The effect of surgical timing on the outcome of patients with neck of femur fracture

Aims: To investigate the effect of surgical timing (in hours versus after hours and weekdays versus weekends) on the outcome of patients with neck of femur fracture. Methods: Patients who were admitted to a single tertiary referral hospital for surgical management of femoral neck fractures over a continuous period from 1/11/2002 to 12/7/2012 were identified from medical records and the operating theatre database. Results: A consecutive series of 2334 patients were included in the study. Of the patients who underwent surgery during the weekday and during usual hours, 18 % (207/1135) experienced an adverse event, compared to 16 % (193/1199) outside of these times. The difference between the two groups was not significant (p = 0.17). The same conclusion was made for the comparison between those who had surgery during the week with those who had surgery on the weekend (17 %, 267/1546 and 17 %, 133/788, respectively, p > 0.05). The proportion of patients who underwent surgery during hours that experienced an adverse event was significantly higher than those undergoing surgery out of hours (18 %, 327/1789 and 13 %, 73/545, respectively, p = 0.0081). When adjusted for age, ASA score and pre-operative stay, there was no statistical difference between those different sub-groups. Conclusions: There was no difference in the rates of adverse events between patients who had surgery during hours and weekdays with those who had surgery after hours or weekends. The careful selection of patients with appropriate hospital staff, resources and adequate theatre access, surgery during after hours and weekends may be safely considered to prevent a delay in surgical treatment for patient with neck of femur fracture.

Lifetime sport and leisure activity participation is associated with greater bone size, quality and strength in older men

Introduction: It remains uncertain whether long-term participation in regular weight-bearing exercise confers an advantage to bone structure and strength in old age. The aim of this study was to investigate the relationship between lifetime sport and leisure activity participation on bone material and structural properties at the axial and appendicular skeleton in older men (>50 years).

Methods: We used dual-energy X-ray absorptiometry (DXA) to assess hip, spine and ultradistal (UD) radius areal bone mineral density (aBMD) (n=161), quantitative ultrasound (QUS) to measure heel bone quality (n=161), and quantitative computed tomography (QCT) to assess volumetric BMD, bone geometry and strength at the spine (L₁–L₃) and mid-femur (n=111). Current (>50+ years) and past hours of sport and leisure activity participation during adolescence (13–18 years) and adulthood (19–50 years) were assessed by questionnaire. This information was used to calculate the total time (min) spent participating in sport and leisure activities and an osteogenic index (OI) score for each participant, which provides a measure of participation in weight-bearing activities.

Results: Regression analysis revealed that a greater lifetime (13–50+ years) and mid-adulthood (19–50 years) OI, but not total time (min), was associated with a greater mid-femur total and cortical area, cortical bone mineral content (BMC), and the polar moment of inertia (I _p) and heel VOS (p ranging from <0.05 to <0.01). These results were independent of age, height (or femoral length) and weight (or muscle cross-sectional area). Adolescent OI scores were not found to be significant predictors of bone structure or strength. Furthermore, no significant relationships were detected with areal or volumetric BMD at any site. Subjects were then categorized into either a high (H) or low/non-impact (L) group during adolescence (13–18 years) and adulthood (19–50+ years) according to their OI scores during each of these periods. Three groups were subsequently formed to reflect weight-bearing impact categories during adolescence and then adulthood: LL, HL and HH. Compared to the LL group, mid-femur total and cortical area, cortical BMC and I _p were 6.5–14.2% higher in the HH group. No differences were detected between the LL and HL groups.

Conclusions: In conclusion, these findings indicate that long-term regular participation in sport and leisure activities categorized according to an osteogenic index [but not the total time (min) spent participating in all sport and leisure activities] was an important determinant of bone size, quality and strength, but not BMD, at loaded sites in older men. Furthermore, continued participation in weight-bearing exercise in early to mid-adulthood appears to be important for reducing the risk of low bone strength in old age.

