Spinal muscle atrophy (SMA) is a heritable disease characterized by the loss of a special type of nerve cells called motor neurons. These nerve cells are mostly located in the spinal cord, and control the movement of voluntary muscles. Their loss leads to progressive muscle weakness and atrophy, particularly around the spine but also elsewhere in the body.
What is scoliosis?
Muscular atrophy around the spine can lead scoliosis, a condition in which the spine bends and most often into an “S”-shape. Most SMA patients develop scoliosis, many while they are still children. Scoliosis often becomes progressively worse as a person ages.
Scoliosis can lead to other complications, such as problems with breathing because the curved spine deprives the lungs of room in which to expand. It also can reduce mobility, leading to joint stiffening. Some people with scoliosis may lose the ability to move their arms and hands.
Scoliosis in SMA patients often affects the hip joints, twisting the joints because the spine cannot straighten, especially in patients who cannot walk. It is estimated that 10 to 30 percent of type 2 and 3 SMA patients experience partial or complete hip dislocation.
Scoliosis can be treated with surgery or braces.
Braces are typically hard plastic devices worn like a jacket to support the torso, often from underneath the arms to the waist. Some physicians think that braces can delay the progression of scoliosis and improve patients’ quality of life, although there is some debate in the medical community about this.
There are many styles of braces, and physicians usually work with patients to choose the brace style that works best for them, taking into account such factors as the patient’s degree of scoliosis and age.
Different types of surgery can be performed to treat scoliosis, and surgery is often recommended because of this condition’s progressive nature. Patients should work with their healthcare team to find the best treatment option for them. Most spinal surgeries are rarely recommended for children age 10 or younger because they are still growing.
- Hip relocation surgery can be performed to replace the ball of the thigh bone into the hip socket.
- Spinal fusion is a surgery in which two or more vertebrae are permanently connected or “fused.” Bone grafts or bone-like materials are placed between the vertebrae and fixed with rods and screws while the fusion heals. This type of surgery is for patients who can no longer walk and are over age 10, as fusion prevents further growth of the spine.
- Growing rods are expandable devices that are attached to the top and bottom of the spine with screws or hooks to force the spine to remain straight. Growing rods allow for future growth of the spine and are used in young children with severe scoliosis (greater than 40-degree curve), but need to be adjusted every few months.
- Magnetically controlled growing rods are very similar to growing rods for young children with severe scoliosis. They are a new type of growing rod approved in Europe and Asia, but not the U.S. The movement of these rods can be controlled by a magnet outside the patient’s body, so there is no need for additional surgeries to adjust their length. Potentially, the rods could also be used as a brace in patients with milder scoliosis.
- Vertical expandable prosthetic titanium ribs (VEPTR) are very similar to growing rods. Here, the rods are attached to the ribs or the spine. The device straightens the spine and separates the ribs, improving breathing and lung capacity. Surgery is required to make small adjustments every six months to allow for growth.
Pros and cons of scoliosis surgery
Scoliosis surgery can preserve lung function and reduce the need for nursing care. It can also improve patient comfort, appearance, and quality of life. Patients undergoing this surgery generally have better sitting balance, more stable spine and trunk, and better arm movement. Scoliosis surgery can also help to relieve back pain and prevent the development of hip displacement.
Some types of spine surgery can also prevent doctors from performing a lumbar puncture to deliver medication such as Spinraza (nusinersen) intrathecally or between the vertebrae. Patients should discuss this possibility with their doctor if it is a concern.
SMA News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.