Overview of Randomized Controlled Trials in Total Knee Arthroplasty (47,675 Patients): What Have We Learnt?

BACKGROUND: The aim of this study is to provide an overview of randomized controlled trials (RCTs) in primary total knee arthroplasty summarizing the available high-quality evidence. METHODS: Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2019, Issue 3), Ovid MEDLINE, and Embase. We excluded nonrandomized trials, trials on unicompartmental knee arthroplasty or revision surgery, systematic reviews, and meta-analyses. Trials that met our inclusion criteria were assessed using a binary outcome measure of whether they reported statistically significant findings. These were then classified according to the intervention groups (surgical approach, tourniquet use, design, etc.). RESULTS: Four hundred and three RCTs met the inclusion criteria and were included. The total number of patients in those 403 RCTs was 47,675. Only 33 RCTs (8.2%) reported significant differences between the intervention and the control groups. The trials were grouped into surgical approach 34, tourniquet 31, minimally invasive surgery 13, patient specific instrumentation 30, knee design 37, fixation 27, mobile bearing 47, navigation 50, polyethylene 19, technique 27, patella resurfacing 26, drain 19, closure 16, and others 27 RCTs. CONCLUSION: For the vast majority of patients, a standard conventional total knee arthroplasty with a surgical approach familiar to the surgeon using standard well-established components, with or without tourniquet, without surgical drain leads to satisfactory long-term clinical outcomes.

myHip&Knee: Improving Patient Engagement and Self-Management Through Mobile Technology.

Given the increasing volume of hip and knee replacement surgery with reduced hospital stays and resources, we explored technology to address gaps in patient care and enhance self-management. The team at the Holland Orthopaedic and Arthritic Centre of Sunnybrook Health Sciences Centre, which performs a high volume of joint replacement surgery, partnered with patients and a health technology company to create a mobile app: myHip&Knee. The results to date demonstrate that the app improves patient experience and reduces follow-up calls to surgeons' offices, ultimately reducing demand on healthcare resources. Early engagement of privacy and legal services, close patient and family collaboration and a well-developed evaluation strategy represent critical steps to successful development.

A Phase IV Study of Thromboembolic and Bleeding Events Following Hip and Knee Arthroplasty Using Oral Factor Xa Inhibitor.

BACKGROUND: Multiple randomized controlled trials have documented the effectiveness of rivaroxaban in the prevention of venous thromboembolism up to 1-month following total joint arthroplasty. However, the effectiveness and safety of rivaroxaban in the real-world setting, outside of the strict protocols used by randomized clinical trials, are unknown. METHODS: This was a prospective, observational, noninterventional, phase IV study of 3914 consecutive patients who underwent total joint arthroplasty from June 2010 to December 2012. Patients were treated with rivaroxaban 10 mg by mouth daily starting postoperative day 1 and continued for 15 days. Participants were followed up in clinic at 6 weeks and contacted by telephone at 12 weeks. The primary outcome of interest was symptomatic venous thromboembolism; secondary outcomes included bleeding events, transfusion requirements, and death. RESULTS: The incidence of symptomatic deep venous thrombosis at 3 months was 0.5% (n = 18). Only 1 deep venous thrombosis event occurred within 7 days of surgery. The incidence of symptomatic pulmonary embolism (PE) at 3 months was 0.7% (n = 28). Thirteen PEs (46%) occurred within 7 days of surgery. The rate of major bleeding while on prophylaxis was 0.1%. Only 5% of patients received a blood transfusion. No deaths were attributed to thromboembolic events. CONCLUSION: This prospective, observational, phase IV study demonstrates that rivaroxaban appears to protect patients against symptomatic PE and is not associated with major bleeding events when used in a real-world setting as described.

Patient-reported compliance with thromboprophylaxis using an oral factor Xa inhibitor (rivaroxaban) following total hip and total knee arthroplasty.

