Treatment of Late-Onset Legg-Calve-Perthes Disease by Arthrodiastasis

BACKGROUND: To evaluate the efficacy of arthrodiastasis for Legg-Calve-Perthes disease. METHODS: Arthrodiastasis was conducted using external fixator devices (Orthofix) in 7 patients at least 8 years of age with a diagnosis of Legg-Calve-Perthes disease. The average follow-up was 80 months (range, 32 to 149 months), and their average age was 9.1 years (range, 8 to 12 years). The results of treatment were evaluated by measuring the degree of hip pain and the range of motion of the hip at 6 months after the operation and comparing the values with preoperative measurements. Radiological recovery was evaluated by the epiphyseal index and compared with the preoperative values. At the final follow-up, clinical and radiological results were evaluated using the Iowa hip score and the Stulberg classification. RESULTS: On the clinical evaluation performed at 6 months after arthrodiastasis, the degree of pain decreased by 1.8 points on average, and the average flexion, internal rotation, and abduction increased by 35°, 16°, and 11°, respectively. Based on radiological findings, the epiphyseal index showed a remarkable increase of 6.6 on average (from 19 preoperatively to 26 postoperatively). At the final follow-up, the average Iowa hip score improved from 65 points preoperatively to 84 points. There were 1 Stulberg class I hip, 2 Stulberg class II hips, 3 Stulberg class III hips, 1 Stulberg class IV hip, and no Stulberg class V hip. CONCLUSIONS: We conclude that arthrodiastasis using an external fixator can be a relatively promising surgical procedure for the treatment of late-onset Legg-Calve-Perthes disease.