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N A Barrington

Publications and source records attributed to N A Barrington.

At least 19 recordsLinked to original sources
PubMed2004

Comparison of methods for the visual identification of prevalent vertebral fracture in osteoporosis.

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.

Aged↗
PubMed2001

Effect of pamidronate in preventing local bone loss after total hip arthroplasty: a randomized, double-blind, controlled trial.

Acute periprosthetic bone loss occurs after total hip arthroplasty. Bone loss undermines the support of the implant and may contribute to prosthetic failure. At present, there is no established prophylaxis for this process. We studied the effect of a single-dose infusion of 90 mg of pamidronate on early periprosthetic bone mineral density (BMD), biochemical markers of bone turnover, radiological, and clinical outcome in a 26-week, prospective, randomized, double-blinded study of 47 men and women undergoing total hip arthroplasty. Pamidronate therapy led to a significant reduction in bone loss compared with placebo for both the proximal femur and the pelvis (repeated measures analysis of variance [ANOVA]); p = 0.001 and p = 0.01, respectively). Pamidronate therapy was associated with suppression of all biochemical markers of bone turnover compared with placebo (repeated measures ANOVA; p < 0.05 for all comparisons), with the exception of urinary free deoxypyridinoline. Pamidronate did not interfere with the clinical improvement in symptoms after total hip arthroplasty, or radiological outcome, and was not associated with an increase in adverse events. This study provides clinical data on the efficacy and safety of bisphosphonates for the prevention of bone loss after total hip arthroplasty and supports the establishment of larger-scale clinical trials to determine the long-term clinical efficacy of this intervention using implant failure as the primary endpoint.

Aged↗
PubMed2000

Identification of vertebral deformities in women: comparison of radiological assessment and quantitative morphometry using morphometric radiography and morphometric X-ray absorptiometry.

Our aim was to compare normal vertebral reference values for morphometric radiography (MRX) and morphometric X-ray absorptiometry (MXA) and to compare these methods for the identification of vertebral deformities. We calculated MXA reference values (Hologic QDR 4500 A) for 327 women (ages 22-88 years) randomly selected from local General Practice lists in Sheffield, U.K. MRX reference values were calculated from spinal radiographs for 123 of these subjects (ages 56-88 years). We used these reference values to identify deformities in the MRX and MXA reference populations and in 83 women with osteoporosis (ages 49-87 years). We observed differences in mean deformity of vertebral height ratios measured by MRX and MXA, especially for the mid-to-posterior ratio. We compared agreement between quantitative methods (MRX and MXA) and qualitative radiological assessment. Severity of deformity was defined by semiquantitative (SQ) assessment. Agreement was moderate for MRX (k = 0.59; 95% CI = 0.43-0.77) and for MXA (k = 0.47; 95% CI = 0.29-0.66) in the reference population. Agreement was good for MRX (k = 0.86; 95% CI = 0.82-0.89) and MXA (k = 0.71; 95% CI = 0.66-0.75) in the osteoporotic population. MRX and MXA correctly identified a greater proportion of moderate or severe deformities compared with mild deformities. Sensitivity, specificity, predictive values, and accuracy were slightly better for MRX than for MXA. Although MXA agrees well with qualitative radiological assessment, the large proportion of vertebrae excluded from analysis because of poor image quality limits the diagnostic value of the technique. Reference intervals should be technique specific.

Absorptiometry, Photon↗
PubMed1995

Risk of vertebral fracture and relationship to bone mineral density in steroid treated rheumatoid arthritis.

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.

Aged↗
PubMed1995

Bone mineral density and bone turnover in spinal osteoarthrosis.

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 of bone 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% confidence interval (CI) 1.0 to 15.1; TB-BMD 8.4%, 95% CI 1.9 to 9.7; FN-BMD 6.4%, 95% CI 0.3 to 12.6). Twenty four hour urinary excretion of Dpyr, corrected for TB bone mineral content, and serum BAP were 19% lower in the women with spinal OA (95% CI for Dpyr 4.3 to 31.9%; for BAP 6.3 to 32.0%). CONCLUSIONS: Spinal OA is associated with a generalised increase in BMD and a decreased rate of bone turnover. This suggests that the protective effect of spinal OA against osteoporosis may be mediated by decreased bone turnover.

Absorptiometry, Photon↗
PubMed1995

Fractures of the lateral process of the talus--the value of lateral tomography.

We present three cases of fractures of the lateral process of the talus, where routine anteroposterior and lateral radiographs showed an abnormality but were insufficient to assess the degree of bony injury, which is important for clinical management. Lateral tomography provided good diagnostic and anatomical detail. The diagnosis and treatment of this unusual and often missed fracture is discussed.

Adult↗
PubMed1993

Impact of anomalous vertebral segmentation on measurements of bone mineral density.

