Neurofibromatosis contributing to carpometacarpal instability

Neurofibromatosis is well known to orthopedic surgeons for causing spinal curvature and tibial bowing. However, skeletal abnormalities of the hand related to this condition have rarely been reported. We present a unique case of neurofibromatosis causing bony changes possibly contributing to carpometacarpal instability. A 29-year-old man with neurofibromatosis type 1 presented with right hand pain after striking a wall. Swelling was difficult to assess as the hand was deformed due to a large plexiform neurofibroma over the ulnar side of the hand. Radiographs showed dorsal dislocation of the fourth and fifth carpometacarpal joints. Erosions, cystic changes, and rounding of the articulations were noted. Closed reduction and splinting were performed in the emergency room, but immediate redislocation occurred. Because of the inherent instability demonstrated clinically and radiographically, fixation was recommended; however, an open procedure was avoided to avoid dissecting through the neurofibroma. Percutaneous pin fixation was performed 1 week after injury, taking care to avoid the nerve lesion. Pins were removed at 6 weeks, and the patient was placed in a cast for an additional 4 weeks. At 6 months after injury, the patient was asymptomatic and had returned to prior level of function. Radiographs showed stable reduction.