Open triple fusion versus TNC arthrodesis in the treatment of Mueller-Weiss disease

BACKGROUND Mueller-Weiss disease is a rarely diagnosed deformity where the navicular bone undergoes spontaneous osteonecrosis in adults. Until now, there is no widely accepted operative treatment for this unusual disease. We aimed to compare clinical and radiological outcomes between the open triple fusion and talonavicular-cuneiform arthrodesis for Mueller-Weiss disease of stage 4. METHODS During the period from February 2012 to June 2016, 10 patients (11 feet) suffering from Mueller-Weiss disease of stage 4 were treated by the same senior surgeon. Among them, 5 patients (5 feet) were treated with open triple fusion and 5 patients (6 feet) were treated with talonavicular-cuneiform arthrodesis. Clinical outcomes were evaluated by American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score. Radiological results were assessed based on the X-ray and CT. Postoperative complications were also recorded. RESULTS There were no significant differences in AOFAS score between the two groups (p = 0.1 > 0.05). For the open triple fusion, the average AOFAS ankle-hindfoot score improved from 30.2 ± 3.27 preoperatively to 79 ± 3.81 at the last follow-up (p = 0.008). And for the talonavicular-cuneiform (TNC) arthrodesis, the average AOFAS ankle-hindfoot score improved from 33.2 ± 5.63 preoperatively to 86.2 ± 3.49 at the last follow-up (p = 0.007). CONCLUSIONS Both triple fusion and TNC arthrodesis are reasonable methods for the treatment of Mueller-Weiss disease if properly used. It is crucial to use radiological assessment to evaluate the involved joints preoperatively and then chose the appropriate method to treat different patients.