Estimating lumbar bone mineral density from routine radiographs of the lumbar spine.

To evaluate the information content of lateral lumbar films with respect to bone mineral content, we compared reading criteria with values obtained by quantitative computed tomography (CT) of L1 at baseline and after 5 years. The highest correlations with mineral content were found for the criteria "overall assessment of the vertebra", "vertebral bone density versus soft tissue", and "amount of trabeculations". These three reading criteria yielded higher correlations with CT scores in subjects with lower body mass index. Changes in mineral content over the 5-year period could not be read adequately, the average difference representing only a loss of about 10% in the study subjects. We conclude that a rough estimate of bone density can be obtained from lateral radiographs which, in the presence of eventual risk factors for osteoporosis, may serve as an additional indication to timely bone densitometry with methods which allow precise short-term follow-up measurements.

Rheumatologic and skeletal changes in acromegaly.

The anabolic functions of growth hormone (GH) and insulin-like growth factor-I (IGF-I) in cartilage and bone metabolism are important in the normal physiology of these tissues. The effects of chronic elevation of GH and IGF-I levels on bony structures produce the typical physical changes associated with acromegaly, whereas the effects on cartilage result in arthropathy, which is usually degenerative. This article presents an overview of the physiologic roles of GH and IGF-I in cartilage and bone metabolism, the clinical features of the degenerative arthropathy and other rheumatologic syndromes associated with acromegaly, effects of acromegaly on bone and mineral metabolism, and an unusual bone disease that is occasionally associated with acromegaly, the McCune-Albright syndrome.

MR imaging of the knee in acute rheumatoid arthritis: synovial uptake of gadolinium-DOTA.

In patients with rheumatoid arthritis, the presence of acute synovial inflammation is an indication of the activity of the disease. It is an important finding because it often influences therapeutic decisions. However, acute synovitis may be difficult to detect by clinical examination, especially if a joint effusion also is present. As gadolinium tetra-azacyclododecane tetraacetic acid (Gd-DOTA) can be expected to accumulate in areas of acute inflammation, we studied the value of Gd-DOTA-enhanced MR to determine the presence of acute synovitis. Nine patients with current knee symptoms underwent MR examination of the knee. Short and long TR/TE MR images were obtained with a 0.3-T magnet before and immediately after IV administration of Gd-DOTA. A 15-min delayed short TR/TE image also was obtained. Of eight patients with moderate to severe clinical evidence of acute synovitis, six had marked increase and two had moderate increase in signal intensity from synovial tissue on the short TR/TE image obtained immediately after administration of contrast material. In the ninth patient, who had minimal synovitis clinically, the signal from the synovium did not change after administration of contrast material. No difference was seen between the enhancement pattern on the immediate and the 15-min delayed images. These results suggest that Gd-DOTA is taken up by inflamed synovium and that Gd-DOTA-enhanced MR scans may be useful in detecting acute synovitis in patients with rheumatoid arthritis.

Insufficiency fracture of the sternum caused by osteopenia: plain film findings in seven patients.

Sternal insufficiency fractures, whether nonbuckling (displaced or nondisplaced) or buckling, are rare and have been described in elderly osteopenic patients with accentuated kyphosis of the thoracic spine. We retrospectively analyzed the radiographs and clinical records in seven osteopenic patients with sternal insufficiency fractures and correlated the type of insufficiency fracture with the presence and degree of dorsal kyphosis, as well as the presence of chest pain, soft-tissue mass, and osteolysis. We found that displaced or nondisplaced nonbuckling fractures (five patients) may be associated with chest pain localized to the sternum (three patients), and may be present with (three patients) or without (two patients) associated thoracic kyphosis. This type of insufficiency fracture also may be accompanied by a soft-tissue mass and osteolysis (three patients), findings simulating pathologic fractures. All buckling insufficiency fractures (two patients) were associated with thoracic kyphosis and were asymptomatic. Our findings suggest that sternal insufficiency fractures may occur with or without exaggerated dorsal kyphosis. The fractures are an uncommon complication of osteopenia and may resemble pathologic fractures when osteolysis and soft-tissue swelling are present.

