Clinical Outcomes of Unicompartmental Knee Arthroplasty in Patients with Full- Versus Partial-Thickness Cartilage Loss: A Systematic Review and Meta-Analysis

Abstract Bakground This meta-analysis was designed to compare postoperative patient-reported outcomes and reoperation rates following unicompartmental knee arthroplasty (UKA) between patients with full-thickness cartilage loss (FTCL) and partial-thickness cartilage loss (PTCL). Methods Multiple databases, including PubMed, Embase, Cochrane Library, and CNKI, were searched to identify studies comparing the Oxford Knee Score (OKS), American Knee Society (AKS) score, and reoperation rates between patients with FTCL and PTCL following UKA. Mean differences were calculated for continuous outcomes, and odds ratios were calculated for binary outcomes. Results A total of 613 UKAs (233 PTCL and 380 FTCL) from five retrospective cohort studies were included. Three studies compared OKSs after ≥2 years of follow-up. The mean difference in postoperative OKSs was significantly higher by 2.92 in the FTCL patients than in the PTCL patients (95% confidence interval [CI] −5.29 to −0.55; P = 0.02). The improvement in the OKS was significantly higher by 2.69 in the FTCL patients than in the PTCL patients (95 % CI −4.79 to −0.60; P = 0.01). AKS-knee and AKS-function scores were assessed in two studies at a mean follow-up time of >3.9 years. The mean difference in AKS-knee scores was similar between the groups (95%CI −9.14 to −3.34; P = 0.36), whereas the pooled mean difference in AKS-function scores was 5.63 higher in the FTCL group (95%CI −9.27 to −1.98; P = 0.002). All studies presented data on reoperation rates and showed that they were statistically higher in patients who underwent UKA with PTCL (OR 2.24, 95%CI 1.15–4.38, P = 0.02). Conclusions Compared with PTCL, FTCL achieved superior postoperative patient-reported outcomes and lower reoperation rates following UKA.