Bone density measurements

Early diagnosis of osteoporosis is difficult. Bone density measurements, however, are helpful in screening patients at risk. Technology now provides means of measuring densities of both peripheral and central bones. The most practical method is dual X-ray densitometry, which is of good sensitivity and accuracy. Single photon absorptiometry on peripheral bones can be used to screen populations at risk. Computed tomography is also useful but the radiation dose is relatively high. In dual X-ray densitometry, calibration methods and comparisons with reference values are farily reliable. The best sites for measurements are the lumbar spine and proximal femur, in which osteoporotic fractures are common. In general, however, one measurement is not enough. Biological variation is great. Repeated measurements will allow estimation of the rate of bone loss. Precise location of a previous site is sometimes difficult on reexamination and extraskeletal calcifications can be sources of error. Bone densitometry in connection with the prevention and treatment of osteoporosis is fairly easily performed with a single patient. Knowledge about the correlation between bone density and fracture risk is not yet adequate. The results of measurement of bone mineral density relate only to mineral content, not bone quality, i.e., differential diagnosis of osteoporosis and osteomalacia is not possible.     

Discriminative Capacity of Calcaneal Quantitative Ultrasound and of Osteoporosis and Fracture Risk Factors in Postmenopausal Women with Osteoporotic Fractures

Bone fragility fractures constitute the principal complication of osteoporosis. The identification of individuals at high risk of sustaining osteoporotic fractures is important for implementing preventive measures. The purpose of this study is to analyze the discriminative capacity of a series of osteoporosis and fracture risk factors, and of calcaneal quantitative ultrasound (QUS), in a population of postmenopausal women with a history of osteoporotic fracture. A cross-sectional analysis was made of a cohort of 5195 women aged 65 or older (mean±SD: 72.3±5.4 years) seen in 58 primary care centers in Spain. A total of 1042 women (20.1%) presented with a history of osteoporotic fracture. Most fractures (93%) were non-vertebral. Age-adjusted odds ratios corresponding to each decrease in one standard deviation of the different QUS parameters ranged from 1.47 to 1.55 (P < 0.001) for fractures. The age-adjusted multivariate analysis yielded the following risk factors independently associated with a history of osteoporotic fracture: number of fertile years, a family history of fracture, falls in the previous year, a history of chronic obstructive airway disease, the use of antiarrhythmic drugs, and a low value for any of the QUS parameters. The area under the receiver operating characteristic curve of the best model was 0.656. In summary, a series of easily assessable osteoporotic fracture risk factors has been identified. QUS was shown to discriminate between women with and without a history of fracture, and constitutes a useful tool for assessing fracture risk. Various of the vertebral and hip fracture risk factors frequently cited in North American and British populations showed no discriminative capacity in our series—thus suggesting that such factors may not be fully applicable to our population and/or to the predominant type of fractures included in the present study. For a complete list of ECOSAP investigators, see Appendix ECOSAP, Ecografia Ósea in Atención Primaria     

Total body and regional bone mineral by dual-photon absorptiometry in metabolic bone disease

Summary Dual-photon absorptiometry (¹⁵³Gd) was used to measure bone mineral of the total body and major anatomical areas. Patients with osteoporosis (♂=11, ♀=18) and with renal osteodystrophy (n=17) were significantly below (20%) normal females (n=72) and males (n=13) at most sites. In the osteoporotic patients, but not the renal patients, there was preferential osteopenia of the spine. Bone loss in all anatomical areas became evident after the menopause with an annual loss rate of about 0.7%.     

Update on the use of distal radial bone density measurements in prediction of hip and Colles' fracture risk

A controversy has developed around the question as to whether bone density values from the distal radius can be used to accurately predict risk of future fractures. To address this question, two separate studies were undertaken: (a) Bone density was measured in 460 healthy ambulatory women living in retirement centers in the state of North Carolina; 83% of these women were followed for up to 60 months for occurrence of minimal trauma hip and wrist fractures. Thirty-one minimal trauma fractures were reported in our study population, representing 8% of those followed. The fracture incidence density rate showed a close inverse relationship with incremental changes in bone density at the distal site. Twenty-eight of the 31 fractures were reported in women with bone density values below the 325-mg/cm2 "at risk" value. (b) Bone density values of the distal radius and the lumbar spine from 360 women (aged 18-85 years) from the Chapel Hill area were used to analyze the error in predicting individual spinal density from the distal radial density. Although the overall correlation was high (r = 0.67) and the confidence intervals were narrow, the prediction intervals were quite wide. Thus, prediction of an individual value of spine density from the distal radius density would result in a value with a range too wide to be clinically useful. We conclude that single-photon absorptiometry appears to be a useful tool for screening normal populations of asymptomatic women for prediction of hip or Colles' fracture risk even though it has limited usefulness in prediction of spinal fracture risk or individual values for spinal density.     

