Use of Free Vascularized Fibular Graft for Congenital Ulnar Pseudarthrosis

Abstract

Congenital pseudarthrosis of the ulna may cause growth disturbance and progressive forearm deformity, leading to functional compromise of the upper extremity. Treatment is challenging, and surgical decision making must take into account three goals of treatment: bony healing, distal radioulnar joint (DRUJ) stability, and continued skeletal growth. Four cases of congenital ulnar pseudarthrosis treated with free vascularized fibular graft are presented here. In two cases, the vascularized fibular graft included the proximal fibular epiphysis to reconstruct the DRUJ and ulnocarpal joints. Average age of the four patients at time of vascularized fibular grafting was 10 years (range 3-16 years). Patients had undergone up to three previous failed operations. A step-cut osteotomy technique with rigid internal fixation was used in all patients. Donor-site distal tibiofibular arthrodesis was performed in skeletally immature patients when appropriate. At average follow-up of 60 months (range 33-83 months), all patients achieved bony union with full wrist range of motion compared with the contralateral extremity. The DRUJ was stable in all patients. Two skeletally immature patients with concomitant epiphyseal transfer showed continued skeletal growth. Two patients nearing skeletal maturity achieved revascularization of the distal ulna. Free vascularized fibular grafting is a successful option in the treatment of congenital ulnar pseudarthrosis. Reconstruction of the distal radioulnar and ulnocarpal joints using concomitant proximal fibular epiphyseal transfer should be considered in the skeletally immature patient with distal ulnar involvement.