Mobile-bearing versus Medial-pivot Designs in Total Knee Arthroplasty: A Meta-analysis

Mobile-bearing (MB) and medial-pivot (MP) prostheses are the two popular designs used in total knee arthroplasty (TKA), yet their long-term outcomes remain controversial. This meta-analysis was conducted to determine whether there are any differences in outcomes between patients who receive these two prostheses in TKA.

We comprehensively searched electronic databases up to November 2024. Observational studies or randomized controlled trials reported postoperative outcomes, including radiographic results, functional score through the Knee Society Score (KSS), Western Ontario and McMaster Universities (WOMAC) score, and patient satisfaction. The results are presented in odd ratios (ORs) or mean differences with corresponding 95% confidence intervals (CIs).

In total, four studies were included, with 1069 patients and 1251 operated knees (632 MB TKAs and 619 MP TKAs). The mean age was 68.21 years old and the mean follow-up duration was from 5 to 11 years. Regarding patient satisfaction, the MB prostheses brought greater comfort to patients in the last follow-up than the MP group (OR = 3.19; 95%CI 1.92-5.30; p < 0.001). Additionally, there were no differences in the outcomes of functional scores, including the KSS (p = 0.34), WOMAC score (p = 0.16), and range of motion (ROM) (p = 0.36) between patients receiving the MB and MP prostheses.

Our meta-analysis of four studies highlighted the long-term outcomes of TKA between MB and MP designs. While KSS, WOMAC scores, and knee ROM showed no significant differences, patients with MB designs reported higher satisfaction levels compared with those with MP designs.