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Objective: To identify the presence and distribution of histopathological features of synovial inflammation and tissue damage, and to test their associations with ultrasound (US) imaging measures of synovitis and patient-reported measures of pain in knee osteoarthritis (OA)., Design: In the cross-sectional study of 122 patients undergoing surgery for painful late-stage (Kellgren-Lawrence Grade 3 or 4) knee OA, we compared US measures of synovitis (n = 118) and pain (Knee Injury and Osteoarthritis Outcome Score) to histopathological measures of inflammation vs. synovial tissue damage in synovial tissue biopsies. Associations of histopathological features with US measures of inflammation or pain were assessed using linear or logistic regression while controlling for covariates., Results: Histopathological features of inflammation were associated with higher odds of moderate/severe US synovitis (odds ratio [OR] = 1.34 [95%CI 1.04, 1.74), whereas features of synovial tissue damage were associated with lower odds of moderate/severe US synovitis (OR = 0.77 [95%CI 0.57, 1.03]). Worse histopathological scores for synovial tissue damage were associated with more pain (-1.47 [95%CI -2.88, -0.05]), even while adjusting for synovial inflammation (-1.61 [95%CI -3.12, -0.10])., Conclusions: Synovial tissue damage is associated with pain in late-stage knee OA, independent from inflammation and radiographic damage. These novel findings suggest that preventing synovial tissue damage may be an important goal of disease-modifying OA therapy., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: The objective of this study was to identify the rate and risk factors for revision total knee arthroplasty (TKA) within the first 5 years postoperative. Our secondary objective was to identify the rate of additional surgical procedures and death., Methods: We conducted a retrospective cohort study among patients in Ontario, Canada who underwent an elective, primary TKA between April 1, 2007, and March 31, 2014, for osteoarthritis. We excluded patients under 40 years and who had undergone a TKA within the previous 15 years. Our final study cohort included 94,193 patients. We reported the proportion of the study cohort who experienced revision surgery within 2 and 5 years of the primary TKA; secondary surgery within 5 years. We conducted Cochran-Armitage tests for trends to assess changes in the proportion of patients who experienced each of the study outcomes, and multivariable logistic regressions to evaluate predictors of a revision TKA., Results: There were 3,112 (3.3%) patients who had a revision within 5 years, and 1,866 (2.0%) within 2 years of their primary TKA. 3,316 (3.5%) had a secondary surgery (0.6% patellar resurfacing; 1.6% manipulation; 1.3% synovectomy; 0.5% washout; 0.9% debridement). Lower age, men, lower income, higher comorbidity score, depression, previous arthroscopy, lower surgeon volume, and general anesthesia were all significant positive predictors of revision., Conclusions: In our study cohort, 2.0% of patients had a revision TKA within 2 years, and 3.3% within 5 years of their primary TKA. Preoperative identification of risk factors may reduce the future prevalence of revision TKAs., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Approximately 20% of patients are dissatisfied with their total knee arthroplasty (TKA). Identifying patients likely to be dissatisfied early in the recovery process could help reduce the number of dissatisfied patients. The purpose of this study was to create an easily administered short questionnaire to identify patients likely to be dissatisfied at 1 year post surgery early in the recovery process., Methods: The study included 275 patients who underwent primary TKA for osteoarthritis. Individual 3-month postsurgery questionnaire items from the Knee Injury and Osteoarthritis Outcome Score and Knee Society Knee Scoring System were pooled together and used as candidate items to create 3 different short questionnaires. Items included in each questionnaire were selected using least absolute shrinkage and selection operator logistic regressions, a backward elimination method, and theory-based approaches. The area under the curve for each short questionnaire was calculated to evaluate predictive performances., Results: All 3 questionnaires contained a small number of items and appeared to successfully predict 1-year postsurgery dissatisfaction early in the recovery process. The least absolute shrinkage and selection operator logistic regression, backward elimination, and theory-based questionnaires were comprised of 4, 7, and 5 items and had the area under the curve scores of 0.893, 0.902, and 0.890, respectively. A question evaluating rising from sitting and activities of daily living appeared in all of the created questionnaires., Conclusion: A short questionnaire that is easy to administer and interpret can effectively predict TKA patient dissatisfaction at 1 year post