The effect of bone marrow on the mechanical behavior of porcine trabecular bone

Abstract

Bone marrow plays an important role on the mechanical properties of trabecular bone. Its effect on the mechanical properties of porcine trabecular bone is studied in this paper. Uniaxial compression at a low strain rate (0.01 s −1 to 20% strain) and stress relaxation tests (600 s at 85, 70 and 55% of the max. load) were done on 90 different femur samples. Half the samples were treated to extract the bone marrow. The average pore size of the trabecular network was 0.280±0.056 mm. Higher values of elastic modulus (37%), 0.2% yield stress (48%), maximum stress (39%), strain at maximum stress (54%), and toughness (300%), were found for the samples which had the bone marrow extracted and were saturated with a saline solution. A linear relation between the applied load and the relaxation stress of s s = 0.76 rel o was found, which means that the trabecular bone behaves as a linear viscoelastic material. A mathematical approximation of the relaxation response was done using a Kohlrausch-Williams-Watts model for viscoelastic materials. Results show that it is essential to consider the viscoelastic behavior that the marrow has on the mechanical properties of the trabecular bone. The effect that the bone marrow has on the stress relaxation was found to be negligible at low strain rates and in the elastic stage of deformation.

The role of bone marrow on the mechanical properties of trabecular bone: a systematic review

“…Thirty-seven clearly described the background, purpose, and objectives of the study in the abstract. No study included the sample size calculation, and only two studies addressed the missing data [ 14 , 21 ]. Furthermore, the large heterogeneity and lack of randomized controlled trials made it impossible to carry out a meta-analysis.…”

“…Compression tests are used to determine how a material reacts when compressed by measuring basic parameters including elastic modulus, maximum compressive stress, average compressive stress, yield stress, toughness, etc. [ 13 , 14 ]. Previous studies have investigated the role of bone marrow on the compression properties of trabecular bone, both in vitro experiments and computer model simulations.…”

“…Concerning this subject, previous studies have been conducted not only with in vitro experiments [ 11 – 14 ], but also with computer model simulations [ 15 – 17 ]. However, in practice, it is hard to quantify the contribution of bone marrow to the mechanical behavior of trabecular bone since it is highly reliant on the experimental setup and conditions [ 13 , 14 ]. To date, there is a lack of comprehensive research on this topic.…”

Selected mechanical properties of human cancellous bone subjected to different treatments: short-term immersion in physiological saline and acetone treatment with subsequent immersion in physiological saline

“…Apart from that, several studies have reported that the presence of bone marrow has a significant effect on the mechanical properties of cancellous bone [ 6 , 8 , 9 ]. Thus, mechanical properties will be variable depending on whether the samples are tested with or without marrow.…”

“…Hence, it was unclear if the changes in mechanical properties after acetone treatment could be reversed by subsequent immersion in physiological saline. Moreover, current studies investigating the influence of bone marrow removal on the mechanical properties of cancellous bone are few and mostly limited to animal bones [ 8 ] or human bone from a single anatomical site [ 17 ]. Due to the varying loads, the density and microstructure of human cancellous bone differ from those of animals, resulting in some variability in mechanical properties [ 18 ].…”