Risk factor analysis of progressive spinal deformity after resection of intramedullary spinal cord tumors in patients who underwent laminoplasty: a report of 105 consecutive cases

Objective: Laminoplasty has been used in recent years as an alternative approach to laminectomy for preventing spinal deformity after resection of intramedullary spinal cord tumors (IMSCTs). However, controversies exist with regard to its real role in maintaining postoperative spinal alignment. The purpose of this study was to examine the incidence of progressive spinal deformity in patients who underwent laminoplasty for resection of IMSCT and identify risk factors for progressive spinal deformity.

Methods: Data from IMSCT patients who had undergone laminoplasty at Beijing Tsinghua Changgung Hospital between January 2014 and December 2016 were retrospectively reviewed. Univariate tests and multivariate logistic regression analysis were used to assess the statistical relationship between postoperative spinal deformity and radiographic, clinical, and surgical variables.

Results: One hundred five patients (mean age 37.0 ± 14.5 years) met the criteria for inclusion in the study. Gross-total resection (> 95%) was obtained in 79 cases (75.2%). Twenty-seven (25.7%) of the 105 patients were found to have spinal deformity preoperatively, and 10 (9.5%) new cases of postoperative progressive deformity were detected. The mean duration of follow-up was 27.6 months (SD 14.5 months, median 26.3 months, range 6.2-40.7 months). At last follow-up, the median functional scores of the patients who did develop progressive spinal deformity were worse than those of the patients who did not (modified McCormick Scale: 3 vs 2, and p = 0.04). In the univariate analysis, age (p = 0.01), preoperative spinal deformity (p < 0.01), extent of tumor involvement (p < 0.01), extent of abnormal tumor signal (p = 0.02), and extent of laminoplasty (p < 0.01) were identified as factors associated with postoperative progressive spinal deformity. However, in subsequent multivariate logistic regression analysis, only age ≤ 25 years and preoperative spinal deformity emerged as independent risk factors (p < 0.05), increasing the odds of postoperative progressive deformity by 4.1- and 12.4-fold, respectively (p < 0.05).

Conclusions: Progressive spinal deformity was identified in 25.7% patients who had undergone laminoplasty for IMSCT resection and was related to decreased functional status. Younger age (≤ 25 years) and preoperative spinal deformity increased the risk of postoperative progressive spinal deformity. The risk of postoperative deformity warrants serious reconsideration of providing concurrent fusion during IMSCT resection or close follow-up after laminoplasty.