Surgical treatments of cartilage defects of the knee: Systematic review of randomised controlled trials

Background The aim of this systematic review was to identify high quality randomised controlled trials (RCTs) and to provide an update on the most appropriate surgical treatments for knee cartilage defects. Methods Two reviewers independently searched three databases for RCTs comparing at least two different treatment techniques for knee cartilage defects. The search strategy used terms mapped to relevant subject headings of MeSH terms. Strict inclusion and exclusion criteria were used to identify studies with patients aged between 18 and 55 years with articular cartilage defects sized between one and 15 cm2. Risk of bias was performed using a Coleman Methodology Score. Data extracted included patient demographics, defect characteristics, clinical outcomes, and failure rates. Results Ten articles were included (861 patients). Eight studies compared microfracture to other treatment; four to autologous chondrocyte implantation (ACI) or matrix-induced ACI (MACI); three to osteochondral autologous transplantation (OAT); and one to BST-Cargel. Two studies reported better results with OAT than with microfracture and one reported similar results. Two studies reported superior results with cartilage regenerative techniques than with microfracture, and two reported similar results. At 10 years significantly more failures occurred with microfracture compared to OAT and with OAT compared to ACI. Larger lesions (> 4.5 cm2) treated with cartilage regenerative techniques (ACI/MACI) had better outcomes than with microfracture. Conclusions Based on the evidence from this systematic review no single treatment can be recommended for the treatment of knee cartilage defects. This highlights the need for further RCTs, preferably patient-blinded, using an appropriate reference treatment or a placebo procedure.