Ribs, screws and severe scoliosis: New and experimental approaches
By Peter Pollack
Four orthopaedic surgeons experienced in treating children with severe scoliosis discussed promising new treatments for the devastating disease at a media briefing on Friday morning. Moderated by B. Stephens Richards, MD, the panel included Behrooz A. Akbarnia, MD; Robert M. Campbell Jr, MD, and Richard E. McCarthy, MD.
“Traditionally, fusing the spine so that you end up with a short, straight spine has been considered an orthopaedic success,” said Dr. Campbell, “but scoliosis is not the only problem. The problem is what it does to the thorax, which is an engine of respiration.” He then related the story of a patient who had received surgery to correct scoliosis, yet later died of respiratory problems at age 25.
Expandable prosthetic ribs
To address this issue, Dr. Campbell helped develop the FDA-approved vertical expandable prosthetic titanium rib (VEPTR) device. The VEPTR was designed to combat a new disease, thoracic insufficiency syndrome, which is defined as the inability of the thorax to support normal respiration or lung growth. It is used to strengthen and stabilize the chest, opening up the rib cage and providing lungs with room to expand and grow.
The patient must return to surgery about every six months, so that the device can be adjusted to account for natural growth. The VEPTR is designed to telescope like a curtain rod, so the surgery is minor, requiring only a one-inch incision and approximately 30 minutes with the patient under general anesthesia.
Because the VEPTR can only telescope so far, the devices do need to be replaced from time to time as the patient ages, but Dr. Campbell states that the replacement surgery is relatively straightforward once the original VEPTR has been installed.
Dr. Campbell looks forward to a day when VEPTRs will be self-expanding, reducing or eliminating the need for semiannual expansion surgeries. He also predicts that new surgeries will be developed that make us of the prosthetic rib.
Rods and screws
Another option is the dual-rod technique. According to Dr. Akbarnia, this technique is more stable and has fewer complications than the traditional single-rod technique for spinal correction.
Dr. McCarthy presented a technique he developed, the Shilla procedure. The Shilla procedure is very new and experimental; whether it has a long-term future in the treatment of severe scoliosis is still undetermined.
Because traditional braces are only effective in curves of 40 degrees or less, the Shilla procedure is being used on patients who might not be able to survive otherwise. Dr. McCarthy begins with a blueprint of the spine, working out the forces and vectors involved in straightening it, and determining screw placement.
He then installs a pair of rods. The most curved portion in the center of the spine is held straight and fused. Ends of the rods are not fused, but held in place with growing screws, allowing the spine to lengthen without additional trips to the operating room. The screws capture the rods, but slide as the patient grows. He states that the Shilla procedure has allowed patients to avoid five additional surgeries compared to traditional techniques.
The procedure has only been performed and a small number of patients (average age of six years old) with an average curvature of 73 degrees. The average correction has been 23 degrees.
All of the physicians emphasized that much to be learned as these techniques are implemented. “In the past, many of the children that we work with weren’t expected to live at all,” explains Dr. Akbarnia. “This is a new area, and as they grow up, we will continue to learn from the issues they face.”