ABSTRACT: Retrospective review of a prospectively collected multi-institutional database.In the present analysis, we investigate the impact of incidental durotomy on outcome in patients undergoing surgery for lumbar degenerative spondylolisthesis.Surgery for lumbar degenerative spondylolisthesis has several potential complications, one of the most common of which is incidental durotomy. The effect of incidental durotomy on outcome, however, remains uncertain.Spine Patient Outcomes Research Trial cohort participants with a confirmed diagnosis of lumbar degenerative spondylolisthesis undergoing standard first-time open decompressive laminectomy, with or without fusion, were followed from baseline at 6 weeks, at 3, 6, 12 months, and yearly thereafter, at 13 spine clinics in 11 US states. Patient data from this prospectively gathered database were reviewed. As of May 2009, the mean (standard deviation [SD]) follow-up among all analyzed degenerative spondylolisthesis patients was 46.6 months (SD = 13.1) (no durotomy: 46.7 vs. had durotomy: 45.2, P = 0.49). The median (range) follow-up time among all analyzed degenerative spondylolisthesis patients was 47.6 months (SD = 2.5-84).A 10.5% incidence of durotomy was detected among the 389 patients undergoing surgery. No significant differences were observed with or without durotomy in age, race, the prevalence of smoking, diabetes and hypertension, decompression level, number of levels, or whether a fusion was performed. There were no differences in incidence of nerve root injury, postoperative mortality, additional surgeries, 36-Item Short Form Health Survey (SF-36) scores of body pain or physical function, or Oswestry Disability Index at 1, 2, 3, and 4 years.Incidental durotomy during first-time surgery for lumbar degenerative spondylolisthesis does not appear to impact outcome in affected patients.