Internal fixation of pilon fractures of the distal radius.

When closed manipulation fails to restore articular congruity in comminuted, displaced fractures of the distal radius, open reduction and internal fixation is required. Results of surgical stabilization and articular reconstruction of these injuries are reviewed in this retrospective study of 49 patients with 52 displaced, intra-articular distal radius fractures. Forty-three patients (87%) with a mean age of 37 years (range of 17 to 79 years) were available for evaluation. The mean follow-up time was 38 months (range 22-69 months). When rated according to the Association for the Study of Internal Fixation (ASIF), 19 were type C2 and 21 were type C3. We devised an Injury Score System based on the initial injury radiographs to classify severely comminuted intra-articular fractures and to identify those associated with carpal injury (3 patients). Post-operative fracture alignment, articular congruity, and radial length were significantly improved following surgery (p < .01). Grip strength averaged 69% +/- 22% of the contralateral side, and the range of motion averaged 75% +/- 18% of the contralateral side post-operatively. A combined outcome rating system that included grip strength, range of motion, and pain relief averaged 76% +/- 19% of the contralateral side. There was a statistically significant decrease in the combined rating with more severe fracture patterns as defined by the ASIF system (p < .01), Malone classification (p < .03), and the Injury Score System (p < .001). The Injury Score System presented here, and in particular the number of fracture fragments, correlated most closely with outcome of all the classification systems studied. Operative treatment of these distal radius fractures with reconstruction of the articular congruity and correction of the articular surface alignment with internal fixation and/or external fixation, can significantly improve the radiographic alignment and functional outcome. Furthermore, the degree to which articular stepoff, gap between fragments, and radial shortening are improved by surgery is strongly correlated with improved outcome, even when the results are corrected for severity of initial injury, whereas correction of radial tilt or dorsal tilt did not correlate with improved outcome.     

The Probability of Death Following a Fracture of the Hip

All patients 45 years of age and over admitted with fractures of the hip to hospitals in the Atlantic Health Region of Nova Scotia were followed up over a two-year period. Actuarial methods were used to estimate survivorship from the date of fracture in 202 patients.Over-all, it was estimated that only 63.8% would be alive by one year post-fracture. This is 70% of the survival rate expected in the general population of corresponding age and sex. The period of greatest mortality was within the first 12 weeks. Patients surviving to one year could be considered “cured”, for after that their survivorship was at least as favourable as that of the “normal” population.Mortality was greatest in males in those 75 years of age and over and especially in patients who were relatively immobilized prior to their fracture. In this “dependent” group the relative survival ratio at one year was only 38%.     

When,Where and How Osteoporosis-Associated Fractures Occur: An Analysis from the Global Longitudinal Study of Osteoporosis in Women (GLOW)

Objective

To examine when, where and how fractures occur in postmenopausal women.

Methods

We analyzed data from the Global Longitudinal Study of Osteoporosis in Women (GLOW), including women aged ≥55 years from the United States of America, Canada, Australia and seven European countries. Women completed questionnaires including fracture data at baseline and years 1, 2 and 3.

Results

Among 60,393 postmenopausal women, 4122 incident fractures were reported (86% non-hip, non-vertebral [NHNV], 8% presumably clinical vertebral and 6% hip). Hip fractures were more likely to occur in spring, with little seasonal variation for NHNV or spine fractures. Hip fractures occurred equally inside or outside the home, whereas 65% of NHNV fractures occurred outside and 61% of vertebral fractures occurred inside the home. Falls preceded 68–86% of NHNV and 68–83% of hip fractures among women aged ≤64 to ≥85 years, increasing with age. About 45% of vertebral fractures were associated with falls in all age groups except those ≥85 years, when only 24% occurred after falling.

Conclusion

In this multi-national cohort, fractures occurred throughout the year, with only hip fracture having a seasonal variation, with a higher proportion in spring. Hip fractures occurred equally within and outside the home, spine fractures more often in the home, and NHNV fractures outside the home. Falls were a proximate cause of most hip and NHNV fractures. Postmenopausal women at risk for fracture need counseling about reducing potentially modifiable fracture risk factors, particularly falls both inside and outside the home and during all seasons of the year.     

