Andrew P. Kurmis

Understanding the limitations of the journal impact factor.

The impact factor, a simple mathematical formula reflecting the number of citations of a journals material divided by the number of citable materials published by that same journal, has evolved to become one of the most influential tools in modern research and academia. The impact factor can be influenced and biased (intentionally or otherwise) by many factors. Extension of the impact factor to the assessment of journal quality or individual authors is inappropriate. Extension of the impact factor to cross-discipline journal comparison is also inappropriate. Those who choose to use the impact factor as a comparative tool should be aware of the nature and premise of its derivation and also of its inherent flaws and practical limitations.

The Effect of Nonsteroidal Anti-Inflammatory Drug Administration on Acute Phase Fracture-Healing: A Review

BACKGROUND The analgesic efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) is well established, and these agents often form an integral part of posttraumatic pain management. However, potentially deleterious effects of resulting prostaglandin suppression on fracture-healing have been suggested. METHODS A systematic literature review involving searches of electronic databases and online sources was performed to identify articles exploring the influence of NSAIDs on fracture-healing. RESULTS A structured search approach identified 316 papers as potentially relevant to the topic, and these were manually reviewed. The majority described small-scale studies that were retrospective or observational in nature, with limited control of potentially confounding variables, or presented little key information that was not also present in other studies. CONCLUSIONS Although increasing evidence from animal studies suggests that cyclooxygenase-2 (COX-2) inhibition suppresses early fracture-healing, in vivo studies involving human subjects have not provided convincing evidence to substantiate this concern. We found no robust evidence to attest to a significant and appreciable patient detriment resulting from the short-term use of NSAIDs following a fracture. The balance of evidence in the available literature appears to suggest that a short-duration NSAID regimen is a safe and effective supplement to other modes of post-fracture pain control, without a significantly increased risk of sequelae related to disrupted healing.

Connexin 26 mutations in autosomal recessive deafness disorders: a review.

This review explores the association between GJB2 gene mutations, encoding connexin 26 (Cx26), and nonsyndromic hearing loss. Connexins are proteins that form intracellular membrane channels and regulate ion movement between contiguous fluid spaces. A family of autosomal gene mutations has been identified that lead to abnormal connexin expression within the inner ear that are associated with hearing loss. The exact mechanism by which this link is elicited remains unclear. We aim to highlight the clinically underestimated prevalence of GJB2 gene mutations, to explore the influential role of ethnic diversity in mutation frequency, and to provide a framework for hearing specialists in considering the differential diagnosis of nonsyndromic hearing loss. By linking an observed phenotype associated with abnormal Cx26 expression to the current understanding of the biological and genetic basis underlying it will allow a more accurate clinical description of associated hearing loss, and therefore enable more effective patient management and genetic counselling.

The accuracy of three-dimensional reconstructions of the ovine knee: dissectional validation.

A single, complete, ovine knee was imaged using conventional MRI then dissected allowing comprehensive dimensional measurement of the intra-articular structures. A three-dimensional (3-D) computer model of the knee was generated from the MR sections. Thirty-two individual structural measures were recorded from the image output for which there was an available surgical measure for direct comparison. The results of Pearsons correlation testing show a rounded score of 1.00, suggesting an exceptional linear correlation between direct anatomical measurement and the 3-D image output. Further analysis of the data revealed an average error of measurement of 0.2mm across the 32 measures. The findings of this preliminary study suggest that 3-D reconstruction from MR data may be an appropriate, and accurate, means for making dimensional measurements of the bony and soft tissue structures of the ovine knee. It is unlikely that the measurement error would be of any great clinical significance. There is evidence in the literature to suggest that an ovine knee may be considered an acceptable model for substitution for the human knee in diagnostic assessment studies. Therefore, such findings may be considered clinically relevant in the field of human knee assessment.

The utilization of a synthetic bone void filler (JAX) in the repair of a femoral segmental defect

OBJECTIVES Currently available synthetic void fillers are indicated for bony voids or gaps that are not intrinsic to the stability of the structure. Jax TCP (tricalcium phosphate) is an osteoconductive bioceramic fabricated into 4 mm granules with a unique interlocking form, promoting structural integrity while allowing bone ingrowth. The objective of this study was to assess bone ingrowth using a large, critically sized, femoral defect. METHODS A 5 cm segmental ostectomy was created in the mid-diaphysis of 16 adult ovine femora. A stainless steel intramedullary nail was introduced and locked with two proximal and two distal fully-threaded locking screws. Each defect was surrounded with a resorbable macroporous poly (L-lactide-co-D,L) lactide mesh acting as graft containment. Treatment groups (n = 4) were as follows: 1) Empty defect; 2) Morselized cortical bone; 3) Cortical strut; 4) Jax TCP. Serial radiographs were taken postoperatively and at two, four and six months. Femora retrieved at necropsy (six months) underwent computed tomography for volumetric analysis followed by histological assessment of the biological response. RESULTS Little bone was apparent in the empty defect group, whereas significant bone was evident in both autograft groups and the Jax TCP group. Three-dimensional CT reconstructions and volumetric analysis were in close agreement with the radiographic findings. CLINICAL SIGNIFICANCE Jax TCP bone graft substitute has been proven to be effective in the healing of a large, critically sized, contained segmental defect. The healing observed was superior to that of cortical struts and the new bone laid down had similar radio-opacity to autograft.

Review article: Thromboprophylaxis after total hip replacement

The risk of secondary haematologic complications such as deep vein thrombosis or pulmonary embolism increases significantly when a transient period of hypercoagulability is induced after total hip replacement (THR). A number of drug-based anticoagulant approaches are available to modulate this risk, but the optimal length of therapy for such approaches remains unclear. The literature was reviewed for evidence-based support of the routine use of an extended course (>14 days) of thromboprophylaxis after THR. Electronic databases and real-time online literature searches were performed, using the PubMed (Medline), EMBASE, CINAHL and GoogleScholar, and the Cochrane and British Medical Journal Clinical Evidence libraries. Author-defined key word searches were performed. Only articles in the English language, for which full text could be retrieved, were reviewed. There is robust evidence to support an extended course (>14 days) of thromboprophylaxis after THR. Such recommendations have been translated into the guidelines of key professional bodies, including those of the American College of Chest Physicians. Meta-review suggests a clear benefit of such regimens and supports wider adoption, even when weighed against a small increase in adverse events.

The effect of base image window level selection on the dimensional measurement accuracy of resultant three-dimensional image displays

Abstract Purpose: The aim of this study was to determine the effect of base image window level selection on direct linear measurement of knee structures displayed using new magnetic resonance (MR)-based three-dimensional reconstructed computer imaging techniques. Methods: A prospective comparative study was performed using a series of three-dimensional knee images, generated from conventional MR imaging (MRI) sections. Thirty distinct anatomical structural features were identified within the image series of which repeated measurements were compared at 10 different window grey scale levels. Results: Statistical analysis demonstrated an excellent raw correlation between measurements and suggested no significant difference between measurements made at each of the 10 window level settings ( P >0.05). Conclusions: The findings of this study suggest that unlike conventional MR or CT applications, grey scale window level selection at the time of imaging does not significantly affect the visual quality of resultant three-dimensional reconstructed images and hence the accuracy of subsequent direct linear measurement. The diagnostic potential of clinical progression from routine two-dimensional to advanced three-dimensional reconstructed imaging techniques may therefore be less likely to be degraded by inappropriate MR technician image windowing during the capturing of image series.