Functional outcome with scaphotrapeziotrapezoid arthrodesis in the treatment of Kienböck's disease stage III.

Scaphotrapeziotrapezoid (STT) arthrodesis for the treatment of Kienböck's disease is recommended as a wrist salvage procedure since the publication by Watson and colleagues in 1985. Stage IIIa/b of the Lichtman classification is the specific indication for this operative-procedure. This study reviews the results of 26 patients with stage III of Kienböck's disease treated with STT arthrodesis during a 6-year period. From 1993 to 1998, 26 patients (16 men, 10 women) were treated with STT arthrodesis for Kienböck's disease in stage IIIa/b. The mean follow-up was 35 months. Two-rung grip strength was measured by using an electronic computerized JAMAR-Dynamometer. Pain was evaluated pre- and postoperatively using a visual analog scale. Patients' activities of daily living and general quality of life were estimated with the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. Also two established wrist scores (Mayo wrist score and Krimmer wrist score) including objective and subjective parameters were used. Fusion was established in 25 patients after an average period of 7 weeks. Pain was reduced substantially to 72% of the preoperative values under resting conditions and 60% under stress. Eight patients claimed complete pain relief. Grip strength improved to 60% of the opposite side. Active range of motion was 65% of extension/flexion and 50% of radial/ulnar deviation on average compared with the contralateral hand. Twenty of the 26 patients were satisfied with the final result and would undergo the operation again. A total of 80% of the patients returned to their original occupation. The average DASH score was 24.8, the Mayo and Krimmer wrist scores averaged 66 and 67.8 points respectively. The procedure combines the advantages of decreasing load to the lunate and maintaining carpal height. Pain was markedly reduced, grip strength improved, and functional wrist mobility was preserved. The data support increasing confidence that STT fusion will stand the test of time.