The epidemiology of low- and high-energy distal radius fracture in middle-aged and elderly men and women in southern norway

Background

Distal radius is one of the most frequent sites for fractures in the elderly population. Despite this, there is a paucity of epidemiological data for distal radius fracture, in particular, distinguishing between high- and low-energy fractures. Our aim was to study the epidemiology of high- and low-energy distal radius fracture in middle-aged and elderly men and women in Southern Norway, and search for associates with high- or low-energy distal radius fracture in this population.

Methodology/Principal Findings

Patients with distal radius fractures aged ≥50 years were identified from all four hospitals in Southern Norway between 2004 and 2005. Age-adjusted and age-specific incidence rates for men and women were calculated, and potential associates with high- and low-energy distal radius fracture were explored both in univariate and multivariate analyses. A total of 799 individuals (118 men and 681 women) aged ≥50 years with low-energy and 84 (48 men and 36 women) with high-energy distal radius fracture were identified. The overall age-adjusted incidence rate per 10,000 person-years was 18.9 for men (low energy, 12.8 vs. high-energy, 6.1) and 75.1 for women (low energy, 71.1 vs. high energy, 4.0). In multivariate model, younger age, male gender, summer season, and living in a rural area were independently associated with an increased risk of high-energy fracture.

Conclusion

An approximately fourfold higher age-adjusted incidence rate for distal radius fracture was found among women, when compared with men. However, the proportion of patients with high-energy distal radius fracture was approximately fivefold higher in men than in women. Our data suggest that younger age, male gender, summer seasons, and living in rural areas are independent risk factors for increased risk of high-energy distal radius fracture.     

Prediction of osteoporotic fractures by postural instability and bone density.

OBJECTIVE--To investigate the utility of risk factors such as bone mineral density, lifestyle, and postural stability in the prediction of osteoporotic fractures. DESIGN--Longitudinal, epidemiological, and population based survey. SETTING--City of Dubbo, New South Wales. SUBJECTS--All residents of Dubbo aged > or = 60 on 1 January 1989. MAIN OUTCOME MEASURE--Incidence of fracture for individual subjects. RESULTS--The overall incidence of atraumatic fractures in men and women was 1.9% and 3.1% per annum respectively. The predominant sites of fracture were hip (18.9%), distal radius (18.5%), ribs and humerus (11.9% in each case), and ankle and foot (9.1% and 6.6% respectively). Major predictors of fractures in men and women were femoral neck bone mineral density, body sway, and quadriceps strength. Age, years since menopause, height, weight, and lifestyle factors were also correlated with bone mineral density and body sway and hence were indirect risk factors for fracture. Discriminant function analysis correctly identified 96% and 93% (sensitivities 88% and 81%) of men and women, respectively, who subsequently developed atraumatic fractures. Predictions based on this model indicated that a woman with a bone mineral density in the lowest quartile in the hip together with high body sway had a 8.4% probability of fracture per annum. This represented an almost 14-fold increase in risk of fracture compared with a woman in the highest bone mineral density quartile with low postural sway. An individual with all three predictors in the "highest risk" quartile had a 13.1% risk of fracture per annum. CONCLUSIONS--Bone mineral density, body sway, and muscle strength are independent and powerful synergistic predictors of fracture incidence.     

Statins and Hip Fracture Prevention – A Population Based Cohort Study in Women

Objective

To study the association of long-term statin use and the risk of low-energy hip fractures in middle-aged and elderly women.

Design

A register-based cohort study.

Setting

Finland.

Participants

Women aged 45–75 years initiating statin therapy between 1996 and 2001 with adherence to statins ≥80% during the subsequent five years (n = 40 254), a respective cohort initiating hypertension drugs (n = 41 610), and women randomly selected from the population (n = 62 585).

Main Outcome Measures

Incidence rate of and hazard ratio (HR) for low-energy hip fracture during the follow-up extending up to 7 years after the 5-year exposure period.

