Fifteen per cent of acute fractures of the scaphoid waist fail to unite if treated non-operatively in plaster, resulting in persistent loss of function. Suspected risk factors for non-union include proximal fracture fragment avascularity and assessments of fracture displacement and comminution. This series of studies investigated whether one can accurately identify which scaphoid waist fractures will unite with plaster treatment. They suggest that proximal fracture fragment vascularity is not a predictor of outcome. In contrast, assessments of fracture displacement on magnetic resonance imaging (MRI) and computed tomography (CT) but not scaphoid series radiographs can be used to predict outcome. Undisplaced fractures are benign and unite reliably with 4-8 weeks' treatment in plaster. Displaced fractures with 3mm or more gapping have a significant nonunion rate if treated in plaster and might be better treated operatively. Use of MRI/CT may allow reliable, cost effective treatment of acute fractures through the scaphoid waist.The aim of treatment of scaphoid waist fractures is to achieve union. This is because one can then expect restoration of normal, painless wrist function within 6-12 months with no risk of late onset wrist osteoarthritis if the fracture unites. In contrast, there is often persistent pain and loss of wrist movement and function if the fracture fails to unite. Additionally, there is then a significant risk of symptomatic post-traumatic osteoarthritis in future years.It is often difficult to decide whether a scaphoid fracture has united 1 but research suggests that 85% or more of scaphoid waist fractures unite with treatment in a below elbow plaster cast for 8-12 weeks.2 This is still the standard management of these fractures in the UK. About 50% of units continue to use a scaphoid plaster, which immobilises the thumb but others, Nottingham included, use a Colles type plaster, which leaves the thumb free and allows better function.
3Although non-operative treatment of scaphoid fractures is the standard in the UK, it is becoming increasingly fashionable to treat these fractures operatively. It is argued that this benefits the patient because it avoids the need for lengthy immobilisation of the wrist in plaster. However, it has never been shown that operative treatment improves the union rate. Furthermore, there is no doubt that, in the hands of mere mortals, operative fixation has a significant complication rate that is mainly due to problems with screw placement. Finally, in the current financial climate, one has to ask if operative fixation of a fracture that usually unites with plaster treatment is cost effective. Although it is claimed that it is cost effective, operative fixation at best only reduces indirect costs, and only if non-operative treatment in plaster is continued for many weeks. Surgeons who favour operative fixation highlight the 15% non-union rate with treatment on plaster 2 as a reason for operative fixation. In contrast, those who favour plaster treatment argue that ...