Fracture epidemiology and control in a developmental center.
During 3.5 years, 182 fractures occurred among 994 residents of a developmental center. The fracture rate was 5.2 per 100 person-years (1.7 times greater than the rate in the US population). Fracture rate was significantly greater in residents with: epilepsy, older age, male gender, white race, independent ambulation, osteoporosis, and residence in intermediate care (versus skilled nursing) units; it was not affected by severity of mental retardation. Hand and foot bones were fractured in 58% of cases. Femur fracture occurred in 13 cases (7%). Fracture was caused by a fall in 41 cases (23%); its cause was indeterminable in 105 cases (58%). Fractures, occurring without significant injury, may be an important cause of preventable disability in this population. Control measures are suggested. (+info)
Sensory processing in Parkinson's and Huntington's disease: investigations with 3D H(2)(15)O-PET.
There is conjoining experimental and clinical evidence supporting a fundamental role of the basal ganglia as a sensory analyser engaged in central somatosensory control. This study was aimed at investigating the functional anatomy of sensory processing in two clinical conditions characterized by basal ganglia dysfunction, i.e. Parkinson's and Huntington's disease. Based on previously recorded data of somatosensory evoked potentials, we expected deficient sensory-evoked activation in cortical areas that receive modulatory somatosensory input via the basal ganglia. Eight Parkinson's disease patients, eight Huntington's disease patients and eight healthy controls underwent repetitive H(2)(15)O-PET activation scans during two experimental conditions in random order: (i) continuous unilateral high-frequency vibratory stimulation applied to the immobilized metacarpal joint of the index finger and (ii) rest (no vibratory stimulus). In the control cohort, the activation pattern was lateralized to the side opposite to stimulus presentation, including cortical [primary sensory cortex (S1); secondary sensory cortex (S2)] and subcortical (globus pallidus, ventrolateral thalamus) regional cerebral blood flow (rCBF) increases (P < 0.001). Between-group comparisons (P < 0.01) of vibration-induced rCBF changes between patients and controls revealed differences in central sensory processing: (i) in Parkinson's disease, decreased activation of contralateral sensorimotor (S1/M1) and lateral premotor cortex, contralateral S2, contralateral posterior cingulate, bilateral prefrontal cortex (Brodmann area 10) and contralateral basal ganglia; (ii) in Huntington's disease, decreased activation of contralateral S2, parietal areas 39 and 40, and lingual gyrus, bilateral prefrontal cortex (Brodmann areas 8, 9, 10 and 44), S1 (trend only) and contralateral basal ganglia; (iii) in both clinical conditions relative enhanced activation of ipsilateral sensory cortical areas, notably caudal S1, S2 and insular cortex. Our data show that Parkinson's disease and Huntington's disease, beyond well-established deficits in central motor control, are characterized by abnormal cortical and subcortical activation on passive sensory stimulation. Furthermore, the finding that activation increases in ipsilateral sensory cortical areas may be interpreted as an indication of either altered central focusing and gating of sensory impulses, or enhanced compensatory recruitment of associative sensory areas in the presence of basal ganglia dysfunction. Altered sensory processing is thought to contribute to pertinent motor deficits in both conditions. (+info)
Comparative anatomy of the radial sesamoid bone in the polar bear (Ursus maritimus), the brown bear (Ursus arctos) and the giant panda (Ailuropoda melanoleuca).
Since we have clarified the manipulation mechanism using the radial sesamoid (RS) in the giant panda (Ailuropoda melanoleuca), our aim in this study is to examine the position, shape and function of the RS morphologically, and to observe the attachment to the RS of the M. abductor pollicis longus and the M. opponens pollicis in the other Ursidae species. So, we focused on the carpus and manus of the polar bear (Ursus maritimus) and the brown bear (Ursus arctos) in this study. The RS was tightly articulated to the radial carpal, and could not adduct-abduct independently of the radial carpal. The M. abductor pollicis longus tendon and the M. opponens pollicis belly were attached to the RS, independently. In the polar bear, the deep concave and the flat surface were confirmed in attachment area for these two muscles. The morphological relationship between the RS and the M. abductor pollicis longus and the M. opponens pollicis in the two species of bears were essentially consistent with that in the giant panda. It also demonstrated that the manipulation mechanism of the giant panda has been completely based on the functional relationship between the small RS, and the M. abductor pollicis longus and the M. opponens pollicis in Ursidae species. (+info)
Influence of multiple injections of vitamin E on intramuscular collagen and bone characteristics in suckling lambs.
We studied the influence of vitamin E on intramuscular collagen characteristics and on metacarpal growth plate evolution in suckling lambs. Twenty-four 5-d-old Ile de France suckling male lambs were divided into four equal weight groups, and weekly i.m. injections of DL-alpha-tocopheryl acetate (Control group, 0 IU; Group 1, 625 IU; Group 2, 1,000 IU; and Group 3, 1,500 IU) were given until the lambs were 33 d old. Blood samples were withdrawn for plasma alpha-tocopherol, cholesterol, and triglyceride analyses when the lambs were slaughtered at 40 d of age. Hot carcass weight, metacarpal and metatarsal bone characteristics, and metacarpal growth plate width were measured. After 24 h at 2 to 4 degrees C, semitendinosus muscles were removed for intramuscular collagen analyses. Weight was not influenced by treatment, but lambs in Group 1 had a higher (P < .01) intramuscular collagen content than the other groups. A positive quadratic correlation was found between total collagen and vitamin E doses (r = .511; P < .05). Amount and percentage of soluble collagen increased in muscles of all three vitamin E-treated groups compared with the control group. However, hydroxylysyl pyridinoline concentration decreased with vitamin E injection, but the difference compared to control lambs was only significant for the group injected with 1,000 IU. Amount of soluble collagen was strongly correlated to total collagen concentration (r = .879; P < .0001). It was also related to the alpha-tocopherol/(cholesterol + triglycerides) ratio in plasma (r = .431; P < .04). However, the correlation between soluble collagen percentage and alpha-tocopherol concentration in plasma was not significant (r = .369; P < .08). Bone length, weight, and diameter did not change, but the thickness of metacarpal growth plate increased as the DL-alpha-tocopheryl acetate dose increased; in Groups 2 and 3, the growth plate was significantly wider than in Group 1 and the controls. Growth plate width correlated with alpha-tocopherol/(cholesterol + triglycerides) ratio in plasma (r = .481; P < .02). (+info)
Can some physical therapy and manual techniques generate potentially osteogenic levels of strain within mammalian bone?