surgery early in the recovery process., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: To support primary care physicians (PCPs) and their patients with knee osteoarthritis (OA), we created a series of evidence-based whiteboard educational videos for patients with knee OA. In a previous study we piloted these videos with patients to understand their acceptability and impact. The purpose of this study was to explore PCPs' perspectives to understand the utility of novel patient education videos to support management., Materials and Method: We conducted a qualitative descriptive study using semi-structured interviews of newly practicing and resident PCPs after watching a series of patient education videos. A thematic analysis approach was used combining both inductive and research question driven coding, category formation, and theme identification., Results: Ten participants were included. Barriers to optimal management were identified including the challenge of patient adherence and access to non-operative treatments. PCPs indicated that the videos would support their management of patients with knee OA by (1) supporting credibility and building trust with their patient, (2) reinforcing patient understanding, and (3) enhancing their own management of patients., Conclusion: Future implementation of these resources with attention to barriers that may limit uptake is necessary and may optimize management of knee OA in primary care.IMPLICATIONS FOR REHABILITATIONThe provision of patient educational materials may support patient buy-in regarding appropriate management, enhance patient understanding, and improve physicians' future practice.Viewing these videos could potentially improve physicians' future resource use, recommendation of non-operative treatments, and the quality of their total knee replacement referrals, which has benefits to both the patient and the healthcare system.Perceived barriers to implementing evidence-based recommendations may pose a challenge for patients and clinicians and should be considered to help facilitate the uptake of educational interventions.

Purpose: To optimize non-operative management and decision making surrounding TKR we created educational whiteboard videos for patients with knee OA. The purpose of this study was to pilot our educational videos with end-users (patients) to determine patients' experiences and perspectives regarding the content and clarity of videos and to better understand their potential impact on patient's health behaviour., Materials and Methods: This was a mixed methods evaluation, using a qualitative descriptive approach, of patients attending their first consultation with an arthroplasty surgeon for TKR. We conducted in-depth semi-structured interviews with patients. Three members of the research team coded data independently, implementing a thematic analysis., Results: Thirteen participants were included. Participants indicated that the videos enhanced their confidence and clarity surrounding their decision to undergo TKR. The videos also addressed several knowledge gaps in their understanding of OA management. Barriers to uptake of the education were identified including limited access to PTs and the challenge of weight loss. Conclusions : The current educational intervention was valued by patients with knee OA. Implementation of these videos may have important implications for patients, providers, and our health care system.IMPLICATIONS FOR REHABILITATIONPatients with knee OA referred by primary care physicians to arthroplasty surgeons have knowledge gaps that may influence their self-management and decision making surrounding their condition.Educational materials can address these gaps and support patients in their understanding and management of their condition, which may have important downstream implications.Barriers to accessing non-operative care including physiotherapy must be pre-emptively addressed to ensure that enhanced knowledge is met with improved access for patients.

Background: Approximately 20% of total knee arthroplasty (TKA) patients are found to be dissatisfied or unsure of their satisfaction at 1-year post-surgery. This study attempted to predict 1-year post-surgery dissatisfied/unsure TKA patients with pre-surgery and surgical variables using logistic regression and machine learning methods., Methods: A retrospective analysis of patients who underwent primary TKA for osteoarthritis between 2012 and 2016 at a single institution was completed. Patients were split into satisfied and dissatisfied/unsure groups. Potential predictor variables included the following: demographic information, patella re-surfaced, posterior collateral ligament sacrificed, and subscales from the Knee Society Knee Scoring System, the Knee Society Clinical Rating System, the Western Ontario and McMaster Universities Osteoarthritis Index, and the 12-Item Short Form Health Survey version 2. Logistic regression and 6 different machine learning methods were used to create prediction