Trochlear cartilage status at second-look arthroscopy predicts 2-year outcomes after around-knee osteotomy, especially in older patients.

Purpose: To investigate whether trochlear surface cartilage degeneration of the patellofemoral joint, assessed by second-look arthroscopy after around-knee osteotomy (AKO), affects postoperative patient-reported outcomes and to examine the influence of patient age on this relationship. Methods: This retrospective cohort study included 331 patients who underwent AKO for varus knee deformity between November 2016 and June 2022. Second-look arthroscopy was performed approximately 1 year postoperatively, and patients were classified according to femoral trochlear cartilage status at second-look arthroscopy. International Cartilage Repair Society (ICRS) grades 0-2 were defined as nearly normal and ICRS Grades 3-4 as abnormal for the purpose of this study. The primary outcomes were the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Lysholm score at 2 years. Overlap weighting based on propensity score was used to adjust for confounders. Results: Of 331 patients, 229 were classified as nearly normal and 102 as abnormal. The abnormal group was older (67.15 ± 8.27 vs. 64.63 ± 9.74 years; Conclusions: Trochlear cartilage degeneration observed at second-look arthroscopy after AKO is associated with poorer 2-year outcomes, particularly in older patients. These findings suggest that a favourable trochlear cartilage status at second-look is a meaningful prognostic indicator. Monitoring postoperative cartilage status-especially improvement or stability-may aid in identifying patients likely to achieve better recovery and inform age-specific treatment strategies. Level of Evidence: Level III.