Bone density and body composition on the Pacific rim: a comparison between Japan-born and U.S.-born Japanese-American women.

Bone mineral density (BMD) of total body, spine, and proximal femur and the percentage of body fat in 151 U.S.-born Japanese-American women and 137 Japan-born immigrant Japanese-American women living in San Diego, California were measured using dual-energy x-ray absorptiometry. These data were compared with unpublished data from Japanese women obtained in previous studies in Hamamatsu, Japan. The age-adjusted BMD for the spinal level, femoral neck, Ward's triangle, trochanter, and total body, respectively, of U.S.-born Japanese-American women were 10.2, 9.8, 9.9, 9.2, and 2.7% higher than those of native Japanese women. The U.S.-born Japanese-American women had significantly higher body fat than immigrant Japanese-American women. Furthermore, the immigrant women had higher BMD and higher body fat than their native Japanese counterparts; however, no significant total-body BMD differences were found among the three groups after age, height, and weight were adjusted. The U.S.-born Japanese-American women had BMD values equivalent to those of white normals at the spine and femur. Significant life-style differences between U.S.-born and immigrant Japanese-American women were noted. Weight, exercise, early menarche, and years of lifetime estrogen exposure correlated positively with BMD. The significant negative correlates of BMD were age, smoking, and percentage of body fat. Our study presents data suggesting that immigration to the United States has produced a higher BMD in Japanese-American women that is attributable to changes in life-style and diet.

Dual-energy X-ray absorptiometry derived structural geometry for stress fracture prediction in male U.S. Marine Corps recruits.

A total of 626 U.S. male Marine Corps recruits underwent anthropometric measurements and dual-energy X-ray absorptiometry (DXA) scans of the femoral midshaft and the distal third of the tibia prior to a 12 week physical training program. Conventionally obtained frontal plane DXA scan data were used to measure the bone mineral density (BMD) as well as to derive the cross-sectional area, moment of inertia, section modulus, and bone width in the femur, tibia, and fibula. During training, 23 recruits (3.7%) presented with a total of 27 radiologically confirmed stress fractures in various locations in the lower extremity. After excluding 16 cases of shin splints, periostitis, and other stress reactions that did not meet fracture definition criteria, we compared anthropometric and bone structural geometry measurements between fracture cases and the remaining 587 normals. There was no significant difference in age (p = 0.8), femur length (p = 0.2), pelvic width (p = 0.08), and knee width at the femoral condyles (p = 0.06), but fracture cases were shorter (p = 0.01), lighter (p = 0.0006), and smaller in most anthropometric girth dimensions (p < 0.04). Fracture case bone cross-sectional areas (p < 0.001), moments of inertia (p < 0.001), section moduli (p < 0.001), and widths (p < 0.001) as well as BMD (p < 0.03) were significantly smaller in the tibia and femur. After correcting for body weight differences, the tibia cross-sectional area (p = 0.03), section modulus (p = 0.05), and width (p = 0.03) remained significantly smaller in fracture subjects. We conclude that both small body weight and small diaphyseal dimensions relative to body weight are factors predisposing to the development of stress fractures in this population. These results suggest that bone structural geometry measurements derived from DXA data may provide a simple noninvasive methodology for assessing the risk of stress fracture.

Low levels of estradiol are associated with vertebral fractures in older men, but not women: the Rancho Bernardo Study.

This longitudinal study included 288 postmenopausal women without estrogen use (median age, 72 yr) and 352 men (median age, 66 yr). All were community-dwelling, ambulatory, and Caucasian. Blood for hormone assays (total and bioavailable estradiol and testosterone, estrone, androstenedione, dihydrotestosterone, dehydroepiandrosterone, and dehydroepiandrosterone sulfate) was obtained in 1984-1987, and vertebral fractures were diagnosed from lateral spine radiographs obtained in 1992-1996. At least one vertebral fracture was found in 21% of women and 8% of men. Among men, age-adjusted hormone levels differed by fracture status only for total (64.1 vs. 75.4 pmol/L, P = 0.012) and bioavailable (43.0 vs. 51.4 pmol/L, P = 0.008) estradiol. There was a graded association between higher concentrations of total and bioavailable estradiol and lower fracture prevalence (trend P<0.01 for both hormones). Men with total testosterone levels compatible with hypogonadism (<7 nmol/L) were not more likely to have vertebral fractures. In women, none of the measured sex hormones was associated with vertebral fractures. There was also no increased prevalence of fractures in women with estradiol levels below the assay sensitivity (<11 pmol/L). These data suggest that estrogen plays a critical role in the skeletal health of older men and confirm other studies showing no association of postmenopausal endogenous estrogen levels with vertebral fractures in older women.

