Arthroscopic Technique to Treat Articular Cartilage Lesions in the Patellofemoral Joint

Cartilage lesions are frequent in routine knee arthroscopy (63%). Among these injuries, 11–23% are located in patella and 6–15% in the trochlea. Treatment of cartilage lesions in patellofemoral joint (PFJ) represents a challenge because of its complex access, high axial loading, and shearing forces. These factors explain the 7% of good results in the PFJ versus 90% in femoral condyles for autologous chondrocyte implantation (ACI). Microfracture (MF) as the first line of treatment has revealed limited hyaline-like cartilage formation in comparison to ACI. This fibrocartilage deteriorates with the time resulting in inferior biomechanical properties. Important issues that enhance the results of cartilage repair procedures in PFJ are associated with the restoration of the joint bal- ance as unloading/realigning techniques. In the literature, there is no description of any convenient arthroscopic technique for ACI. The reported techniques usually require to set up the patient in prone position to perform the arthroscopy making it difficult to treat associated knee malalignment or instability. Others are open techniques with more risk of morbidities, pain, and complications and longer recovery time. In this chapter, we will describe a novel all-arthroscopic technique to treat cartilage lesions in the patella that permits the correction and treatment of associated lesions in the same patient position. PFJ recommended Satisfactory results are reported in the treatment of isolated cartilage lesions in the patella with ACI (65%); however, when ACI was combined with unloading tibial tubercle osteotomy (AMZ), better results are found (85%) Clinically both microfracture and autologous chondrocyte implantation improve significantly over time after treatment. However, studies have demonstrated that quantitative assessment with T2-mapping in ACI is more similar to native cartilage than microfracture after 12 months.