Biomechanics of the hip and birth in early Homo

A complex of traits in the femur and pelvis of Homo ereclus and early “erectus-like” specimens has been described, but never satisfactorily explained. Here the functional relationships between pelvic and femoral structure in humans are explored using both theoretical biomechanical models and empirical tests within modern samples of diverse body form (Pecos Amerindians, East Africans). Results indicate that a long femoral neck increases mediolateral bending of the femoral diaphysis and decreases gluteal abductor and hip joint reaction forces. Increasing biacetabular breadth along with femoral neck length further increases M-L bending of the femoral shaft and maintains abductor and joint reaction forces at near “normal” levels. When compared to modern humans, Homo erectus and early “erectus-like” specimens are characterized by a long femoral neck and greatly increased M-L relative to A-P bending strength of the femoral shaft, coupled with no decrease in hip joint size and a probable increase in abductor force relative to body size. All of this strongly suggests that biacetabular breadth as well as femoral neck length was relatively large in early Homo. Several features preserved in early Homo partial hip bones also indicate that the true (lower) pelvis was very M-L broad, as well as A-P narrow. This is similar to the lower pelvic shape of australopithecines and suggests that nonrotational birth, in which the newborn's head is oriented transversely through the pelvic outlet, characterized early Homo as well as Australopithecus. Because M-L breadth of the pelvis is constrained by other factors, this may have limited increases in cranial capacity within Homo until rotational birth was established during the late Middle Pleistocene. During or after the transition to rotational birth biacetabular breadth decreased, reducing the body weight moment arm about the hip and allowing femoral neck length (abductor moment arm) to also decrease, both of which reduced M-L bending of the proximal femoral shaft. Variation in femoral structural properties within early Homo and other East African Early Pleistocene specimens has several taxonomic and phylogenetic implications. © 1995 Wiley-Liss, Inc.     

Biomechanical and clinical alterations of the hip joint following femoral neck fracture and implantation of bipolar hip endoprosthesis

The implantation of a bipolar partial hip endoprosthesis is a treatment of choice for displaced medial femoral neck fracture. We present an experimental study which asses and compare biomechanical and clinical status through period before and after hip fracture and implantation of bipolar partial hip endoprosthesis. This study encompassed 75 patients who suffered from an acute medial femoral neck fracture and were treated with the implantation of a bipolar partial hip endoprosthesis. Their biomechanical status (stress distribution on the hip joint weight bearing area) and clinical status (Harris Hip Score) were estimated for the time prior to the injury and assessed at the follow-up examination that was, on average, carried out 40 months after the operation. Despite ageing, the observed Harris Hip Score at the follow-up examination was higher than that estimated prior to the injury (77.9 > 69.6; p = 0.006). Similarly, the hip stress distribution was reduced (2.7 MPa < 2.3 MPa; p = 0.001). While this reduction can be attributed to a loss of weight due to late ageing, the principal improvement came from the operative treatment and corresponding restoration of the biomechanical properties of the hip joint. The implantation of a bipolar partial hip endoprosthesis for patients with displaced medial femoral neck fractures improves the biomechanical and clinical features of the hip, what should have on mind during making decision about treatment.     

Bone density and risk of hip fracture in men and women: cross sectional analysis.

OBJECTIVE: To determine the relative contribution of decline in bone density to the increase in risk of hip fracture with age in men and women. DESIGN: Incidence data of hip fracture from the general population were combined with the bone density distribution in a sample from the same population and with a risk estimate of low bone density known from literature. SETTING: The Netherlands. SUBJECTS: All people with a hospital admission for a hip fracture in 1993, and bone density measured in a sample of 581.4 men and women aged 55 years and over in a district of Rotterdam. MAIN OUTCOME MEASURE: One year cumulative risk of hip fracture by age, sex, and bone density measured at the femoral neck. RESULTS: A quarter of all hip fractures occurred in men. Men reached the same incidence as women at five years older. Controlled for age, the risk of hip fracture by bone density was similar in men and women. The risk of hip fracture increased 13-fold from age 60 to 80; decrease in bone density associated with age contributed 1.9 (95% confidence interval 1.5 to 2.4) in women and 1.6 (1.3 to 1.8) in men. CONCLUSIONS: The risk of hip fracture by age and bone density is similar in men and women. The decrease in bone density associated with age makes a limited contribution to the exponential increase of the risk of hip fracture with age.     

