ISSN:0736-0266    

DOI:10.1002/jor.1100140202

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

年代:1996

数据来源: WILEY

摘要:

AbstractDespite an increasing reliance on the use of health status measures to assess and evaluate medical care, no single instrument is currently available for use with the broad range of patients with musculoskeletal disorders of the extremities that is commonly seen in clinical practice. In this paper, we report on the development of the Musculoskeletal Function Assessment instrument, a 100‐item self reported health status instrument that is designed to meet this need. The instrument was developed in two phases During the first phase, items were selected on the basis of interviews with 135 patients and 12 clinicians and from reviews of existing health status instruments. The items then were grouped into categories. During the second phase, the instrument was tested for reliability and content validity using a sample of 327 patients with one of five musculoskeletal disorders of the upper and lower extremities (fractures, soft‐tissue injuries, repetitive motion disorders, osteoarthritis, and rheumatoid arthritis). The patients were selected from both community and academic sites. The Musculoskeletal Function Assessment instrument met standards for test‐retest reliability and internal consistency. Content validity also was demonstrated, based on a review of item selection procedures, expert opinion, and the distribution of scores on the instr

ISSN:0736-0266    

DOI:10.1002/jor.1100140203

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

年代:1996

数据来源: WILEY

摘要:

AbstractThe Musculoskeletal Function Assessment (MFA) instrument, a health status instrument with 100 self‐reported health items; was designed for use with the broad range of patients with musculoskeletal disorders of the extremities commonly seen in clinical practice. In this paper, we report on its criterion and construct validity. Criterion validity was tested against physicians' ratings of patient functioning (e.g., upper functioning, lower functioning, daily activities, recreational functioning, emotional adjustment, and overall functioning) and standard clinical measures (e.g., grip strength, walking speed, fine motor skills, knee and elbow strength, and range of motion). Significant correlations (p ⩽ 0.05) between its scores, physicians' ratings, and clinical measures support the MFA's criterion validity. Construct validity was demonstrated against existing measures of health status (e.g., measures of lower and upper mobility, activity level and satisfaction, health status, social support, pain, emotional status, and quality of life), in accordance with clinical hypotheses about the effect of musculokeletal disorders on functioning (e.g., type and number of problems, severity of illness or injury, and comorbidites) and by an analysis of demographic characteristics (e.g., sex, education, income, health insurance, and employment) against the MFA scores. Discriminant construct validity was supported in an analysis of MFA scores by patient disease groups (p ⩽

ISSN:0736-0266    

DOI:10.1002/jor.1100140204

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

年代:1996

数据来源: WILEY

摘要:

AbstractThe innervation of the rat and human anterior cruciate ligament, patellar tendon, and patellar tendon autograft after reconstruction of the anterior cruciate ligament was investigated by immunohistochemical and histological methods. A rat model of reconstruction with patellar tendon autograft was evaluated during active graft remodelling (2–16 weeks) and compared with normal ligament and tendon. The knees of 10 patients who had undergone reconstruction with patellar tendon autograft were examined 5–37 months postoperatively (remodelling fully completed) with arthroscopy and biopsy. As a control, biopsies from normal ligament and tendon were obtained from four patients. Nerve fibers were identified using antisera for protein gene product 9.5, a general neural marker. Neuronal regeneration was assessed by the expression of growth‐associated protein 43/B‐50. The sensory type of innervation was characterized by assessing the distribution of nerves containing the sensory neuropeptides calcitonin gene related peptide and substance P. Immunoreactivity for all neural markers was found in both rat and human anterior cruciate ligament and patellar tendon. Two weeks after reconstruction, the rat autograft was acellular and no innervation could be identified. After 4 weeks, the grafts were viable, and immunoreactivity for protein gene product 9.5, growth associated protein 43/B‐50, and calcitonin gene‐related peptide was found until the 16th week postoperatively. Immunoreactivity for substance P was found in rat autografts at 4 weeks postoperatively only. All biopsies of human patellar tendon autograft showed signs of the remodelling process being fully completed, with revascularization and a sinusoidal collagen pattern with fibroblast repopulation. Neuropeptide immunoreactivity, however, was not found. The presence of immunoreactivity to sensory neuropeptides in the anterior cruciate ligament and patellar tendon may indicate a nociceptive and neuromodulatory function of these structures. The expression of sensory neuropeptides in the rat patellar tendon autograft suggests a possible involvement of sensory innervation during healing o

ISSN:0736-0266    

DOI:10.1002/jor.1100140205

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

年代:1996

数据来源: WILEY

摘要:

AbstractWe investigated the effects of growth factors on the proliferation and matrix synthesis of anterior cruciate ligament fibroblasts. Fibroblasts from the anterior cruciate ligaments of dogs were transferred at the second passage in a defined medium. Epidermal growth factor, platelet‐derived growth factor‐AB, transforming growth factor‐β1, insulin‐like growth factor‐1, and insulin, combined two by two following a 5 × 5 logarithmic concentration matrix, were added. Tridimensional curves showing cell proliferation at 24 hours against the concentration of two effectors were obtained for each combination. Collagen and proteoglycan productions were quantified using [14C]glycine and Na2[35S]O4. Ratios of type I:III collagen and hydrodynamic size distributions of proteoglycans were assayed, respectively, by sodium dodecyl sulfate‐polyacrylamidel gel electrophoresis and gel filtration chromatography. Epidermal growth factor had an effect nearly equivalent to that of platelet‐derived growth factor‐AB on cell proliferation. Both had a greater effect than insulin‐like growth factor‐1, which in turn had a greater effect than both the effect of insulin or the nearly equivalent effect of transforming growth factor‐β1. Neither platelet‐derived growth factor‐AB nor insulin has a significant effect by itself on collagen production. Epidermal growth factor slightly decreases collagen production as well as the type I:III collagen ratio: both transforming growth factor‐β1and insulin‐like growth factor‐1 increase the same parameters. Epidermal growth factor inhibits the stimulation induced by transforming growth factor‐β1. Similarly, insulin decreases the response to insulin‐like growth factor‐1. Proteoglycan production was significantly increased by all growth factors in this study, with transforming growth factor‐β1having the strongest effect, Small hydrodynamic size of proteoglycan was correlated to a high level of proteoglycan biosynthesis. The results may be readily applied to tissue engineerin

ISSN:0736-0266    

DOI:10.1002/jor.1100140206

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

年代:1996

数据来源: WILEY

摘要:

AbstractIt has been hypothesized that load affects the mechanical properties of an anterior cruciate ligament graft while it remodels. The goal of this study was to use an existing goat model to evaluate the effect of intraoperative set force on the postoperative mechanical properties of an autograft that had been augmented with a synthetic segment. The following questions were addressed. Do augmented autografts set with a high force intraoperatively have improved structural and material graft properties and lower anterior‐posterior knee laxity at 3 months after surgery, compared with autografts set with a low intraoperative force? How do the structural and material properties of these implanted autografts compare with the mechanical properties of an intact anterior cruciate ligament or an unimplanted control autograft? The anterior cruciate ligament was reconstructed in seven goats with use of a composite graft consisting of a bone‐patellar tendon‐bone autograft and a synthetic augmentation device. A force‐setting technique was used intraoperatively to establish the load‐sharing between the autograft and augmentation segments such that the autograft carried either a high (16.5 N in four animals) or low (1.5 N in three animals) level of force, while the total force in the composite graft remained constant. Tensile testing was performed at 3 months after surgery to determine the material and structural properties of the autograft, the intact anterior cruciate ligament from the normal contralateral knee, and a control bone‐patellar tendon‐bone graft of similar size that was harvested from the contralateral knee at the time of necropsy and had never been implanted in the joint. The structural and material properties of the autografts initially set to high or low loads at surgery were not significantly different after 3 months of implantation. The strength and stiffness of the implanted tendons were an average of 24 and 20% of the strength and stiffness of the normal anterior cruciate ligament and 31 and 62% of the control tendons, respectively. Intraoperative set force in an augmented anterior cruciate ligament graft at the levels chosen in this study did not significantly affect weakening of the autograf

ISSN:0736-0266    

DOI:10.1002/jor.1100140207

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

年代:1996

数据来源: WILEY

摘要:

AbstractLigamentous injuries range in severity from a simple sprain to a complete rupture. Although sprains occur more frequently than complete failures, only a few studies have investigated the phenomena of these subfailure injuries. The purpose of our study was to document the changes in the load‐deformation curve until the failure point, after the ligament has been subjected to an 80% subfailure stretch. Thirteen paired fresh rabbit bone‐anterior cruciate ligament‐bone preparations were used. One of the pairs (control) was stretched until failure; the other (experimental) was first stretched to 80% of the failure deformation of the control and then stretched to failure. Comparisons were made between the load‐deformation curves of the experimental and control specimens. The nonlinear load‐deformation curves were characterized by eight parameters: failure load (Ffail), failure deformation (Dfail), energy until failure (Efail), deformations measured at 5, 10, 25, and 50% of the failure load (D5, D10, D25, and D50, respectively), and stiffness measured at 50% of the failure force (K50). There were no significant differences in the values for Ffail, Dfail, and Efailbetween the experimental and control ligaments (p>0.33). In contrast, the deformation values were all larger for the experimental than the control ligaments (p<0.01). The deformations D5, D10, D25, and D50(mean ± SD) for the control were 0.36 ± 0.13, 0.49 ± 0.23, 0.81 ± 0.35, and 1.23 ± 0.41 mm. The corresponding deformations for the experimental ligaments were, respectively, 209, 186, 153, and 130% of the control values. K50was also greater for the experimental ligament (125.0 ± 41.7 N/mm compared with 108.7 ± 31.4 N/mm, p<0.03). These findings indicate that even though the strength of the ligament did not change due to a subfailure injury, the shape of the load‐displacement curve, especially at low loads, was significantly altered. Under the dynamicin vivoloading conditions of daily living, this may result in increased joint laxity, additional loads being applied to other joint structures, and, with time,