models. Model performance was evaluated using discrimination (AUC [area under the receiver operating characteristic curve]) and calibration (Brier score, Cox intercept, and Cox slope) metrics., Results: There were 1432 eligible patients included in the analysis, 313 were considered to be dissatisfied/unsure. When evaluating discrimination, the logistic regression (AUC = 0.736) and extreme gradient boosted tree (AUC = 0.713) models performed best. When evaluating calibration, the logistic regression (Brier score = 0.141, Cox intercept = 0.241, and Cox slope = 1.31) and gradient boosted tree (Brier score = 0.149, Cox intercept = 0.054, and Cox slope = 1.158) models performed best., Conclusion: The models developed in this study do not perform well enough as discriminatory tools to be used in a clinical setting. Further work needs to be done to improve the performance of pre-surgery TKA dissatisfaction prediction models., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Approximately 20% of patients are dissatisfied with their total knee arthroplasty (TKA) at 1-year post-surgery. Met expectations have been found by some to significantly predict satisfaction. The role of met expectations in determining patient satisfaction has not been exhaustively explored. The primary aim of this study is to evaluate if met expectations moderate the relationship between pain and function variables and satisfaction., Methods: Patients who underwent primary TKA for osteoarthritis were included in the study (n = 304). Patient-reported outcomes at pre-surgery and 1-year post-surgery were collected. The Knee Society Score (KSS) satisfaction subscale was used as the dependent variable. Candidate independent variables included the following: demographics, KSS, Knee injury and Osteoarthritis Outcome Score (KOOS), 12-Item Short Form Health Survey (SF-12), Hospital Anxiety and Depression Scale, Pain Catastrophizing Scale, Self-Administered Comorbidity Questionnaire, and University of California Los Angeles activity score. Separate linear regression models were created to test interactions for KSS met expectations with pain and KSS met expectations with function., Results: Significant predictors of satisfaction were KSS symptoms (pain), KOOS activities of daily living (function), KSS met expectations, KOOS pre-surgery activities of daily living, body mass index, and SF-12 general health. A significant interaction between met expectations and pain was found (P = .043) and the met expectations and function interaction approached significance (P = .086). For both interactions, as met expectations increased, pain and function predicted satisfaction less strongly., Conclusion: Met expectations were found to moderate the relationship between pain and satisfaction. There may be more value in improving pain for patients with low met expectations., Level of Evidence: Level IV., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: The escalating socioeconomic burden of knee osteoarthritis (OA) underscores the need for innovative strategies to reduce wait times for total knee arthroplasty (TKA). The purpose of this study was to evaluate resource use, costs and health-related quality of life (HRQoL) across the continuum of care for patients with knee OA., Methods: This was a prospective study of 383 patients recruited from a high-volume teaching hospital at different stages of care (referral, consultation and presurgery). Outcomes included health care resource use; costs captured from the health care payer, private sector and societal perspectives; HRQoL measured using the Western Ontario and McMaster Universities Osteoarthritis Index, the 12-Item Short Form Health Survey, and EuroQoL 5-Dimension 5-Level tool; wait times; and the proportion of referrals deemed suitable candidates for surgery., Results: The most commonly used conservative treatments were pharmacotherapy, exercise and lifestyle modification. Forty percent of patients referred for TKA were deemed not to be suitable candidates for surgery. The greatest proportion of costs was borne by the patient or private insurer; a small proportion was borne by the public payer. Across all stages of care, more than 60% of the total costs was attributed to productivity losses. HRQoL remained relatively stable throughout the waiting period (mean wait time from referral to TKA 13.2 mo) but improved postoperatively., Conclusion: The suboptimal primary care management of knee OA calls for the development of innovative models of care. This study may provide valuable guidance on the design and implementation of a new online educational platform to improve referral efficiency and expedite wait times for TKA., Competing Interests: S. MacDonald reports receiving personal fees from DePuy Synthes and holding stock or stock options from Hip Innovations Technology, JointVue, CurvaFix, Parvizi Surgical Innovation, Smith & Nephew and Stryker, outside the submitted work. No other competing interests were declared., (© 2021 CMA Joule Inc. or its licensors.)

