Background and Aims: High tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are established surgical options for isolated medial compartment knee osteoarthritis. While both procedures yield satisfactory functional outcomes, differences in post-operative joint awareness remain incompletely defined. The forgotten joint score-12 (FJS-12) is a sensitive patient-reported outcome measure designed to assess joint awareness with minimal ceiling effect. The aim of this systematic review is to compare temporal trends in joint awareness, assessed using FJS-12, following HTO and UKA at different post-operative time points. Materials and Methods: A systematic review and limited meta-analysis were conducted according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. PubMed/MEDLINE, SCOPUS, EMBASE, and the Cochrane Library were searched for studies reporting FJS-12 outcomes following HTO and/or UKA for medial compartment osteoarthritis. Comparative clinical studies were included. Data extraction and risk-of-bias assessment using the Newcastle–Ottawa scale were performed independently by two reviewers. Mean differences (MD) in FJS-12 were pooled using a random-effects model. Results: Five retrospective comparative studies comprising 535 patients (286 UKA and 249 HTO) were included. UKA demonstrated significantly higher FJS-12 values during the early post-operative period (3–6 months), indicating lower joint awareness. However, by 12 months, this difference had narrowed down substantially. Pooled analysis at ≥2 years showed no statistically significant difference in FJS-12 between UKA and HTO (MD 2.39; 95% confidence intervals: −3.80–8.59; p = 0.45). Long-term follow-up beyond 10 years similarly demonstrated comparable joint awareness between these two procedures. Younger age and higher post-operative functional scores were consistent predictors of higher FJS-12. Conclusion: UKA is associated with lower joint awareness than HTO in the early post-operative period, particularly within the first 3–6 months after surgery. However, this early advantage diminishes over time, and by 2 years postoperatively and beyond, joint awareness assessed using the FJS-12 is comparable between the two procedures. These findings suggest that while UKA may facilitate faster perceptual adaptation in the short term, both HTO and UKA achieve similar levels of joint awareness in the mid- to long-term follow-up.
Tripathy et al. (2026) studied this question.