Meta-analysis and systematic review of the outcome of reparative strategies for the treatment of deep joint defects of the knee in adult patients

Introduction: Deep joint surface defects, affecting both full-depth articular cartilage and a substantial part of subchondral bone, remain a therapeutic challenge. If left untreated, they often lead to symptomatic osteoarthritic disease and joint failure. As new treatment strategies continue to emerge, it is essential to critically evaluate existing approaches. This study aims to compare the clinical outcomes and failure rates of various surgical strategies based on current literature. Methods: An analysis was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, focusing on clinical outcomes of treatments for deep osteochondral defects in the human knee. Studies from PubMed, Web of Science, and Embase were reviewed, selecting those with at least 10 adult patients and a minimum of 24-month follow-up. Quality appraisal was conducted using a modified Coleman score. Data extraction, pooling, and analysis were performed independently. The review assessed descriptive data, clinical outcomes, and failure rates of the included studies. Results: Seventeen prospective cohort studies or case series and 31 retrospective studies comprising a total of 1861 patients were eligible for analysis. Overall quality of the included studies was low. The most commonly used treatment strategies were the sandwich technique, osteochondral autografts, osteochondral allografts, and scaffolds, all showing moderate treatment effects on mid- to long-term, independent from the outcome measurement tool used. Failure rates in these treatment groups varied from 0% to 38.1%. Conclusions: Recommending one treatment over another for deep joint surface defects remains challenging due to various elements among which long-term sustainability is a critical one. Additional data from patient registries may offer a more representative view of daily clinical practice, which is valuable for tailoring treatments to individual patients.