摘要:

AbstractTwenty patients were studied prospectively with indium‐labled leukocyte imaging to evaluate its effectiveness in differentiating noninfected delayed or nonunion from osteomyelitis complicating these entities. All patients underwent an open surgical procedure within 24h of the scan. Bone specimens from the nonunion site were obtained for microbiological and histological analysis to confirm the presence or absence of osteomyelitis. In these twenty patients, the sensitivity of the indium scintigraphy was 100%, the specificity 100%, and the overall accuracy 100%. Indium‐labeled leukocyte scintigraphy is significantly more accurate than99mtechnetium and67gallium imaging had been, when studied earlier, in detecting subclinical osteomyelitis complicating nonunion. Indium‐labeled leukocyte scintigraphy should supplant sequential technetium and gallium studies in this patient population when the surgeon must determine whether subclinical osteomyelitis is complicating fracture management of delayed and nonu

ISSN:0736-0266    

DOI:10.1002/jor.1100050102

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe changes in proteoglycan molecules during the initial stages of fracture healing in rats were characterized. Following extraction of callus proteoglycan components with dissociative solvents, the components were purified in a cesium chloride density gradient. The recovered proteoglycans were characterized with respect to their molecular size distribution using gel filtration chromatography and a centrifugal transport methodology. During this early healing period, a decrease was observed in the relative proportion of the aggregate and in the hydrodynamic size and sedimentation coefficients of these molecules. While some molecular degradation could have occurred during the early stages of fracture healing, the dominant change of the proteoglycan molecules seemed to be disaggregation. No significant difference was observed in the proportion of aggregates reformed when exogenous hyaluronate and link glycoproteins. The molecular changes of the proteoglycan molecules seem to parallel those occurring during endochondral calcification of rat epiphyseal cartilage.

ISSN:0736-0266    

DOI:10.1002/jor.1100050103

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe healing patterns of trabecular bone are different from those of compact bone. In order to investigate further this observation, a histomorphometric assessment was undertaken. The influence of internal fixation devices on trabecular bone healing was also studied. Intercondylar osteotomies were produced in 19 dogs and fixed with screws. All dogs were killed between 1 and 14 weeks; eight of them had the screws removed 4 weeks after osteotomy and were killed 4 or 10 weeks later. The results of morphometry were compared to the histologic and radiologic pictures. Anatomic reduction with stable fixation led to contact healing characterized by a narrow endosteal bone formation at the osteotomy site that disappeared only after union was complete (4 weeks). In gap healing, the endosteal bone formation was greater. Internal fixation devices appeared to cause a diffuse osteopenia once union was complete. Their removal just after completion of union seems to prevent the bone loss. Screws induced bone formation around their threads; after they were removed, the reaction disappeared but the screw holes were not filled with normal trabeculate 10 weeks later. Union of fractures through trabecular bone can be assessed radiologically. A decrease of band‐like bone density at the fracture site indicates completion of union. This is the optimal time for implant removal. It prevents the osteopenia observed in cases of continuous presence of screw

ISSN:0736-0266    

DOI:10.1002/jor.1100050104

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

年代:1987

数据来源: WILEY

摘要:

AbstractStudies of infections in open fractures are described. The hamster was chosen as the experimental model. Osteotomies of the femur were created with an osteotomy saw. Some osteotomies were left to heal and others were fixed with an 0.9mm K‐wire. The infection rates in fixed and unfixed fractures were compared. The first group of hamsters with fixed and unfixed osteotomies was returned to cages with open wounds. There was no difference in the infection rate at 2 weeks. The second group was deliberately contaminated withStaphylococcus aureusand then returned to cages with open wounds. In this group, the infection rate at 2 weeks was lower in the internally‐fixed fractures than in the unfixed fractures. The third group was deliberately contaminated with the gram negative organismProteus mirabilis. In these animals, the infection rate was increased in the presence of the internal fixation device. The fourth group was deliberately contaminated with bothStaphylococcus aureusandProteus mirabilis. The infection rate in these animals was very high; Proteus was recovered from those animals with internal fixation andStaphylococcuswas recovered from those animals without internal fixation. These studies in the hamster document the usefulness of this animal as an inexpensive and reproducible model for studying infection of open fractures. The hamsters tolerated the procedure well, and wound and fracture healing progressed satisfactor