Clinical studies with In-111 BLEDTA, a tumor-imaging conjugate of bleomycin with a bifunctional chelating agent.

Indium-111 BLEDTA, a bleomycin analog containing an EDTA group, was used for tumor imaging in 110 patients with cancer. Scans with In-111 BLEDTA agreed with biopsy results in 75 of 95 patients (79% accuracy). A positive scan was obtained in 71 of 88 patients with a positive biopsy (81% sensitivity). In 21 of 95 patients (22%), the scan revealed tumor sites that had not been detected. The main limitation of visualization was the size of the tumor (1.5--2.0 cm diameter was the smallest size seen). Background radioactivity in the liver, spleen, and bone marrow also made tumor detection in these areas more difficult. The cause of this background, and of false-positive uptake in sites of inflammation, is correlated with specific radiolabeling of polymorphonuclear leukocytes by In-111 BLEDTA. Means of eliminating this background are discussed.

Pattern of endogenous lectins of a human sarcoma (Ewing's sarcoma) reveals differences to human normal tissues and tumors of epithelial and germ cell origin.

A human sarcoma, Ewing's sarcoma, contains activities of endogenous lectins. Fractionation of salt and detergent extracts by affinity chromatography on columns with immobilized sugars or glycoproteins results in the pattern of endogenous lectins for alpha- and beta-galactosides, alpha-mannosyl- and alpha-fucosyl-moieties. Whereas some lectins are known from normal, non-malignant human tissues or from a human epithelial tumor or a human germ cell tumor, a Ca2+-independent alpha- and beta-galactoside-binding protein at apparent molecular weight of 58 kilodaltons has so far not been characterized from any human source. The patterns for the tumors and human normal tissues reveal various differences in comparison between each other. These differences, documented for the first human sarcoma, human tumors of different histogenetic lineage and normal tissues are a first step to a lectin-based diagnosis and therapy of certain human cancer types.

Quantitative assessment of distraction and angulation following long bone fracture.

A new technique for evaluating distraction and angulation of long bone fracture fragments is described and tested using a laboratory model. Advantages over conventional dual-projection radiography include quantitative information and independence from magnification and projectional differences between serial studies.

Dual-energy scanned projection radiography of osseous metastatic disease.

Dual-energy scanned projection radiography was used to evaluate eight patients with both lytic and blastic metastatic disease in the axial skeleton. The ability to selectively cancel obscuring soft-tissue structures from images resulted in improved conspicuity of involved sites, compared with conventional radiographic studies, despite greater quantum noise and lower inherent spatial resolution. Other desirable features of the technique include a projected format, image enhancement by contrast and brightness optimization, rapid data acquisition, convenient image storage and retrieval, and low radiation dose. Since the majority of osseous metastases involve axial sites, dual-energy scanned projection radiography may be a useful adjunctive modality in the management of oncology patients.

Coralline hydroxyapatite bone-graft substitutes in a canine metaphyseal defect model. Radiographic-histometric correlation.

Radiographic and histometric evaluation of a new form of bone-graft substitute derived from reef-building sea coral was performed in a canine metaphyseal defect model. Blocks of this material were implanted into the proximal tibial metaphyses of eight dogs, with radiographic densitometry and harvesting performed at two, four, six, and 12 months. Histometric analysis demonstrated progressive apposition of host compact bone at the margins and trabecular bone at the interior of the implants with time following surgery. Corrected transmission density determinations correlated significantly with degree of osseous ingrowth (R = -0.78), void volume fraction (R = 0.88), and postoperative interval (R = 0.88). These results support the successful early application of coralline hydroxyapatite bone-graft substitutes as an alternative to autogenous grafting in the clinical setting, and indicate that the course of incorporation into host bone can be noninvasively monitored using densitometric techniques.

