Differing risk profiles for individual fracture sites: Evidence from the global longitudinal study of osteoporosis in women (GLOW)

The purposes of this study were to examine fracture risk profiles at specific bone sites, and to understand why model discrimination using clinical risk factors is generally better in hip fracture models than in models that combine hip with other bones. Using 3-year data from the GLOW study (54,229 women with more than 4400 total fractures), we present Cox regression model results for 10 individual fracture sites, for both any and first-time fracture, among women aged ≥55 years. Advanced age is the strongest risk factor in hip (hazard ratio [HR] = 2.3 per 10-year increase), pelvis (HR = 1.8), upper leg (HR = 1.8), and clavicle (HR = 1.7) models. Age has a weaker association with wrist (HR = 1.1), rib (HR = 1.2), lower leg (not statistically significant), and ankle (HR = 0.81) fractures. Greater weight is associated with reduced risk for hip, pelvis, spine, and wrist, but higher risk for first lower leg and ankle fractures. Prior fracture of the same bone, although significant in nine of 10 models, is most strongly associated with spine (HR = 6.6) and rib (HR = 4.8) fractures. Past falls are important in all but spine models. Model c indices are ≥0.71 for hip, pelvis, upper leg, spine, clavicle, and rib, but ≤0.66 for upper arm/shoulder, lower leg, wrist, and ankle fractures. The c index for combining hip, spine, upper arm, and wrist (major fracture) is 0.67. First-time fracture models have c indices ranging from 0.59 for wrist to 0.78 for hip and pelvis. The c index for first-time major fracture is 0.63. In conclusion, substantial differences in risk profiles exist among the 10 bones considered. © 2012 American Society for Bone and Mineral Research.     

To stand back or step in? Exploring the responses of employees who observe workplace bullying

Bullying remains a pervasive problem in healthcare, and evidence suggests systems in place are not utilised due to perceptions of ineffectiveness and inequity. This study examines bystander responses to bullying and factors that influence decisions to intervene. We explore relationships between bystanders’ perceptions of psychological safety across three levels (organisation, supervisor and colleague) and reactions to witnessing bullying. We suggest psychological safety would be positively associated with the decision to intervene. Findings indicate the most pervasive reaction to witnessing incidents of bullying is to discuss with colleagues, a low‐involvement reaction. We find perceptions of supervisory and organisational safety/support are positively related to high‐involvement decisions such as formal reporting of the incidents, highlighting the importance of support from those in power. However, perceptions of collegial support may lead to low‐involvement responses, which risk reinforcing and underpinning dysfunctional organisational dynamics by providing informal social and emotional responses that may substitute more formal organisational responses to this persistent problem. This study highlights the importance of support from individuals in power if bystanders are to feel comfortable making high‐involvement interventions.     

Caring for children,focusing on children

Two First Nations girls with leukemia received a significant amount of media attention in 2014 and 2015. In both cases, the parents refused to continue chemotherapy, the only proven effective treatment; they opted instead for a combination of traditional Aboriginal healing approaches and alternative therapies offered in a facility outside of the country. One child has died; the other relapsed and required chemotherapy to avoid death.Media reports were polarized, focusing either on the historical legacy of distrust felt by First Nations people when accessing health care, or the need for child protection services to intervene. One article in the Canadian Medical Association Journal focused on the legacy of mistrust and methods of countering it, but did not address the legal and ethical duties of physicians in such situations.The present commentary describes the events, responsibilities of professionals involved and a course of action for physicians when faced with similar circumstances.     

A fatal case of primary cutaneous gamma–delta T‐cell lymphoma complicated by HLH and cardiac amyloidosis

Gamma–delta T‐cell lymphomas (GD‐TCL) are rare and rapidly fatal neoplasms that are often associated with Hemophagocytic Lymphohistiocytosis (HLH), a syndrome of fevers, cytopenias, and multiorgan failure that often leads to a rapid death. We report the first case demonstrating an association between GD‐TCL, HLH, and cardiac amyloidosis, presenting a novel mechanism for rapid deterioration in these patients.     

18F-fluoride Positron Emission Tomography Measurements of Regional Bone Formation in Hemodialysis Patients with Suspected Adynamic Bone Disease

¹⁸F-fluoride positron emission tomography (¹⁸F-PET) allows the assessment of regional bone formation and could have a role in the diagnosis of adynamic bone disease (ABD) in patients with chronic kidney disease (CKD). The purpose of this study was to examine bone formation at multiple sites of the skeleton in hemodialysis patients (CKD5D) and assess the correlation with bone biopsy. Seven CKD5D patients with suspected ABD and 12 osteoporotic postmenopausal women underwent an ¹⁸F-PET scan, and bone plasma clearance, K _i, was measured at ten skeletal regions of interest (ROI). Fifteen subjects had a transiliac bone biopsy following double tetracycline labeling. Two CKD5D patients had ABD confirmed by biopsy. There was significant heterogeneity in K _i between skeletal sites, ranging from 0.008 at the forearm to 0.028 mL/min/mL at the spine in the CKD5D group. There were no significant differences in K _i between the two study groups or between the two subjects with ABD and the other CKD5D subjects at any skeletal ROI. Five biopsies from the CKD5D patients had single tetracycline labels only, including the two with ABD. Using an imputed value of 0.3 μm/day for mineral apposition rate (MAR) for biopsies with single labels, no significant correlations were observed between lumbar spine K _i corrected for BMAD (K _i/BMAD) and bone formation rate (BFR/BS), or MAR. When biopsies with single labels were excluded, a significant correlation was observed between K _i/BMAD and MAR (r = 0.81, p = 0.008) but not BFR/BS. Further studies are required to establish the sensitivity of ¹⁸F-PET as a diagnostic tool for identifying CKD patients with ABD.     

Measuring aortic valve coaptation surface area using three-dimensional transesophageal echocardiography

Background

As aortic valve (AV) repairs become more sophisticated, surgeons need increasingly detailed information about the structure and function of this valve. Unlike two-dimensional transesophageal echocardiography (2D-TEE), using three-dimensional (3D)-TEE makes it possible to image the entire AV. We hypothesized that measuring coaptation surface area (CoapSA) would be feasible and reproducible, and CoapSA would decrease in patients with aortic insufficiency.

Methods

We developed a new technique to calculate the AV-CoapSA using 3D-TEE. We measured the coaptation surfaces between the right coronary cusp/left coronary cusp, right coronary cusp/non-coronary cusp, and left coronary cusp/non-coronary cusp in ten normal AVs and ten AVs with moderate-severe aortic insufficiency (AI). Since computer models have previously shown that CoapSA is trapezoidal, we used the formula: trapezoid area = length × (medial coaptation height + lateral coaptation height)/2. The total CoapSA was calculated by adding all three areas. To adjust for valve size, we indexed the value to the diameter of the ventricular aortic junction (VAJ). Measurements were performed by two observers.

Results

The intra-observer correlation was 0.84 for one observer (P < 0.0001) and 0.93 for the other (P < 0.0001). The inter-observer correlation was 0.87 (P < 0.0001). In normal valves, the CoapSA [mean total (standard deviation)] was significantly greater than in the insufficient valves [1.61 (0.31) cm² vs 1.03 (0.22) cm², respectively; P < 0.001]. After indexing for the VAJ diameter, the total CoapSA remained significantly greater in normal valves than in insufficient valves.

Conclusion

In this proof of concept study, we present a new and innovative technique to measure AV-CoapSA using 3D-TEE. It is reproducible and shows decreased CoapSA in patients with AI. Coaptation surface area may provide insight into mechanisms of AI and may have predictive value following AV repair.