A 48-year-old woman presented to the emergency department complaining of wrist pain after a fall onto her outstretched hand. Examination revealed generalised carpal tenderness with a reduction in wrist movements. Following an x-ray she was diagnosed as having a carpal ligament sprain and discharged with a support bandage. The x-ray was later reported as a pisiform bone fracture (fig 1). She was recalled to the clinic and immobilised in a wrist splint. The fracture healed with no complications and she regained full functional use of her wrist.
Pisiform fractures are an uncommon injury accounting for only 0.2% of all carpal fractures.1 They are managed by immobilisation in either a plaster cast or a wrist splint. This fracture can be easily missed on first presentation due the superimposition of adjacent carpal bones.1 Fifty per cent are isolated fractures, and 50% occur in association with other carpal fractures.1 Magnetic resonance imaging is useful in confirming the diagnosis.2
Early diagnosis of pisiform fractures is important as missed diagnosis or delayed treatment may result in non-union. This presents as chronic wrist pain, grip weakness or restriction of wrist movements. Non-union is managed by surgical excision of the pisiform bone.3