Long-term effects of calcium-vitamin-D3-fortified milk on bone geometry and strength in older men

The long-term effects of calcium and vitamin D supplementation on bone material and structural properties in older men are not known. The aim of this study was to examine the effects of high calcium (1000 mg/day)- and vitamin-D3 (800 IU/day)-fortified milk on cortical and trabecular volumetric BMD (vBMD) and bone geometry at the axial and appendicular skeleton in men aged over 50 years. One hundred and eleven men who were part of a larger 2-year randomized controlled trial had QCT scans of the mid-femur and lumbar spine (L1–L3) to assess vBMD, bone geometry and indices of bone strength [polar moment of inertia (Ipolar)]. After 2 years, there were no significant differences between the milk supplementation and control group for the change in any mid-femur or L1–L3 bone parameters for all men aged over 50 years. However, the mid-femur skeletal responses to the fortified milk varied according to age, with a split of ≤62 versus >62 years being the most significant for discriminating the changes between the two groups. Subsequent analysis revealed that, in the older men (>62 years), the expansion in mid-femur medullary area was 2.8% (P < 0.01) less in the milk supplementation compared to control group, which helped to preserve cortical area in the milk supplementation group (between group difference 1.1%, P < 0.01). Similarly, for mid-femur cortical vBMD and Ipolar, the net loss was 2.3 and 2.8% less in the milk supplementation compared to control group (P < 0.01 and <0.001, respectively). In conclusion, calcium–vitamin-D3-fortified milk may represent an effective strategy to maintain bone strength by preventing endocortical bone loss and slowing the loss in cortical vBMD in elderly men.

Regional specificity of exercise and calcium during skeletal growth in girls: a randomized controlled trial

Combining exercise with calcium supplementation may produce additive or multiplicative effects at loaded sites; thus, we conducted a single blind, prospective, randomized controlled study in pre- and early-pubertal girls to test the following hypotheses. (1) At the loaded sites, exercise and calcium will produce greater benefits than exercise or calcium alone. (2) At non-loaded sites, exercise will have no benefit, whereas calcium with or without exercise will increase bone mass over that in exercise alone or no intervention. Sixty-six girls aged 8.8 ± 0.1 years were randomly assigned to one of four study groups: moderate-impact exercise with or without calcium or low-impact exercise with or without calcium. All participants exercised for 20 minutes, three times a week and received Ca-fortified (434 ± 19 mg/day) or non-fortified foods for 8.5 months. Analysis of covariance (ANCOVA) was used to determine interaction and main effects for exercise and calcium on bone mass after adjusting for baseline bone mineral content and growth in limb lengths. An exercise-calcium interaction was detected at the femur (7.1%, p < 0.05). In contrast, there was no exercise-calcium interaction detected at the tibia-fibula; however, there was a main effect of exercise: bone mineral content increased 3% more in the exercise than non-exercise groups (p < 0.05). Bone mineral content increased 2-4% more in the calcium-supplemented groups than the non-supplemented groups at the humerus (12.0% vs. 9.8%, respectively, p < 0.09) and radius-ulna (12.6% vs. 8.6%, respectively, p < 0.01). In conclusion, greater gains in bone mass at loaded sites may be achieved when short bouts of moderate exercise are combined with increased dietary calcium, the former conferring region-specific effects and the latter producing generalized effects.

Exercise and calcium combined results in a Greater osteogenic effect than either factor alone: a blinded randomized placebo-controlled trial in boys

We examined the combined effects of exercise and calcium on BMC accrual in pre- and early-pubertal boys. Exercise and calcium together resulted in a 2% greater increase in femur BMC than either factor alone and a 3% greater increase in BMC at the tibia–fibula compared with the placebo group. Increasing dietary calcium seems to be important for optimizing the osteogenic effects of exercise.

Introduction: Understanding the relationship between exercise and calcium during growth is important given that the greatest benefits derived from these factors are achieved during the first two decades of life. We conducted a blinded randomized-controlled exercise–calcium intervention in pre- and early-pubertal boys to test the following hypotheses. (1) At the loaded sites (femur and tibia–fibula), exercise and calcium will produce greater skeletal benefits than either exercise or calcium alone. (2) At nonloaded sites (humerus and radius–ulna), there will be an effect of calcium supplementation.

