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Biomedical subjects

N J Holm

Publications and source records attributed to N J Holm.

10 recordsLinked to original sources
PubMed1981

The development of a two-dimensional stress-optical model of the os coxae.

On the basis of a previous analysis of the internal stress pattern of the os coxae two types of two-dimensional models for stress-optical analysis are developed and the experimental set-up and procedure are described. The models may be used in an analysis of the principal stress pattern changes following the insertion of various types of hip prostheses.

Hip↗
PubMed1980

The internal stress pattern of the os coxae.

The stress pattern of the os coxae was evaluated from the trabecular patterns and the theoretically predicted stresses based on the principles of Wolff's law. A good correlation between the expected stress situation and the trabecular pattern was observed.

Biomechanical Phenomena↗
PubMed1980

The formation of stress by acrylic bone cements during fixation of the acetabular prosthesis.

The forces developed by acrylic cement during the final phase of polymerization under conditions that simulate the cement of the acetabular prosthesis are evaluated. Calculations show that forces of 500-1100 N may be reached in a three-point fixational system. The importance of the dimensions of the plastic and the bone and the relevance of the E-moduli are discussed.

Acetabulum↗
PubMed1980

The relaxation of some acrylic bone cements.

The creep and relaxation of acrylic cements during conditions simulating the conditions in the acetabulum have been examined. CMW and Simplex were found to reach stresses of about 10 N/cm2 after 1 year whereas Palacos had lost most of its stress after 6 weeks.

Acetabulum↗
PubMed1977

The modulus of elasticity and flexural strength of some acrylic bone cements.

The modulus of elasticity and flexural strength were measured for three bone cements, CMW Bone Cement, Surgical Simplex, and Palacos R. with various additions and prepared as in actual use. A distinct afterpolymerization was demonstrated in all three brands. The addition of blood lowered the E-modulus wheras radio-opaque media seemed to render them somewhat stiffer. The rupture values demonstrated the inhomogeneity of the final product in all three brands. The possible clinical significance of the findings is discussed.

Bone Cements↗