The vastus intermedius periosteal (VIP) flap: a novel flap for osteoinduction.

Periosteum's role in fracture healing is widely recognized, and its function in bone tissue engineering shows great potential. Here we introduce a novel periosteal free flap to be used as an abundant source of periosteum in the engineering and repair of bone. The descending branch of the lateral femoral circumflex vessels were isolated on 11 fresh human cadavers, preserving perforators to the vastus intermedius muscle. A cuff of vastus intermedius and approximately 75% of the circumference of the femoral periosteum were harvested from 6 cm proximal to the knee to 8 cm distal to the greater trochanter. Flap pedicle length and periosteal dimensions were measured. The pedicle arteries were injected with radiopaque dye, and radiographs were taken. A musculoperiosteal flap was elevated with visible descending perforators in each case. Mean flap surface area was 128 cm(2) (+/-99-143 cm(2)). Average pedicle length was 8 cm (+/-6-11 cm). Dye injection confirmed that the flaps blood supply was the descending branch of the lateral femoral circumflex artery. This anatomical study confirms the vascular supply of this large musculoperiosteal flap. Future work will test its efficacy as an osteoinductive agent in bone repair and tissue engineering in humans.