A prospective study of midfoot osteotomy combined with adjacent joint sparing internal fixation in treatment of rigid pes cavus deformity.

BACKGROUND: Midfoot osteotomy has been previously confirmed to be a good method to correct pes cavus. How to fix the osteotomy and which point to choose for the procedure has been a focus for most surgeons. The aim of this study was to analyse the outcomes of a series of patients who had been treated for pes cavus deformity using midfoot osteotomy combined with adjacent joint sparing internal fixation.

MATERIALS AND METHODS: Between 2008 and 2012, 17 patients with a mean age of 16.8 years (12-36 years) were tracked after treatment by midfoot osteotomy combined with adjacent joint sparing internal fixation with three cannulated screws between the Lisfranc line and Cyma line. Clinical outcomes were assessed by measuring improvements of appearance and function, American Orthopedic Foot and Ankle Society (AOFAS) scores, and radiographic changes.

RESULTS: The mean follow-up time was 25.3 months (range, 10-50). The mean healing time from the osteotomy was 7.8 weeks (range, 6-12). The appearance and weight-bearing function were significantly improved in all patients. At a final follow-up, the mean AOFAS score was 75.8/100 points (range, 63-90). The mean Meary's angle, calcaneal pitch angle, tibiotalar angle, and Hibb's angle values improved from 26.3 to 5.5, 44.5 to 28.3, 133.1 to 100.8 and 66.9 to 41.1, respectively. Adjacent joints presented no obviously arthritic degeneration at the follow-up. Subjectively, 94.1% of patients were very satisfied or satisfied with minor reservations. Objective outcomes were excellent or good in 88.2% of feet.

CONCLUSION: For the treatment of rigid pes cavus deformity, extra-articular midfoot osteotomy combined with adjacent joint sparing internal fixation is effective and safe. This surgical technique is especially effective with low rates of arthritic degeneration and joint stiffness in the adjacent joints and little reduction of ankle and foot flexibility.