients assessed preoperatively and postoperatively at 6 months, 1 year, and 2 years showed statistically better results (P < .05) for UC inserts. Gait analysis measuring foot pressures and step length, however, did not show any statistically significant differences at 2-year follow-up. Ultracongruent tibial inserts show significantly better functional outcomes as compared to CR inserts during a 2-year follow-up period. However, in this study these findings were not shown to be attributed to differences in gait parameters. Copyright © 2016 Elsevier Inc. All rights reserved.

Knee arthrodesis with the Vari-Wall nail for treatment of infected total knee arthroplasty.

PubMed

Garcia-Lopez, Ignacio; Aguayo, Miguel Anguel; Cuevas, Antonio; Navarro, Pablo; Prieto, Cristobal; Carpintero, Pedro

2008-12-01

We reviewed 20 patients who had undergone one-stage (7 cases) or two-stage (13 cases) knee arthrodesis using the Vari-Wall intramedullary nail, as a salvage operation following infection of a total knee arthroplasty. The procedure was followed by systemic antibiotic administration and early rehabilitation. Intraoperative microbiological cultures were taken. The average period of follow-up was 20 months. Solid union was achieved in 80%; mean time to fusion was 9 months. There was no recurrence of infection. The average limb length discrepancy was 2.45 cm. A walking aid was needed by 95% of the patients. The complication rate was 30% including 4 pseudarthroses, one intraoperative fracture and one peroneal nerve palsy. The Vari-Wall intramedullary nail is a good option when an arthrodesis is indicated for salvage of an infected total knee arthroplasty. It can be performed in one or two stages depending on several factors such as microbiologic culture results. It achieved good pain relief and acceptable functional results in this study.

Best multimodal analgesic protocol for total knee arthroplasty.

PubMed

Webb, Christopher A J; Mariano, Edward R

2015-01-01

Total knee arthroplasty is one of the most commonly performed operations in the USA. As with any elective joint surgery, the primary goal includes functional restoration that is not limited by pain. The use of peripheral nerve blocks for patients undergoing knee arthroplasty has resulted in decreased pain scores, improved early ambulation and decreased time to achieve hospital discharge criteria. Concern has been raised over the potential risks of femoral nerve block, and there has been growing support for the adductor canal block. It is the author's opinion that when not contraindicated, intraoperative neuraxial anesthesia combined with a continuous adductor canal block and a multimodal medication regimen for postoperative pain control is the best analgesic protocol for knee arthroplasty.

Continuous passive motion and its effects on knee flexion after total knee arthroplasty in patients with knee osteoarthritis.

PubMed

Liao, Chun-De; Huang, Yi-Ching; Lin, Li-Fong; Chiu, Yen-Shuo; Tsai, Jui-Chen; Chen, Chun-Lung; Liou, Tsan-Hon

2016-08-01

This study evaluated the effects of continuous passive motion (CPM) on accelerated flexion after total knee arthroplasty (TKA) and whether CPM application measures (i.e. initial angle and daily increment) are associated with functional outcomes. A retrospective investigation was conducted at the rehabilitation centre of a university-based teaching hospital. Patients who received CPM therapy immediately after TKA surgery were categorized into rapid-, normal-, and slow-progress groups according to their response to CPM during their acute inpatient stay. Knee pain, passive knee flexion, and knee function-measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)-were assessed preoperatively at discharge and at 3- and 6-month outpatient follow-up visits. A total of 354 patients were followed for 6 months after inpatient-stay discharge. The patients in the rapid-progress group (n = 119) exhibited significantly greater knee flexions than those in the slow-progress group did (n = 103) at the 3-month follow-up [mean difference (MD) = 10.3°, 95 % confidence interval (CI) 4.3°-16.3°, p < 0.001] and 6-month follow-up (MD = 10.9°, 95 % CI 6.3°-15.6°, p < 0.001). Significant WOMAC score differences between the rapid- and slow-progress groups were observed at the 3-month follow-up (MD = 7.2, 95 % CI 5.4-9.1, p < 0.001) and 6-month follow-up (MD = 16.1, 95 % CI 13.4-18.7, p < 0.001). CPM initial angles and rapid progress significantly predicted short- and long-term outcomes in knee flexion and WOMAC scores (p < 0.001). When CPM is used, early application with initial high flexion and rapid progress benefits knee function up to 6 months after TKA. II.

Metal-backed versus all-polyethylene tibial components in primary total knee arthroplasty

PubMed Central

2011-01-01

Background and purpose The choice of either all-polyethylene (AP) tibial components or metal-backed (MB) tibial components in total knee arthroplasty (TKA) remains controversial. We therefore performed a meta-analysis and systematic review of randomized controlled trials that have evaluated MB and AP tibial components in primary TKA. Methods The search strategy included a computerized literature search (Medline, EMBASE, Scopus, and the Cochrane Central Register of Controlled Trials) and a manual search of major orthopedic journals. A meta-analysis and systematic review of randomized or quasi-randomized trials that compared the performance of tibial components in primary TKA was performed using a fixed or random effects model. We assessed the methodological quality of studies using Detsky quality scale. Results 9 randomized controlled trials (RCTs) published between 2000 and 2009 met the inclusion quality standards for the systematic review. The mean standardized Detsky score was 14 (SD 3). We found that the frequency of radiolucent lines in the MB group was significantly higher than that in the AP group. There were no statistically significant differences between the MB and AP tibial components regarding component positioning, knee score, knee range of motion, quality of life, and postoperative complications. Interpretation Based on evidence obtained from this study, the AP tibial component was comparable with or better than the MB tibial component in TKA. However, high-quality RCTs are required to validate the results. PMID:21895503

Knee Brace Would Lock And Unlock Automatically

NASA Technical Reports Server (NTRS)

Myers, Neill; Forbes, John; Shadoan, Mike; Baker, Kevin

1995-01-01

Proposed knee brace designed to aid rehabilitation of person who suffered some muscle damage in leg. Not limited to locking in straight-leg position and, instead, locks at any bend angle. Does not prevent knee from bearing weight. Instead, knee brace allows knee to bear weight and locks only when foot and lower leg bear weight. Thus, brace prevents flexion that wearer desired to prevent but could not prevent because of weakened muscles. Knee bends freely to exercise knee-related muscles. Knee brace strapped at upper end to leg above knee, and anchored at lower end by stirrup under foot. Joint mechanism (identical mechanisms used in left and right assemblies) allows knee joint to flex freely except when weight applied to heel.

A comprehensive combined experimental and computational framework for pre-clinical wear simulation of total knee replacements.

PubMed

Abdelgaied, A; Fisher, J; Jennings, L M

2018-02-01

A more robust pre-clinical wear simulation framework is required in order to simulate wider and higher ranges of activities, observed in different patient populations such as younger more active patients. Such a framework will help to understand and address the reported higher failure rates for younger and more active patients (National_Joint_Registry, 2016). The current study has developed and validated a comprehensive combined experimental and computational framework for pre-clinical wear simulation of total knee replacements (TKR). The input mechanical (elastic modulus and Poisson's ratio) and wear parameters of the moderately cross-linked ultra-high molecular weight polyethylene (UHMWPE) bearing material were independently measured from experimental studies under realistic test conditions, similar to the loading conditions found in the total knee replacements. The wear predictions from the computational wear simulation were validated against the direct experimental wear measurements for size 3 Sigma curved total knee replacements (DePuy, UK) in an independent experimental wear simulation study under three different daily activities; walking, deep squat, and stairs ascending kinematic conditions. The measured compressive mechanical properties of the moderately cross-linked UHMWPE material were more than 20% lower than that reported in the literature under tensile test conditions. The pin-on-plate wear coefficient of moderately cross-linked UHMWPE was significantly dependant of the contact stress and the degree of cross-shear at the articulating surfaces. The computational wear predictions for the TKR from the current framework were consistent and in a good agreement with the independent full TKR experimental wear simulation measurements, with 0.94 coefficient of determination of the framework. In addition, the comprehensive combined experimental and computational framework was able to explain the complex experimental wear trends from the three different daily

Knee Fusion or Above-The-Knee Amputation after Failed Two-Stage Reimplantation Total Knee Arthroplasty

PubMed Central

Rodriguez-Merchan, E. Carlos

2015-01-01

Prosthetic joint infection (PJI) is a serious complication of total knee arthroplasty (TKA). Control of infection after a failed two-stage TKA is not always possible, and the resolution of infection may require an above-knee amputation (AKA) or a the-knee (KF). The purpose of this review is to determine which treatment method (AKA or KF) yields better function and ambulatory status for patients after a failed two-stage reimplantation. A PubMed search related to the resolution of infection by means of an above-the-knee amputation (AKA) or a knee fusion was performed until 10 January 2015. The key words were: infected TKA and above-the-knee amputation. Five hundred and sixty-six papers were found, of which ten were reviewed because they were focused on the topic of the article. KF should be strongly considered as the treatment of choice for patients who have persistent infected TKA after a failed two-stage revision arthroplasty. Patients can walk at least inside the house, and activity of daily living independence is achieved by the patients with successful KF, although walking aids, including a shoe lift, are required. An intramedullary nail leads to better functional results than an external fixator. The functional outcome after AKA performed after TKA is poor. A substantial percentage of the patients never fit with a prosthesis, and those who are seldom obtain functional independence. Only 50% of patients are able to walk after AKA. Patients receiving KF for treating recurrent PJI after TKA have better function and ambulatory status compared to patients receiving AKA. KF must be recommended as the treatment of choice for patients who have persistent infected TKA after a failed two-stage reimplantation procedure. PMID:26550586

Knee Fusion or Above-The-Knee Amputation after Failed Two-Stage Reimplantation Total Knee Arthroplasty.

PubMed

Rodriguez-Merchan, E Carlos

2015-10-01

Prosthetic joint infection (PJI) is a serious complication of total knee arthroplasty (TKA). Control of infection after a failed two-stage TKA is not always possible, and the resolution of infection may require an above-knee amputation (AKA) or a the-knee (KF). The purpose of this review is to determine which treatment method (AKA or KF) yields better function and ambulatory status for patients after a failed two-stage reimplantation. A PubMed search related to the resolution of infection by means of an above-the-knee amputation (AKA) or a knee fusion was performed until 10 January 2015. The key words were: infected TKA and above-the-knee amputation. Five hundred and sixty-six papers were found, of which ten were reviewed because they were focused on the topic of the article. KF should be strongly considered as the treatment of choice for patients who have persistent infected TKA after a failed two-stage revision arthroplasty. Patients can walk at least inside the house, and activity of daily living independence is achieved by the patients with successful KF, although walking aids, including a shoe lift, are required. An intramedullary nail leads to better functional results than an external fixator. The functional outcome after AKA performed after TKA is poor. A substantial percentage of the patients never fit with a prosthesis, and those who are seldom obtain functional independence. Only 50% of patients are able to walk after AKA. Patients receiving KF for treating recurrent PJI after TKA have better function and ambulatory status compared to patients receiving AKA. KF must be recommended as the treatment of choice for patients who have persistent infected TKA after a failed two-stage reimplantation procedure.

Transcutaneous electrical nerve stimulation for postoperative pain control after total knee arthroplasty

PubMed Central

Li, Jifeng; Song, Yuze

2017-01-01

Abstract Background: This meta-analysis aimed to evaluate the efficiency and safety of transcutaneous electrical nerve stimulation (TENS) for pain control after total knee arthroplasty. Methods: A systematic search was performed in Medline (1966 to June 2017), PubMed (1966 to June 2017), Embase (1980 to June 2017), ScienceDirect (1985 to June 2017), and the Cochrane Library. Only randomized controlled trial (RCT) was included. The fixed/random effect model was used according to the heterogeneity tested by I2 statistic. Meta-analysis was performed using Stata 11.0 software. Results: Five RCTs including 472 patients met the inclusion criteria. The present meta-analysis indicated that there were significant differences between groups in terms of visual analogue scale score at 12 hours (average: 3.58 vs 4.34, SMD = −0.260, 95% CI: −0.442 to −0.078, P = .005), 24 hours (average: 3.18 vs 3.52, SMD = −0.244, 95% CI: −0.426 to −0.063, P = .008), and 48 hours (average: 2.70 vs 2.96, SMD = −0.214, 95% CI: −0.395 to −0.033, P = .021) after total knee arthroplasty. Significant differences were found regarding opioid consumption at 12 hours (average: 14.44 vs 18.54, SMD = −0.503, 95% CI: −0.687 to −0.319, P = .000), 24 hours (average: 16.10 vs 18.40, SMD = −0.262, 95% CI: −0.443 to −0.080, P = .005), and 48 hours (average: 12.92 vs 15.12, SMD = −0.183, 95% CI: −0.364 to −0.002, P = .048). Conclusion: TENS could significantly reduce pain and opioid consumption after total knee arthroplasty. In addition, there were fewer adverse effects in the TENS groups. Higher quality RCTs are required for further research. PMID:28906393

Profix cemented total knee replacement: a 5-year outcome review from Lagos, Nigeria.

