This condition also goes by the name, “de novo” scoliosis. As the name implies, this variety begins in the adult patient due to degeneration of the discs, arthritis of the adjacent facet joints and collapse and wedging of the disc spaces.
A survey of neurosurgeon AANS membership assessed the deformity knowledge base and impact of current training, education, and practice experience to identify opportunities for improved education. Eleven questions developed and agreed upon by experienced spinal deformity surgeons tested ASD knowledge and were subgrouped into 5 categories:
1) radiology/spinopelvic alignment
2) health-related quality of life
3) surgical indications
4) operative technique
5) clinical evaluation.
Chi-square analysis was used to compare differences based on participant demographic characteristics (years of practice, spinal surgery fellowship training, percentage of practice comprising spinal surgery).
Responses were received from 1456 neurosurgeons. Of these respondents, 57% had practiced less than 10 years, 20% had completed a spine fellowship, and 32% devoted more than 75% of their practice to spine. The overall correct answer percentage was 42%. Radiology/spinal pelvic alignment questions had the lowest percentage of correct answers (38%), while clinical evaluation and surgical indications questions had the highest percentage (44%). More than 10 years in practice, completion of a spine fellowship, and more than 75% spine practice were associated with greater overall percentage correct (p < 0.001). More than 10 years in practice was significantly associated with increased percentage of correct answers in 4 of 5 categories. Spine fellowship and more than 75% spine practice were significantly associated with increased percentage correct in all categories. Interestingly, the highest error was seen in risk for postoperative coronal imbalance, with a very low rate of correct responses (15%) and not significantly improved with fellowship (18%, p = 0.08).
The results of this survey suggest that ASD knowledge could be improved in neurosurgery. Knowledge may be augmented with neurosurgical experience, spinal surgery fellowships, and spinal specialization.
A literature analysis highlighted several classification schemes developed for degenerative scoliosis patients: the Simmons classification system, the Aebi system, the Faldini working classification system, the Schwab system, and the Scoliosis Research Society system 4).
There are few radiographic markers to predict presence of radiculopathy. Emerging data suggest that spondylolisthesis, obliquity, foraminal stenosis and curve concavity may be associated with radiculopathy in ADS.
Full length standing radiographs in both the coronal and sagittal plane that include all segments of the spine as well as the pelvis and hips are essential in the diagnostic evaluation of adults with spinal deformity. From such radiographs the segmental alignment, regional curvatures and global balance can be measured. Pelvic parameters such as pelvic incidence and pelvic tilt will also help define compensatory mechanisms of deformity. Focal imaging studies may be necessary to assess for instability (flexion-extension radiographs). Advanced imaging studies (i.e. MRI or CT myelography) may be needed to assess patients with lower extremity symptoms or other neurologic signs or symptoms.
Coronal deformity is usually less symptomatic than a sagittal deformity because there is less expenditure of energy and hence less effort to maintain upright posture. However, nerve root compression at the fractional curve or at the concave side of the main curve can give rise to debilitating radiculopathy.
Findings demonstrate significant variability in health-related quality-of-life measures and radiographic parameters between North American and Japanese patients, supporting the need for population-adjusted sagittal modifiers to more accurately classify deformity 5).