Ulnar Forearm Osteocutaneous Flap Harvesting Using Kapandji Procedure for Pre-Existing Complicated Fibular Flap on Mandible Reconstruction—Cadaveric and Clinical Study

Abstract

It is not uncommon that after using a fibular flap for lower gum cancer reconstruction, nonunion, chronic osteomyelitis, or fibular bone exposure occurs, which requires a composite bone and soft tissue reconstruction. Radial forearm osteocutaneous flap possesses the risk of stress fracture. Ulnar forearm osteocutaneous flap can be another option for small bone defect reconstruction. Six patients who had undergone fibular flap for mandible reconstructions and sustained either bone exposure (3 patients), chronic osteomyelitis (1 patient), malocclusion (1 patient), or osteoradionecrosis (1 patient) underwent ulnar forearm osteocutaneous flap with 3-cm ulnar bone for touch-up procedure. The distal radioulnar joints were fused with a screw. Six ulnar forearm osteocutaneous flap dissections were also performed on 4 fresh frozen cadavers to clarify the anatomic distribution of the distal ulnar artery. All 6 ulnar forearm osteocutaneous flaps survived with one re-exploration for venous occlusion. All presented bone union. Comparable to the clinical dissection, the cadaveric distal ulnar artery demonstrates a periosteal branch that runs between the proper ulnar nerve and dorsal sensory nerve. This periosteal branch comes out of an ulnar artery approximately 3 cm proximal to the wrist joint. Ulnar forearm osteocutaneous flap can provide a secondary flap of wide skin paddle and small segment bone for specific mandibular defect after a fibular flap transfer.