Is Sacral Extension a Risk Factor for Early Proximal Junctional Kyphosis in Adult Spinal Deformity Surgery?

Study designRetrospective cohort study.PurposeTo investigate the role of sacral extension (SE) for the development of proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) surgery.Overview of literatureThe development of PJK is multifactorial and different risk factors have been identified. Of these, there is some evidence that SE also affects the development of PJK, but data are insufficient.MethodsUsing a combined database comprising two propensity-matched groups of fusions following ASD surgery, one with fixation to S1 or S1 and the ilium (SE) and one without SE but with a lower instrumented vertebra of L5 or higher (lumbar fixation, LF), PJK and the role of further parameters were analyzed. The propensity-matched variables included age, the upper-most instrumented vertebra (UIV), preoperative sagittal alignment, and the baseline to one year change of the sagittal alignment.ResultsPropensity matching led to two groups of 89 patients each. The UIV, pelvic incidence minus lumbar lordosis, sagittal vertical axis, pelvic tilt, age, and body mass index were similar in both groups (p >0.05). The incidence of PJK at postoperative one year was similar for SE (30.3%) and LF (22.5%) groups (p =0.207). The PJK angle was comparable (p =0.963) with a change of -8.2° (SE) and -8.3° (LF) from the preoperative measures (p =0.954). A higher rate of PJK after SE (p =0.026) was found only in the subgroup of patients with UIV levels between T9 and T12.ConclusionsInstrumentation to the sacrum with or without iliac extension did not increase the overall risk of PJK. However, an increased risk for PJK was found after SE with UIV levels between T9 and T12

GRACE/SUSY Automatic Generation of Tree Amplitudes in the Minimal Supersymmetric Standard Model

GRACE/SUSY is a program package for generating the tree-level amplitude and evaluating the corresponding cross section of processes of the minimal supersymmetric extension of the standard model (MSSM). The Higgs potential adopted in the system, however, is assumed to have a more general form indicated by the two-Higgs-doublet model. This system is an extension of GRACE for the standard model(SM) of the electroweak and strong interactions. For a given MSSM process the Feynman graphs and amplitudes at tree-level are automatically created. The Monte-Carlo phase space integration by means of BASES gives the total and differential cross sections. When combined with SPRING, an event generator, the program package provides us with the simulation of the SUSY particle productions.Comment: 39 page, 1 figur

Cervical Deformity Patients Have Baseline Swallowing Dysfunction but Surgery Does Not Increase Dysphagia at 3 Months: Results From a Prospective Cohort Study.

Study designProspective cohort study.ObjectivesMost studies of dysphagia in the cervical spine have focused on a degenerative patient population; the rate of dysphagia following surgery for cervical deformity (CD) is unknown. This study aims to investigate if surgery for cervical deformity results in postoperative dysphagia.MethodsPatients with CD undergoing surgery from 2013 to 2015 were prospectively enrolled to evaluate dysphagia. Demographic, operative, and radiographic variables were analyzed. The Quality of Life in Swallowing Disorders (SWAL-QoL) was used to measure dysphagia. Paired t test, independent t tests, and bivariate Pearson correlations were performed.ResultsA total of 88 CD patients, aged 61.52 ± 10.52 years, were enrolled. All patients (100%) had 3-month SWAL-QoL for analysis. The baseline preoperative SWAL-QoL was 78.35. This is roughly the same level of dysphagia as an anterior cervical discectomy patient that is 3 weeks removed from surgery. Increasing body mass index (BMI) was correlated with decreased SWAL-QoL score (r = -0.30, P = .001). Age, gender, smoking, and Charlson Comorbidity Index (CCI) showed no significant correlations with preoperative SWAL-QoL. Patients with prior cervical surgery had a lower preoperative SWAL-QoL (P = .04). While 11 patients had acute postoperative dysphagia, CD surgery did not result in lower SWAL-QoL at 3 months (77.26 vs 78.35, P = .53). Surgical variables, including estimated blood loss (EBL), anterior or posterior fusion levels, steroid use, preoperative traction, staged surgery, surgical approach, anterior corpectomy, posterior osteotomy, and UIV (upper instrumented vertebrae) location, showed no impact on postoperative SWAL-QoL. Correction of cervical kyphosis was not correlated to 3-month SWAL-QoL scores or the change in SWAL-QoL scores.ConclusionsWhile patients undergoing surgery for cervical deformity had swallowing dysfunction at baseline, we did not observe a significant decline in SWAL-QoL scores at 3 months. Patients with prior cervical surgery and higher BMI had a lower baseline SWAL-QoL. There were no surgical or radiographic variables correlated to a change in SWAL-QOL score

The posterior use of BMP-2 in cervical deformity surgery does not result in increased early complications: A prospective multicenter study