Results

Altogether 199 low-energy hip fractures occurred during the 135 330 person-years (py) of follow-up in the statin cohort, giving an incidence rate of 1.5 hip fractures per 1000 py. In the hypertension and the population cohorts, the rates were 2.0 per 1000 py (312 fractures per 157 090 py) and 1.0 per 1000 py (212 fractures per 216 329 py), respectively. Adjusting for a propensity score and individual variables strongly predicting the outcome, good adherence to statins for five years was associated with a 29% decreased risk (HR 0.71; 95% CI 0.58–0.86) of a low-energy hip fracture in comparison with adherent use of hypertension drugs. The association was of the same magnitude when comparing the statin users with the population cohort, the HR being 0.69 (0.55–0.87). When women with poor (<40%), moderate (40 to 80%), and good adherence (≥80%) to statins were compared to those with good adherence to hypertension drugs (≥80%) or to the population cohort, the protective effect associated with statin use attenuated with the decreasing level of adherence.

Conclusions

5-year exposure to statins is associated with a reduced risk of low-energy hip fracture in women aged 50–80 years without prior hospitalizations for fractures.     

Low Osteoporosis Treatment Initiation Rate in Women after Distal Forearm or Proximal Humerus Fracture: A Healthcare Database Nested Cohort Study

Treatment initiation rates following fragility fractures have often been reported to be low and in recent years numerous programs have been implemented worldwide to increase them. This study aimed at describing osteoporosis (OP) treatment initiation in a representative sample of women who were hospitalized for a distal forearm fracture (DFF) or proximal humerus fracture (PHF) in 2009–2011 in France. The data source was a nationwide sample of 600,000 individuals, extracted from the French National Insurance Healthcare System database. All women aged 50 years and older who were hospitalized for a DFF or PHF between 2009 and 2011 and who had not received any OP treatment in the preceding 12 months were included in a retrospective cohort study. OP treatments initiated during the year following the fracture were analyzed. From 2009 to 2011, 729 women were hospitalized for a DFF or a PHF and 284 were on OP treatment at the time of the fracture occurrence. Among the 445 women who had no prevalent OP treatment, 131 (29.4%) received supplementation treatment only (vitamin D and/or calcium) and 42 (9.4%) received a pharmacologic OP treatment in the year following their fracture. Pharmacological OP treatments included bisphosphonates (n = 21), strontium ranelate (n = 14), hormone replacement therapy (n = 4), or raloxifene (n = 3). General practitioners prescribed 75% of initial OP treatments. Despite the guidelines published in 2006 and the numerous initiatives to promote post-fracture OP treatment, OP treatment initiation rate in women who were hospitalized for a fragility fracture remained low in 2009–2011 in France.     

External Validation of the Garvan Nomograms for Predicting Absolute Fracture Risk: The Troms? Study

Background

Absolute risk estimation is a preferred approach for assessing fracture risk and treatment decision making. This study aimed to evaluate and validate the predictive performance of the Garvan Fracture Risk Calculator in a Norwegian cohort.

Methods

The analysis included 1637 women and 1355 aged 60+ years from the Tromsø study. All incident fragility fractures between 2001 and 2009 were registered. The predicted probabilities of non-vertebral osteoporotic and hip fractures were determined using models with and without BMD. The discrimination and calibration of the models were assessed. Reclassification analysis was used to compare the models performance.

Results

The incidence of osteoporotic and hip fracture was 31.5 and 8.6 per 1000 population in women, respectively; in men the corresponding incidence was 12.2 and 5.1. The predicted 5-year and 10-year probability of fractures was consistently higher in the fracture group than the non-fracture group for all models. The 10-year predicted probabilities of hip fracture in those with fracture was 2.8 (women) to 3.1 times (men) higher than those without fracture. There was a close agreement between predicted and observed risk in both sexes and up to the fifth quintile. Among those in the highest quintile of risk, the models over-estimated the risk of fracture. Models with BMD performed better than models with body weight in correct classification of risk in individuals with and without fracture. The overall net decrease in reclassification of the model with weight compared to the model with BMD was 10.6% (p = 0.008) in women and 17.2% (p = 0.001) in men for osteoporotic fractures, and 13.3% (p = 0.07) in women and 17.5% (p = 0.09) in men for hip fracture.

Conclusions

The Garvan Fracture Risk Calculator is valid and clinically useful in identifying individuals at high risk of fracture. The models with BMD performed better than those with body weight in fracture risk prediction.     