This prospective study examines patient non-compliance (NC) for an oral factor Xa inhibitor (Rivaroxaban) when used as venous thromboembolic (VTE) prophylaxis following lower limb arthroplasty. A total of 3145 patients underwent surgery from May 2010 to December 2011. At 6 weeks patients completed an anonymous self-administered questionnaire. Postoperatively 2947 (94%, 2947/3145) received Rivaroxaban. 2824 (96%, 2824/2947) completed all in-hospital doses. Seven percent (203/2824) of patients did not attend the 6-week follow-up. Two thousand one hundred sixty-three (83%, 2163/2621) completed all prescribed doses, 98 (4%, 98/2621) were NC and 360 (14%, 360/2621) had incomplete data. Gender, age, body mass index and preoperative hemoglobin all correlated with NC (p < 0.05). Type and side of surgery did not correlate with compliance (p > 0.05). Patient-reported NC for Rivaroxaban is 4% which compares favorably to other VTE prophylaxis modalities.

Using outcome measure results to facilitate clinical decisions the first year after total hip arthroplasty.

STUDY DESIGN: Variable-occasion, repeated-measures design. OBJECTIVES: To model change in lower extremity functional status of patients 1 year after total hip arthroplasty (THA), using the Lower Extremity Functional Scale (LEFS) and the 6-minute walk test (6MWT), and, secondarily, to provide clinicians with useful data to guide practice. BACKGROUND: Given the prevalence of THA and current resource pressures, standardized outcome measures play an important role in providing physical therapists with objective knowledge about postoperative recovery and prognosis. METHODS: Seventy-five patients, with a mean age of 61 years and a diagnosis of hip osteoarthritis, consented to participate in the study. Assessments were conducted preoperatively and at multiple time points for up to 65 weeks postoperatively. Recovery was modeled using a nonlinear robust regression analysis for clustered data. The predictive ability of age, body mass index, and preoperative score was explored. RESULTS: Gender-based recovery curves were generated to depict the rate and amount of change in LEFS scores and 6MWT distances over the first year. Preoperative baseline 6MWT distance was the only covariate predictive of postarthroplasty 6MWT distances for both males and females. None of the covariates examined were significantly associated with postarthroplasty LEFS scores. CONCLUSION: Although there were variations in the recovery curves by measure, general patterns were noted. There was a rapid increase in both self-reported and physical performance measure scores for 12 to 15 weeks. Thereafter, we observed a slowing of recovery, with a plateau at 30 to 35 weeks for the 6MWT and later for the LEFS. These data can be used to make evidence-based decisions regarding prognosis and to guide the setting of measurable treatment goals. LEVEL OF EVIDENCE: Prognosis, level 1b.

Extensor mechanism reconstruction "Tubeplasty" in total knee arthroplasty with previous patellectomy: Surgical technique and clinical outcomes.

PURPOSE: to evaluate our consecutive series of tubeplasty and extensor mechanism reconstruction during knee arthroplasty in patients with previous patellectomy. METHODS: we describe our surgical technique and present a retrospective consecutive series of 4 patients with a minimum 6 months follow-up. Knee society score (KSS), clinical and radiographic outcomes were collected at final follow up. RESULTS: we included 4 patients (2 males/2 females) with average age 65.5 years (range 58-76). There were 2 primary and 2 revision knee arthroplasties. The follow up ranged from 0.5 to 13 years. All 4 patients regained function and satisfactory clinical outcomes with KSS score 84.7 (range 79-90). CONCLUSION: satisfactory clinical outcomes can be achieved with extensor mechanism reconstruction and tubeplasty in patients with previous patellectomy undergoing primary and revision knee arthroplasty. LEVEL OF EVIDENCE: IV.

Catastrophic Polyethylene Failure and Fractured Femoral Component in Modern Knee Arthroplasty Design: A Case Report.

CASE: We report a 67-year-old gentleman who presented with a painful unstable knee. He had undergone a successful total knee arthroplasty 12 years earlier and was highly functional. He presented with a 10-month history of mild pain, instability, and gait alteration. During revision surgery, there was a loss of bony support, and a fractured femoral component was identified. He required constrained revision components for reconstruction and made an uneventful recovery. CONCLUSIONS: Fractured femoral components are rare complications of modern primary total knee arthroplasty. Loss of bony support in critical areas of high loading will inevitably lead to catastrophic component failure.

Extensive Proximal Extensor Mechanism Realignment for Chronic Patella Dislocations in Revision Knee Arthroplasty: Surgical Technique.