Ultrasound,densitometry, and extraskeletal appendicular fracture risk factors: A cross-sectional report on The Saunders County Bone Quality Study

The Saunders County Bone Quality Study was designed to determine the feasibility of ultrasonic bone measurement, at the patella, as a predictor of low-trauma fractures in a runal population-based study. At the first visit of this 4-year longitudinal study, anthropometric and clinical measurements and medical, surgical, and fracture histories were obtained for the 1428 participants (899 women and 529 men). Explored risk factors for low-trauma fractures included age, sex, calcium intake, alcohol and caffeine ingestion, tobacco use, body mass and grip strength, age of menopause, estrogen replacement therapy, propensity to fall, distal radius and ulna bone mineral content, and bone density. Forward multivariate logistic regression analysis showed that lower ultrasound values are more consistently associated with reported low-trauma appendicular fractures than the commonly reported forearm absorptiometry measures of radius mineral content and density. When ultrasound, age, and the extra skeletal risk factors were included in an additional multivariate model, only age and ultrasound were significantly associated with appendicular fracture history in women (P=0.0003), whereas only ultrasound was associated in the men (P=0.001). We conclude that ultrasound is a better measure of association with reported low-trauma fractures than the commonly reported forearm SPA measures. Even after adjustment for many of the extra skeletal risk factors, low AVU is highly associated with low-trauma fracture status for both women and men.     

Peak bone mass, bone loss and risk of fracture

Both peak bone mass and bone loss contribute to subsequent fracture risk. Other variables such as architectural abnormalities, microdamage, geometric properties, and trauma probably contribute as well. Until the contribution of these other potentially important risk factors can be quantified, it will be difficult to determine precisely the relative importance of peak bone mass and subsequent bone loss in the etiology of fractures.     

Volumetric bone density of the lumbar spine is related to fat mass but not lean mass in normal postmenopausal women

We have previously found that fat mass but not lean body mass is related to bone mineral density (BMD) in women. In these and most other studies of the dependence of BMD on body composition, areal rather than volumetric bone density was measured. It is possible that the dependence of this variable on body size introduced a scale artifact that contributed to the previous findings. The present study addresses this issue by measuring thevolumetric density of the third lumbar vertebra from simultaneous anteroposterior (AP) and lateral scans using dual-energy X-ray absorptiometry in 119 normal postmenopausal women. Whole body fat and lean body mass were also measured using this technique. In the AP projection, BMD was similarly related to body weight and to fat mass (r=0.44,p<0.0001 for both) but not to lean body mass (r=0.17, NS). BMD in the lateral projection was less closely related to body composition than was AP BMD, but the greater impact of fat (r=0.25,p<0.01) than lean body mass (r=0.09, NS) was still evident. When AP or lateral BMDs were divided by height, arm span or the square root of the scan area to produce an index with the dimensions of volumetric density, the dependence of BMD on body weight and fat mass were not affected but the relationship to lean body mass was eliminated (–0.02<r<0.09). Similarly, the volumetric density of the third lumbar vertebra was related to fat mass (r=0.21,p=0.02) but not to lean body mass (r=0.01). It is concluded that BMD is related to fat mass and that previously reported associations between lean body mass and BMD are probably contributed to by a scaling factor arising from failure to measure volumetric bone density.     

伴有跟骰关节损伤的跟骨骨折

目的探讨伴有跟骰关节损伤的跟骨骨折的损伤机制、特点和治疗方法。方法1997年2月～2001年4月．71例90足跟骨骨折伴跟骰关节损伤患者，男46例61足．女25例29足：年龄18～67岁，平均38．7岁；左足47足．右足43足。高处坠落伤84足，车祸伤5足，楼梯踏空伤1足，其中12倒合并其它损伤，包括8例胸腰推骨折、1例对侧陉骨pilon骨折、2例股骨干骨折、1例股骨干及肋骨骨折和创伤性体克。根据所摄X线片、CT及跟骰关节面损伤的特点将跟骰关节损伤归纳为四种类型：Ⅰ型46足，占51.1％(46/90)；Ⅱ型26足．占28.9％(26／90)；Ⅲ型11足．占12．2％(11／90)；Ⅳ型7足．占7．8％(7/90)，结果61例78足获得随访，随访时间12～32个月，平均l8.4个月。接Maryland足部评分系镜评价术后功能：优49足．良25足，可4足；总忧良率为94.9％。其中Ⅰ型优良率为100％（41／41)，Ⅱ型为95．7％(22/23)．Ⅲ型为88．9％(8／9)．Ⅳ型为60％(3/5)，结论跟骰关节损伤与跟骨骨折的严重程度有关．在治疗跟骨骨折时应重视跟骰关节的损伤情况及手术固定效果．跟骰关节的损伤程度直接影响跟骨骨折的治疗效果。     

