Stiffness after Pan-Lumbar Arthrodesis for Adult Spinal Deformity Does Not Significantly Impact Patient Functional Status or Satisfaction Irrespective of Proximal Endpoint

STUDY DESIGN.: Prospective, multi-center OBJECTIVE.: To determine if stiffness significantly affects function or satisfaction after pan-lumbar arthrodesis. SUMMARY OF BACKGROUND DATA.: The Lumbar Stiffness Disability Index (LSDI) is a validated measure of the effect of lumbar stiffness on functional activities. Data suggests that patients undergoing fusion of the entire lumbar spine are at greatest risk of functional limitations from stiffness. METHODS.: The LSDI, Short Form 36 (SF-36), Scoliosis Research Society-22 (SRS-22), and Oswestry Disability Index (ODI) were administered pre-operatively and at 2-year minimum follow-up to 103 spinal deformity patients from 11 centers. Patients were separated according to the proximal arthrodesis level; upper thoracic (T2-5) to pelvis (UT-Pelvis) or thoraco-lumbar (T10-T12) to pelvis (TL-Pelvis). Outcome scores were compared using Studentʼs t-test or Tukey-Kramer HSD ANOVA. Regression analysis of final LSDI scores versus SRS-22 Satisfaction scores was performed. RESULTS.: Mean ages, baseline values and final scores of all outcome parameters were statistically equivalent in the 2 groups. Final LSDI scores did not change significantly from baseline in the UT-Pelvis (p?=?0.478) or TL-Pelvis (p?=?0.301) groups. In contrast, highly significant improvements (p?≤?0.0001) from baseline were seen in both groups for other health-related QoL measures. The 2-year Satisfaction scores were statistically equivalent in the 2 groups, and the correlation between final LSDI and Satisfaction scores in the entire cohort was not significant (R?=?0.013, p?=?0.146). CONCLUSIONS.: Patients undergoing pan-lumbar arthrodesis for adult spinal deformity did not experience substantial increases in disability due to stiffness of the low back, although they did report significant improvements in other health-related QoL measures. Further, LSDI scores did not correlate with patient satisfaction. There were no significant differences in perceived stiffness effects whether arthrodesis stopped in the thoracolumbar or upper thoracic regions. We hope these results will be useful to spine surgeons and patients during pre-operative planning and discussions.Level of Evidence: 2