Surgery and CMT
Most patients who have moderate to severe CMT disease can be helped with surgery. If performed early enough, surgeries like tendon transfers and osteotomies can increase strength and endurance by removing deforming forces in the joint; however, if the condition progresses to a fixed deformity, more invasive measures such as triple arthrodesis is needed. To highlight the complexities that surround the decision to have surgery across the lifespan, surgeries for adults and children are explored.
The mainstay of orthopedic treatment for children with CMT is physical therapy to strengthen muscles, stretching to avoid contractures, and bracing to stabilize gait. In addition, the pediatric orthopedic surgeon will monitor your child for potential associated problems including physical examinations and radiographs looking for scoliosis and hip dysplasia.
Some children will ultimately require one or more surgeries to correct deformities that can occur in spite of good therapy. These can be broken down by area, including the foot, the spine (for scoliosis), and the hip (for hip dysplasia).
The majority of surgeries performed on children with CMT involve the foot. Patients with CMT develop weakness in the peroneal muscles and tibialis anterior, as well as the intrinsic muscles of the foot. These first two muscle groups assist in dorsiflexion of the ankle and eversion of the foot. As they become weak, contractures can develop, resulting in equinus (the foot stuck pointed down), cavus (a high arch), and varus of the heal. Claw toes results from intrinsic weakness as well as an attempt to use the long toe extensors to dorsiflex the ankle. Cavus and varus deformities often go hand in hand and are not able to be braced.
This results in the child walking on their tiptoes. It is important to recognize that walking a little on the tip-toes is not necessarily a bad thing. But if the contracture becomes severe, the child may have trouble balancing. When this occurs, the surgeon may recommend a heel-cord lengthening to allow the foot to come up to neutral. It is important that the heel-cord not be over lengthened, as a calcaneus deformity (walking on the heels) may occur, and this is much worse than an equinus deformity.
The high arch is a result of weakness in dorsiflexion as well as clawing of the toes as the toe extensors try to take the place of the weakened tibialis anterior. Treatment for these deformities range from tendon transfers to releasing the plantar fascia (tight band on the sole of the foot), to osteotomies (realigning) of the bones of the foot. Frequently, these types of surgeries will be combined.
Varus of the hindfoot:
This usually accompanies the cavus deformity. As the claw toes worsens, the heel tilts inward, resulting in the child walking on the outside border of the foot. This often results in the patient developing painful callosities and experiencing frequent ankle sprains. Treatment for varus includes calcaneal osteotomies to move the heel laterally and sometimes tendon transfers.
The goal of these surgeries in children is to keep them walking comfortably, with feet that are well aligned and able to be fit with a brace if necessary. In addition, early surgery is often recommended in order to prevent progression to very rigid fixed deformities that can only be treated with joint fusions such as a triple arthrodesis. While joint fusions can make the position of the foot better, they result in a stiff foot and are best to avoid if possible.
Scoliosis (a fixed lateral curvature of the spine) occurs in about 38% of children with CMT. Unlike the more common adolescent idiopathic scoliosis which produces decreased kyphosis (decreased roundback) of the thoracic spine, scoliosis associated with CMT often results in an increase in kyphosis (increased roundback). Scoliosis associated with CMT does not seem to respond well to bracing, and if progressive, spinal fusion is sometimes needed. Your pediatric orthopedic surgeon will monitor your child’s spine regularly and order radiographs when necessary to evaluate the curvature. Unfortunately, there is no evidence that special exercises, chiropractic manipulation, or other non-surgical treatments have any effect on the natural history of the curve.
Hip dysplasia can occur in up to 8% of patients with CMT and is often silent. The child has no pain or limitation in motion. It can develop over time and result in early arthritic change in the joint. The cause of the arthritis is generally believed to be increased stress on the cartilage from lack of coverage of the femoral head. Your pediatric orthopedic surgeon will monitor your children with regular radiographs of the pelvis during their growing years to determine if hip dysplasia is developing. If it does, surgery may be recommended to improve the coverage of the hip joint. These types of surgeries can occur around the acetabulum (cup), on the femoral side, or both.
What a parent should do?
As the parent of a child with CMT, you should keep informed about the disease and your child’s condition. Be sure your child is followed by a knowledgeable pediatric orthopedic surgeon.
Ask questions! Write them down before the appointment so you do not forget anything. Be wary of internet sites that claim they can cure your child’s condition or deformity by manipulation, diet, or “special” therapies. If you do come across treatments that you want to consider, bring this information to your surgeon for his/her review.
Understanding your child’s condition and the options available for treatment is the best way you can help your child live a happy, healthy life. Visit HNF’s Healthcare Provider Directory to find a surgeon in your area.