Osteoporosis Treatment After Osteoporotic Fractures: Data From a Single Medical Center

ObjectiveMost patients do not receive osteoporosis treatment after osteoporotic fracture. This study reviewed osteoporosis treatment after osteoporotic fractures in a center without a Fracture Liaison Service.MethodsWe identified all patients with hip, vertebral, humeral or radial fractures, evaluated in Meir Medical Center, in 2017. The exclusion criteria were not a Clalit Health Services member, high-energy fracture or 30-day postoperative mortality. The primary endpoint was osteoporosis drugs issued within 12 months of fracture. Secondary endpoints included bone densitometry and 1-year mortality.ResultsFive-hundred-eighty-two patients (average age 78.6 ± 11.1 years, 75.8% women) were included. There were 321 (55.5%) hip, 84 (14.1%) humeral, 33 (5.6%) vertebral, and 144 (24.7%) radial fractures. Osteoporosis drugs were issued to 26.5% of the patients; those with humeral fractures received the least (21.4%) and vertebral, the most (30.3%; P = .51). Bone densitometry was performed in 23.2% of patients. One-year mortality after hip fracture was 12.1%, followed by humeral (3.6%; P < .05). Logistic regression showed that previous treatment (odds ratio [OR] = 7.4; 95% confidence interval [CI] 3.6–15.2), bone densitometry (OR = 4.4; 95% CI 2.6–7.4) and endocrinology visit (OR = 2.6; 95% CI, 1.4–4.6) were the most important factors associated with treatment.ConclusionFewer than one third of patients received pharmacotherapy within 1 year after fracture. Because pharmacotherapy reduces future fractures and mortality, we recommend that medical staff who care for patients with fracture adopt practical and effective strategies to increase treatment rates among patients with osteoporotic fractures.     

闭合复位与切开复位治疗桡骨远端骨折的疗效对比

目的:探讨闭合复位与切开复位对桡骨远端骨折患者的临床疗效。方法:回顾性分析2013年6月至2014年3月我院收治的60例桡骨远端骨折患者,随机数字表法分为切开复位组和闭合复位组,每组30例。闭合复位组患者给予闭合复位小夹板或石膏固定治疗,切开复位组患者给予切开复位内固定术治疗。观察并比较两组患者治疗前后掌倾角、尺偏角以及桡骨长度、术中出血量和手术时间,骨折愈合时间以及患者临床疗效进行检测并比较。结果:与治疗前相比,治疗后患者的掌倾角、尺偏角、桡骨长度水平均升高(P0.05);与闭合复位组相比,切开复位组患者掌倾角、尺偏角、桡骨长度评分水平较高(P0.05),术中出血量、手术时间水平较高(P0.05),临床治疗的优良率较高(P0.05),两组患者的骨折愈合时间无显著差异(P0.05)。结论:与闭合复位相比,切开复位能够明显恢复桡骨远端骨折患者的掌倾角、尺偏角以及桡骨长度,但手术时间以及术中出血量较多,临床疗效较好,两组患者的骨折愈合时间无明显差异。     

FRACTURE OF THE METACARPAL SHAFT—A Method of Treatment

Anatomically, metacarpal fractures, when reduced, are not spontaneously stable. They require maintenance of this reduction because of the forces acting on the fragments. Closed methods of maintaining this reduction are ideal, but in selected cases, intramedullary fixation of the fracture, using the Kirschner wire, gives excellent results. The method under consideration does not disturb the fracture site itself, the Kirschner wire being introduced “blind.” Correct placement of the site of insertion of the wire, coupled with the rigid immobilization thus attained, gives excellent results in a high proportion of selected cases.     

