213. Patient reported outcomes comparing lumbar laminectomy and fusion versus laminectomy alone in patients with radiographic spinopelvic malalignment in the setting of concomitant lumbar stenosis and spondylolisthesis: a nonrandomized, prospective cohort study

BACKGROUND CONTEXT The importance of spinopelvic harmony (pelvic incidence [PI] = lumbar lordosis [LL] ±10°) is well established. PI-LL discordance correlates with increased degenerative lumbar spondylolisthesis. Recent evidence favors concomitant fusion and decompression for management of lumbar spondylolisthesis. PURPOSE This study assessed whether the addition of fusion to decompression is superior to decompression alone by examining clinical outcomes and patient-reported outcomes (PROs) in patients with pelvic incidence-lumbar lordosis (PILL) mismatch, single-level, degenerative Grade 1 spondylolisthesis and canal stenosis. STUDY DESIGN/SETTING Observational prospective cohort study. PATIENT SAMPLE A total of 352 patients with spinopelvic mismatch, spinal canal stenosis and single-level, degenerative Grade 1 spondylolisthesis undergoing laminectomy alone or laminectomy with fusion at a tertiary care center. OUTCOME MEASURES Postoperative Patient-Reported Outcome Measurement Information System (PROMIS), Global Physical Health (GPH) and Global Mental Health (GMH) scores were primary outcomes. Secondary outcomes included operative complications, PROs at 6 and 12 months postoperatively, and reoperation. METHODS Patients underwent decompression by laminectomy alone or laminectomy and fusion. Radiographs/MRIs assessed stenosis, pelvic incidence, lumbar lordosis, sacral slope, and pelvic tilt. Propensity score matching (PSM) and coarsened exact matching (CEM) created matched cohorts of “cases” (fusion) and “controls” (decompression). Binary comparisons used McNemar test, continuous outcomes used Wilcoxon rank-sum test. RESULTS A total of 190 (54.0%) of 352 patients with high PILL mismatch were treated with decompression and fusion. Those undergoing fusion experienced greater operative blood loss (308.9 vs 203.2 mL, p=0.0005), operative time (233 vs 149 min, p=0.0006) and length of stay (4.75 vs 2.83 months, p < 0.0001) and fewer months of outpatient physical therapy (1.61 vs 3.65 months, p < 0.0001) compared to decompression-only patients. Additionally, postoperative PILL mismatch at 3 months was lower in the fusion group due to increased lumbar lordosis (48.78 vs 39.8°, p < 0.0001). Postoperative PROs demonstrated significant differences with improved GMH and GPH at 5-7 months (GMH:17.61 vs 14.48, p < 0.0001; GPH: 16.24 vs 14.21, p=0.007) and 10-12 months postoperative (GMH: 26.61 vs 20.75, p < 0.0001; GPH: 23.61 vs 18.13, p < 0.0001) and a decreased 2-year readmission rate (12.63% vs 17.89%, p=0.0442). CONCLUSIONS Patients with spinopelvic mismatch were more likely to benefit from fusion and decompression for treatment of single-level, Grade 1 spondylolisthesis with comorbid spinal canal stenosis. Improvement is associated with significantly increased lumbar lordosis from preoperative measures. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. The importance of spinopelvic harmony (pelvic incidence [PI] = lumbar lordosis [LL] ±10°) is well established. PI-LL discordance correlates with increased degenerative lumbar spondylolisthesis. Recent evidence favors concomitant fusion and decompression for management of lumbar spondylolisthesis. This study assessed whether the addition of fusion to decompression is superior to decompression alone by examining clinical outcomes and patient-reported outcomes (PROs) in patients with pelvic incidence-lumbar lordosis (PILL) mismatch, single-level, degenerative Grade 1 spondylolisthesis and canal stenosis. Observational prospective cohort study. A total of 352 patients with spinopelvic mismatch, spinal canal stenosis and single-level, degenerative Grade 1 spondylolisthesis undergoing laminectomy alone or laminectomy with fusion at a tertiary care center. Postoperative Patient-Reported Outcome Measurement Information System (PROMIS), Global Physical Health (GPH) and Global Mental Health (GMH) scores were primary outcomes. Secondary outcomes included operative complications, PROs at 6 and 12 months postoperatively, and reoperation. Patients underwent decompression by laminectomy alone or laminectomy and fusion. Radiographs/MRIs assessed stenosis, pelvic incidence, lumbar lordosis, sacral slope, and pelvic tilt. Propensity score matching (PSM) and coarsened exact matching (CEM) created matched cohorts of “cases” (fusion) and “controls” (decompression). Binary comparisons used McNemar test, continuous outcomes used Wilcoxon rank-sum test. A total of 190 (54.0%) of 352 patients with high PILL mismatch were treated with decompression and fusion. Those undergoing fusion experienced greater operative blood loss (308.9 vs 203.2 mL, p=0.0005), operative time (233 vs 149 min, p=0.0006) and length of stay (4.75 vs 2.83 months, p < 0.0001) and fewer months of outpatient physical therapy (1.61 vs 3.65 months, p < 0.0001) compared to decompression-only patients. Additionally, postoperative PILL mismatch at 3 months was lower in the fusion group due to increased lumbar lordosis (48.78 vs 39.8°, p < 0.0001). Postoperative PROs demonstrated significant differences with improved GMH and GPH at 5-7 months (GMH:17.61 vs 14.48, p < 0.0001; GPH: 16.24 vs 14.21, p=0.007) and 10-12 months postoperative (GMH: 26.61 vs 20.75, p < 0.0001; GPH: 23.61 vs 18.13, p < 0.0001) and a decreased 2-year readmission rate (12.63% vs 17.89%, p=0.0442). Patients with spinopelvic mismatch were more likely to benefit from fusion and decompression for treatment of single-level, Grade 1 spondylolisthesis with comorbid spinal canal stenosis. Improvement is associated with significantly increased lumbar lordosis from preoperative measures.