Study design: A prospective clinical study of M-ULBD of lumbar spinal stenosis (LSS).
Objective: In this article, the authors describe the technique of M-ULBD for lumbar spinal stenosis, and reported 2-year follow-up results.
Summary of background data: Recent reports showed that atrophy of multifidus muscles and chronic low back pain after conventional laminectomy may relate to disturbance of the arterial supply caused by long duration of muscle retraction, extensive muscle stripping, and damage to the dorsal rami of the posterior branches.
Methods: A total of 56 patients with LSS were randomly divided into group A and B. The 27 patients in group A (15 males and 12 females) underwent M-ULBD. The other 29 patients in group B (18 males and 11 females) received conventional laminectomy. Japanese Orthopaedic Association score of low back pain, 10-cm visual analogue scale, creatine phosphokinase 3 days after operation, pre- and postoperative cross-sectional areas of multifidus were used to evaluate the clinical results.
Results: There was no significant difference in preoperative data between both groups. A total of 54 patients (27 in each group A and B) completed 2 years of follow-up. The postoperative Japanese Orthopaedic Association and visual analogue scale scores in both groups were improved significantly compared with the corresponding preoperative ones (P < 0.05). The postoperative creatine phosphokinase, visual analogue scale score of low back pain, and atrophy rate of multifidus CSA in group A are lower than those in group B (P < 0.05). Dural tear at the contralateral side occurred in 3 cases (11.1%) in group A and 1 case in group B (3.4%).
Conclusion: Our 2 years of follow-up shows that this method is efficient for lumbar spinal stenosis treatment; however, it still needs long-term follow-up and needs to be compared with other modified methods.
Level of evidence: 3.