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Biomedical subjects

H S An

Publications and source records attributed to H S An.

101 records · Page 6Linked to original sources
PubMed1988

Reflex sympathetic dystrophy and cigarette smoking.

Although the cause of reflex sympathetic dystrophy (RSD) remains unknown, hyperactivity of the sympathetic nerves and secondary vasospasm may be pathogenic in this syndrome. A retrospective epidemiologic study of RSD was done on 53 in-patients from 1978-1985. Cigarette smoking was strikingly increased in patient frequency in RSD (68% versus 37% of hospitalized controls, p less than 0.0001). Eighty-seven percent of the patients had a history of trauma or surgery, and 38% had other associated diseases. Cigarette smoking is statistically linked to RSD and may be involved in its pathogenesis by enhancing sympathetic activity, vasoconstriction, or by some other unknown mechanism.

Adolescent↗
PubMed1988

Open scapulothoracic dissociation with intact neurovascular status in a child.

A case of open scapulothoracic dissociation with intact neurovascular status in an 8-year-old girl is reported. Scapulothoracic dissociation is a rare injury. Most cases present with significant soft tissue disruption in the shoulder region secondary to separation of the scapula from the thorax, and involve major vascular and brachial plexus injuries. This case report illustrates that an obvious roentgenographic scapulothoracic dissociation may be seen without any neurovascular deficit in a child. Successful treatment, with anatomical repair of the muscles and stabilization of the scapula, is described.

Amputation, Traumatic↗
PubMed1988

Osteolysis of the pubic bone simulating malignancy. A case report and review of literature.

A 78-year-old white female presented with groin pain of 3 months' duration. Radiographs revealed an osteolytic lesion in the pubic bone, simulating a malignancy or infection. A closed needle biopsy was performed and pathological findings were consistent with post-traumatic osteolysis, showing avascular necrotic tissues. A review of the literature found 16 previous cases presenting with groin pain and a radiographic lesion in the pubic bone that appeared malignant. All of the patients reported in the literature were postmenopausal women most with a recent history of trauma or increased physical activity. All of the lesions were benign and, when treated conservatively, usually resolved within 6 months.

Aged↗
PubMed1988

Scapulothoracic dissociation.

Scapulothoracic dissociation is a rare entity that consists of disruption of the scapulothoracic articulation. The mechanism of injury is probably traction caused by a blunt force to the shoulder girdle. This lesion is characterized by massive soft-tissue swelling of the shoulder; lateral displacement of the scapula, measured radiographically; an injury to bone (an acromioclavicular separation, a displaced fracture of the clavicle, or a sternoclavicular disruption); a severe neurovascular injury; and a variety of upper and lower-extremity fractures. We treated fifteen patients who had this lesion, most of whom had several associated injuries. Three patients died: two from exsanguination and one from a cardiac arrest. In most patients, the damaged artery was repaired and the brachial plexus was explored. All of the twelve patients who had a complete brachial-plexus injury were left with a flail upper extremity. Most patients refused amputation.

Acromioclavicular Joint↗
PubMed1987

Transient simultaneous sciatic and femoral nerve palsy secondary to iliacus and gluteal hematomas following heparinization for pulmonary embolus in a patient with posterior hip dislocation.

Sciatic nerve palsy as a result of a posterior hip dislocation has been reported in the literature. Femoral nerve palsy as a result of a iliacus hematoma has also been documented. However, a simultaneous sciatic and femoral nerve palsy occurring after heparinization for a pulmonary embolus in a patient with a posterior hip dislocation has not been reported. This combined nerve palsy was found in a 64-year-old white woman who had been involved in a motor vehicle accident and sustained a posterior hip dislocation. This patient subsequently had a pulmonary embolism, was heparinized, and then developed a large iliacus and gluteal hematoma, resulting in a simultaneous sciatic and femoral nerve palsy. Without treatment, the patient regained motor and sensory of the sciatic nerve in a few days, and a gradual improvement of function of her femoral nerve was evident over several months.

Female↗
PubMed1987

Heterotopic ossification and pseudoarthrosis in the shoulder following encephalitis. A case report and review of the literature.

Heterotopic bone formation, or myositis ossificans, is common, particularly following trauma, total hip arthroplasty, spinal cord injury, severe head injury, and long-term coma. Although the mechanism is unknown, the pathogenesis is assumed to depend on transformation of mesenchymal cells to bone forming cells in response to a variety of stimuli. The clinical findings, laboratory data, roentgenograms, and radionuclide studies are standard aids in the diagnosis of heterotopic ossification. The treatment usually consists of range-of-motion exercise, nonsteroidal antiinflammatory drugs, X-ray therapy, disodium etidronate (EHDP), and excisional surgery. Reported here is a rare case of periarticular heterotopic ossification in the shoulder of a 38-year-old woman following head injury and 13 months in a coma. The unusual feature was the development of a pseudoarthrosis within the heterotopic bone. The patient's shoulder became markedly stiff with the development of a heterotopic pseudoarthrosis. Excision of the heterotopic bone and pseudoarthrosis was performed to improve the range of motion. Clinical roentgenographic, radionuclide, and pathologic observations are presented on the formation of a synovial joint within the heterotopic bone.

Adult↗
PubMed1987

Essential cryoglobulinemia associated with intense and persistent synovitis of the knee.

Two patients with essential cryoglobulinemia, an immune complex disease, developed an intense, chronic, monoarticular knee synovitis. In each patient, synovial fluid findings (high white count and left shift) suggested a pyrogenic or crystalline etiology. A synovectomy was eventually performed in both patients to control their synovitis, which was refractory to medical management. The histologic and immunofluorescent synovial changes in the arthropathy of essential cryoglobulinemia, which was not previously been characterized, are marked by diffuse eosinophilic infiltration and edema. In both patients, synovial specimens suggested an immune complex process; immunofluorescent studies revealed immunoglobulin IgG in one patient, and IgG, IgA, and immune complexes (C1q) deposits in the other patients. Both patients, subsequently treated with D-penicillamine and chloroquine, or chloroquine alone, were followed for two years and had a slow but definite fall in their cryoglobulin levels, despite the persistence of monoarticular synovitis in one patient.

Adult↗
PubMedDate not supplied

The relationship between disc degeneration and flexibility of the lumbar spine.

BACKGROUND CONTEXT: A relationship between degenerative changes of the intervertebral disc and biomechanical functions of the lumbar spine has been suggested. However, the exact relationship between the grade of disc degeneration and the flexibility of the motion segment is not known. PURPOSE: To investigate the relationship between degenerative grades of the intervertebral disc and three-dimensional (3-D) biomechanical characteristics of the motion segment under multidirectional loading conditions. STUDY DESIGN/SETTING: A biomechanical and imaging study of human cadaveric spinal motion segments. METHODS: One hundred fourteen lumbar motion segments from T12-L1 to L5-S1 taken from 47 fresh cadaver spines (average age at death, 68 years; range, 39 to 87 years) were used in this study. The severity of degeneration (grades I to V according to Thomson's system) was determined using magnetic resonance (MR) images and cryomicrotome sections. Pure unconstrained moments with dead weights were applied to the motion segments in six load steps. The directions of loading included flexion, extension, right and left axial rotation, and right and left lateral bending. RESULTS: When the MR images were graded, 2 segments had grade I disc degeneration; 45, grade II; 20, grade III; 26, grade IV; and 21, grade V. When the cryomicrotome sections were graded, 14 segments had grade I disc degeneration; 31, grade II; 22, grade III; 26, grade IV; and 21, grade V. Segments from the upper lumbar levels (T12-L1 to L3-4) tended to have greater rotational movement in flexion, extension, and axial rotation with disc degeneration up to grade IV, whereas the motion decreased when the disc degenerated to grade V. In the lower lumbar spine at L4-5 and L5-S1, motion in axial rotation and lateral bending was increased in grade III. CONCLUSIONS: These results suggest that kinematic properties of the lumbar spine are related to disc degeneration. Greater motion generally was found with disc degeneration, particularly in grades III and IV, in which radial tears of the annulus fibrosus are found. Disc space collapse and osteophyte formation as found in grade V resulted in stabilization of the motion segments.

Adult↗
PubMedDate not supplied

MR contrast enhancement: an experimental study in postlaminectomy epidural fibrosis.

PURPOSE: To measure the effect of contrast medium dose, time elapsed since injection, and maturity of epidural scar tissue on the enhancement of scar tissue in MR imaging. METHODS: We imaged 12 beagle dogs with MR at 10 to 60 days after lumbar laminectomy, and at necropsy we obtained exactly correlating histologic sections. Contrast enhancement of scar tissue at 2, 15, 40, and 60 minutes after 0.1 and 0.3 mmol of paramagnetic contrast medium per kilogram was measured. Contrast enhancement was analyzed with respect to the dose of contrast medium, the time of imaging, and the maturity of scar tissue. RESULTS: Epidural scar tissue enhanced more intensely at 2 and at 15 minutes than at 40 or at 60 minutes. Consistently greater enhancement was observed with the dose of 0.3 mmol/kg than with the dose of 0.1 mmol/kg. Regions of loosely organized scar tissue enhanced less intensely and less quickly than did more organized scar tissue. CONCLUSION: Contrast enhancement in scar tissue can be heightened by increasing the dose of contrast medium from 0.1 to 0.3 mmol/kg and by obtaining images within 15 minutes of injection.

Animals↗