Comparison of High-Flexion and Conventional Implants in Total Knee Arthroplasty: A Meta-Analysis

Abstract

BackgroundThe purpose of this study was to evaluate whether high-flexion prostheses are superior to conventional prostheses after total knee arthroplasty (TKA).Material/MethodsWe searched the PubMed and Embase databases for randomized trials and cohort studies comparing high-flexion with conventional knee implants. The heterogeneity across studies was examined by I2 and Cochran’s Q-tests. Then the overall weighted mean differences of range of motion (ROM) and knee functional scores were evaluated.ResultsA total of 16 trials involving 2643 knees met our inclusion criteria. The results revealed that high-flexion implants were superior to conventional implants in the improvement of range of motion (weighted mean difference, 2.92; 95% CI, 1.63–4.22; p<0.0001). The clear advantage of high-flex PS (posterior stabilized) as well as high-flex CR (cruciate retaining) implants was found in ROM when compared to PS implants (2.73; 95% CI, 1.27–4.20; p=0.0003) and CR implants (3.24; 95% CI, 0.28–6.20; p=0.003), respectively. However, there was no difference in Knee Society Scores (0.42; 95% CI, −0.60–1.43; p=0.42), Knee Society function (0.37; 95% CI, −1.48–2.22; p=0.70) and Hospital for Special Surgery scores (0.26; 95% CI, −0.47–1.00; p=0.48) between high-flexion and conventional groups.ConclusionsThe current meta-analysis revealed that high-flexion implants were superior to conventional implants in the improvement of ROM but not in functional outcome scores.