Comparison of Fracture Resistance Using Two Different Major Cemented Stems in Osteoporotic Bone Models

Background: Periprosthetic hip fractures (PPFs) are one of the major complications in total hip arthroplasty (THA). Therefore, it is important to identify the mechanism of fracture resistance in THA. This study aimed to clarify the differences in fracture torque and fracture type analysis between 2 different types of cemented stems. Methods: We conducted biomechanical testing of bone analogues using 6 cemented stems of 2 different types with osteoporotic bone model: Anterior minimally invasive surgery (AMIS)-K and Charnley-Marcel-Kerboull (CMK) stem. Experienced surgeons implanted each of these types of stems into 6 bone analogues, and the analogues were compressed and internally rotated until failure. Torque to fracture and fracture type were recorded. Results: There was no significant difference in fracture torque of AMIS-K stem, compared to the CMK stem (p = 0.94). The AMIS-K stem showed 1 comminuted oblique fracture of Vancouver type B2 and 5 fractures of type C at the tip of the stem. The CMK stem showed 5 comminuted oblique fracture of Vancouver type B2 and 1 type C at the tip of the stem. Conclusion: AMIS-K stem demonstrated comparable fracture resistance to CMK stem in an osteoporotic model.