Clinical Significance and Pathogenesis of Osteoporosis

The development of osteoporosis with advancing age in man is a widespread if not a universal phenomenon. The average loss between youth and old age amounts to about 15% of the skeleton but involves a much larger proportion of trabecular than of cortical bone.The principal clinical manifestation of osteoporosis is fracture, and three osteoporotic fracture syndromes can be defined: the lower forearm fracture, which predominantly affects women between the ages of 50 and 65; the fracture of the proximal femur, which affects both sexes over the age of 70; and the relatively rare vertebral crush fracture syndrome, which may present at any age but is most common in elderly women.The lower forearm fracture rate is inversely related to the mean normal lower forearm x-ray “density” of the wrist, which falls by about 30% in the 15 years following the menopause. This process, which is associated with corresponding trabecular bone loss elsewhere in the skeleton, is associated with a corresponding rise in the fasting urinary calcium excretion. Some degree of negative calcium balance, and consequent bone resorption, probably occurs in everyone during the later part of the night because calcium absorption is completed within about three to five hours of a meal. In postmenopausal women, however, the sensitivity of the bone to parathyroid hormone appears to be increased, and their nocturnal negative calcium balance therefore comes to exceed the positive balance which can be achieved during the waking hours.Femoral neck fractures in old people reflect the further progression of osteoporosis with advancing age since the fracture rate is inversely correlated with the mean thickness of the metacarpal cortex in the normal population. This progressive osteoporosis is associated with and could well result from a steady decline in calcium absorption which is at least partially attributable to vitamin-D deficiency and reversible on vitamin-D treatment.The vertebral crush fracture syndrome represents a severe degree of spinal osteoporosis which may be associated with relatively normal peripheral bones. It probably results from an accelerated negative calcium balance which mobilizes trabecular bone preferentially. Some of the factors which may contribute to this accelerated negative balance have been identified and include a reduced rate of bone turnover, impaired calcium absorption, and low oestrogen activity as judged by vaginal smears, but there may well be others as yet unidentified.     

FRAX?: Prediction of Major Osteoporotic Fractures in Women from the General Population: The OPUS Study

Purposes

The aim of this study was to analyse how well FRAX® predicts the risk of major osteoporotic and vertebral fractures over 6 years in postmenopausal women from general population.

Patients and methods

The OPUS study was conducted in European women aged above 55 years, recruited in 5 centers from random population samples and followed over 6 years. The population for this study consisted of 1748 women (mean age 74.2 years) with information on incident fractures. 742 (43.1%) had a prevalent fracture; 769 (44%) and 155 (8.9%) of them received an antiosteoporotic treatment before and during the study respectively. We compared FRAX® performance with and without bone mineral density (BMD) using receiver operator characteristic (ROC) c-statistical analysis with ORs and areas under receiver operating characteristics curves (AUCs) and net reclassification improvement (NRI).

Results

85 (4.9%) patients had incident major fractures over 6 years. FRAX® with and without BMD predicted these fractures with an AUC of 0.66 and 0.62 respectively. The AUC were 0.60, 0.66, 0.69 for history of low trauma fracture alone, age and femoral neck (FN) BMD and combination of the 3 clinical risk factors, respectively. FRAX® with and without BMD predicted incident radiographic vertebral fracture (n = 65) with an AUC of 0.67 and 0.65 respectively. NRI analysis showed a significant improvement in risk assignment when BMD is added to FRAX®.

Conclusions

This study shows that FRAX® with BMD and to a lesser extent also without FN BMD predict major osteoporotic and vertebral fractures in the general population.     

Multifaceted intervention to improve diagnosis and treatment of osteoporosis in patients with recent wrist fracture: a randomized controlled trial

Background

Older patients who experience a fragility fracture are at high risk of future fractures but are rarely tested or treated for osteoporosis. We developed a multifaceted intervention directed at older patients with wrist fractures (in the form of telephone-based education) and their physicians (in the form of guidelines endorsed by opinion leaders, supported by reminders) to improve the quality of osteoporosis care.

Methods

In a randomized controlled trial with blinded ascertainment of outcomes, we compared our intervention with usual care (provision of printed educational materials to patients). Eligible patients were those older than 50 years of age who had experienced a wrist fracture and were seen in emergency departments and fracture clinics; we excluded those who were already being treated for osteoporosis. The primary outcome was bisphosphonate treatment within 6 months after the fracture. Secondary outcomes included bone mineral density testing, “appropriate care” (consisting of bone mineral density testing with treatment if bone mass was low) and quality of life.

