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Background Posterior atlantoaxial fusion is an important armamentarium for neurosurgeons to treat several pathologies involving the craniovertebral junction. Although the potential advantages of recombinant human bone morphogenetic protein-2 (rhBMP-2) are well documented in the lumbar spine, its indication for C1-C2 fusion has not been well characterized. In our institution, we apply rhBMP-2 to the C1-C2 joint either alone or with hydroxyapatite, locally harvested autograft chips, and/or morselized allogenic bone graft for selected cases—without conventional posterior structural bone graft. We report the clinical outcomes of the surgical technique to elucidate its feasibility. Methods We performed a single-center, retrospective review of data from 2008 to 2016 and identified 69 patients who had undergone posterior atlantoaxial fusion with rhBMP-2. The clinical records of these patients were reviewed, and the baseline characteristics, operative data, and postoperative complications were collected and statistically analyzed. Results The average age of the 69 patients was 60.8 ± 4.5 years, and 55.1% were women. With an average follow-up period of 21.1 ± 4.2 months, the C1-C2 fusion rate was 94.3% (65 of 69), and the average time to fusion was 11.4 ± 2.6 months (range, 5–23). The overall reoperation rate was 10.1% (7 of 69), with instrumentation failure in 7 patients (10.1%), adjacent segment disease in 2 (2.9%), and postoperative dysphagia and dyspnea in 2 patients (2.9%). No ectopic bone formation or soft tissue edema developed. Conclusions Although retrospective and from a single center, our study has shown that rhBMP-2 usage at the C1-C2 joint without posterior structural bone grafting is a safe and reasonable surgical option. [ABSTRACT FROM AUTHOR]

BACKGROUND CONTEXT The surgical management of deformity, degenerative pathology, neoplasms, trauma and infection in the lumbosacropelvic spine remains a challenge due to high mechanical demand around this area, risks of pseudarthrosis, and invasive nature of the procedures. To date, two instrumentation techniques are primarily available: iliac screws (ISs) and S2-alar-iliac (S2AI) screws. Previous articles demonstrated lower rates of complications with S2AI screws as compared to ISs; however, none of them have focused on elderly patients who may harbor significant comorbidities, and as such, require more meticulous perioperative management, given these invasive and lengthy procedures. PURPOSE To report safety profile of S2AI in patients over 60 and address differences between S2AI screws and ISs. STUDY DESIGN/SETTING Single-center, retrospective, case-control study. PATIENT SAMPLE Single center, retrospective cohort who underwent lumbosacropelvic fixation with more than two-year follow-up. OUTCOME MEASURES Rates of complications such as mortality, unplanned reoperation, cardiorespiratory complications, transfusion-related complications and functional outcome measures such as visual analogue scale for back pain. METHODS Between October 2010, and December 2014, 171 sacropelvic fusion procedures with IS or S2AI screw instrumentation were performed in 161 patients. The inclusion criteria for this study were as follows: (1) patients over 60years old and (2) patients with more than two-year follow-up periods, which yielded 15 patients (IS) and 41 cases (S2AI), respectively. Rates of complications such as mortality, unplanned reoperation, pseudoarthrosis, cardiorespiratory complications, transfusion-related complications and functional outcome measures such as visual analogue scale for back pain and ambulatory status were collected and statistically analyzed. Intergroup comparison of binary variables was performed via Fisher's exact test. Intergroup comparison of continuous variables was achieved using unpaired t-tests. For the analyses on pain and functional outcomes, the perioperative comparisons for each group and intergroup comparisons were conducted using the Wilcoxon signed-rank test and the Mann–Whitney U test, respectively. All reported p values are 2-sided and p values <.05 were regarded as statistically significant. RESULTS Baseline characteristics such as age, sex, smoking history, diagnoses and comorbidities were similar in both groups. The S2AI group had lower rates of reoperation (19.5% vs 66.6%, p=.002), surgical site infection (0% vs. 16.0%, p<.001), wound dehiscence (0.0% vs. 20.0%, p<.001) and postoperative hyperkalemia (17.7% vs. 43.8%, p=.04) and had lower volume of estimated blood loss (EBL) [ml] (1817.5vs. 2775.6, p=.01) and transfused red blood cell units (4.6vs. 8.0, p=.001) than the IS group, while rates of mortality, L5-S1 pseudarthrosis, and other cardiorespiratory complications were similar in both groups. Pain relief and functional recovery were achieved in both groups without any significant intergroup differences. On multivariate analyses, use of S2AI screws over ISs, smoking, and operated levels were independent predictors of volume of transfusion. CONCLUSIONS Use of S2AI screws over ISs in the elderly was associated with lower rates of reoperation, surgical site infection, wound dehiscence and lower volume of EBL and RBC transfusion, while achieving similar clinical and functional outcomes. [ABSTRACT FROM AUTHOR]

