Atlantoaxial osteoarthritis: case series and review of the literature

The intention of this study is to present our experience in the surgical treatment of painful atlantoaxial osteoarthritis (AAOA) and review the literature on this subject. Osteoarthritis of the atlantoaxial joints is more common than is generally suspected. It has a prevalence between 5 and 18%. Only a minority of patients becomes symptomatic suffering from severe suboccipital pain, irradiating into the occiput, vertex and sometimes as far as the eyes. Most often, these patients can successfully be treated conservatively. Some of these patients however require operative treatment. The study includes five patients with painful AAOA (one posttraumatic, four idiopathic) not responding to conservative treatment for a minimum of sixmonths. Rheumatoid arthritis was excluded. All but one patient were female and all but one patient were over 50years old (mean 64years). The origin of pain was confirmed by diagnostic C1-C2 facet blocks in all patients. The patients were treated with a C1-C2 transarticular screw fixation and Gallie type fusion. Patients were followed clinically and radiologically for a minimum of 24months. Mean follow-up was 38months (24-48). In all patients the typical pain disappeared immediately after surgery and has not reoccurred. Pain intensity on the VAS decreased from 100 to 34. At the latest follow-up radiologically solid fusion and stable implants were found in all cases. All five patients would undergo this surgery for the same condition again. C1-C2 fusion effectively relieves occipitocervical pain in AAOA non responsive to conservative treatmen

Spontaneous In Vivo Chondrogenesis of Bone Marrow-Derived Mesenchymal Progenitor Cells by Blocking Vascular Endothelial Growth Factor Signaling

Chondrogenic differentiation of bone marrow-derived mesenchymal stromal/stem cells (MSCs) can be induced by presenting morphogenetic factors or soluble signals but typically suffers from limited efficiency, reproducibility across primary batches, and maintenance of phenotypic stability. Considering the avascular and hypoxic milieu of articular cartilage, we hypothesized that sole inhibition of angiogenesis can provide physiological cues to direct in vivo differentiation of uncommitted MSCs to stable cartilage formation. Human MSCs were retrovirally transduced to express a decoy soluble vascular endothelial growth factor (VEGF) receptor-2 (sFlk1), which efficiently sequesters endogenous VEGF in vivo, seeded on collagen sponges and immediately implanted ectopically in nude mice. Although naïve cells formed vascularized fibrous tissue, sFlk1-MSCs abolished vascular ingrowth into engineered constructs, which efficiently and reproducibly developed into hyaline cartilage. The generated cartilage was phenotypically stable and showed no sign of hypertrophic evolution up to 12 weeks. In vitro analyses indicated that spontaneous chondrogenic differentiation by blockade of angiogenesis was related to the generation of a hypoxic environment, in turn activating the transforming growth factor-β pathway. These findings suggest that VEGF blockade is a robust strategy to enhance cartilage repair by endogenous or grafted mesenchymal progenitors. This article outlines the general paradigm of controlling the fate of implanted stem/progenitor cells by engineering their ability to establish specific microenvironmental conditions rather than directly providing individual morphogenic cues.; Chondrogenic differentiation of mesenchymal stromal/stem cells (MSCs) is typically targeted by morphogen delivery, which is often associated with limited efficiency, stability, and robustness. This article proposes a strategy to engineer MSCs with the capacity to establish specific microenvironmental conditions, supporting their own targeted differentiation program. Sole blockade of angiogenesis mediated by transduction for sFlk-1, without delivery of additional morphogens, is sufficient for inducing MSC chondrogenic differentiation. The findings represent a relevant step forward in the field because the method allowed reducing interdonor variability in MSC differentiation efficiency and, importantly, onset of a stable, nonhypertrophic chondrocyte phenotype

