82. OPENING-WEDGE VERSUS PROXIMAL CHEVRON OSTEOTOMY FOR HALLUX VALGUS WITH INCREASED INTERMETATARSAL ANGLE

Abstract

Purpose: For patients with moderate to severe hallux valgus with increased intermetatarsal angle, correction with a proximal first metatarsal osteotomy is indicated. The purpose of this study is to compare the opening-wedge osteotomy of the proximal first metatarsal the proximal chevron osteotomy in the treatment of moderate to severe hallux valgus with increased intermetatarsal angle.

Method: This prospective, randomized, multi-centered study is being conducted at three centers in Canada. Approximately 75 adult patients with hallux valgus are being randomized to either the proximal metatarsal opening-wedge osteotomy with plate fixation or the proximal chevron osteotomy. Patient functional scores using the SF-36, American Orthopaedic Foot and Ankle Society (AOFAS) forefoot metatarsophalangeal inter-phalangeal score and Visual Analogue Scale (VAS) for pain, activity & patient satisfaction, are assessed prior to surgery and 3, 6, 12 and 24 months. Surgeon preference is being evaluated based on a questionnaire and actual surgical times. Radiologic measurements (inter-metatarsal angle correction, hallux valgus angle correction, sagital talus-first metatarsal (Meary’s) angle, metatarsal length and union) will also be assessed.

Results: Preliminary results demonstrate that patients who undergo the opening-wedge osteotomy have less pain at 3 months (ave. VAS pain reduction 2.9, SE±1.0) than those with the chevron (ave. VAS pain reduction 2.4, SE±1.2). VAS for activity demonstrates greater improvements with the chevron osteotomy at 3 months (0.8, SE±0.8) versus the opening-wedge (0.1, SE±1.0). AOFAS scores improve on average 18.3 (SE±8.6) with the opening wedge compared to 20.8 (SE±7.4) with the chevron at 3 months. Average hallux valgus angle correction for opening-wedge and chevron osteotomies are 11.0 degrees (SE±2.5) and 19.0 degrees (SE±3.1) respectfully. Average intermetatarsal angle correction for opening-wedge and chevron osteotomies are 6.5 (SE±1.3) and 4.3 (SE±1.7) respectfully. Both procedures are effective at maintaining metatarsal length. The opening-wedge osteotomy takes on average 60.9 minutes (SE±3.9) to complete compared to 69.1 minutes (SE±5.1) for the chevron ostetotomy. Surgeon response to the new opening-wedge osteotomy is favorable.

Conclusion: Opening-wedge and proximal chevron osteotomies have comparable pain, function and radiographic outcomes. Opening wedge osteotomy is technically less demanding and requires less surgical time.