Optimal patient selection for upper-thoracic (UT) versus lower-thoracic (LT) fusion during adult spinal deformity (ASD) correction is challenging. Radiographic and clinical outcomes following UT versus LT fusion remain incompletely understood. The purposes of this study were: 1) to evaluate demographic, radiographic, and surgical characteristics associated with choice of UT versus LT fusion endpoint; and 2) to evaluate differences in radiographic, clinical, and health-related quality of life (HRQOL) outcomes following UT versus LT fusion for ASD.
Retrospective review of a prospectively collected multicenter ASD database was performed. Patients with ASD who underwent fusion from the sacrum/ilium to the LT (T9–L1) or UT (T1–6) spine were compared for demographic, radiographic, and surgical characteristics. Outcomes including proximal junctional kyphosis (PJK), reoperation, rod fracture, pseudarthrosis, overall complications, 2-year change in alignment parameters, and 2-year HRQOL metrics (Lumbar Stiffness Disability Index, Scoliosis Research Society-22r questionnaire, Oswestry Disability Index) were compared after controlling for confounding factors via multivariate analysis.
Three hundred three patients (169 LT, 134 UT) were evaluated. Independent predictors of UT fusion included greater thoracic kyphosis (odds ratio [OR] 0.97 per degree, p = 0.0098), greater coronal Cobb angle (OR 1.06 per degree, p < 0.0001), and performance of a 3-column osteotomy (3-CO; OR 2.39, p = 0.0351). While associated with longer operative times (ratio 1.13, p < 0.0001) and greater estimated blood loss (ratio 1.31, p = 0.0018), UT fusions resulted in greater sagittal vertical axis improvement (−59.5 vs −41.0 mm, p = 0.0035) and lower PJK rates (OR 0.49, p = 0.0457). No significant differences in postoperative HRQOL measures, reoperation, or overall complication rates were detected between groups (all p > 0.1).
Greater deformity and need for 3-CO increased the likelihood of UT fusion. Despite longer operative times and greater blood loss, UT fusions resulted in better sagittal correction and lower 2-year PJK rates following surgery for ASD. While continued surveillance is necessary, this information may inform patient counseling and surgical decision-making.
ABBREVIATIONS3-CO = 3-column osteotomy; ASA = American Society of Anesthesiologists; ASD = adult spinal deformity; CCI = Charlson Comorbidity Index; EBL = estimated blood loss; HRQOL = health-related quality of life; ISSG = International Spine Study Group; LL = lumbar lordosis; LSDI = Lumbar Stiffness Disability Index; LT = lower thoracic; ODI = Oswestry Disability Index; OR = odds ratio; PI = pelvic incidence; PJA = proximal junction angle; PJF = proximal junctional failure; PJK = proximal junctional kyphosis; PT = pelvic tilt; SRS-22r = Scoliosis Research Society 22-r questionnaire; SVA = sagittal vertical axis; TK = thoracic kyphosis; UIV = upper instrumented vertebra; UT = upper thoracic.
Correspondence Daniel B. C. Reid: Warren Alpert Medical School of Brown University, Providence, RI. firstname.lastname@example.org.INCLUDE WHEN CITING Published online December 20, 2019; DOI: 10.3171/2019.9.SPINE19557.Disclosures Dr. Daniels reports a nonfinancial personal relationship with Stryker, Orthofix, Spineart, EOS, Springer, and Southern Spine. Dr. Passias reports being a consultant for Medicrea and SpineWave, and being on the Scientific Advisory Board, receiving speaking/teaching arrangements, and receiving grants from Terumo BCT, Zimmer Biomet, and the Cervical Spine Research Society. Dr. Lafage reports direct stock ownership in Nemaris Inc.; being a consultant for Globus Medical; receiving royalties from NuVasive; speaking/teaching arrangements with DePuy Synthes Spine/The Permanente Medical Group; serving on the Executive Committee of ISSG; and serving on the editorial board of the European Spine Journal. Dr. Smith reports being a consultant for Zimmer Biomet, K2M/Stryker, NuVasive, AlloSource, and Cerapedics; receiving royalties from Zimmer Biomet and NuVasive; clinical or research support for this study from DePuy Synthes; support of non–study-related clinical or research effort from DePuy Synthes and AOSpine; and fellowship support from NREF and AOSpine. Dr. Shaffrey reports being a consultant for NuVasive, Medtronic, Eos, and Siemens; direct stock ownership in NuVasive; and being a patent holder for NuVasive, Medtronic, and Zimmer Biomet. Dr. Gupta reports being a consultant for DePuy and Medtronic; direct stock ownership in J & J and P & G; receiving royalties, serving on the advisory board, and travel arrangements from DePuy; receiving royalties from Innomed; receiving stock options from perForm Biologics; receiving travel arrangements from Alphatec, SRS, and Medtronic; being on the advisory board of Medtronic; and grants from AOSpine and OMeGA paid directly to the institution for a fellowship. Dr. Klineberg reports being a consultant for DePuy, Stryker, and Medicrea; receiving honoraria from K2M and AOSpine; and receiving a fellowship grant from AOSpine. Dr. Schwab reports being a consultant for Globus Medical, Zimmer Biomet, MSD, and K2M; direct stock ownership in Nemaris Inc; support of non–study-related clinical or research effort from DePuy, K2M, NuVasive, Medtronic, Globus, AlloSource, Orthofix, and SIBone; and speaking/teaching arrangements from Globus Medical, Zimmer Biomet, MSD, and K2M. Dr. Burton reports receiving clinical or research support for this study from Pfizer and DePuy; being a patent holder for DePuy; and being a consultant for Bioventus. Dr. Bess reports being a consultant for K2/Stryker; being a patent holder for K2/Stryker; clinical or research support for this study from ISSGF; and support of non–study-related clinical or research effort from ISSGF. Dr. Ames reports being a consultant for DePuy Synthes, Medtronic, Stryker, Medicrea, K2M, and Biomet Zimmer; receiving royalties from Stryker, Biomet Zimmer Spine, DePuy Synthes, NuVasive, Next Orthosurgical, K2M, and Medicrea; receiving research support from Titan Spine, DePuy Synthes, and ISSG; being on the editorial board of Operative Neurosurgery; receiving grant funding from SRS; being on the Executive Committee of ISSG; and serving as the director of Global Spinal Analytics. Dr. Hart reports being a consultant for Globus, Medtronic, DePuy Synthes, and Orthofix; and receiving royalties from ISSLS.