In anteroposterior (AP) bone mineral density (BMD) measurements of the lumbar spine (LS), the presence of ribs is used to identify vertebra T12. Similarly, in lateral LS-BMD measurements, the position of the iliac crest is used to identify the lumbar vertebrae. The aim of this study was to determine the impact of variations in spinal segmentation and iliac crest position on BMD measurements. In 375 women (ages 50-85 years) radiographs were taken of the thoracic and lumbar spine, as well as AP measurement of LS-BMD, by dual-energy x-ray absorptiometry (DXA). In 121 subjects lateral decubitus LS-BMD was also measured. Anomalous spinal segmentation was found in 16.5%, and L1 would have been incorrectly identified on the AP-DXA image in 13%. The change in BMC and BMD between adjacent vertebrae was greater in the upper than the lower lumbar spine. Misidentification of L1 for T12 resulted in underestimation of the bone mineral content in grams (BMC) of L1 by a mean of 11.5 +/- 14.4% (SD; range -33.5 to 33.5%). For the usual region of interest, L2-4, the BMC (g) was underestimated by 8.4 +/- 8.7% (range -1.5 to 29.2%), with the BMD (g/cm2) underestimated by 3.6 +/- 4.8% (range -5.4 to 11.6%). The position of the iliac crest on the lateral decubitus DXA scans would have led to misidentification of either L2 or L4 for L3 in 15 cases (12%). This resulted in the BMD of L3 being underestimated by 2.7 +/- 19.4% (range -242.4 to 34.6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1992

The accessory navicular--an important cause of medial foot pain.

The accessory navicular is a commonly occurring accessory ossicle of the foot. In most instances this is an incidental finding. In some patients, the accessory navicular is the direct cause of foot pain. We present 10 such cases. The typical clinical picture is of a young female patient who presents with chronic or acute on chronic medial foot pain centered over the medial side of the navicular. The patient is usually physically active on her feet and localizes the pain accurately. Plain radiography reveals an accessory navicular united to the navicular by a synchondrosis (Type II). The diagnosis can be confirmed by showing increased localized uptake of isotope on a technetium 99m MDP bone scan. In some cases, the accessory navicular is mistaken for a fracture. Awareness of this accessory ossicle causing such symptoms should lead to the correct diagnosis.

Adult↗
PubMed1991

Case report: tuberculosis of the spine--an unusual presentation.

Tuberculosis of the posterior spinal elements is rare but has a high incidence of neurological morbidity and can cause diagnostic confusion. A case is reported in which the most prominent radiological feature was destruction of the lateral aspects of the vertebral bodies. The cause of this appearance is discussed with reference to previous descriptions of this condition.

Antitubercular Agents↗
PubMed1990

The effect of forced expiration on the uniformity of 99Tcm-DTPA aerosol ventilation images in patients with excess sputum production.

This study examines the use of the forced expiratory technique (FET) as a means of improving the uniformity of radionuclide aerosol ventilation images in patients with excess sputum production. Ventilation images are objectively classified by two computer derived indices to characterize the degree of radioaerosol clumping and overall uniformity. In a series of twenty five patients with a long-standing history of daily sputum production, images acquired before and after forced expiration and again after a second ventilation immediately following FET showed no significant change in either index. The results obtained do not provide evidence to support the routine use of FET in conjunction with radioaerosol scintigraphy. The method of image classification correlates well with a visual assessment of image uniformity and has general application.

Aerosols↗
PubMed1988

Lumbar lateral canal entrapment: clinical, radiculographic and computed tomographic findings.

The radiculographic and computed tomographic findings in those nerve roots compressed by lumbar lateral canal entrapment have been assessed in a prospective series of 44 patients in whom such entrapment was found at surgery. The radiological procedures were reported by radiologists who were unaware of the clinical findings. Radiculography was performed in 41 of the patients and enabled the site or sites of entrapment to be correctly predicted in 62% of patients undergoing primary decompression and in 42% of patients undergoing revision surgery. Computed tomography (CT) was performed in 24 of the patients and enabled entrapment to be correctly predicted in 75% of the patients in both groups. We conclude that computed tomography is superior to radiculography in demonstrating lumbar lateral entrapment, and should usually be reserved for patients in whom operation or other intervention is warranted on clinical grounds. Otherwise false positive results may occur, especially in elderly patients, although the true incidence of false positive results in this condition is not known and has not been assessed in this study.

Adult↗
PubMed1988

The radiology of bone and joint infection.

Many of the classic radiological features of skeletal infection are now seldom seen due to modern imaging techniques enabling early diagnosis and prompt treatment. It is important to remind ourselves of the potential complications which may develop when the correct diagnosis is delayed or missed.

Actinomycosis↗