BACKGROUND AND PURPOSE: Although physical therapy techniques are used to alleviate pain and stiffness in joint injuries, whether these methods are capable of affecting bone is unknown. For example, can these techniques potentially influence bone formation or resorption? To begin exploring this possibility, this study investigated the ability of 4 manual techniques to generate levels of compressive strains that presumably can stimulate bone metabolism. SUBJECTS: Six 3,4 metacarpals from three 3-year-old Merino ewes were used. METHODS: A rosette strain gauge was implanted onto the dorsomedial cortex of each ovine 3,4 metacarpal. Four different manual procedures were applied on 2 occasions on each metacarpal in vivo and ex vivo. Mean peak principal compressive strains were calculated for each technique. RESULTS: Levered bending produced greater mean peak compressive strains than almost all other manual procedures tested in vivo or ex vivo. CONCLUSION AND DISCUSSION: Manual levered bending created levels of compressive strain similar in magnitude to those created by mechanical devices used in previous animal experiments to induce new bone formation (osteogenesis). This animal model appears to be suitable for investigating the effects of manually applied procedures on bone and may establish whether manual techniques can stimulate bone formation. (+info)
Safety of the limited open technique of bone-transfixing threaded-pin placement for external fixation of distal radial fractures: a cadaver study.
OBJECTIVE: To examine the safety of threaded-pin placement for fixation of distal radial fractures using a limited open approach. DESIGN: A cadaver study. METHODS: Four-millimetre Schanz threaded pins were inserted into the radius and 3-mm screw pins into the second metacarpal of 20 cadaver arms. Each threaded pin was inserted in the dorsoradial oblique plane through a limited open, 5- to 10-mm longitudinal incision. Open exploration of the threaded-pin sites was then carried out. OUTCOME MEASURES: Injury to nerves, muscles and tendons and the proximity of these structures to the threaded pins. RESULTS: There were no injuries to the extensor tendons, superficial radial or lateral antebrachial nerves of the forearm, or to the soft tissues overlying the metacarpal. The lateral antebrachial nerve was the closest nerve to the radial pins and a branch of the superficial radial nerve was closest to the metacarpal pins. The superficial radial nerve was not close to the radial pins. CONCLUSION: Limited open threaded-pin fixation of distal radial fractures in the dorsolateral plane appears to be safe. (+info)
Correlation of hand bone mineral density with the metacarpal cortical index and carpo:metacarpal ratio in patients with rheumatoid arthritis.
This study proposed an assessment of the correlation of hand bone mineral density measured by dual energy x-ray absorbtiometry (DXA) with the carpo:metacarpal (C:MC) ratio and metacarpal cortical index (CI) in patients with rheumatoid arthritis (RA). The correlation of total hand BMD, CI and C:MC ratio with BMD at other sites, the Health Assessment Questionnaire (HAQ) and Larsen scores were also examined. The hand and axial BMD of 30 female patients were also compared with 29 age-matched healthy female controls. Total hand BMD values of patients were significantly lower than the control group. There was no significant difference between groups in axial measurements. CI correlated moderately with the second metacap (II.MC) midshaft and total hand BMD. The C:MC ratio correlated with II.MC midshaft and total hand BMD. Total hand BMD correlated moderately with the AP spine (L2-L4) and femoral neck BMD. Larsen scores showed weak negative correlation with II.MC midshaft BMD and CI. Grip strength correlated weakly only with total hand BMD. The results indicated that CI may reflect cortical bone mass of the hand accurately and did not predict bone density of the spine or hip in patients with RA. The C:MC ratio is a useful method for evaluating progression of wrist involvement and may be related to the loss of hand bone mineral density associated with disease process. (+info)
Extra-abdominal desmoid tumor of the hand: a case report and review of the literature.
Extra-abdominal desmoid tumor of the hand is rare and only 10 cases have been described in the literature. We present a 14-year-old boy with a recurrent extra-abdominal desmoid tumor in the dorsal site of the right hand. MR image demonstrated the tumor in the third dorsal interosseous muscle, and adhered to the radial side of the forth metacarpal bone. The lesion revealed iso-signal intensity on T1-weighted images and high intensity on T2. We performed a marginal excision. Histological examination of the tumor showed proliferation of the fibroblastic cells with abundant collagen bundles. He developed local recurrence for the third time. The size of the third recurrent tumor has not been changed for 2 years and 3 months. Therefore, we have not performed any additional surgery. Since extensive resection markedly diminishes the function of the hand, we consider that a marginal surgical margin is acceptable for the quality of daily life of patients with a desmoid tumor of the hand. (+info)