The Role of Osteotomy in the Patellofemoral Joint with Cartilage Surgery

Alignment and load distribution are critical factors to consider in the management of any chondral lesion of the knee. The aims of realignment osteotomies in the setting of patellofemoral (PF) chondral surgery are to reduce contact pressures in a global fashion and/or to redistribute load to a more favourable location within the patellofemoral joint (PFJ). Tibial tubercle (TT) osteotomy (TTO) with antero-medialisation has been the predominant distal realignment procedure used in this context; however, other osteotomies including direct anteriorisation, distalisation or medialisation have been described and utilised. Biomechanical data supports the efficacy of distal realignment procedures as a means to modulate PF contact pressures and kinematics. Despite this, there is a lack of high-quality comparative clinical trials and the specific indications for concomitant TTO with PF chondral surgery continue to be refined. The addition of a TTO to PF autologous chondrocyte implantation has been the most extensively investigated. Based on the available evidence, it is reasonable to consider a distal realignment procedure in conjunction with a PF chondral procedure in the setting of PF maltracking or malalignment and for lesions of the medial or central patellar with an increased TT-to-trochlear groove (TT-TG) distance. There may also be a role for distal realignment to reduce global contact pressures (such as pure TT anteriorisation) in conjunction with bipolar cartilage procedures in the absence of maltracking or malalignment; however, the evidence for this is less clear. The best indications for isolated TT antero-medialisation are focal distal or lateral patellar lesions with increased TT-TG distance. Relative amounts of medialisation and anteriorisation should be tailored to each patient. Optimisation of the biomechanical environment needs to be balanced against the surgical morbidity and risks associated with TTO.