Treatment of patellofemoral articular cartilage injuries with autologous chondrocyte implantation

Autologous chondrocyte implantation (ACI) has successfully been used to repair chondral injuries of the knee. Articular cartilage defects of the patella and trochlea represent a class of cartilage lesions of the knee that have recently been considered an increasing indication for treatment with ACI. These lesions often differ from condyle lesions, having a different etiology and coexisting pathologic conditions in the knee associated with them. Patellar and trochlear cartilage lesions are often associated with patellofemoral maltracking. To obtain good results with these cartilage injuries with ACI, it is essential to address the underlying maltracking issues. Additionally, the contours of the patellar and trochlear cartilage differ from that of the condyles, requiring a modification in the standard technique of periosteal attachment used with condylar lesions. Although results of treating trochlear lesions with ACI have shown good results, the initial reports of treating patellar lesions with ACI were diminished compared to condylar lesions. Recognizing and treating the coexisting pathologic conditions and carefully modifying the standard technique of periosteal attachment has resulted in improved results.