Perioperative management of external fixation in staged protocols: an international survey

Introduction

Despite the frequent use of external fixation, various regimes of antibiotic prophylaxis, surgical technique and postoperative pin care exist and underline the lack of current evidence. The aim of the study was to assess the variability or consensus in perioperative protocols to prevent implant-associated infections for temporary external fixation in closed fractures of the extremities.

Materials and methods

A 26-question survey was sent to 170 members of the Traumaplatform. The survey included questions concerning demographics, level of training, type of training and perioperative protocols as: antibiotic prophylaxis, intraoperative management, disinfection and postoperative pin site care. All responses were statistically analysed, and intraoperative measures rated on a 5-point Likert scale.

Results

The responses of fifty orthopaedic trauma and general surgeons (response rate, 29.4%) were analysed. The level of experience was more than 5 years in 92% (n = 46) with up to 50 closed fractures of the extremities annually treated with external fixation in 80% (n = 40). Highest consensus could be identified in the following perioperative measures: preoperative antibiotic prophylaxis with a second-generation cephalosporin (86%, n = 43), changing gloves if manipulation of the external fixator is necessary during surgery (86%, n = 43; 4.12 points on the Likert scale), avoid overlapping of the pin sites with the definitive implant site (94%, n = 47; 4.12 points on the Likert scale) and soft tissue protection with a drill sleeve (83.6%, n = 41).

Conclusion

Our survey could identify some general principles, which were rated as important by a majority of the respondents. Futures studies’ focus should elucidate the role of perioperative antibiotics and different disinfection protocols on implant-associated infections after temporary external fixation in staged protocols.

Level of evidence

This study provides Level IV evidence according to Oxford centre for evidence-based medicine.

     

Severity of foraminal lumbar stenosis and the relation to clinical symptoms and response to periradicular infiltration—introduction of the “melting sign”

Background Context

Nerve root compression causing symptomatic radiculopathy can occur within the intervertebral foramen. Sagittal magnetic resonance imaging (MRI) sequences are reliable in detection of nerve root contact to intraforaminal disc material, but a clinically relevant classification of degree of contact is lacking.

Accuracy of automatic tube compensation in new-generation mechanical ventilators

OBJECTIVE: To compare performance of flow-adapted compensation of endotracheal tube resistance (automatic tube compensation, ATC) between the original ATC system and ATC systems incorporated in commercially available ventilators. DESIGN: Bench study. SETTING: University research laboratory. SUBJECTS: The original ATC system, Dr?ger Evita 2 prototype, Dr?ger Evita 4, Puritan-Bennett 840. INTERVENTIONS: The four ventilators under investigation were alternatively connected via different sized endotracheal tubes and an artificial trachea to an active lung model. Test conditions consisted of two ventilatory modes (ATC vs. continuous positive airway pressure), three different sized endotracheal tubes (inner diameter 7.0, 8.0, and 9.0 mm), two ventilatory rates (15/min and 30/min), and four levels of positive end-expiratory pressure (0, 5, 10, and 15 cm H2O). MEASUREMENTS AND MAIN RESULTS: Performance of tube compensation was assessed by the amount of tube-related (additional) work of breathing (WOBadd), which was calculated on the basis of pressure gradient across the endotracheal tube. Compared with continuous positive airway pressure, ATC reduced inspiratory WOBadd by 58%, 68%, 50%, and 97% when using the Evita 4, the Evita 2 prototype, the Puritan-Bennett 840, and the original ATC system, respectively. Depending on endotracheal tube diameter and ventilatory pattern, inspiratory WOBadd was 0.12-5.2 J/L with the original ATC system, 1.5-28.9 J/L with the Puritan-Bennett 840, 10.4-21.0 J/L with the Evita 2 prototype, and 10.1-36.1 J/L with the Evita 4 (difference between each ventilator at identical test situations, p <.025). Expiratory WOBadd was reduced by 5%, 26%, 1%, and 70% with the Evita 4, the Evita 2 prototype, the Puritan-Bennett 840, and the original ATC system, respectively. The expiratory WOBadd caused by an endotracheal tube of 7.0 mm inner diameter was 5.5-42.2 J/L at a low ventilatory rate and 19.6-82.3 J/L at a high ventilatory rate. It was lowest with the original ATC system and highest with the Evita 4 ventilator (p <.025). CONCLUSIONS: Flow-adapted tube compensation by the original ATC system significantly reduced tube-related inspiratory and expiratory work of breathing. The commercially available ATC modes investigated here may be adequate for inspiratory but probably not for expiratory tube compensation.     