ISSN:0736-0266    

DOI:10.1002/jor.1100050105

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

年代:1987

数据来源: WILEY

摘要:

AbstractNinety‐six rats underwent a midshaft transverse osteotomy followed by osteosynthesis with an intramedullary nail, so that the effect of bending instability on time to union and on the mechanical properties of experimental diaphyseal fracture could be evaluted. Rotation was reduced by cementing both nail ends to the bone. Rigid nails made of stainless steel were used on one group and flexible nails made of polyacetal resin were used on another group. Serial radiographs were evaluated at 4‐6‐week intervals. Twelve animals with either nail type were killed at 4, 8, 16, and 24 week. Both femora were mechanically tested and the callus diameters were measured. There was no significant difference in time to union between the two groups. The cross‐sectional area of callus was significantly higher at 8 and 16 weeks in femora with flexible nails. The strength, toughness, and resilience of the bone increased in this group until 24 week. Between 16 and 24 weeks, these parameters did not improve in femora with rigid nails. Poorer mechanical properties in femora with steel nails are interpreted as an effect of stress protection of the bone. This study, therefore, indicates that flexible nails prevent stress protection effects without delayin

ISSN:0736-0266    

DOI:10.1002/jor.1100050106

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

年代:1987

数据来源: WILEY

摘要:

AbstractMonomer and aggregated proteoglycans were prepared from piglaryngeal cartilage. Vascoelastic flow properties, comprising linear complex dynamic shear modulus, nonlinear steady‐state shear‐rate dependent viscosity, and primary normal stress difference, were measured in proteoglycan solutions containing varying proportions of aggregate (0–80%) and at different concentrations (10–50 mg/ml). Results were analyzed using the simple Oldroyd four‐parameter nonlinear rate‐type rheological equation. All solution properties were strongly dependent on proteoglycan concentration and on the proportion of aggregates present. Aggregation was found to have a great effect on the zero shear‐rate viscosity at 50 mg/ml, which increased fivefold from 0–100% aggregate. The results showed that network formation in proteoglycan solutions increased with concentration from 10–50 mg/ml and also increased with aggregation. All proteoglycan solutions showed shear thinning, which was most marked with aggregated proteoglycan at high concentration (50 mg/ml), where the viscosity decreased tenfold from the zero shear‐rate limit to the infinite shear‐rate limit. The intermolecular interactions in the network were therefore increasingly disrupted by increasing shear rate, but repeated measurements showed that these were reversible changes and that testing did not induce disaggregation or degradation of proteoglycan. These rheological properties show that aggregation is likely to immobilize proteoglycan at high concentration within cartilage and to contribute to the material properties of the porous solid matrix of articular cartilage that are important for its

ISSN:0736-0266    

DOI:10.1002/jor.1100050107

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

年代:1987

数据来源: WILEY

摘要:

AbstractBilateral medial meniscectomy was undertaken in 14 mature beagles. Another two underwent arthrotomy (sham‐operated controls). One week after surgery, six of the meniscectomised animals were administered glycosaminoglycan polysulphate (Arteparon) (2 mg/kg) subcutaneously three times a week for 3 weeks, then twice weekly until killed 23 weeks later. Two months before death all animals were given Na235SO4(1.0 mCi/kg) intravenously. At autopsy, articular cartilage (AC) from the medial and lateral compartments, as well as from the femoral trochlear groove and femoral head, was sampled. Proteoglycans (PGs) were isolated by 4.0MGuanidine hydrochloride (GuHCI) extraction of AC and purified by ultracentrifugation. The PG monomers were assayed for hexuronic acid, protein, and hexosamines (galactosamine/glucosamine), and their ability to aggregate. The results indicated that Arteparon provided some protective effect to AC in the menisectomised compartment as demonstrated histologically by reduced surface fibrillation, diminished chondrocyte cloning, and maintence of alcianophilia. The levels of PGs and hexuronate‐protein ratios in medial AC of drug‐treated meniscectomised animals were found to be comparable to sham controls, whereas these parameters in the nondrug‐treated meniscectomized group were de

