Benchmarking in the SWISSspine Registry: results of 52 Dynardi lumbar total disc replacements compared with the data pool of 431 other lumbar disc prostheses

The SWISSspine registry is the first mandatory registry of its kind in the history of Swiss orthopaedics and it follows the principle of "coverage with evidence development”. Its goal is the generation of evidence for a decision by the Swiss federal office of health about reimbursement of the concerned technologies and treatments by the basic health insurance of Switzerland. Recently, developed and clinically implemented, the Dynardi total disc arthroplasty (TDA) accounted for 10% of the implanted lumbar TDAs in the registry. We compared the outcomes of patients treated with Dynardi to those of the recipients of the other TDAs in the registry. Between March 2005 and October 2009, 483 patients with single-level TDA were documented in the registry. The 52 patients with a single Dynardi lumbar disc prosthesis implanted by two surgeons (CE and OS) were compared to the 431 patients who received one of the other prostheses. Data were collected in a prospective, observational multicenter mode. Surgery, implant, 3-month, 1-year, and 2-year follow-up forms as well as comorbidity, NASS and EQ-5D questionnaires were collected. For statistical analyses, the Wilcoxon signed-rank test and chi-square test were used. Multivariate regression analyses were also performed. Significant and clinically relevant reduction of low back pain and leg pain as well as improvement in quality of life was seen in both groups (P<0.001 postop vs. preop). There were no inter-group differences regarding postoperative pain levels, intraoperative and follow-up complications or revision procedures with a new hospitalization. However, significantly more Dynardi patients achieved a minimum clinically relevant low back pain alleviation of 18 VAS points and a quality of life improvement of 0.25 EQ-5D points. The patients with Dynardi prosthesis showed a similar outcome to patients receiving the other TDAs in terms of postoperative low back and leg pain, complications, and revision procedures. A higher likelihood for achieving a minimum clinically relevant improvement of low back pain and quality of life in Dynardi patients was observed. This difference might be due to the large number of surgeons using other TDAs compared to only two surgeons using the Dynardi TDA, with corresponding variations in patient selection, patient-physician interaction and other factors, which cannot be assessed in a registry stud

Tetra-μ2-oxido-di-μ4-peroxido-tetra­kis[diphenyl­anti­mony(V)] chloro­form disolvate

The title compound, [Sb4(C6H5)8O4(O2)2]·2CHCl3, contains a tetranuclear antimony(V) core, bridged by oxide and peroxide ligands. Two cores form centrosymmetric dimers by intermolecular C—H⋯O contacts. These dimeric units are further connected by chloro­form solvent mol­ecules involved in C—H⋯O and C—H⋯Cl inter­actions into strands along [010]. The five-membered Sb2O3 rings in the Sb4O8 core invariably adopt envelope conformations

A Smooth Model for the String Group

We construct a model for the string group as an infinite-dimensional Lie group. In a second step we extend this model by a contractible Lie group to a Lie 2-group model. To this end we need to establish some facts on the homotopy theory of Lie 2-groups. Moreover, we provide an explicit comparison of string structures for the two models and a uniqueness result for Lie 2-group models.Comment: 32 pages; v2: uniqueness result for 2-group models added (Th. 6.5), typo in title corrected; v3: construction of basic PU(H)-bundle discussed (Rem. 3.9), final version to appear in IMR

Pregnancy-associated plasma protein-A is an independent short-time predictor of mortality in patients on maintenance haemodialysis

