Caldeira et al: In Vitro Biomechanical Study of Femoral Neck Fracture Fixation with Two or Three Cannulated Screws in Dogs
Veterinary and Comparative Orthopedics and Traumatology 1, 2025

🔍 Key Findings

Design: In vitro study on cadaveric femurs (n=21) with basilar femoral neck fractures stabilized using 2 vs 3 titanium cannulated screws.

Stiffness: Control > 3-screw > 2-screw (674 > 120 > 90 N/mm).

Yield Load: 3-screw (586 N) > 2-screw (303 N); both < intact femur (2692 N).

Displacement: No difference across groups.

Complication: 3-screw technique more demanding; higher risk of cortical perforation, especially with narrow femoral necks.

Failure Mode: Dislodgement of femoral head + screw shaft bending.

Conclusion: 3 screws = stronger construct than 2 screws. Clinical implications need further study.