BACKGROUND CONTEXT Occipitocervical fusion is the gold standard stabilization method for several pathologies involving craniovertebral junctions, including basilar invagination, atlantoaxial trauma and neoplasm. However, its postoperative clinical course is oftentimes complicated by dysphagia and dyspnea, presumably due to loss of mobility across occiput-C1-C2 joints, which could lead to aspiration pneumonia and acute airway obstruction, respectively, and are life-threatening complications in this procedure. The exact mechanism and its predictors still remain widely unstudied, but a previous article involving healthy volunteers elaborated on the importance of the occipital and external acoustic meatus to axis angle (O-EAa, "the angle formed by the McGregor line and the line connecting the external acoustic meatus and the midpoint of the inferior end plate of C2"), when predicting the narrowest oropharyngeal airway space (nPAS, "the narrowest anterior–posterior distance from the posterior pharyngeal wall to the back of the tongue between the levels of the uvula tip and the epiglottis tip") on X-rays, which theoretically should directly correlate with postoperative dysphagia. Here, we aimed to evaluate whether pre- and postoperative radiographical measurements such as O-EAa and nPAS could predict postoperative dysphagia in adult patients who underwent occipitocervical fusion procedures. PURPOSE To identify predictors of postoperative dysphagia in patients with adult occiptocervical fusion surgery. STUDY DESIGN/SETTING Retrospective, single-center. PATIENT SAMPLE Patients who underwent occipitocervical fusion at a single institution. OUTCOME MEASURES Prolonged postoperative dysphagia (more than 30 days). METHODS Single-center, retrospective data review from 2010 to 2016 identified 57 patients who underwent spine surgery involving occipitocervical fusion procedures. Among those, 51 patients had more than one-year follow-up as well as an adequate postoperative assessment of swallowing functions. Clinical records of those 51 patients (average age: 53.3, female: 54%) were collected and statistically analyzed. A total of 16 patients (31.4%, group (A)) were diagnosed with postoperative dysphagia associated with occipitocervical fusion, who were compared with 35 patients without this complication (group (B)) in terms of baseline characteristics, operative data and radiographical findings including perioperative O-EAa and nPAS at patients' neutral positions. Intergroup comparison of binary variables was performed via Fisher's exact test. Intergroup comparison of continuous variables was achieved using unpaired t -tests. ROC curves were drawn to evaluate the diagnostic value of O-EAa and nPAS for postoperative dysphagia. Furthermore, the Pearson's correlation was assessed between O-EAa and nPAS. Finally, a multilinear regression model was created to identify factors influencing nPAS. All reported p values are two-sided and p values <.05 were regarded as statistically significant. RESULTS There were no statistically significant difference in terms of baseline characteristics including age, sex, BMI, smoking and comorbidities or operative data such as estimated blood loss, operative time and operated levels. While preoperative O-EAa and nPAS were similar between the two groups (P=.39 and.55, respectively), postoperative O-EAa ((A) 89.3° versus (B) 104.5°, p<.01) and nPAS ((A) 9.9 mm versus (B) 13.6 mm, P=.01) as well as perioperative changes in O-EAa ((dO-EAa), (A) −4.1° vs. (B) 0.6°, P=.01) and nPAS (dnPAS, (A) −2.0 mm vs. (B) 0.2 mm, P=.01) were significantly different. The cut-off value of dOEA-a <−2.4° to predict postoperative dysphasia yielded sensitivity of 81.8% and specificity of 100% (AUC=0.939), which was comparable to dnPAS >−1.1 (sensitivity 81.8%, specificity 100%). The Pearson's correlation coefficient between these two parameters were 0.747 (p<.001). In a linear regression analysis, nPAS (mm) was found to be affected by O-EAa (estimate=0.2, P=.04) and sex (estimate=−4.8 (female=1), P=.03), but not by BMI in this model (R square=0.42). CONCLUSIONS Perioperative changes in O-EAa and nPAS were associated with postoperative dysphagia. Intraoperatively, O-EAa measurement on fluoroscopic images could be utilized as a surrogate marker for nPAS, thereby potentially allowing us to decrease the risk of this crucial complication. These data may prompt multicenter, prospective studies to further validate them and translate them into better patient care in the future. [ABSTRACT FROM AUTHOR]