Biomedical subjects
Publications and source records attributed to M Nyska.
We present three cases of eosinophilic granuloma of the ilium in children. Imaging investigations (computed tomography and magnetic resonance imaging) did not elucidate the disease but rather revealed patterns more like malignant tumours than a benign condition. However, these investigations were of value in directing the surgeon to the correct site for biopsy.
Our understanding of mechanical controls on bone remodeling comes from studies of animals with surgically implanted strain gages, but in vivo strain measurements have been made in a single human only once. That study showed that strains in the human tibia during walking and running are well below the fracture threshold. However, strains have never been monitored in vivo during vigorous activity in people, even though prolonged strenuous activity may be responsible for the occurrence of stress fractures. We hypothesized that strains > 3000 microstrain could be produced on the human tibial midshaft during vigorous activity. Strains were measured on the tibiae of two subjects via implanted strain gauges under conditions similar to those experienced by Israeli infantry recruits. Principal compressive and shear strains were greatest for uphill and downhill zigzag running, reaching nearly 2000 microstrain in some cases, about three times higher than recorded during walking. Strain rates were highest during sprinting and downhill running, reaching 0.050/sec. These results show that strain is maintained below 2000 microstrain even under conditions of strenuous activity. Strain rates are higher than previously recorded in human studies, but well within the range reported for running animals.
Degenerative changes in the spine, specifically disc degeneration and facet arthrosis, and osteoporosis are conditions that primarily affect the elderly and may significantly impact the quality of life. The relationship between osteoporosis and degenerative changes in the hip joint has been studied, but their correlation in the spine is not entirely clear. Two hundred ninety-four subjects older than 50 years of age were retrospectively studied for the existence of lumbar spinal degeneration and osteoporosis through radiologic examination for 3 clinical manifestations: (1) disc degeneration, (2) facet joint arthrosis, and (3) lumbar osteoporosis. Peripheral osteoporosis in the distal radius of the nondominant hand was measured using a single-photon bone absorptiometer. Results indicated that subjects with severe osteoporosis in the distal radius also had severe degenerative changes in the discs and the facets; those with mild osteoporosis in the distal radius showed a tendency to have a lesser degree of degenerative changes than the subjects without osteoporosis.
The effect of walking with high-heel shoes on plantar foot pressure distribution was investigated. Ten normal women walking in shoes with low heels were compared to women walking in high-heel shoes. It was shown that high-heel shoes increased the load on the forefoot and relieved it on the hindfoot. The load passed toward the medial forefoot and the hallux. The lateral side of the forefoot showed a decrease in contact area, reduced forces, and peak pressures. The medial side of the forefoot had a higher force-time and pressure-time integral. It is suggested that these higher loads on the medial forefoot may aggravate symptoms in patients with hallux valgus deformity.
The study was conducted to test the hypothesis that alterations in shoe gear can affect tibial strains in the human during dynamic loading. Rosette strain gauges were mounted on the medial border of the mid-diaphysis in two human subjects with a new strain gauge bonding technique using methyl methacrylate. Strain measurements were made at this site, the most frequent location for stress fractures in the Israeli Army during treadmill walking and free running while wearing various sport shoes (Rockport ProWalkers and New Balance NBX 900) and army boots (light Israeli infantry, double layered sole Israeli infantry, and Zohar infantry boots). Data were analyzed for only one of the subjects because strain gauge bonding was found to be inadequate at the time of surgical removal in the other subject. No single shoe lowered both the principal tibial compression and tensile strains, and the shear strains. The Zohar boot had the lowest principal compression strains during treadmill walking and mobile running, despite its relatively higher weight and sole durometry.
