Chronic capitolunate instability.

Twelve patients, twelve to thirty-two years old, were evaluated for complaints of chronic vague pain, weakness, and clicking in the wrist that had followed a significant but remote dorsiflexion injury to the wrist. Although a standard orthopaedic examination and plain roentgenograms of the carpus were unremarkable, a dorsal-displacement stress test done under fluoroscopic control with the radius fixed showed dorsal subluxation of the capitate out of the cup of the lunate, accompanied by a marked feeling of apprehension by the patient. This was also associated with a painful snap or click due to a sudden dorsal attitude and ulnar shift of the lunate, best elicited with the wrist in slight ulnar deviation. We believe that this condition is due to attenuation of the radiocapitate ligament resulting from prior trauma. Eleven patients were operated on. The volar radiocapitate ligament was tightened by tethering its central portion to the radiotriquetral ligament, partially obliterating the space of Poirier. Slight extension of the wrist was lost by this procedure, but the capitate could no longer be passively displaced and the lunate became stable. Using both objective and subjective criteria, six patients had an excellent result; three, good; one, fair; and one, poor. There was an average final loss of 15 degrees of extension and 19 degrees of flexion of the wrist. The average length of follow-up was four years and four months (range, twenty-four to 109 months). We concluded that insufficiency of the radiocapitate ligament after trauma to the wrist is one cause of chronic symptomatic capitolunate instability. Shortening of the radiocapitate ligament is recommended to stabilize the lunate and capitate.