Bone marrow levels of 25 hydroxy vitamin D are not depressed in cases of hip fracture compared with controls

There is little information on tissue as distinct from plasma levels of vitamin D metabolites in cases of hip fracture compared with controls. Femoral neck fractures in the elderly are associated with increased cortical remodelling and endosteal resorption, leading to regional increases in porosity and reduced cortical thickness. Vitamin D metabolites play a central role in the maintenance of normal serum calcium levels and may, through interactions with parathyroid hormone, exert an important influence on bone structure. To investigate whether hip fracture might be associated with tissue vitamin D deficiency, we have measured by radioimmunoassay the levels of 25 hydroxy vitamin D (25 (OH)D) in bone marrow samples extracted from the proximal femurs of 16 female subjects who had suffered fracture (mean age = 82.1 years, standard error (se) 1.9) and nine sex matched post mortem controls (mean age = 83.8 years, se 2.5). Twenty five (OH)D concentrations were significantly greater in the fracture cases (median = 3.7, IQR = 2.5–3.9 ng/g) than in the control group (median = 1.5, IQR = 0.9–2.3 ng/g; P = 0.0007, non‐parametric Wilcoxon/Kruskal–Wallis test). It was suggested in the 1970s that bone loss and hip fracture risk in the UK were driven by vitamin D deficiency. Our results suggest that the alterations in femoral neck bone microstructure and remodelling in hip fracture cannot be assigned to the single cause of relative deficiency of vitamin D. Vitamin D deficiency or insufficiency may nevertheless increase remodelling and loss of bone tissue and contribute causally to a minority of hip fractures. Copyright © 2013 John Wiley & Sons, Ltd.     

Community water fluoridation, bone mineral density, and fractures: prospective study of effects in older women

ObjectiveTo determine whether fluoridation influences bone mineral density and fractures in older women.DesignMulticentre prospective study on risk factors for osteoporosis and fractures.SettingFour community based centres in the United States.Participants9704 ambulatory women without bilateral hip replacements enrolled during 1986-8; 7129 provided information on exposure to fluoride.ResultsWomen were classified as exposed or not exposed or having unknown exposure to fluoride for each year from 1950 to 1994. Outcomes were compared in women with continuous exposure to fluoridated water for the past 20 years (n=3218) and women with no exposure during the past 20 years (n=2563). In women with continuous exposure mean bone mineral density was 2.6% higher at the femoral neck (0.017 g/cm², P<0.001), 2.5% higher at the lumbar spine (0.022 g/cm², P<0.001), and 1.9% lower at the distal radius (0.007 g/cm², P=0.002). In women with continuous exposure the multivariable adjusted risk of hip fracture was slightly reduced (risk ratio 0.69, 95% confidence interval 0.50 to 0.96, P=0.028) as was the risk of vertebral fracture (0.73, 0.55 to 0.97, P=0.033). There was a non-significant trend toward an increased risk of wrist fracture (1.32, 1.00 to 1.71, P=0.051) and no difference in risk of humerus fracture (0.85, 0.58 to 1.23, P=0.378).ConclusionsLong term exposure to fluoridated drinking water does not increase the risk of fracture.     

Influence of instability and muscular weakness in ethiopathogenesis of hip fractures

The aim of our study was to, in accordance with the presented theoretical presumptions, analyze the possible reasons for hip fractures of the older population in the north-eastern part of Croatia. A group of 2,696 persons (1,936 women and 760 men) with hip fractures has been analyzed during a 12 year period (from 1993. until 2005. year) in the Clinical Hospital Osijek. The date of admittance, age, gender and fracture location were recorded. In men, the incidence of total hip fracture number on the left side was greater 23.5% (p<0.01) compared to the right side, while in women this difference does not exist. Men have a greater incidence of trochanteric fractures than fractures of femoral neck on both sides, while in women this difference could be shown on the right side only. In women, a 30.5% (p<0.001) higher fracture incidence occurred in the winter compared to the summer. It has been concluded that in men the impaired neuromuscular function on the left body side caused the greater incidence of falls on this side. The more frequent multifragmental fractures of the trochanteric massive in men indicate the possible role of preserved pelvitrochanteric muscle tension in fracture characterization. Increased incidence of falls and fractures in the older female population can be interpreted with a more pronounced weakness of pelvitrochanteric muscles and consequent walking instability. Furthermore, a smaller incidence of hip fractures was noticed in the summer compared with winter. This is explained by a reduced exhaustion of pelvic muscles in summer (primarily pelvitrochanteric) and decrease in fall frequency.     

