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Study Design: Retrospective Review.Objective: The aim of this study was to determine medical, radiographic, and surgical risk factors for the development of adjacent segment disease (ASD) after lumbar fusion.Summary Of Background Data: ASD is a recognized outcome of spinal fusion that leads to increased costs and debilitating symptoms for patients. However, a comprehensive understanding of risk factors for the development of this surgical outcome does not exist.Methods: The medical records of patients who received their first lumbar fusion for any indication were retrospectively examined for preoperative medical comorbidities and medications, as well as surgical approach and perioperative complications. A blinded reviewer assessed radiographs for each patient to examine sagittal alignment after fusion. Multivariable logistic regression was used to model the risk of developing ASD on the basis of one or more predictors.Results: A total of 137 patients fit the inclusion criteria; 9% required a follow-up operation for degeneration at segments adjacent to the fusion. The ASD group had a mean follow-up of 21.1 months prior to revision surgery and an overall follow-up of 41.0 months. The average follow-up in the control group was 14.0 months. Statistically significant independent predictors of developing ASD included antidepressant use [odds ratio (OR) = 5.4], diagnosis of degenerative scoliosis (OR = 34.2), fusion of L4-S1 (OR = 56.5), having no decompressions adjacent to the fusion, and low sacral slope (OR = 0.9). No patient who developed ASD received a decompression adjacent to the fusion such that an OR could not be generated for this independent predictor.Conclusion: This study is the first to use a combination of medical, surgical, and postoperative sagittal balance as risk factors for the development of adjacent segment disease after lumbar fusion. The awareness of these risk factors may allow for better patient selection and surgical technique to decrease the probability of acquiring this adverse outcome.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Study Design. Systematic review. Objective. To evaluate literature comparing fusion rates in anterior lumbar interbody fusion (ALIF), posterior lumbar interbody/transforaminal lumbar interbody fusion (PLIF/TLIF), and posterolateral lumbar fusion (PLF) with and without recombinant human bone morphogenetic protein-2 (rhBMP-2). Summary of Background Data. rhBMP-2 is used for the FDA-approved indication of single-level ALIF with LT-Cage and off-label for PLIF/TLIF, and PLF. Due to recent controversies, it is essential to evaluate the literature for its effects on fusion rates to evaluate whether benefits outweigh potential complications. Methods. A Medline search was performed of clinical studies published between May 2000 and May 2012 comparing fusion rates after ALIF, PLIF/TLIF, and PLF surgery with versus without rhBMP-2. Only studies with a control arm were reviewed. Results. 16 studies were reviewed (1794 patients, 995 treated with rhBMP-2 and 799 without). 5 of 5 studies for PLIF/TLIF (including 301 of 301 patients), 1 of 4 for ALIF (including 279 of 589 patients), and 3 of 7 for PLF (including 272 of 904 patients) reported no significant improvement in fusion rates with rhBMP-2 compared with those without rhBMP-2 at longest follow-up investigated. Average fusion rate 24 months after surgery was 97.8% for ALIF (n = 316), 95.7% for PLIF/TLIF (n = 141), and 93.6% for PLF (n = 422) with rhBMP-2 and 88.2% (n =228), 89.5% (n =86), and 83.1% (n =372) without rhBMP-2, for ALIF, PLIF/TLIF, and PLF, respectively. Odds ratio of fusion were calculated as 7.08 (95% CI: 1.54-32.7) in ALIF, 1.98 (95% CI: 0.39-10.1) in PLIF/TLIF, and 3.06 (95% CI: 1.61-5.80) in PLF with rhBMP-2 as compared with without rhBMP-2. Conclusion. Although numerous studies did not show statistically significant improvement in fusion rates with rhBMP-2 use, analysis of combined studies revealed significant improvement in fusion rate with rhBMP-2 in ALIF and PLF patients. Notably, even when pooling data from several studies, rhBMP-2 did not result in statistically significantly improved fusion rates in PLIF/TLIF. However, heterogeneity of rhBMP-2 dosing, surgical techniques, and quality of papers reviewed may limit the validity of conclusions drawn. [ABSTRACT FROM AUTHOR]