Spinal Fusion Surgery for Spinal Muscular Atrophy

Progressive back muscle weakness often leads to scoliosis (curvature of the spine) in people with spinal muscular atrophy (SMA). Scoliosis is very common for people with type 1 or 2 SMA. It can cause breathing problems and reduced mobility.

The best way to treat scoliosis is surgery, usually with spinal fusion. The decision of whether to undergo this procedure depends on age and severity of scoliosis. However, spinal fusion is usually recommended because scoliosis usually gets worse over time.

The surgery is generally well-tolerated. People usually report improvements in balance, appearance, and quality of life after the procedure.

When do people with SMA need spinal fusion?

Scoliosis is common in children with type 1 or 2 SMA. Progressively weak back muscles cannot keep the spine straight. This can start as early as 8 to 9 months old but usually starts between 6 to 8 years old. Scoliosis usually worsens over time. Progression is slower in people with milder forms of SMA.^1-3

Scoliosis affects the appearance and can cause complications. This includes:^1,4

• Lower arm function and range of motion
• Loss of balance when sitting
• Breathing problems because of lower lung capacity

Spinal braces can provide comfort and improve quality of life. However, they usually cannot slow or prevent the progression of scoliosis. Braces can also cause breathing difficulties. We do not yet know how to best use braces to support the spine in SMA.^2,5

Because of this, spinal surgery is the most common way to slow or stop the progression of scoliosis. The most common surgical procedure is called spinal fusion. The decision to undergo a spinal fusion depends on:^1,2

• Age
• Severity of scoliosis
• Rate of scoliosis progression
• Breathing function
• Preferences of the child and family

Most cases of scoliosis get worse over time. This leads to breathing and functional limitations, so spinal fusion is often recommended. However, the need and timing of spinal fusion is specific to each person.

What can I expect during a spinal fusion?

During a spinal fusion, doctors will permanently connect 2 parts of the spine. This prevents them from moving or growing further. To do this, doctors place bone or bone-like material between the 2 parts. Rods, hooks, or plates may help hold the spine together while the fusion heals. Over a few months, the fusion becomes a solid unit.⁶

The operation is performed under general anesthesia. Doctors will make small cuts to access the spine from the front or back. They will prepare bone material to use to fuse the spine. This bone can come from someone else or your own body (usually the pelvis). Doctors then place the bone material between the 2 parts of the spine.⁶

A hospital stay of 2 to 3 days is often needed after the procedure. Pain and discomfort can be controlled well with medicines. Your doctor may also suggest wearing a brace while the spine heals and fuses. Physical therapists can help with movements that keep the spine properly aligned.⁶

What are the typical outcomes of spinal fusion?

Spinal fusion can improve comfort, appearance, and overall quality of life. People also tend to report improvements in sitting balance, stability, and arm function. In some cases, spinal fusion can achieve a 100 percent correction of the spine curvature.^1,3

Spinal fusion is usually a safe procedure. Possible complications during surgery include:^1,6

• Blood loss or blood clots
• Breathing issues
• Infection
• Pain or nerve damage
• Poor wound healing

What are other spine surgery options?

Spinal fusion is usually done for adults and children over the age of 10, after growing has stopped. Other procedures are available for younger children if scoliosis progresses early.^1,2

Another option for young children is the use of growing rods. These are expandable devices attached to the top and bottom of the spine. Every few months, the rods must be surgically lengthened. This method reduces spine curvature while allowing the spine to grow further.^1,7

To avoid repeated surgery, growing rods can be magnetically controlled. This is a new technology that allows for rod adjustment without surgery. This procedure is not yet common in the United States, but studies elsewhere have shown its safety and efficacy.^2,8

Another possible option for young children is “vertical expandable prosthetic titanium ribs” (VEPTR). These are similar to growing rods but are attached to the ribs or the spine. Small adjustments must be made every 6 months to allow for growth.¹

These options are less invasive and better for younger children. However, children may still require spinal fusion later in life. Talk to your doctor about all treatment options for scoliosis.