Lateral lumbar interbody fusion for severe lumbar spinal stenosis: a randomized controlled trial with 1-year follow-up / 中华骨科杂志

ABSTRACT

Objective:To investigate the clinical outcomes of minimally invasive lateral lumbar interbody fusion (LLIF) and the necessity to perform LLIF plus posterior direct decompression in the treatment of severe degenerative lumbar spinal stenosis (DLSS).Methods:In this prospective randomized, controlled trial, we assigned 71 patients, who were 50 to 80 years old, and diagnosed with severe DLSS (Schizas Classification grade C on magnetic resonance imaging), in a 1∶1 ratio to undergo either one-stage LLIF plus posterior internal fixation (treatment group) or CLIF plus posterior internal fixation with laminectomy (control group). Demographic and perioperative data were collected and compared. The clinical outcome measures included Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ) score as well as visual analogue scale (VAS). Patients were followed up for at least 1 year.Results:The treatment group included 36 patients with 46 surgical levels, while the control group included 35 patients with 46 surgical levels. The baseline demographic data of the 2 groups were equivalent in preoperative central canal areas, spinal canal anteroposterior diameter, disc height, ODI, ZCQ score for symptom severity and physical function, as well as VAS scores for back and leg pain. The mean operative time, blood loss, drainage volume and hospital stay of the treatment group are significantly less than the control group (157.2±29.1 min vs. 180.6±26.8 min, 75.6±39.1 ml vs. 108.6±43.3 ml, 136.9±73.9 ml vs. 220.5±121.3 ml, 5.3±1.1 d vs. 6.6±2.3 d). There were 2 cases with dura tear and 1 case with wound infection in control group. Thus, the surgical trauma and complications of the control group were more than the treatment group. At 1-year follow-up, the mean ODI score of treatment group improved from 42.24%±10.70% preoperatively to 18.21%±11.49%, the mean ZCQ symptom severity from 2.89±0.38 to 1.61±0.41, the mean ZCQ physical function from 2.31±0.45 to 1.50±0.37, the mean VAS for back from 5.56±1.19 to 1.97±1.13 and the mean VAS for leg from 4.44±1.81 to 0.94±1.26. At 1-year follow-up, the mean ODI score of the control group improved from 43.65%±14.93% preoperatively to 17.36%±12.15%, the mean ZCQ symptom severity from 2.92±0.52 to 1.65±0.39, the mean ZCQ physical function from 2.37±0.52 to 1.55±0.39, the mean VAS for back from 5.63±1.40 to 2.34±1.47, and the mean VAS for leg from 4.37±2.14 to 0.83±1.20. The ZCQ satisfactory score of both groups were not significant different (1.25±0.45 vs. 1.26±0.43, t=0.07, P=0.944). The mean improvement rate of both groups for ODI, ZCQ symptom severity, ZCQ physical function, VAS back and VAS leg at 1-year follow-up were not significant different (55.43%±27.74% vs. 58.36%±25.06%, 43.07%±17.22% vs. 42.66%±12.95%, 32.25%±23.65% vs. 31.71%±23.24%, 62.65%±21.25% vs. 58.37%±22.44%, 78.94%±26.41% vs. 85.45%±20.53%). One adjacent segment disease was found in each group at 1 year follow-up. Conclusion:CLIF+ posterior internal fixation in the treatment of Schizas Grade C DLSS has satisfactory clinical outcome at 1-year follow-up. Laminectomy increases surgical trauma, but does not significantly improve the clinical outcome at 1-year follow-up.