Compensatory Hypertrophy of Calf Muscles After Selective Neurectomy

Background: Unexpected contour changes frequently occurred after surgical contouring of the calves by selective neurectomy of the nerve to the medial gastrocnemius muscle. We recently experienced a rather unusual case, in which the nerve to the medial gastrocnemius muscle was selectively transected on one side, whereas on the other side, the nerve to the soleus was transected by mistake.

Methods: To investigate the reason for the contour change, the authors compared the muscle volume ratio of the posterior compartment of eight normal calves of eight normal volunteers with two calves in the reported case by using MRIs.

Results: The volume ration of normal control calves was 0.22:0.12:0.66, respectively, for the medial and lateral gastrocnemius muscles and the soleus muscle. In the case of the calf with atrophy of the medial gastrocnemius muscle, the volume ratio was 0.13:0.20:0.67, respectively. In the case of the calf with atrophy of the soleus muscle, the volume ratio was 0.27:0.14:0.59, respectively.

Conclusions: Physician and the patient should keep in mind before the operation that even though one muscle in the calf is selectively atrophied after the selective neurectomy, the other muscles can hypertrophy for compensation, thus causing possible distortion of aesthetic result.