To test in vivo the effect of previously observed inhibition of collagen type I transcription by the plant alkaloid Halofuginone, deep flexor tendons of 12 chickens were severed and sutured, and Halofuginone was applied topically at the site of surgery. Intact tendons, and severed but untreated tendons served as controls. The effect of the treatment was assessed by histological, biochemical, and biomechanical examinations of the operated and intact tendons three weeks after surgery. The results indicated an almost complete absence of fibrous peritendinous adhesions in the histologic sections of the Halofuginone treated tendons. There was a statistically significant decrease in collagen contents of and in both force and energy required to pull out the Halofuginone treated tendons from their sheath, relative to the untreated controls. Halofuginone had no effect on the cellularity of the healing tissue. We conclude that Halofuginone is a potent inhibitor of fibrous peritendinous adhesions with potentially important clinical applications.
The bare foot plantar pressures were compared to in-shoe pressure measurements in 11 normal male volunteers using the EMED system. Shoes diminished pressures and forces in most areas under the foot except the medial forefoot. The hallux showed less force, a smaller contact area and a reduced contact time. Therefore a shoe can interfere with the toe-off mechanism. There was no difference between various types of shoes with rubber and leather soles. Heavier subjects tended to put less weight on the medial forefoot.
In exercises involving running, muscle power and gravitational forces act together to affect bone mass in accordance with Wolff's law. However, the direct effect of muscle activity on bones in non-weight-bearing activities, such as swimming, has not been explored. Previous data indicate that swimming exerts a positive effect on bone growth and development in young rats. We performed a histomorphometric study on the effect of swimming on the growth plate and subepiphyseal area of young adult rats. The experiments were carried out on 28 12-week-old albino Sabra rats. One group of 14 rats was trained to swim 1 hour/day, 5 days a week, for 12 weeks. Another group of 14 rats served as controls. The proximal femur and humerus of each animal were examined histomorphometrically. There was an increase in the subepiphyseal cancellous bone trabecullae of the femur. In the growth plate there was an increase in the number of column cells and proliferative cells. These changes were more pronounced in the femur than the humerus. We conclude that swimming induces an increase in subepiphyseal cancellous bone in young adult rats by enhancing growth plate activity.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Four children aged 9 months, 11 months, 1 year, and 1 year 4 months, respectively, presented to the emergency room with an acute tender swelling of the sternum or sternocostal cartilage. Three of these resolved spontaneously within a few weeks of presentation, and in one curettage was carried out. We were unable to find any other references in the literature of this condition occurring in infants. Acute swelling of the chest wall frequently is due to neoplastic or infectious disease, and culture of aspirated material and possibly biopsy has been recommended in all cases. Our experience suggests that this may not always be necessary.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Hip synovitis plays a part in many rheumatic diseases. In the young adult acute arthritis may be due to reaction to trauma, infection or gout. Although transient synovitis of the hip is a well-known phenomena in children the condition is not well-documented in adults. We present 10 young adults with idiopathic transient synovitis of hip who had attended the Soroka Medical Centre between 1986 and 1990.
We reviewed the ultrasound findings in 59 children suspected of having bone infection. Twenty-nine were eventually proved to have acute haematogenous osteomyelitis and 26 of these showed characteristic ultrasound findings. Such changes were rare in 30 patients with other clinically similar conditions. Ultrasound examination was also able to detect the presence of subperiosteal pus and thus indicate the need for surgical treatment.
Explore the source record for details and available documents.
Chronic ankle instability is a common complication of ankle sprain. The clinical assessment of ankle instability is usually incomplete and difficult to interpret. Recently, more attention has been paid to the value of the anterior drawer test of the ankle. We assessed the accuracy of a modification of the anterior drawer test, comparing it with radiological stress view of the ankle in 25 patients with recurrent ankle sprain. The radiological examinations were performed by a TELOS instrument and included lateral and anteroposterior stress views. We found that the modified anterior drawer test correlated with the posterior opening of the tibiotalar joint and with the lateral tilt of the talus. We conclude that a slightly positive modified anterior drawer test may indicate injury to the anterior talofibular ligament. A significant movement of the ankle elicited by the modified anterior drawer test may indicate combined injury to anterior talofibular and calcaneofibular ligaments.
Explore the source record for details and available documents.