Editorial Commentary: Shell Grafts Are Viable in "Select" Cases, and Improved Preservation Techniques May Help Us Improve Our Outcomes.

Patellofemoral joint chondral lesions can be challenging to treat with osteochondral allograft plugs because of the complex morphology and biomechanics of the patellofemoral joint Shell allografts replace the entirety of the damaged articular surface with a single osteochondral allograft piece (e.g., the entire trochlea or patella articular surface). Although technically demanding, shell grafts would allow for the treatment of bigger defects, correction of dysplasia, and for the treatment of uncontained lesions. However, shell allografts have historically shown inferior results than focal cylindrical grafts (bone plugs), with failure rates up to 38% based in the published literature. Although evidence exists demonstrating the efficacy of shell grafts in select cases, additional studies from multiple sources are required to support their continued use as well as determine the optimal graft-preservation techniques.