Background: Total knee arthroplasty (TKA) is a common treatment for end-stage knee osteoarthritis but is associated with increased complication rates compared with unicompartmental knee arthroplasty (UKA). UKA offers better functional outcomes but is associated with a higher risk of revision. The purpose of this study was to apply good-practice, stated-preference methods to quantify patient preferences for benefit-risk tradeoffs associated with arthroplasty treatments for end-stage knee osteoarthritis., Methods: A discrete-choice experiment was developed with the following attributes: chance of complications, functional ability, awareness of the knee implant, and chance of needing another operation within 10 years. Patients included those aged 40 to 80 years with knee osteoarthritis. A pivot design filtered respondents into 1 of 2 surveys on the basis of self-reported functional ability (good compared with fair or poor) as measured by the Oxford Knee Score. Treatment-preference data were collected, and relative attribute-importance weights were estimated., Results: Two hundred and fifty-eight completed survey instruments from 92 males and 164 females were analyzed, with 72 respondents in the good-function cohort and 186 in the fair/poor-function cohort. Patients placed the greatest value or relative importance on serious complications and rates of revision in both cohorts. Preference weights did not vary between cohorts for any attribute. In the good-function cohort, 42% of respondents chose TKA and 58% chose UKA. In the fair/poor-function cohort, 54% chose TKA and 46% chose UKA., Conclusions: Patient preferences for various treatment attributes varied among patients in a knee osteoarthritis population. Complication and revision rates were the most important factors to patients, suggesting that physicians should focus on these areas when discussing treatments. The proportion of patients who chose UKA suggests that the current trend of increased UKA utilization is aligned with patient preferences., Clinical Relevance: Systematic elicitation of patient preferences for knee arthroplasty procedures, which lays out evidence-based risks and benefits of different treatments, indicates a larger subset of the knee osteoarthritis population may prefer UKA than would be suggested by the current rates of utilization of the procedure. Arthroplasty treatment should align with patient preferences and eligibility criteria to better deliver patient-centered care.

Background: Lateral approaches to total knee arthroplasty (TKA) provide good surgical exposure and may provide greater ease of soft tissue balancing in patients with a valgus deformity; however, little is known about the versatility in non-valgus knees. The present study evaluated if a lateral subvastus approach can achieve adequate surgical exposure while maintaining less soft tissue damage compared with the medial parapatellar approach in knees without any significant deformity., Methods: Using paired fresh-frozen cadaveric knees, the present study provides the first specimen-matched, side-by-side comparison of the lateral subvastus approach to the standard medial parapatellar approach to TKA. Ten knees were selected to undergo a lateral subvastus approach; the contralateral knee had a medial parapatellar approach as control. Incision length, surgical exposure and iatrogenic soft tissue damage were compared between the two approaches., Results: The lateral subvastus approach was successfully performed using an incision length that was not different from that used in the medial parapatellar approach (p > 0.05). The resultant surgical exposure was comparable between approaches (p > 0.05). The risk of the approach included tearing of the vastus lateralis fibers, and/or abrasion of the iliotibial tract/patellar ligament., Conclusions: The lateral subvastus approach to TKA provided a comparable method to the standard medial parapatellar approach. Despite adequate exposure, the approach did risk soft tissue injury. Caution needs to be exercised to reduce the risk of iatrogenic injury to the vastus lateralis and surrounding ligaments. The successful implementation in this cadaveric study substantiates the need for further consideration of this approach in clinical practice., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: There is controversy regarding the superiority of posterior-stabilizing (PS) total knee arthroplasty (TKA) and cruciate-retaining (CR) TKA. Substantial work has made comparisons between PS and CR TKA at follow-ups of less than 5 years. It was the goal of the present study to compare the kinematics at greater than 5 years postoperatively between CR and PS TKA, with a secondary goal of comparing patient function., Methods: A total of 42 knees were investigated, with equal representation in the PS and CR TKA groups. Patients underwent radiostereometric analysis imaging at 0°, 20°, 40°, 60° 80°, and 100° of flexion. Contact position, magnitude of excursion, and condylar separation on each condyle were measured. A Timed-Up-and-Go functional test was also performed by patients, with the total test time being measured. Preoperative and postoperative clinical outcome scores were also collected., Results: There were differences in contact position on both the medial and lateral condyles at multiple angles of flexion (P < .05). There was no difference (P = .89) in medial excursion; however, PS TKA had greater lateral excursion than