The Treatment of Nonunion of the Scaphoid with a Horse-Shoe Bone Graft and Fixation with Two Screws

Abstract

Purpose: Three dimensional anatomical reconstruction of an old scaphoid nonunion injury with a humpback deformity is not an easy procedure. The single interpositional bone graft technique has its limitation for accurate anatomic reconstruction. We report here on the effect of a cortical interpositional horse-shoe graft using two screws and a volar cancellous chip bone graft for the treatment of scaphoid nonunion with a humpback deformity or a miss-match fracture surface in scaphoid nonunion. Materials and Methods: We retrospectively reviewed nineteen patients who were treated for scaphoid nonunion using a cancellous chip bone graft and a cortical interpositional horse-shoe graft with 2 screws (a Herbert's screw and a mini screw). The mean follow up period was 24 months (range: 14-36 months). The mean age was 30.5 years (range: 17-52 years) and 18 patients were male and 1 patient was female. The mean period between injury and operation was 6.7 years (range: 1 to 30 years). The nonunion sites were located in the waist in 15 wrists and in the distal third in 4 wrists. The volar approach was used in 18 cases and the dorsal approach was used in 1 case. In 2 cases, one additional kirschner's wire was used due to the instability of fixation. The clinical results were assessed by the criteria of Maudesley and Chen at the last follow-up. Results: Bony union was obtained in 18 (95%) cases. The average time for union was 13 weeks. There were improvements in the scapholunate angle (from 65.2 degrees to 49.5 degrees) and the intrascaphoid angle (from 43.5 degrees to 29.6 degrees). There are 3 cases with excellent results, 10 cases with good results and 6 cases with fair results. There was one complication. In 1 case, a nonunion gap was seen at 7 months after operation, but there were no clinical symptoms. Conclusion: A cortical interpositional horse-shoe graft using two screws and a cancellous chip bone graft for treating scaphoid nonunion with a humpback deformity or a large defect seems to be an encouraging procedure for regaining the normal anatomy of the scaphoid.