| 1. |
- Necking, Lars, et al.
(författare)
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Hand muscle pathology after long-term vibration exposure
- 2004
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Ingår i: J Hand Surg [Br]. - : SAGE Publications. - 0266-7681. ; 29:5, s. 431-7
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Tidskriftsartikel (refereegranskat)abstract
- The morphology of the abductor pollicis brevis muscle was studied in 20 patients suffering from hand-arm vibration syndrome. The main morphological changes observed were centrally located myonuclei and fibre type grouping (found in all 20 muscle biopsies), angulated muscle fibres (found in 19 biopsies), ring fibres and regenerating fibres (found in 18 biopsies) and fibrosis (found in 17 biopsies). The observed abnormalities are believed to reflect damage to both the muscle fibres and the motor nerve. The changes were related to different vibration exposure parameters. The number of fibres demonstrating centrally located nuclei correlated significantly with the cumulative vibration exposure, while the number of angulated fibres correlated significantly with the total vibration exposure time. This indicates that the vibrating tools may cause direct damage to muscle fibres as well as nerves.
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| 2. |
- Karlsson, Magnus K, et al.
(författare)
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Silicone rubber implants for arthrosis of the scaphotrapezial joint
- 1992
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Ingår i: Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery. - : Informa UK Limited. - 1651-2073 .- 0284-4311. ; 26:2, s. 173-176
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Tidskriftsartikel (refereegranskat)abstract
- Between 1980 and 1983, 10 patients received high performance silicone rubber condylar implants for the treatment of isolated degenerative changes of the scaphotrapezial joint. Early clinical and radiographic results (at a mean of 15 months) were excellent. Late follow up of these 10 together with a further 11 patients, however, showed migration of the implant and radiological signs of silicone particle synovitis in all but two. We no longer recommend this operation for treatment of isolated arthrosis of the scaphotrapezial joint.
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| 3. |
- Necking, Lars, et al.
(författare)
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Hand muscle weakness in long-term vibration exposure.
- 2002
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Ingår i: Journal of Hand Surgery (British Volume). - : SAGE Publications. - 0266-7681. ; 27:6, s. 520-525
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Tidskriftsartikel (refereegranskat)abstract
- Hand muscle strength was compared between workers regularly exposed to hand-held vibrating tools ( n = 81) and a non-exposed control group ( n = 45). Maximal voluntary strengths of hand grip, thumb pinch, thumb palmar abduction and index and little finger abduction were measured. The exposed workers had significantly weaker extrinsic (7%, P < 0.01) and intrinsic (19%, P < 0.0001) muscles than the controls. Reduced vibration perception was noted in nine vibration-exposed workers who presented with symptoms of hand muscle weakness ( P < 0.01). Cold intolerance following vibration exposure was found to precede sensorineural and vasospastic symptoms. We therefore postulate that cold intolerance may be a valuable marker for early detection of the adverse effects of vibration. This study emphasizes the need for tests of intrinsic muscle strength in order to evaluate the impairment of hand function observed in vibration-exposed workers.
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| 4. |
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| 5. |
- Necking, Lars
(författare)
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Vibration-induced muscle injury in the hand - experimental and clinical studies
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Exposure to vibration is known to cause vasospastic white fingers and/or sensorineural symtoms such as numbness and tingling in fingers and/or musculoskeletal disorders such as reduction in muscle force, fatigue and reduced endurance. Classifications for the vasospastic and sensorineural symptoms are established. The general purpose of this thesis was to test the hypothesis that vibration exposure causes muscle injury. In an experimental model, muscle biopsies from hind paws of rats demonstrated that short-term vibration exposure caused damage to the muscles directly exposed to vibration stimuli. Degenerative changes were observed after two and regenerative activity after five days of exposure. Morphological changes, indicated by increased percentage of fibres with internal myonuclei and increased muscle fibre cross-sectional area, were differentiated between muscle fibre types and also related to the physical characteristics of the vibration. The level of tissue displacement was demonstrated to be a crucial factor for the severity of muscle damage. Biopsies from a human hand muscle, the abductor pollicis brevis (APB) muscle, in 20 patients suffering from hand-arm vibration syndrome (HAVS), and thus subjected to long-term vibration exposure from hand-held vibrating tools, demonstrated several morphological changes reflecting damage to both muscle fibres and motor nerves. These findings can well explain the commonly observed loss of hand strength despite well-preserved muscle volume in these patients. In two populations, in total 102 vibration-exposed workers with and without the classified symptoms of HAVS, measurements of muscle strength in grip (mainly extrinsics) and in various hand muscles (intrinsics) revealed greater loss in intrinsic hand muscles than in extrinsic muscles. However, this greater loss of intrinsic muscle strength was not demonstrated to be determinant for subjective hand weakness but might be of importance for the impaired dexterity often noted. The greatest strength reduction was demonstrated for radial abduction of the index finger. Therefore, the first dorsal interosseus (IOD I) muscle is suggested as an important and reliable indicator of intrinsic muscle dysfunction and recommended to be tested in long-term vibration exposed individuals. A linear dose-response relationship between duration of exposure and morphological abnormalities as well as impairment of muscle function could not be demonstrated. The results from these studies clearly indicate the incompleteness of the present classifications for vibration-induced symptoms and emphasise the need to also include symptoms of muscular origin.
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