单能与双能X线吸收法测量骨密度的比较

应用单能Ｘ线测量（ＳＸＡ）及双能Ｘ线测量（ＤＥＸＡ）法测量北京地区正常妇女骨密度，对两种方法进行比较，以选择反映骨丢失敏感的部位。共测量３００名，年龄为２０～７９岁，每岁５名，测量部位分别为ＳＸＡ法的非优势前臂远端（８ｍｍ－Ｄ）、１／４远端（１／４－Ｄ）、超远端（Ｕｌｔｒａ－Ｄ），ＤＥＸＡ法的腰椎正位（Ｌ２－４）、右股骨颈（Ｎｅｃｋ）、Ｗａｒｄ＇ｓ三角（Ｗａｒｄ）及粗隆区（Ｔｒｏｃｈ），两种方法各有１０名妇女进行了仪器重复性检验。Ｎｅｃｋ、Ｗａｒｄ骨密度峰值分布在２０～２９岁，Ｕｌｔｒａ－Ｄ、Ｌ２－４ＢＭＤ分布在３０～３９岁，８ｍｍ－Ｄ、１／４－Ｄ、Ｔｒｏｃｈ分布于４０～４９岁年龄组。所有部位ＢＭＤ在峰值后随年龄增长逐渐降低，８ｍｍ－Ｄ年下降率最高（１．１６％）。两种方法测得７个部位ＢＭＤ值之间均有显著相关。与绝经前相比，绝经后妇女各部位ＢＭＤ值下降迅速，尤以绝经后１１～１５年内显著，其中Ｗａｒｄ三角下降率最高为４２．９％。     

Ultrasound velocity of the tibia in normal german women and hip fracture patients

One of the latest developments in quantitative ultrasound (QUS) is the measurement of the speed of sound (SOS) of cortical bone of the midtibia. To determine the diagnostic validity of this method we measured 150 healthy women aged 22–94 years. Additionally, we report on first results of patients with hip fracture. Precisionin vivo of the tibial QUS expressed as the percentage coefficient of variation (CV) was 0.39% for the first day and 0.45% after repositioning the second day (mean CV=0.42%). No significant dependency of tibial SOS was found with weight, height, and body mass index in pre- and postmenopausal women. There was a significant decline of SOS with age in postmenopausal women (SOS=4225–5.3 age, r=−0.46,P<0.001), whereas premenopausal women showed no decline (SOS=3906+1.3 age, r=0.13, ns) Mean SOS values of premenopausal women were significantly higher than those of postmenopausal women (3960±78.7 m/second and 3898±120 m/second, respectively,P<0.001). Postmenopausal women on estrogen substitution had significantly higher mean tibial SOS values than age-comparable postmenopausal women without estrogen substitution (3980±99 m/second and 3869±100 m/second, respectively,P<0.001). Significant difference between age-matched healthy women, n=11, and hip fracture patients, n=13, expressed as z-score of −1.4 SD was found. In conclusion, tibial QUS declines with age and detects higher values in premenopausal women and postmenopausal women on estrogen substitution and lower values in hip fracture patients. Further prospective studies are needed to clarify its role in fracture risk assessment.     