Materials and Methods: Eighty-eight pre- and early-pubertal boys were randomly assigned to one of four study groups: moderate impact exercise with or without calcium (Ca) (Ex + Ca and Ex + placebo, respectively) or low impact exercise with or without Ca (No-Ex + Ca and No-Ex + Placebo, respectively). The intervention involved 20 minutes of either moderate- or low-impact exercise performed three times a week and/or the addition of Ca-fortified foods using milk minerals (392 ± 29 mg/day) or nonfortified foods over 8.5 months. Analysis of covariance was used to determine the main and combined effects of exercise and calcium on BMC after adjusting for baseline BMC.

Results: At baseline, no differences were reported between the groups for height, weight, BMC, or bone length. The increase in femur BMC in the Ex + Ca group was 2% greater than the increase in the Ex + placebo, No-Ex + Ca, or No-Ex + Placebo groups (all p < 0.03). At the tibia–fibula, the increase in BMC in the Ex + Ca group was 3% greater than the No-Ex + placebo group (p < 0.02) and 2% greater than the Ex + Placebo and the No-Ex + Ca groups (not significant). No effect of any group was detected at the humerus, ulna–radius, or lumbar spine for BMC, height, bone area, or volume.

Conclusions: In this group of normally active boys with adequate calcium intakes, additional exercise and calcium supplementation resulted in a 2–3% greater increase in BMC than controls at the loaded sites. These findings strengthen the evidence base for public health campaigns to address both exercise and dietary changes in children for optimizing the attainment of peak BMC.

Diet and habitat of the powerful owl (Ninox strenua) living near Melbourne

The diet of Powerful Owls (Ninox strenua) living at Christmas Hills, 35km north-east of Melbourne was examined by analysis of 686 regurgitated pellets collected over two years. An aid was also developed to help identify potential mammalian prey species based on hair and skeletal characteristics. The following features were found to be most useful in distinguishing between the three species of arboreal marsupials - Common Ringtail Possum (Pseudocheirus peregrinus), Common Brushtail Possum (Trichosurus vulpecula) and Sugar Glider (Petaurus breviceps): - Cross-sectional width of primary guard hairs. - The size and shape of the nasal, frontal, parietal and squamosal bones of the skull. - Dentition. The size and shape of the upper incisor, canine and premolar teeth. The size and shape of the lower incisor and premolar teeth. - The size of the humerus. The Sugar Glider has a much smaller humerus than that of the Common Ringtail Possum and the Common Brushtail Possum. In the Common Brushtail Possum the entepicondyle ends in a very sharp point but the Common Ringtail Possum this point is not as sharp. - The Common Ringtail Possum’s femur has a very prominent trochanter which projects further than that in the Common Brushtail Possum. The femur of the Sugar Glider is distinguished by having a very large depression between the condyle and the trochanter. - The Common Brushtail Possum’s scapula has a narrower lower blade (relative to length) than that in the Common Ringtail Possum. The scapula of the Sugar Glider is smaller in size than that of the other two possums.The pelvic girdle Of the Common Brushtail Possum has a much wider ischium than those of the Common Brushtail Possum and the Sugar Glider. The ilium of the Sugar is much narrower and smaller than that of the other two possums Mammalian prey was found in 89%, insects in 13% and birds in 10% of the pellets. Of the mammals, Common Ringtail Possums occurred most frequently in the pellets over the year. There was no seasonal difference in the frequency of occurrence of Common Ringtail Possums and Sugar Gliders in pellets. However, Common Brushtail Possums were more likely to be taken in spring than in the other seasons. More adult Common Ringtail Possums were taken as prey than were other age classes over the year, except in summer when high numbers of young were consumed by the owls. The habitat of the Powerful Owl was examined by ground surveys and spotlight surveys in sixteen sites within the Warrandyte-Kinglake Nature Conservation Link. Four categories of survey sites were chosen with the following features. Category A - Sites with a dense understorey of shrubs and small trees, as well as many old trees (>10/ha) which might be suitable for nest hollows. Category B - Sites which lacked a dense understorey of shrubs and small trees and containing few or no old trees suitable for nest hollows. Category C - Sites with a dense understorey of shrubs and small trees but containing few or no old trees suitable for nest hollows. Category D - Sites which lacked a dense understorey of shrubs and small trees but having old trees (>10/ha) which might be suitable for nest hollows. High prey densities strongly correlated with the presence of hollows at these sites. In the light of the results, management recommendations were made for the future conservation of the Powerful Owls living at Christmas Hills. The following recommendations were particularly important: 1. Cleared or semi - cleared land within the Warrandyte Kinglake Nature Conservation Link be revegetated using indigenous species of eucalypts and waffles in order to provide a contiguous native forest corridor for the movement of possums and gliders between the Yarra River Valley and the Kinglake Plateau. 2. Continued planting of Eucalyptus spp. and Acacia spp. in the forested areas of the Warrandyte-Kinglake Nature Conservation Link. 3. Continued protection of healthy living trees to provide a continuous supply of hollow trees. 4. No falling of dead standing trees for firewood collecting as these can provide nest hollows for prey species of the Powerful Owl.