PubMed

Ugbeye, M E; Odunubi, O O; Dim, E M; Ekundayo, O O

2012-01-01

Total knee replacement is a standard treatment for severe osteoarthritis of the knees. It is however, still a novel procedure in Nigeria. Literature on the procedure and outcome of management are sparse in Nigeria. This study aimed at describing Total Knee prosthetic Replacement as it is practiced in National Orthopaedic Hospital, Lagos. Data on patients treated with Total knee replacement between 2006 and 2010 were analyzed retrospectively. The standard anterior approach, with a medial parapatellar incision under pneumatic tourniquet was used in all cases. There were a total of 59 knees in 48 patients operated, with a female: male ratio of 5:1. Patients were in the sixth to ninth decades of life. There was a statistically significant relationship between duration of symptoms and severity of angular deformity. The average pre-operative Knee score (KS) was 27 and average function score (FS) was 43. Average duration of surgery was 126.38 minutes. Tourniquet removal after wound closure was associated with reduced intra-operative blood loss (p < 0.05). Post-operative complications included peri-prosthetic fracture (1.69%), post-operative anaemia (8.47%), superficial wound dehiscence (3.39%) and foot drop (3.39%). The mean post-operative KS and FS increased to 80 and 75 respectively. Total knee replacement, though a novel procedure in our institution is beneficial to patients with severe osteoarthritis. A long term outcome study is being planned.

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

PubMed

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

2013-01-01

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

[EFFECTIVENESS OF BILATERAL TOTAL HIP AND KNEE ARTHROPLASTY FOR SEVERE INFLAMMATORY ARTHROPATHIES].

PubMed

Li, Xin; Li, Heng; Ni, Ming; Li, Xiang; Song, Xinggui; Kong, Xiangpeng; Li, Yucong; Chen, Jiying

2016-11-08

To evaluate the application and effectiveness of bilateral total hip arthroplasty and total knee arthroplasty in the treatment of severe inflammatory arthropathies. Between September 2008 and September 2015, 31 patients with severe inflammatory arthropathies were treated with bilateral total hip arthroplasty and total knee arthroplasty. Of 31 cases, 22 were male and 9 were female with an average age of 30 years (range, 20 to 41 years); there were 15 cases of rheumatoid arthritis and 16 cases of ankylosing spondylitis with an average onset age of 14 years (range, 5-28 years); all 4 ankylosed joints were observed in 11 cases, 3 ankylosed joints in 2 cases, 2 ankylosed joints in 6 cases, 1 ankylosed joint in 1 case, and no ankylosed joint in 11 cases. Before operation, the hip range of motion (ROM) value was (17.82±28.18)°, and the knee ROM value score was (26.45±30.18)°; the hip Harris score was 29.64±11.58, and the hospital for special surgery (HSS) score was 27.07±11.04. The patients were grouped and compared in accordance with etiology and ankylosed joint. One-stage arthroplasty was performed in 1 case, two-stage arthroplasty in 22 cases, three-stage arthroplasty in 7 cases, and four-stage arthroplasty in 1 case. The total operation time was 325-776 minutes; the total blood loss was 900-3 900 mL; the total transfusion volume was 2 220-8 070 mL; and the total hospitalization time was 21-65 days. The patients were followed up 12-94 months (mean, 51 months). The hip and knee ROM values, Harris score and HSS score at last follow-up were significantly improved when compared with preoperative ones ( P <0.05). The subjective satisfaction degree was good in 16 cases, moderate in 10 cases, and poor in 5 cases. Periprosthetic infection occurred in 2 cases (3 knees), joint stiffness in 3 cases (6 knees), joint instability in 1 case (1 knee), leg length discrepancy of >2 cm in 2 cases, and flexion deformity of 10° in 1 case (1 knee). The hip and knee ROM values, Harris

Primary Total Knee Replacement: Is Suction a Portal of Infection?

PubMed Central

Budnar, Vijaya M; Amirfeyz, Rouin; Ng, Michael; Bannister, Gordon C; Blom, Ashley W

2009-01-01

INTRODUCTION Pulsed lavage during a total knee replacement usually leaves a pool of fluid on the surgical drapes. It is common practice to suck away this fluid using the same suction device used intra-operatively. This could be a cause of direct wound contamination. We hypothesised that bacteria contaminate fluid that collects around the foot in total knee replacement surgery and that suction equipment could be a portal of contamination. We also hypothesised that bacterial count in the fluid is lower if chlorhexidine, rather than saline, is used in the pulsed lavage. PATIENTS AND METHODS Forty patients undergoing primary total knee replacement were divided into two groups. The first group had pulsed lavage with normal saline and the second with 0.05% chlorhexidine. RESULTS At the end of the operation, 20 ml of fluid, pooled on the surgical drapes was aspirated and cultured for bacterial growth. None of the fluid samples showed bacterial growth. CONCLUSIONS Suction device used peri-operatively during knee replacement is unlikely to be a cause of wound contamination. Pulsed lavage with normal saline is as effective as lavage with chlorhexidine. PMID:19335972

Postoperative Knee Flexion Angle Is Affected by Lateral Laxity in Cruciate-Retaining Total Knee Arthroplasty.

PubMed

Nakano, Naoki; Matsumoto, Tomoyuki; Muratsu, Hirotsugu; Takayama, Koji; Kuroda, Ryosuke; Kurosaka, Masahiro

2016-02-01

Although many studies have reported that postoperative knee flexion is influenced by preoperative conditions, the factors which affect postoperative knee flexion have not been fully elucidated. We tried to investigate the influence of intraoperative soft tissue balance on postoperative knee flexion angle after cruciate-retaining (CR) total knee arthroplasty (TKA) using a navigation and an offset-type tensor. We retrospectively analyzed 55 patients with osteoarthritis who underwent TKA using e.motion-CR (B. Braun Aesculap, Germany) whose knee flexion angle could be measured at 2 years after operation. The exclusion criteria included valgus deformity, severe bony defect, infection, and bilateral TKA. Intraoperative varus ligament balance and joint component gap were measured with the navigation (Orthopilot 4.2; B. Braun Aesculap) while applying 40-lb joint distraction force at 0° to 120° of knee flexion using an offset-type tensor. Correlations between the soft tissue parameters and postoperative knee flexion angle were analyzed using simple linear regression models. Varus ligament balance at 90° of flexion (R = 0.56; P < .001) and lateral compartment gap at 90° of flexion (R = 0.51; P < .001) were positively correlated with postoperative knee flexion angle. In addition, as with past studies, joint component gap at 90° of flexion (R = 0.30; P < .05) and preoperative knee flexion angle (R = 0.63; P < .001) were correlated with postoperative knee flexion angle. Lateral laxity as well as joint component gap at 90° of flexion is one of the most important factors affecting postoperative knee flexion angle in CR-TKA. Copyright © 2016 Elsevier Inc. All rights reserved.

Total knee replacement with tibial tubercle osteotomy in rheumatoid patients with stiff knee.

PubMed

Eid, Ahmed Salem; Nassar, Wael Ahmed Mohamed; Fayyad, Tamer Abdelmeguid Mohamed

2016-11-01

Total knee arthroplasty (TKA) is a well-proven modality that can provide pain relief and restore mobility for rheumatoid arthritis (RA) patients with advanced joint destruction. Patellar ligament avulsion, especially in presence of poor bone quality and knee stiffness, is one of the special considerations that must be addressed in this unique population of patients. This study aimed to determine the functional results in a series of rheumatoid patients with stiff knee and end-stage joint destruction who underwent tibial tubercle osteotomy during TKA. Twenty-three knees in 20 patients (16 women; four men) at a mean age of 54 years with end-stage arthritis and knee stiffness due to RA were operated upon for TKA using tibial tubercle osteotomy as a step during the operation. Patients were reviewed clinically and radiographically with a minimum follow-up of two years. Complications were noted. Hospital for Special Surgery (HSS) score was recorded pre-operatively and at six and 12 months postoperatively. Union occurred at the osteotomy site in 21 of 23 cases. One case had deep venous thrombosis (DVT). There was no infection or periprosthetic fracture, and at last follow-up, no patient required revision. HSS score improved from 46 (15-60) pre-operatively to 85 (71-96) post-operatively. Tibial tubercle osteotomy during TKA in patients with RA and stiff knee is technically demanding yet proved to be effective in improving post-operative range of movement and minimising the complication of patellar ligament avulsion.

Cross-linked polyethylene does not reduce wear in total knee arthroplasty.

PubMed

Lasurt-Bachs, S; Torner, P; Maculé, F; Prats, E; Menéndez-García, F; Ríos-Guillermo, J; Torrents, A

To compare two different types of inserts: Ultra-high molecular weight polyethylene (UHMWPE) and cross-linked polyethylene with a quantitative and qualitative study of polyethylene wear particles in synovial fluid 3 years after total knee arthroplasty. A prospective, randomized, controlled cohort study with blinded evaluation was carried out on 25 patients undergoing staged bilateral total knee replacement, 6 months apart. Knee arthrocentesis was performed on 12 patients 3 years after surgery, and the polyethylene particles were analyzed. No significant differences were found in the number of particles generated by the two different types of inserts at 3 years from total knee arthroplasty (3,000×: x¯ cross-linked=849.7; x¯ UHMWPE=796.9; P=.63; 20,000×: x¯ cross-linked=66.3; x¯ UHMWPE=73.1; P=.76). Likewise, no differences in the probability of finding elongated (χ 2 =0.19; P=.66) or rounded (χ 2 =1.44; P=.23) particles in both types of inserts were observed. However, the probability of finding fibrillar particles is 3.08 times greater in UHMWPE. Cross-linked polyethylene does not significantly reduce the generation of polyethylene particles in patients with total knee arthroplasty, 3 years after the surgical procedure. Copyright © 2018 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Unsatisfactory Outcome of Arthrodesis Performed After Septic Failure of Revision Total Knee Arthroplasty

PubMed Central

Röhner, Eric; Windisch, Christoph; Nuetzmann, Katy; Rau, Max; Arnhold, Michael; Matziolis, Georg

2015-01-01

Background: Periprosthetic infection is one of the most dreaded orthopaedic complications. Current treatment procedures include one-stage or two-stage revision total knee arthroplasty. If the periprosthetic infection is no longer controllable after several revision total knee arthroplasties, many surgeons regard knee arthrodesis as a promising option. The aim of our study was to ascertain whether intramedullary nailing results in the suppression or eradication of an infection and to identify risk factors for persistent infection. Methods: All patients who had undergone intramedullary nailing following septic failure of revision total knee arthroplasty between 1997 and 2013 were included in the study. Pathogens, risk factors predisposing to persistent infection, and the rate of persistent infections were recorded. In addition, a visual analog scale (VAS) and Knee injury Osteoarthritis Outcome Score (KOOS), Knee Society Score (KSS), Lysholm, Short Form-36 (SF-36), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaires were completed to assess clinical outcomes and quality of life. Results: Twenty-six patients were included in the study. Thirteen (50%) had a persistent infection requiring additional revision surgery. Nineteen patients (73%) reported persistent pain (VAS score of >3). All scores showed marked impairment of quality of life. Conclusions: Intramedullary nailing following septic failure of revision total knee arthroplasty must be regarded with skepticism, and we cannot recommend it. Repeat revision total knee arthroplasty or amputation should be considered as an alternative in such difficult cases. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. PMID:25695981

Clinical Outcomes in Men and Women following Total Knee Arthroplasty with a High-Flex Knee: No Clinical Effect of Gender.

