Treatment of Scaphoid Nonunion by Vascularized Bone Flap Pedicled on 1, 2 ICSRA from the Dorsum of the Distal Radius

Introduction: To study the indication, techniques, and treatment outcomes of using a retrograde pedicled vascularized radius bone flap based on 1, 2 intercompartmental supraretinacular artery (1,2 ICSRA) to treat scaphoid nonunion.

Methodology and Material: Between February 2007 and October 2013, 23 patients with established scaphoid nonunion were treated with open reduction and internal fixation in addition to a retrograde pedicled vascularized radius bone flap based on 1, 2 ICSRA. Among these patients, 15 had nonunion of the scaphoid waist and 8 had nonunion of the proximal pole of the scaphoid. 12 patients were associated with avascular necrosis of the proximal fragments, 9 with humpback deformity of scaphoid and dorsal intercalated segment instability (DISI), and 4 with arthritis of radius styloid. A longitudinal incision was made on the radial dorsum of the wrist. Bone graft was fixed with crossed Kirschner wires in 19 cases, and with one Herbert screw and one Kirscher wire in 4 cases. 17 pedicled bone flaps were wedged in from the dorsum of the scaphoid, while 6 from its volar aspect. Postoperative evaluation included the time to union, the range of motion of the wrist, pain relief and grip strength.

Results: 20 patients were followed up and 3 were lost, the averaged follow up duration was 13 months, with the range of 6～21 months. Union rate was 22 of 23 (95.7%) and the averaged union time was 13.5 weeks. All patients achieved complete pain relief. The flexion and extension of the wrist were (57.3 ± 4.5) and (49.7 ± 5.9), respectively. The functional results were encouraging in all patients (14 excellent, 5 good, and 4 fair), which were measured using the modified Mayo Wrist Score.

Conclusions: Retrograde pedicled vascularized radius bone flap based on 1,2 ICSRA can promote scaphoid union, especially for those patients associated with proximal pole avascular necrosis.