Classification of gastrocnemius muscle hypertrophy for personalized botulinum toxin type A treatment

Abstract Background Owing to its safety and convenience, botulinum toxin type A (BoNtA) has become a first‐choice treatment for contouring calf muscle asymmetries or deformities. Different injection methods and dosages have been discussed in the literature, but a standardized BoNtA treatment remains unclear. Aims This study aimed to classify gastrocnemius muscle hypertrophy (GMH) through multiple measurements to provide a personalized BoNtA treatment protocol. Methods The measurements combining of gastrocnemius muscle (GM) contour, max leg circumference and GM thickness was applied to classify different type of GMH in a normal population. Based on these findings, a personalized BoNtA treatment protocol was determined and evaluated regarding max leg circumference, GM thickness, the position of max leg circumference, patient and doctor satisfaction rate, and complications. Results A total of 100 GMH were classified into two bulging types (bilateral‐bulging type and unilateral‐bulging type) and two categories (moderate GMH and severe GMH). 40 cases were treated with personalized BoNtA injection methods (“Even” or “Intense”method) and dosages (300 or 400 units). Follow‐up examinations at 1, 3, and 6 months after treatment. Max leg circumference and GM thickness decreased significantly and the position of max leg circumference rose prominently during treatment (2.56 1.93; p 0.05). The overall patient satisfaction rate was 70%–100%. No serious complications occurred. Conclusions We identify four groups of GMH through several measurements and outline a personalized BoNtA treatment for each type. This recommended protocol may improve the therapeutic outcomes and patient satisfaction after treatment.