Title : Impact of preoperative pelvic balance on revision surgery rates in Degenerative Lumbar Spondylolisthesis (DLS): A multicenter prospective study
Abstract:
Objectives: Degenerative Lumbar Spondylolisthesis (DLS) is a debilitating condition often treated surgically. Patient balance is linked to functional outcomes, with worse results in those with pelvic tilt-lumbar mismatch or forward flexed postures. This study examines the association between revision surgery and global radiographic alignment pre- and postoperatively. Secondary aims include assessing whether fusion surgery affects revision rates by altering spinal balance.
Methods: Patients prospectively enrolled from eleven tertiary care institutions (2019 to 2025) within the Canadian Spine Outcomes and Research Network (CSORN). All had DLS and underwent decompression or fusion. Global and regional radiographic alignment parameters – including spine balance (Sagittal Vertical Axis (SVA)), pelvic incidence, and Lumbar Lordosis (LL) – were measured at baseline, one year, and two years post operatively. Logistic regression models including uni- and multivariate analyses, assessed associations between radiographic parameters, revision surgery, and patient-reported functional outcomes, adjusting for potential baseline confounding factors.
Results: Three-hundred eleven patients were included – 272 patients with no reoperation (87.4%) and 39 with a reoperation (12.6%). Reoperation patients were younger (64.8 ± 9.3 vs. 66.5 ± 9.4, p = 0.169), more often female (65.6% vs 60.4%, p = 0.498), and had worse baseline function (ODI: 48.7 ± 14.3 vs. 43.6 ± 14.7, p=0.010). They reported more back pain (7.5± 1.6 vs. 6.8± 2.3, p=0.012) but lower-grade spondylolisthesis (15.9% vs. 28.2%, p=0.036). At two years, reoperation patients had higher PI-LL mismatch (14.1 vs. 8.3, p=0.009). At twelve months postoperatively, mismatch improvement was greater in non-reoperation (58.9% vs. 44%, p=0.048).
Conclusion: Baseline pelvic balance significantly impacts revision rates in DLS surgery. Reoperation patients demonstrated less improvement in PI-LL mismatch postoperatively. Future efforts should focus on re-establishing better spinal balance when fusion surgery is performed. Given a subset of patients are at higher risk of reoperation, surgeons should integrate risk stratification into preoperative discussions.
