A lateral (side-to-side) curvature of the spine is known as scoliosis. This kind of problem is common in muscular dystrophy (and in many other conditions), and its origins are somewhat similar to the origins of joint contractures. Kyphosis, a hunchback type of curvature, is also often present in DMD. Spinal abnormality, lordosis, is a swayback curvature. It's usually seen while the boy with Duchenne is still walking.
The muscles of the back weaken, but not always symmetrically. The muscles on one side may be a little weaker than those on the other, pulling the flexible spine out of alignment. The spine is made up of a string of bony disks known as vertebrae, and these can bend or be rotated, within limits, in all directions.
The best time for scoliosis surgery in DMD is between ages 11 and 13, before vital capacity (the volume of air that can be exhaled after a deep breath) falls too far. During scoliosis surgery metal rods are inserted along the spine to hold it in place while the vertebrae fuse.
Severe scoliosis can interfere with sitting, sleeping and even breathing, so it should be prevented. If the curve is progressing rapidly, surgery is often advised, usually between ages 11 and 13.
In rare situations, straightening the spine worsens breathing or swallowing, while at the same time alleviating other problems. A careful evaluation of which muscles a young man is using for these functions should be done before surgery is undertaken.