PubMed

Nassif, Jeffrey M; Pietrzak, William S

2015-01-01

While it is generally recognized that anatomical differences exist between the male and female knee, the literature generally refutes the clinical need for gender-specific total knee prostheses. It has been found that standard, unisex knees perform as well, or better, in women than men. Recently, high-flex knees have become available that mechanically accommodate increased flexion yet no studies have directly compared the outcomes of these devices in men and women to see if gender-based differences exist. We retrospectively compared the performance of the high-flex Vanguard knee (Biomet, Warsaw, IN) in 716 male and 1,069 female knees. Kaplan-Meier survivorship was 98.5% at 5.6-5.7 years for both genders. After 2 years, mean improvements in Knee Society Knee and Function scores for men and women (50.9 versus 46.3; 26.5 versus 23.1) and corresponding SF-12 Mental and Physical scores (0.2 versus 2.2; 13.7 versus 12.2) were similar with differences not clinically relevant. Postoperative motion gains as a function of preoperative motion level were virtually identical in men and women. This further confirms the suitability of unisex total knee prostheses for both men and women.

Correcting deformity in total knee arthroplasty: Techniques to avoid the release of collateral ligaments in severely deformed knees.

PubMed

Mullaji, A B; Shetty, G M

2016-01-01

Collateral ligament release is advocated in total knee arthroplasty (TKA) to deal with significant coronal plane deformities, but is also associated with significant disadvantages. We describe steps to avoid release of the collateral (superficial medial and lateral collateral) ligaments during TKA in severely deformed knees, while correcting deformity and balancing the knee. ©2016 The British Editorial Society of Bone & Joint Surgery.

Knee Extensor Strength and Gait Characteristics After Minimally Invasive Unicondylar Knee Arthroplasty vs Minimally Invasive Total Knee Arthroplasty: A Nonrandomized Controlled Trial.

PubMed

Braito, Matthias; Giesinger, Johannes M; Fischler, Stefan; Koller, Arnold; Niederseer, David; Liebensteiner, Michael C

2016-08-01

In light of the existing lack of evidence, it was the aim of this study to compare gait characteristics and knee extensor strength after medial unicondylar knee arthroplasty (MUKA) with those after total knee arthroplasty (TKA), given the same standardized minimally invasive surgery (MIS) approach in both groups. Patients scheduled for MIS-MUKA or MIS-TKA as part of clinical routine were invited to participate. A posterior cruciate ligament-retaining total knee design was used for all MIS-TKA. A 3-dimensional gait analysis was performed preoperatively with a VICON system and at 8 weeks postoperative to determine temporospatial parameters, ground reaction forces, joint angles, and joint moments. At the same 2 times, isokinetic tests were performed to obtain peak values of knee extensor torque. A multivariate analysis of variance was conducted and included the main effects time (before and after surgery) and surgical group and the group-by-time interaction effect. Fifteen MIS-MUKA patients and 17 MIS-TKA patients were eligible for the final analysis. The groups showed no differences regarding age, body mass index, sex, side treated, or stage of osteoarthritis. We determined neither intergroup differences nor time × group interactions for peak knee extensor torque or any gait parameters (temporospatial, ground reaction forces, joint angles, and joint moments). It is concluded that MUKA is not superior to TKA with regard to knee extensor strength or 3-dimensional gait characteristics at 8 weeks after operation. As gait characteristics and knee extensor strength are only 2 of the various potential outcome parameters (knee scores, activity scores…) and quadriceps strength might take a longer time to recover, our findings should be interpreted with caution. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Data Collection and Analysis Using Wearable Sensors for Monitoring Knee Range of Motion after Total Knee Arthroplasty

PubMed Central

Chiang, Chih-Yen; Chen, Kun-Hui; Liu, Kai-Chun; Hsu, Steen Jun-Ping; Chan, Chia-Tai

2017-01-01

Total knee arthroplasty (TKA) is the most common treatment for degenerative osteoarthritis of that articulation. However, either in rehabilitation clinics or in hospital wards, the knee range of motion (ROM) can currently only be assessed using a goniometer. In order to provide continuous and objective measurements of knee ROM, we propose the use of wearable inertial sensors to record the knee ROM during the recovery progress. Digitalized and objective data can assist the surgeons to control the recovery status and flexibly adjust rehabilitation programs during the early acute inpatient stage. The more knee flexion ROM regained during the early inpatient period, the better the long-term knee recovery will be and the sooner early discharge can be achieved. The results of this work show that the proposed wearable sensor approach can provide an alternative for continuous monitoring and objective assessment of knee ROM recovery progress for TKA patients compared to the traditional goniometer measurements. PMID:28241434

[The clinical evaluation of the lateral wedged insole fixed elastically on the subtalar joint of patients with osteoarthritis of the knee].

PubMed

Toda, Y

2001-06-01

We assessed the clinical efficacy of a lateral wedged insole with elastic fixation of the subtalar joint for conservative treatment of osteoarthritis of the knee. Novel insoles with elastic subtalar fixation (fixed insole) and a traditional shoe insert wedged insoles (inserted insole) were prepared. Seventy-one new female outpatients with osteoarthritis of the knee (knee OA) were treated with wedged insoles for 3 months. Randomization was performed according to birth date. The Severity Index of Lequesne, et al at the final assessment was compared with that at baseline in both the inserted and fixed insole groups. There were 37 participants in the inserted group and 34 participants in the fixed insole group. Regarding discomfort during nocturnal bed rest, 21 out of 34 (61%) participants were positive at the baseline assessment, however, only 8 out of 34 (27%) were positive at the final assessment in the fixed insole group (P = 0.033). In the fixed insole group, the number of participants complained immediate pain after walking was decreased from 28 (82%) at the baseline assessment to 17 (50%) at the final assessments (P = 0.0104). These significant differences were not found in the group with the inserted insole. Thus, clinical efficacy of lateral wedged insole may be emphasized with elastic fixation of the subtalar joint.

Load-bearing capacity of all-ceramic posterior inlay-retained fixed dental prostheses.

PubMed

Puschmann, Djamila; Wolfart, Stefan; Ludwig, Klaus; Kern, Matthias

2009-06-01

The purpose of this in vitro study was to compare the quasi-static load-bearing capacity of all-ceramic resin-bonded three-unit inlay-retained fixed dental prostheses (IRFDPs) made from computer-aided design/computer-aided manufacturing (CAD/CAM)-manufactured yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) frameworks with two different connector dimensions, with and without fatigue loading. Twelve IRFDPs each were made with connector dimensions 3 x 3 mm(2) (width x height) (control group) and 3 x 2 mm(2) (test group). Inlay-retained fixed dental prostheses were adhesively cemented on identical metal-models using composite resin cement. Subgroups of six specimens each were fatigued with maximal 1,200,000 loading cycles in a chewing simulator with a weight load of 25 kg and a load frequency of 1.5 Hz. The load-bearing capacity was tested in a universal testing machine for IRFDPs without fatigue loading and for IRFDPs that had not already fractured during fatigue loading. During fatigue testing one IRFDP (17%) of the test group failed. Under both loading conditions, IRFDPs of the control group exhibited statistically significantly higher load-bearing capacities than the test group. Fatigue loading reduced the load-bearing capacity in both groups. Considering the maximum chewing forces in the molar region, it seems possible to use zirconia ceramic as a core material for IRFDPs with a minimum connector dimension of 9 mm(2). A further reduction of the connector dimensions to 6 mm(2) results in a significant reduction of the load-bearing capacity.

Polyethylene wear in Oxford unicompartmental knee replacement: a retrieval study of 47 bearings.

PubMed

Kendrick, B J L; Longino, D; Pandit, H; Svard, U; Gill, H S; Dodd, C A F; Murray, D W; Price, A J

2010-03-01

The Oxford Unicompartmental Knee replacement (UKR) was introduced as a design to reduce polyethylene wear. There has been one previous retrieval study involving this implant, which reported very low rates of wear in some specimens but abnormal patterns of wear in others. There has been no further investigation of these abnormal patterns. The bearings were retrieved from 47 patients who had received a medial Oxford UKR for anteromedial osteoarthritis of the knee. None had been studied previously. The mean time to revision was 8.4 years (sd 4.1), with 20 having been implanted for over ten years. The macroscopic pattern of polyethylene wear and the linear penetration were recorded for each bearing. The mean rate of linear penetration was 0.07 mm/year. The patterns of wear fell into three categories, each with a different rate of linear penetration; 1) no abnormal macroscopic wear and a normal articular surface, n = 16 (linear penetration rate = 0.01 mm/year); 2) abnormal macroscopic wear and normal articular surfaces with extra-articular impingement, n = 16 (linear penetration rate = 0.05 mm/year); 3) abnormal macroscopic wear and abnormal articular surfaces with intra-articular impingement +/- signs of non-congruous articulation, n = 15 (linear penetration rate = 0.12 mm/year). The differences in linear penetration rate were statistically significant (p < 0.001). These results show that very low rates of polyethylene wear are possible if the device functions normally. However, if the bearing displays suboptimal function (extra-articular, intra-articular impingement or incongruous articulation) the rates of wear increase significantly.

Revision total knee arthroplasty for septic versus aseptic failure.

PubMed

Rajgopal, Ashok; Vasdev, Attique; Gupta, Himanshu; Dahiya, Vivek

2013-12-01

To compare the medium-term outcome of revision total knee arthroplasty (TKA) for septic versus aseptic failure. Records of 142 patients who underwent revision TKA by a single senior surgeon for septic (n=65) or aseptic (n=77) failure were reviewed. In the septic group, 67 knees in 42 women and 23 men were included. In the aseptic group, 88 knees in 51 women and 26 men were included. The Knee Society Score was measured. The Kaplan Meier survival curve at months 36, 60, and 95 was plotted, with revision as the end point. The survival rates at each specific time point between the 2 groups were compared using the Z test. The Knee Society Scores improved 18% from 51 to 69 in the septic group and 18% from 52 to 70 in the aseptic group (p=0.72). The range of motion improved 30% from 72 to 102 degrees in the septic group and 39% from 62 to 100 degrees in the aseptic group (p<0.001). Results of the 2 groups were similar in terms of the Knee Society Score, range of motion, and the Kaplan-Meier survivorship.

Infected total knee arthroplasty treated with arthrodesis using a modular nail.

PubMed

Waldman, B J; Mont, M A; Payman, K R; Freiberg, A A; Windsor, R E; Sculco, T P; Hungerford, D S

1999-10-01

Failed treatment of infected total knee replacement presents few attractive surgical options. Knee arthrodesis is challenging surgically and can be complicated by nonunion, malunion, or recurrent infection. Recently, a modular titanium intramedullary nail has been used in an attempt to reduce the incidence of nonunion and the rate of complications. In the present study, a review of the results of knee arthrodesis after infected total knee arthroplasty in 21 patients at three large academic institutions was performed. All patients were followed up for a mean of 2.4 years (range, 2-7.5 years). The mean age of the patients was 64 years. The mean number of previous operations was four (range, 2-9 operations). A solid arthrodesis was achieved without additional surgical treatment in 20 of 21 patients (95%). The mean time to fusion was 6.3 months. The one patient who suffered a nonunion achieved fusion after a subsequent bone grafting procedure. Based on the present study, intramedullary arthrodesis with a coupled titanium nail, is a reliable, effective method of achieving fusion after infection of a total knee arthroplasty. This procedure resulted in a high rate of fusion and a lower rate of complications when compared with traditional methods of arthrodesis.

Kinematic analysis of total knee prosthesis designed for Asian population.

PubMed

Low, F H; Khoo, L P; Chua, C K; Lo, N N

2000-01-01

In designing a total knee replacement (TKR) prosthesis catering for the Asian population, 62 sets of femur were harvested and analyzed. The morphometrical data obtained were found to be in good agreement with dimensions typical of the Asian knee and has reaffirmed the fact that Caucasian knees are generally larger than Asian knees. Subsequently, these data when treated using a multivariate statistical technique resulted in the establishment of major design parameters for six different sizes of femoral implants. An extra-small implant size with established dimensions and geometrical shape has surfaced from the study. The differences between the Asian knees and the Caucasian knees are discussed. Employing the established femoral dimensions and motion path of the knee joint, the articulating tibia profile was generated. All the sizes of implants were modeled using a computer-aided software package. Thereupon, these models that accurately fits the local Asian knee were transported into a dynamic and kinematic analysis software package. The tibiofemoral joint was modeled successfully as a slide curve joint to study intuitively the motion of the femur when articulating on the tibia surface. An optimal tibia profile could be synthesized to mimic the natural knee path motion. Details of the analysis are presented and discussed.

