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Background Context: There are several reports regarding pathogeneses and risk factors for proximal junctional kyphosis (PJK) in adult spinal deformity surgery. However, the relationship between thoracolumbar muscle condition and PJK has not been investigated yet.Purpose: We aimed to elucidate the thoracolumbar muscle conditions on the incidence of PJK in adult patients with spinal deformity treated by long instrumented spinal fusion surgery stopping at thoracolumbar junction with a minimum 2-year follow-up (F/U).Study Design: This is a retrospective review of prospective database.Patient Sample: A total of 44 cases of patients having multilevel spinal instrumented fusion stopping at thoracolumbar junction for adult spinal deformity in two academic institutions from 2004 to 2012 were enrolled in this study.Outcome Measures: For clinical outcomes, the Scoliosis Research Society questionnaire-22r (SRS-22r) was used preoperatively and at ultimate F/U.Methods: Inclusion criteria were age >20 and minimum five vertebrae fused from T9 upper instrumented vertebra (UIV) to any lower instrumented vertebra. Radiographic assessment included pelvic parameters, Cobb measurements in the coronal-sagittal plane, and measurements of the thoracolumbar muscularity (cross-sectional area of muscle-vertebral body ratio×100) and fatty degeneration (signal intensity of muscle-subcutaneous fat ratio×100).Results: The prevalence of PJK was 38.6%. Age at surgery, gender, fusions extending to the sacrum, levels fused, combined anterior-posterior surgery, and a UIV level were not significantly different between PJK and non-PJK groups. Lower bone mineral density (BMD; T-score: -2.5 vs. -1.3, p=.003) and lower muscularity and higher fatty degeneration at the level of T10 to L2 (131.8 vs. 159.0, p<.01; 59.0 vs. 44.0, p<.001, respectively) were identified risk factors for PJK. Radiographic parameters demonstrated a higher postoperative lumbar lordosis (LL) change (43.8 vs. 29.3, p<.001) and a larger sagittal vertical axis (SVA) change with surgery (8.4 cm vs. 4.8 cm, p=.01) in those with PJK. Although SRS postop pain scores were inferior in PJK group (3.3 vs. 4.1, p<.05), there were no significant differences in the average scores between the groups (3.5 vs. 3.3, p<.05).Conclusions: Patients with PJK had lower thoracolumbar muscularity and higher fatty degeneration than patients without PJK before surgery. Our data suggest that osteoporosis, large corrections in LL and SVA with surgery, and lower muscularity and higher fatty degeneration at the thoracolumbar area can lead to PJK. [ABSTRACT FROM AUTHOR]

Purpose of study: to evaluate pulmonary function changes 5 years or more prospectively after surgery in patients with adolescent idiopathic scoliosis (AIS) relative to the type of surgical approach used for the spinal arthrodesis (Table 1) Table 1 Postoperative changes in PFTs Group Preoperative FVC/FEV1 3-month PO 1-year PO 2-year PO 5-year PO G1 PSF-IC (n=43) 2.80/2.39 2.86/2.43 2.94/2.46 3.13/2.70 3.26/2.76 G2 PSF-TP (n=39) 2.92/2.39 2.47/2.10 2.74/2.30 3.04/2.56 3.04/2.52 G3 ASF-TC (n=15) 3.09/2.69 2.44/2.39 2.71/2.47 2.96/2.56 2.83/2.42 G4 ASF/PSF (n=12) 2.38/2.00 2.11/1.65 2.33/1.96 2.44/2.09 2.54/2.15 G2 + 3 + 4 (n=66) 2.85/2.41 2.39/2.10 2.64/2.27 2.91/2.47 2.91/2.43 PO = post-op. . Methods used: A total of 109 patients with AIS undergoing surgical treatment were prospectively evaluated with pulmonary function tests (PFTs), forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV 1 ) before surgery, 3 months, 1 year, 2 years and a minimum 5 years after surgery (5 to 14 years). All patients were divided into four groups. Group 1 (n=43) posterior spinal fusion with iliac crest bone graft (PSF-IC); Group 2 (n=39) PSF with thoracoplasty (PSF-TP); Group 3 (n=15) anterior fusion (ASF) with a rib resection thoracotomy (ASF-TC) and Group 4 (n=12) combined ASF and PSF with autogenous rib and iliac crest graft (ASF/PSF). of findings: Irrespective of the surgical approach used for the spinal arthrodesis, postoperative PFTs (absolute values) improved continuously until 2 years after surgery, then did not change between 2- and 5-year follow-up, except Group 1 (PSF-IC), which continued to improve up to 5 years after surgery. Five years after surgery, Group 1 had statistically increased PFTs both in absolute value and percent predicted, whereas patients in Groups 2, 3 and 4 had unchanged (Groups 2 and 4) or significantly decreased (Group 3) pulmonary function values (p<.05). Relationship between findings and existing knowledge: Irrespective of the surgical approach used, postoperative pulmonary function tests (absolute values) increase until 5 years after surgery. Patients who had no chest cage disruption (Group 1) had a significantly greater improvement in their pulmonary function values at 5 years after surgery than patients with chest cage disruption (Groups 2, 3 and 4). Overall significance of findings: We can choose more appropriate approaches for surgical candidates and predict the change of the pulmonary functions 5 years after operation. Disclosures: No disclosures. Conflict of interest: No conflicts. [ABSTRACT FROM AUTHOR]