Pelvis and femur geometry: Relationships with impact characteristics during sideways falls on the hip

While metrics of pelvis and femur geometry have been demonstrated to influence hip fracture risk, attempts at linking geometry to underlying mechanisms have focused on fracture strength. We investigated the potential effects of femur and pelvis geometry on applied loads during lateral falls on the hip. Fifteen female volunteers underwent DXA imaging to characterize two pelvis and six femur geometric features. Additionally, participants completed low-energy sideways falls on the hip; peak impact force and pressure, contact area, and moment of force applied to the proximal femur were extracted. No geometric feature was significantly associated with peak impact force. Peak moment of force was significantly associated with femur moment arm (p = 0.005). Peak pressure was positively correlated with pelvis width and femur moment arm (p < 0.05), while contact area was negatively correlated with metrics of pelvis width and femur neck length (p < 0.05). This is the first study to link experimental measures of impact loads during sideways falls with image-based skeletal geometry from human volunteers. The results suggest that while skeletal geometry has limited effects on overall peak impact force during sideways falls, it does influence how impact loads are distributed at the skin surface, in addition to the bending moment applied to the proximal femur. These findings have implications for the design of protective interventions (e.g. wearable hip protectors), and for models of fall-related lateral impacts that could incorporate the relationships between skeletal geometry, external load magnitude/distribution, and tissue-level femur loads.     

A biomechanical comparison of composite femurs and cadaver femurs used in experiments on operated hip fractures

Fourth generation composite femurs (4GCFs, models #3406 and #3403) simulate femurs of males <80 years with good bone quality. Since most hip fractures occur in old women with fragile bones, concern is raised regarding the use of standard 4GCFs in biomechanical experiments. In this study the stability of hip fracture fixations in 4GCFs was compared to human cadaver femurs (HCFs) selected to represent patients with hip fractures.Ten 4GCFs (Sawbones, Pacific Research Laboratories, Inc., Vashon, WA, USA) were compared to 24 HCFs from seven females and five males >60 years. Proximal femur anthropometric measurements were noted. Strain gauge rosettes were attached and femurs were mounted in a hip simulator applying a combined subject-specific axial load and torque. Baseline measurements of resistance to deformation were recorded. Standardized femoral neck fractures were surgically stabilized before the constructs were subjected to 20,000 load-cycles. An optical motion tracking system measured relative movements.Median (95% CI) head fragment migration was 0.8 mm (0.4 to 1.1) in the 4GCF group versus 2.2 mm (1.5 to 4.6) in the cadaver group (p=0.001). This difference in fracture stability could not be explained by observed differences in femoral anthropometry or potential overloading of 4GCFs. 4GCFs failed with fracture-patterns different from those observed in cadavers.To conclude, standard 4GCFs provide unrealistically stable bone-implant constructs and fail with fractures not observed in cadavers. Until a validated osteopenic or osteoporotic composite femur model is provided, standard 4GCFs should only be used when representing the biomechanical properties of young healthy femurs.     

Laser-Supported Dual Energy X-Ray Absorptiometry (DXL) Compared to Conventional Absorptiometry (DXA) and to FRAX as Tools for Fracture Risk Assessments

Dual X-ray and Laser (DXL) adds a measure of the external thickness of the heel, measured by laser, to a conventional measurement of bone mineral density (BMD) of the calcaneus, using Dual energy X-ray Absorptiometry (DXA). The addition of heel thickness aims at a better separation of fatty tissue from bone than the standard method of DXA, which may mistake fatty tissue for bone and vice versa. The primary aim of this study was to evaluate whether DXL of the calcaneus can be used to assess the 10-year risk of fractures. Secondary aims were to compare the predictive ability of DXL with the two most established methods, Dual energy X-ray Absorptiometry (DXA) of the hip and spine and the WHO fracture risk assessment tool, FRAX. In 1999 a cohort of 388 elderly Swedish women (mean age 73.2 years) was examined with all three methods. Prospective fracture data was collected in 2010 from health care registers. One SD decrease in BMD of the heel resulted in an age-adjusted Hazard Ratio (HR) of 1.47 for a hip fracture (95% CI 1.09–1.98). Harrell’s C is the Cox regression counterpart of the Area Under Curve (AUC) of the Receiver Operating Characteristic (ROC) as a measure of predictive accuracy. Harrell’s C for BMD of the calcaneus was 0.65 for prediction of hip fractures. These results were not significantly different from those for BMD of the femoral neck or for FRAX. The HR for a hip fracture, for one SD decrease in BMD at the femoral neck, was 1.72 (95% CI 1.21–2.44. Harrell’s C was 0.67 for BMD at the femoral neck and 0.59 for FRAX. We conclude that DXL of the calcaneus could be a useful tool for fracture risk assessments.     

