The scaphoid is the most common carpal bone to fracture. Nondisplaced scaphoid fractures can be missed when initial X-rays are read as normal and/or the injury is believed to be a wrist sprain. As many as 30% of scaphoid fractures may not be detectable on initial X-rays. Because the scaphoid has a poor blood supply to the waist and proximal pole, failure to treat fractures early can increase the likelihood of nonunion and osteonecrosis. This is why an MRI is often ordered when patients present acutely with anatomic snuffbox pain and negative X-rays, or an apparent occult scaphoid fracture. When patients present with a remote history of a fall and apparent scaphoid nonunion on X-ray, CT is the study of choice. CT offers the best study to visualize if bony healing across the fracture has occurred. Evidence or absence of healing is crucial in guiding further treatment.1,2
If patients are still symptomatic and there is no evidence of fracture healing at 3 months, then surgical treatment should be discussed. Left untreated, scaphoid nonunions can lead to osteonecrosis, carpal instability, carpal collapse, and late wrist arthritis. Scaphoid nonunions involving the proximal pole should be fixed surgically with a vascularized bone graft and screw fixation. Bone grafting has been shown to increase the rate of union over screw fixation alone. More invasive procedures such as proximal row carpectomy, intercarpal fusion, scaphoid excision, and wrist fusion are reserved as salvage procedures when a chronic scaphoid nonunion has advanced to wrist arthritis.2
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor-in-chief of the Journal of Orthopedics for Physician Assistants (JOPA).
References
- Merrel GA, Wolf SW, Slade JF. Treatment of scaphoid nonunions: quantitative meta-analysis of the literature. J Hand Surg Am. 2002;27:685-691.
- Raju PK, Kini SG. Fixation techniques for non-union of the scaphoid. J Orthop Surg (Hong Kong). 2011;19:80-84.
