Showing papers in "Journal of Orthopaedic Research in 1985"

TL;DR: Freezing and storage, even for long periods, do not significantly alter the physical properties of cadaveric spinal specimens, and the mean value of the maximum displacement for the 1st day did not differ significantly from the corresponding mean value for the 13 consecutive days.

TL;DR: The experimental protocol and results clearly demonstrate that two concentration‐dependent material properties are necessary to describe the chemical dependence of tissue swelling stress in uniaxial compression over the range of deformations and concentrations explored.

TL;DR: A mathematical model is presented to describe the combined time‐dependent and cycle‐dependent fracture characteristics of devitalized cortical bone, which 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.

TL;DR: An analytc model for human hand force analysis was developed through anatomical study and measurement of multiple cadaveric specimens to determine muscle and joint force distributions under various isometric hand functions.

TL;DR: Two kinds of coralline hydroxyapatite (CHA), along with sintered triculcium phosphate (TCP), were evaluated and CHA‐Goniopora did not show appreciable degradation until 24 weeks, in contrast, CHAG did not shows appreciable degraded Until 24 weeks.

TL;DR: It is concluded that the fibrochondrocytes of the meniscal substance are capable of replication and synthesis of matrix macromolecules if given the proper stimuli and there may be two subpopulations of fibroChondroCytes that can be distinguished by their in vitro behavior.

TL;DR: Results show that surface electrode data represent a more consistent measure of activity of superficial muscles, if comparisons are to be made between gait data from different test days, and were better for surface electrodes than wire electrodes, irrespective of the smoothing window.

TL;DR: Results suggest that fresh vascularized grafts in the Judiciously matched or immunosuppressed recipient offer attractive clinical possibilities.

TL;DR: It is concluded that even under laboratory conditions the information gained from plain radiographs is not sufficient to accurately predict the strength of a healing fracture.

TL;DR: There was a significant reduction of bone strength with the distance from the subchondral resection surface, and this reduction was most pronounced at the high strength areas.

TL;DR: The results demonstrate that accurate measurements of three‐dimensional carpal‐bone motions are feasible by using an adequately refined roentgen‐stereophotogrammetric system and can serve as a database for future developments of functional wrist‐joint models.

TL;DR: Adult rabbit articular cartilage was prepared for scanning electron microscopy using glutaraldehyde fixation, enzymatic removal of proteoglycan, dehydration in ethanol, cryofracture in liquid nitrogen, and criticalpoint drying, and enzymes were effective in fixed material.

TL;DR: The results show that a dose‐response curve for capacitive coupling and fracture healing exists and that a 220 mV, 250 μA, 60 kHz applied electrical signal is the most effective signal for fracture stimulation in this model.

TL;DR: Measurements of myoelectric activities in 11 young men during performance of 19 isometric tasks in flexed positions found that whether or not flexion‐relaxation occurs, large trunk flexions load the spine heavily.

TL;DR: The existence of significant age‐related structural differences in articular cartilage proteoglycans is demonstrated and form the basis for future study of the mechanisms responsible for these differences.

TL;DR: Three 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.

TL;DR: In mature beagle dogs EHDP proved to have dose‐dependent and reversible inhibitory effects on secondary fracture healing, and mineralization activity activity appeared totally disrupted at the higher dosage level.

TL;DR: 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 osteOarthritis.

TL;DR: Based on stress data from finite element method (FEM) models, an analytical “closed‐form” model of the local pin‐bone configuration in long‐bone fracture fixation is developed and is relatively simple and useful for routine applications in combination with clinical studies and animal experiments.

TL;DR: In general, sodium morrhuate injected tendons were larger in diameter and contained more cells, smaller collagen fibrils, increased water and amino sugar content, and reduced hydroxyproline content compared with their contralateral controls.

TL;DR: The findings demonstrate the sensitivity of hip contact pressures and stresses to imposed boundary conditions and indicate that care should be taken to simulate anatomic conditions in experimental and theoretical studies.

TL;DR: Newly synthesised (35S)‐proteoglycans extracted from cartilage explants from osteoarthitic joints whether examined 3 weeks, 3 months, or 6 months after surgery were larger than those from corresponding normal cartilage.

TL;DR: These studies provide the first experimental evidence that a metabolic response of discs in a fused segment may be accompanied by the biosynthesis of a new PG population whose structure is similar to that present in immature tissues.

TL;DR: Physiologically moist bone and dry bone behave differently when tested for electrical response to cantilever bending, and voltages generated in the same specimen in each of the two states via the same testing procedure are characterized.

TL;DR: The results suggest that in articular cartilage the proteoglycan‐collagen interaction may be an important mechanism for controlling the partition of water between a freely exchangeable space and a space allowing no fluid exchange.

TL;DR: Only the region of the medial tibial cartilage that was unprotected by the meniscus was affected, showing increased water content, loss of superfical cells, and a decrease in orientation of the glycosaminoglycans, whereas the birefringence of the collagen was markedly increased: this may be a useful indicator of early osteoarthritic changes.

TL;DR: There was a strong correlation between radiographic and histomorphometric callus sizes, which indicate different properties of the healing bone.

TL;DR: The results indicate that previous finite element models of prosthetic tibial components have overestimated the structural contribution of the metaphyseal cortical shell by a factor of approximately 6.5.

TL;DR: The results suggest that OA, growth plate, and even normal articular cartilage all have the potential to undergo calcification as long as both phosphate and pyrophosphate ions can be generated at sufficiently high levels.

TL;DR: Results of the implanted numeral component models indicated that the use of a prosthesis with bone ingrowth along the stem would cause marked stress shielding proximally whereas the useof implants with porous ingrowth only on the underside of the humeral head replacement produced stress fields more similar to the normal humerus.