Bone related health status in adolescent cyclists

Purpose

To describe bone status and analyse bone mass in adolescent cyclists.

Methods

Male road cyclists (n = 22) who had been training for a minimum of 2 years and a maximum of 7 years with a volume of 10 h/w, were compared to age-matched controls (n = 22) involved in recreational sports activities. Subjects were divided in 2 groups based on age: adolescents under 17 yrs (cyclists, n = 11; controls, n = 13) and over 17 yrs (cyclists, n = 11; controls, n = 9). Peak oxygen uptake (VO₂max) was measured on a cycloergometer. Whole body, lumbar spine, and hip bone mineral content (BMC), density (BMD) and bone area were assessed using dual x-ray absorptiometry (DXA). Volumetric BMD (vBMD) and bone mineral apparent density (BMAD) were also estimated.

Results

The BMC of cyclists was lower for the whole body, pelvis, femoral neck and legs; BMD for the pelvis, hip, legs and whole body and legs bone area was lower but higher in the hip area (all, P≤0.05) after adjusting by lean mass and height. The BMC of young cyclists was 10% lower in the leg and 8% higher in the hip area than young controls (P≤0.05). The BMC of cyclists over 17 yrs was 26.5%, 15.8% and 14.4% lower BMC at the pelvis, femoral neck and legs respectively while the BMD was 8.9% to 24.5% lower for the whole body, pelvis, total hip, trochanter, intertrochanter, femoral neck and legs and 17.1% lower the vBMD at the femoral neck (all P≤0.05). Grouped by age interaction was found in both pelvis and hip BMC and BMD and in femoral neck vBMD (all P≤0.05).

Conclusion

Cycling performed throughout adolescence may negatively affect bone health, then compromising the acquisition of peak bone mass.     

Bone Analysis Using Trabecular Bone Score and Dual-Energy X-Ray Absorptiometry-Based 3-Dimensional Modeling in Postmenopausal Women With Primary Hyperparathyroidism

ObjectivePredominance of bone loss in cortical sites with relative preservation of trabecular bone, even in postmenopausal women, has been described in primary hyperparathyroidism (PHPT). The aim of this study was to evaluate bone microarchitectural differences using dual-energy x-ray absorptiometry (DXA), trabecular bone score (TBS), and DXA-based 3-dimensional (3D) modeling (3D-DXA) between postmenopausal women diagnosed with PHPT (PM-PHPT) and healthy postmenopausal controls.MethodsThis retrospective study included 44 women with PM-PHPT (9 of whom had fractures) and 48 healthy women matched by age, body mass index, and years since menopause treated at Hospital Universitario Fundación Jiménez Díaz between 2008 and 2017. The bone mineral density (BMD) of the lumbar spine (LS), femoral neck, total hip (TH), and 1/3 radius was assessed using DXA, and trabecular volumetric BMD (vBMD), cortical vBMD, integral vBMD, cortical thickness, and cortical surface BMD at TH were assessed using a 3D-DXA software and TBS at LS.ResultsThe mean adjusted BMD values at LS, the femoral neck, and TH; TBS at LS; and TH 3D-DXA parameters (trabecular vBMD, integral vBMD, cortical thickness, and cortical surface BMD) were significantly reduced in women with PM-PHPT compared with those in the controls. However, differences in mean cortical vBMD were not statistically significant (P = .078). There were no significant differences in mean BMD, TBS, or the 3D-DXA parameters between patients with fractures and those without fractures. The 25-hydroxyvitamin D level appeared to be associated with TBS but not with DXA and 3D-DXA measurements.ConclusionPM-PHPT has significant involvement of the trabecular and cortical compartments of the bone, as determined by DXA, TBS, and 3D-DXA.     

