Whole segmental pedicle screw fixation combined with posterior lumbar fusion for treating lumbar spinal stenosis associated with degenerative scoliosis in elderly patients

Objective: To investigate the effects of whole segment pedicle screw fixation and fusion on low back, lower limb function and the incidences of postoperative complications in elderly patients with lumbar spinal stenosis associated with degenerative scoliosis (SSS). Methods: One hundred and thirty elderly patients who were diagnosed with SSS and prepared for surgical treatment in our hospital from November 2013 to November 2014 were recruited. All these patients all had multiple segments affected and Cobb angles were all over 20 degrees. The patients either received whole segmental fixation combined with posterior lumbar fusion (WSF, n=70) or short-segment fixation combined with posterior lumbar fusion (SSF, n=60) in a random way. The treatment effects of surgery including changes of lumbar pain, lower extremity functions and Cobb angles and postoperative complications were evaluated and compared during the 2-year follow-up. Results: All the patients showed no abnormalities in the correction of the Cobb angles or the height of the intervertebral space during the follow-up. In WSF group, the number of fused segments was 11.2 +/- 2.8, while in SSF group, the number was 5.6 +/- 1.4, with an average fusion period of 3.5 months. The mean postoperative Cobb angles were 7.4 degrees and 12.2 degrees in the WSF and SSF group respectively with significant intergroup difference. The Japanese Orthopedic Association scores before operation and two years after operation were 11.32 +/- 2.32 and 12.89 +/- 2.11 respectively in WSF group and 11.43 +/- 1.94 and 11.98 +/- 2.19 respectively in SSF group with significant intergroup difference in the postoperative phase. The pain relief rates were 93% and 88% for WSF and SSF patients respectively which were similar between groups. There was no intergroup difference in the incidence of postoperative complications. Besides, the patients in WSF group demonstrated greater improvement in regards to ODI than those in SSF group (P<0.001). Conclusion: Whole segmental fixation can achieve better effects than short-segment fixation method when treating senile SSS.