Effectiveness of computer-assisted joint replacement (CA-TJR) compared to conventional TJR has been evaluated by a large body of literature. Systematic reviews provide a powerful, widely accepted, evidence-based approach to synthesize the evidence and derive conclusions, yet the strength of these conclusions is dependent on the quality of the review. Multiple systematic reviews compared CA-TJR and conventional TJR with conflicting results. We aimed to assess the quality of these reviews. We searched MEDLINE, EMBASE, the Cochrane, and Epistemonikos to identify SRs published through May 2017. Full-text articles that met inclusion criteria were retrieved and assessed independently by two reviewers. Evidence was qualitatively synthesized and summarized. Outcome measures were categorized into functional, radiological, and patient safety related. The corrected covered area (CCA) was calculated to assess the degree of overlap between SRs in analyzing the same primary studies. The AMSTAR 2, a valid and reliable tool, was applied to rate the confidence in the results of the SRs (Shea et al., 2017). AMSTAR-2 has 16 domains, of which 7 are critical (e.g., justification for excluding individual studies) and 9 are non-critical (e.g., not reporting conflict of interest for individual studies). Reviews are rated as high (no critical or non-critical flaws), moderate (only non-critical flaws), low (1 critical flaw) and critically low (more than one critical flaw). Disagreement between the 2 reviewers was resolved by discussion with the senior author to achieve consensus. We reported the quality ratings of these studies and the frequency of critical and non-critical flaws.Background
Methods
Patellofemoral arthroplasty (PFA) has experienced significant improvements in implant survivorship with second-generation designs. This has renewed interest in PFA as an alternative to total knee arthroplasty (TKA) for younger, active patients with isolated patellofemoral osteoarthritis (PF OA). The decision to select PFA over TKA balances the clinical benefits of sparing healthy knee compartments and ligaments against the risk of downstream conversion arthroplasty. We analyzed the cost-effectiveness of PFA versus TKA for the surgical management of isolated PF OA. We used a Markov transition-state model (Figure 1) to compare cost-effectiveness between PFA and TKA. Cohorts were aged 60 (base case) and 50 years. Lifetime costs (2015 USD), quality-adjusted life year (QALY) gains and incremental cost-effectiveness ratio (ICER) were calculated from a healthcare payer perspective. Annual revision rates were derived from the United Kingdom National Joint Registry and validated against the highest quality literature available. Deterministic and probabilistic sensitivity analysis was performed for all parameters against a $50,000/QALY willingness-to-pay. Results for the 50 year-old cohort were similar to those of the base case simulation.Purpose
Methods
Although conventional thinking and teaching have implicated weight and body mass index (BMI) in premature failure of total knee arthroplasty (TKA) there is scant evidence based confirmation of this belief. Furthermore, there is little knowledge regarding the precise effect of BMI on functional outcomes following TKA. We performed this study to assess the effect of weight on the longevity of TKA and on outcomes following TKA revision (TKAR). 186 consecutive subjects undergoing TKAR in a 17-center prospective cohort study, had data collected on weight (pounds), BMI and time elapsed between primary and revision surgery (T). The Physical Component Score (PCS) of the Short Form-36 (SF-36), the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index, and the Knee Society Score (KSS) were also collected preoperatively and at 6-month follow-up. Univariate, bivariate and multivariate statistical methods were used in the analysis. The mean BMI and weight were 31.8 (54% of subjects had a BMI >
30) and 200 pounds (range 107–350) respectively. The distribution of both measures of excessive weight was close to normal. Average time between primary and revision procedures (T) was 7.3 years (range 6 months to 27 years). Using linear regression, T significantly decreased as weight (BMI) increased. Mean SF-36 PCS, WOMAC and KSS-Function scores were significantly improved 6 months after revision surgery. However, BMI and, in particular, weight were predictive of worse physical functional outcomes. This study demonstrates the deleterious effect of weight on both the longevity of primary TKA as assessed at the time of revision and on functional outcomes following TKAR. Although further prospective data regarding this population is indicated, the current findings direct us towards better outcomes prediction for overweight patients and more effective counselling and appropriate management of these patients.
