A one-hour, MDA-sponsored webinar features two physicians and the parent of a child with spinal muscular atrophy (SMA) who has undergone bracing and surgery for a spinal curvature, as well as questions and answers from listeners.
Below are highlights from the webinar.
Curvature of the spine is a common problem in children with neuromuscular disorders, particularly in children with SMA, said Tom Crawford, a child neurologist at Johns Hopkins University in Baltimore, where he co-directs the MDA clinic.
"The driving force for scoliosis [a side-to-side curvature of the spine] in neuromuscular disease is gravity," Crawford noted, adding that children with SMA who are able to sit independently at some point in their lives — generally children with type 2 SMA (SMA2) — have a greater than 90 percent chance of developing scoliosis.
Children who are able to walk independently at some point — generally children with type 3 SMA (SMA3) — develop scoliosis about 50 percent of the time, he said.
Children with SMA who are never able to sit or walk — generally children with SMA1 — often develop scoliosis as well, Crawford said.
Children with SMA often develop a "collapsing" type of scoliosis, which can develop suddenly, after some years of being relatively stable, Crawford said. This type of scoliosis is different from the type that affects children who don't have a neuromuscular disorder — so-called idiopathic (of unknown origin) scoliosis, which can develop very gradually and generally does not go into a sudden "collapse" mode.
Crawford advised parents of children with neuromuscular disorders to look at the child's back and see whether or not the spine is starting to curve to one side. If it is, the child should be seen by a specialist. (Check with your MDA clinic for a referral.)
Crawford is a proponent of bracing using a thoraco-lumbar-sacral orthosis, or TLSO, for children with neuromuscular spinal curvatures, as a way to put off doing surgery. Not every doctor agrees with bracing, he said, but in his experience, children with neuromuscular disease in general, and with SMA in particular, can benefit from a well-fitted TLSO. Although not a cure for scoliosis, a TLSO can allow spinal surgery to be postponed, particularly when the disorder is SMA, until a child is "at a later age when they're bigger and the results are better," Crawford said.
However, if the curvature is very severe or complex or if the child is very overweight, bracing may not be effective, and the child may need to go to surgery while still quite young.
Crawford noted that most children with Duchenne muscular dystrophy (DMD) do not develop scoliosis until after they have reached skeletal maturity and are nearly at their expected adult height, at which point there usually is no advantage to postponing spinal surgery. In fact, there's a disadvantage to doing so in DMD, as cardiac and pulmonary function often deteriorate after this point. These children generally do not need bracing but need surgery soon after a curvature develops.
Spinal fusion versus growing rods
Pediatric orthopedic surgeon Paul Sponseller works closely with Crawford and other neurologists and has performed spine-straightening surgery on many children with neuromuscular disorders.
Sponseller discussed two types of spine-straightening surgery:
Sponseller said that, in his experience, not everyone with a neuromuscular disease and a spinal curvature needs surgery, although many do. Patients with collapsing curvatures and those who have pain in the area of the curve need surgery, while those with a stable curvature who are not in pain may not need it.
Spinal fusion surgery, Sponseller said, is best performed after a child's major growth spurt, which generally occurs at around 12 years old in girls and 13 in boys. Fusions performed earlier stop the growth of much of the spine, although in some circumstances they may be the best option.
Sponseller said it's really never too late to do spinal surgery, but that, with time, the spine can become progressively more twisted, and respiratory function can deteriorate, both of which can make the surgery more risky.
Spinal fusion, he noted, prevents further curvature of the spine and displacement of the ribs; can maintain or improve respiratory function and sometimes intestinal function; allows a child to go without a brace; and allows easier sitting and a more upright posture.
A spinal fusion operation takes about four to six hours and is followed by an average of four to seven days in the hospital and one to three months at home or in a rehabilitation facility (out of school). It may take three to six months before a child "feels normal" after spinal fusion surgery, Sponseller said.
Surgery to insert growing rods, he said, is for children in whom full growth is far from complete, usually those who are younger than about age 9.
Growing rods are anchored at the top and bottom of the curvature but not in between, so that their length can be adjusted as the child grows. At this time, he said, such lengthening has to be done during a surgical procedure. However, in the future, it may be possible to do the rod lengthening without surgery, using an external device.
The rods allow a child to go without an external brace (they act as an internal brace) and can allow not only further growth but adjustment of the rods to allow for changes in the curvature.
A downside is that they require multiple surgeries.
Possible complications of spinal surgery, Sponseller said, include infection, bleeding, pneumonia, the need for assisted ventilation in the postoperative period and sometimes an unanticipated additional operation.
Going without spinal surgery if one needs it can lead to pain, breathing impairment and sitting difficulties.
Crawford said he tells families: "If you need spinal surgery, the only thing worse than having it is not having it."
After surgery, children may find that they have to eat and drink differently; that raising their arms or pushing down with their arms may be difficult; that they may be taller and stiffer; and that personal care, such as in the bathroom, may be more challenging.
Rachele Krebsbach and Payton Mueller describe their experience, offering encouragement and advice to families facing spinal surgery. Payton wore a brace for several years prior to insertion of growing rods, has undergone several rod-lengthening procedures, and has experienced some unexpected complications as well as overall success.