Why Surgeons Need to Intervene Sooner in Neuromuscular Scoliosis

Some children can’t even sit in their wheelchairs. Many are in significant pain. Declining lung function is common.

These are just some of the symptoms of curves that exceed 100 degrees in neuromuscular scoliosis. But they are largely avoidable, says Michael Heffernan, MD, a pediatric spine surgeon at Children’s Hospital Los Angeles.

“For kids with cerebral palsy and other neuromuscular conditions, there’s a tendency to not deal with scoliosis until it’s a major problem,” Dr. Heffernan explains. “Often, patients aren’t referred to us until a curve is over 100 degrees, or even 150 degrees. There is an epidemic of extremely large curves with these patients.”

Recently, Dr. Heffernan led a CHLA study that highlighted the critical need for earlier scoliosis referral and treatment of these children. Not surprisingly, the study showed that larger curves require more resources—and result in less correction—than smaller curves.

This fall, he presented the results at the Scoliosis Research Society meeting in Barcelona, Spain, and at the American Academy for Cerebral Palsy and Developmental Medicine conference in Quebec, Canada.

Continual progression

Children’s Hospital Los Angeles performs more than 300 spine surgeries a year and serves as a major referral center for all types of scoliosis—including more common forms like adolescent idiopathic scoliosis (AIS).

But the team is also one of the few in the country with deep expertise in neuromuscular scoliosis, which most commonly affects non-ambulatory patients with cerebral palsy.

“In AIS, scoliosis progression typically slows down once a child is done growing. But neuromuscular scoliosis worsens at a faster pace even after growth has finished,” Dr. Heffernan says. “There’s no benefit in waiting to intervene.”

That’s especially true because once curves reach 100 degrees, he recommends that patients receive preoperative halo traction to make the surgery more successful. That requires the patient to spend a month in the hospital prior to surgery—a significant burden on children and families.

There is an epidemic of extremely large curves with these patients.”

Michael Heffernan, MD

Key findings

In the retrospective study, the team looked at 337 patients between the ages of 7 and 21 with neuromuscular scoliosis who underwent spinal fusion surgery at CHLA. All patients had been followed for at least two years after surgery.

Researchers divided patients into two groups: those whose preoperative curves were less than 80 degrees, and those whose curves were 80 degrees or greater.

Rates of surgical complications between the two groups were similar. But the group with the larger curves had:

• 30% more blood loss
• Twice the rate of intraoperative traction use
• Average surgical times that were nearly 80 minutes longer
• Four times the rate of adjunctive surgical techniques (osteotomies, distraction rods, traction)
• Hospital and ICU stays that were each a day longer on average

After surgery, the group with the larger curves also had:

• Larger residual curves—an average of 45 degrees, versus 23 degrees for patients who started with smaller curves
• More pelvic obliquity—10.2 degrees versus 4.8 degrees

Next steps

The team next plans to examine how the extra time and adjunctive procedures involved with larger curves translate to higher health care costs.

Meanwhile, Dr. Heffernan recommends that physicians caring for children with cerebral palsy and other neuromuscular conditions refer them for scoliosis care much earlier. The textbook guideline for spinal fusion surgery is to intervene once a curve reaches 50 degrees—although that rarely happens in neuromuscular scoliosis.

“Curve magnitude is not the only factor to consider in surgical timing, but it is important,” Dr. Heffernan says. “If we can initiate these conversations once a curve progresses to 50 or 60 degrees, we can improve outcomes for these children.”