New adult scoliosis classification system may help doctors predict best treatment
Data can help show when to fuse beyond the affected level, circumferentially or to the sacrum.
BERGEN, Norway — A new adult scoliosis classification system appears effective for surgical decision making and devising nonoperative strategies.
“It is a classification based on equal level of deformity, the lumbar lordosis, the presence or absence of anterovertebral subluxation, and the global balancing of the spine,” said Sigurd H. Berven, MD. Frank Schwab, MD, and Jean-Pierre Farcy, MD, coauthors of this study, published the classification system 2 years ago.
Investigators examined treatments in adult patients with major thoracolumbar and lumbar curves defined by the new five-part classification system as type IV and V, respectively. “The classification system for adult deformity has some good utility in predicting and guiding strategies for care,” Berven said at the International Society for the Study of the Lumbar Spine 33rd Annual Meeting.
In time, the system might contribute to more evidence-based approaches for adult scoliosis, he said. “Right now there certainly is tremendous variability in terms of surgical approaches of managing lumbar deformity” in adults, said Berven, who is at the University of California-San Francisco. Uncertainty also exists over indications for operative vs. nonoperative care, osteotomy, limited decompression, limited vs. extensive arthrodesis, and which levels to fuse and whether to fuse posteriorly or circumferentially.
Researchers recorded information about the scoliosis curves of 806 adults and their treatments. Investigators applied the classification’s parameters to each patient’s curve and rated it according to the system’s key modifiers: lumbar lordosis (A=normal, B=hypolordotic, C= practically kyphotic) and subluxation (0=none, +=some subluxation, ++=significant subluxation).
Three hundred-eleven patients had thoracolumbar curves and 495 patients had lumbar curves (average age 53 years, most were women); 348 patients were treated surgically (43%).
At risk for surgery
Looking at the rates of operative treatment, Berven noted that, “Patients who were more hypolordotic or practically kyphotic across the lumbar spine were more likely to have surgery.” For example, 51% of those with type B lordosis had surgery vs. those with type A lordosis (P<.05).
Other key findings:
- Patients with significant vertebral subluxation and those with very positive sagittal balance showed a strong trend toward surgery.
- At the least, fusions went across the main level involved in the curve’s apex.
- Most surgeons extended fusions at least one level beyond the subluxation.
- Patients with lumbar curves were more likely to get fused to the sacrum.
- Fusions ended at L4 or L5 in those with good sagittal profiles.
- Anterior surgery was the treatment choice for good lumbar lordosis and sagittal balance, minimal subluxation.
- Lumbar kyphosis typically led to posterior surgery with osteotomy.
For more information:
- Schwab F, Farcy J-P, Bridwell K, et al. Surgical treatment analysis of 809 thoracolumbar and lumbar major adult deformity cases by a new adult scoliosis classification system. #45. Presented at the International Society for the Study of the Lumbar Spine 33rd Annual Meeting. June 14-17, 2006. Bergen, Norway.