Aims Mortality of maintenance haemodialysis (HD) patients is very high due to polymorbidity, mostly from metabolic and cardiovascular disease. In order to identify patients with high risk for life-threatening complications, reliable prognostic markers would be helpful. Pregnancy-associated plasma protein-A (PAPP-A) has been shown to predict cardiovascular events and death in patients with stable coronary artery disease as well as in acute coronary syndrome in patients with normal renal function. It was the aim of this study to evaluate PAPP-A as a marker for death in patients on maintenance HD. Methods and results PAPP-A serum levels were measured in 170 patients participating in the monitor! trial, a prospective dynamic dialysis cohort multicenter study in Switzerland. Patients were followed up for a median time of 17 months after measuring PAPP-A, and evaluated for death of any cause. Survivors and non-survivors were compared with regard to baseline PAPP-A concentrations. A multivariate logistic regression analysis for death was performed including PAPP-A, age, sex, number of comorbidities, dialysis vintage, Kt/V, IL-6, C-reactive protein, parathyroid hormone (PTH), Ca × PO4 product, and total serum cholesterol. A cut-off value for PAPP-A was calculated for discrimination between patients with low and high mortality risk, respectively. A total of 23 deaths occurred during follow-up, equalling an incidence rate of 0.1. Baseline median PAPP-A levels were 40% higher in non-survivors vs. survivors (P = 0.023). In a multivariate analysis, only PAPP-A, age, and Ca × PO4 product were independent predictors of mortality. A cut-off value of 24 mIU/L discriminates significantly (P = 0.015) between patients at low or high risk for death with a negative predictive value of 91%. Conclusion PAPP-A is a novel and independent short-time predictor of mortality in a maintenance HD population. The pathogenetic relevance of PAPP-A, particularly in the development of cardiovascular disease, remains to be further elucidate

Anti-hLAMP2-antibodies and dual positivity for anti-GBM and MPO-ANCA in a patient with relapsing pulmonary-renal syndrome

Background Pulmonary-renal syndrome associated with anti-glomerular basement membrane (GBM) antibodies, also known as Goodpasture's syndrome, is a rare but acute and life-threatening condition. One third of patients presenting as anti-GBM antibody positive pulmonary-renal syndrome or rapidly progressive glomerulonephritis are also tested positive for anti-neutrophil cytoplasmic antibodies (ANCA). Whilst anti-GBM disease is considered a non-relapsing condition, the long-term course of double-positive patients is less predictable. Case Presentation We report a patient with such dual positivity, who presented with pulmonary hemorrhage, crescentic glomerulonephritis and membranous nephropathy. Plasmapheresis in combination with immunosuppresive therapy led to a rapid remission but the disease relapsed after two years. The serum of the patient was tested positive for antibodies to human lysosomal membrane protein 2 (hLAMP2), a novel autoantigen in patients with active small-vessel vasculitis (SVV). The anti-hLAMP2 antibody levels correlated positively with clinical disease activity in this patient. Conclusion We hypothesize that this antibody may indicate a clinical course similar to ANCA-associated vasculitis in double-positive patients. However, this needs to be confirmed on comprehensive patient cohorts

Five-year results of lumbar disc prostheses in the SWISSspine registry

Purpose: The Swiss Federal Office of Public Health demanded a nationwide HTA registry for lumbar total disc arthroplasty (TDA), to decide about its reimbursement. The goal of the SWISS spine registry is to generate evidence about the safety and efficiency of lumbar TDA. Methods: Two hundred forty-eight cases treated between 3-2005 and 6-2006, who were eligible for the 5-year follow-up were included in the study. Follow-up rates for 3-6months, 1, 2 and 5years were 85.9, 77.0, 44.0 and 51.2%, respectively. Outcome measures were back and leg pain, medication consumption, quality of life, intraoperative and postoperative complication and revision rates. Additionally, segmental mobility, ossification, adjacent and distant segment degeneration were analysed at the 5-year follow-up. Results: There was a significant, clinically relevant and lasting reduction of back (preop/postop 73/29 VAS points) and leg pain (preop/postop VAS 55/22) and a consequently decreased analgesics consumption and quality of life improvement (preop/postop 0.30/0.76 EQ-5D score points) until 5years after surgery. The rates for intraoperative and early postoperative complications were 4.4 and 3.2%, respectively. The overall complication rate during five postoperative years was 23.4%, and the adjacent segment degeneration rate was 10.7%. In 4.4 % of patients, a revision surgery was performed. Cumulative survivorship probability for a revision/re-intervention-free 5-year postoperative course was 90.4%. At the 5-year follow-up, the average range of motion of the mobile segments (86.8%) was 9.7°. In 43.9% of patients, osteophytes at least potentially affecting the range of motion were seen. Conclusions: Lumbar TDA appeared as efficient in long-term pain alleviation, consequent reduction of pain medication consumption and improvement of quality of life. The procedure also appeared sufficiently safe, but surgeons have to be aware of a list of potential adverse events. The outcome is stable over the 5-year postoperative period. The vast majority of treated segments remained mobile after 5years, although almost half of patients showed osteophytes

