Histological evidence concerning the osseointegration of titanium implants in the fractured rabbit femur

Stabilization of the broken bone is achieved using biocompatible materials. Since histology is still considered the gold standard technique for the assessment of bone formation around metallic implants, this report investigated the titanium implant integration in the accidentally broken bone in rabbits. The experimental protocol was reviewed and approved by the Ethical Committee of the Faculty of Medicine and Pharmacy Oradea, Romania. Holes were drilled in the diaphysis of the femur, and titanium implants were inserted in the created bone defect. In two subjects, fractures occurred on days two and three after the metallic alloy implantation. The other two rabbits presented no fractures following the surgical procedure. The rabbits were euthanized and the bones (with metallic implants) were harvested for histopathological investigation. Following decalcification, the bone samples were processed using the standard paraffin technique and stained by Goldner’s trichrome procedure. In subjects with a perfect immobilization of the titanium implants, the osseointegration occurred with minimal callus formation (i.e. primary cortical healing). In rabbits with bone fractures, the callus was more exuberant. A progressive replacement of the granulation tissue with hyaline cartilage and woven bone occurred soon after. The former aspects suggested an indirect metaplasia in the created callus. In all subjects, no inflammatory cells were identified in the created callus. The bone regeneration occurred either by primary cortical healing (in perfectly immobilized titanium implants) or by a process similar to the endochondral ossification (in poorly immobilized titanium implants following accidental post-implantation bones fracture).     

Gait kinetics impact shoe tread wear rate

BackgroundAdequate footwear is an important factor for reducing the risk of slipping; as shoe outsoles wear down, friction decreases, and slip and fall risk increases. Wear theory suggests that gait kinetics may influence rate of tread wear.Research questionDo the kinetics of walking (i.e., the shoe-floor force interactions) affect wear rate?MethodsFourteen participants completed dry walking trials during which ground reaction forces were recorded across different types of shoes. The peak normal force, shear force, and required coefficient of friction (RCOF) were calculated. Participants then wore alternating pairs of shoes in the workplace each month for up to 24 months. A pedometer was used to track the distance each pair of shoes was worn and tread loss was measured. The wear rate was calculated as the volumetric tread loss divided by the distance walked in the shoes. Three, mixed linear regression models were used to assess the impact of peak normal force, shear force, and RCOF on wear rate.ResultsWear rate was positively associated with peak RCOF and with peak shear force, but was not significantly related to peak normal forces.SignificanceThe finding that shear forces and particularly the peak RCOF are related to wear suggests that a person’s gait characteristics can influence wear. Therefore, individual gait kinetics may be used to predict wear rate based on the fatigue failure shoe wear mechanism.     

Danger at every rung: Epidemiology and outcomes of ICU-admitted ladder-related trauma

IntroductionThe incidence of ladder-related falls is increasing, and this represents a disturbing trend, particularly in the context of increased life expectancy and the impending retirement of the populous ‘baby-boomer’ generation. To date, there have been no critical illness-focused studies reporting on the incidence, severity and outcomes of severe ladder-related injuries requiring ICU management.MethodsMajor trauma patients admitted to ICU over a 5 year period to June 2011 after ladder falls >1 m were identified from prospectively collected trauma data at a Level 1 trauma service. Demographic and ICU clinical management data were collected and non-parametric statistical analyses were used to explore the relationships between variables in hospital mortality/survival.ResultsThere were 584 ladder fall admissions, including 194 major trauma cases, of whom 29.9% (n = 58) fell >1 m and were admitted to ICU. Hospital mortality was 26%, and fatal cases were almost entirely older males in domestic falls of ≤3 m who died as a result of traumatic brain injury. Non-survivors had lower GCS at the scene (p = 0.02), higher AIS head code (p = 0.01), higher heart rate and lower mean arterial pressure (p < 0.01) in the initial 24 h period in ICU, and were ≥55 years of age (p = 0.05). Only 46% of patients available for follow-up were living at home at 12 months without requiring additional care.ConclusionsThe incidence of ladder falls requiring ICU management is increasing, and severe traumatic brain injury was responsible for the majority of deaths and for poor outcomes in survivors. In-hospital costs attributable to the care of these patients are high, and fewer than half were living independently at home at 12 months post-fall. A concerted public health campaign is required to alert the community to the potential consequences of this mechanism of injury. The use of helmets for ladder users in domestic settings, where occupational health and safety regulations are less likely to be applied, is strongly recommended to mitigate the risk of severe brain injury. The benefits of this simple strategy far outweigh any mild inconvenience for the wearer, and may prevent catastrophic injury.     

Baby Gate–Related Injuries Among Children in the United States, 1990–2010

ObjectiveBaby gates are one of the most widely used home safety products to protect children from home hazards. The objective was to describe the epidemiology of baby gate and barrier-associated injuries among children. It was hypothesized that injuries experienced by children ages ≤2 years and those >2 years were significantly different as a result of differences in gate interactions.MethodsA retrospective analysis was conducted by using nationally representative data from the National Electronic Injury Surveillance System. A total of 1188 actual cases were reviewed and national estimates generated.ResultsAn estimated 37,673 children were treated in emergency departments for injuries associated with gates, yielding an average of 1794 cases annually. The incidence of gate-related injuries increased significantly from 3.9 per 100,000 children in 1990 to 12.5 per 100,000 children in 2010 (P < .001). Patients were primarily boys (61.0%) and were <2 years of age (60.4%). Patients <2 years of age were most often injured by falls down stairs (odds ratio 6.72; 95% confidence interval 6.32–7.16) after the collapse of the gate. Patients aged 2 to 6 were most often injured by contact with the gate (odds ratio 2.03; 95% confidence interval 1.95–2.12), resulting in open wounds (55.4%) and soft-tissue injuries (24.2%).ConclusionsGiven the clear dichotomy between injury characteristics of patients aged <2 years and patients aged 2 to 6 years of age, as well as the prevalence of preventable injuries, greater efforts are needed to promote proper usage, ensure safety in product design, and increase awareness of age-related recommendations for use of gates.     

The effect of denture installation at mandibular rest position on unsteady motion of the centre of pressure in postural sway

Wearing dentures has been believed to decrease the instability of the postural sway using the total length of centre of pressure (CoP) trajectory or the magnitude of its variability. However, the physical aspects of the postural sway have not been taken into account while evaluating the CoP in patients who wear dentures. The CoP fluctuations are found to show a random walk process. Therefore, changes in the random movement of CoP caused by wearing dentures should be examined by nonlinear dynamics that enables analysis of the characteristics found in the random movement. We evaluated the effect of complete denture installation on CoP sway for twenty‐six edentulous patients by performing the following steps. First, we excluded subjects who did not show crossover in spectral analyses. Then, we evaluated the spectral characteristics and phase shifts of the velocities of CoP sway for the subjects who showed crossover. We found that wearing complete dentures decreased the fluctuations in the high‐frequency part of the power spectral density (PSD) and the phase shift in the mediolateral direction. On the other hand, we also found that the use of complete dentures decreased the fluctuations of PSD amplitude in the anteroposterior direction. From the point of view of the kinetic energy of the musculoskeletal system, we suggested that the use of complete dentures could reduce the energy consumption for the standing posture.