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Byline: B. M. Ingle (1), R. Eastell (1) Keywords: Key words:Ankle fracture -- Broadband ultrasound attenuation -- Dual-energy X-ray absorptiometry -- Velocity of sound Abstract: Ankle fracture is one of the most common fractures in adults, particularly postmenopausal women. Few studies have examined the bone mineral density (BMD) and ultrasound properties of bone close to the site of fracture in patients with ankle fracture. The aim of this study was to evaluate these measurements in women with ankle fractures compared with controls. We studied 31 healthy post-menopausal women ages 50--79 years (mean age 63.2 +- 3.3 years) from a population-based group and 31 postmenopausal women ages 52--76 years (mean age 61.2 +- 2.2 years) with an ankle fracture. Distal tibia and fibula BMD were measured by dual-energy X-ray absorptiometry using the Hologic QDR 1000/W densitometer. In addition to total distal and tibia BMD, three subregions were automatically selected: ultradistal, middle and one-quarter regions. Speed of sound (SOS) and broadband ultrasound attenuation (BUA) of the calcaneus were measured using the Lunar Achilles+ (LA+) and CUBA Clinical (CC). In addition to SOS and BUA, LA+ Stiffness Index (SI) was also measured. The nondominant limb was measured in the population group and the contralateral limb in the ankle group. Differences between the groups were determined using t-tests. The ankle fracture group was heavier than the control group by an average of 10 kg. BMD measurements were therefore adjusted for weight. There were no significant differences between the ankle fracture and control groups in lumbar spine BMD, total or regional ankle BMD or calcaneal BUA. However, calcaneal SOS was decreased in the ankle fracture group when measured on the LA+ and CC by 50 m/s (--2.0 SD units, p&lt 0.001) and 19 m/s (--0.5 SD units, p&lt 0.01) respectively. LA+ SI was decreased in the ankle fracture group by 14 units (--1.1 SD units, p&lt 0.001). In conclusion, ankle fracture is not a typical osteoporotic fracture. However, there may be structural changes in the bone (unrelated to bone density) which result in increased fragility and susceptibility to fracture. Author Affiliation: (1) Bone Metabolism Group, Section of Medicine, Division of Clinical Sciences, University of Sheffield, Sheffield, UK, GB Article note: Received: 7 May 2001 / Accepted: 29 August 2001

Byline: L. Ferrar (1), G. Jiang (1), R. Eastell (1) Keywords: Key words:Absorptiometry -- Deformity -- Osteoporosis -- Radiography -- Vertebra Abstract: Vertebral wedge angle is greater in older men than in women of similar age, and increases with age in men. Wedge angle may depend less on bone size than other methods (for example, height ratios), and thus could be more effective at identifying wedge deformities. We aimed to compare mean wedge angle measured by morphometric X-ray absorptiometry (MXA) in young men and women, to assess the effect of age on wedge angle in women, and to compare wedge angle and anterior--posterior (ha/hp) height ratios for the identification of vertebral deformities. Mean wedge angle was similar in normal men (n= 46) and women (n= 106) ages 22--50 years, and did not change significantly with age in normal women ages 22--83 years (n= 222). MXA reference intervals for ha/hp ratios (trimmed mean minus 3.0 SD) and wedge angle (trimmed mean + 3.0, 2.5 and 2.0 SD) were used to identify vertebral wedge deformities in 83 women with osteoporosis, ages 49-- 87 years. For agreement with semiquantitative assessment of radiographs (SQ), kappa (Io) = 0.76 for wedge angle mean plus 2.0 SD, and 0.74 for ha/hp height ratio mean minus 3.0 SD. Sensitivity was marginally better for wedge angle plus 2.0 SD than for ha/hp when all SQ grades of deformity were included, but there was no difference between methods for detection of moderate to severe deformities (grades 2 to 3). Diagnostic values for the two approaches were broadly similar. The results of this analysis do not provide strong evidence for the preferential use of the wedge angle approach. Author Affiliation: (1) Bone Metabolism Group, Section of Medicine, Division of Clinical Sciences, University of Sheffield, Sheffield, UK, GB Article note: Received: 2 August 2000 / Accepted: 23 May 2001

Byline: L. Ferrar (1), G. Jiang (1), R. Eastell (1) Keywords: Key words:Absorptiometry -- Deformity -- Osteoporosis -- Precision -- Radiography -- Vertebrae Abstract: Morphometric X-ray absorptiometry (MXA) is a low-radiation technique used for the identification of vertebral deformities. The reliability of MXA measurements is dependent on the precision of the technique, and this is influenced by system error, variability associated with morphometric analysis, and variability within study populations. Short-term precision in vivo affects the identification of prevalent deformities, and may vary according to the age and health status of the study population. The aims of this study were to measure short-term precision in vitro and in vivo for MXA, and to compare intraoperator variability for repeat marking of radiographs in morphometric radiography (MRX) and scan images in MXA. For short-term precision in vitro (based on 30 consecutive MXA phantom scans), the coefficient of variation (CV) was approximately 1%. lntraoperator variability for repeat marking of baseline radiographs and MXA scans (marked without the compare facility) in a population-based group of 32 postmenopausal women, was significantly lower for MRX (CV for vertebral heights = 1.5%) than for MXA (CV= 2.9%). The CV for duplicate same-day MXA scans performed in subjects with osteoporosis (n= 20) was 2.2 % for vertebral heights between T8 and L4 using the compare facility, and 4.8% when scans were analyzed without the compare facility. We conclude that short-term precision for MXA is good for vertebrae T8 to L4, but the technique is limited due to poor image resolution in the upper thoracic vertebrae. Intraoperator variability for repeat marking was lower for MRX, but the error associated with marking MXA scans remained below the minimum change required for identification of a vertebral deformity. Author Affiliation: (1) Bone Metabolism Group, Section of Medicine, Division of Clinical Sciences, University of Sheffield, UK, GB Article note: Received: 31 July 2000 / Accepted: 6 February 2001

Byline: Y. M. Henry (1), R. Eastell (1) Keywords: Key words:Bone density -- Bone remodeling -- Ethnic groups -- Sex Abstract: Generally, the incidence of osteoporotic fracture is lower in black populations and in men. These effects of ethnicity and gender may result from differences in peak bone mineral density (PBMD) and bone turnover (BT), which in turn are affected by bone size. Therefore, the aims of this study were to examine the effects of ethnicity and gender on bone mineral density (BMD) and BT in young African-Caribbean and Caucasian adults, and to adjust for the effect of bone size on BMD and BT. BMD was measured at the lumbar spine, L2--L4 (LS), total body (TB) and femoral neck (FN) by dual-energy X-ray absorptiometry in 44 blacks (16 men, 28 women) and 59 whites (28 men, 31 women) ages 20--37 years. We measured serum bone-specific alkaline phosphatase (BAP) and serum osteocalcin (OC) as markers of bone formation and urinary immunoreactive free deoxypyridinoline (ifDpd) and crosslinked N-telopeptide of type I collagen (NTx) as markers of bone resorption. To adjust the data for any differences in bone size, we calculated: (a) bone mineral apparent density (BMAD), an estimated volumetric bone density which attempts to normalize BMD measurements for bone size and (b) bone resorption markers as a ratio to total body bone mineral content (TB BMC). Two-way analysis of variance was used to compare the effects of race and gender, and to test for any interaction between these two factors. Blacks had higher BMD compared with whites at the TB (p&lt 0.001), LS (p= 0.0001) and FN (p= 0.0005). This increase remained significant at the LS only after calculating BMAD. Men had higher BMD at all sites (except at the LS). This increase was no longer significant at the FN after calculating BMAD, and LS BMAD was actually greater in women (p&lt 0.0001). Blacks and whites had similar concentrations of turnover markers, but men had higher bone turnover markers than women (BAP, p&lt 0.0001 OC, p= 0.002 ifDpd, p= 0.03 NTx, p&lt 0.0001). This increase in bone resorption markers was no longer significant after adjusting for TB BMC (except for NTx in whites). We conclude that the skeletal advantage in blacks during young adulthood is not explained by bone size. However, it seems probable that bone size effects partially explain gender differences in BMD and bone turnover. Author Affiliation: (1) Bone Metabolism Group, Section of Medicine (NGHT), Division of Clinical Sciences, University of Sheffield, Sheffield, UK, GB Article note: Received: 2 February 1999 / Accepted: 2 December 1999