Skeletal benefits after long-term retirement in former elite female gymnasts

Bone strength benefits after long-term retirement from elite gymnastics in terms of bone geometry and volumetric BMD were studied by comparing retired female gymnasts to moderately active age-matched women. In a cross-sectional study, 30 retired female gymnasts were compared with 30 age-matched moderately active controls. Bone geometric and densitometric parameters were measured by pQCT at the distal epiphyses and shafts of the tibia, femur, radius, and humerus. Muscle cross-sectional areas were assessed from the shaft scans. Independent t-tests were conducted on bone and muscle variables to detect differences between the two groups. The gymnasts had retired for a mean of 6.1 ± 0.4 yr and were engaged in ≤2 h of exercise per week since retirement. At the radial and humeral shafts, cortical cross-sectional area (CSA), total CSA, BMC, and strength strain index (SSIpol) were significantly greater (13–38%, p ≤ 0.01) in the retired gymnasts; likewise, BMC and total CSA were significantly greater at the distal radius (22–25%, p ≤ 0.0001). In the lower limbs, total CSA and BMC at the femur and tibia shaft were greater by 8–11%, and trabecular BMD and BMC were only greater at the tibia (7–8%). Muscle CSA at the forearm and upper arm was greater by 15–17.6% (p ≤ 0.001) but was not different at the upper and lower leg. Past gymnastics training is associated with greater bone mass and bone size in women 6 yr after retirement. Skeletal benefits were site specific, with greater geometric adaptations (greater bone size) in the upper compared with the lower limbs.

Pulse-lavage brushing followed by hydrogen peroxide-gauze packing for bone-bed preparation in cemented total hip arthroplasty : a bovine model

To compare the effectiveness of pulse-lavage brushing followed by hydrogen peroxide-gauze packing with either technique alone or normal-saline irrigation in bone-bed preparation for cemented total hip arthroplasty. 44 fresh-frozen ox femoral canals were prepared for cemented total hip arthroplasty using 4 techniques: normal-saline irrigation, pulse-lavage brushing, hydrogen peroxide-soaked gauze packing, and a combination of the latter 2 techniques. The maximum tensile pull-out force required to separate the prosthesis from the femoral canal was measured as an indicator of the strength of the cement-bone interface. The mean pull-out force to separate the prosthesis from the femoral canal was significantly higher in specimens prepared with pulse-lavage brushing followed by hydrogen peroxide-soaked gauze packing or pulse-lavage brushing alone than those prepared with normal-saline irrigation or hydrogen peroxide-soaked gauze packing alone 300(p<0.001). Pulse-lavage brushing is more effective at cleansing the femoral canal and increasing mechanical strength at the cement-bone interface than preparation with normal-saline irrigation or hydrogen peroxide-soaked gauze packing.

