Load-transfer analysis after insertion of cementless anatomical femoral stem using pre- and post-operative CT images based patient-specific finite element analysis

Trade-off between stress shielding and initial stability on an anatomical cementless stem shortening: in-vitro biomechanical study

“…This finding is consistent with those of previous biomechanical studies examining different types of femoral stems, such as anatomic, straight, custom made, short, and low modulus stems [7,16,[29][30][31][32]. The distal part of the anatomical stem is likely to support the load because of a proximal-distal mismatch (tight distal fit and fill), which may lead to proximal bone resorption and cortical hypertrophy [33]. Our results showed that in the proximal region, shortening the stem gradually promoted proximal load transfer with decreasing stem lengths.…”

Computational intelligence based design of implant for varying bone conditions

“…The human femur, approximately the proximal half of the bone, was reconstructed in 3D, based on CT data of a female subject, aged 55 years, taken in DICOM format (512 × 512 pixels per slice, pixel size: 0.6445 mm and slice thickness: 1 mm), by means of a medical image‐processing software MIMICS® 10.0 (Materialize NV, Leuven, Belgium). The location‐specific bone properties were calculated based on voxelwise X‐ray attenuation, given in Hounsfield unit (HU).…”

“…Aseptic loosening of the implant, because of periprosthetic bone resorption, is regarded as a vital cause of failure of total hip replacement (THR), often leading to revision surgeries and complicacy of the condition . Among the causes of periprosthetic bone resorption is the natural response of the bone toward stress shielding of the proximal portion of the femur, as the implant materials, mainly alloys, are much stiffer than the bone. Moreover, implantation creates formation of new interface (metal‐bone interface for uncemented implantation) through which load transmits, creating alterations of the direction and magnitude of the load vectors and the stress profile within the bone .…”

“…Among the causes of periprosthetic bone resorption is the natural response of the bone toward stress shielding of the proximal portion of the femur, as the implant materials, mainly alloys, are much stiffer than the bone. Moreover, implantation creates formation of new interface (metal‐bone interface for uncemented implantation) through which load transmits, creating alterations of the direction and magnitude of the load vectors and the stress profile within the bone . There is difference in strain and deformation among the bone and implant metal, upon physiological loading, causing the implant to press the bone on some location while it tends to detach from some other location, and thus, stress shielding gets further augmented.…”

On the choice of the thickness of the cement mantle in cemented hip arthroplasty

“…By virtue of the FEM, it is possible to avoid difficulties associated with the use of analytical methods for calculation of the stress-strain state of biomechanical systems and, most importantly, to obtain high accuracy of results (Yamako et al, 2014).…”