ISSN:0736-0266    

DOI:10.1002/jor.1100050108

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

年代:1987

数据来源: WILEY

摘要:

AbstractTo define the matrix composition and architecture of canine flexor tendon, and to correlate tissue structure with applied mechanical loading, five anatomical regions of flexor tendon were studied. Histologically, two prominent fibrocartilaginous areas were observed on concave aspects of the tendon. The location of the major fibrocartilaginous area at the metacarpophalangeal joint correlated well with the region predicted by biomechanical modeling to be under greatest compressive loads during standing and claw movement. Comparative biochemical analysis showed an elevated water content, a fivefold higher hexuronic acid content, and a larger hydroxylysine/hydroxyproline ratio in this region relative to that for more tendinous areas. The major glycosaminoglycan component of fibrocartilaginous areas was chondroitin sulfate, whereas in other areas dermatan sulfate and hyaluronic acid dominated. Cell density and DNA analyses indicated a slightly higher cellularity for fibrocartilaginous areas and the region of vinculum insertion. These data document the existence of discrete areas of specialization within the flexor tendon that appear to be an adaptation to nutritional and mechanical factors.

ISSN:0736-0266    

DOI:10.1002/jor.1100050109

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe aim of this study is an experimental evaluation of a force analysis of the patellar mechanism based on the assumption that patellofemoral contact is frictionless. At first, the geometric characteristics of contact surfaces, a prior knowledge of which is necessary for quantitative analysis, were measured from radiographs of 42 fresh‐frozen knee specimens in the flexion range 0–120°. The results were then used in the analysis to predict the relations between the forces acting on the patella. For the evaluation of the analysis, the ratio of the tension in the ligamentum patellae and the rectus femoris was measured in ten specimens during simulation of two knee functions: (1)“leg raising” against a resistance; and (2)“static lifiting”. The effect of flexion angle on the ratio is found to be rather complex. With increasing flexion, the ratio increases initially up to 30°, then decreases up to 90°, and finally increases again beyond 90°. The ratio is above unity up to around 45° and below that in the remaining flexion range. The analysis has been found to predict not only the characteristic variation of the ratio but also its magnitude with reasonable accuracy. It has been concluded that for an accurate prediction of the patellofemoral joint reaction, the force analysis needs to be based on the geometry of the contact surfaces. This implies that the mechanical consequences of surgical procedures involving tibial tubercle relocation cannot be inferred simply on the basis of their effect on the patellar mechanism angle, but that they also require consideration of their effect on the

ISSN:0736-0266    

DOI:10.1002/jor.1100050110

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

年代:1987

数据来源: WILEY

摘要:

AbstractThis study describes a clinically oriented anatomical assessment of anteversion on 32 cadavers ranging from 61 to 89 years. The method used a three‐dimensional reference system based on functional axes of the femur. Each soft tissue‐free femur was mounted on an osteometric table and aligned to its functional axes. The long axes were defined as passing from the centre of the femoral head to the femoral attachment of the posterior cruciate ligament (PCL). A line that ran through the PCL attachment (equal distal origin of this system) and was parallel to a transepicondylar line served as a transverse axis. Anteversion of the femur was defined as an angle formed to the transverse axis by a line running through the centre of the femoral head through the midpoint of the narrowest segment of the femoral neck. The measurement mean for anteversion among these specimens was 7.4° with a range from −10.8° (retroversion) to 22.1°. There was no statistical difference in mean values (p<0.05) between sexes or between right and left sides of the group; however there were large variations for anteversions when each side in the same individual was compared (although there was no dominant side). Retroversions were observed in four of 32 femurs (12.5%). No correlation was found between the anteversion in these femurs and rotational geometry at the knee. We compared our data with those obtained by conventional techniques, by which anteversion for each femur was measured after the bone had been placed on a flat surface. The anteversion so defined was 13.1°, i.e., an average of 5.7° more external rotation induced by condylar disproportion. Such data indicate the influence of condylar disproportion on the measurement of anteversion and reveal the potential errors in measurements of anteversion that may be imposed by variations in condylar dimensions. The measurement method may be applied to computer tomographic radiographs of femo

ISSN:0736-0266    

DOI:10.1002/jor.1100050111

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

年代:1987

数据来源: WILEY