Young people and the plantar release
by Dr. James C. Drennan

The older child and young adolescent who are experiencing unstable walking because of increasing foot deformity may be able to regain a better walk through a simple surgical procedure called a plantar release. It has been my experience that people aged eight to 14 who have CMT may benefit from this surgery which involves cutting the plantar fascia. Plantar refers to the bottom of the foot; fascia describes the inelastic fibrous tissue that coves the plantar muscles and extends from the heel to the toes. I'll show you in a diagram how the plantar fascia is cut to release the contracted plantar soft tissue. Some people experience a postoperative lengthening of one to two shoe sizes as the foot is permitted to become flatter and no longer has the exaggerated high arch.

This surgery is followed by a series of short-leg walking plaster casts, which may lead to further correction of the high arch. The person is allowed to put weight on the foot after the first cast change. Four weeks following surgery the patient is measured for a solid ankle-foot orthosis (AFO) which extends the entire length of the foot including the toes. The brace does no have a molded arch since the high medial arch was the deformity that required surgery correction.

The brace is initially worn both day and night to prevent recurrence and the person started on an active and active-resistive therapy exercise program for the peroneals (muscles that help you turn you foot outward - evert) and dorsiflexors (elevator) muscles. I would anticipate that the person will regain 30 to 40 degrees of active eversion within four to six months of therapy. Bracing requirements should decrease as the young person regains muscle function and strength. The original ankle-foot orthosis can be converted to a posterior leaf spring type and eventually a heel cup with a lateral wedge to assist in controlling movement of the heel turning inward can be utilized.

Charcot-Marie-Tooth is progressive and eventually the benefits from the surgery may be lost. However, the youngsters may have benefitted from improved walking during their most active years. It is worthwhile to obtain a single preoperative transverse CT scan of the midcalf (x-ray technique to assess the size and quality of the individual muscles) to determine the current condition of the peroneal and dorsiflexor muscles before considering this limited surgical and rehabilitation approach.