Novel approach for designing a low weight hip implant used in total hip arthroplasty adopting skeletal design techniques.

Aseptic loosening is the major cause of failure of hip implants after total hip arthroplasty. Stress shielding of the femur is known to be the principal factor involved in the aseptic loosening of hip implants. Solid stems are found to have a greater rigidity; therefore, they transfer less load proximally, which results in greater stress shielding of the proximal femur.

Design optimization of skeletal hip implant cross-sections using finite-element analysis.

The major causes for revision surgery after total hip arthroplasty are aseptic loosening, dislocation, wear, design factors, stress shielding on the bone, and mechanical and biological factors. A material with toughness and high wear properties is essential for a good hip implant because these implants fail due to design. Stress shielding is found to be the major cause for the failure of hip implants, and can lead to the implant needing to be replaced or revised, which is painful for the patient and costly for the health care industry.