Anatomical distribution of vertebral fractures: comparison of pediatric and adult spines.

SUMMARY: We compared the distribution of vertebral fractures in adults and children and found that fractures occurred in different locations in the two age groups. This likely relates to the different shape of the immature spine. INTRODUCTION: We hypothesized that the anatomical distribution of vertebral fractures (VF) would be different in children compared to adults. METHODS: We compared the distribution of VF defined using the Genant semi-quantitative method (GSQ method) in adults (N = 221; 545 fractures) and in children early in the course of glucocorticoid therapy (N = 44; 94 fractures). RESULTS: The average age in the adult cohort was 62.9 years (standard deviation (SD), 13.4 years), 26% was male, the mean lumbar spine Z-score was -1.0 (SD, 1.5), and the corresponding T-score was -2.4 (SD, 1.4). The pediatric cohort median age was 7.7 years (range, 2.1-16.6 years), the mean lumbar spine Z-score was -1.7 (SD, 1.5), 52% was male, and disease categories were acute lymphoblastic leukemia (66%), rheumatological conditions (21%), and nephrotic syndrome (14%). The VF distribution was biphasic in both populations, but the peaks differed in location. In adults, the peaks were at T7/T8 and at T12/L1. In children, the focus was higher in the thoracic spine, at T6/T7, and lower in the lumbar spine, at L1/L2. When children were assessed in two age-defined sub-groups, a biphasic VF distribution was seen in both, but the upward shift of the thoracic focus to T6 was observed only in the older group, with the highest rates of fracture present between ages 7 and 10 years. CONCLUSIONS: These results suggest that the anatomical distribution of VF differs between children and adults, perhaps relating to the different shape of the immature spine, notably the changing ratio of kyphosis to lordosis.

The accuracy of clinical kyphosis examination for detection of thoracic vertebral fractures: comparison of direct and indirect kyphosis measures.

OBJECTIVE: To compare the accuracies of two simple physical examination maneuvers for detecting the presence of thoracic vertebral fractures (VF) diagnosed by radiography: direct measurement of kyphosis angle (KA, in degrees) and indirect measurement using wall-occiput distance (WOD, in cm). METHODS: Subjects were 280 women (average age, 54.5 years; range, 18-92) referred for assessment of osteoporosis. KA was measured from T4 to T12 using a digital inclinometer while WOD was measured with the patient in a standardized position. VF were diagnosed on radiographs using semi-quantitative morphometry. RESULTS: KA and WOD were moderately correlated (r = 0.72, p<10(-11)). KA increased by 3.7(o) (95% CI, 2.6-4.8(o)) for each VF (p = 4x 10(-11)) and WOD rose 1.3 cm (95% CI, 0.8-1.7 cm) per VF (p = 2 x 10(-11)). The areas under the receiver operating characteristic curves were 0.72 (95% CI, 0.65-0.79) for KA and 0.76 (95% CI, 0.69-0.82) for WOD, which were not significantly different (p = 0.13). CONCLUSIONS: Given similar performances of direct and indirect measures of kyphosis, we propose that WOD should be used in clinical practice, with a clinical threshold of WOD>4.0 cm as an indication to consider spine radiography. At this WOD threshold, sensitivity was 41% (95% CI, 31-52%) and specificity was 92% (95% CI, 87-95%). WOD should be considered for use in the clinical assessment of osteoporosis patients.

The accuracy of historical height loss for the detection of vertebral fractures in postmenopausal women.

