Bilateral femoral neck fractures due to transient osteoporosis of pregnancy: a case report

We describe a case of bilateral femoral neck fractures secondary to transient osteoporosis of pregnancy, which were diagnosed after delivery due to the desire to avoid ionising radiation. These fractures were presumed to be secondary to transient osteoporosis of pregnancy and were treated successfully with internal fixation despite delayed presentation. We discuss the role of MRI in the evaluation of hip pain in pregnancy

Visualizing cell-laden fibrin-based hydrogels using cryogenic scanning electron microscopy and confocal microscopy

The present investigation explores the microscopic aspects of cell-laden hydrogels at high resolutions, using three-dimensional cell cultures in semi-synthetic constructs that are of very high water content (>98% water). The study aims to provide an imaging strategy for these constructs, while minimizing artefacts. Constructs of poly(ethylene glycol)-fibrinogen and fibrin hydrogels containing embedded mesenchymal cells (human dermal fibroblasts) were first imaged by confocal microscopy. Next, high-resolution scanning electron microscopy (HR-SEM) was used to provide images of the cells within the hydrogels, at submicron resolutions. Because it was not possible to obtain artefact-free images of the hydrogels using room-temperature HR-SEM, a cryogenic HR-SEM imaging methodology was employed to visualize the sample while preserving the natural hydrated state of the hydrogel. The ultrastructural details of the constructs were observed at subcellular resolutions, revealing numerous cellular components, the biomaterial in its native configuration, and the uninterrupted cell membrane as it relates with the biomaterial in the hydrated state of the construct. Constructs containing microscopic albumin microbubbles were also imaged using these methodologies to reveal fine details of the interaction between the cells, the microbubbles, and the hydrogel. Taken together with the confocal microscopy, this imaging strategy provides a more complete picture of the hydrated state of the hydrogel network with cells inside. As such, this methodology addresses some of the challenges of obtaining this information in amorphous hydrogel systems containing a very high water content (>98%) with embedded cells. Such insight may lead to better hydrogel-based strategies for tissue engineering and regeneration

Supplementary Material for: Characteristics of Unsuccessful Balance Reactive Responses to Lateral Loss of Balance in Older Adults

Introduction: An effective reactive step response to an unexpected balance loss is an important factor that determines if a fall will happen. We investigated reactive step strategies and kinematics of unsuccessful balance recovery responses that ended with falls in older adults. Methods: We compared the strategies and kinematics of reactive stepping after a lateral loss of balance, i.e., perturbations, between 49 older female adults who were able to successfully recover from perturbations (perturbation-related non-fallers, PNFs) and 10 female older adults who failed to recover (perturbation-related fallers, PFs). In addition, we compared the successful versus unsuccessful recovery responses of PFs matched to perturbation magnitude. Results: The kinematics of the first reactive step response were significantly different between PFs and PNFs, i.e., longer initiation time, step time, swing time, and time to peak swing-leg velocity, larger first-step length, and center of mass displacement. Incomplete crossover stepping and leg collision were significant causes of falls among PFs. Similar findings were found when we compared the successful versus unsuccessful recovery responses of PFs. Conclusions: The crossover step, which requires a complex coordinated leg movement, resulted in difficulty in controlling and decelerating the moving center of mass following a lateral perturbation, affecting the kinematics of the stepping response, leading to a fall