Patterns of sitting spinal alignment in non-ambulatory scoliosis patients with paraplegia: an observational study.

Purpose: To classify sagittal spinopelvic alignment patterns of non-ambulatory scoliosis patients with paraplegia based on lateral sitting radiographs and explore their relation to clinical background and physical function.

Methods: We reviewed non-ambulatory scoliosis patients with paraplegia, excluding those with prior spinal surgery from a single-center database. Alignment patterns in sitting postures were classified into slump sitting (SS) and erect sitting (ES) based on the most posterior edge of the spine's location on lateral sitting radiographs. Radiographical spinopelvic sagittal alignment, demographics, and physical functions were analyzed. Clinical scoring for physical functions included Hoffer's ambulator classification, Hoffer's modified sitting classification, and the Modified Ashworth Score (MAS) for the severity of spasticity in the lower extremities. Percentages of patients without spasticity, with MAS of 0 indicating "no spasticity." were also compared between the two alignment patterns.

Results: Of 172 patients screened, 86 met inclusion criteria, revealing two distinct alignment patterns: SS showed greater thoracic kyphosis, smaller lumbar lordosis, pelvic retroversion, and hip hyperflexion compared to ES. No significant differences in demographic data or curve patterns were observed between groups. The SS group had a significantly higher percentage of patients without spasticity compared to the ES group (39.2% vs. 14.3%, P = 0.016).

Conclusion: Identified were two distinct sagittal alignment patterns in seated scoliosis patients with paraplegia, with potential influences from spasticity in the lower extremities. Recognizing these patterns can aid in assessing the function of sitting balance that includes the hip joint and in optimizing strategies for the treatment of scoliosis patients with paraplegia.