ISSN:0736-0266    

DOI:10.1002/jor.1100010201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractA constant direct current cathode was employed in the medullary canal of the rabbit tibia to investigate electrical osteogenesis at low current levels. Currents of 0.015 or 0.075 μA were delivered to the bone and the biological response was compared with contralateral controls receiving 20 μA. This investigation was performed to determine if electrical osteogenesis occurs at current levels below the previously studied range of 1–100 μA with stainless steel electrodes. New bone formed by 0.015 μA cathodes was statistically comparable with that found around inactive cathodes from an earlier pertinent study. The osteogenic response to 0.075 μA cathodes was significantly elevated above that to inactive ones, thus substantiating electrical osteogenesis for currents below 1 μA. However, it is evident that this does not demonstrate a further stimulatory range but that currents near 0.075 μA probably approach the lower significant limit for electrically induced bone growth with stainless steel el

ISSN:0736-0266    

DOI:10.1002/jor.1100010202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThere has been clinical concern about the gray discoloration in synovial tissue adjacent to carbon‐reinforced polyethylene total joint implants. To evaluate the pathologic response of the synovium to this material, synovial specimens from 11 total ankle cases with carbon‐reinforced tibial components and two synovial specimens from cases with standard polyethylene tibial components were studied by gross and histologic techniques. Polyethylene debris was found to produce a significant synovial reaction with histiocytes and foreign body giant cells. This was found in both the carbon‐reinforced cases and in those cases without carbon‐reinforced components. This reaction is also seen in revisions of total hips and total knees in which standard polyethylene components have been implanted. In contrast with this, carbon particles produced only a minimal reaction in the synovial tissue. Carbon appears to be an extremely benign implant material, and synovial discoloration from shed carbon fibrils does not appear to present a significant clinical

ISSN:0736-0266    

DOI:10.1002/jor.1100010203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe timing and molecular profile of cartilage destruction inEscherichia coliandStaphylococcus aureusinfectious arthritis and killedMycobacterium butyricumadjuvant arthritis are presented. Infectious arthritis was studied for 3 weeks; cartilage samples were analyzed at 2, 10, and 21 days. At 48 h postinfection, glycosaminoglycan content was reduced by 20% (p<0.05) inE. coliinfected knees and by 42% (p<0.05) in tibial plateau cartilage ofS. aureusinfected knees. By the 3rd week of infection, glycosaminoglycan losses amounted to as much as 73% (p<0.005). In comparison, collagen losses were not significant prior to the 3rd week of infection, at which time 42% (p<0.05) was lost. Adjuvant arthritic tibial plateau cartilage was examined at 1, 3 and 12 weeks. Glycosaminoglycans decreased by 42% the 1st week, plateauing at 62% by the 3rd and 12th weeks. Collagen degradation began at 3 weeks (28% loss, p<0.10) and by the 12th week was reduced by 49% (p<0.005). Analysis of the individual species of glycosaminoglycan showed a parallel loss of chondroitin sulfate and keratan sulfate. Fractionation of glycosaminoglycans with respect to size produced no evidence of shortened chains in cartilage from infected joints. Hyaluronic acid losses were greatest when collagen was significantly decreased. The pattern by which chondroitin and keratan sulfates are lost demonstrates that a prominent feature of infectious and noninfectious inflammatory arthritis is a rapid loss of proteoglycan subunits that precedes collagen loss.

ISSN:0736-0266    

DOI:10.1002/jor.1100010204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractRabbits were immunized with bovine serum albumin and later challenged intraperitoneally with the same antigen. Polyarthritis, characterized by synovial lining layer hyperplasia and leukocyte infiltration, was conditional on animals having excess free serum antigen in the presence of circulating immune complexes (IC). Nonimmune controls did not develop polyarthritis following antigen challenge. Data are presented that strongly suggest that synovitis was triggered by deposition of IC in the synovia. During the chronic phase of polyarthritis the synovium was clear of antigen but there was marked retention within joint fibrocartilage, suggesting that antigen, immobilized locally, may maintain the chronic synovitis. Clinical relevance: There are several animal models in which experimental arthritis has been induced by antigenic challenge. The resemblance of the lesions to those of human rheumatoid arthritis has provided the rationale for studying the immune events associated with the onset of acute and maintenance of chronic phases of experimental arthritis.

