Introduction: Spinopelvic alignment significantly impacts health-related quality of life and postoperative outcomes. Despite the fact that spine tumors are known to cause significant vertebral body destruction and focal kyphotic deformity, the influence of global spinal alignment in the context of spine oncology remains unknown. As such, we conducted a retrospective cohort review of adult patients with spine tumors and investigated the incidence and association of spinopelvic deformity on outcomes after spine surgery.
Methods: A multi-institutional retrospective cohort study was conducted on 82 patients with spine tumors who received full-length spinal (scoliosis) x-rays at two, large tertiary medical centers over a period of 7 years. Patients were then compared between a PI-LL (pelvic incidence-lumbar lordosis) mismatch of ≤10 (appropriately aligned) or >10 degrees (positive sagittal imbalance) in terms of baseline characteristics, postoperative outcomes, and mortality. Continuous, nonparametric variables are expressed as median (interquartile range) and categorical data is expressed as frequency (%). Fisher’s exact test was used to compare categorical data and Wilcoxon rank-sum test was used for continuous data.
Results: Of these patients, 38 (46%) were found to have a PI-LL mismatch ≤10 degrees and 44 (54%) patients had a mismatch >10 degrees, denoting positive sagittal imbalance. Patients with sagittal imbalance were more frequently male (n=35 (80%); p=0.001), had extra-vertebral osseous metastasis (n=33 (75%), p = 0.04), and presented with pain (n=44(100%), p = 0.018). However, other characteristics including age, functional status, pathological vertebral body collapse, treatment approach and modalities, hospital length of stay and discharge location, postoperative complication rates, mortality and survival rates were relatively similar between groups over a follow-up duration of 20 (7-33.5) months.
Conclusion : This is the first study to demonstrate that the majority of patients with spine tumors may develop spinal deformity during the course of their disease process. While previous investigations have shown a negative correlation between positive sagittal imbalance and patient outcomes in the degenerative spine population, we did not find a significant difference in our spine oncology cohort. Ultimately, larger, prospective studies with standardized imaging and follow-up protocols are needed to further elucidate the impact of spinopelvic deformity on outcomes in patients with spine tumors.