Spontaneous osteonecrosis of the knee: value of MR imaging in determining prognosis.

Sixteen patients with early and late stages of spontaneous osteonecrosis of the knee were studied to evaluate if MR imaging can be used to determine the prognosis of the disease. All patients had sequential conventional radiographs and clinical examinations, one or more 99mTc-methylene diphosphonate bone scintigrams, and an MR examination. The duration of the disease at the time of the MR examination ranged from 1 to 58 months (mean, 18 months). A relationship was identified between the pattern of bone marrow alteration noted on long TR/TE MR sequences and the scintigraphic stage and clinical course of the disease. The dimensions of the osteonecrotic region could be identified as well or better on the short TR/TE MR images than on the radiographs in all patients. MR imaging also afforded evaluation of the hyaline cartilage overlying the osteonecrotic lesion, revealing secondary osteoarthrosis in seven patients. We conclude that MR imaging in patients with spontaneous osteonecrosis of the knee may provide information of value for determining the prognosis of the disease.

Isolated dislocation of the tarsal navicular: a case report.

Isolated dislocation of the tarsal navicular is a rare injury that is not mentioned in standard orthopedic textbooks and described only once in the English literature. Because of the rarity of this condition, the best means of treatment has not been established. A patient with this unusual dislocation was recently diagnosed and treated. Open reduction was eventually required, which was followed by the development of ischemic necrosis of the navicular.

Neuroarthropathy associated with chronic alcoholism.

Neuroarthropathy involving the feet is seen most commonly in patients with diabetes mellitus. Chronic alcoholism has been implicated as a cause of neuroarthropathy, but many alcoholics have coexistent diabetes mellitus, which may not be detected by measuring blood glucose levels alone. We report five chronic alcoholic patients with neuroarthropathic alterations of the feet in whom coexistent diabetes mellitus was excluded by using laboratory methods that are more sensitive than those employed in previously reported series of alcoholic neuroarthropathy. The radiographic features of neuroarthropathy in our five cases consisted of hypertrophic changes at the tarsal joints in four, bony fragmentation at the tarsal and metatarsal regions in three, fracture dislocation at the tarsometatarsal joint in two, and multiple pathologic fractures in one. We conclude that alcoholism can result in neuroarthropathy in the absence of diabetes mellitus.

Rheumatoid arthritis: similarity of radiographic abnormalities in men and women.

To test the hypothesis that there are significant differences in the radiographic appearance of rheumatoid arthritis between men and women, the authors blindly evaluated bilateral hand and wrist radiographs in 32 men with definite rheumatoid arthritis and 32 age- and disease duration-matched women (mean age, 56.4 years; mean disease duration, 10.5 years). Radiographically, disease distribution and severity were identical in these matched groups. Superimposed osteoarthritis was frequent in both groups and related to age. Ill-defined bone proliferation was present in 13 of 64 hands in both groups. Cystic changes and well-defined erosions were present in 12 of 64 male hands and six of 64 female hands, but this difference was not statistically significant. In women, presence of cysts and bone proliferation was related to disease duration, whereas men exhibited these atypical features independent of disease duration. There was no statistically significant difference in the frequencies of typical and atypical features of rheumatoid arthritis between the two sexes, and the authors postulate that previously reported differences relate to patient selection and lack of adequate matching.

Patterns of femoral head migration in osteoarthritis of the hip: a reappraisal with CT and pathologic correlation.

Although medial, superior, and axial patterns of migration of the femoral head in osteoarthritis of the hip have been well described, it is not clear what anatomic and biomechanical factors determine the direction of migration. The authors studied 22 patients with bilateral (11 patients) or unilateral (11 patients) osteoarthritis by means of conventional radiography and computed tomography (CT) to define any relationships between migration in the coronal plane and that in the transverse plane and to determine whether femoral anteversion, acetabular anteversion, femoral neck-shaft angle, or acetabular inclination were related to particular migration patterns. Anterior migration was evident in 14 of the 19 hips with a superior migration pattern, whereas posterior migration was present in five of the seven hips with a medial migration pattern. In the remainder of cases, no migration in the transverse plane was present. Femoral anteversion as determined with CT, femoral neck-shaft angle, angle of acetabular inclination, and acetabular anteversion angle in this relatively small sample were all found to be within normal limits and appeared to have no influence on the occurrence of a specific pattern of femoral head migration.

