The influence of hip revision stem spline design on the torsional stability in the presence of major proximal bone defects

The study evaluates how hip revision stem design influences torsional stability in patients with significant bone loss. Specifically, it compares an established stem (Reclaim®) with a prototype featuring two sets of splines, one being less prominent. Five pairs of human femurs were used in the study, simulating large bone defects, common for revision surgeries. The prototype stem showed improved contact with the femoral cortex, resulting in 54% more cortical contact area and significantly higher torsional stability (35.2 Nm vs. 28.2 Nm). Although both stems demonstrated similar implantation characteristics, the prototype required slightly more force for proper seating. No significant differences in implant depth or angular misalignment during implantation were observed between the two designs. The study concluded that adding less prominent splines can enhance contact between the implant and bone, providing greater resistance to torsional loads and potentially improving the long-term success of hip revision surgeries.

https://doi.org/10.1371/journal.pone.0291599