Lumbar Stiffness After Pan-Lumbar Arthrodesis Adversely Affects Patient-Reported Outcomes But does not Compromise Patient Satisfaction in Adult Spinal Deformity

Study design. Retrospective study Objectives. To investigate the effect of lumbar stiffness on patient-reported outcomes (PROs) and satisfaction in patients undergoing adult spinal deformity (ASD) surgery. Summary of background data. Lumbar stiffness following pan-lumbar arthrodesis may impair the activities of daily living. However, the effect lumbar stiffness on the PROs and patient satisfaction in Asian populations remains unclear. Methods. Patients who underwent ≥ 5-level fusion including the sacrum were selected for the study. Radiographic and clinical outcomes were evaluated at postoperative 2 years. Lumbar stiffness was evaluated using the modified lumbar stiffness disability index (M-LSDI), which comprises 10 questionnaires with higher scores indicating greater disability. The PRO measures included the visual analog scale (VAS), Oswestry Disability Index (ODI), Scoliosis Research Socitey-22 (SRS-22), Short Form-36 (SF-36) physical component score (PCS), and SF-36 mental component score (MCS). Patients were divided into two groups based on their 2-year SRS-22 satisfaction scores: high satisfaction (≥ 4.0) and low satisfaction (< 4.0). Results. A total of 194 patients were included in the study (female, 87.6%; mean age, 69.1 years; and mean fusion length, 8.0). All PROs significantly improved after surgery with regard to VAS, ODI, SRS-22, and SF-36. The M-LSDI score was worsened significantly from 22.3 preoperatively to 26.6 postoperatively. Correlation analysis showed that the 2-year M-LSDI scores were negatively associated PRO measures, including VAS, ODI, SRS-22, SF-36 PCS, and SF-36 MCS. Multivariate regression analysis revealed that the 2-year M-LSDI score did not affect patient satisfaction status; the 2-year SRS-22 score was an independent factor for high satisfaction. Conclusions. After surgery, significant improvements were observed in all RROs. Although the postoperative increase in M-LSDI scores were significant, the changes were small. The degree of lumbar stiffness negatively influenced all PRO measures but did not affect patient satisfaction at 2 years postoperatively.