🔍 Key Findings
- In an ex vivo study of 20 canine femur pairs, implantation of a novel hip resurfacing arthroplasty (HRA) prosthesis reduced maximum load (ML) by 22% and load at collapse (LC) by 27% vs. intact controls (p ≤ 0.05).
- Displacement at maximum load (DML), displacement at collapse (DC), and stiffness (k) were not significantly different between prosthesis and control groups.
- Both groups showed similar failure patterns, with 92% failing at the femoral neck.
- All prosthetic femurs still withstood ~6.2× body weight — exceeding estimated in vivo peak loads (~1.64× BW).
- Prosthesis positioning (neutral vs valgus) had no significant effect on biomechanical outcomes.
- Implant design preserved more metaphyseal bone stock than total hip replacement, possibly explaining the smaller load reduction compared to other short-stem prostheses.
- The press-fit cobalt–chromium design with conical stem allowed full contact and stress distribution over the femoral head/neck.
- Authors conclude the device has adequate immediate biomechanical strength for clinical use, though long-term in vivo studies are needed.
