Applications of the Vascularized Medial Femoral Condyle for Nonunion with Associated Bone Loss of the Foot: A Case Series

CATEGORY: Hindfoot, Midfoot/Forefoot INTRODUCTION/PURPOSE: Persistent nonunions with large bone defects continue to represent a challenging problem for foot and ankle surgeons. Vascularized corticocancellous grafts have been well described for various applications and represent a comprehensive solution to these difficult nonunion cases. We describe four cases of nonunions with concomitant large bony defects treated with a vascularized medial femoral condyle (VMFC). METHODS: We retrospectively identified four cases of VMFC flaps used for foot nonunions with large bone defects. Surgical indications included talonavicular nonunion with associated avascular necrosis of the navicular, talonavicular-cuneiform nonunion, navicular-cuneiform nonunion, and first metatarsophalangeal nonunion. All cases had large associated segmental bone defects. The average age at the time of surgery was 62-years-old. The average follow up was 2.6 years (1.5-5.0). One patient had a remote history of tobacco use. Another patient quit smoking pre-operatively and had normal nicotine metabolite levels at the time of surgery. There was one Type II diabetic. RESULTS: Two patients underwent staged reconstruction with placement of an antibiotic cement spacer, but intra-operative cultures were negative. No patient had a previous infection. The average graft dimensions were 3 x 2.25 x 1.5 cm. After obtaining adequate compression, all grafts were secured with bridge locking plates. The average time to weight bearing was 14.5 weeks. All patients had knee pain post-operatively that resolved with time. Two patients required reoperation. In one patient, the VMFC graft did not adequately fill the defect requiring supplement allograft. The VMFC-allograft interface went on to nonunion requiring tricortical iliac crest bone grafting. Another patient developed a split-thickness skin graft (STSG) infection requiring debridement and repeat STSG. There were no VMFC graft failures, and all patients went on to successful union. CONCLUSION: Vascularized medial femoral condyle autografts are a technically demanding solution to difficult nonunion cases with significant associated bone loss of the foot.