Secondary contributors to bone loss in osteoporosis related hip fractures

SUMMARY: Osteoporosis treatment of patients with hip fractures is necessary to prevent subsequent fractures. Secondary causes for bone loss are present in more than 80% of patients with hip fractures, and therefore, assessment of Vitamin D status, disorders in calcium absorption and excretion, monoclonal gammopathies, and renal function should be performed. Identifying and managing these disorders will improve detection and enhance treatment aimed at reducing the risk of recurrent fractures in older adults. INTRODUCTION: The purpose of this study was to determine the prevalence of disorders affecting bone and mineral metabolism in individuals with osteoporotic hip fractures. METHODS: Community dwelling individuals with hip fractures (HFx) 50 years of age and older. Assessment for vitamin D, renal and parathyroid status, calcium absorption, and plasma cell disorders. RESULTS: Of 157 HFx, mean age 70 +/- 10 years, HFx had higher creatinine (p = 0.002, 95% C.I. -0.09, 0.05); lower 25 OH vitamin D (p = 0.019, 95% C.I. 6.5, 2.7), albumin (p = 0.007, 95% C.I. 0.36, 0.009), and 24-h urine calcium (p = 0.024, 95% CI 51, 21) as compared to controls. More than 80% of HFx had at least one previously undiagnosed condition, with vitamin D insufficiency (61%), chronic kidney disease (16%) (CKD), monoclonal gammopathy (6%), and low calcium absorption (5%) being the most common. One case each of multiple myeloma and solitary plasmocytoma were identified. CONCLUSIONS: Osteoporosis treatment of HFx is necessary to prevent subsequent fractures. Secondary causes for bone loss are remarkably common in HFx; therefore, assessment of vitamin D status, disorders in calcium absorption and excretion, protein electrophoresis, and renal function should be performed. Identifying and correcting these disorders will improve detection and enhance treatment aimed at reducing the risk of recurrent fractures in older adults.     

骨水泥注射量对胸腰段椎体后凸成形术后并发再骨折的回顾性研究

目的:探讨球囊扩张后凸成形术(percutaneous kyphoplasty,PKP)治疗胸腰段骨质疏松性椎体骨折后并发再骨折与骨水泥注射量的关系。方法:自2006年1月至2008年12月对采用单侧经皮穿刺PKP术治疗的68例胸腰段骨质疏松性椎体骨折患者的临床资料进行回顾性分析,其中骨水泥注射量少于3ml(平均2.5ml)的患者30例(少量组),男11例,女19例;年龄60～91岁,平均(85.0±8.5)岁;骨水泥注射量大于4ml(平均4.5ml)的患者38例(多量组),男15例,女23例;年龄60～93岁,平均(86.0±9.2)岁。观察2组随访期内并发椎体再次骨折的因素并进行对比分析。结果:2组患者均获随访,随访时间3.4～5.1年,平均3.8年。少量组并发再次骨折13例(43.3%),其中强化椎体再骨折1例,上下邻节椎体骨折8例,远位节段椎体骨折4例;多量组并发再次骨折18例(47.3%),其中强化椎体再骨折2例,相邻椎体骨折10例,远位节段椎体骨折6例,2组比较差异无统计学意义(P>0.05)。结论:PKP治疗胸腰段骨质疏松性椎体骨折骨水泥注射量不是再次骨折的主要影响因素,并发骨折主要与骨质疏松的疾病自然进展有关,注射量以略超过球囊容积为宜。     

Hip axis length as an independent risk factor for hip fracture independently of femural bone mineral density in Caucasian elderly Brazilian women

Studies carried out in several countries and in different ethnic groups have suggested that the hip axis length (HAL) may be a risk factor for hip fractures.

To evaluate if the HAL is an independent risk factor for hip fractures in elderly Caucasian Brazilian women, this study includes 112 participants sustaining proximal femur osteoporosis. Through HAL and bone mineral density (BMD) measurements, a statistical analysis using a multivaried regression curve was done. HAL was significantly longer in women sustaining a hip fracture than in the control group (99.24 ± 5.9 mm vs. 96.95 ± 5.6 mm, P < 0.05). After adjusting the standard HAL deviation for neck and trochanter BMD, OR was 1.43 (IC 95% 0.29–1.07; P < 0.08). When HAL was categorized for 97.8 mm (average HAL in all women), OR was 2.24 (IC 95% 1.04–4.84; P < 0.05). In conclusion, HAL may be associated with risk of hip fracture regardless of age, weight or BMD of elderly Brazilian Caucasian women.     