全髋和半髋置换治疗老年股骨颈骨折的临床对比分析

目的:探讨全髋和半髋关节置换术治疗老年股骨颈骨折的临床疗效。方法:选择本院收治的70例老年股骨颈骨折患者,采用随机数字表法将其分为观察组和对照组各35例,观察组给予全髋关节置换术,对照组予以半髋关节置换术,对比两组所用手术时间、术中出血量、术后Harris评分及髋关节功能、术后并发症、疼痛率及翻修率。结果:观察组手术时间为(113.6±19.3)min,术中出血量为(432.1±32.7)ml,均显著高于对照组的(73.1±10.2)min、(201.3±30.1)m L,两组比较差异均有统计学意义(均P0.05);观察组髋关节功能总优良率、Harris评分分别为91.43%,(91.13±5.09)分,显著优于对照组的77.14%、(80.15±4.71)分,两组比较差异均有统计学意义(均P0.05);观察组不良反应发生率及翻修率分别为20.00%、0.00%,低于对照组的22.85%、5.71%,但差异均无统计学意义(均P0.05);观察组疼痛率为5.71%,显著低于对照组的25.71%,两组比较差异有统计学意义(P0.05)。结论:两种术式对股骨颈骨折的老年患者均能起到有效的治疗,均有各自的优缺点,对疼痛较为敏感和活动较多的老年患者而言,宜采用全髋关节置换术。     

Impact loading history modulates hip fracture load and location: A finite element simulation study of the proximal femur in female athletes

Sideways falls impose high stress on the thin superolateral cortical bone of the femoral neck, the region regarded as a fracture-prone region of the hip. Exercise training is a natural mode of mechanical loading to make bone more robust. Exercise-induced adaptation of cortical bone along the femoral neck has been previously demonstrated. However, it is unknown whether this adaption modulates hip fracture behavior. The purpose of this study was to investigate the influence of specific exercise loading history on fall-induced hip fracture behavior by estimating fracture load and location with proximal femur finite element (FE) models created from magnetic resonance images (MRI) of 111 women with distinct exercise histories: 91 athletes (aged 24.7 ± 6.1 years, >8 years competitive career) and 20 women as controls (aged 23.7 ± 3.8 years). The athletes were divided into five groups based on typical loading patterns of their sports: high-impact (H-I: 9 triple-jumpers and 10 high jumpers), odd-impact (O-I: 9 soccer and 10 squash players), high-magnitude (H-M: 17 power-lifters), repetitive-impact (R-I: 18 endurance runners), and repetitive non-impact (R-NI: 18 swimmers). Compared to the controls, the H-I, O-I, and R-I groups had significantly higher (11–26%, p < 0.05) fracture loads. Also, the fracture location in the H-I and O-I groups was significantly more proximal (7–10%) compared to the controls. These results suggest that an exercise loading history of high impacts, impacts from unusual directions, or repetitive impacts increases the fracture load and may lower the risk of fall-induced hip fracture.     

Relationship between eccentric hip torque and lower-limb kinematics: gender differences

The purposes of this study were to compare lower-limb kinematics between genders, and determine the relationships among eccentric hip abductor and lateral rotator torques and lower-limb kinematics. The movements of the pelvis, femur, and knee were calculated for 16 women and 16 men during the single-leg squat. Eccentric hip abductor and lateral rotator torques were measured using an isokinetic dynamometer. The results showed that women had greater contralateral pelvic depression, femur adduction, and knee abduction than men. The eccentric hip abductor and lateral rotator torques were correlated with coronal plane femur and knee movements in the overall sample. When the genders were analyzed separately, it was observed that women with greater eccentric hip abductor torque exhibited less femur adduction and femur medial rotation, and greater knee adduction excursion. No significant relationship was observed between the isokinetic and kinematic variables in the male group. The differences between the genders help to explain the greater rate of knee disorders observed in women. Moreover, the eccentric hip abduction action seemed to be more important in women to control the lower-limb movements.     

Milk consumption and bone mineral density in middle aged and elderly women.