Carpal alterations in adult-onset Still disease, juvenile chronic arthritis, and adult-onset rheumatoid arthritis: comparative study.

A specific pattern of pericapitate involvement of the wrist has been described in the rheumatologic literature as characteristic of adult-onset Still disease (AOSD), a relatively rare disorder that is often diagnosed by exclusion after extensive and frequently invasive tests. To evaluate the potential diagnostic value of carpal radiography in suspected cases of AOSD, a retrospective blinded analysis of 48 patients (16 each with AOSD, juvenile chronic arthritis, and adult-onset rheumatoid arthritis) was performed. Pericapitate articular alterations without radiocarpal involvement were found to be distinctly unusual among patients with rheumatoid arthritis but frequent in the setting of AOSD. In juvenile chronic arthritis severe pericapitate involvement also occurs frequently but is more likely to be associated with interosseous fusion and severe pancompartmental disease.

Symptomatic intraspinal synovial cysts: opacification and treatment by percutaneous injection.

Intraspinal synovial cysts are usually located in the lower lumbar spine in association with osteoarthritis of the facet joints, and they are most accurately diagnosed by using CT. Surgical removal of intraspinal synovial cysts implicated in the development of radiculopathy has resulted in symptomatic relief. A nonoperative method of treatment consists of CT-guided needle placement into the facet joint adjacent to the cyst, followed by injection of contrast material to show communication between the joint and the cyst and injection of corticosteroids. Three outpatients were treated in this fashion without complications. Complete relief of symptoms was achieved in two cases and partial relief was achieved in one. Follow-up CT scans performed 2 months after the procedure showed no change in the size of the cysts in two of the patients. A 6-month follow-up CT scan in the third patient, however, showed significant improvement in cyst size. These preliminary results suggest that this procedure is an alternative to surgical management of intraspinal synovial cysts.

Patterns of paravertebral ossification in the prehistoric saber-toothed cat.

In cases of paravertebral ossification in humans, the radiographic characteristics usually lead to a specific diagnosis. Similar manifestations are sometimes described in other species. We applied knowledge of the radiographic appearance of spinal alterations in modern humans to the evaluation of 48 fused thoracic and lumbar fossilized spine specimens from the prehistoric saber-toothed cat (Smilodon californicus), in which prominent paravertebral ossification is frequently found. Inspection, conventional radiography, and, in some cases, CT and fluoride analyses were performed. The spinal alterations in the saber-toothed cat, which previously were believed to be caused primarily by trauma, showed characteristics of three major pathologic processes: trauma, diffuse idiopathic skeletal hyperostosis, and inflammatory disease of a type similar to ankylosing spondylitis. The last two categories have rarely been diagnosed in species other than humans. The results suggest that diffuse idiopathic skeletal hyperostosis and inflammatory spondyloarthropathy are diseases that occurred in prehistoric times and are not confined to the human species.

Enteropathic arthropathies.

Musculoskeletal disease occurs in association with inflammatory bowel disorders including Crohn's disease and ulcerative colitis, as well as with Whipple's disease; with enteritis caused by Salmonella, Shigella, and Yersinia; and also following intestinal bypass surgery. Extraintestinal causes of musculoskeletal alterations include Laennec's and biliary cirrhosis and pancreatitis. Three types of musculoskeletal abnormalities are recognized in patients with inflammatory bowel diseases: peripheral joint arthritis, sacroiliitis and spondylitis identical to ankylosing spondylitis, and rarely, miscellaneous changes such as digital clubbing and hypertrophic osteoarthropathy.