Influence of fall related factors and bone strength on fracture risk in the frail elderly

Introduction When subjects are selected on the basis of fall risk alone, therapies for osteoporosis have not been effective. In a prospective study of elderly subjects at high risk of falls, we investigated the influence of bone strength and fall risk on fracture. Methods At baseline we assessed calcaneal bone ultrasound attenuation (BUA) as well as quantitative measures of fall risk in 2005 subjects in residential care. Incident falls and fractures were recorded (median follow-up 705 days). Results A total of 6646 fall events and 375 low trauma fracture events occurred. The fall rate was 214 per 100 person years and the fracture rate 12.1 per 100 person years. 82% of the fractures could be attributed to falls. Although fracture rates increased with decreasing BUA (incidence rate ratio 1.94 for lowest vs. highest BUA tertile, p<0.002), incident falls also affected fracture incidence. Subjects who fell frequently (>3.15 falls/per person year) were 3.35 times more likely to suffer a fracture than those who did not fall. Some fall risk factors such as balance were associated with the lowest fracture risk lowest in the worst performing group. Multivariate analysis revealed higher fall rate, history of previous fracture, lower BUA, lower body weight, cognitive impairment and better balance as significant independent risk factors for fracture. Conclusions In the frail elderly, both skeletal fragility and fall risk including the frequency of exposure to falls are important determinants of fracture risk.     

Ultrasound and dual X-ray absorptiometry densitometry in women with hip fracture

To assess the usefulness of the measurement of the os calcis by ultrasound, a method that probably reflects bone quality as well as density, we have studied 54 women with hip fracture of the proximal femur and a control group. Ultrasound evaluation of the os calcis [broadband ultrasound attenuation (BUA), speed of the sound (SOS), and a combined index (stiffness)], and bone mineral density (BMD) determination over the proximal femur by dual X-ray absorptiometry (DXA) were performed. Weight, BMD, and ultrasound values in the hip fracture patients were significantly lower than controls (P<0.001). The Z-scores for BUA and stiffness were not different than that for femoral neck. Ward's triangle or trochanteric BMD (between-1.7 and -1.5). The odds ratios determined by receiver-operating characteristics (ROC) analysis were greater at the femoral neck (25.1) and BUA (24.4). Intermediate values were found at stiffness (16.9), Ward's triangle (12.8), and trochanter (11.1), and lower values were obtained at SOS (4.2). In turn, patients with trochanteric hip fractures had a significantly lower femoral neck and Ward's triangle BMD, stiffness, and BUA than patients with cervical hip fractures. Comparing a subgroup of 30 women with hip fractures without vertebral fractures with an age-matched group of 87 women with osteoporotic vertebral fractures, both groups were of similar weight and BMD but all ultrasound values were significantly lower in the hip fractures compared with vertebral fracture patients (P<0.05-P<0.01). Our findings suggest that in women with hip fractures, ultrasound evaluation of the os calcis has diagnostic sensitivity comparable to DXA of the femur and could be useful to predict hip fracture risk. Ultrasound values are lower in hip fractures compared with vertebral fracture, age-matched women and in older compared with younger hip fracture patients.     

Body mass index as a predictor of fracture risk: A meta-analysis

Low body mass index (BMI) is a well-documented risk factor for future fracture. The aim of this study was to quantify this effect and to explore the association of BMI with fracture risk in relation to age, gender and bone mineral density (BMD) from an international perspective using worldwide data. We studied individual participant data from almost 60,000 men and women from 12 prospective population-based cohorts comprising Rotterdam, EVOS/EPOS, CaMos, Rochester, Sheffield, Dubbo, EPIDOS, OFELY, Kuopio, Hiroshima, and two cohorts from Gothenburg, with a total follow-up of over 250,000 person years. The effects of BMI, BMD, age and gender on the risk of any fracture, any osteoporotic fracture, and hip fracture alone was examined using a Poisson regression model in each cohort separately. The results of the different studies were then merged. Without information on BMD, the age-adjusted risk for any type of fracture increased significantly with lower BMI. Overall, the risk ratio (RR) per unit higher BMI was 0.98 (95% confidence interval [CI], 0.97–0.99) for any fracture, 0.97 (95% CI, 0.96–0.98) for osteoporotic fracture and 0.93 (95% CI, 0.91–0.94) for hip fracture (all p <0.001). The RR per unit change in BMI was very similar in men and women ( p >0.30). After adjusting for BMD, these RR became 1 for any fracture or osteoporotic fracture and 0.98 for hip fracture (significant in women). The gradient of fracture risk without adjustment for BMD was not linearly distributed across values for BMI. Instead, the contribution to fracture risk was much more marked at low values of BMI than at values above the median. This nonlinear relation of risk with BMI was most evident for hip fracture risk. When compared with a BMI of 25 kg/m², a BMI of 20 kg/m² was associated with a nearly twofold increase in risk ratio (RR=1.95; 95% CI, 1.71–2.22) for hip fracture. In contrast, a BMI of 30 kg/m², when compared with a BMI of 25 kg/m², was associated with only a 17% reduction in hip fracture risk (RR=0.83; 95% CI, 0.69–0.99). We conclude that low BMI confers a risk of substantial importance for all fractures that is largely independent of age and sex, but dependent on BMD. The significance of BMI as a risk factor varies according to the level of BMI. Its validation on an international basis permits the use of this risk factor in case-finding strategies.     