Dual-energy projection radiography in the evaluation of femoral neck strength, density, and mineralization.

Two different dual-energy projection radiography techniques were utilized in an attempt to predict femoral neck strength, bone density, and bone mineral content in 19 pairs of cadaver specimens. Positive simple linear correlation was observed between dual-energy scanned projection measurements and dry density, ash fraction, cross-sectional cortical bone area and, to a lesser degree, force required for fracture, but not trabecular bone volume, failure time, or Singh trabecular grade. Dual-energy film radiography was found to be a less reliable indicator of femoral neck strength, density, and mineral content. Dual-energy scanned projection results related linearly to mineral-equivalent solution (K2HPO4) concentration, and demonstrated long-term reproducibility in repeated specimen studies. Correction factors derived to account for differences in femoral size and rotation were shown to be reliable over a moderate range of neck projections. Although bone mineral measurement at other sites may provide comparable or greater information concerning hip fracture risk, dual-energy scanned projection radiography appears to be a useful technique for assessment of bone density, mineral content, and strength in the femoral neck.

Coralline hydroxyapatite bone-graft substitutes in a canine diaphyseal defect model. Radiographic-histometric correlation.

Radiographic and histometric evaluation of a new form of bonegraft substitute derived from reef-building sea coral was performed in a canine diaphyseal defect model. Comparably sized blocks of this material and iliac crest autograft were placed into bilateral surgically created cortical windows in the distal radial diaphyses of 14 dogs. Representative graft specimens of both types underwent densitometric radiography and harvesting at 3, 6, 12, 24, and 48 months. Histometric analysis of implant specimens revealed satisfactory union and native osseous ingrowth at all time intervals. Graft specimens exhibited adequate union with scant host bone ingrowth at three months, but subsequent progressive appositional closure of cancellous spaces during the ensuing 45 months. Volume fraction and mean width of host bone remained stable in the implants but increased in the grafts due to neocortex formation. Stereologic distribution of bone was homogeneous in both implant and graft specimens, and no evidence for biodegradation of the former was observed. Corrected transmission density determinations accurately reflected these differences but correlated significantly with volume fractions and tissue widths of bone and soft tissue only in the autografts. These results support the successful early application of coralline hydroxyapatite bone graft substitutes as an alternative to autogenous grafting in the clinical setting and emphasize the potential role of noninvasive densitometric techniques in monitoring the incorporation of bone-graft materials.

Sternocostal joints. Anatomic, radiographic and pathologic features in adult cadavers.

Using radiographic-pathologic correlation, we studied the sternocostal joints derived from 27 consecutive cadavers and one additional cadaver with rheumatoid arthritis. Radiographic findings that were tabulated included joint space narrowing, sternal or costal osteophytes, articular calcification, vacuum phenomena, and the degree of ossification of the costal cartilages. The first sternocostal joint could be classified as either a synchondrosis or synostosis in every instance; however, a joint cavity lateral to the first sternocostal joint represented a normal variation and was seen radiographically in 10 specimens. The second sternocostal joint was synovial in type and intimately related to the manubriosternal joint; cavitation within this joint was present bilaterally in 36% of our specimens. Degenerative changes in the sternocostal articulations were characterized much more frequently by sternal osteophytes than by costal osteophytes or joint space narrowing. Calcification compatible with chondrocalcinosis was observed in two cadavers. Radiographic and pathologic evidence of synovial inflammation was evident in the sternocostal joints of the rheumatoid specimen.

Evolving stages of lipohemarthrosis of the knee. Sequential magnetic resonance imaging findings in cadavers with clinical correlation.

