Medial Femoral Condyle Free Flap: A Systematic Review and Proportional Meta-analysis of Applications and Surgical Outcomes.

Background: Recalcitrant bone nonunion and osseous defect treatment is challenging and often requires vascularized bone transfer. The medial femoral condyle flap has become an increasingly popular option for reconstruction. The study aims at reviewing its different applications and synthesizing its surgical outcomes. Method: A systematic review including all studies assessing surgical outcomes of free medial femoral condyle flap for bone reconstruction in adults was conducted on January 31, 2023. Flap failure and postoperative complications were synthesized with a proportional meta-analysis. Results: Forty articles describing bony reconstruction in the head and neck, upper limb, and lower limb areas were selected. Indications ranged from bony nonunion and bone defects to avascular bone necrosis. Multiple flaps were raised as either pure periosteal, cortico-periosteal, cortico-cancellous-periosteal, or cortico-chondro-periosteal. A minority of composite flaps were reported. Overall failure rate was 1% [95% confidence interval (CI), 0.00-0.08] in head & neck applications, 4% in the lower limb (95% CI, 0.00-0.16), 2% in the upper limb (95% CI, 0.00-0.06), and 1% in articles analyzing various locations simultaneously (95% CI, 0.00-0.04). Overall donor site complication rate was 4% (95% CI, 0.01-0.06). Major reported complications were: femoral fractures (n = 3), superficial femoral artery injury (n = 1), medial collateral ligament injury (n = 1), and septic shock due to pace-maker colonization (n = 1). Conclusion: The medial femoral condyle flap is a versatile option for bone reconstruction with high success rates and low donor site morbidity.