摘要:

AbstractTopographically, there are both morphological and biochemical differences in the articular cartilage of the tibial plateau of normal adult dogs when the cartilage covered by the meniscus is compared with that more centrally placed and not covered by meniscus. Histologically, differences are present in the surface morphology, in intra‐ and extracellular lipid content, and in the morphology of the mineralization front. Electron microscopy shows, in the covered cartilage, variability in collagen fiber size, with evenly spaced fibers apparently randomly distributed and an orderly relationship between the proteoglycans and collagen, whereas in the uncovered area, the collagen is aggregated into bundles and appears to be dissociated in large part from the proteoglycans. The most striking feature in the biochemistry of the two regions is an increased water content in the uncovered cartilage, as compared with the covered. In addition, there is an increased amount of proteoglycans that can be extracted in the uncovered cartilage. The heterogeneity of the cartilage on the tibial plateau should be taken into account when considering both the histologic and biochemical variations found in osteoarthritic cartilage; and when reflecting on the pathogenesis of osteoarthriti

ISSN:0736-0266    

DOI:10.1002/jor.1100030101

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

年代:1985

数据来源: WILEY

摘要:

AbstractAdult rabbit articular cartilage was prepared for scanning electron microscopy using, in order, glutaraldehyde fixation, enzymatic removal of proteoglycan, dehydration in ethanol, cryofracture in liquid nitrogen, and criticalpoint drying. Enzymes were effective in fixed material. Fixation, cryofracture, alignment of fracture surfaces with “split lines,” and retention of subchondral bone were found to be necessary steps for the preservation of collagen detail. The fibrous framework was found to be similar to that proposed by Benninghoff and favored by more recent phase‐contrast microscopic studies. Vertical fibers extending from subchondral bone and a network of tangentially oriented superficial fibrils converge in the transitional zone. No random layer is seen. Pericellular capsules interdigitate with the vertical fibers. When cartilage is prepared in a manner that minimizes tissue damage, scanning electron microscopy provides useful, unique inform

ISSN:0736-0266    

DOI:10.1002/jor.1100030102

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

年代:1985

数据来源: WILEY

摘要:

AbstractInduction of heat‐shock protein (HSP) synthesis is demonstrated in cultured calf‐chondrocytes at temperatures shown to occur in normal human cartilage during experiments subjecting intact cadaverous hip joints to the parameters of level walking. A 70,000 MW heat‐shock protein (HSP‐70) is synthesized by chondrocytes at temperatures above 39°C, while induction of synthesis of a 110,000 MW HSP only occurs at temperatures of 45°C or greater. These differences in critical temperatures for induction, and data showing differences in kinetics of induction and repression of synthesis, suggest that there are differences in the mechanism of induction of the two HSPs. The duration of HSP synthesis and inhibition of synthesis of normal cellular proteins is directly proportional to the duration and magnitude of the temperature rise. Possible relationships between these new findings and the initiation and progression of degenerative joint disease are

ISSN:0736-0266    

DOI:10.1002/jor.1100030103

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

年代:1985

数据来源: WILEY

摘要:

AbstractThis study was undertaken to determine whether the cells of the fibrocartilaginous meniscal substance are capable of proliferation and matrix synthesis. Cells were isolated from the fibrocartilaginous menisci of young New Zealand white rabbits, and grown in two alternative culture regimens differing only in the basal nutrient medium used to initiate primary monolayer growth. Under each culture regimen, the cells attached and proliferated both initially and after passage into secondary (2°) culture. Differences were noted in cell morphology and time to reach confluence in primary (1°) culture. Upon passage into 2° culture, the fibrochondrocytes assumed two distinct morphological changes were accompanied by differences in the population doubling time and incorporation of35SO4into sulfated proteoglycans. The proliferation of both fibrochondrocyte subtypes was stimulated by the addition of either pituitary fibroblast growth factor (FGF) or human platelet lysate in a dosedependent manner. Both FGF (10 ng/ml) and ascorbate (40 μg/ml) decreased 35‐sulfate incorporation, whereas only ascorbate was found to alter the amount of sulfated glycosaminogly can in the pericellular coat. We conclude that the fibrochondrocytes of the meniscal substance are capable of replication and synthesis of matrix macromolecules if given the proper stimuli. Additionally, there may be two subpopulations of fibrochondrocytes that can be distinguished by theirin vitrobeh

ISSN:0736-0266    

DOI:10.1002/jor.1100030104

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

年代:1985

数据来源: WILEY

摘要:

AbstractTo verify the role of collagenase in reduction of peritendinous adhesion by topical application of exogenous collagen, the flexor tendons of 30 chickens were severed and sutured. Exogenous, native enriched collagen solution (ECS) was introduced in the tendon sheath via a polyethylene catheter. The effect of ECS on collagenolytic activity in the healing tendon was assessed 1, 2, and 3 weeks later both by determining the relative amounts of dialyzable protein and hydroxyproline and by using the collagen film collagenase assay. The results obtained indicated a significant increase in both dialyzable hydroxyproline level and collagenolytic activity in the ECS‐treated tendons as compared with the untreated controls. It is suggested that the effect of the topically applied exogenous collagen on increasing the collagenolytic activity may be directly related to previously observed increased gliding capacity of the tendons in the same experimental mode