RATIONALE AND OBJECTIVES: Lipohemarthrosis, the presence of fat and blood in a joint cavity, exhibits several complex layers related to differences in specific component relaxation on magnetic resonance (MR) images. The authors investigated sequential changes in the appearance of lipohemarthrosis of the knee as demonstrated by MR imaging. METHODS: Sequential MR imaging over a 4-day period was performed on two cadaveric knees after intraarticular injection of blood from a volunteer and fat from a cadaveric tibia (50 mL of blood and 25 mL of fat in one knee and 15 mL of blood and 5 mL of fat in the other knee). The authors determined components in the joint based on MR signal behavior. Magnetic resonance imaging examinations of four patients with intracapsular fractures and lipohemarthroses of the knee were reviewed retrospectively. RESULTS: Sequential MR images of cadaveric knees showed serial changes representing progressive formation and lysis of blood clot. Several fluid-fluid levels (globules of fat at the interface between fat and blood) and entrapment of fat were early findings of lipohemarthrosis. Three different fluid levels appeared approximately 3 hours after injection of fresh blood and marrow fat. The 96-hour study demonstrated three distinct levels. CONCLUSIONS: Lipohemarthrosis demonstrates temporal changes on MR imaging related to stages of formation and lysis of blood clot.

Pharmacokinetics of indium-111 BLEDTA in man.

111In-BLEDTA is a bleomycin-containing radiopharmaceutical that has proven useful as a tumor imaging agent. Whole blood distribution and pharmacokinetic parameters were studied in nine cancer patients, and the results compared with previously reported studies using 57Co-bleomycin. In eight patients studied by bolus intravenous injection, 111In-BLEDTA had a beta half-life (t1/2 beta) of 1.3 hours, a terminal-phase half-life (t1/2) of 11.7 hours, a volume of distribution (Vd gamma) of 57.5L/m2, a total body clearance rate (C1b) of 52.8 ml/min/m2, a renal clearance rate (C1r) of 23.3 ml/min/m2, and a 24-hour urinary excretion of 38.1% total administered dose. 111In-BLEDTA and 57Co-bleomycin have similar C1bs but differing Vds. Polymorphonuclear cell uptake of 111In-BLEDTA may explain its shorter t1/2 beta and t1/2, as well as its lower C1r and 24-hour urinary excretion. While the biologic characteristics of 111In-BLEDTA contribute to a greater background activity than is observed in scans with 57Co-bleomycin, its superior physical properties render it clinically more desirable as a tumor-imaging radiopharmaceutical.

Detection of thoracolumbar vertebral body destruction with lateral spine radiography. Part I: Investigation in cadavers.

Despite few and inconclusive studies, radiography is generally believed to be insensitive for detection of osteolytic lesions of the spine. A more detailed investigation was undertaken to study the detectability of laboratory-produced osteolytic lesions in cadaveric thoracolumbar vertebral bodies using conventional lateral radiographs. The radiographs were presented to four radiologists in two sessions over a two month period. In the first session, the films were arranged in a composite of five vertebral bodies, T11 to L3 all from the same spine, in which one contained a lesion and the other four were normal. In the second session, each vertebral body film was presented individually. Area (Az) under the receiver-operating characteristic (ROC) curve was used to measure the performances of readers. Observer detection was similar in the two formats with Az ranging from 0.67 +/- 0.05 to 0.79 +/- 0.04 for the composite film arrangement and 0.57 +/- 0.08 to 0.85 +/- 0.10 for the films of individual vertebral bodies. Lesions were grouped into three relative size categories: 18% to 25%, 26% to 40%, and 41% to 60% of transverse vertebral body diameter. The mean increase in ROC area between the small and large lesions was 0.29 (P less than 0.04) for the composite films and 0.16 (P less than 0.05) for the individual films. In the composite study, all readers showed significant (P less than 0.05) increases in lesion detection in spines reflecting large increases (P less than 0.01) in bone mineral content.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of thoracolumbar vertebral body destruction with lateral spine radiography. Part II: Clinical investigation with computed tomography.