Early outcomes of patella resurfacing in total knee arthroplasty

PubMed Central

Clements, Warren J; Miller, Lisa; Whitehouse, Sarah L; Graves, Stephen E; Ryan, Philip

2010-01-01

Background Patella resurfacing in total knee arthroplasty is a contentious issue. The literature suggests that resurfacing of the patella is based on surgeon preference, and little is known about the role and timing of resurfacing and how this affects outcomes. Methods We analyzed 134,799 total knee arthroplasties using data from the Australian Orthopaedic Association National Joint Replacement Registry. Hazards ratios (HRs) were used to compare rates of early revision between patella resurfacing at the primary procedure (the resurfacing group, R) and primary arthroplasty without resurfacing (no-resurfacing group, NR). We also analyzed the outcomes of NR that were revised for isolated patella addition. Results At 5 years, the R group showed a lower revision rate than the NR group: cumulative per cent revision (CPR) 3.1% and 4.0%, respectively (HR = 0.75, p < 0.001). Revisions for patellofemoral pain were more common in the NR group (17%) than in the R group (1%), and “patella only” revisions were more common in the NR group (29%) than in the R group (6%). Non-resurfaced knees revised for isolated patella addition had a higher revision rate than patella resurfacing at the primary procedure, with a 4-year CPR of 15% and 2.8%, respectively (HR = 4.1, p < 0.001). Interpretation Rates of early revision of primary total knees were higher when the patella was not resurfaced, and suggest that surgeons may be inclined to resurface later if there is patellofemoral pain. However, 15% of non-resurfaced knees revised for patella addition are re-revised by 4 years. Our results suggest an early beneficial outcome for patella resurfacing at primary arthroplasty based on revision rates up to 5 years. PMID:19968604

Calcaneal stress fracture: an adverse event following total hip and total knee arthroplasty: a report of five cases.

PubMed

Miki, Takaaki; Miki, Takahito; Nishiyama, Akihiro

2014-01-15

Stress fractures have been reported to occur in the pubis, femoral neck, proximal part of the tibia, and fabella during the postoperative period following total knee or total hip arthroplasty. However, to our knowledge, calcaneal stress fractures after total hip or total knee arthroplasty have not been reported in the English-language literature. Most orthopaedic surgeons are not familiar with calcaneal stress fractures that may occur in elderly patients after a total knee or total hip arthroplasty. We retrospectively reviewed the clinical features, imaging findings, and bone mineral content of the proximal part of the femur and the distal end of the radius in five patients who had a calcaneal stress fracture after a total knee or total hip arthroplasty. All patients were women with a mean age of 76.8 years. All fractures occurred in the calcaneus on the same side as the arthroplasty. The fracture appeared at a mean of 10.2 weeks postoperatively. All patients reported heel pain on walking. Swelling and local heat were found in four and three patients, respectively. Pain was elicited by squeezing the calcaneus in all patients. Early radiographs had normal findings in two patients, and an irregular sclerotic line appeared later in the radiographs of all patients. All fractures were treated conservatively. Four fractures healed uneventfully, but one fracture displaced. All patients had osteoporosis. Calcaneal stress fractures during the postoperative period following total knee or total hip arthroplasty may not be as rare as previously thought. Because clinical symptoms of the fracture appear insidiously and radiographic findings are absent or subtle in the early stage, a high index of suspicion is needed for orthopaedic surgeons to make the correct diagnosis. Magnetic resonance imaging or repeated radiographs may be necessary to make the correct diagnosis when no abnormality is apparent on the initial radiograph.

Characterizing the recovery trajectories of knee range of motion for one year after total knee replacement.

PubMed

Mehta, Saurabh; Rigney, Andrew; Webb, Kyle; Wesney, Jacob; Stratford, Paul W; Shuler, Franklin D; Oliashirazi, Ali

2018-06-13

Retrospective analysis of routinely collected clinical data. This study modeled the recovery in knee flexion and extension range of motion (ROM) over 1 year after total knee replacement (TKR). Recovery after TKR has been characterized for self-reported pain and functional status. Literature describing target knee ROM at different follow-up periods after TKR is scarce. Data were extracted for patients who had undergone TKR at a tertiary care hospital at 2, 8, 12, 26, and 52 weeks after TKR. A linear mixed-effects growth model was constructed that investigated the following covariates age, sex, pre-TKR range, body mass index, duration of symptoms, and their interaction with weeks post TKR. Of the 559 patients included (age 64.8 ± 8.5 years), 370 were women and 189 were men. Knee ROM showed the greatest change during the first 12 weeks after TKR, plateauing by 26 weeks. For an average patient, knee flexion increased from approximately 100º 2 weeks post TKR to 117º 52 weeks post TKR. Knee extension increased from approximately 3º knee flexion 2 weeks post TKR to 1º flexion 52 weeks post TKR. The results showed that the maximum gains in knee ROM should be expected within the first 12 weeks with small changes occurring up to 26 weeks after TKR. In addition, age and presurgery knee ROM are associated with the gains in knee ROM and should be factored into the estimation of expected knee ROM at a given follow-up interval after TKR.

Effect of Tibial Posterior Slope on Knee Kinematics, Quadriceps Force, and Patellofemoral Contact Force After Posterior-Stabilized Total Knee Arthroplasty.

PubMed

Okamoto, Shigetoshi; Mizu-uchi, Hideki; Okazaki, Ken; Hamai, Satoshi; Nakahara, Hiroyuki; Iwamoto, Yukihide

2015-08-01

We used a musculoskeletal model validated with in vivo data to evaluate the effect of tibial posterior slope on knee kinematics, quadriceps force, and patellofemoral contact force after posterior-stabilized total knee arthroplasty. The maximum quadriceps force and patellofemoral contact force decreased with increasing posterior slope. Anterior sliding of the tibial component and anterior impingement of the anterior aspect of the tibial post were observed with tibial posterior slopes of at least 5° and 10°, respectively. Increased tibial posterior slope contributes to improved exercise efficiency during knee extension, however excessive tibial posterior slope should be avoided to prevent knee instability. Based on our computer simulation we recommend tibial posterior slopes of less than 5° in posterior-stabilized total knee arthroplasty. Copyright © 2015 Elsevier Inc. All rights reserved.

Soft-tissue tension total knee arthroplasty.

PubMed

Asano, Hiroshi; Hoshino, Akiho; Wilton, Tim J

2004-08-01

It is far from clear how best to define the proper strength of soft-tissue tensioning in total knee arthroplasty (TKA). We attached a torque driver to the Monogram balancer/tensor device and measured soft-tissue tension in full extension and 90 degrees flexion during TKA. In our surgical procedure, when we felt proper soft-tissue tension was being applied, the mean distraction force was noted to be 126N in extension and 121N in flexion. There was no significant correlation between soft-tissue tension and the postoperative flexion angle finally achieved. To the best of our knowledge, this is the first study to assess the actual distraction forces in relation to soft-tissue tension in TKA. Further study may reveal the most appropriate forces to achieve proper soft-tissue tension in the wide variety of circumstances presenting at knee arthroplasty.

Special features of total knee replacement in hemophilia.

PubMed

Rodriguez-Merchan, Emerito Carlos

2013-12-01

Total knee replacement is an operation frequently needed by hemophilia patients, which greatly improves their quality of life. This operation, however, carries a higher risk of bleeding and infection for hemophiliacs than it does for osteoarthritis sufferers. It is advisable to implant prosthetic components using antibiotic-loaded cement. It is essential to maintain a level of 100% of the replacement clotting factor for 2 weeks. Hematological treatment must be established, depending on the patient's factor levels and other pharmacokinetic parameters such as recovery and half-life, optimal doses and treatment time. It is preferable to use general anesthesia due to the risk of spinal bleeding. The lifespan of total knee replacement in hemophilic patients is shorter than in patients with osteoarthritis because of the increased risk of infection.

Oxidized zirconium versus cobalt-chromium against the native patella in total knee arthroplasty: Patellofemoral outcomes.

PubMed

Matassi, Fabrizio; Paoli, Tommaso; Civinini, Roberto; Carulli, Christian; Innocenti, Massimo

2017-10-01

Oxidized zirconium (OxZr) has demonstrated excellent mechanical properties in vitro when used against articular cartilage; less coefficient of friction and less chondral damage have been found when compared with cobalt-chromium (CoCr) implants. However, controversy exists as to whether implants with a zirconium femoral component articulate safely with a native patella in total knee arthroplasty (TKA). To answer this question, the clinical and radiographic results were analysed from a group of patients who underwent a TKA with patella retention; the OxZr versus CoCr femoral components were compared. The present study prospectively evaluated 83 knees of 74 patients from 2009 to 2010. Each patient was evaluated clinically (visual analogue scale, Knee Society score, patellar score) and radiographically (long leg standing radiograph, anterior-posterior and latero-lateral projections, axial view of the patella) pre-operatively and postoperatively with a mean follow-up of 4.47years. The patellar tilt and shift, and progression of patellofemoral osteoarthritis were calculated with the axial view. There were no patient reported adverse reactions and none of the evaluated prostheses failed. Both the clinical and radiographic evaluations showed no statistically significant between-group differences. No adverse events were observed clinically or radiologically. These results justify pursuing the use of oxidized zirconium as an alternative bearing surface for a femoral component associated with patellar retention in TKA. Published by Elsevier B.V.

[Mobility of a polyethylene tibial insert in a mobile total knee prosthesis].

PubMed

Castel, E; Roger, B; Camproux, A; Saillant, G

1999-03-01

We have studied the mobility of a mobile tibial implant in total knee arthroplasty (TKA) by a radiographical evaluation. We analyzed mobility of the polyethylene tibial insert of 15 "G2S" TKA implanted for one year or more. We established a dynamic radiographical evaluation. We used 3 weight-bearing radiographs: AP in extension and two lateral (one in extension and one at 90 degrees of flexion), two AP with femoral internal and external rotation, 2 strict lateral X-rays in neutral rotation in antero-posterior replacement with a 25 kilograms strength Telos, and 2 AP in varus and valgus with Telos. Wilcoxon's test and Fisher's exact test were used for statistical evaluation. Our study demonstrated preservation of the polyethylene mobility in tibial TKA implant in all movements: in rotation, in antero-posterior translation with Telos, and even in antero-posterior translation during physiological condition with flexion-extension weight-bearing radiographs. Statistical tests were very significant. We noticed that flexion induced anterior translation of tibial polyethylene when PCL was preserved. This study answered to our question whether mobility of TKA tibial implant persists after implantation. This mobility should reduce loosening forces to the tibia and stress in the polyethylene component. Now we have to determine the amplitude of mobility required to reach this objective.

[Clinical study on patellar replacement in total knee arthroplasty].

PubMed

Bao, Liang; Gao, Zhihui; Shi, Xiaoqiang; Fang, Xiaomin; Jin, Qunhua

2013-01-01

To evaluate the influence of patellar replacement on total knee arthroplasty by comparing with non patellar replacement. Between September 2010 and November 2010, 63 patients (63 knees) with osteoarthritis who met the selection criteria and underwent total knee arthroplasty, were randomly divided into 2 groups: patellar replacement in 32 cases (replacement group), non patellar replacement in 31 cases (non patellar replacement group). There was no significant difference in gender, age, disease duration, osteoarthritis grading, the clinical and functional scores of American Knee Society Score (KSS), the patellar tilt angle, tibiofemoral angle, and patellar ligament ratio between 2 groups (P > 0.05), they were comparable. After 6 weeks, 3, 6, and 12 months of operation, clinical and imaging evaluation methods were used to assessment the effectiveness. Primary healing of incision was obtained in all patients of 2 groups. Deep venous thrombosis occurred in 6 cases of replacement group and in 8 cases of non patellar replacement group. All patients were followed up 12 months. The postoperative incidence of anterior knee pain in replacement group was significantly lower than that in non patellar replacement group (P < 0.05) at 3, 6, and 12 months after operation. No significant difference was found in the postoperative KSS clinical score between 2 groups at each time point (P > 0.05). The joint function score of the replacement group was significantly higher than that of the non patellar replacement group at the other time point (P < 0.05) except the score at 6 weeks and 3 months. Significant difference was found in the patella score between 2 groups at 12 months (P < 0.05), but no significant difference at the other time points (P > 0.05). X-ray film showed no patellar fracture and dislocation, or loosening and breakage of internal fixation. At 12 months after operation, the tibiofemoral angle, the patellar ligament ratio, and the patellar tilt angle showed no significant

Effect of surgical closing in total knee arthroplasty at flexion or extension: a prospective, randomized study.

PubMed

Kömürcü, Erkam; Yüksel, Halil Yalçın; Ersöz, Murat; Aktekin, Cem Nuri; Hapa, Onur; Çelebi, Levent; Akbal, Ayla; Biçimoğlu, Ali

2014-12-01

The aim of this study was to evaluate the effect of knee position during wound closure (flexed vs. extended) in total knee arthroplasty on knee strength and function, as determined by knee society scores and isokinetic testing of extensor and flexor muscle groups. In a prospective, randomized, double-blind trial, 29 patients were divided in two groups: for Group 1 patients, surgical closing was performed with the knee extended, and for Group 2 patients, the knee flexed at 90°. All the patients were treated with the same anaesthesia method, surgical team, surgical technique, prosthesis type, and rehabilitation process. American Knee Society Score values and knee flexion degrees were recorded. Isokinetic muscle strength measurements of both knees in flexion and extension were taken using 60° and 180°/s angular velocity. The peak torque and total work values, isokinetic muscle strength differences, and total work difference values were calculated for surgically repaired and healthy knees. No significant difference in the mean American Knee Society Score values and knee flexion degrees was observed between the two groups. However, using isokinetic evaluation, a significant difference was found in the isokinetic muscle strength differences and total work difference of the flexor muscle between the two groups when patients were tested at 180°/s. Less loss of strength was detected in the isokinetic muscle strength differences of the flexor muscle in Group 2 (-4.2%) than in Group 1 (-23.1%). For patients undergoing total knee arthroplasty, post-operative flexor muscle strength is improved if the knee is flexed during wound closure. II.

Factors affecting the achievement of Japanese-style deep knee flexion after total knee arthroplasty using posterior-stabilized prosthesis with high-flex knee design.

PubMed

Niki, Yasuo; Takeda, Yuki; Harato, Kengo; Suda, Yasunori

2015-11-01

Achievement of very deep knee flexion after total knee arthroplasty (TKA) can play a critical role in the satisfaction of patients who demand a floor-sitting lifestyle and engage in high-flexion daily activities (e.g., seiza-sitting). Seiza-sitting is characterized by the knees flexed >145º and feet turned sole upwards underneath the buttocks with the tibia internally rotated. The present study investigated factors affecting the achievement of seiza-sitting after TKA using posterior-stabilized total knee prosthesis with high-flex knee design. Subjects comprised 32 patients who underwent TKA with high-flex knee prosthesis and achieved seiza-sitting (knee flexion >145º) postoperatively. Another 32 patients served as controls who were capable of knee flexion >145º preoperatively, but failed to achieve seiza-sitting postoperatively. Accuracy of femoral and tibial component positions was assessed in terms of deviation from the ideal position using a two-dimensional to three-dimensional matching technique. Accuracies of the component position, posterior condylar offset ratio and intraoperative gap length were compared between the two groups. The proportion of patients with >3º internally rotated tibial component was significantly higher in patients who failed at seiza-sitting (41 %) than among patients who achieved it (13 %, p = 0.021). Comparison of intraoperative gap length between patient groups revealed that gap length at 135º flexion was significantly larger in patients who achieved seiza-sitting (4.2 ± 0.4 mm) than in patients who failed at it (2.7 ± 0.4 mm, p = 0.007). Conversely, no significant differences in gap inclination were seen between the groups. From the perspective of surgical factors, accurate implant positioning, particularly rotational alignment of the tibial component, and maintenance of a sufficient joint gap at 135º flexion appear to represent critical factors for achieving >145º of deep knee flexion after TKA.

Effect of different postoperative limb positions on blood loss and range of motion in total knee arthroplasty: An updated meta-analysis of randomized controlled trials.

PubMed

Wu, Yuangang; Yang, Timin; Zeng, Yi; Si, Haibo; Li, Canfeng; Shen, Bin

2017-01-01

Postoperative limb positioning has been reported to be an efficient and simple way to reduce blood loss and improve range of motion following total knee arthroplasty (TKA). This meta-analysis was designed to compare the effectiveness of two different limb positions in primary TKA. A meta-analysis of the PubMed, CENTRAL, Web of Science, EMBASE and Google Search Engine electronic databases was performed. In this meta-analysis, two postoperative limb positions were considered: mild-flexion (flexion less than 60°) and high-flexion (flexion at 60° or more). The subgroups were analysed using RevMan 5.3. Nine RCTs were included with a total sample size of 913 patients. The mild- and high-flexion positions significantly reduced postoperative total blood loss (P = 0.04 and P = 0.01; respectively). Subgroup analysis indicated that knee flexion significantly reduced hidden blood loss when the knee was fixed in mild-flexion (P = 0.0004) and significantly reduced transfusion requirements (P = 0.03) and improved range of motion (ROM) (P < 0.00001) when the knee was fixed in high-flexion. However, the rates of wound-related infection, deep venous thrombosis (DVT) and pulmonary embolism (PE) did not significantly differ between the two flexion groups. This meta-analysis suggests that mild- and high-flexion positions have similar efficacy in reducing total blood loss. In addition, subgroup analysis indicates that the mild-flexion position is superior in decreasing hidden blood loss compared with high-flexion; the high-flexion position is superior to mild-flexion in reducing transfusion requirements and improving postoperative ROM. Thus, the use of the high-flexion position is a viable option to reduce blood loss in patients following primary TKA without increasing the risk of wound-related infection, DVT or PE. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Intra-operative periarticular multimodal injection in total knee arthroplasty: a local hospital experience in Hong Kong.

PubMed

Fan, J Ch

2018-04-01

Data from a local report revealed the superior outcome of regional anaesthesia and analgesia compared with general anaesthesia and intravenous patient-controlled analgesia in total knee arthroplasty. This retrospective study aimed to assess the efficacy of intra-operative periarticular multimodal injection in improving postoperative pain and reducing morphine consumption with patient-controlled analgesia after total knee arthroplasty in patients with knee osteoarthritis. From July 2005 to May 2009, 213 total knee arthroplasties without intra-operative periarticular multimodal injection (control group) were performed at a local hospital. From June 2009 to December 2012, 185 total knee arthroplasties were performed with intra-operative periarticular multimodal injection (cocktail group). The inclusion criteria were osteoarthritis of the knee, single method of anaesthesia (general or neuraxial), simple total knee arthroplasty without any metal augmentation or constraint, and postoperative patient-controlled analgesia. Postoperative patient-controlled morphine doses were compared. A total of 152 total knee arthroplasties were recruited to the cocktail group, and 89 to the control group. Duration of tourniquet application and preoperative knee score did not significantly correlate with morphine consumption by patient-controlled analgesia. Multimodal injection significantly decreased such consumption for 36 h. When injection was separately analysed for general and neuraxial anaesthesia, the effect lasted for 42 h and 24 h, respectively. Intra-operative periarticular multimodal injection decreased morphine consumption for up to 42 h postoperatively.

The role of the posterior cruciate ligament in total knee replacement

PubMed Central

Ritter, M. A.; Davis, K. E.; Meding, J. B.; Farris, A.

2012-01-01

Objectives The purpose of this study was to examine the effect of posterior cruciate ligament (PCL) retention, PCL recession, and PCL excision during cruciate-retaining total knee replacement. Methods A total of 3018 anatomic graduated component total knee replacements were examined; 1846 of these retained the PCL, 455 PCLs were partially recessed, and in 717 the PCL was completely excised from the back of the tibia. Results Clinical scores between PCL groups favored excision for flexion (p < 0.0001), and recession and retention for stairs (p < 0.0001). There was a mild difference in long-term all-cause aseptic survivorship between PCL-retained (96.4% at 15 years) combined with PCL-recessed groups (96.6% at 15 years) when compared with the PCL-excised group (95.0% at 15 years) (p = 0.0411, Wilcoxon; p = 0.0042, log-rank), as well as tibial or femoral loosening, which reported prosthesis survival of 97.8% at 15 years for PCL-retained knees, 98.2% for recessed knees, and 96.4% for excised knees (p = 0.0934, Wilcoxon; p = 0.0202, log-rank). Conclusions Despite some trade off in clinical performance, if the PCL is detached at the time of operation, conversion to a posterior-stabilised prosthesis may not be necessarily required as long as stability in the anteroposterior and coronal planes is achieved. PMID:23610673

Outcome following total knee arthroplasty in obese versus non-obese Asian patients.

PubMed

Goh, Graham Seow-Hng; Liow, Ming Han Lincoln; Mitra, Amit Kanta

2015-12-01

To compare the outcome following total knee arthroplasty (TKA) in obese and non-obese Asian patients. 27 obese patients were compared with 27 non-obese controls matched for age, gender, diagnosis (osteoarthritis), prosthesis, preoperative Knee Society knee and function scores, preoperative Oxford Knee Score, and follow-up duration. All TKAs were performed by a single surgeon. Patients were assessed at 6 months and 2 years for the range of motion, Knee Society knee and function scores, Oxford Knee Score, and Short Form-36 Health Survey (SF-36). The obese and non-obese groups did not differ significantly in pre- and post-operative variables: range of motion, Knee Society knee and function scores, Oxford Knee Score, and SF-36 score. Using revision as an end-point, implant survival was 100%. There were no intra- or post-operative complications in either group. Obese and non-obese Asian patients achieved a comparable outcome following TKA.

Effect of Body Mass Index on Reoperation and Complications After Total Knee Arthroplasty.

PubMed

Wagner, Eric R; Kamath, Atul F; Fruth, Kristin; Harmsen, William S; Berry, Daniel J

2016-12-21

High body mass index (BMI) is associated with increased rates of complications after total knee arthroplasty. To date, to our knowledge, studies have examined risk as a dichotomous variable using specific BMI thresholds. The purpose of this investigation was to quantify implant survival and the risk of common complications after total knee arthroplasty using BMI as a continuous variable. Using prospectively collected data from our institutional total joint registry, we analyzed 22,289 consecutive knees, in 16,136 patients, treated with primary total knee arthroplasty from 1985 to 2012. The mean BMI of these patients at the time of the surgical procedure was 31.3 kg/m (range, 11 to 69 kg/m). The Kaplan-Meier survival method was used to estimate survivorship, reoperations, and common complications, with associations of outcomes assessed using a Cox regression model. Utilizing smoothing spline parameterization, we found that reoperation (p < 0.001) and implant revision or removal rates (p < 0.001) increased with increasing BMI after total knee arthroplasty. Increasing BMI also was associated with increased rates of wound infection (hazard ratio [HR], 1.07; p < 0.001) and deep infection (HR, 1.08; p < 0.001) per unit of BMI over 35 kg/m. A BMI of 35 to 40 kg/m was associated with a higher rate of implant revision for aseptic loosening (p < 0.001) and for polyethylene wear (p < 0.001) compared with a BMI of 18 to 24.99 kg/m. There was no correlation between BMI and risk of venous thromboembolism, tibiofemoral instability, or need for knee manipulation. The rates of reoperation, implant revision or removal, and many common complications after total knee arthroplasty were strongly associated with BMI. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Results of computer assisted mini-incision subvastus approach for total knee arthroplasty.

