Scaphocapitate arthrodesis in late stages of Kienbock’s disease

Abstract

Background Kienbock’s disease is characterized by osteonecrosis of the carpal lunate. Kienbock’s disease treatment remains controversial. Objective To evaluate the short-term clinical and radiologic outcomes of scaphocapitate arthrodesis (SCA) in treating symptomatic late-stage Kienbock’s disease. Methods According to Lichtman’s classification, this prospective study included 21 patients with Kienbock’s disease stage III. All patients underwent SCA under general anesthesia. Patients were followed up at 1 and 2 weeks, 1, 3, 6, 9, 12, and 18 months postoperative. Results At the end of follow-up, 33.3% of patients achieved excellent outcomes, 47.6% achieved good outcomes, and 19.0% achieved poor outcomes. Patients with excellent and good outcomes are younger than patients with poor outcomes (38.9 ± 11.0, 42.2 ± 10.1, and 54.5 ± 3.3 years, respectively). Patients in the excellent and good groups had significantly lower disabilities of the arm, shoulder, and hand score (21.7 ± 14.8, 23.5 ± 16.8, and 47.3 ± 7.4, respectively, P=0.028), significantly higher extension/flexion arc (72.1 ± 17.2, 70.3 ± 22.0, and 38.5 ± 5.1, respectively, P=0.019) and a significantly shorter time to complete union (8.4 ± 1.4, 10.7 ± 1.3, and 14.8 ± 1.9, respectively, P=0.001). Conclusions SCA for late-stage Kienbock’s disease (stage III) was associated with significant improvements in carpal height length and grip strength postoperatively. Age, disease stage, disabilities of the arm, shoulder, and hand score, extension/flexion arc, and time to full union are critical factors in determining the prognosis of Kienböck’s disease.