Study designProspective cohort study.ObjectivesTo describe the rate of short-term complications following the posterior use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in cervical deformity (CD) surgery.MethodsCD patients from 2013 to 2015 were enrolled in a prospective, multicenter database. Patients were divided into those receiving rhBMP-2 (BMP) and no rhBMP-2 (NOBMP). The relationship between BMP use, demographic variables surgical variables, radiographic parameters and complications was evaluated.ResultsA total of 100 patients (47 BMP, 53 NOBMP) were included. Follow-up time averaged 7.6 months (range 3-12 months). An average of 13.6mg of BMP was used per person with 1.49 mg per level. Compared with the NOBMP group, patients in the BMP group were older (P = .03). BMP was more commonly used in patients that and had longer prior fusions (6.0 vs 2.5, P < .01). There were no differences between groups with regards to a history of surgery, Charlson Comorbidity Index, estimated blood loss, operation time, fusion levels, and surgical approach. The maintenance of radiographic parameters at 6-month follow-up was similar. There were no differences in terms of total complication incidence, total complications per person, major complications per person or any specific complication. Linear regression and Pearson correlation analysis did not reveal any strong r2 values (r2 = 0.09, 0.08, 0.06) between the use of BMP and complications (major or operative).ConclusionsBMP use was not directly associated with an increased incidence of early complications in this prospective cohort of operative adult CD patients. Its use was associated with increased number of levels instrumented and fused

The cytoplasmic tail of the rabies virus G protein is an essential domain controlling death/survival in human neuronal cells

Poster presentation

Cervical, Thoracic, and Spinopelvic Compensation After Proximal Junctional Kyphosis (PJK): Does Location of PJK Matter?

Study Design:Retrospective case series. Objective:Compensatory changes above a proximal junctional kyphosis (PJK) have not been defined. Understanding these mechanisms may help determine optimal level selection when performing revision for PJK. This study investigates how varying PJK location changes proximal spinal alignment. Methods:Patients were grouped by upper instrumented vertebrae (UIV): lower thoracic (LT; T8-L1) or upper thoracic (UT; T1-7). Alignment parameters were compared. Correlation analysis was performed between PJK magnitude and global/cervical alignment. Results:A total of 369 patients were included; mean age of 63 years, body mass index 28, and 81% female, LT (n = 193) versus UT (n = 176). The rate of radiographic PJK was 49%, higher in the LT group (55% vs 42%, P = .01). The UT group displayed significant differences in all cervical radiographic parameters (P < .05) between PJK versus non-PJK patients, while the LT group displayed significant differences in T1S and C2-T3 sagittal vertical axis (SVA) (CTS). In comparing UT versus LT patients, UT had more posterior global alignment (smaller TPA [T1 pelvic angle], SVA, and larger PT [pelvic tilt]) and larger anterior cervical alignment (greater cSVA [cervical SVA], T1S-CL [T1 slope-cervical lordosis] mismatch, CTS) compared to LT. Correlation analysis of PJK magnitude and location demonstrated a correlation with increases in CL, T1S, and CTS in the UT group. In the LT group, PT increased with PJK angle (r = 0.17) and no significant correlations were noted to SVA, cSVA, or T1S-CL. Conclusions:PJK location influences compensation mechanisms of the cervical and thoracic spine. LT PJK results in increased PT and CL with decreased CTS. UT PJK increases CL to counter increases in T1S with continued T1S-CL mismatch and elevated cSVA

Clinically Significant Thromboembolic Disease in Adult Spinal Deformity Surgery: Incidence and Risk Factors in 737 Patients.

Study Design:Retrospective cohort study. Objectives:Describe the rate and risk factors for venous thromboembolic events (VTEs; defined as deep venous thrombosis [DVT] and/or pulmonary embolism [PE]) in adult spinal deformity (ASD) surgery. Methods:ASD patients with VTE were identified in a prospective, multicenter database. Complications, revision, and mortality rate were examined. Patient demographics, operative details, and radiographic and clinical outcomes were compared with a non-VTE group. Multivariate binary regression model was used to identify predictors of VTE. Results:A total of 737 patients were identified, 32 (4.3%) had VTE (DVT = 14; PE = 18). At baseline, VTE patients were less likely to be employed in jobs requiring physical labor (59.4% vs 79.7%, P < .01) and more likely to have osteoporosis (29% vs 15.1%, P = .037) and liver disease (6.5% vs 1.4%, P = .027). Patients with VTE had a larger preoperative sagittal vertical axis (SVA; 93 mm vs 55 mm, P < .01) and underwent larger SVA corrections. VTE was associated with a combined anterior/posterior approach (45% vs 25%, P = .028). VTE patients had a longer hospital stay (10 vs 7 days, P < .05) and higher mortality rate (6.3% vs 0.7%, P < .01). Multivariate analysis demonstrated osteoporosis, lack of physical labor, and increased SVA correction were independent predictors of VTE (r2 = .11, area under the curve = 0.74, P < .05). Conclusions:The incidence of VTE in ASD is 4.3% with a DVT rate of 1.9% and PE rate of 2.4%. Osteoporosis, lack of physical labor, and increased SVA correction were independent predictors of VTE. Patients with VTE had a higher mortality rate compared with non-VTE patients

