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Biomedical subjects

K G Heiple

Publications and source records attributed to K G Heiple.

At least 55 records · Page 3Linked to original sources
PubMed1978

A fluted femoral intramedullary rod. Biomechanical analysis and preliminary clinical results.

An intramedullary rod for the femur was designed and compared with rods commonly used. Its bending strength was increased 40 to 80 per cent and its torsional rigidity was increased 230 to 3,000 per cent compared with the other devices tested. In forty patients with traumatic and pathological fractures and osteotomies of the femur, excellent fixation was achieved and very early weight-bearing was possible. In all fresh fractures and non-infected non-unions, union occurred very promptly and bone-grafting was not required in most instances. The stregth and rigidity of the device made it exceptionally useful for non-unions, pathological fractures of the femur, and resection-fusions of the knee.

Adolescent↗
PubMed1977

Turnover of collagen in the adult rat after denervation.

Unilateral denervation of the hind limb in a group of adult rats prelabeled with radioactive proline induced a significant turnover of collagen in tendons, ligaments, menisci, and bones. After two or three months of disuse, there were significant losses (15 to 29 per cent) of old collagen from the four structures studied. Dilution of the radioactivity of the old collagen with new collagen involved partial to complete replacement of 3 to 20 per cent. The incomplete replacement of destroyed collagen with new collagen resulted in a net decrease of collagen mass ranging from 5 to 14 per cent. A significant turnover of collagen in two-year-old rats that showed little loss in collagen mass means that the new collagen produced would have fewer cross-links and would probably be weaker than the old, mature collagen.

Animals↗
PubMed1976

The biomechanical analysis of bone strength: a method and its application to platycnemia.

Traditional methods of bone analysis (both metric and topographic) are restricted to external characters. Special distribution of material is, however, equally critical to an understanding of a bone's function. Dynamic testing to determine whole bone strength can only be performed on fresh specimens. Methods for the calculation of both bending and torsional strength of other specimens (such as preserved or fossil bones) are developed in this paper. In order to illustrate the methods, the functional significance of tibial shaft cross sectional variation is investigated.

Biomechanical Phenomena↗
PubMed1975

Contribution of collagen and mineral to the elastic-plastic properties of bone.

Tension testing of wet bovine haversian cortical bone demonstrated marked plastic behavior. Progressive surface decalcification of this bone with dilute hydrochloric acid resulted in progressive decreases in the tension yield point and the ultimate stress with no change in the yield strain or ultimate strain unless decalcification was complete. The slope of the plastic region remained identical throughout decalcification. These findings are consistent with an elastic-perfectly plastic model for the mineral phase of bone tissue in which the mineral contributes the major portion of the tension yield strength. The slope or stiffness of the plastic region of the stress-strain curve is a function only of the properties of collagen, which itself plays a minor role in the tension yield strength of bone.

Animals↗
PubMed1972

Primate phylogeny and immunological distance.

Recalculation of the time of divergence of the Pongidae and Hominidae after correction of immunological distance by inclusion of generation length yields minimum dates of approximately 14 million years ago.

Adaptation, Physiological↗