PubMed

Turajane, Thana; Larbpaiboonpong, Viroj; Kongtharvonskul, Jatupon; Maungsiri, Samart

2009-12-01

Mini-incision subvastus approach is soft tissue preservation of the knee. Advantages of the mini-incision subvastus approach included reduced blood loss, reduced pain, self rehabilitation and faster recovery. However, the improved visualization, component alignment, and more blood preservation have been debatable to achieve the better outcome and preventing early failure of the Total Knee Arthroplasty (TKA). The computer navigation has been introduced to improve alignment and blood loss. The purpose of this study was to evaluate the short term outcomes of the combination of computer assisted mini-incision subvastus approach for Total Knee Arthroplasty (CMS-TKA). A prospective case series of the initial 80 patients who underwent computer assisted mini-incision subvastus approach for CMS-TKA from January 2007 to October 2008 was carried out. The patients' conditions were classified into 2 groups, the simple OA knee (varus deformity was less than 15 degree, BMI was less than 20%, no associated deformities) and the complex deformity (varus deformity was more than 15 degrees, BMI more was than 20%, associated with flexion contractor). There were 59 patients in group 1 and 21 patients in group 2. Of the 80 knees, 38 were on the left and 42 on the right. The results of CMS-TKA [the mean (range)] in group 1: group 2 were respectively shown as the incision length [10.88 (8-13): 11.92 (10-14], the operation time [118 (111.88-125.12): 131 (119.29-143.71) minutes, lateral releases (0 in both groups), postoperative range of motion in flexion [94.5 (90-100): 95.25 (90-105) degree] and extension [1.75 (0-5): 1.5 (0-5) degree] Blood loss in 24 hours [489.09 (414.7-563.48): 520 (503.46-636.54) ml] and blood transfusion [1 (0-1) unit? in both groups], Tibiofemoral angle preoperative [Varus = 4 (varus 0-10): Varus = 17.14 (varus 15.7-18.5) degree, Tibiofemoral angle postoperative [Valgus = 1.38 (Valgus 0-4): Valgus = 2.85 (valgus 2.1-3.5) degree], Tibiofemoral angle outlier (85% both

Knee joint biomechanics and neuromuscular control during gait before and after total knee arthroplasty are sex-specific.

PubMed

Astephen Wilson, Janie L; Dunbar, Michael J; Hubley-Kozey, Cheryl L

2015-01-01

The future of total knee arthroplasty (TKA) surgery will involve planning that incorporates more patient-specific characteristics. Despite known biological, morphological, and functional differences between men and women, there has been little investigation into knee joint biomechanical and neuromuscular differences between men and women with osteoarthritis, and none that have examined sex-specific biomechanical and neuromuscular responses to TKA surgery. The objective of this study was to examine sex-associated differences in knee kinematics, kinetics and neuromuscular patterns during gait before and after TKA. Fifty-two patients with end-stage knee OA (28 women, 24 men) underwent gait and neuromuscular analysis within the week prior to and one year after surgery. A number of sex-specific differences were identified which suggest a different manifestation of end-stage knee OA between the sexes. Copyright © 2014 Elsevier Inc. All rights reserved.

A randomised, controlled trial of circumpatellar electrocautery in total knee replacement without patellar resurfacing.

PubMed

van Jonbergen, H P W; Scholtes, V A B; van Kampen, A; Poolman, R W

2011-08-01

The efficacy of circumpatellar electrocautery in reducing the incidence of post-operative anterior knee pain is unknown. We conducted a single-centre, outcome-assessor and patient-blinded, parallel-group, randomised, controlled trial to compare circumpatellar electrocautery with no electrocautery in total knee replacement in the absence of patellar resurfacing. Patients requiring knee replacement for primary osteoarthritis were randomly assigned circumpatellar electrocautery (intervention group) or no electrocautery (control group). The primary outcome measure was the incidence of anterior knee pain. A secondary measure was the standardised clinical and patient-reported outcomes determined by the American Knee Society scores and the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index. A total of 131 knees received circumpatellar electrocautery and 131 had no electrocautery. The overall incidence of anterior knee pain at follow-up at one year was 26% (20% to 31%), with 19% (12% to 26%) in the intervention group and 32% (24% to 40%) in the control group (p = 0.02). The relative risk reduction from electrocautery was 40% (9% to 61%) and the number needed to treat was 7.7 (4.3 to 41.4). The intervention group had a better mean total WOMAC score at follow-up at one year compared with the control group (16.3 (0 to 77.7) versus 21.6 (0 to 76.7), p = 0.04). The mean post-operative American Knee Society knee scores and function scores were similar in the intervention and control groups (knee score: 92.4 (55 to 100) versus 90.4 (51 to 100), respectively (p = 0.14); function score: 86.5 (15 to 100) versus 84.5 (30 to 100), respectively (p = 0.49)). Our study suggests that in the absence of patellar resurfacing electrocautery around the margin of the patella improves the outcome of total knee replacement.

Mortality After Total Knee and Total Hip Arthroplasty in a Large Integrated Health Care System.

PubMed

Inacio, Maria C S; Dillon, Mark T; Miric, Alex; Navarro, Ronald A; Paxton, Elizabeth W

2017-01-01

The number of excess deaths associated with elective total joint arthroplasty in the US is not well understood. To evaluate one-year postoperative mortality among patients with elective primary and revision arthroplasty procedures of the hip and knee. A retrospective analysis was conducted of hip and knee arthroplasties performed in 2010. Procedure type, procedure volume, patient age and sex, and mortality were obtained from an institutional total joint replacement registry. An integrated health care system population was the sampling frame for the study subjects and was the reference group for the study. Standardized 1-year mortality ratios (SMRs) and 95% confidence intervals (CIs) were calculated. A total of 10,163 primary total knee arthroplasties (TKAs), 4963 primary total hip arthroplasties (THAs), 606 revision TKAs, and 496 revision THAs were evaluated. Patients undergoing primary THA (SMR = 0.6, 95% CI = 0.4-0.7) and TKA (SMR = 0.4, 95% CI = 0.3-0.5) had lower odds of mortality than expected. Patients with revision TKA had higher-than-expected mortality odds (SMR = 1.8, 95% CI = 1.1-2.5), whereas patients with revision THA (SMR = 0.9, 95% CI = 0.4-1.5) did not have higher-than-expected odds of mortality. Understanding excess mortality after joint surgery allows clinicians to evaluate current practices and to determine whether certain groups are at higher-than-expected mortality risk after surgery.

Chronic Quadriceps Tendon Rupture After Total Knee Arthroplasty Augmented With Synthetic Mesh.

PubMed

Ormaza, Amaia; Moreta, Jesús; Mosquera, Javier; de Ugarte, Oskar Sáez; Mozos, José Luis Martinez-de Los

2017-01-01

Tear of the quadriceps tendon after revision or primary total knee arthroplasty is a rare complication, but when it occurs, this injury has serious functional consequences. In complete tears, the outcome of direct repair is unpredictable, and several authors recommend that the suture should be reinforced. Several techniques have been described, including the use of autografts, allografts, and synthetic mesh. The goal of this study was to assess the outcomes of a reconstruction technique augmented with synthetic mesh. A retrospective study was performed involving 3 patients who had chronic partial quadriceps tendon tear after total knee revision. In 2 cases, proximal quadriceps release was performed. When conservative management failed, surgical reconstruction with suture reinforced with synthetic mesh was attempted. The knee was immobilized in full extension for 6 weeks after the surgical procedure. A minimum follow-up of 12 months was required to assess results. All reconstructions showed clinical success at a mean follow-up of 19 months. Mean Knee Society Score improved from 55.7 to 87.3, with average postoperative extensor lag of 3.3° (range, 0°-10°). The mean visual analog scale pain score was 2.3 (range, 0-4). No complications were reported. Synthetic mesh has previously been shown to be an effective treatment for patellar tendon repairs after total knee replacement, but there have been few articles on quadriceps rupture. Surgical reconstruction with synthetic mesh is a viable option that provides good functional outcomes in chronic quadriceps tendon rupture after total knee arthroplasty. [Orthopedics. 2017; 40(1):38-42.]. Copyright 2016, SLACK Incorporated.

Cartilage Thickening in Early Radiographic Human Knee Osteoarthritis –Within-Person, Between-Knee Comparison

PubMed Central

Cotofana, Sebastian; Buck, Robert; Wirth, Wolfgang; Roemer, Frank; Duryea, Jeff; Nevitt, Michael; Eckstein, Felix

2012-01-01

Objective To determine whether the presence of definite osteophytes (in absence of joint space narrowing [JSN]) by radiograph is associated with (subregional) increases in cartilage thickness, in a within-person, between-knee cross-sectional comparison of participants in the Osteoarthritis Initiative (OAI). Based on previous results, external medial (ecMF) and external lateral weight-bearing femoral (ecLF) subregions were selected as primary endpoints. Methods Both knees of 61 (of 4798) OAI participants displayed definite tibial or femoral marginal osteophytes and no JSN in one knee, and no signs of radiographic OA in the contra-lateral knee; this being confirmed by an expert central reader. In these participants, cartilage thickness was measured in 16 femorotibial subregions of each knee, based on sagittal DESSwe magnetic resonance images. Location-specific joint space width from fixed flexion radiographs was determined using dedicated software. Location-specific associations of osteophytes with cartilage thickness were evaluated using paired t-tests and mixed effect models. Results Of the 61 participants, 48% had only medial, 36% only lateral, and 16% bi-compartmental osteophytes. Osteophyte knees had significantly thicker cartilage than contra-lateral non-osteophyte knees in the ecMF (+71±223μm, equivalent to +5.5%, p=0.015) and ecLF (+64±195μm, +4.1%, p=0.013). No significant differences between knees were noted in other subregions, nor in joint space width. Cartilage thickness in ecMF and ecLF was significantly associated with tibial osteophytes in the same (medial or lateral) compartment (p=0.003). Conclusion Knees with early radiographic OA display thicker cartilage than (contra-lateral) knees without radiographic findings of OA, specifically in the external femoral subregions of compartments with marginal osteophytes. PMID:22556039

Five year survival analysis of an oxidised zirconium total knee arthroplasty.

PubMed

Holland, Philip; Santini, Alasdair J A; Davidson, John S; Pope, Jill A

2013-12-01

Zirconium total knee arthroplasties theoretically have a low incidence of failure as they are low friction, hard wearing and hypoallergenic. We report the five year survival of 213 Profix zirconium total knee arthroplasties with a conforming all polyethylene tibial component. Data was collected prospectively and multiple strict end points were used. SF12 and WOMAC scores were recorded pre-operatively, at three months, at twelve months, at 3 years and at 5 years. Eight patients died and six were "lost to follow-up". The remaining 199 knees were followed up for five years. The mean WOMAC score improved from 56 to 35 and the mean SF12 physical component score improved from 28 to 34. The five year survival for failure due to implant related reasons was 99.5% (95% CI 97.4-100). This was due to one tibial component becoming loose aseptically in year zero. Our results demonstrate that the Profix zirconium total knee arthroplasty has a low medium term failure rate comparable to the best implants. Further research is needed to establish if the beneficial properties of zirconium improve long term implant survival. Copyright © 2012 Elsevier B.V. All rights reserved.

Simultaneous bilateral total knee and ankle arthroplasty as a single surgical procedure.

PubMed

Pagenstert, Geert; Hintermann, Beat

2011-10-13

Simultaneous osteoarthritis (OA) of the ankle joint complicates primary total knee arthroplasty (TKA). In such cases, rehabilitation of TKA is limited by debilitating ankle pain, but varus or valgus ankle arthritis may even compromise placement of knee prosthetic components. We present a patient with simultaneous bilateral valgus and patellofemoral OA of the knees and bilateral varus OA of the ankle joints that equally contributed to overall disability. This 63 years old, motivated and otherwise healthy patient was treated by simultaneous bilateral total knee and ankle arthroplasty (quadruple total joint arthroplasty, TJA) during the same anesthesia. Two years outcome showed excellent alignment and function of all four replaced joints. Postoperative time for rehabilitation, back to work (6th week) and hospital stay (12 days) of this special patient was markedly reduced compared to the usual course of separate TJA. Simultaneous quadruple TJA in equally disabling OA of bilateral deformed knees and ankles resulted in a better functional outcome and faster recovery compared to the average reported results after TKA and TAA in literature. However, careful preoperative planning, extensive patient education, and two complete surgical teams were considered essential for successful performance. To the best of our knowledge this is the first case report in literature about quadruple major total joint arthroplasty implanted during the same anesthesia in the same patient.

[Total knee arthroplasty in 2014 : Results, expectations, and complications].

