ISSN:0736-0266    

DOI:10.1002/jor.1100110202

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

年代:1993

数据来源: WILEY

摘要:

AbstractNaproxen is a nonsteroidal anti‐inflammatory drug commonly used in the clinical treatment of joint disease. In this study, its effect in vivo on the biochemical composition, metabolic activities, and metalloproteinase activities of normal canine articular cartilage was analyzed. The articular cartilage from the knee joints of dogs who had been given naproxen for 4 weeks to maintain a serum level of 40–50 μg/ml was examined. Control animals were given a placebo. Treatment with naproxen was not found to change the composition (water, collagen, and proteoglycan) of the articular cartilage. The culture studies of cartilage explants indicated that proteoglycan synthesis rates were unaffected by the treatment with naproxen but that proteoglycan release from the tissue was suppressed. Analysis of the cartilage for matrix metalloproteinase activities showed reduced activity of neutral matrix metalloproteinase by 80%, of collagenase by 40%, and of gelatinase by 87%, with no change in activity of acid metalloproteinase or of tissue inhibitor for metalloproteinase. These findings indicate that in vivo treatment with naproxen has the capacity to modulate catabolic activities in articular carti

ISSN:0736-0266    

DOI:10.1002/jor.1100110203

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

年代:1993

数据来源: WILEY

摘要:

AbstractA select group of cartilage proteoglycans (fetal human, porcine, and canine articular cartilages and human osteophytes, all depleted of chondroitin sulfate) produces progressive polyarthritis and spondylitis in BALB/c mice. The development of the disease in this murine strain is dependent on the expression of both cell‐mediated and humoral immunities to host mouse cartilage proteoglycan. Autoantibodies have been detected in sera of arthritic animals from the fifth to sixth week after immunization, and their appearance precedes the development of the first clinical symptoms by a few days in animals with passively transferred arthritis. In this preliminary experiment, we describe several functional tests and gait analyses in normal mice, in acutely and chronically arthritic mice, and in randomly selected mice with proteoglycan‐induced and collagen‐induced arthritis. The procedures revealed that changes in joint use and gait could predate by weeks the appearance of the first clinical symptoms (joint swelling, redness, and joint stiffness) of arthritis in mice. Moreover, abnormalities measured by functional tests, such as strength of grip and maintenance of posture on sandpaper, wood, or vinyl surfaces at three different tilt angles (30, 45, and 60°), and gait analysis preceded the appearance of autoantibodies in sera of immunized animals; this indicates that such measurements could provide a noninvasive and simple method to assess joint function accurately during the development of art

ISSN:0736-0266    

DOI:10.1002/jor.1100110204

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

年代:1993

数据来源: WILEY

摘要:

AbstractWe studied the effects of solvent preservation with and without gamma irradiation on the material properties and morphology of canine tendons. Twenty‐four paired tendons were harvested from both hind limbs of eight dogs. The tendons from the right legs were divided into three treatment groups of eight tendons each. In the first group, the tendons were subjected to solvent preservation for sterilization and drying (solvent group). In the second group, the tendons were treated in the same manner and then were sterlized by gamma irradiation (solvent/gamma group). The same treatments were applied to the tendons in the third group but in reverse order (gamma/solvent group). Tendons from the contralateral left legs were frozen immediately for use as controls for each corresponding treatment group. Histologically, the tendons treated with solvent, with or without gamma irradiation, had a more prominent wavy pattern in the collagen fibers than the control tendons. Mechanically, the tangent moduli for the solvent, solvent/gamma, and gamma/solvent groups were 58.53, and 99%, respectively, of each contralateral control. The respective tensile strengths were 85, 39, and 86% of that of the contralateral control. The tendons in the solvent/gamma group underwent the most severe changes in material properties: the tendons in the gamma/solvent group changed the least. This suggests that gamma irradiation followed by solvent drying is the procedure of choice for the preservation of tendon allograft

ISSN:0736-0266    

DOI:10.1002/jor.1100110205

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe objectives of this experimental study were to determine (a) how quickly the medial collateral ligament (MCL) and the anterior cruciate ligament (ACL) elongate when a lateral impact force is imparted to the knee and if a person can react rapidly enough to provide protective muscle forces in the case of such an impact. (b) if the MCL and the ACL elongate simultaneously during a lateral impact, and (c) if resection of the ACL affects elongation of the MCL during a lateral impact. Eight whole‐leg cadaver specimens were used. Each leg was mounted vertically in a testing‐frame with the knee in 0 and 30° of flexion. A submaximal impact was delivered from the lateral side by a pendulum instrumented with a force transducer. Elongation of the midsubstance of the MCL and the ACL was measured with Hall‐effect displacement transducers. The ACL was resected and the entire test sequence was repeated. Following a lateral impact, elongation of the MCL and ACL reached peak values by 70 ms. This study indicated that contraction of the leg musculature would not protect the MCL and ACL from injury when a lateral impact load is applied to the knee. The MCL and the ACL never elongated simultaneously during a lateral impact. After lateral impact loading, the time required to reach maximum elongation (peak delay) averaged 52 ms in the anterior MCL fibers and 61 ms in the ACL when the knee was in 0° of flexion. At 30° of flexion, the peak delay averaged 38 ms in the anterior MCL fibers and 22 ms in the ACL. The peak delay of the ACL was significantly greater than that of the MCL at 0° of the flexion (p<0.05). The opposite was true at 30° of flexion. Resection of the ACL had only minimal effect on the elongation behavior