CR TKA (P < .01). No difference (P > .99) was found in frequency of condylar separation. PS TKA was associated with faster (P = .03) total Timed-Up-and-Go test times. There were no differences in clinical outcome scores between the groups preoperatively or postoperatively., Conclusion: We found kinematic and functional differences that favor PS TKA. Our results suggest posterior cruciate ligament insufficiency in CR TKA, indicating that perhaps the cam/post systems in PS TKA better maintain knee kinematics and function long term., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Orthopedic surgeons recognize patient expectations of total knee arthroplasty (TKA) can be managed through education. E-learning is the application of educational technology. The objective of this study was to evaluate whether an e-learning tool could affect whether patients' expectations were met and they were satisfied 1 year following TKA., Methods: Patients with osteoarthritis from the London Health Sciences Centre, Canada, were randomly assigned to either a control group (n = 207) receiving standard patient education or an intervention group (n = 209) using the e-learning tool in addition to the standard. We used a web-based system with permuted block sizes, stratified by surgeon and first or second TKA. Preoperative measures were completed following the patients' preadmission clinic visit. Postoperative patient-reported outcome measures were completed at 6 weeks, 3 months, and 1 year after TKA. One year after TKA, risk difference was used to determine between-group differences for patient satisfaction and expectations being met., Results: One year postoperatively, the risk that expectations of patients were not met was 21.8% in the control group and 21.4% in the intervention group for an adjusted risk difference of 1.3% (95% confidence interval, -7.8% to 10.4%, P = .78). The proportion of patients satisfied with their TKA at 1 year postoperative was 78.6% in the intervention and 78.2% in the control groups., Conclusion: There was no between-group difference at 1 year between intervention and control groups for either the risk that expectations of patients were not met or the proportion of patients who were dissatisfied with their TKA., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: To examine implant migration and articular behavior of primary total knee arthroplasty (TKA) at 10 years after index surgery and correlate to implant alignment., Methods: Thirty-five patients underwent a cemented posterior stabilized total knee arthroplasty with a surgical objective of neutral alignment and were enrolled in a long-term radiostereometric analysis (RSA) study. At 10 years after surgery, patients were analyzed for implant migration using RSA as well as radiographic assessment of articular behavior at four positions of knee flexion. Implant position and alignment was measured on full-length radiographs. Patient demographics and reported outcomes were also collected., Results: No difference between patient demographics or patient-reported outcomes were found. When categorized into neutral and varus groupings, no difference in migration was present. If alignment was considered as a continuous variable, there was no correlation between overall leg alignment and migration, however, migration increased with an increasing varus tibial alignment. Although contact location did not differ between neutral and varus groups through a range of motion, condylar liftoff was much more common in the varus group, of which all were lateral liftoff., Conclusions: Increased tibial varus results in increased implant migration. Overall varus limb alignment is correlated with isolated lateral compartment liftoff, and liftoff occurs more commonly than in neutral aligned knees. The increased migration and liftoff raise concerns about the longevity of malaligned total knee replacements. If a goal of overall varus limb alignment is desired for TKA, the tibia should remain neutral., Level of Evidence: Level III.

Purpose: The role of neutral alignment in total knee arthroplasty (TKA) on short- and long-term outcomes has become controversial. Based on the concept of constitutional varus, it has been suggested that under-correction in TKA in a varus osteoarthritis (OA) population might lead to better clinical outcomes. However, it is still unknown what the relationship between constitutional varus and the development of end-stage OA is. The goal of this study was to analyse the contribution of constitutional varus in a medial OA population and to define a correlation between the constitutional alignment and end-stage varus OA., Methods: Based on full-length radiographs, corrected for the intra-articular deformity of the knee, of 315 patients with unilateral end-stage medial OA of the knee (Charnley type A), a correlation in the coronal plane was made between medial end-stage OA and the contralateral non-arthritic side., Results: With increasing varus alignment in the arthritic limb, the physiologic limb alignment also became more varus. The proportion of constitutional varus rose with increasing overall alignment and was found to be continuous for males. Constitutional varus was three times higher in men when the overall arthritic alignment was greater more than 6° varus., Conclusion: Constitutional varus significantly contributes to varus osteoarthritis and was found to be higher than in the general population., Level of Evidence: III.