ISSN:0736-0266    

DOI:10.1002/jor.1100010205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractBilateral total medial meniscectomy was undertaken in the knee joints of 12 adult greyhounds. One‐half of the animals had one meniscectomised joint immobilised by an external fixation system for 5 weeks following meniscectomy. All animals were sacrificed 6 months after surgery. The menisci (regrown and normal) were examined for collagen content and analysed histochemically to assess collagen assembly and glycosaminoglycan (GAG) distribution. Although the collagen content of regrown tissues was not statistically different from normal medial or lateral menisci, the fibre development and GAGs were abnormal. It is concluded that movement following meniscectomy is likely beneficial to the matrix formation in the regenerating tissue, but this together with weight bearing may have a detrimental effect on articular cartilage of the medial joint compartmen

ISSN:0736-0266    

DOI:10.1002/jor.1100010206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractIsokinetic muscle testing has become an increasingly popular method for measuring muscle performance. However, the relationship of isokinetic strength measurements to static strength measurements remains unclear. The relationship between maximal isokinetic and maximal isometric torque was investigated at angular velocities of 24, 48, 96, and 192°/s for both flexion and extension of the elbow joint. Twenty‐four subjects were tested bilaterally, and discrete torque values at the positions of 60 and 90° of flexion were obtained from the continuous isokinetic records for comparison with isometric torques recorded at the same two positions. Data were analyzed using an analysis of covariance with isokinetic torque, the dependent variable, expressed as a function of isometric torque and as a function of the design variables side and position. The results demonstrated significant effects of side and position and also demonstrated the dependence of isokinetic strength on velocity. Confidence intervals were determined for the prediction of isokinetic torque from observed isometric torque for normal individuals, providing a potentially useful tool to aid in the diagnosis of muscular disord

ISSN:0736-0266    

DOI:10.1002/jor.1100010207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThis study was designed to evaluate the functional response of the median nerve at the wrist to various degrees of acute, local compression in hypertensive patients. After measuring resting tissue fluid pressure in the carpal tunnel of the nondominant hand of nine subjects (diastolic pressures of 90 mm Hg or greater), localized pressures of 50, 60, or 70 mm Hg were applied to the palmar aspect of the wrist. Motor and sensory latencies and amplitudes of the median nerve were evaluated before compression, during 30–240 min of compression, and during the postcompression recovery phase. Sensory responses were completely blocked at a threshold tissue fluid pressure of 60–70 mm Hg, measured by the wick catheter technique. This pressure threshold was greater than the 40–50 mm Hg previously found in normotensive subjects. The tissue pressure threshold of normotensive and hypertensive subjects was consistently 30 mm Hg below diastolic blood pressure (approximately 45 mm Hg below mean arterial blood pressure). These results support the concept that ischemia is the prime mechanism of conduction block in low pressure, nerve‐compression sy

ISSN:0736-0266    

DOI:10.1002/jor.1100010208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe purpose of this study was to assess morphologically the healing of repaired medial collateral ligaments (MCLs) in a rabbit model. Healing ligaments were examined grossly and histologically at various intervals, from 3 days to 2 ½ years after injury, and compared with the appearances of normal age‐, sex‐, and activity‐matched controls. Results show that all ligaments healed by bridging scar formation rather than true ligament regeneration. Increases in cellularity and temporary matrix disorganization along the entire length of the ligaments during healing suggest a combination of diffuse mechanical damage from their failure in tension and regional inflammatory injury (in excess of surgical exposure alone) from the processes of degradation and replacement. Substance that was not injured physically in this model demonstrated complete recovery, while that replaced by scar did not. Healing processes were similar to those of other highly specialized soft tissues (e.g., tendons), with short phases of hemorrhage and inflammation, an intermediate phase of proliferation, and a prolonged phase of remodeling. Failure of repairs to maintain anatomical apposition of torn ends may have contributed to the delay of these healing processes by increasing scar mass. Incomplete scar remodeling at 2 ½ years, however, suggests much slower MCL healing than previously reported and probably, therefore, a longer period for potential treatment in

ISSN:0736-0266    

DOI:10.1002/jor.1100010209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

ISSN:0736-0266    

DOI:10.1002/jor.1100010210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY