This study was based on previous work completed by the same authors in 2004 which looked at the outcomes of autologous chondrocyte implantation and microfracture surgery at 2-year follow-up. This current study looks at outcomes at 5-year follow-up. 80 patients with a single chronic symptomatic cartilage defect on the femoral condyle were randomized to undergo one of two treatments. One group underwent an autologous chondrocyte implantation procedure while the other group underwent microfracture surgery. Results showed that clinical outcomes were comparable between the two groups. One-third of the patients showed radiographic signs of early osteoarthritis at the 5-year follow-up.