Assessment of nerve damage using a novel ultrasonic device for bone cutting

El plan de negocios y/o proyecto de factibilidad representa la mejor alternativa de inversión con un nivel de rentabilidad mayor al costo de oportunidad del capital. Para que el retorno del proyecto sea mayor al costo de oportunidad, esto significa sustentar los flujos de beneficios que ofrece el proyecto, con la determinación de la demanda insatisfecha y un desempeño eficiente del negocio; consecuentemente, determinar la demanda insatisfecha es un elemento clave para demostrar la factibilidad del proyecto. No siempre se dispone de estadísticas para el estudio de mercado de nuevas oportunidades de negocios; en tal sentido, se ha preparado esta metodología, con base en un estudio de caso para la determinación del mercado objetivo y demanda insatisfecha cuando no se dispone de estadísticas.The business plan and / or feasibility study represents the best investment alternative, with a level of return greater than the opportunity cost of capital. When the return of the project is greater than the opportunity cost, means sustaining the flow of benefits of the project, with the determination of unmet demand and an efficient performance of the project, and consequently, determine the unmet demand is a key element to show the feasibility of the project. There is not always available statistics for the market research of new business opportunities, in this sense, we have developed this methodology, based on a case study for the determination of the target market and unmet when there are no statistics

Cardiovascular imaging following perioperative myocardial infarction/injury

Patients developing perioperative myocardial infarction/injury (PMI) have a high mortality. PMI work-up and therapy remain poorly defined. This prospective multicenter study included high-risk patients undergoing major non-cardiac surgery within a systematic PMI screening and clinical response program. The frequency of cardiovascular imaging during PMI work-up and its yield for possible type 1 myocardial infarction (T1MI) was assessed. Automated PMI detection triggered evaluation by the treating physician/cardiologist, who determined selection/timing of cardiovascular imaging. T1M1 was considered with the presence of a new wall motion abnormality within 30 days in transthoracic echocardiography (TTE), a new scar or ischemia within 90 days in myocardial perfusion imaging (MPI), and Ambrose-Type II or complex lesions within 7 days of PMI in coronary angiography (CA). In patients with PMI, 21% (268/1269) underwent at least one cardiac imaging modality. TTE was used in 13% (163/1269), MPI in 3% (37/1269), and CA in 5% (68/1269). Cardiology consultation was associated with higher use of cardiovascular imaging (27% versus 13%). Signs indicative of T1MI were found in 8% of TTE, 46% of MPI, and 63% of CA. Most patients with PMI did not undergo any cardiovascular imaging within their PMI work-up. If performed, MPI and CA showed high yield for signs indicative of T1MI.Trial registration: https://clinicaltrials.gov/ct2/show/NCT02573532

Myelin Proteomics: Molecular Anatomy of an Insulating Sheath

Fast-transmitting vertebrate axons are electrically insulated with multiple layers of nonconductive plasma membrane of glial cell origin, termed myelin. The myelin membrane is dominated by lipids, and its protein composition has historically been viewed to be of very low complexity. In this review, we discuss an updated reference compendium of 342 proteins associated with central nervous system myelin that represents a valuable resource for analyzing myelin biogenesis and white matter homeostasis. Cataloging the myelin proteome has been made possible by technical advances in the separation and mass spectrometric detection of proteins, also referred to as proteomics. This led to the identification of a large number of novel myelin-associated proteins, many of which represent low abundant components involved in catalytic activities, the cytoskeleton, vesicular trafficking, or cell adhesion. By mass spectrometry-based quantification, proteolipid protein and myelin basic protein constitute 17% and 8% of total myelin protein, respectively, suggesting that their abundance was previously overestimated. As the biochemical profile of myelin-associated proteins is highly reproducible, differential proteome analyses can be applied to material isolated from patients or animal models of myelin-related diseases such as multiple sclerosis and leukodystrophies

Union Rate and Complications in Spine Fusion with Recombinant Human Bone Morphogenetic Protein-7: Systematic Review and Meta-Analysis

Study Design Systematic review and meta-analysis. Objective: The objective of this meta-analysis was to evaluate the current best evidence to assess effectiveness and safety of recombinant human bone morphogenetic protein-7 (rhBMP-7) as a biological stimulant in spine fusion. Methods: Studies were included if they reported on outcomes after spine fusion with rhBMP-7. The data was synthesized using Mantel-Haenszel pooled risk ratios (RRs) with 95% confidence intervals (CIs). Main end points were union rate, overall complications, postoperative back and leg pain, revision rates, and new-onset cancer. Results: Our search produced 796 studies, 6 of which were eligible for inclusion. These studies report on a total of 442 patients (328 experimental, 114 controls) with a mean age of 59 ± 11 years. Our analysis showed no statistically significant differences in union rates (RR 0.97, 95% CI 0.84 to 1.11, p = 0.247), overall complications (RR 0.92, 95% CI 0.71 to 1.20, p = 0.545), postoperative back and leg pain (RR 1.03, 95% CI 0.48 to 2.19, p = 0.941), or revision rate (RR 0.81, 95% CI 0.47 to 1.40, p = 0.449). There was a mathematical indicator of increased tumor rates, but with only one case, the clinical meaningfulness of this finding is questionable. Conclusion: We were not able to find data in support of the use of rhBMP-7 for spine fusion. We found no evidence for increased complication or revision rates with rhBMP-7. On the other hand, we also found no evidence in support of improved union rates

Management of Incidental Dural Tear During Lumbar Spine Surgery. To Suture or Not to Suture?