The purpose of this study was to compare clinical outcomes of total knee arthroplasty (TKA) after manipulation under anaesthesia (MUA) for post-operative stiffness with a matched cohort of TKA patients who did not requre MUA. In total 72 patients (mean age 59.8 years, 42 to 83) who underwent MUA following TKA were identified from our prospective database and compared with a matched cohort of patients who had undergone TKA without subsequent MUA. Patients were evaluated for range of movement (ROM) and clinical outcome scores (Western Ontario and McMaster Universities Arthritis Index, Short-Form Health Survey, and Knee Society Clinical Rating System) at a mean follow-up of 36.4 months (12 to 120). MUA took place at a mean of nine weeks (5 to 18) after TKA. In patients who required MUA, mean flexion deformity improved from 10° (0° to 25°) to 4.4° (0° to 15°) (p < 0.001), and mean range of flexion improved from 79.8° (65° to 95°) to 116° (80° to 130°) (p < 0.001). There were no statistically significant differences in ROM or functional outcome scores at three months, one year, or two years between those who required MUA and those who did not. There were no complications associated with manipulation. At most recent follow-up, patients requiring MUA achieved equivalent ROM and clinical outcome scores when compared with a matched control group. While other studies have focused on ROM after manipulation, the current study adds to current literature by supplementing this with functional outcome scores., (©2015 The British Editorial Society of Bone & Joint Surgery.)

Current discussion exists whether to position a total knee arthroplasty (TKA) in slight undercorrection in varus osteoarthritis. The goal of this study was to analyse the effect of wear and lateral lift-off in primary TKA on coronal plane alignment and the implication to future constrained revision TKA. Seventy-six retrieved tibial inserts were analysed for the ratio of wear (RW), lateral lift-off and implications for future constrained revision surgery according to the coronal plane alignment. The RW significantly affects the coronal plane alignment in TKA. Progressive wear and lateral lift-off were seen with progressive varus alignment. However, there was no difference in constrained revision between mild varus and moderate varus aligned TKAs., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The purpose of this study was to assess the feasibility, effectiveness and costs of a web-based follow-up compared to in-person assessment following primary total hip or total knee arthroplasty. Patients who were at least 12 months postoperative were randomized to follow-up method. We excluded patients who had revision surgery, osteolysis, complications or identified radiographic issues. 229 patients (118 Web, 111 in-person) completed the study. There were no patients who had an issue missed by the web-based follow-up. Patients in the web-based group travelled less (28.2km vs 103.7km, (P<0.01)), had lower associated costs ($10.45 vs $21.36, (P<0.01)) and took less time to complete (121.7min web vs 228.7min usual). Web-based follow-up is a feasible, clinically effective alternative with lower associated costs than in-person clinic assessment., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The purpose of this study was to determine the fate of the remaining hip(s) and knee(s) following an initial total hip or knee arthroplasty in 5352 patients with idiopathic osteoarthritis who were followed for a minimum ten years (mean 17.8 ± 5.7 years). Following an initial primary TKA, 46.0% of patients had a contralateral TKA, 2.3% had an ipsilateral THA and 1.3% had a contralateral THA. Following an initial primary THA, 30.5% of patients had a contralateral THA, 6.8% had an ipsilateral TKA and 2.9% had a contralateral TKA. Cox regression analysis demonstrated that BMI was the sole risk factor for a second THA, but both age less than sixty years and a higher BMI were significant factors for patients requiring an additional primary TKA., (Copyright © 2013. Published by Elsevier Inc.)

A total of 6275 consecutive TKA patients were divided into three groups based on their age: <55, 55-70 and >70 years. There was a statistically significant difference in the change in WOMAC score (32 vs 31 vs 26, P<0.001) and Knee Society Score (78.9 vs 76.0 vs 69.0, P<0.001) favoring the younger populations. However, the revision rate was higher in the younger patients with a Kaplan-Meier survivorship at 5 years of 95.5%, 97.2% and 98.1% and at 10 years of 92.2%, 95.9% and 97.6%. Infection was the most frequent cause for failure in all groups although aseptic loosening and instability accounted for the increased revision rate in the younger patients. Younger patients may experience slightly better clinical outcomes following TKA but lower survivorship, when compared to older patient populations., (© 2013 Elsevier Inc. All rights reserved.)

Objective: Little is known about the relationships among pain, function, psychological variables like perceived helplessness and emotional health, and patient satisfaction in people with revision knee replacement surgery. We hypothesized that pain and function would have a direct association with satisfaction as well as an indirect association through patient perceptions of helplessness and emotional health., Design: This longitudinal study included 145 participants undergoing revision knee replacement surgery. Demographic data and expectation of benefit from surgery were recorded prior to surgery. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Arthritis Helplessness Scale (AHS) and the Mental Component Scale (MCS) of the SF-36 (emotional health) were collected prior to and 2 years post-surgery. Satisfaction was recorded 2 years post-surgery. Regression analyses were conducted to test for mediation effects of helplessness and MCS., Results: Participants were on average 69 years old and 54% were women. Participants were satisfied with the results of the surgery (mean ± standard deviation (SD) = 70.42 ± 31.46). Less pain and functional disability were associated with increased patient satisfaction and, the effect of pain or function was also mediated through helplessness whereby more pain and disability were associated with perceptions of helplessness and helplessness was associated with lower satisfaction. MCS did not mediate the relationship of pain and function with satisfaction., Conclusion: Helplessness plays an important role in understanding patient satisfaction. Interventions aimed at improving patient outcome should target not only pain and function but also should address strategies to support people in managing following knee revision surgery to maximize satisfaction with outcome., (Copyright © 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Obesity is an epidemic across both the developed and developing nations that is possibly the most important current public health factor affecting the morbidity and mortality of the global population. Obese patients have the potential to pose several challenges for arthroplasty surgeons from the standpoint of the influence obesity has on osteoarthritic symptoms, their peri-operative medical management, the increased intra-operative technical demands on the surgeon, the intra- and post-operative complications, the long term outcomes of total hip and knee arthroplasty. Also, there is no consensus on the role the arthroplasty surgeon should have in facilitating weight loss for these patients, nor whether obesity should affect the access to arthroplasty procedures.

Background: TKA and unicompartmental knee arthroplasty (UKA) are both utilized to treat unicompartmental knee arthrosis. While some surgeons assume UKA provides better function than TKA, this assumption is based on greater final outcome scores rather than on change in scores and many patients with UKA have higher preoperative scores., Questions/purposes: We therefore asked whether TKA would demonstrate (1) better change in clinical outcome scores from preoperative to postoperative states and (2) better survivorship than UKA., Methods: We evaluated 4087 patients with 5606 TKAs and 179 patients with 279 UKAs performed between 1978 and 2009. Patients with TKA were older and heavier than patients with UKA (mean age, 68 versus 66 years; mean BMI, 32 versus 29). We compared preoperative, latest postoperative, and change in Knee Society Clinical Rating System (KSCRS), SF-12, and WOMAC scores. Minimum followup was 2 years (UKA: mean, 7 years; range, 2.0-23 years; TKA: mean, 6.5 years; range, 2.0-33 years). Preoperative outcome measure scores (WOMAC, SF-12, KSCRS) were higher in the UKA group., Results: Patients with UKA had higher postoperative KSCRS and SF-12 mental scores. Changes in score for all WOMAC domains were similar between groups. Total KSCRS changes in score were similar between groups, although patients with TKA had higher knee scores (49 versus 43) but lower function scores than UKA (21 versus 26). Cumulative revision rate was higher for UKA than for TKA (13% versus 7%). Kaplan-Meier survivorship at 5 and 10 years was 95% and 90%, respectively, for UKA and 98% and 95%, respectively, for TKA., Conclusions: While patients with UKA had higher pre- and postoperative scores than patients with TKA, the changes in scores were similar in both groups and survival appeared higher in patients with TKA.

Unlabelled: The range of motion after TKA depends on many patient, surgical technique, and implant factors. Recently, high-flexion designs have been introduced as a means of ensuring or gaining flexion after TKA. We therefore evaluated factors affecting postoperative flexion to determine whether implant design influences longterm flexion. We prospectively collected data on patients receiving a primary Genesis II total knee replacement with a minimum of 1-year followup (mean, 5.4 years; range, 1-13 years). We recorded pre- and postoperative outcome measures, patient demographics, and implant design (cruciate retaining [CR, n = 160], posterior stabilized [PS, n = 1177], high-flex posterior stabilized [HF-PS, n = 197]). Backward stepwise linear regression modeling identified the following factors affecting postoperative flexion: preoperative flexion, gender, body mass index, and implant design. Independent of gender, body mass index, and preoperative flexion, patients who received a HF-PS and PS design implant had a mean of 8 degrees and 5 degrees more flexion, respectively, than those who received a CR implant. Patients with low flexion preoperatively (<100 degrees) were more likely to gain flexion, whereas those with high flexion preoperatively (>120 degrees) were most likely to maintain or lose flexion postoperatively. Controlling for implant design, patients with high flexion preoperatively (>120 degrees) were more likely to gain flexion with the HF-PS design implant (HF-PS = 32.0%; PS = 15.1%; CR = 4.5%)., Level of Evidence: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Unlabelled: Medial unicompartmental arthroplasties (UKA) are available with mobile- and fixed-bearing designs, with the advantages of one bearing over another unproven. We questioned whether the bearing design influenced clinical outcome, survivorship, the reason for revision, or the timing of failures. We retrospectively reviewed 179 patients (229 knees) who had medial unicompartmental knee arthroplasties between 1990 and 2007; of these 79 knees had a mobile-bearing design and 150 knees a fixed-bearing design. Patients with mobile-bearing UKA had a minimum followup of 1 year (mean, 3.6 years; range, 1-11.3 years); those with fixed-bearing UKA a minimum followup of 1 year (mean, 8.1 years; range, 1-17.8 years). Patients were evaluated with clinical outcome scores and radiographically using the Knee Society rating system. Seven of 79 (9%) mobile-bearing knees underwent revision at a mean of 2.6 years, and 22 of 150 (15%) fixed-bearing knees underwent revision at a mean of 6.9 years. The 5-year cumulative survival rates were 88% (SE +/- 0.47, 95% CI 0.7229-1) and 96% (SE +/- 0.16, 95% CI 0.93-0.9979) for the mobile- and fixed-bearing designs respectively using the endpoint of revision surgery. We observed no differences in the indications or complexity of revision surgery between the groups and none in midterm survivorship., Level of Evidence: Level III, comparative study. See Guidelines for Authors for a complete description of levels of evidence.

Unlabelled: Gender-specific total knee replacement design is a recent and debated topic. We determined the survivorship and clinical outcomes of a large primary total knee arthroplasty cohort, specifically assessing any differences between gender groups. A consecutive cohort of 3817 patients with 5279 primary total knee replacements (3100 female, 2179 male) with a minimum of 2 years followup were evaluated. Preoperative, latest, and change in clinical outcome scores (WOMAC, SF-12, KSCRS) were compared. While men had higher raw scores preoperatively, women had greater improvement in all WOMAC domains including pain (29.87 versus 27.3), joint stiffness (26.78 versus 24.26), function (27.21 versus 23.09), and total scores (28.35 versus 25.09). There were no gender differences in improvements of the SF-12 physical scores. Men had greater improvement in Knee Society function (22.1 versus 18.63) and total scores (70.01 versus 65.42), but not the Knee Society knee score (47.83 versus 46.64). Revision rates were 10.2% for men and 8% for women. Women demonstrated greater implant survivorship, greater improvement in WOMAC scores, equal improvements in SF-12 scores, and less improvement in only the Knee Society function and total scores. The data refute the hypothesis of inferior clinical outcome for women following total knee arthroplasty when using standard components., Level of Evidence: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Five hundred fifty patients who underwent primary total knee arthroplasty between 1987 and 2004 with a primary diagnosis of osteoarthritis and 1-year outcome data (Western Ontario and McMaster Osteoarthritis Index [WOMAC]) were evaluated. Patients were stratified into body mass index categories based on the World Health Organization classification of obesity. Patients were dichotomized into a class III morbidly obese group and a non-morbidly obese group. Independent t test and multivariable linear regression were used to determine if a difference existed in the 1-year WOMAC outcome between morbidly obese patients and all other patients. Although 1-year outcomes were worse for morbidly obese patients (P < .05), they showed greater improvement in function compared with non-morbidly obese patients. Morbid obesity does not affect 1-year outcomes in patients who have had a total knee arthroplasty.