ISSN:0736-0266    

DOI:10.1002/jor.1100030105

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

年代:1985

数据来源: WILEY

摘要:

AbstractAlthough the joints of the index finger are similar geometrically and kinematically, the occurrence of degenerative joint disease is more frequent and severe in the distal interphalangeal joint. Much circumstantial evidence exists to suggest a mechanical cause for the observed differences in frequency. This article presents the results of in vitro experiments designed to determine contact areas and average pressures in the joints of the human index finger for positions simulating tip pinch and power grasp. The results show that the highest average contact pressures do, in fact, occur in the distal interphalangeal joint. Average joint contact pressure correlates well with clinically observed patterns of frequency of degeneration and degenerative joint disease score. This correlation between clinical experience and experimental results indicates that mechanical stress is among the factors responsible for the initiation and/or propagation of degenerative joint disease in the joints of the finger.

ISSN:0736-0266    

DOI:10.1002/jor.1100030106

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

年代:1985

数据来源: WILEY

摘要:

AbstractUsing a roentgen‐stereophotogrammetric measurement system, the three‐dimensional kinematic characteristics of each carpal bone in two human wrist joints were obtained as the hands were moved in vitro through dorsopalmar flexion and through radioulnar deviation, both in the supinated and pronated positions of the hand. The results were described in terms of Euler rotation angles and showed that in flexion, the distal carpal bones may be considered as one fixed group while the proximal carpals may not. For the deviation motion, quite different rotational excursions for the carpal bones were observed, therefore, none of the two rows may be assumed acting as rigid groups. In both of the hand motions performed, all carpal bones moved synchronously and uniformly. These results demonstrate that accurate measurements of three‐dimensional carpal‐bone motions are feasible by using an adequately refined roentgen‐stereophotogrammetric system. The detailed and precise kinematic information obtained can serve as a database for future developments of functional wrist‐joint models, and will provide more insight into carpal‐bone behavior, useful in clinical diagnosis and surgical reconstructi

ISSN:0736-0266    

DOI:10.1002/jor.1100030107

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

年代:1985

数据来源: WILEY

摘要:

AbstractThree different porous ceramics—calcium aluminate, calcium hydroxyapatite, and tricalcium phosphate—were implanted into the proximal tibia in rats and rabbits to study the interactions between these ceramics and a bony site that is abundant in bone marrow. New bone was consistently formed within the bone marrow surrounding and adjacent to all three types of ceramics. Calcium hydroxyapatite and tricalcium phosphate ceramics permitted bone ingrowth into their pores. The newly formed bone was found only in the part of the ceramic intruding into the bone, not in the portion protruding in the soft tissues outside the tibia. Partial replacement of the new bone opposite the medullary portion by new hemopoietic marrow occurred with longer implantation times. In contrast, no bone was seen within the pores of any of the calcium aluminate impla

ISSN:0736-0266    

DOI:10.1002/jor.1100030108

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

年代:1985

数据来源: WILEY

摘要:

AbstractIn this preliminary study, the authors have found cytotoxic complement‐dependent synovial antibodies in the serum of patients undergoing prosthesis implantation; these were particularly evident in those patients undergoing revision surgery. In order to demonstrate the synovial antibodies, it was necessary that the authors modify the method they had previously used in their studies of cytotoxic lung and kidney antibodies. While conventional trypsinization dispersion produced synovial target cells that would not react in the test system, mechanical dispersion successfully produced target cells sensitive to complement‐dependent cytotoxic antibodies. In this study, synovial antibodies reacted similarly to cells derived from the synovium of different individuals, but they did not react to cells derived from tissues other than synovium. This tissue specificity was confirmed by absorption studies that indicated the synovial antibodies to be organ specific. Whether these cytotoxic synovial antibodies can be predictive of the impending loss of an artificial prosthesis, or somehow be directly involved in the failure mechanism of that prosthesis, will require additional stud

ISSN:0736-0266    

DOI:10.1002/jor.1100030109

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

年代:1985

数据来源: WILEY

摘要:

AbstractA mathematical model is presented to describe the combined time‐dependent and cycle‐dependent fracture characteristics of devitalized cortical bone. Failure is interpreted based on a linear‐life fraction rule, which accounts for cumulative creep and fatigue damage under arbitrary loading histories. The model is successful in describing the influence of loading rate on monotonic tensile strength, the time to failure in constant stress creep‐fracture tests, and bone fracture in zero‐tension and tension‐compression cyclic loading. The possible implications of the model toin vivobone fracture, deformity, and remodelling in response to various loading histories are

ISSN:0736-0266    

DOI:10.1002/jor.1100030110

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

年代:1985

数据来源: WILEY