Chronic lunotriquetral instability: diagnosis and treatment.

Fourteen patients with chronic lunotriquetral instability were evaluated. Forced wrist extension was the most common mechanism of injury. Fourteen patients underwent lunotriquetral arthrodesis. Arthrograms were positive in 9 of the 12 performed. In three cases abnormalities not identified by arthrography were demonstrated by arthroscopy. The follow-up period averaged 27 months. X-ray films showed fusion in 12 cases. One pseudarthrosis was asymptomatic. A second pseudarthrosis required a rearthrodesis that became solid 8 weeks after surgery. One patient had persistent wrist pain. Wrist motion compared to the contralateral side averaged 85%, 88%, 83% and 80%, respectively, for flexion, extension, ulnar deviation, and radial deviation. Grip strength compared to the contralateral side averaged 93%. Lunotriquetral instability is a clinical diagnosis confirmed by arthrography or arthroscopy. Lunotriquetral fusion reliably relieves pain while maintaining functional wrist motion and grip strength. The long-term effects of lunotriquetral fusion on carpal kinematics and wrist function are unknown.