Vascularized Osteochondral Grafts: Histologic Evaluation of Chondrocyte Viability with Viable Hyaline Nonfibrous Cartilage.

Vascularized osteochondral flaps are used for challenging arthroplasties of the upper extremity. Little has been described regarding the biological outcomes of these flaps, specifically regarding the structure of the cartilage. The authors present a case of a 31-year-old patient undergoing medial femoral trochlea flap for proximal scaphoid arthroplasty in the setting of proximal pole avascular necrosis. The patient sustained a fracture that was treated by a headless compression screw and demonstrated provisional radiographic healing, but at late follow-up he had new fragmentation of the proximal pole. The medial femoral trochlea flap that comprised the proximal pole of the reconstructed scaphoid was found to have viable chondrocytes and regularly oriented hyaline cartilage on pathologic analysis 1 year postoperatively. The patient initially had relief of wrist pain and return to work but ultimately developed intractable pain requiring scaphoidectomy and midcarpal arthrodesis. Despite the failure of the procedure, the presence of histologically normal cartilage and viable chondrocytes in a vascularized osteochondral flap offers encouragement that this technique may provide a durable long-term solution for articular reconstruction.