Multi-segmental lumbar spinal stenosis treated with Dynesys stabilization versus lumbar fusion in elderly patients: a retrospective study with a minimum of 5 years’ follow-up

Middle- and long-term outcomes of multi-segmental lumbar spinal stenosis treated with Dynesys stabilization (DS) have rarely been reported. Older age and multi-segmental degeneration may be positive factors in achieving satisfactory outcomes following DS. The present study aimed to compare the middle- and long-term outcomes of DS with lumbar fusion for treatment of multi-segmental lumbar spinal stenosis (ms-LSS) in elderly patients. This study retrospectively analyzed patients with ms-LSS treated by DS or lumbar fusion from January 2011 to April 2013. Twenty-two patients were included in the Dynesys group, and 44 patients treated by lumbar fusion and rigid fixation were included in the fusion group. Clinical outcomes were assessed by VAS and ODI. Radiological outcomes were measured by range of motion (ROM) of stabilized segments and the proximal adjacent segment, intervertebral disc height (DH) and L1–S1 lumbar lordosis angle (LL). Modified Pfirrmann grade score was used to access disc degeneration. The mean follow-up time of the Dynesys group and fusion group was 68.50 ± 6.40 and 70.14 ± 7.26 months, respectively. Baseline data were similar between the two groups. There were no significant differences between the two groups in terms of improvement of clinical outcomes (VAS and ODI). DS preserved a certain degree of ROM (3.74 ± 2.00) of surgical segments. ROM of proximal adjacent segment underwent an increase in both groups at the final follow-up. The DH of the surgical segments and proximal adjacent segment in both groups was significantly lower than that before surgery (P = 0.000). LL of both groups improved (P = 0.000), and there was no significant difference between the two groups. The modified Pfirrmann score of proximal adjacent segment of both groups increased at the final follow-up. The fusion group underwent a more significant increase (P = 0.000), whereas the inter-group difference showed no significance (P = 0.090). DS is a safe and effective surgical treatment of multi-segmental lumbar spinal stenosis in the elderly population. DS preserves a certain degree of mobility of surgical segments.