Displaced distal radius fracture presenting with neuropraxia of the dorsal cutaneous branch of the ulnar nerve (DCBUN)

Nerve injuries, mostly to the median nerve, are common following distal radius fractures. Ulnar nerve injuries are rarely encountered, with only few case reports of motor or motor and sensory loss described in the literature. In this paper, we report two consecutive cases of young patients with a distal radius fracture and a pure sensory ulnar neuropathy. Both patients had a radially displaced fracture and presented with sensory loss and paresthesia in the distribution of the dorsal cutaneous branch of the ulnar nerve (DCBUN), which resolved after fracture reduction. We believe this clinical scenario is the result of traction or compressive neuropraxia of the DCBUN in the subcutaneous tissue around the ulnar styloid—a neurologic injury which had not yet been described for distal radius fractures.