Treatment of focal articular cartilage defects in the knee: a systematic review.

UNLABELLED: We asked whether autologous chondrocyte implantation or osteochondral autograft transfer yields better clinical outcomes compared with one another or with traditional abrasive techniques for treatment of isolated articular cartilage defects and whether lesion size influences this clinical outcome. We performed a literature search and identified five randomized, controlled trials and one prospective comparative trial evaluating these treatment techniques in 421 patients. The operative procedures included autologous chondrocyte implantation, osteochondral autograft transfer, matrix-induced autologous chondrocyte implantation, and microfracture. Minimum followup was 1 year (mean, 1.7 years; range, 1-3 years). All studies documented greater than 95% followup for clinical outcome measures. No technique consistently had superior results compared with the others. Outcomes for microfracture tended to be worse in larger lesions. All studies reported improvement in clinical outcome measures in all treatment groups when compared with preoperative assessment; however, no control (nonoperative) groups were used in any of the studies. A large prospective trial investigating these techniques with the addition of a control group would be the best way to definitively address the clinical questions. LEVEL OF EVIDENCE: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.