Osteochondral allograft transplantation of the knee: a review of indications,techniques, outcome and how to promote biology

Articular cartilage lesions of the knee in young and active patients can result in significant disability. Osteochondral allografts (OCAs) can be used to treat challenging articular lesions of the knee ≥2 cm², either as a primary or revision procedure. They have the advantage of restoring the articular surface with mature hyaline cartilage without any size limitations or donor site morbidity. Chondrocyte viability above 70% at the time of implantation is thought to be desirable, and consequently OCA implantation within the 28-day graft expiration date can result in logistical challenges. No randomized trials exist; however, excellent clinical outcomes have been reported, along with good long-term survivorship up to 20 years. Several factors can influence the outcome after OCA use, including patient selection, anatomical location, associated pathologies and several biological considerations. The purpose of this article is to review the latest evidence on treatment indications, graft storage and surgical techniques, biological considerations, patient outcomes and rehabilitation after surgery.