Open coronal plane fracture of the distal phalanx treated by flexion block pinning: a case report

A distal phalanx may fracture in an atypical shape after high-energy trauma. A 61-year-old man sustained an open fracture of the distal phalanx of his left thumb while using a power saw. The fracture occurred in the coronal plane and the volar bone fragment was dislocated under traction by the flexor pollicis longus tendon. The patient underwent surgery the day after the injury. A flexion block pin was inserted to reduce the volar bone fragment, and an external flexion force was applied using a dorsal splint to compress the dorsal bone fragment into the volar bone fragment. The pin was removed 6 weeks postoperatively, and active range of motion exercises were started 8 weeks postoperatively. Bone union was achieved with good alignment, and although the interphalangeal joint remained slightly restricted in range of motion, the patient returned to his previous job and was satisfied with the function of the left thumb.