  Osteonecrosis occurs due to the loss of blood supply to the bone, leading to
spontaneous death of the trabecular bone. Delayed treatment of the involved
patients results in collapse of the femoral head, which leads to a need for
total hip arthroplasty surgery. Core decompression, as the most popular
technique for treatment of the osteonecrosis, includes removal of the lesion
area by drilling a straight tunnel to the lesion, debriding the dead bone and
replacing it with bone substitutes. However, there are two drawbacks for this
treatment method. First, due to the rigidity of the instruments currently used
during core decompression, lesions cannot be completely removed and/or
excessive healthy bone may also be removed with the lesion. Second, the use of
bone substitutes, despite its biocompatibility and osteoconductivity, may not
provide sufficient mechanical strength and support for the bone. To address
these shortcomings, a novel robot-assisted curved core decompression (CCD)
technique is introduced to provide surgeons with direct access to the lesions
causing minimal damage to the healthy bone. In this study, with the aid of
finite element (FE) simulations, we investigate biomechanical performance of
core decompression using the curved drilling technique in the presence of
normal gait loading. In this regard, we compare the result of the CCD using
bone substitutes and flexible implants with other conventional core
decompression techniques. The study finding shows that the maximum principal
stress occurring at the superior domain of the neck is smaller in the CCD
techniques (i.e. 52.847 MPa) compared to the other core decompression methods.