OBJECTIVE: Incidental durotomy (ID) during lumbar spine surgery is a frequent complication of growing clinical relevance as the number and complexity of spinal procedures increases. Yet, there is still a lack of guidelines for the treatment of ID with a large heterogeneity of established surgical techniques. The aim of this study was to investigate the efficacy of dural suturing in patients having ID during degenerative lumbar spine surgery, compared with other dural closure techniques. METHODS: Of 1173 consecutive patients undergoing degenerative lumbar spine surgery from July 2013 to March 2015, in 64 (5.4%) patients 69 (5.8%) IDs occurred. The patients were divided into 3 groups depending on the dural closure technique used: group A, sole dural suture (n = 12, 19%); group B, patch only (TachoSil and/or muscle and/or fat) (n = 22, 32%); group C, dural suture in combination with a patch (n = 34, 49%). The primary end point was revision surgery caused by complications of cerebrospinal fluid leakage after 6 weeks. The secondary end points were operation time and hospitalization time, as well as surgical morbidity. RESULTS: The 3 groups showed no significant difference in rates of revision surgery (group A: n = 1, 1.4%; group B: n = 4, 5.8%; group C: n = 3; 4.3%; P = 0.5). Furthermore, no significant difference for hospitalization time, operation time, and clinical outcome was found. Extent of ID, American Society of Anesthesiology score, postoperative immobilization, and insertion of a drainage tube were not associated with higher rates of revision surgery. Applying suction once a drainage tube was placed was found to be a significant risk factor for revision surgery (P = 0.003). Furthermore, patients undergoing revision surgery had a significantly higher body mass index (33 kg/m(2) vs. 26.37 kg/m(2); P = 0.006; odds ratio 1.252; P = 0.004). CONCLUSIONS: Based on our results, the dural closure technique after ID does not seem to influence revision surgery rates due to cerebrospinal fluid leakage and its complications. Further prospective randomized studies are needed to confirm our results

Dynamic Stabilization in Addition to Decompression for Lumbar Spinal Stenosis with Degenerative Spondylolisthesis

Study Design. Prospective clinical study. Objective. To test whether elastic stabilization with the Dynesys system (Zimmer Spine, Minneapolis, MN) provides enough stability to prevent further progression of spondylolisthesis as well as instability after decompression for spinal stenosis with degenerative spondylolisthesis. Summary of Background Data. In spinal stenosis with degenerative spondylolisthesis, decompression and fusion is widely recommended. However, patients have donor site pain. In 1994, a dynamic transpedicular system (Dynesys) was introduced to the market, stating that stabilization is possible without bone grafting. Methods. A total of 26 patients (mean age 71 years) with lumbar spinal stenosis and degenerative spondylolisthesis underwent interlaminar decompression and dynamic stabilization with the Dynesys system. Minimum follow-up was 2 years. Operative data, clinical outcome, and plain and flexion/extension radiographs were obtained and compared to preoperative and postoperative data. Results. Mean leg pain decreased significantly (P Ͻ 0.01), and mean walking distance improved significantly to more than 1000 m (P Ͻ 0.01). There were 5 patients (21%) who still had some claudication. A total of 21 patients (87.5%) would undergo the same procedure again. Radiographically, no significant progression of spondylolisthesis could be detected. The implant failure rate was 17%, and none of them were clinically symptomatic. Conclusions. In elderly patients with spinal stenosis with degenerative spondylolisthesis, dynamic stabilization with the Dynesys system in addition to decompression leads to similar clinical results as seen in established protocols using decompression and fusion with pedicle screws. It maintains enough stability to prevent further progression of spondylolisthesis or instability. With the Dynesys system, no bone grafting is necessary, therefore, donor site morbidity can be avoided