The identification of vertebral fracture in osteoporosis is based mainly on the identification of abnormal variation in vertebral shape, but this can be misleading in the presence of a non-fracture deformity or normal variant of vertebral shape. Qualitative identification of vertebral fracture (Qual) is influenced by the subjectivity of the approach, and although more objective, the semiquantitative method (SQ) can be difficult to apply. In addition, there has been little independent evaluation of SQ in relation to other approaches. We aimed to evaluate a new algorithm-based approach for the qualitative identification of vertebral fracture (ABQ) and to compare it with SQ and Qual. Two radiologists reported spinal radiographs for 372 postmenopausal women using Qual (reader 1), and SQ and ABQ (reader 2). Non-fracture deformities and normal variants were also reported using Qual and ABQ. The prevalence of vertebral fracture by subjects was higher for SQ (24%) than for Qual (11%) and ABQ (7%). Agreement was poor between SQ and the other methods, and moderate between Qual and ABQ. Twenty-two women with vertebral fracture were agreed by all three methods, similar to the total identified by ABQ (25 women). Seventeen women diagnosed with fracture by Qual, had non-fracture deformity or normal variant (but no fracture) according to ABQ. Of the women with SQ fractures, 53% and 70% were identified negative for fracture but positive for non-fracture deformity or normal variant by ABQ and Qual. The main sources of discrepancy between SQ and the other methods were Scheuermann's disease, normal variation, and degenerative change accompanied by short anterior vertebral height. For all methods, bone mineral density (BMD) and BMD Z-scores were lower in women with vertebral fractures than in those with no fractures. Bone mineral density and BMD Z-scores were also lower at the lumbar spine and total body in women with vertebral fractures according to Qual and ABQ than they were for SQ, and were lower in women with SQ fractures agreed by Qual and ABQ, compared with those diagnosed negative for fracture by Qual and ABQ (p<0.01). We conclude that poor agreement between methods arises mainly from difficulties in differentiating true fracture from non-fracture deformity. Our new approach attempts to address this problem but requires further testing in a larger study population.

Objectives-To determine the prevalence of vertebral fracture in postmenopausal women with steroid treated rheumatoid arthritis (RA), and whether the risk of vertebral fracture could be predicted from measurements of bone mineral density (BMD).Methods-Vertebral deformities were defined from spine radiographs in 76 postmenopausal women with steroid treated RA (aged 50-79 years) and 347 age matched women from a population based group, using a morphometric technique. Lumbar spine (LS) BMD was measured by dual energy x ray absorptiometry. Results-The odds ratio for vertebral fracture in the women with RA was 6-2 (95% confidence interval 3*2 to 12-3). The decrease in LS-BMD was less than expected for the observed prevalence of vertebral fracture and, among the women with RA, LS-BMD was not lower in those with vertebral fractures. Conclusions-We conclude that patients with steroid treated RA may have abnormal bone quality, and that LS-BMD cannot be used to predict the risk of vertebral fracture in these patients.

ABSTRACT

Objectives-To determine whether there was a generalised increase in bone mineral density (BMD) in spinal osteoarthrosis (OA), and to determine the mechanism of this possible protection against osteoporosis as assessed by biochemical markers ofbone turnover. Methods-We studied 375 women (ages 50 to 85) from a population based group. Spinal OA was defined from radiographs as the presence of degenerative changes affecting intervertebral or facet joints. BMD of the lumbar spine (LS), femoral neck (FN) and total body (TB) was measured by dual energy x ray absorptiometry (Lunar DPX). Bone turnover rates were estimated from measurement of biochemical markers of bone formation and resorption (urine deoxypyridinoline (Dpyr) and serum bone specific alkaline phosphatase (BAP)). Results-BMD at each site was greater in the women with spinal OA (mean increase in LS-BMD 7 9%, 95%0 confidence interval (CI) 1-0 to 15-1; TB-BMD 8-4%, 95% CI 1P9 to 9 7; FN-BMD 6-4/o, 95% CI 0-3 to 12.6). (FN), although the increase at this site was smaller. Increased BMD in the presence of OA may, therefore, be greatest in the region affected by OA, but may also affect the skeleton generally.An increase in measured BMD in a region affected by OA may result from artefactual error caused by the presence of osteophytes, joint space narrowing and sclerosis within the region of interest. Alternatively, it may reflect a generalised effect of OA on the skeleton, or a combination of the two. If OA has a generalised effect on the skeleton, then study of bone metabolism in patients with OA may be important in understanding the pathophysiology of osteoporosis.Studies in patients with OA are complicated by the heterogeneous nature of the disease and by the poor correlation between symptoms and radiological signs.8 It is therefore necessary to determine the prevalence of OA from radiological surveys. It is also unknown whether all degenerative changes identified on radiographs are pathological, or whether minor changes may represent physiological changes of aging.There has been little study of the underlying mechanism of the interaction between bone mass and OA. The development of noninvasive biochemical assays for markers ofbone resorption and formation enable estimation of bone turnover in large cohorts of subjects. The urinary excretion of pyridinium crosslinks has been shown to be increased in patients with large joint OA,"'2 suggesting an increased rate of bone turnover in this condition; however, none of these studies allowed for the fact that there may have been an increased skeletal mass to account for the increase in crosslink excretion. There have been no reports of biochemical markers in subjects with spinal OA.It is now possible to make accurate and precise measurements of BMD using dual energy x ray absorptiometry (DXA). This technique enables measurement of the BMD of the whole skeleton, in addition to measurements at the IS and EN. It is also possible to make accurate measurements of the BMC of the whole skeleton which can be used to no...