Overview of Skeletal Repair (Fracture Healing and Its Assessment)

The study of postnatal skeletal repair is of immense clinical interest. Optimal repair of skeletal tissue is necessary in all varieties of elective and reparative orthopedic surgical treatments. However, the repair of fractures is unique in this context in that fractures are one of the most common traumas that humans experience and are the end-point manifestation of osteoporosis, the most common chronic disease of aging. In the first part of this introduction the basic biology of fracture healing is presented. The second part discusses the primary methodological approaches that are used to examine repair of skeletal hard tissue and specific considerations for choosing among and implementing these approaches.

External validation of the clinical indications of computed tomography (CT) of the head in patients with low-energy geriatric hip fractures

INTRODUCTION

On evaluation of the clinical indications of computed tomography (CT) scan of head in the patients with low-energy geriatric hip fractures, Maniar et al. identified physical evidence of head injury, new onset confusion, and Glasgow Coma Scale (GCS)<15 as predictive risk factors for acute findings on CT scan. The goal of the present study was to validate these three criteria as predictive risk factors for a larger population in a wider geographical distribution.

PATIENTS AND METHODS

Patients ≥65 years of age with low-energy hip fractures from 6 trauma centers in a wide geographical distribution in the United States were included in this study. In addition to the relevant patient demographic findings, the above mentioned three criteria and acute findings on head CT scan were gathered as categorical variables.

RESULTS

In total 799 patients from 6 centers were included in the study. There were 67 patients (8.3%) with positive acute findings on head CT scan. All of these patients (100%) had at least one criteria positive. There were 732 patients who had negative acute findings on head CT scan with 376 patients (51%) having at least one criteria positive and 356 patients (49%) having no criteria positive. Sensitivity of 100% and negative predictive value of 100% was observed to predict negative acute findings on head CT scan when all the three criteria were negative.

CONCLUSION

With the observed 100% sensitivity and 100% negative predictive value, physical evidence of acute head injury, acute retrograde amnesia, and GCS<15 can be recommended as a clinical decision guide for the selective use of head CT scans in geriatric patients with low energy hip fractures. All the patients with positive acute head CT findings can be predicted in the presence of at least one positive criterion. In addition, if these criteria are used as a pre-requisite to order the head CT, around 50% of the unnecessary head CT scans can be avoided.

Overview of skeletal repair (fracture healing and its assessment)

The study of postnatal skeletal repair is of immense clinical interest. Optimal repair of skeletal tissue is necessary in all varieties of elective and reparative orthopedic surgical treatments. However, the repair of fractures is unique in this context in that fractures are one of the most common traumas that humans experience and are the end-point manifestation of osteoporosis, the most common chronic disease of aging. In the first part of this introduction the basic biology of fracture healing is presented. The second part discusses the primary methodological approaches that are used to examine repair of skeletal hard tissue and specific considerations for choosing among and implementing these approaches.

Generation of closed transverse fractures in small animals

The most common procedure that has been developed for use in rats and mice to model fracture healing is described. The nature of the regenerative processes that may be assessed and the types of research questions that may be addressed with this model are briefly outlined. The detailed surgical protocol to generate closed simple transverse fractures is presented, and general considerations when setting up an experiment using this model are described.

ALOX5AP and LTA4H polymorphisms modify augmentation of bronchodilator responsiveness by leukotriene modifiers in Latinos

BACKGROUND

Understanding the effects of interactions between multiple genes and asthma medications may aid in the understanding of the heterogeneous response to asthma therapies.

OBJECTIVE

To identify modulating effects of arachidonate 5-lipoxygenase-activating protein (ALOX5AP) and leukotriene A(4) hydrolase (LTA4H) gene polymorphisms on the drug-drug interaction between leukotriene modifiers and albuterol in Mexicans and Puerto Ricans.

METHODS

In a cross-sectional study of 293 Mexicans and 356 Puerto Ricans with asthma, ALOX5AP and LTA4H genes were sequenced, and interactions between gene polymorphisms and bronchodilator responsiveness to albuterol were compared between leukotriene modifier users and nonusers.

RESULTS

In heterozygotes and homozygotes for the minor allele at LTA4H single nucleotide polymorphism (SNP) rs2540491 and heterozygotes for the major allele at LTA4H SNP rs2540487, leukotriene modifier use was associated with a clinically significant increase in percent change in FEV(1) after albuterol administration of 7.10% (P = .002), 10.06% (P = .001), and 10.03% (P < .001), respectively. Presence of the major allele at ALOX5AP SNP rs10507391 or the minor allele at ALOX5AP SNP rs9551963 augmented this response. When stratified by ethnicity, these findings held true for Puerto Ricans but not Mexicans.

CONCLUSION

LTA4H and ALOX5AP gene polymorphisms modify the augmentation of bronchodilator responsiveness by leukotriene modifiers in Puerto Ricans but not Mexicans with asthma.