Conventional radiography in the lateral projection was used to evaluate 25 osteolytic lesions involving vertebral bodies of the thoracolumbar spine. Destruction was calculated as percentages of the maximum transverse diameter and volume of the vertebral body as measured by computed tomography (CT) and the effect of size of lesion on detection was evaluated. Areas (Az) under the receiver-operating characteristic (ROC) curves and the significance of differences were determined from the observations of four radiologists. The mean difference between areas under the ROC curve for lesions involving 32% to 60% of the transverse diameter and for larger lesions of 61% to 93% was 0.12 and significant (P less than 0.05). The effect of the presence of localized loss of vertebral body density, sclerotic bone tissue surrounding the lesion and cortical destruction was evaluated in a second session, in films with lesions the observers scored 4 (probably abnormal) or 5 (definitely abnormal). Cortical destruction was reported to be helpful for detection in 35% of lesions, sclerotic bone surrounding the lesions was helpful in 30%, and a qualitative local decrease in bone density was noted in all lesions. In comparison with the results obtained for the same four observers with experimentally produced lesions in our previous cadaveric study, the clinical lesions of comparable size were not as readily detected. The ROC area for the largest group of clinical lesions (61% to 93%, Az = 0.83 +/- 0.07) was not significantly different from that for a group of smaller cadaveric lesions (41% to 60%, Az = 0.83 +/- 0.05). The smaller clinical lesions (32% to 60%, Az = 0.71 +/- 0.08) were similar in detectability to the experimental lesions of relative diameter 26% to 40% (Az = 0.74 +/- 0.15). Caution should be exercised in the interpretation of conventional radiographs in the lateral projection if there is suspicion of vertebral body destruction.

The effect of intra-articular gadolinium-DTPA on synovial membrane and cartilage.

This investigation evaluated the potential effect of gadolinium (Gd)-DTPA-dimeglumine on synovial membrane and joint cartilage, using macroscopic, microscopic, and x-ray fluorescent spectroscopic techniques. Thirteen New Zealand white rabbits (26 knees) were used in this study, ten receiving 500 micromolar injections of Gd-DTPA-dimeglumine in their right knees; the remainder of the knees served as controls. One injected knee had minimal joint effusion and one had mild hyperemia. Microscopically four knees exhibited mild focal hyperplasia of the synovium, another three minimal focal mononuclear cell infiltration. X-ray fluorescent spectroscopy demonstrated no evidence of Gd-DTPA-dimeglumine in the synovium or articular cartilage. Neither macroscopic nor microscopic evaluation detected any Gd-DTPA-dimeglumine related effects. Gd-DTPA-dimeglumine was found to be safe for intra-articular injection in this animal model.

The high signal intensity meniscus of the knee. Magnetic resonance evaluation and in vivo correlation.

This study describes the different appearances of meniscal abnormalities on magnetic resonance (MR) images and correlates macroscopic and histologic findings. Twenty-three of 40 cadaveric menisci with MR signal abnormalities were examined macroscopically; five of the 23 were studied histologically. In addition, MR studies of seven patients (14 menisci) were examined and findings were correlated arthroscopically. Histologic analysis was performed on two of these menisci. The two major findings on MR images were: (1) abnormal, high, centrally located signal intensity within the meniscus and (2) disruption of the peripheral meniscal contour. Macroscopically evident meniscal degeneration correlated well with findings on MR images in all cases. Histologic abnormalities included microcyst formation and separation of collagen bundles. Four menisci with intact outer contour lines on MR images had macroscopically identifiable tears. In addition, two meniscal tears were appreciated only after intra-articular injection of gadolinium-DTPA. We conclude that MR imaging is superior to macroscopic examination as performed by arthroscopy or arthrotomy for the detection of degenerative meniscal lesions. The technique also accurately identifies meniscal tears, a capability that might be enhanced by prior intra-articular injection of MR contrast agents.

Perfluoroctylbromide as a contrast agent for computed tomographic imaging of septic and aseptic arthritis.

