Background: As a minimally invasive therapy, botulinum toxin A (BTXA) treatment effectively reduces the hypertrophy of the gastrocnemius muscle (GM). Patient satisfaction is, however, reported to be low after treatment, with a possible correlation between high satisfaction and thinner subcutaneous fat. The goal of this study was to classify the subcutaneous fat of calves to understand the relation between fat thickness and patient satisfaction after BTXA treatment.
Methods: The maximal leg circumference was measured, and B-mode ultrasound was used to measure the thickness of the medial head of the GM and of the subcutaneous fat. Patients were followed up at 1 and 6 months after BTXA treatment.
Results: A total of 50 cases were classified into the following levels of fat thickness: slim (<0.55 cm), moderate (0.55 to 0.85 cm), and bulge (>0.85 cm). All patients were treated with 300 units of BTXA. Patients in the slim and bulge groups reported higher satisfaction rate than patients in the moderate group, with patients in the slim and bulge groups reporting complete satisfaction (100%) with calf contour at the 6-month follow-up. The satisfaction rate with the improvement in total leg circumference was low in all 3 groups. No severe complications were encountered in this study.
Conclusions: This study identified a U-shaped correlation between calf subcutaneous fat thickness and patient satisfaction rate after treatment. The authors' results provide a theoretical basis for BTXA treatment and suggest the importance of preprocedure conversations in GM hypertrophy treatment.
Clinical question/level of evidence: Risk, II.
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