Fundamentals and pitfalls of bone densitometry using dual-energy X-ray absorptiometry (DXA)

Measurement of bone mineral density (BMD) with central dual-energy X-ray absorptiometry (DXA) is the current gold standard for diagnosing osteoporosis and for monitoring patients. Errors in demographic information, improper patient positioning, incorrect scan analysis, and mistakes in interpretation can all lead to a wrong clinical decision or action. This paper reviews the fundamentals of positioning, scan analysis, and interpretation for central DXA and highlights some of the common pitfalls that may lead to erroneous results.     

骨质疏松髋部骨折区骨微结构变化研究

目的 分析骨质疏松髋部骨折区张力侧骨小梁微结构的变化。方法 实验组选择16例低能量创伤致股骨颈骨折需要行髋关节置换的老年患者,术前行健侧髋部骨密度检测。因活体取材困难,故选取5根青年同种异体股骨为对照组。在实验组与对照组股骨颈张力侧骨小梁中,切取5mm×5mm×10mm的松质骨,行Micro-CT扫描分析微结构参数。分析两组之间微结构参数的差异及实验组患者微结构参数与骨密度之间关系。结果 实验组微结构：骨体积分数(BV/TV) 0.0645±0.0259,骨小梁数量(Tb.N) (0.8078±0.2212) mm-1,骨小梁厚度(Tb.Th ) (0.0836±0.0212) mm, 骨小梁距离(Tb.Sp) (1.2197±0.4492) mm,连接密度(Conn.D) 1.8577±1.0217, 结构模型指数(SMI) 1.7780±0.5168。对照组微结构：BV/TV 0.1470±0.0633,Tb.N (1.2692±0.1376)mm－1,Tb.Th (0.1201±0.0414) mm,Tb.Sp (0.6810±0.1129) mm,Conn.D 3.3585±1.7851,SMI 0.8781±0.6665。与对照组相比,实验组髋部张力侧松质骨小梁显著破坏,各微结构指标均有明显的改变,差异有统计学意义（P＜0.05）。实验组微结构参数与骨密度之间无相关性（P＞0.05）。结论 骨质疏松髋部骨折区张力侧骨小梁明显破坏,这可能是髋部骨折发生的重要原因之一。     

Young patients with hip fracture: a population-based study of bone mass and risk factors for osteoporosis

Introduction Hip fracture in young patients is rare. The present study was aimed to clarify the comorbidity pattern and reveal relevant risk factors for osteoporosis and fracture in this patient group.Materials and methods Using electronic diagnosis registers and lists of the operating theatres for the Oslo hospitals, patients with new hip fracture during two 1-year periods from May 1994 through April 1995 and from May 1996 through April 1997 were identified. All patients age 20–49 years at the time of fracture were included (n=49), and a detailed medical history was recorded. Thirty-two of the patients volunteered for examination and completed a questionnaire and interview to reveal risk factors for osteoporosis. Data from the Oslo Health Study served as reference material. Bone mineral density (BMD) was measured using dual x-ray absorptiometry, and Z-scores were calculated using healthy subjects from Oslo as reference.Results Of the patients identified, the median age was 40 years (range 25–49), and 63% were men. In 65% of the patients, the fracture occurred after a fall at the same level, in 16% it occurred after a fall from a higher level, and in 18% it occurred in a traffic accident. Twenty percent of the patients had a history of alcohol or drug abuse, 39% had neuromuscular diseases, and 12% had endocrine diseases. The patients examined had significantly more risk factors for osteoporosis than the reference population. The BMD expressed as Z-score for L2-4 was −1.0±0.9 (mean ± SD; p<0.001), for femoral neck was −1.5±1.0 (p<0.001), and for total body was −1.3±1.1 (p<0.001). BMD was significantly lower than in controls for patients sustaining low-energy and high-energy trauma. There was a negative correlation between the total number of risk factors and BMD for lumbar spine (r=−0.35, p<0.05), femoral neck (r=−0.37, p=0.04), and total body (r=−0.55, p=0.001), respectively.Conclusions The majority of the young patients with hip fracture have a history of low-energy trauma, comorbidity predisposing for falls or decreased bone strength, as well as several risk factors for osteoporosis. The BMD was significantly lower than in the reference population regardless of the trauma mechanism.