[The foot in hereditary motor and sensory neuropathies in children]

Although Charcot-Marie-Tooth disease (CMT) is known to be the most common neuromuscular cause of pes cavovarus, other paralytic deformities of the foot may be present with hereditary motor and sensory neuropathies (HMSN). The purpose of our review is to analyze these foot deformities and to assess the results of the different therapeutic methods used.

We evaluated 66 patients who had HMSN and had a total of 127 foot deformities. Fifty three patients had CMT, 6 patients Déjerine Sottas disease (DS), and 7 patients had an unclassified HMSN. The average age at diagnosis was of 9 years and 11 months. There were 35 males and 31 females. The deformity was unilateral in 5 cases. In 50 bilateral cases, the severity of the deformity was not similar in both feet. In three bilateral cases, the deformity was completely asymmetrical. The chief complaint was mainly deformity in all cases, followed by subtalar or ankle instability in 57 cases. There were 105 cases of cavus or cavovarus, and 22 cases or valgus or planovalgus deformity (8 of which changed spontaneously to cavovarus). A non surgical treatment was undertaken in 57 cases for minor deformity. Soft tissue release with or without osteotomies was done in 39 cases, and triple arthrodesis in the remaining 31 cases. A clawtoe deformity was treated operatively in 14 cases.

The mean follow-up period was 6 years and 9 months for non operated feet and 7 years and 10 months for operated feet (all of the surgically treated feet were reviewed after the end of growth). Three patients of the non operated group and 8 patients of the surgically treated feet underwent triple arthrodesis for a recurrence of the deformity. Thirty nine per cent of the feet which underwent triple arthrodesis (a total of 42 feet) were considered to have fair or bad result at 6 years and 3 months follow-up period.

The foot deformity in HMSN is of a wide variety. A valgus flat foot is not uncommon, especially in DS and unclassified neuropathies. The young age of the patient is not a contrindication to surgical management. Even if minor previous surgeries do not always succeed in avoiding recurrence of the deformity, they nevertheless prepare the foot fort a possible triple arthrodesis, that will be done in better anatomical conditions.