OBJECTIVES--To study the effects of historical milk consumption on current bone mineral density at the hip and spine. DESIGN--Cross sectional study. SUBJECTS--284 community based women aged 44-74 years recruited from four general practice age-sex registers in Cambridge. Subjects categorised their average milk consumption up to age 25, from age 25-44, and from age 44 to the present time as > or = 1 glass/day, < 1 glass/day but > 1 glass/week, or < 1 glass/week. MAIN OUTCOME MEASURES--Bone mineral density at the hip and spine measured by dual energy x ray absorptiometry. RESULTS--Data on milk consumption up to age 25 years were available for 252 women. There was a consistent upward trend in bone mineral density at all sites with increasing historical milk consumption (total hip, femoral neck, trochanter, intertrochanter, P < 0.05; Ward''s triangle, P = 0.005). Adjustment for age and body size did not alter these trends. Milk consumption up to age 25 was a significant independent predictor of bone mineral density at all sites in multiple linear regression analyses controlling for age, body mass index, menopausal status, smoking, ever use of hormone replacement therapy or oral contraceptives, physical activity, and alcohol intake. The effects of milk consumption from age 25-44 and from age 44 to the present were similar in direction though not statistically significant. CONCLUSION--Frequent milk consumption before age 25 favourably influences hip bone mass in middle aged and older women.     

During sideways falls proximal femur fractures initiate in the superolateral cortex: Evidence from high-speed video of simulated fractures

Results of recent imaging studies and theoretical models suggest that the superior femoral neck is a location of local weakness due to an age-related thinning of the cortex, and thus the site of hip fracture initiation. The purpose of this study was to experimentally determine the spatial and temporal characteristics of the macroscopic failure process during a simulated hip fracture that would occur as a result of a sideways fall. Twelve fresh frozen human cadaveric femora were used in this study. The femora were fractured in an apparatus designed to simulate a fall on the greater trochanter. Image sequences of the surface events related to the fractures were captured using two high-speed video cameras at 9111 Hz. The videos were analyzed with respect to time and load to determine the location and sequence of these events occurring in the proximal femur. The mean failure load was 4032 N (SD 370 N). The first surface events were identified in the superior femoral neck in eleven of the twelve specimens. Nine of these specimens fractured in a clear two-step process that initiated with a failure in the superior femoral neck, followed by a failure in the inferior femoral neck. This cadaveric model of hip fracture empirically confirms hypotheses that suggested that hip fractures initiate with a failure in the superior femoral neck where stresses are primarily compressive during a sideways fall impact, followed by a failure in the inferior neck where stresses are primarily tensile. Our results confirm the superolateral neck of the femur as an important region of interest for future hip fracture screening, prevention and treatment research.     

人工髋关节置换术治疗高龄患者股骨粗隆间骨折的临床疗效研究

目的:探究人工髋关节置换术治疗高龄患者股骨粗隆间骨折的临床疗效。方法:选择40例高龄股骨粗隆间骨折患者并将其随机分为两组,观察组给予人工髋关节置换术治疗,对照组经股骨近端髓内钉内固定术治疗。观察比较两组L2-4椎体骨密度、疼痛程度、髋关节功能恢复情况及Harris评分。结果:治疗后,两组L2-4椎体骨密度均显著高于治疗前(P0.05),且观察组显著高于对照组(P0.05);观察组疼痛比例较治疗前明显降低(P0.05),且显著低于对照组(P0.05);观察组髋关节恢复优良率为95.0%,显著高于对照组(70.0%,P0.05);两组Harris评分均显著高于治疗前(P0.05),且观察组显著高于对照组(P0.05)。结论:采用人工髋关节置换术治疗高龄股骨粗隆间骨折的疗效明显优于经股骨近端髓内钉内固定术治疗,其可有效促进髋关节功能恢复,减轻患者疼痛。     

Relevance of osteoporosis in women with fracture of the femoral neck.

A prospective study of fractures of the femoral neck was conducted over 12 months in order to ascertain the relevance of generalised osteoporosis as determined by metacarpal morphometry. A series of some 200 women sustaining a fracture of the femoral neck after minor trauma had bone mass measurements similar to those of a control population of normal women, and 16% were not osteoporotic. A history of previous fractures was documented in one third of the women, but this was unrelated to the presence or severity of osteoporosis, although over half of the fractures had occurred within the previous four years. Trochanteric fractures were seen more commonly in severely osteoporotic women (p less than 0.005), whereas cervical fractures predominated in those who were not osteoporotic. These findings support the hypothesis that postural instability is the major determinant for femoral neck fracture and that generalised osteoporosis, rather than being a prerequisite for fracture, merely determines the type of fracture sustained.     

