Cost-Effectiveness of Minimally Invasive Tubular vs. Open Laminectomy for Pure Lumbar Spinal Stenosis: A Markov State-Transition Analysis.

Study DesignDecision-analytic cost-effectiveness analysis using a Markov state-transition model.IntroductionLumbar spinal stenosis (LSS) is the most common indication for spine surgery in older adults. Minimally invasive surgery (MIS) tubular decompression and open laminectomy produce equivalent one-year outcomes, but their long-term cost-effectiveness for pure decompression is unknown. We modeled 10-year cost-effectiveness from the U.S. payer perspective.MethodsWe built a five-state Markov model for a simulated cohort of 10,000 patients aged 65 with pure LSS (no instability, deformity, spondylolisthesis, or prior surgery), using 3-month cycles, a 10-year horizon, and 3% annual discounting. QALYs used SPORT EQ-5D utilities. Perioperative complication rates came from the Nerland 2015 propensity-matched cohort (10.6% vs. 14.6%; risk difference 4.1 percentage points, 95% CI -2.6 to 10.7). Recurrence, postoperative utility, and perioperative mortality were equalized across arms. One-way, threshold, and probabilistic sensitivity analyses (PSA) were performed, including wide-uncertainty sampling of the complication difference across its confidence interval.ResultsMIS yielded 5.95 QALYs at $26,283 versus 5.91 QALYs at $30,450 for open laminectomy, saving $4,167 per patient (MIS dominant). MIS was cost-effective in 81% of PSA iterations at $50,000/QALY and in 82% to 88% under wide-uncertainty sampling, and remained cost-effective at $100,000/QALY unless its complication rate exceeded 17.5%. Without any complication advantage, MIS still saved $3,454 with equal QALYs.ConclusionFor pure LSS, MIS tubular decompression was cost-effective and, in the base case, dominant over open laminectomy. The advantage reflects the complication difference and the lower index cost, and should inform rather than determine coverage policy.