Influence of preoperative nucleus pulposus status and radiculopathy on outcomes in mono-segmental lumbar total disc replacement: results from a nationwide registry

Background: Currently, herniated nucleus pulposus (HNP) with radiculopathy and other preconditions are regarded as relative or absolute contraindications for lumbar total disc replacement (TDR). In Switzerland it is left to the surgeon's discretion when to operate. The present study is based on the dataset of SWISSspine, a governmentally mandated health technology assessment registry. We hypothesized that preoperative nucleus pulposus status and presence or absence of radiculopathy has an influence on clinical outcomes in patients treated with mono-segmental lumbar TDR. Methods. Between March 2005 and April 2009, 416 patients underwent mono-segmental lumbar TDR, which was documented in a prospective observational multicenter mode. The data collection consisted of perioperative and follow-up data (physician based) and clinical outcomes (NASS, EQ-5D). Patients were divided into four groups according to their preoperative status: 1) group degenerative disc disease ("DDD"): 160 patients without HNP and no radiculopathy, classic precondition for TDR; 2) group "HNP-No radiculopathy": 68 patients with HNP but without radiculopathy; 3) group "Stenosis": 73 patients without HNP but with radiculopathy, and 4) group "HNP-Radiculopathy": 132 patients with HNP and radiculopathy. The groups were compared regarding preoperative patient characteristics and pre- and postoperative VAS and EQ-5D scores using general linear modeling. Results: Demographics in all four groups were comparable. Regarding the improvement of quality of life (EQ-5D) there were no differences across the four groups. For the two main groups DDD and HNP-Radiculopathy no differences were found in the adjusted postoperative back- and leg pain alleviation levels, in the stenosis group back- and leg pain relief were lower. Conclusions: Despite higher preoperative leg pain levels, outcomes in lumbar TDR patients with HNP and radiculopathy were similar to outcomes in patients with the classic indication; this because patients with higher preoperative leg pain levels benefit from a relatively greater leg pain alleviation. The group with absence of HNP but presence of radiculopathy showed considerably less benefits from the operation, which is probably related to ongoing degenerative processes of the posterior segmental structures. This observational multicenter study suggests that the diagnoses HNP and radiculopathy, combined or alone, may not have to be considered as absolute or relative contraindications for mono-segmental lumbar TDR anymore, whereas patients without HNP but with radiculopathy seem to be suboptimal candidates for the procedure. © 2011 Zweig et al; licensee BioMed Central Ltd

Approximation of Atomic Interactions with Spherical Harmonics

We detail a framework to systematically derive polynomial basis functions for approximating isometry and permutation invariant functions, particularly with an eye to modelling properties of atomistic systems and analyzing the convergence to a high-fidelity reference model. Our presentation builds on (Drautz, Phys. Rev. B 99, 2019), extending the derivation in a way that yields immediate guarantees that a complete basis is indeed obtained. In addition, we discuss generalisations, a variety of related open challenges, particularly from a numerical analysis perspective, around basis optimisation and parameter estimation

Late antibody-mediated rejection by de novo donor HLA-DP-specific antibody after renal transplantation: A case report

The role of donor HLA-DP-specific antibodies after renal transplantation is controversial, and only preformed HLA-DP-specific antibodies have been shown to mediate rejection. Here we present a case of late humoral rejection mediated by de novo donor HLA-DP-specific antibodies in a non-sensitized recipient. This unique case demonstrates the pathogenic role of de novo anti-DP antibodies and suggests that HLA-DP matching might be relevant for renal transplantation