ISSN:0736-0266    

DOI:10.1002/jor.1100140208

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

年代:1996

数据来源: WILEY

摘要:

AbstractThe optimal treatment for concurrent injuries to the medial collateral and anterior cruciate ligaments has not been determined, despite numerous clinical and laboratory studies. The objective of this study was to examine the effect of surgical repair of the medial collateral ligament on its biomechanical and biochemical properties 52 weeks after such injuries. In the left knee of 12 skeletally mature New Zealand White rabbits, the medial collateral ligament was torn and the anterior cruciate ligament was transected and then reconstructed. This is an experimental model previously developed in our laboratory. In six rabbits, the torn ends of the medial collateral ligament were repaired, and in the remaining six rabbits, the ligament was not repaired. Fifty‐two weeks after injury, we examined varus‐valgus and anterior‐posterior knee stability; structural properties of the femur‐medial collateral ligament‐tibia complex; and mechanical properties, collagen content, and mature collagen crosslinking of the medial collateral ligament. We could not detect significant differences between repair and nonrepair groups for any biomechanical or biochemical property. Our data support clinical findings that when the medial collateral and anterior cruciate ligaments are injured concurrently and the anterior cruciate ligament is reconstructed, conservative treatment of the ruptured medial collateral ligament can result in successfu

ISSN:0736-0266    

DOI:10.1002/jor.1100140209

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

年代:1996

数据来源: WILEY

摘要:

AbstractThe specific objective of this study was to determine the chronology of the appearance of the myofibroblast in the healing ligament. The overall goal of our work is to elucidate the cellular mechanism of contraction in this tissue. The myofibroblast has been found to be responsible for wound contraction in many tissues and to be the cause of the contracture in several pathological conditions. This cell type contains the actin isoform previously thought to be unique to smooth muscle cells and displays certain characteristic features at the ultrastructural level. In 26 New Zealand White male rabbits, the right medial collateral ligament was transected, whereas the left medial collateral ligament received a sham operation. The central third of the ligament (ligament scar tissue) was evaluated at 2, 3, 6, 8, 10, and 12 weeks postoperatively by immunohistochemical techniques, transmission electron microscopy, and Western blot analyses. Three other rabbits served as anatomic controls. During the early reparative phase (2 and 3 weeks after transection), there was an increase in the number of cells containing α‐smooth muscle actin as well as augmentation of the α‐smooth muscle actin content within each cell—a finding attributed to smooth muscle cells and pericytes associated with neovascularity. No myofibroblasts were detected at this stage, immediately postoperatively, or in the sham‐operation controls. Ligaments in the remodeling phase of healing (6, 8, 10, and 12 weeks) exhibited α‐smooth muscle actin in fibroblasts (myofibroblasts) as well as in vascular pericytes and smooth muscle cells. During this stage of healing, transmission electron microscopy demonstrated an increase in the number of cells displaying myofibroblastic features. It was estimated that at 12 weeks of healing 10% of the cells at the site of injury were myofibroblasts. This is the first definitive finding of myofibroblasts in the injury site of the healing ligament, to our knowledge. The appearance of myofibroblasts in the 6–12 week healing period, the interval during which the ligament has been shown to contract in studies by other investigators, is a rationale for a hypothesis that a cellular contractile apparatus comprising α‐smooth muscle actin (i.e., the myofibroblast) may contribute to the recovery of original ligament length (and nor

ISSN:0736-0266    

DOI:10.1002/jor.1100140210

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

年代:1996

数据来源: WILEY

摘要:

AbstractA simplified three‐dimensional finite element model of the femoral component of a cemented total hip prosthesis was used to investigate whether partial debonding at the stem‐cement or bone‐cement interfaces propagates in a stable or unstable manner, and to assess the resultant variation of the stresses within the cement layer. The likelihood of unstable debonding under tensile failure mode was assessed both by a conventional monotonic strength criterion and by a fracture mechanics approach that took into account debonding due to fatigue loading. The model predicted that partial debonding at the cement interfaces would be stable and would not precipitate complete debonding. Among the various bonding conditions that were investigated, the maximum tensile stress within the cement layer was least with a small amount of debonding rather than with complete bonding. These results were consistent with clinical observations of nonprogressive or slowly progressive separation at cement interfaces in cemented femoral components that were otherwise well functioning and asympto

ISSN:0736-0266    

DOI:10.1002/jor.1100140211

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

年代:1996

数据来源: WILEY