Effects of lifetime loading history on cortical bone density and its distribution in middle-aged and older men

We have reported previously that long-term participation of weight-bearing exercise is associated with increased QCT-derived cortical bone size and strength in middle-aged and older men, but not whole bone cortical volumetric BMD. However, since bone remodeling and the distribution of loading-induced strains within cortical bone are non-uniform, the aim of this study was to examine the effects of lifetime loading history on cortical bone mass distribution and bone shape in healthy community dwelling middle-aged and older men. We used QCT to assess mid-femur and mid-tibia angular bone mass distribution around its center (polar distribution), the bone density distribution through the cortex (radial distribution), and the ratio between the maximum and minimum moments of inertia (I_max/I_min ratio) in 281 men aged 50 to 79 years. Current (> 50 years) and past (13–50 years) sport and leisure time activity was assessed by questionnaire to calculate an osteogenic index (OI) during adolescence and adulthood. All men were then categorized into a high (H) or low/non impact (L) group according to their OI scores in each period. Three contrasting groups were then formed to reflect weight-bearing impact categories during adolescence and then adulthood: H–H, H–L and L–L. For polar bone mass distribution, bone deposition in the anterolateral, medial and posterior cortices were 6–10% greater at the mid-femur and 9–24% greater at mid-tibia in men in the highest compared to lowest tertile of lifetime loading (p < 0.01– < 0.001). When comparing the influence of contrasting loading history during adolescence and adulthood, there was a graded response between the groups in the distribution of bone mass at the anterior-lateral and posterior regions of the mid-tibia (H–H > H–L > L–L). For radial bone density distribution, there were no statistically significant effects of loading at the mid-femur, but a greater lifetime OI was associated with a non-significant 10–15% greater bone density near the endocortical region of the mid-tibia. In conclusion, a greater lifetime loading history was associated with region-specific adaptations in cortical bone density.

Prevalence of osteoporosis in Australian women : Geelong Osteoporosis Study

To evaluate the prevalence of osteoporosis at various sites among Australian women, cross-sectional bone mineral density (BMD) data for adult females was obtained from an age-stratified population-based sample (n = 1494; 20–94 yr) drawn at random from the Barwon Statistical Division, a population characteristic of Australia. Age- and weight- (and for three sites, height) matched reference ranges for BMD at the lumbar spine, proximal femur, forearm, and total body were developed using regression techniques. The cutoff BMD level for osteoporosis at the PA spine was 0.917 g/cm² and 0.713 g/cm² at the femoral neck according to the World Health Organization (WHO) guidelines. The upper cutoff level for osteopenia was 1.128 g/cm² at the PA spine and 0.913 g/cm² for the femoral neck. The proportion of Australian women categorized as having osteoporosis at the PA spine, femoral neck, or midforearm ranged from 0.9% among those aged 40–44 yr to 87.0% for those older than 79 yr. This study provides reference data representative of the Australian female population. A large proportion of elderly Australian women has osteoporosis according to the WHO guidelines.

Reference ranges for bone densitometers adopted Australia-wide : Geelong Osteoporosis Study

Bone densitometry reports a measure of fracture risk in comparison with young adults (T-scores) and age-matched peers (Z-scores). To date, each manufacturer has provided its own reference range resulting in lack of uniformity. The Australia and New Zealand Bone and Mineral Society and Osteoporosis Australia have recognized the need to standardize the reference range and have recommended that data generated by the Geelong Osteoporosis Study (GOS) be used Australia-wide. The GOS recruited a random, population-based sample of adult women and measured bone mineral density (BMD) at the proximal femur and spine using a Lunar DPX-L. These data were used to establish reference ranges for Lunar machines and, using conversion equations, for Norland and Hologic machines. The new standardized Australian reference ranges for BMD will enable consistent diagnosis of osteoporosis and categorization of fracture risk across different types of densitometers.

