Friday, September 28, 2018 3:00 PM–4:00 PM abstracts: spinal deformity analysis: 224. Patients with osteoporosis undergoing deformity correction spinal fusion for adult spinal deformity are at greater risk of developing proximal junctional kyphosis

BACKGROUND CONTEXT Osteoporosis is a significant comorbidity that can increase the risk, technical difficulty, and outcomes following spine surgery. Surgical treatment for adult spinal deformity may reliably lead to improvement in radiographical and clinical outcomes. However, proximal junctional kyphosis (PJK) remains a common complication after long instrumented spinal fusion surgery and may occur more often in osteoporotic patients. PURPOSE The goal of this study was to compare patients diagnosed with osteoporosis to nonosteoporotic patients and evaluate the occurrence of PJK following deformity correction spine fusion surgery for adult spinal deformity. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE Consecutive patients who underwent elective posterior spinal fusion for adult deformity at a single academic institution from 2008 to 2014 with a minimum of 2 years of follow-up were identified. Patients were considered osteoporotic if their bone mineral density (BMD) score revealed T OUTCOME MEASURES Radiographic assessments included: sagittal vertical axis (SVA), pelvic incidence (PI), lumbar lordosis (LL), thoracic kyphosis (TK), T1 pelvic angle (TPA), and kyphosis at one- and two-levels above the upper instrumented vertebra (UIV+1, UIV+2). At two levels above the upper instrumented vertebra (UIV+2), kyphosis greater than 10° and more than a 10° increase from the preoperative film was defined as PJK. At UIV+1, PJK was defined as a greater than 15° increase from the preoperative film Multivariate logistic regression was used to test the association between osteoporosis and development of PJK while controlling for differences in patient and operative characteristics. METHODS Multivariate logistic regression was used to test the association between osteoporosis and development of PJK while controlling for differences in patient and operative characteristics. RESULTS A total of 214 patients fulfilled inclusion criteria. Average follow up was (52.8±29.1 months). Patients with osteoporosis were older (64.7+/−12.6 years vs. 56.7 +/−8.6 years; p CONCLUSIONS Patients diagnosed with osteoporosis may be at risk for developing PJK following deformity-correction spine fusion for adult spinal deformity compared to those with more robust bone mineral density. These concerns and the effect on sagittal alignment, and ultimate health-related quality of life, provide additional support towards the importance of preoperative bone mineral density optimization and expectations prior to surgery.