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 a mechanism for fracture resistance in THA. This study aimed to clarify the differences in fracture torque and fracture type analysis between two different types of cemented stems.

Methods

We conducted biomechanical testing of bone analogues using six cemented stems of two different types with osteoporotic bone models: Anterior minimally invasive surgery (AMIS)-K and Charnley-Marcel-Kerboull (CMK) stems. Experienced surgeons implanted each of these types of stems into six 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 one comminuted oblique fracture of Vancouver type B2 and five fractures of type C at the tip of the stem. The CMK stem showed five comminuted oblique fracture of Vancouver type B2 and one of type C at the tip of the stem.

Conclusion

The AMIS-K stem demonstrated comparable fracture resistance to the CMK stem in an osteoporotic model.