Results

We screened 795 patients for eligibility and randomly assigned 272 to the intervention (137 patients) or control (135 patients) group. The median age was 60 years; 210 (77%) of the subjects were women, and 130 (48%) reported a previous fracture as an adult. Six months after the fracture, 30 (22%) of the intervention patients, as compared with 10 (7%) of the control patients, were receiving bisphosphonate therapy for osteoporosis (adjusted relative risk [RR] 2.6, 95% confidence interval [CI] 1.3–5.1, p = 0.008). Intervention patients were more likely than control patients to undergo bone mineral density testing (71/137 [52%] v. 24/135 [18%]; adjusted RR 2.8, 95% CI 1.9–4.2, p < 0.001) and to receive appropriate care (52/137 [38%] v. 15/135 [11%]; adjusted RR 3.1, 95% CI 1.8–5.3, p < 0.001). There were no differences between the groups in other outcomes. One patient died, and 4 others experienced recurrent fracture.

Interpretation

A multifaceted intervention directed at high-risk patients and their physicians substantially increased rates of testing and treatment for osteoporosis. Nevertheless, more than half of the patients in the intervention group were not receiving appropriate care 6 months after their fracture, which suggests that additional strategies should be explored. (ClinicalTrials.gov trial register no. NCT00152321.)Osteoporosis is a common, chronic and costly condition affecting at least 25% of women and 12% of men over 50 years of age.^1–3 Without better prevention strategies, the incidence of and costs related to osteoporotic fractures are expected to increase by 50% over the next 2 decades.³ Case-finding and secondary prevention (e.g., by identifying patients who have experienced a fragility fracture, ensuring that their bone mineral density is tested and offering efficacious osteoporosis treatments to those with low bone mass) constitute the most cost-effective strategy for reducing future fractures.^4–6An obvious target group for case-finding consists of older patients who experience a wrist fracture. Wrist fracture is the most common symptomatic fracture related to osteoporosis; its occurrence is a powerful forecaster of future fractures, and these fractures typically occur 10–20 years before the more devastating osteoporosis-related fractures of the spine or the hip.⁷ Unfortunately, although most older patients with wrist fractures have low bone mass and are eligible for treatment,^4,7 less than about 10% to 20% are tested or treated for osteoporosis in the 6 to 12 months after a wrist fracture.^4–9We previously reported a nonrandomized study of an intervention that incorporated patient education, physician reminders and treatment guidelines endorsed by opinion leaders, to improve osteoporosis treatment in patients with wrist fractures; in that study, which involved 102 patients, the rate of treatment was 40% in the intervention group but only 10% in the group receiving usual care.⁷ Several concerns were raised about the internal and external validity of that small study, so we conducted a randomized controlled trial of the intervention, which is reported here.     

Cross-sectional geometrical properties of distal radius and ulna in large, medium and toy breed dogs

Fractures of the distal radius and the ulna are the third most common fractures in dogs. Toy and miniature breeds have a propensity to develop antebrachial fractures after falling or jumping. Most affect the distal third of both bones involving between 15% and 37% of the radial length. Larger dogs, instead, typically sustain hyperextension injuries to the carpus. The causative mechanisms for this fracture prevalence in toy dogs are unknown. Breed-related changes in bone geometry and/or mineral density have been suggested as possible etiologic factors. In a multifactorial study, the main etiological factors potentially responsible for determining susceptibility to fractures in toy breeds are considered. The aim of this first study is to evaluate the geometric bone features in different dog sizes. The cortical bone cross-sectional properties along the length of the right radius and the ulna of 28 dogs from three different size categories have been quantified by computerized tomographic scanning. Geometrical cross-sectional parameters were measured and normalized to radial length to allow intergroup comparisons. Discriminant analysis was used to classify the observations into different groups. Through statistical analysis of the normalized values, significant differences in cross-sectional properties of different bone sizes were found. The results suggest that, when proportionally loaded, the antibrachii of toy breed dogs are more susceptible to fracture than those of large breed dogs due to morphological differences.     

Prevalence of Sarcopenia and Its Relationship with Sites of Fragility Fractures in Elderly Chinese Men and Women

Objective

Sarcopenia might be associated with bone fragility in elderly individuals. This study aimed to investigate the prevalence of sarcopenia and its association with fragility fracture sites in elderly Chinese patients.

