Minimally Invasive Decompression In Focal Lumbar Spinal Stenosis With Or Without Stable Spondylolisthesis - Comparative Outcomes And Re-operation Rates At 2 Yrs And Beyond

Presented at SMISS Annual Forum 2014
By Y. Rampersaud MD, FRCS9(C)
With B Chaudhary , Rohit Amritanand ,

Disclosures: Y. Rampersaud MD, FRCS9(C) Consulting Fees: Medtronic B Chaudhary None, Rohit Amritanand None,

Surgical outcomes for degenerative lumbar spondylolisthesis (DLS) have been historically shown to be better with instrumented fusion & decompression. However with greater utilization of less invasive midline sparing approaches, recent reported series question the need for fusion in selected patients.

The primary objective of the study was to assess surgical & patient reported outcomes following decompression alone in selected patients with DLS compared to those with noDLS.

A single surgeon consecutive series of patients undergoing surgery for lumbar spinal stenosis (LSS) with a minimum of 2 year follow up were assessed as part of an ongoing prospective observational study. Primary outcome measures were Oswestry Disability Index (ODI) scores & re-operation rates. Secondary outcomes were pre & postoperative visual analogue scale (VAS) scores for leg & back pain & satisfaction ratings post surgery. Decompression alone was chosen for patients with neurogenic claudication/ radiculopathy no or tolerable mechanical back pain and no dynamic instability (<5mm of motion). All patients underwent bilateral decompression via a unilateral minimally invasive approach.

157 LSS patients had surgery from Jan.2007 to Jun.2011, 62 with DLS & 95 without DLS. The cohorts were comparable for age (p=0.51) & pre-operative ODI (p=0.74). The DLS cohort had greater proportion of women (p=0.02). There was significant ODI improvement in both cohorts (DLS mean baseline ODI improved from 40 to 23 at 2 years [p < 0.01] & in noDLS from 39 to 26 [p < 0.01]). The change in ODI was comparable in the two cohorts (p=0.18). VAS leg & back scores similarly improved between cohorts (p=0.50 & 0.22, respectively). Satisfaction was also similar in the 2 groups (88% of DLS patients rated their post surgical satisfaction scores as favourable whilst for noDLS patients this was 82% [p=0.56]. In the DLS cohort, 3 patients (6.4%) had a reoperation at a mean of 2.35 years (range 1-3.5 years) with a mean follow-up of 3.06 years (2-4 years). For those without DLS, 5 patients (5.2%) had a reoperation at a mean of 3.29 years (1-6 years) at a mean follow-up of 4.49 years (2-6 years)

Using the aforementioned selection criteria DLS patients undergoing decompression alone have excellent intermediate term results comparable to LSS patients without DLS. For highly selected DLS patients, successful outcomes without a fusion are achievable.