Patellofemoral Cartilage Restoration: Indications, Techniques, and Outcomes

Patellofemoral cartilage restoration is an exciting field that encompasses both time-tested and emerging technologies. Surgical management of chondral or osteochondral lesions in the patellofemoral joint continues to evolve. Similarly, surgical success rates have improved over time; in large part due to the recognition that biological treatment of focal chondral/osteochondral lesions must be combined with correction of concomitant bony and soft-tissue abnormalities to optimize patient outcome.

This special focus section will highlight those procedures that may be utilized to treat a wide variety of patellofemoral disorders encountered by the treating surgeon. Drs. Farr and Nuelle will discuss internal fixation of osteochondral/chondral lesions associated with osteochondritis dissecans. Cell-based cartilage repair including particulated juvenile allograft cartilage and autologous chondrocytes implantation/matrix-induced autologous chondrocyte implantation will be discussed by Drs. Gomoll and Hinckel. Dr. Lattermann will report on the use of osteochondral allografts and other emerging osteochondral treatment options for the patellofemoral joint. Finally, Dr. Yanke and team will discuss indications, techniques, and outcomes of microfracture and OATS procedures for the patella and/or trochlea.

While this special section will focus on issues specific to surgical management of patellofemoral lesions, it is critical to recognize that the majority of patellofemoral chondral lesions can and should be treated nonoperatively. In most cases, surgery is reserved for patients who have failed conservative treatment and for patients who have optimized their “core to floor” strength and stability but have persistent painful dysfunction. Surgical success requires appropriate patient selection, choosing a technique that is suitable for the particular cartilage lesion(s), treatment of all bony and soft-tissue comorbidities, careful management of patient expectations, and extensive presurgical counseling to ensure compliance with the treatment regimen.

Each article in this special focus section will review the indications, techniques, and outcomes of cartilage restoration for the patellofemoral joint. Regarding indications and contraindications, authors will examine the lesion-specific (i.e., size, depth, location [patella, trochlea, bipolar], containment), joint-specific (i.e., early narrowing, early osteophytes, bony malalignment, soft-tissue imbalance), and patient-specific (i.e., age, body mass index, activity level) factors that may influence selection of one treatment option over another. Unlike the tibiofemoral joint, unique patellofemoral morphology and challenging biomechanics affect the typical “rules of engagement” for cartilage treatment. For example, procedures, such as microfracture, that may work for small, focal defects on the condyle have inferior outcomes on the patella. Complex patellofemoral joint geometry lends itself nicely to cell-based cartilage repair strategies. This same unique geometry adds technical challenges to osteochondral allograft transplantation. Conversely, osteochondral allograft may be an appealing option for cystic or osteochondral lesions and as a salvage for failed marrow stimulation or cell-based repair. Each section will provide a detailed description of the surgical techniques including pearls/pitfalls for success. Surgical outcomes will be reported for each technique to provide the reader with a comprehensive, evidence-based approach to the topic.

Overall, patellofemoral cartilage restoration can be challenging but highly rewarding work. Successful surgical management must begin with appropriate patient selection, comprehensive presurgical planning, meticulous surgical technique, and appropriate rehabilitation. Understanding and adhering to principles learned in this special focus section will help the surgeons to improve their outcome for this complex clinical problem.