Methods

Patients (322 men and 435 women) aged 65–94 years and with a history of fragility fractures in the ankle, wrist, vertebrae or hip, and healthy men (n = 1263) and women (n = 1057) aged 65–92 years without a history of fractures were enrolled. Whole-body dual energy X-ray absorptiometry was used to analyze skeletal muscle mass index (SMI), fat mass and bone mineral density. Sarcopenia was defined as SMI less than two standard deviations below the mean of a young reference group.

Results

Sarcopenia occurrence varied with fracture location. Sarcopenia was more common in females with vertebral and hip fractures and in men with hip and ankle fractures than in the non-fracture group). Sarcopenia was significantly more prevalent in men with wrist, hip and ankle fractures than in women. SMI was correlated with BMD in different fracture groups. Logistic regression analyses revealed that lower SMI was associated with an increased risk of hip fracture both in men and women and ankle fracture in men.

Discussion

Sarcopenia may be an independent risk factor for hip and ankle fractures in men, and for hip fractures in women.     

USP9X Enhances the Polarity and Self-Renewal of Embryonic Stem Cell-derived Neural Progenitors

The substrate-specific deubiquitylating enzyme USP9X is a putative “stemness” gene expressed in many progenitor cell populations. To test its function in embryonic stem cell-derived neural progenitor/stem cells, we expressed USP9X from a Nestin promoter. Elevated USP9X levels resulted in two phenomena. First, it produced a dramatically altered cellular architecture wherein the majority (>80%) of neural progenitors was arranged into radial clusters. These progenitors expressed markers of radial glial cells and were highly polarized with adherens junction proteins (N-cadherin, β-catenin, and AF-6) and apical markers (Prominin1, atypical protein kinase C-ζ) as well as Notch, Numb, and USP9X itself, concentrated at the center. The cluster centers were also devoid of nuclei and so resembled the apical end-feet of radial progenitors in the neural tube. Second, USP9X overexpression caused a fivefold increase in the number of radial progenitors and neurons, in the absence of exogenous growth factors. 5-Bromo-2′-deoxyuridine labeling, as well as the examination of the brain lipid-binding protein:βIII-tubulin ratio, indicated that nestin-USP9X enhanced the self-renewal of radial progenitors but did not block their subsequent differentiation to neurons and astrocytes. nestin-USP9X radial progenitors reformed clusters after passage as single cells, whereas control cells did not, suggesting it aids the establishment of polarity. We propose that USP9X-induced polarization of these neural progenitors results in their radial arrangement, which provides an environment conducive for self-renewal.     

Perimenopausal risk of falling and incidence of distal forearm fracture.

A postal survey of 2000 women and 2000 men sampled from the electoral roll in Oxford was undertaken to ascertain whether changes with age in the risk of falling might explain the stepwise increases in age specific incidence rates of distal forearm fracture which occur in women at around the age of 50. Corrected response rates were 83% for women and 72% for men. In women, but not in men, there was a rise in the risk of falling from 45 years, peaking in the 55-59 year age group, and sinking to a nadir at ages 70-74. In both sexes rates rose in extreme old age. These variations were not attributable to preferential response from people who had suffered a fracture. It is concluded that changes in the risk of falling interact with osteoporosis to produce a perimenopausal rise in the incidence of forearm fractures and contribute to the fluctuations in incidence of these fractures in old age.     

Prediction of Colles’ fracture load in human radius using cohesive finite element modeling

Osteoporotic and age-related fractures are a significant public health problem. One of the most common osteoporotic fracture sites in the aging population is distal radius. There is evidence in the literature that distal radius fractures (Colles’ fracture) are an indicative of increased risk of future spine and hip fractures. In this study, a nonlinear fracture mechanics-based finite element method is applied to human radius to assess its fracture load as a function of cortical bone geometry and material properties. Seven three-dimensional finite element models of radius were created and the fracture loads were determined by using cohesive finite element modeling which explicitly represents the crack and the fracture process zone behavior. The fracture loads found in the simulations (731–6793 N) were in the range of experimental values reported in the literature. The fracture loads predicted by the simulations decreased by 4–5% per decade based only on material level changes and by 6–20% per decade when geometrical changes were also included. Cortical polar moment of inertia at 15% distal radius showed the highest correlation to fracture load (r²=0.97). These findings demonstrate the strength of fracture mechanics-based finite element modeling and show that combining geometrical and material properties provides a better assessment of fracture risk in human radius.