Risk factor analysis of the incidence of subsequent adjacent vertebral fracture following lumbar spinal fusion surgery with instrumentation.

November 16, 2019

OBJECTIVE:

This study aimed to evaluate the risk factors for adjacent vertebral compression fractures following lumbar spinal fusion with instrumentation.

METHODS:

A total of 669 patients who received lumbar instrumented spinal fusion between January 2012 and December 2015 were divided into two groups according to whether the adjacent vertebral body was fractured. The covariates recorded were age, gender, bone mineral density (BMD), and the number of fixed segments. The anatomic variables were pelvic incidence angle (PI), preoperative lumbar lordosis angle (Pre-LL), postoperative lumbar lordosis angle (Post-LL), Pre-Post LL（Loss of LL）, postoperative pelvic tilt (Post-PT), postoperative sacral slope (Post-SS), Pre-(PI-LL) mismatch, and post-(PI-LL) mismatch. A one-way ANOVA was performed with the abovementioned parameters and binary logistic regression analysis was used to determine the relative risk factors.

RESULTS:

The 669 patients were followed-up at a mean of 2.7 ± 1.1 years (range, 2-4 years). Twenty-seven patients demonstrated fractures in the adjacent vertebral body following surgery. Analysis by one-way ANOVA demonstrated that age, PI, Pre-LL, post-LL, Pre-Post LL, post-(PI-LL) mismatch, post-PT, and osteoporosis were potential risk factors (all parameters, p = 0.000). Furthermore, binary logistic regression analysis showed that a large Pre-Post LL (Loss of LL) , osteoporosis , and old age were also risk factors for adjacent vertebral compression fractures.

CONCLUSIONS:

A greater Pre-Post LL (Loss of LL), osteoporosis, and advanced age may be risk factors for fractures in the adjacent vertebral body of the fixed segment following lumbar fusion fixation.