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Biomedical subjects

M J Haddaway

Publications and source records attributed to M J Haddaway.

9 recordsLinked to original sources
PubMed1996

The relative contribution of disc and vertebral morphometry to the angle of kyphosis in asymptomatic subjects.

In order to investigate the relative contributions of vertebra and inter-vertebral disk to kyphosis, a series of 100 asymptomatic healthy women (age range 39-91 years) were studied to evaluate lateral dorsal appearances and possible related parameters of bone loss. Subjects underwent lateral dorsal spine radiography and single photon absorptiometry of the radius. There was a significant decrease in physical height in relation to age (P < 0.001) and this was directly related to an increasing thoracic kyphosis (P < 0.005). The angle of kyphosis was better related to the average anterior disc height (P < 0.001) than to average anterior vertebral height. The vertebral body ratio, however (anterior/posterior height), was more strongly related to angle of kyphosis than was disk ratio. The results also showed a fall in the proximal and distal radial bone mineral content with age (P < 0.001). These findings suggest that dorsal kyphosis as part of the ageing process may be as closely related to the physical integrity of the disc as to the vertebral body. Hence, therapy for age related bone mineral loss may have limited effect on a kyphotic deformity of the dorsal spine in otherwise asymptomatic patients.

Absorptiometry, Photon↗
PubMed1994

Bone mineral content and density in healthy subjects and in osteogenesis imperfecta.

Lumbar spine bone mineral density in a cross sectional study of healthy subjects increased by 0.012 and 0.016 g/cm2/year in boys and girls respectively between 5 and 11 years of age. These rates increased five-fold in girls and threefold in boys between the ages of 11 and 13 years as a result of the bone mineral content increasing more rapidly than the coronal area at this age. By the age of 11 years the girls had 66% of the coronal area, 61% of the bone mineral density, and 41% of the bone mineral content of subjects aged 18-23 years. The ratio (lumbar spine bone mineral content/body weight) was constant in boys aged 6-13 years, but there were significant variations in girls. Femoral neck bone mineral density in both sexes changed little between 6 and 11 years and at 11 years was 69% of the adult values. Subjects with osteogenesis imperfecta had a low bone mineral density and bone mineral content for their age and weight. The z score of bone mineral density at the femoral neck was significantly lower than at the lumbar spine. In patients with recurrent fractures a low bone mineral density may help in identifying those with osteogenesis imperfecta and assist in their subsequent management.

Absorptiometry, Photon↗
PubMed1993

Vertebral deformity, bone mineral density, back pain and height loss in unscreened women over 50 years.

Bone mineral density (BMD) was measured in the lumbar spine using dual-energy X-ray absorptiometry in 222 unscreened women (aged 50-82 years), and information on back pain and historic loss of standing height was obtained at interview. Vertebral morphometry was performed on lateral spinal radiographs. The shape of the vertebral body was quantified using appropriate vertebral shape indices (VSIs), and vertebral deformities were identified using thresholds defined in terms of the means (M) and standard deviations (SD) of these VSIs for the whole group. Severity of deformity was defined as either grade 1 (M+2SD < VSI < M+3SD), grade 2 (M+3SD < VSI < M+4SD or grade 3 (VSI > M+4SD). Subjects with grade 1 vertebral deformities were older than subjects without such deformities, but did not have a reduced age-related Z-score of BMD. Grade 2 wedge and concave deformities were associated with a reduced age-related Z-score of BMD, suggesting that the aetiology of such deformities is closest to conventional concepts of 'osteoporotic fracture'. Grade 3 deformities were associated with neither increased age nor decreased BMD. Stature decreased in these subjects with age. Subjects reporting historic height loss had a higher mean number of wedge deformities. Subjects with back pain did not have a higher incidence of vertebral deformity than subjects without, confirming that many deformities were asymptomatic. Neither back pain nor historic loss of height were found to be associated with low spinal BMD.

Absorptiometry, Photon↗
PubMed1993

Vertebral morphometry in women aged 50-81 years.

Vertebral dimensions and vertebral shape indices (VSI) were investigated in T4-L4 in 926 females aged 50-81 years. The most consistent finding was the increase of inferior antero-posterior dimension with age. Wedging and concavity also increased with age but the changes were not significant at all vertebral levels. The value of VSIs also varied with level. Thus a particular degree of VSI, considered normal at one level or at one age, would be outside the reference range at a different level or age group. The number of subjects identified as osteoporotic by skewness (5.4%) or in excess of three standard deviations from the mean (6.5%) was much lower than in recent reports from North America. The number of subjects contributing to a skewed distribution increased with age from 0.5% at 55-59 years to 10.0% at 75-79 years. Change with age in the antero-posterior dimension could increase load-bearing area in older subjects, but the decline in bone density will be increased as a declining bone mineral content occupies a larger volume.

Aged↗
PubMed1993

A computerized technique for vertebral morphometry.

A new technique for morphometric measurement of vertebral bodies has been described, in which a computerized image analysis system was used to digitize and measure standardized lateral radiographs of the thoracic and lumbar spine. The sources of error in the radiographic system and the image analysis system were assessed using vertebral phantoms and test images. Oblique projection in the radiographic image of a vertebra did not produce a significant error in the measured area. The radiographic magnification was approximately 35%. Optical non-uniformity was detected in the image analysis system, and was ascribed to the lens optics. The maximum intra-observer and inter-observer variations in vertebral area were 3.1% and 5.3% respectively for experienced observers. The technique is applicable to clinical studies of large populations, and has value in investigating vertebral deformity in the management of metabolic bone disease.

Female↗
PubMed1992

Bone mineral density in healthy normal women and reproducibility of measurements in spine and hip using dual-energy X-ray absorptiometry.

Bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA) has been measured in 394 healthy normal women. BMD is highest at the end of the 3rd decade and declines from 45 to 75 years by 0.0095 g/cm2/year in the lumbar spine and by 0.0052-0.0078 g/cm2/year in the upper femur depending on the site. BMD appears to increase in the 8th decade. Reproducibility (coefficient of variation (CV) of repeated measurements) was lowest in the lumbar spine (1.45%) and highest in Ward's triangle (4.29%). CV was not influenced by age at any site and by osteoporosis only in the femoral neck. BMD increased from L2 to L4 but the increase could not wholly be accounted for by the size of the vertebra, suggesting that the posterior elements were contributing to the observed increase of bone density.

Absorptiometry, Photon↗