Numerical investigation of the effect of bone cement porosity on osteoporotic femoral augmentation

Abstract

Femoroplasty is the injection of bone cement into the proximal femur, enhances the bone load capacity, and is typically applied to osteoporotic femora. To minimize the required injected volume of bone cement and maximize the load capacity enhancement, an optimization problem must be solved, where the modulus of elasticity of the augmented bone is a key element. This paper, through the numerical investigation of a fall on the greater trochanter of an osteoporotic femur, compares different ways to calculate this modulus and introduces an approach, based on the concept of bone cement porosity, which provides results statistically similar to those obtained with other considerations. Based on this approach, the present paper quantifies the correlation between degree of osteoporosis and optimum volume of bone cement. It concludes with an exhaustive search that reveals the effect of the bone cement porosity on the optimum volume of PMMA, for various combinations of the frontal and transverse angles of the fall on the greater trochanter.

Study on the angiogenesis ability of Polymethyl methacrylate-mineralized collagen/Mg-Ca composite material in vitro and the bone formation effect in vivo

“…VEGF is an improtant proangiogenic factor, and it can induce the expression of the matrix collagenase and other factors in the endothelial cells, thereby changing the extracellular matrix and promoting the growth of the vascular endothelial cells. 50,51 This result confirm that not only the Mg matrix in the composites can promote the expression of VEGF, but the the addition of reinforcement materials also contribute to the VEGF secretion of HUVECs. In conclusion, these data indicate that PMMA-nHAC/Mg-Ca group, compared with other groups, has good angiogenesis ability, which can not only promote the proliferation and adhesion of HUVECs, but also enhance the angiogenesis ability of Mg matrix, which is more conducive to VEGF secretion of HUVECs.…”

Biomechanical role of osteoporosis in the vibration characteristics of human spine after lumbar interbody fusion

“…[4][5][6] Osteoporosis is the most common challenge for lumbar interbody fusion since most patients requiring lumbar interbody fusion are the elderly with osteoporosis. [7][8][9] Due to the fixator in the vertebral bodies, loss of bone density and osteoporosis occurred in the fusion bone. 10,11 Osteoporosis is closely related to fusion outcomes and complications such as degeneration disease, pedicle screw failure, subsidence, and vertebral fracture.…”

“…The bilateral pedicle screw fixation system was usually combined with lumbar interbody fusion to ensure the stability of the lumbar spine and relieve the low back pain 4‐6 . Osteoporosis is the most common challenge for lumbar interbody fusion since most patients requiring lumbar interbody fusion are the elderly with osteoporosis 7‐9 . Due to the fixator in the vertebral bodies, loss of bone density and osteoporosis occurred in the fusion bone 10,11 .…”