Osteonecrosis of the Lunate Following Low-Energy Trauma: A Case Report.

Abstract

Osteonecrosis of the lunate was first described by Austrian radiologist Robert Kienbock in 19101. Presenting symptoms include pain, loss of carpal mobility, and prominence in the dorsal wrist. Theories about the pathogenesis of Kienbock disease include repetitive trauma, attritional rupture of the surrounding ligaments, and vascular compromise of the lunate. This causes osteonecrosis and progressive collapse of the lunate. It usually presents as idiopathic osteonecrosis or, alternatively, after high-energy trauma that may cause dislocation of the lunate. In this case report we describe a case of osteonecrosis following a low-energy fracture of the distal part of the radius. The patient was informed that data concerning the case would be submitted for publication, and she provided consent. A fifty-four-year-old woman sustained a fracture of the distal part of the right radius after falling on some ice (Figs. 1-A and 1-B). She was treated with closed reduction and splinting at an outside institution. Six days after the incident, she presented to us with persistent wrist pain. Repeat imaging showed a displaced fracture of the distal part of the right radius with unacceptable dorsal angulation. The lunate appeared normal with no fracture, collapse, or signs of osteonecrosis. The patient was taken to the operating room two days later for closed reduction; the arm was placed in a long-arm cast under intravenous sedation. Because of other medical problems, including severe hypertension, congestive heart failure, hepatitis C, and depression, a prolonged procedure under general anesthesia was contraindicated. Initial anteroposterior (Fig. 1-A) and lateral (Fig. 1-B) radiographs showing the fracture of the distal part of the radius. Fig. 1-A Fig. 1-B At the first follow-up visit twelve days later, radiographs showed acceptable alignment of the fracture with maintenance of the reduction. The lunate had a normal appearance (Figs. 2-A and 2-B). One month after reduction, the patient was evaluated, and she reported no wrist pain. Radiographs revealed interval healing with some settling of the fracture. The radiographic …