PubMed

Matziolis, G; Röhner, E

2015-04-01

Aseptic loosening seems to have become a minor problem in total knee arthroplasty. In contrast to that, new challenges are defined by changing patients' expectations. Beside reduction of pain and improving mobility, modern implants should not be noticed as such and should not limit sports activities. In this paper, a summary of the development and the current situation of total knee arthroplasty (e.g., implantation numbers, hospitality, operation time, and infection rates) are provided. The data are compared in an international context. In addition, current trends and developments from recent years are shown and rated according to the literature. The paper is based on a literature search (PubMed) and analyses of published official statistical data and expert recommendations. Implantation numbers have been declining gradually in Germany since 2009. In 2013, 127,077 total knee arthroplasties were implanted. In contrast, the number of revision operations has increased gradually during the last decade. In addition, hospital stay and operation time have declined. The development of implants, instruments, and operation techniques results from changing patients' expectations. All innovations must be compared against the results of well-proven techniques. The arthroplasty register may be an instrument to evaluate the results of new techniques and implants in a broad clinical application in terms of survival.

Current surgical strategies for total arthroplasty in valgus knee

PubMed Central

Nikolopoulos, Dimitrios; Michos, Ioannis; Safos, George; Safos, Petros

2015-01-01

The majority of orthopaedic surgeons even currently agree that primary total arthroplasty in valgus knees with a deformity of more than ten degrees may prove challenging. The unique sets of bone and soft tissue abnormalities that must be addressed at the time of the operation make accurate axis restoration, component orientation and joint stability attainment a difficult task. Understanding the specific pathologic anatomic changes associated with the valgus knee is a prerequisite so as to select the proper surgical method, to optimize component position and restore soft-tissue balance. The purpose of this article is to review the valgus knee anatomical variations, to assess the best pre-operative planning and to evaluate how to choose the grade of constraint of the implant. It will also be underlying the up-to-date main approaches and surgical techniques be proposed in the English literature both for bone cuts and soft tissue management of valgus knees. PMID:26191494

The effectiveness and safety of aminocaproic acid for reducing blood loss in total knee and hip arthroplasty: A meta-analysis.

PubMed

Dong, Qiang; Zhang, Yinguang; Sun, Xiang; Hu, Fangke

2018-04-01

This meta-analysis aimed to evaluate the safety and efficacy of aminocaproic acid in total knee arthroplasty (TKA) and total hip arthroplasty (THA). The electronic databases include PubMed, Medline, Embase, Web of Science and the Cochrane Library from inception to January, 2018. Two reviewers abstracted total blood loss, hemoglobin drop, transfusion requirements, and postoperative complications. Data were using fixed-effects or random-effects models with weighted mean differences and risk difference for continuous and dichotomous variables, respectively. STATA 14.0 was used to perform the meta-analysis. Six studies encompassing 756 participants were retrieved for this meta-analysis. Our study indicated that intravenous aminocaproic acid was associated with a significantly reduction in total blood loss, hemoglobin drop and need for transfusion. Additionally, no increased risk of thromboembolic events were identified. Based on the present meta-analysis, intravenous aminocaproic acid is effective and safe in total knee and hip arthroplasty without increasing the incidence of thromboembolic events. Further studies should focus on the comparison of aminocaproic acid and TXA in arthroplasties. Copyright © 2018 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Improvement in the assessment of wear of total knee replacements using coordinate-measuring machine techniques.

PubMed

Blunt, L A; Bills, P J; Jiang, X-Q; Chakrabarty, G

2008-04-01

Total joint replacement is one of the most common elective surgical procedures performed worldwide, with an estimate of 1.5x 10(6) operations performed annually. Currently joint replacements are expected to function for 10-15 years; however, with an increase in life expectancy, and a greater call for knee replacement due to increased activity levels, there is a requirement to improve their function to offer longer-term improved quality of life for patients. Wear analysis of total joint replacements has long been an important means in determining failure mechanisms and improving longevity of these devices. The effectiveness of the coordinate-measuring machine (CMM) technique for assessing volumetric material loss during simulated life testing of a replacement knee joint has been proved previously by the present authors. The purpose of the current work is to present an improvement to this method for situations where no pre-wear data are available. To validate the method, simulator tests were run and gravimetric measurements taken throughout the test, such that the components measured had a known wear value. The implications of the results are then discussed in terms of assessment of joint functionality and development of standardized CMM-based product standards. The method was then expanded to allow assessment of clinically retrieved bearings so as to ascertain a measure of true clinical wear.

Kinematic alignment technique for total hip and knee arthroplasty

PubMed Central

Rivière, Charles; Lazic, Stefan; Villet, Loïc; Wiart, Yann; Allwood, Sarah Muirhead; Cobb, Justin

2018-01-01

Conventional techniques for hip and knee arthroplasty have led to good long-term clinical outcomes, but complications remain despite better surgical precision and improvements in implant design and quality. Technological improvements and a better understanding of joint kinematics have facilitated the progression to ‘personalized’ implant positioning (kinematic alignment) for total hip (THA) and knee (TKA) arthroplasty, the true value of which remains to be determined. By achieving a true knee resurfacing, the kinematic alignment (KA) technique for TKA aims at aligning the components with the physiological kinematic axes of the knee and restoring the constitutional tibio-femoral joint line frontal and axial orientation and soft-tissue laxity. The KA technique for THA aims at restoring the native ‘combined femoro-acetabular anteversion’ and the hip’s centre of rotation, and occasionally adjusting the cup position and design based on the assessment of the individual spine-hip relation. The key element for optimal prosthetic joint kinematics (hip or knee) is to reproduce the femoral anatomy. The transverse acetabular ligament (TAL) is the reference landmark to adjust the cup position. Cite this article: EFORT Open Rev 2018;3:98-105. DOI: 10.1302/2058-5241.3.170022 PMID:29657851

Physiotherapy in the management of total knee arthroplasty: a review.

PubMed

Akodu, A K; Giwa, S O; Akinbo, S R A; Ahmed, U A

2011-01-01

Although total knee arthroplasty (TKA) is considered the treatment of choice for patients with intractable pain and substantial functional disabilities who have not had acceptable relief and functional improvement after conservative treatment. It was found out that patients with total knee arthroplasty need physiotherapy intervention for pre-operative and post-operative management. To take a critical look at the importance of TKA following destruction of the knee joint, its indications and contraindications and to ascertain the current trend involved in the physiotherapy management of TKA. The current literature materials on physiotherapy management of TKA was reviewed. The aim of treatment is to maximize functionality and independence and to minimize complication such as deep vein thrombosis and pulmonary embolism by relieving pain using cryotherapy, improving range of motion with mobilization techniques, muscle strengthening, therapeutic exercise, transfer training, gait training and training of activities of daily living. These are administered as home programme or in organized groups led by a physiotherapist and has been shown to improve outcome related to physical activity after knee joint arthroplasty. It was concluded that interventions, including physiotherapy and functional exercises after discharge, is still beneficial after TKA.

Does patella position influence ligament balancing in total knee arthroplasty?

PubMed

Yoon, Jung-Ro; Oh, Kwang-Jun; Wang, Joon Ho; Yang, Jae-Hyuk

2015-07-01

In vivo comparative gap measurements were performed in three different patella positions (reduced, subluxated and everted) using offset-type-force-controlled-spreader-system. Prospectively, 50 knees were operated by total knee arthroplasty using a navigation-assisted gap-balancing technique. The offset-type-force-controlled-spreader-system was used for gap measurements. This commercially available instrument allows controllable tension in patella-reduced position. The mediolateral gaps of knee extension (0°) and flexion (90°) angle were recorded in three different patella positions; reduced, subluxated and everted. Any gap differences of more than 3 mm were considered as a meaningful difference. Correlation between the difference with the demographic data, preoperative radiologic alignment and intraoperative data was analysed. For statistical analysis, ANOVA and Pearson's correlation test were used. The gaps in patella eversion demonstrated smaller gaps both in knee extension and flexion position compared to the gaps of patella reduction position. The amount of decreased gaps was more definite in knee flexion position. Statistically significant difference was observed for the lateral gap of patella eversion compared to gap of patella reduction in knee flexion position (p < 0.05). There were notable cases of variability in knee flexion position. Significant portion of 12 (24 %) knees of patella subluxation and 33 (66 %) knees of patella evertion demonstrated either increased or decreased gaps in knee flexion position compared to the gaps of patella reduction position. The gaps in patella eversion demonstrated smaller gaps both in knee extension and flexion position compared to the gaps of patella reduction position. The amount of decreased gaps was more definite in knee flexion position. Therefore, the intraoperative patellar positioning has influence on the measurement of the joint gap. Keeping the patella in reduced position is important during gap balancing. I.

Load balance in total knee arthroplasty: an in vitro analysis.

PubMed

El-Hawary, Ron; Roth, Sandra E; King, Graham J W; Chess, David G; Johnson, James A

2006-09-01

One of the goals of total knee arthroplasty (TKA) is to balance the loads between the compartments of the knee. An instrumented load cell that measures compartment loads in real time is utilized to evaluate conventional, qualitative methods of achieving this balance. TKA was performed on 10 cadaveric knees. Prior to and after load balancing, compartment forces were measured at flexion angles of 0-90 degrees. Knees were randomly assigned into one of two groups, based upon whether or not the surgeons could visualize the load cell's output during balancing. Prior to attempting load balance, there were significant differences between the medial and lateral compartment loads for all knees (p < 0.05). After attempting balance with the aid of the load cell, there was equal load balance at all angles studied. Without the aid of the load cell, balance was not consistently achieved at every angle. Conventional load balancing techniques in TKA are not perfect. Copyright 2006 John Wiley & Sons, Ltd.

Revision total knee arthroplasty in the young patient: is there trouble on the horizon?

PubMed

Aggarwal, Vinay K; Goyal, Nitin; Deirmengian, Gregory; Rangavajulla, Ashwin; Parvizi, Javad; Austin, Matthew S

2014-04-02

The volume of total knee arthroplasties, including revisions, in young patients is expected to rise. The objective of this study was to compare the reasons for revision and re-revision total knee arthroplasties between younger and older patients, to determine the survivorship of revision total knee arthroplasties, and to identify risk factors associated with failure of revision in patients fifty years of age or younger. Perioperative data were collected for all total knee arthroplasty revisions performed from August 1999 to December 2009. A cohort of eighty-four patients who were fifty years of age or younger and a cohort of eighty-four patients who were sixty to seventy years of age were matched for the date of surgery, sex, and body mass index (BMI). The etiology of failure of the index total knee arthroplasty and all subsequent revision total knee arthroplasties was determined. Kaplan-Meier survival curves were used to evaluate the timing of the primary failure and the survivorship of revision knee procedures. Finally, multivariate Cox regression was used to calculate risk ratios for the influence of age, sex, BMI, and the reason for the initial revision on survival of the revision total knee arthroplasty. The most common reason for the initial revision was aseptic loosening (27%; 95% confidence interval [CI] = 19% to 38%) in the younger cohort and infection (30%; 95% CI = 21% to 40%) in the older cohort. Of the twenty-five second revisions in younger patients, 32% (95% CI = 17% to 52%) were for infection, whereas 50% (95% CI = 32% to 68%) of the twenty-six second revisions in the older cohort were for infection. Cumulative six-year survival rates were 71.0% (95% CI = 60.7% to 83.0%) and 66.1% (95% CI = 54.5% to 80.2%) for revisions in the younger and older cohorts, respectively. Infection and a BMI of ≥ 40 kg/m(2) posed the greatest risk of failure of revision procedures, with risk ratios of 2.731 (p = 0.006) and 2.934 (p = 0.009), respectively. The

Reproducibility of an optical measurement system for the clinical evaluation of active knee rotation in weight-bearing, healthy subjects.

