Short-Term Functional Recovery Trajectories After Adult Spinal Deformity Surgery Differ by Upper Instrumented Vertebra Level.
Academic Article
Overview
abstract
STUDY DESIGN: A retrospective study utilizing a prospectively collected database. OBJECTIVE: To compare postoperative recovery trajectories of disability following adult spinal deformity (ASD) surgery among patients with different upper instrumented vertebra (UIV) selections. SUMMARY OF BACKGROUND DATA: Choosing the UIV is crucial decision making in ASD surgery. The added morbidity by fusing to the upper versus lower thoracic spine remains unknown. MATERIAL AND METHODS: This study involved patients who had primary ASD surgery from UIV at L2 or above to pelvis. The primary outcome measured was the Oswestry Disability Index (ODI), collected longitudinally. Multivariable mixed-effects regression model with restricted cubic splines were used to evaluate recovery trajectories across three UIV locations: upper thoracic (UT=T2-T5), lower thoracic (LT=T9-T12), and upper lumbar (UL=L1-L2). RESULTS: Of 222 patients (UT, 58; LT, 135; UL, 29), preoperative demographics and clinical characteristics differed significantly in age (UT, 62.6 vs. LT, 65.7 vs. UL, 70.3 y, P=0.001), body mass index (UT, 26.2 vs. LT, 26.5 vs. UL, 29.5, P=0.039), length of stay (8.4 vs. 5.4 vs. 5.3 d, P <0.001), and estimated blood loss (UT, 1634 vs. LT, 917 vs. UL, 714 ml; P <0.001). A multivariable model adjusting for background differences suggested that the recovery trajectory significantly differed by UIV groups (P=0.017). UT group exhibited a significantly steeper early postoperative increase in disability, with ODI peaking at 48.7 points on day 55, compared to earlier and lower peaks in the LT (41.5 on day 35) and UL (44.2 on day 30) groups. CONCLUSION: Patients undergoing ASD surgery with UIV fixation in the upper thoracic spine (T2-T5) experience a delayed initial functional recovery compared to those with fixation to the lower thoracic or upper lumbar spine. EVIDENCE LEVEL: Level 3.