Historical height loss (HHL) can be calculated as the difference between a patient's tallest recalled height (TRH) and the current measured height (MH). We have examined the accuracy of HHL as a clinical test for the detection of prevalent vertebral fractures. Subjects were postmenopausal women aged 50 or older who had been referred for specialist assessment of osteoporosis risk (n=323; average age 66.0+/-9.2 years; range 50-92 years). MH was determined using a wall-mounted stadiometer. The presence of prevalent vertebral fractures was assessed by radiographic morphometry, with fracture defined as a vertebral height ratio<0.8. The positive likelihood ratio (LR+) for fracture was relatively flat until HHL>6.0 cm. With HHL from 6.1 to 8.0 cm, the LR+ was 2.8 [95% confidence interval (95%CI), 1.3, 6.0]. When HHL was >8.0 cm, the LR+ was 9.8 (95% CI, 3.0, 31.8). The area under the receiver operating characteristics curve for the ability of HHL to detect fracture was 0.66 (95% CI, 0.59, 0.72). At HHL>6.0 cm, sensitivity was 30% (95% CI, 22, 37%), and specificity was 94% (95% CI, 90, 97%). The positive predictive value was relatively low across a range of theoretical prevalence, rising above 80% only at very high prevalence rates (>50%). In contrast, the negative predictive value was high at the prevalence rates seen in most clinical practice, and dropped below 80% only when the prevalence exceeded 25%. This study shows that HHL6.0 cm should have spine radiographs to examine for the presence of vertebral fractures.

Preliminary findings from a teleultrasound study in Alberta.

BACKGROUND AND OBJECTIVES: Ultrasound practice in Alberta requires direct supervision by an ultrasound-accredited specialist physician (sonologist). This requirement limits access to ultrasound examinations in many rural communities. A prospective study was performed to evaluate the adequacy of teleultrasound service in High Level, Alberta, with remote sonologist supervision from Edmonton, Alberta. METHODS: A total of 146 patients were evaluated in two groups. Group A (72 patients) was evaluated by both an on-site radiologist in High Level and a remote supervising radiologist in Edmonton. Group B (74 patients) was evaluated only by the remote supervising radiologist in Edmonton. The teleultrasound service included digital store-and-forward capabilities using a commercially available teleradiology system, with videoconferencing review for real-time scanning. RESULTS: The teleultrasound service was helpful to the referring physician. It made transfer unnecessary in 42% of patients, and the results of the ultrasound assessment influenced management in 59% of patients. The sonographer on site and the remote radiologists agreed on the quality of the images. The information required for diagnosis was available from the sonographer's study in the majority of cases, with second-look scanning by the on-site radiologist or videoconferencing by the remote radiologist providing a major new diagnosis in only 1% of patients. CONCLUSION: Teleultrasound service to High Level could be provided reliably with remote supervision, comparable to direct on-site supervision.

I-131 metaiodobenzylguanidine uptake in a parathyroid adenoma.

We describe a patient with multicentric small bowel carcinoids, severe hypertension, primary hyperparathyroidism, and multiple parathyroid adenomas. Intense uptake of I-131 metaiodobenzylguanidine (MIBG) occurred in a parathyroid adenoma. There was no biochemical evidence of catecholamine secretion by the tumor but elevated serum levels of parathyroid hormone were demonstrated. We suspect that occasional parathyroid adenomas, like other APUDomas, may give false positive results when MIBG imaging is used to search for pheochromocytomas. This observation supports the inclusion of the parathyroid chief cells in the amine precursor uptake and decarboxylation (APUD) cell system.

Experience with I-131-metaiodobenzylguanidine (MIBG): a retrospective study.

We report a retrospective study of two years experience with I-131-metaiodobenzylguanidine (MIBG). I-131 MIBG was prepared locally and was found to have decreased background activity as compared with other available commercial preparations from Great Britain and the United States. Fifty-nine patients were studied with a total of 65 scans. The study included 11 members of a family with multiple endocrine adenomatosis (MEA) type II syndrome. Of 16 patients found to have abnormal scans, 12 had disease confirmed surgically. These cases consisted of nine pheochromocytomas, one paraganglioma, one neurilemmoma, and one neuroblastoma. MIBG scans for pheochromocytoma detection had an accuracy of 94.5%, a sensitivity of 100%, and a specificity of 93.5% in this study of patients with a high prior probability of the disease.