Amis, "The influence of tibial prosthesis design features on stresses related to aseptic loosening and stress shielding
", Journal of Mechanics in Medicine and Biology, 11(1), 55-72, (2011).
Importantly, CFR-PEEK can result in a modulus closely matched to that of cortical bone, and is shown to encourage load sharing and minimize stress shielding
, necessary for healthy bone.
(1,2) The aim is to provide a physiological force transmission into the calcar area in order to prevent stress shielding
and subsequent aseptic loosening.
They concluded that using FGM in the design of cementless hip stem solves the problem of stress shielding
as well as decreases the interface shear stress between the implant and femur.
It might potentially be more optimal in minimizing the bone stress shielding
However, after the implant is inserted, the load equilibrium is disturbed, new stress redistribution occurs and this may cause stress shielding
phenomenon [1, 2, 3].
Peak contact pressure and stress shielding
effect are two biomechanical parameters that have critical importance in success of TKR.
The collared SMP implant gives near about 62% stress shielding
in proximal zone.
The stresses observed in the cortical bone were below the reported ultimate strength for cortical bone under compression (approximately 200 MPa)  and reportedly below the fatigue strength for cortical bone, quoted as 40-80 MPa @[10.sup.7] cycles  but there are long-term concerns regarding the combined action of cyclic joint forces and the stress shielding
effect in the femur.
in the bone tissue was found to occur with the hip hemi-resurfacing prosthesis considered in this study.
: This is an important phenomenon as the metals are a decade order stiffer (modulus of elasticity) compared to bone and bone is 5-6 times stiffer than bone cement, the major stress is shared by the stiffer materials leaving the bone shielded from the stress flow, which may go below the physiological level of stress leading to disuse osteoporosis and failure of the construct.
Most popularly used metals and metal alloy implants cause severe stress shielding
at the proximal part of the femur and the interface stress is concentrated at the distal tip of the prosthesis giving rise to mid thigh pain.