The Association between Metabolic Syndrome,Bone Mineral Density,Hip Bone Geometry and Fracture Risk: The Rotterdam Study

The association between metabolic syndrome (MS) and bone health remains unclear. We aimed to study the association between MS and hip bone geometry (HBG), femoral neck bone mineral density (FN-BMD), and the risk of osteoporosis and incident fractures. Data of 2040 women and 1510 men participants in the third visit (1997–1999) of the Rotterdam Study (RSI-3), a prospective population based cohort, were available (mean follow-up 6.7 years). MS was defined according to the recent harmonized definition. HBG parameters were measured at the third round visit whereas FN-BMD was assessed at the third round and 5 years later. Incident fractures were identified from medical registry data. After correcting for age, body mass index (BMI), lifestyle factors and medication use, individuals with MS had lower bone width (β = -0.054, P = 0.003), lower cortical buckling ratio (β = -0.81, P = 0.003) and lower odds of having osteoporosis (odds ratio =0.56, P = 0.007) in women but not in men. Similarly, MS was associated with higher FN-BMD only in women (β = 0.028, P=0.001). In the analyses of MS components, the glucose component (unrelated to diabetes status) was positively associated with FN-BMD in both genders (β = 0.016, P = 0.01 for women and β = 0.022, P = 0.004 for men). In men, waist circumference was inversely associated with FN-BMD (β = -0.03, P = 0.004). No association was observed with fracture risk in either sex. In conclusion, women with MS had higher FN-BMD independent of BMI. The glucose component of MS was associated with high FN-BMD in both genders, highlighting the need to preserve glycemic control to prevent skeletal complications.     

Raloxifene: results from the MORE study

Raloxifene is the first Selective Estrogen Receptor Modulator (SERM) approved for the prevention and treatment of osteoporosis in postmenopausal women. Acting as an estrogen agonist in the skeleton and on lipid metabolism, raloxifene maintains bone mineral density (BMD) and prevents new vertebral fractures while improving the lipid profile in postmenopausal women. In an osteoporosis prevention study, 601 women without osteoporosis, aged 45 to 60 years, were assigned to receive a placebo or raloxifene 30, 60, or 150 mg/day. All women received calcium (400 to 600 mg/day). Raloxifene 60 mg increased BMD by 2.4% at both the lumbar spine and hip compared with the placebo at 36 months. More importantly, however, raloxifene significantly reduced the risk of new vertebral fractures in Multiple Outcomes of Raloxifene Evaluation (MORE), a placebo-controlled, double-blind randomized trial of 7705 postmenopausal women with osteoporosis. The women, with a mean age of 66.5 years, and with hip or spine T-score <-2.5 and/or prevalent vertebral fractures, were assigned to receive either a placebo or 60 mg or 120 mg of raloxifene. All women were provided supplemental calcium (500 mg/day) and vitamin D (400 IU/day). After 36 months, raloxifene 60 mg/day and 120 mg/day, reduced the risk of new vertebral fractures by 55% (RR 0.45, 95% CI 0.3, 0.7; p<0.001), and 40% (RR 0.60, CI 0.4, 0.9) in women without prevalent baseline fractures, respectively; and by 31% (RR 0.7, 95% CI 0.6, 0.9; p<0.001), and 49% (RR 0.5, CI 0.4, 0.6) in women with prevalent baseline fractures compared with the placebo. There was no difference in the proportion of women reporting non-traumatic, non - spine fractures among women receiving raloxifene compared to the placebo-treated women. Compared with placebo, BMD increased after 36 months by 2.1 and 2.6% at the femoral neck and spine, respectively, in the 60mg raloxifene group, and by 2.4 and 2.7% at the femoral neck and spine, respectively, in the 120mg raloxifene group. By 40 months of follow-up, there was a higher rate of deep venous thrombosis (38 cases) and pulmonary embolus (17 cases) in the combined raloxifene groups than in the placebo group (5 and 3 cases,), with a relative risk of 3.1, (CI 1.5-6.2). By 40 months, 54 women had a confirmed diagnosis of breast cancer with a relative risk compared to placebo of 0.35, (CI, 0.21-0.58). Raloxifene therapy for 3 years maintains BMD in healthy postmenopausal women and significantly reduces the risk of new vertebral fractures by about half in postmenopausal women with osteoporosis. Raloxifene also reduces the risk of breast cancer by 65% in postmenopausal women with osteoporosis thus providing a new choice for addressing postmenopausal health concerns.