Spinal Claudication in Degenerative Lumbar Spondylolisthesis: Is Fusion a Must?
Authors: Wen Eleanor , Wong Chung Ting Martin , Cheng Hung On , Cheung Ka-Kin 
Published: May 2015

Introduction

North American Spine Society published an evidence-based clinical guideline in 2008 to address clinical questions concerning the diagnosis and treatment of degenerative lumbar spondylolisthesis (DLS). The society recommended surgery for symptomatic patients who have failed conservative management; supplementation with fusion to improve clinical outcomes. The majority of clinical studies included multilevel spinal stenosis or decompression achieved with laminectomy, and thus renders comparison between decompression with and without fusion difficulty. This is a retrospective cohort to examine the clinical outcomes of fenestration of lamina and laminectomy with instrumented fusion in the treatment of symptomatic spinal stenosis due to DLS at L4/5 level.

Patients and Methods

A series of 53 patients with single-level DLS and associated spinal stenosis at L4/5 were treated at a single institution from 1 January, 2007 to 31 December, 2012. The mean follow-up period was 35.5 months. Fenestration alone was offered to patients who did not have mechanical back pain. Patients who suffered from spinal claudication and mechanical back pain were offered decompressive laminectomy with concomitant instrumented fusion. Operative details including operation time, blood loss, and length of hospital stay were reviewed. Clinical outcomes were assessed with visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) lumbar score, and Oswestry disability index (ODI) preoperatively, at 6 months, 1 year, and the latest follow-up. Radiographic parameters and patients' satisfaction were also documented.

Results

A total of 26 patients underwent fenestration alone and 27 patients underwent laminectomy with concomitant instrumented fusion. The mean age at operation was 60.8 years. There were no differences in the demographic features between the two groups. No differences were detected in preoperative VAS (nonfusion: 6.6; fusion: 6.9), JOA lumbar score (nonfusion: 16.2; fusion: 14.4), ODI (nonfusion: 49.7; fusion: 48.5), and radiographic parameters between the two groups. Significant improvements were achieved in postoperative clinical outcomes and patients' satisfaction in all time periods for both groups. There were no significant differences demonstrated in postoperative clinical outcomes between the two groups (VAS nonfusion: 2.7, fusion: 3.2; JOA nonfusion: 24.1, fusion: 22.4; ODI nonfusion: 31.7, fusion: 30.6; patients' satisfaction nonfusion: 75.0%; fusion: 66.9%). There were no significant slip progression and change in translational motion on postoperative radiographs in the fenestration group. Fenestration alone required shorter operation time (nonfusion: 126.0 minutes; fusion: 274.4 minutes), less blood loss (nonfusion: 102.9 mL; fusion: 548.2 mL), and shorter hospital stay (nonfusion: 4.4 days; fusion: 8.6 days). No patient of nonfusion group had intraoperative dural tear while two patients of fusion group suffered from dural tear. Two patients of fusion group suffered from postoperative L5 neurological deficit. One patient of fusion group suffered from acute delirium with no apparent cause identified. There was no postoperative infection which required exploration in both groups.

Conclusion

We conclude that in a particular group of patients with DLS, fenestration of lamina alone offers comparable clinical and functional outcomes as laminectomy with concomitant instrumented fusion.