ISSN:0736-0266    

DOI:10.1002/jor.1100110206

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe Maquet procedure — elevation of the anterior tibial tubercle — has been recommended for treatment of symptomatic osteoarthrosis of the patellofemoral joint. Although the operation was first described 30 years ago, it remains controversial, both on a clinical and on a biomechanical basis. In addition, deterioration of the long‐term results has been suggested. One of the variables that has been ignored in both clinical and biomechanical studies has been tibial shingle length. In order to judge its effect, we examined contact pressures and areas in 15 cadaver knees with 7 and 20 cm tibial shingle lengths. We found significant patellofemoral pressure diminution only with 2 cm elevations. The short anterior tibial shingle with 2 cm of elevation tipped the patella on its superior pole, with a significant change in angle between the patella and the shingle. We suggest that this creates a potentially less than desirable biomechanical circumstance and believe it may explain the discrepancies among previously published re

ISSN:0736-0266    

DOI:10.1002/jor.1100110207

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe purpose of this study was to examine how substance P affects the mechanosensitive afferent units identified in the tissues around and in the lumbar facet joint of the rabbit. Substance P was applied to the receptive fields of the units by microinjection, and the afferent activity of the units was recorded from dorsal root filaments. Changes in afferent discharge rates and von Frey thresholds were measured sequentially after the application of substance P. Most of the units (83.3%) had an increase in the ongoing discharge rates after the application of substance P: 54.2% of the units had immediate excitation and 29.2% had delayed excitation. One‐third of the units had a decreased von Frey threshold after the application of substance P. Substance P had an excitatory effect on 81.8% of the units with a threshold of>5.0 g and a conduction velocity of ≤30 m/s, which may serve as nociceptors, and on 84.6% of the units with a threshold of ≤2.0 g, which may serve as proprioceptors. These results suggest that substance P has an excitatory effect on both nociceptive and proprioceptive units in the tissues around and in the lumbar facet

ISSN:0736-0266    

DOI:10.1002/jor.1100110208

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

年代:1993

数据来源: WILEY

摘要:

AbstractWe measured simple and complex balance responses with a force plate stabiliometer in 70 adolescents: 50 with idiopathic scoliosis (IS) and 20 controls. In stable static balance positions, the two groups performed similarly, but when the visual and somatosensory systems were challenged simultaneously, the IS group had a significantly higher mean body sway than the controls. Within the IS group, children with mild, nonprogressive curves that had not been operated on were significantly more likely to maintain their balance when the visual and somatosensory systems were challenged simultaneously than those with curves ≥40°, who had had surgery, and who had more rapid progression of the curve. These findings suggest that adolescents with IS have normal balance in static, stable positions but are not able to perform as well as normal adolescents in sensory‐challenged positions, particularly if they have a severe, progressive curve. Longitudinal studies are needed to determine whether balance dysfunction can be used to predict progression of the c

ISSN:0736-0266    

DOI:10.1002/jor.1100110209

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe viscoelastic behavior of the cartilaginous end‐plate of the baboon (Papio anubis) was studied in an experiment on compressive creep. Data were analyzed with the biphasic poroviscoelastic constitutive theory to assess the relative contributions of flow‐dependent and flow‐independent viscoelastic mechanisms to the observed creep behavior. Material coefficients describing the equilibrium compressive behavior (HA) and both flow‐independent (c, τ1, and τ2) and flow‐dependent (K) viscoelastic effects were determined for the end‐plate by the curve‐fitting of the theoretical solution to the experimental creep data. Biochemical analyses were performed to test for potential relationships between material properties and composition which may give rise to the viscoelastic behavior of the end‐plate. The results indicate that the cartilaginous end‐plate has a hydraulic permeability of 14.3 × 10−14m4/N‐s, which is associated with rapid transport and pressurization of the interstitial fluid in response to loading and an increased emphasis on flow‐independent viscoelastic effects. Biochemical analyses for water, sulfated glycosaminoglycan content, and hydroxyproline indicate that end‐plate of the baboon is compositionally similar of the cartilaginous end‐plate in humans. Interpretation of the mechanical and compositional data suggests that fluid pressurization in the cartilaginous end‐plate may be important in the maintenance of a uniform stress distribution across the boundary between verteb

ISSN:0736-0266    

DOI:10.1002/jor.1100110210

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

年代:1993

数据来源: WILEY

摘要:

AbstractAllograft transplantation with concomitant chemotherapy has proven successful in the treatment of malignant bone tumors. However, these chemotherapeutic agents may delay tissue healing, resulting in clinical complications. To clarify the effects of cisplatin on the healing of bone grafts, we studied the incorporation of stably fixed massive diaphyseal femoral syngeneic and allogeneic grafts in rats treated with cisplatin. These data were compared with those of historical controls from animals that did not receive cisplatin. Rats that were to receive a fresh syngeneic graft or frozen allogeneic graft were given cisplatin every 4 weeks starting 9 weeks preoperatively and continuing until the time of death. The total bone area of the graft in animals that received cisplatin was smaller than that of the graft in untreated control rats that did not receive cisplatin. The area of the frozen allograft did not increase between 2 and 4 months. Revascularization was incomplete in cisplatin‐treated groups at 2 months, but by 4 months, vessel ingrowth in fresh syngeneic grafts approached control values. Frozen allografts remained poorly revascularized at 4 months. Host‐graft union was poor at 2 months in cisplatin‐treated rats compared with controls. In cisplatin‐treated rats, the host‐graft union of the frozen allograft remained inferior at 4 months while that of the syngeneic graft improved. Allogeneic cortical bone grafts are incorporated more slowly and incompletely than syngeneic grafts, and this handicap is exacerbated by the administration of

ISSN:0736-0266    

DOI:10.1002/jor.1100110211

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

年代:1993

数据来源: WILEY