Patella dislocation after primary or revision total knee arthroplasty (TKA) is a major challenge in revision surgery. In practice, the main reason for patella maltracking and instability following TKA is malrotation of the femoral and/or tibial components. A number of soft tissue procedures, once component malrotation is corrected, have been described including proximal realignment, quadricepsplasty and distal realignment of patellar tendon with tibial tubercle osteotomy. Here, we describe our modified surgical technique in managing chronically dislocated patellae in knee arthroplasty which comprises of extensive lateral releases, vastus medialis obliquus (VMO) advancement and soft tissue reconstruction of the extensor mechanism with accompanying three case presentations achieving satisfactory clinical outcomes.

Assessing recovery and establishing prognosis following total knee arthroplasty.

BACKGROUND AND PURPOSE: Information about expected rate of change after arthroplasty is critical for making prognostic decisions related to rehabilitation. The goals of this study were: (1) to describe the pattern of change in lower-extremity functional status of patients over a 1-year period after total knee arthroplasty (TKA) and (2) to describe the effect of preoperative functional status on change over time. SUBJECTS: Eighty-four patients (44 female, 40 male) with osteoarthritis, mean age of 66 years (SD=9), participated. METHODS: Repeated measurements for the Lower Extremity Functional Scale (LEFS) and the Six-Minute Walk Test (6MWT) were taken over a 1-year period. Data were plotted to examine the pattern of change over time. Different models of recovery were explored using nonlinear mixed-effects modeling that accounted for preoperative status and gender. RESULTS: Growth curves were generated that depict the rate and amount of change in LEFS scores and 6MWT distances up to 1 year following TKA. The curves account for preoperative status and gender differences across participants. DISCUSSION AND CONCLUSION: The greatest improvement occurred in the first 12 weeks after TKA. Slower improvement continued to occur from 12 weeks to 26 weeks after TKA, and little improvement occurred beyond 26 weeks after TKA. The findings can be used by physical therapists to make prognostic judgments related to the expected rate of improvement following TKA and the total amount of improvement that may be expected.

Modeling early recovery of physical function following hip and knee arthroplasty.

BACKGROUND: Information on early recovery after arthroplasty is needed to help benchmark progress and make appropriate decisions concerning patient rehabilitation needs. The purpose of this study was to model early recovery of physical function in patients undergoing total hip (THA) and knee (TKA) arthroplasty, using physical performance and self-report measures. METHODS: A sample of convenience of 152 subjects completed testing, of which 69 (mean age: 66.77 +/- 8.23 years) underwent THA and 83 (mean age: 60.25 +/- 11.19 years) TKA. Postoperatively, patients were treated using standardized care pathways and rehabilitation protocols. Using a repeated measures design, patients were assessed at multiple time points over the first four postoperative months. Outcome measures included the Lower Extremity Function Scale (LEFS), the physical function subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC PF), the 6 minute walk test (6 MWT), timed up and go test (TUG) and a timed stair test (ST). Average recovery curves for each of the measures were characterized using hierarchical linear modeling. Predictors of recovery were sequentially modeled after validation of the basic developmental models. RESULTS: Slopes of recovery were greater in the first 6 to 9 weeks with a second-degree polynomial growth term (weeks squared) providing a reasonable fit for the data over the study interval. Different patterns of recovery were observed between the self-report measures of physical function and the performance measures. In contrast to the models for the WOMAC PF and the LEFS, site of arthroplasty was a significant predictor (p = 0.001) in all of the physical performance measure models with the patients post TKA initially demonstrating higher function. Site of arthroplasty (p = 0.025) also predicted the rate of change for patients post THA and between 9 to 11 weeks after surgery, the THA group surpassed the function of the patients post TKA. CONCLUSION: Knowledge about the predicted growth curves will assist clinicians in referencing patient progress, and determining the critical time points for measuring change. The study has contributed further evidence to highlight the benefit of using physical performance measures to learn about the patients' actual level of disability.

Assessing stability and change of four performance measures: a longitudinal study evaluating outcome following total hip and knee arthroplasty.

