The recovery trajectory of people undergoing treatment for knee articular cartilage damage: A systematic review and meta-analysis.

Abstract

Knowledge of recovery trajectories helps interpret studies, manage patient expectations and plan future trials. The purpose of this review was to summarise the recovery trajectory of participants undergoing the main treatments of full-thickness knee articular cartilage defects: microfracture, scaffold-based repair, cell expansion therapy or non-operative treatment. The search included Medline, Embase, Web of Science and the Cochrane Central Register of Controlled trials until April 2024. The primary outcome measure was International Knee Documentation Centre (IKDC) scores over time. Standardised mean change (SMC) with 95% confidence intervals (CI) was calculated to assess treatment response. 46 studies were included. There were no non-operative studies. All participants demonstrated an improvement in IKDC scores from baseline. Pooled SMC scores for all arms were: 0.67 (95% CI -0.01 to 1.34) at 3 months, 1.39 (95% CI 0.84-1.93) at 6 months, 1.85 (95% CI 1.40-2.30) at 12 months, 1.99 (95% CI 1.55-2.42) at 24 months, 2.27 (95% CI 1.15-3.40) at 36 months, and 2.31 (95% CI 1.67-2.95) at 60 months. Participants undergoing each procedure demonstrated a plateau in IKDC scores at 24 months. Scores were maintained at 60 months for microfracture and cell expansion therapy. No data existed beyond 36 months for scaffold-based repair. All arms showed an improvement in IKDC scores from baseline up until 24 months before plateauing. This was maintained at 60 months for those undergoing microfracture and cell expansion therapy. More long-term data are needed for scaffold-based repair.