Historia poblacional y análisis antropogenético de la ciudad de Salta

In the present study, the genetic composition of Salta capital city was estimated in a population sample. A total of 223 non-related​ blood-donors from the Centro Privado de Hemoterapia were included, who provided written informed consent and genealogical information. Twelve autosomal markers, GM allotypes, mtDNA and Y-chromosome continental origin were analysed; genetic admixture was estimated employing the ADMIX program. Autosomal markers show the presence of 50,02% for the Amerindian component, 46,29% for the European and 3,51% for the African component. Amerindians mitochondrial haplogroups represented a 93,75%, while the Europeans haplogroups represented a 3,85% and the Africans a 2,40%; 17,1% of males analysed exhibited the aboriginal variant Q*M3. The data were compared to those obtained previously in other cities, and the genetic admixture of Salta showed the highest values of Amerindian and African component. The intraregional immigration is much more remarkable than interregional or foreign immigration. These studies reinforce the idea that the Argentine population should not be considered as a homogeneus totality but variability must be taken into account

The Health Impact of Symptomatic Adult Spinal Deformity: Comparison of Deformity Types to United States Population Norms and Chronic Diseases.

Study designA retrospective analysis of a prospective, multicenter database.ObjectiveThe aim of this study was to evaluate the health impact of symptomatic adult spinal deformity (SASD) by comparing Standard Form Version 2 (SF-36) scores for SASD with United States normative and chronic disease values.Summary of background dataRecent data have identified radiographic parameters correlating with poor health-related quality of life for SASD. Disability comparisons between SASD patients and patients with chronic diseases may provide further insight to the disease burden caused by SASD.MethodsConsecutive SASD patients, with no history of spine surgery, were enrolled into a multicenter database and evaluated for type and severity of spinal deformity. Baseline SF-36 physical component summary (PCS) and mental component summary (MCS) values for SASD patients were compared with reported U.S. normative and chronic disease SF-36 scores. SF-36 scores were reported as normative-based scores (NBS) and evaluated for minimally clinical important difference (MCID).ResultsBetween 2008 and 2011, 497 SASD patients were prospectively enrolled and evaluated. Mean PCS for all SASD was lower than U.S. total population (ASD = 40.9; US = 50; P < 0.05). Generational decline in PCS for SASD patients with no other reported comorbidities was more rapid than U.S. norms (P < 0.05). PCS worsened with lumbar scoliosis and increasing sagittal vertical axis (SVA). PCS scores for patients with isolated thoracic scoliosis were similar to values reported by individuals with chronic back pain (45.5 vs 45.7, respectively; P > 0.05), whereas patients with lumbar scoliosis combined with severe sagittal malalignment (SVA >10 cm) demonstrated worse PCS scores than values reported by patients with limited use of arms and legs (24.7 vs 29.1, respectively; P < 0.05).ConclusionsSASD is a heterogeneous condition that, depending upon the type and severity of the deformity, can have a debilitating impact on health often exceeding the disability of more recognized chronic diseases. Health care providers must be aware of the types of SASD that correlate with disability to facilitate appropriate diagnosis, treatment, and research efforts.Level of evidence3

Bone biopsy practice patterns across Europe: the European renal osteodystrophy initiative - a position paper

Renal osteodystrophy (ROD) is a heterogeneous group of metabolic bone diseases complicating progressive chronic kidney disease (CKD). Bone biomarkers and bone imaging techniques may help to assess bone health and predict fractures in CKD but do have important inherent limitations. By informing on bone turnover and mineralization, a bone biopsy may help to guide prevention and treatment of ROD and its consequences. According to a recent survey conducted among European nephrologists, bone biopsies are performed rather exceptionally, both for clinical and research purposes. Obviously, clinical research in the field of ROD is threatened by vanishing clinical and pathological expertise, small patient cohorts and scientific isolation. In March 2016, the European Renal Osteodystrophy (EU-ROD) initiative was created under the umbrella of the ERA-EDTA CKD-mineral and bone disorder (MBD) Working Group to revitalize bone biopsy as a clinically useful tool in the diagnostic workup of CKD-MBD and to foster research on the epidemiology, implications and reversibility of ROD. As such, the EU-ROD initiative aims to increase the understanding of ROD and ultimately to improve outcomes in CKD patients