Proximal scaphoid nonunion-osteosynthesis.

Abstract

Proximal pole fractures of the scaphoid have a high incidence of nonunion and avascular necrosis. Because of their poor prognosis, the treatment of these fractures remains controversial. 102 patients with symptomatic nonunion of the proximal pole were treated by simple osteosynthesis, using retrograde screw fixation through a direct dorsal approach to the scaphoid. Fracture preparation and bone grafting were kept to a minimum, in order to preserve as much bone stock as possible, and to avoid damage to the already compromised vascularity of the proximal fragment. No postoperative splinting was used and most patients were able to return to their normal work within a few weeks of surgery. 69 patients were followed-up at an average of 34 months. 59 (85%) were asymptomatic, and had regained excellent wrist function, in spite of the fact that sound radiological union was present in only 50% of these. Union was often slow (3 to 36 months) and appeared to be related to the vascularity of the bone fragments. However, even when bone union was incomplete, the fracture remained stable, with no loss of fixation. The ten patients with unsatisfactory results had all developed late avascular necrosis of the proximal pole, requiring salvage surgery. Stable internal fixation of proximal pole nonunion leads to rapid symptomatic improvement in the majority of cases and sets the scene for revascularisation and healing. Even when union is incomplete the scaphoid remains intact, thus preserving excellent wrist function and, at the same time, offering the best possible long term prognosis.