Elastic stabilisation of proximal humeral fractures with a new percutaneous angular stable fixation device (ButtonFix®): a preliminary report

Introduction

The ButtonFix^® system represents a new angular stable percutaneous fixation device for stabilisation of fractures of the proximal humerus. The purpose of this study was to present a preliminary report of the radiological and clinical outcome after minimally invasive stabilisation of selected proximal humerus fractures with the ButtonFix^®.

Patients and methods

Seventeen patients with fractures of the proximal humerus were treated in our department with the ButtonFix^® system. The mean final follow-up was performed 19 months postoperatively. Follow-up included assessment of postoperative reposition, range of motion, the DASH score, the Constant–Murley score, and the Short Form 36 (SF36).

Results

Twelve patients showed anatomical head-to-shaft angles, four revealed minor valgus replacement, and one minor varus replacement. In one patient unplanned revision surgery was necessary due to early secondary fracture dislocation requiring ORIF with an angular stable form plate. Implant removal was performed after 6 weeks in all patients. At the final follow-up, mean range of motion was: flexion 135°, extension 45°, abduction 142°, internal rotation 51°, and external rotation 62°. The mean Constant–Murley score was 70. The mean DASH score was 26 points and the average SF36 score was 76 points. One patient showed radiological signs of avascular necrosis.

Conclusion

The ButtonFix^® system represents a valuable tool in the treatment of proximal humeral fractures with results indicating fewer complications compared to prior percutaneous fixation devices. Moreover, the ButtonFix^® seems to be able to maintain reduction even in elderly patients with potentially reduced bone mass.     

Interleukins, from 1 to 37, and interferon-γ: receptors, functions, and roles in diseases

Advancing our understanding of mechanisms of immune regulation in allergy, asthma, autoimmune diseases, tumor development, organ transplantation, and chronic infections could lead to effective and targeted therapies. Subsets of immune and inflammatory cells interact via ILs and IFNs; reciprocal regulation and counter balance among T(h) and regulatory T cells, as well as subsets of B cells, offer opportunities for immune interventions. Here, we review current knowledge about ILs 1 to 37 and IFN-γ. Our understanding of the effects of ILs has greatly increased since the discoveries of monocyte IL (called IL-1) and lymphocyte IL (called IL-2); more than 40 cytokines are now designated as ILs. Studies of transgenic or knockout mice with altered expression of these cytokines or their receptors and analyses of mutations and polymorphisms in human genes that encode these products have provided important information about IL and IFN functions. We discuss their signaling pathways, cellular sources, targets, roles in immune regulation and cellular networks, roles in allergy and asthma, and roles in defense against infections.     

A model for the involvement of neural cell adhesion molecules in stress-related mood disorders

Critical interactions between genetic and environmental factors -- among which stress is one of the most potent non-genomic factors -- are involved in the development of mood disorders. Intensive work during the past decade has led to the proposal of the network hypothesis of depression [Castren E: Nat Rev Neurosci 2005;6:241-246]. In contrast to the earlier chemical hypothesis of depression that emphasized neurochemical imbalance as the cause of depression, the network hypothesis proposes that problems in information processing within relevant neural networks might underlie mood disorders. Clinical and preclinical evidence supporting this hypothesis are mainly based on observations from depressed patients and animal stress models indicating atrophy (with basic research pointing at structural remodeling and decreased neurogenesis as underlying mechanisms) and malfunctioning of the hippocampus and prefrontal cortex, as well as the ability of antidepressant treatments to have the opposite effects. A great research effort is devoted to identify the molecular mechanisms that are responsible for the network effects of depression and antidepressant actions, with a great deal of evidence pointing at a key role of neurotrophins (notably the brain-derived neurotrophic factor) and other growth factors. In this review, we present evidence that implicates alterations in the levels of the neural cell adhesion molecules of the immunoglobulin superfamily, NCAM and L1, among the mechanisms contributing to stress-related mood disorders and, potentially, in antidepressant action.