• STUDY DESIGN
    • Retrospective analysis of prospective data from the degenerative spondylolisthesis (DS) arm of the Spine Patient Outcomes Research Trial.
  • OBJECTIVE
    • The aim of this study was to identify risk factors for reoperation in patients treated surgically for DS and compare outcomes between patients who underwent reoperation with nonreoperative patients.
  • SUMMARY OF BACKGROUND DATA
    • Several studies have examined outcomes following surgery for DS, but few have identified risk factors for reoperation.
  • METHODS
    • Analysis included patients with neurogenic claudication (>12 weeks), clinical neurological signs, spinal stenosis, and DS on standing lateral x-rays. Univariate and multivariate analyses were used to investigate patient characteristics and risk factors. Treatment effects (TEs) were calculated and compared between study groups.
  • RESULTS
    • Of 406 patients, 72% underwent instrumented fusion, 21% noninstrumented fusion, and 7% decompression alone. At 8 years, the reoperation rate was 22%, of which 28% occurred within 1 year, 54% within 2 years, 70% within 4 years, and 86% within 6 years. The reasons for reoperation included recurrent stenosis or progressive spondylolisthesis (45%), complications such as hematoma, dehiscence, or infection (36%), or new condition (14%). Reoperative patients were younger (62.2 vs. 65.3, P = 0.008). Significant risk factors were use of antidepressants (P = 0.008, hazard ratio [HR] 2.08) or having no neurogenic claudication upon enrollment (P = 0.02, HR 1.82). Patients who were smokers, diabetics, obese, or on workman's compensation were not at greater risk for reoperation. At 8-year follow-up, scores for SF-36 bodily pain (BP), Oswestry Disability Index, American Academy of Orthopaedic Surgeons/Modems version (ODI), and stenosis frequency index were better in nonreoperative patients. TE favored nonreoperative patients for SF-36 BP, physical function, ODI, Stenosis Bothersomeness Index, and satisfaction with symptoms (P < 0.001).
  • CONCLUSION
    • The incidence of reoperation for patients with DS was 22% 8 years following surgery. Patients with a history of no neurogenic claudication and patients taking antidepressants were more likely to undergo reoperation. Outcome scores and TE were more favorable in nonreoperative patients.
  • LEVEL OF EVIDENCE
    • 2.