Severe Equinus Deformity After Radiofrequency-Induced Calf Muscle Reduction

Abstract

Radiofrequency-induced calf muscle volume reduction is a commonly used method for cosmetic shaping of the lower leg contour. Functional disabilities associated with the use of the radiofrequency (RF) technique, with this procedure targeting the normal gastrocnemius muscle, still have not been reported. However, the authors have experienced several severe ankle equinus cases after RF-induced calf muscle volume reduction. This study retrospectively reviewed 19 calves of 12 patients who showed more than 20° of fixed equinus even though they underwent physical therapy for more than 6months. All were women with a mean age of 32years (range, 23-41years). Of the 12 patients, 7 were bilateral. All the patients received surgical Achilles lengthening for deformity correction. To evaluate the clinical outcome, serial ankle dorsiflexion was measured, and the American Orthopedic Foot and Ankle Society (AOFAS) score was evaluated at the latest follow-up visit. The presence of soleus muscle involvement and an ongoing lesion that might affect the postoperative results of preoperative magnetic resonance imaging (MRI) were investigated. Statistical analysis was conducted to analyze preoperative factors strongly associated with patient clinical outcomes. The mean follow-up period after surgery was 18.6months (range, 12-28months). At the latest follow-up visit, the mean ankle dorsiflexion was 9° (range, 0-20°), and the mean AOFAS score was 87.7 (range, 80-98). On preoperative MRI, 13 calves showed soleus muscle involvement. Seven calves had ongoing lesions. Five of the ongoing lesions were muscle edema, and the remaining two lesions were cystic mass lesions resulting from muscle necrosis. Ankle dorsiflexion and AOFAS scores at the latest follow-up evaluation were insufficient in the ongoing lesions group. Although RF-induced calf muscle reduction is believed to be a safer method than conventional procedures, careful handling is needed because of the side effects that may occur in some instances. The slow progression of fibrosis could be observed after RF-induced calf reduction. Therefore, long-term follow-up evaluation is needed after the procedure. Therapeutic case series.