Perfluoroctylbromide (PFOB), a perfluorocarbon macrophage-labeling contrast agent, was applied to computed tomographic imaging of septic and aseptic arthritis models in rabbits. Marked enhancement of induced pyarthrosis was observed in both the knee and the sacroiliac joint. Moderate enhancement was noted in tetracycline-induced synovitis of the knee. Sterile synovitis of the sacroiliac joint and simple knee joint effusion showed no enhancement. These results suggest that PFOB is a useful contrast medium for the diagnosis of and distinction between septic and sterile arthritis.

Ventral sacroiliac ligament. Anatomic and pathologic considerations.

RATIONALE AND OBJECTIVES: The ventral sacroiliac ligament (VSL), which bridges the sacroiliac (SI) joint anteriorly, has been described as an important stabilizing structure of the joint, but no data exist regarding its assessment with routine and advanced imaging methods. The authors determine the imaging appearance of the normal and abnormal VSL using close anatomic-histologic-imaging correlation. METHODS: Eight and 10 cadaveric SI joints were examined with magnetic resonance imaging in axial and coronal planes, respectively; and in four computed tomography scanning in both planes was obtained. Anatomic sectioning with histologic correlation at levels corresponding to those of imaging planes was performed. Representative examples of diseases that produce abnormalities of the VSL and connective tissue about the SI joint were reviewed. RESULTS: Magnetic resonance images showed the VSL-anterior capsular complex as a hypointense, linear, or minimally curved structure of approximately 2 mm thickness traversing the SI joint anteriorly. The VSL could not be separated from the anterior joint capsule by imaging studies, but such differentiation by histology could be determined based upon the orientation of its collagen fibers. Any disease process that affects the ligament or the site of ligamentous attachment to bone produces characteristic imaging alterations.

Coralline hydroxyapatite bone graft substitutes. Evaluation of bone density with dual energy x-ray absorptiometry.

RATIONALE AND OBJECTIVES: The authors evaluate whether dual-energy x-ray absorptiometry (DXA) is a reliable method to determine the density of natural coralline hydroxyapatite (HA) blocks used as bone graft substitutes. METHODS: To evaluate the basic density of HA blocks from the same coral heads with and without titanium meshes, densitometry of 12 HA-500 blocks (genus Goniopora) and 12 HA-200 blocks (genus Porites) was performed. In addition, density measurements of 30 HA blocks (HA-500, n = 15; HA-200, n = 15) from different coral heads were obtained to assess if the originating coral head influences the basic density of blocks within one coral genera. To assess standard deviation serial measurements on eight coralline HA blocks, four with titanium meshes and four without were performed. In the ex vivo study, densitometry of 12 HA blocks (HA-500, n = 4; HA-200, n = 8) used as bone graft substitutes in the mandibles and craniums of adult mongrel dogs was performed. Densities were measured after bone ingrowth for 2 and 4 months, respectively. All measurements were obtained with a Lunar DPX with scan mode "slow 750" in the spine program with the regions-of-interests selected manually. Bone ingrowth was assessed by computer-assisted histomorphometry, which was considered the gold standard. Statistical analysis was performed to correlate the densities of plain HA blocks with and without meshes to the specific weights of the blocks. RESULTS: Significant positive correlation was found between the density of each HA block (both coral species) with and without meshes and the calculated specific weights. Densitometry values showed no significant differences depending on the originating coral heads. Standard deviation ranged between +/- 3.8% and +/- 4.1% (HA-500) and between +/- 3.0% and +/- 3.8% (HA-200). Hydroxyapatite-500 blocks showed marked increased densities between 15% and 34% after 4 months in three specimens in which bone ingrowth between 16.9% and 21.1% was revealed by histomorphometry; no increase of density was observed in one specimen, which presented only minimal bone ingrowth and signs of infection. Despite bone invasion between 12% and 25.8%, no increased densities were observed for HA-200 implants. CONCLUSIONS: Dual-energy x-ray absorptiometry is an accurate and reproducible modality to assess the densities of plain coralline HA blocks and to monitor bone ingrowth into coralline HA-500 but not into HA-200 block implants.