Application of epidemiology to change health policy : defining age-related thresholds of bone mineral density for primary prevention of fracture

In Australia, benefits for antifracture therapies have been available for patients with osteoporosis and a prior fracture. No benefits were available to those with no prior fracture. We aimed to define, in women with no prior fracture, age-related thresholds of bone mineral density (BMD) associated with fracture risk equivalent to that of women with prior fracture and osteoporosis. A case-control study of women (≥50 yr) was conducted, including 291 fracture cases and 823 controls. BMD was measured at the proximal femur and posterior anterior (PA) spine. A fracture risk score (FRS) for the group with no prior fracture was calculated with discriminant analysis. The thresholds for equivalent fracture risk between those with no prior fracture and those with prior fracture were assessed using logistic regression. Increasing the FRS to +0.98 in women with no prior fracture resulted in equivalent odds of sustaining a fracture to those with prior fracture and osteoporosis. The corresponding T-score thresholds at the spine were −4.6 at 50 yr, −3.9 at 60 yr, −3.1 at 70 yr, and −2.4 at 80 yr. The femoral neck T-score thresholds were lower by 0.5 standard deviation. The high-risk individuals defined by this study should be considered for primary fracture prevention therapy.

Fracture thresholds revisited : Geelong Osteoporosis Study

Osteoporosis, in the absence of fracture, is defined as a deficit in bone mineral density (BMD) of 2.5 SD or more below the young adult reference mean in postmenopausal Caucasian populations. BMD is a measure of fracture risk but not the sole predictor. We have assessed a combination of easily accessible measures of age, height, weight, and BMD to improve fracture risk assessment. Women with low trauma fractures and a control group were recruited from south-eastern Australia. Discriminant analysis derived multivariate equations that assessed fracture risk. Age was not in the best models at the spine and forearm sites. Weight and height contributed to the relationship for the forearm sites only. At the proximal femur, the BMD level that separates fracture cases from nonfracture cases, increases with age. These separation levels of BMD were higher than the WHO's level of osteoporosis (T-score < −2.5 SD) at ages older than 62 years. This increasing BMD threshold with age suggests that other age-related risk factors assume increasing importance among the elderly.

Serum leptin levels are associated with bone mass in nonobese women

Both serum leptin and bone mineral density are positively correlated with body fat, generating the hypothesis that leptin may be a systemic and/or local regulator of bone mass. We investigated 214 healthy, nonobese Australian women aged 20-91 yr. Bone mineral content, projected bone area, and body fat mass were measured by dual energy x-ray absorptiometry and fasting serum leptin levels by RIA. Associations between bone mineral content (adjusted for age, body weight, body fat mass, and bone area) and the natural logarithm of serum leptin concentrations were analyzed by multiple regression techniques. There was a significant positive association at the lateral spine, two proximal femur sites (Ward's triangle and trochanter), and whole body (partial r² = 0.019 to 0.036; all P < 0.05). Similar trends were observed at the femoral neck and posterior-anterior-spine. With bone mineral density the dependent variable (adjusted for age, body weight, and body fat mass), the association with the natural logarithm of leptin remained significant at the lateral spine (partial r² = 0.030; P = 0.011), was of borderline significance at the proximal femur sites (partial r² = 0.012 to 0.017; P = 0.058 to 0.120), and was not significant at the other sites. Our results demonstrate an association between serum leptin levels and bone mass consistent with the hypothesis that circulating leptin may play a role in regulating bone mass.

Femoral neck dimensions are unlikely to be associated with age at menarche

Hip axis length (HAL) has been reported as an independent risk factor for hip fracture. Later puberty may increase bone size because of delayed epiphyseal fusion. We sought to identify associations between bone size at the proximal femur with age at menarche and other indices of growth such as stature. Femoral neck dimensions were measured from dual-energy X-ray absorptiometry scans of the proximal femur in a random sample of 203 premenopausal Caucasian women (age 20–30 years). There were no associations between age at menarche and HAL, femoral axis length (FAL) or femoral neck width (FNW). Age at menarche was associated with height (r= 0.2, p= 0.02). Variations in HAL, FAL and FNW do not appear to be related to age at menarche.