BACKGROUND: Physical performance measures play an important role in the measurement of outcome in patients undergoing hip and knee arthroplasty. However, many of the commonly used measures lack information on their psychometric properties in this population. The purposes of this study were to examine the reliability and sensitivity to change of the six minute walk test (6MWT), timed up and go test (TUG), stair measure (ST), and a fast self-paced walk test (SPWT) in patients with hip or knee osteoarthritis (OA) who subsequently underwent total joint arthroplasty. METHODS: A sample of convenience of 150 eligible patients, part of an ongoing, larger observational study, was selected. This included 69 subjects who had a diagnosis of hip OA and 81 diagnosed with knee OA with an overall mean age of 63.7 +/- 10.7 years. Test-retest reliability, using Shrout and Fleiss Type 2,1 intraclass correlations (ICCs), was assessed preoperatively in a sub-sample of 21 patients at 3 time points during the waiting period prior to surgery. Error associated with the measures' scores and the minimal detectable change at the 90% confidence level was determined. A construct validation process was applied to evaluate the measures' abilities to detect deterioration and improvement at two different time points post-operatively. The standardized response mean (SRM) was used to quantify change for all measures for the two change intervals. Bootstrapping was used to estimate the 95% confidence intervals (CI) for the SRMs. RESULTS: The ICCs (95% CI) were as follows: 6MWT 0.94 (0.88,0.98), TUG 0.75 (0.51, 0.89), ST 0.90 (0.79, 0.96), and the SPWT 0.91 (0.81, 0.97). Standardized response means varied from .79 to 1.98, being greatest for the ST and 6MWT over the studied time intervals. CONCLUSIONS: The test-retest estimates of the 6MWT, ST, and the SPWT met the requisite standards for making decisions at the individual patient level. All measures were responsive to detecting deterioration and improvement in the early postoperative period.

Preoperative function and gender predict pattern of functional recovery after hip and knee arthroplasty.

Gender, preoperative function, and other variables were explored as predictors of recovery after total hip and knee arthroplasty. One hundred fifty-two subjects (63.8 +/- 10.2 years) were repeatedly assessed in the first 4 postoperative months. Average recovery curves for the Western Ontario and McMaster Universities Osteoarthritis Index, 6-minute walk test, and timed up and go test were characterized using hierarchical linear modeling. Recovery predictors were sequentially modeled after validation of the basic developmental models. Gender was a significant predictor (P < or= .003) of physical performance measure scores 1 week after surgery. Thereafter, men and women had similar rates of improvement. Preoperative score was a significant predictor (P < or= .001) in all models. Patients' and surgeons' expectations of outcome need to take preoperative function into account.

The relationship between self-report and performance-related measures: questioning the content validity of timed tests.

OBJECTIVE: To examine the determinants of the modest correlation between self-report and performance-related measures in patients with osteoarthritis of the hip or knee. METHODS: Measures included the Lower Extremity Functional Scale (LEFS), the self paced walk, timed up-and-go, and stair test. Each performance measure consisted of 3 domains: time, pain (visual analog scale), and exertion (Borg scale). Activity specificity was assessed by examining correlations between the LEFS with single activity and multiple activity time scores. Domain specificity was examined by comparing correlations between the LEFS and single and multiple domain scores. The impact of measurement error was considered. RESULTS: Increasing the number of activity time scores had no effect. Forming a composite performance score based on time, pain, and exertion substantially increased the correlation from 0.44 (composite timed score) to 0.59 (pooled domain and activity score) (P = 0.009). CONCLUSION: Performance scores based on time alone appear to inadequately represent the breadth of health concepts associated with functional status.

Classifying failed hip arthroplasty: generalizability of reliability and validity.

Interrater reliability and validity of a radiographic severity classification was evaluated in 81 patients having revision hip arthroplasty. Severity was rated separately on the femoral and acetabular sides using a five-level scale ranging from no significant loss of bone stock to uncontained loss of bone stock and discontinuity. Three academic orthopaedic surgeons rated preoperative anteroposterior radiographs taken within 6 weeks of surgery. Interrater reliability was 0.54 (weighted kappa) with 57% agreement on the acetabular side and 0.56 with 52% agreement on the femoral side. Rater to intraoperative findings agreed 45% of the time and weighted kappa was 0.41 on the acetabular side and agreed 38% of the time with weighted kappa of 0.39 on the femoral side. When radiographic and intraoperative ratings disagreed, 30% of the time no bony defect was found on the acetabular side. Fifty-eight percent of femoral radiographic ratings were upgraded intraoperatively. These results differ from previously reported results of high reliability from one institution with trained raters. A reliable and valid severity classification that is generalizable to multiple raters from different institutions is required to stratify patients for intervention studies, and to aid preoperative planning. Training in the classification system may improve generalizability.