PubMed

Testa, R; Chouteau, J; Viste, A; Cheze, L; Fessy, M-H; Moyen, B

2012-04-01

A knee is typically evaluated passively by a clinician during an office visit, without using dedicated measurement tools. When the knee is evaluated with the patient standing and actively participating in the movement, the results will differ than when the knee is passively moved through its range-of-motion by the surgeon. If a precise measurement system was available, it could provide additional information to the clinician during this evaluation. The goal of this study was to verify the reproducibility of a fast, flexible optical measurement system to measure rotational knee laxity during weight-bearing. Two passive reflective targets were placed on the legs of 11 subjects to monitor femur and tibia displacements in three dimensions. Subjects performed internal and external rotation movements with the knee extended or flexed 30°. During each movement, seven variables were measured: internal rotation, external rotation and overall laxity in extension and 30° flexion, along with neutral rotation value in 30° flexion. Measurement accuracy was also assessed and the right and left knees were compared. Reproducibility was assessed over two measurements sessions. The calculated intra-class correlation coefficient (ICC) for reproducibility was above 0.9 for five of the seven variables measured. The calculated ICC for the right/left comparison was above 0.75 for five of the seven variables measured. These results confirmed that the proposed system provides reproducible measurements. Our right/left comparison results were consistent with the published literature. This system is fast, reproducible and flexible, which makes it suitable for assessing various weight-bearing movements during clinical evaluations. Level III, experimental study. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

[Navigated implantation of total knee endoprostheses--a comparative study with conventional instrumentation].

PubMed

Jenny, J Y; Boeri, C

2001-01-01

A navigation system should improve the quality of a total knee prosthesis implantation in comparison to the classical, surgeon-controlled operative technique. The authors have implanted 40 knee total prostheses with an optical infrared navigation system (Orthopilot AESCULAP, Tuttlingen--group A). The quality of implantation was studied on postoperative long leg AP and lateral X-rays, and compared to a control group of 40 computer-paired total knee prostheses o the same model (Search Prosthesis, AESCULAP, Tuttlingen) implanted with a classical, surgeon-controlled technique (group B). An optimal mechanical femorotibial angle (3 degrees valgus to 3 degrees varus) was obtained by 33 cases in group A and 31 cases in group B (p > 0.05). Better results were seen for the coronal and sagittal orientation of both tibial and femoral components in group A. Globally, 26 cases of the group A and 12 cases of the group B were implanted in an optimal manner for all studied criteria (p < 0.01). The used navigation system allows a significant improvement of the quality of implantation of a knee total prosthesis in comparison to a classical, surgeon-controlled instrumentation. Long-term outcome could be consequently improved.

Lower Limbs Function and Pain Relationships after Unilateral Total Knee Arthroplasty

ERIC Educational Resources Information Center

Tali, Maie; Maaroos, Jaak

2010-01-01

The aim of the study was to evaluate gait characteristics, lower limbs joint function, and pain relationships associated with knee osteoarthritis of female patients before and 3 months after total knee arthroplasty at an outpatient clinic rehabilitation department. Gait parameters were registered, the active range of lower extremity joints was…

The Time Course of Knee Swelling Post Total Knee Arthroplasty and Its Associations with Quadriceps Strength and Gait Speed.

PubMed

Pua, Yong-Hao

2015-07-01

This study examines the time course of knee swelling post total knee arthroplasty (TKA) and its associations with quadriceps strength and gait speed. Eighty-five patients with unilateral TKA participated. Preoperatively and on post-operative days (PODs) 1, 4, 14, and 90, knee swelling was measured using bioimpedance spectrometry. Preoperatively and on PODs 14 and 90, quadriceps strength was measured using isokinetic dynamometry while fast gait speed was measured using the timed 10-meter walk. On POD1, knee swelling increased ~35% from preoperative levels after which, knee swelling reduced but remained at ~11% above preoperative levels on POD90. In longitudinal, multivariable analyses, knee swelling was associated with quadriceps weakness (P<0.01) and slower gait speed (P=0.03). Interventions to reduce post-TKA knee swelling may be indicated to improve quadriceps strength and gait speed. Copyright © 2015 Elsevier Inc. All rights reserved.

Preoperative methylprednisolone does not reduce loss of knee-extension strength after total knee arthroplasty

PubMed Central

Lindberg-Larsen, Viktoria; Bandholm, Thomas Q; Zilmer, Camilla K; Bagger, Jens; Hornsleth, Mette; Kehlet, Henrik

2017-01-01

Background and purpose Patients undergoing total knee arthroplasty (TKA) face challenges related to postoperative reduction in knee-extension strength. We evaluated whether inhibition of the inflammatory response by a single preoperative dose of methylprednisolone (MP) reduces the pronounced loss of knee-extension strength at discharge after fast-track TKA. Patients and methods 70 patients undergoing elective unilateral TKA were randomized (1:1) to preoperative intravenous (IV) MP 125 mg (group MP) or isotonic saline IV (group C). All procedures were performed under spinal anesthesia without tourniquet, and with a standardized multimodal analgesic regime. The primary outcome was change in knee-extension strength from baseline to 48 hours postoperatively. Secondary outcomes were knee joint circumference, functional performance using the Timed Up and Go (TUG) test, pain during the aforementioned tests, rescue analgesic requirements, and plasma C-reactive protein (CRP) changes. Results 61 patients completed the follow-up. The loss in quadriceps muscle strength was similar between groups; group MP 1.04 (0.22–1.91) Nm/kg (–89%) vs. group C 1.02 (0.22–1.57) Nm/kg (–88%). Also between-group differences were similar for knee circumference, TUG test, and pain scores. MP reduced the inflammatory response (CRP) at 24 hours postoperatively; group MP 33 (IQR 21–50) mg/L vs. group C 72 (IQR 58–92) mg/L (p < 0.001), and 48 hours postoperatively; group MP 83 (IQR 56–125) mg/L vs. group C 192 (IQR 147–265) mg/L (p < 0.001), respectively. Interpretation Preoperative systemic administration of MP 125 mg did not reduce the pronounced loss of knee-extension strength or other functional outcomes at discharge after fast-track TKA despite a reduced systemic inflammatory response. PMID:28657396

Effects of upright weight bearing and the knee flexion angle on patellofemoral indices using magnetic resonance imaging in patients with patellofemoral instability.

PubMed

Becher, Christoph; Fleischer, Benjamin; Rase, Marten; Schumacher, Thees; Ettinger, Max; Ostermeier, Sven; Smith, Tomas

2017-08-01

This study analysed the effects of upright weight bearing and the knee flexion angle on patellofemoral indices, determined using magnetic resonance imaging (MRI), in patients with patellofemoral instability (PI). Healthy volunteers (control group, n = 9) and PI patients (PI group, n = 16) were scanned in an open-configuration MRI scanner during upright weight bearing and supine non-weight bearing positions at full extension (0° flexion) and at 15°, 30°, and 45° flexion. Patellofemoral indices included the Insall-Salvati Index, Caton-Deschamp Index, and Patellotrochlear Index (PTI) to determine patellar height and the patellar tilt angle (PTA), bisect offset (BO), and the tibial tubercle-trochlear groove (TT-TG) distance to assess patellar rotation and translation with respect to the femur and alignment of the extensor mechanism. A significant interaction effect of weight bearing by flexion angle was observed for the PTI, PTA, and BO for subjects with PI. At full extension, post hoc pairwise comparisons revealed a significant effect of weight bearing on the indices, with increased patellar height and increased PTA and BO in the PI group. Except for the BO, no such changes were seen in the control group. Independent of weight bearing, flexing the knee caused the PTA, BO, and TT-TG distance to be significantly reduced. Upright weight bearing and the knee flexion angle affected patellofemoral MRI indices in PI patients, with significantly increased values at full extension. The observations of this study provide a caution to be considered by professionals when treating PI patients. These patients should be evaluated clinically and radiographically at full extension and various flexion angles in context with quadriceps engagement. Explorative case-control study, Level III.

Factors affecting wound ooze in total knee replacement.

PubMed

Butt, U; Ahmad, R; Aspros, D; Bannister, G C

2011-01-01

Wound ooze is common following total knee arthroplasty (TKA) and persistent wound infection is a risk factor for infection, and increased length and cost of hospitalisation. We undertook a prospective study to assess the effect of tourniquet time, peri-articular local anaesthesia and surgical approach on wound oozing after TKA. The medial parapatellar approach was used in 59 patients (77%) and subvastus in 18 patients (23%). Peri-articular local anaesthesia (0.25% Bupivacaine with 1:1,000,000 adrenalin) was used in 34 patients (44%). The mean tourniquet time was 83 min (range, 38-125 min). We found a significant association between cessation of oozing and peri-articular local anaesthesia (P = 0.003), length of the tourniquet time (P = 0.03) and the subvastus approach (P = 0.01). Peri-articular local anaesthesia, the subvastus approach and shorter tourniquet time were all associated with less wound oozing after total knee arthroplasty.

Anterior knee pain and evidence of osteoarthritis of the patellofemoral joint should not be considered contraindications to mobile-bearing unicompartmental knee arthroplasty: a 15-year follow-up.

PubMed

Hamilton, T W; Pandit, H G; Maurer, D G; Ostlere, S J; Jenkins, C; Mellon, S J; Dodd, C A F; Murray, D W

2017-05-01

It is not clear whether anterior knee pain and osteoarthritis (OA) of the patellofemoral joint (PFJ) are contraindications to medial unicompartmental knee arthroplasty (UKA). Our aim was to investigate the long-term outcome of a consecutive series of patients, some of whom had anterior knee pain and PFJ OA managed with UKA. We assessed the ten-year functional outcomes and 15-year implant survival of 805 knees (677 patients) following medial mobile-bearing UKA. The intra-operative status of the PFJ was documented and, with the exception of bone loss with grooving to the lateral side, neither the clinical or radiological state of the PFJ nor the presence of anterior knee pain were considered a contraindication. The impact of radiographic findings and anterior knee pain was studied in a subgroup of 100 knees (91 patients). There was no relationship between functional outcomes, at a mean of ten years, or 15-year implant survival, and pre-operative anterior knee pain, or the presence or degree of cartilage loss documented intra-operatively at the medial patella or trochlea, or radiographic evidence of OA in the medial side of the PFJ. In 6% of cases there was full thickness cartilage loss on the lateral side of the patella. In these cases, the overall ten-year function and 15-year survival was similar to those without cartilage loss; however they had slightly more difficulty with descending stairs. Radiographic signs of OA seen in the lateral part of the PFJ were not associated with a definite compromise in functional outcome or implant survival. Severe damage to the lateral side of the PFJ with bone loss and grooving remains a contraindication to mobile-bearing UKA. Less severe damage to the lateral side of the PFJ and damage to the medial side, however severe, does not compromise the overall function or survival, so should not be considered to be a contraindication. However, if a patient does have full thickness cartilage loss on the lateral side of the PFJ they may

Do Knee Bracing and Delayed Weight Bearing Affect Mid-Term Functional Outcome after Anterior Cruciate Ligament Reconstruction?

PubMed

Di Miceli, Riccardo; Marambio, Carlotta Bustos; Zati, Alessandro; Monesi, Roberta; Benedetti, Maria Grazia

2017-12-01

Purpose  The aim of this study was to assess the effect of knee bracing and timing of full weight bearing after anterior cruciate ligament reconstruction (ACLR) on functional outcomes at mid-term follow-up. Methods  We performed a retrospective study on 41 patients with ACLR. Patients were divided in two groups: ACLR group, who received isolated ACL reconstruction and ACLR-OI group who received ACL reconstruction and adjunctive surgery. Information about age at surgery, bracing, full or progressive weight bearing permission after surgery were collected for the two groups. Subjective IKDC score was obtained at follow-up. Statistical analysis was performed to compare the two groups for IKDC score. Subgroup analysis was performed to assess the effect of postoperative regimen (knee bracing and weight bearing) on functional outcomes. Results  The mean age of patients was 30.8 ± 10.6 years. Mean IKDC score was 87.4 ± 13.9. The mean follow-up was 3.5 ± 1.8 years. Twenty-two (53.7%) patients underwent ACLR only, while 19 (46.3%) also received other interventions, such as meniscal repair and/or collateral ligament suture. Analysis of overall data showed no differences between the groups for IKDC score. Patients in the ACLR group exhibited a significantly better IKDC score when no brace and full weight bearing after 4 weeks from surgery was prescribed in comparison with patients who worn a brace and had delayed full weight bearing. No differences were found with respect to the use of brace and postoperative weight bearing regimen in the ACLR-OI group. Conclusion  Brace and delayed weight bearing after ACLR have a negative influence on long-term functional outcomes. Further research is required to explore possible differences in the patients operated on ACLR and other intervention with respect to the use of a brace and the timing of full weight bearing to identify optimal recovery strategies. Level of Evidence  Level III, retrospective observational