What is the current thinking about the use of braces in the treatment of Legg-Calvé-Perthes disease? This was a popular treatment approach 35 years ago. But is it still relevant today? The authors of this article did an extensive search of the published literature on this topic and offer a summary of present opinion.
Legg-Calvé-Perthes (known as Perthes for short) is caused by a loss of blood supply to the epiphysis (growth center) of the hip. Without enough blood to nourish and replenish the bone, necrosis (cell death) occurs.
Deformity of the femoral head (round ball of bone at the top of the thigh bone) occurs. The affected bone starts to break apart (a process called defragmentation) and collapse. The end-result can be a change in the shape from a round femoral head to an oval or ovoid shape.
Instead of a ball in the socket with smooth, circular motion, the patient develops more of a mushroom-shaped hip. The femoral head is no longer encircled fully by the hip socket. Uneven wear on the oval-shaped head eventually leads to degenerative osteoarthritis. In some cases, severe arthritis develops early in adult life.
The goal of treatment is to prevent these complications. But the best way to do this remains unclear. Braces have been used to keep the hip fully in the socket and prevent changes in the shape of the femoral head. The idea in mind was to preserve the round head during the regeneration process. Bracing also limited how much weight the child could put on the hip. Less pressure through the hip was thought to help keep the round head of the femur in a spherical shape.
And, in fact, studies have supported the idea of keeping weight off the hip as necessary for a good result. At first, children were kept off their feet altogether. They did daily hip motion exercises and were able to keep the natural shape needed for hip mobility and flexibility. But staying in bed for a young, normally active child can be difficult and doesn't seem like a really good idea.
So the use of bracing was introduced. Well, actually the first orthopedic surgeons to study this approach (back in the 1970s) used plaster casts on both hips and legs. The child's legs were held far apart with a bar between the legs. Later a special "hip hinge" was developed to accomplish the same thing but allow better movement. They could walk with a walker and with limited weight through the hips.
The early results were positive and more studies were done trying all sorts of different casting and bracing ideas. Twenty years later (in the 1990s), several studies were done to review the results of this treatment approach. As it turns out, the results were actually pretty poor. Two-thirds of the children were not helped by the bracing. Analysis of the data showed that bracing should not be used with severe deformities.
New questions came up: are the results of using the casting method better, same, or worse compared with using braces? When should bracing be used? How long should braces be used? How can you know when it's time to start weaning the child off the supports? What factors make for the best results?
More studies were done. Over time, a clearer picture emerged. They found that treatment should be based on a classification system that divides patients by age and severity of disease. Mild disease (determined by X-rays) in younger children (five years old or younger) doesn't really need active treatment. Careful observation may be all that's required.
Right now, the prevailing thought is that treatment is advised when more than half the epiphysis is affected. Bracing may be recommended if the child is six years old or younger. Surgery may be a better option for children who are seven or older and who have severe disease. Most of the studies support the idea that treatment of any kind just doesn't seem to make a difference for mild-to-moderate disease in younger children.
In summary, the bracing idea has fallen out of favor in the treatment of Perthes hip disease. Bracing just doesn't seem to change the anatomy or alignment of the hip. There are some children who might benefit but they must be evaluated carefully and selected individually for this type of treatment.
Eligible children are younger and have significant (more than 50 per cent) of the epiphysis affected. They also have chronic inflammation of the synovial fluid in the joint and partial hip dislocation. X-rays show involvement of the lateral pillar (outside portion of the femoral head). Children who meet these criteria may be the best candidates for bracing. Results should be followed closely and discontinuation of bracing if no benefit is observed.
Reference: Christina K. Hardesty, MD, et al. The Role of Bracing in Legg-Calvé-Perthes Disease. In Journal of Pediatric Orthopaedics. September 2011. Supplement. Vol. 31. No. 2. Pp. S178-S181.