RESUMEN
Objective: This study introduced the structural features of the Three-Dimensional Proximal Femoral Nail (3DPFN), a patented invention, and highlights its advantages in treating intertrochanteric fractures of the femur. Furthermore, biomechanical comparative experiments validated the biomechanical performance of 3DPFN in treating Evans-Jensen type IV intertrochanteric fractures. Methods: Evans-Jensen type IV intertrochanteric fracture models were created using artificial femurs produced by the American company Sawbone. From January to April 2022, the experimental group was fixed with 3DPFN, while the control group was fixed with the Proximal Femoral Nail Antirotation (PFNA), simulating the loading conditions in the human body. Axial static ultimate pressure tests and dynamic fatigue tests were conducted. The recorded parameters included the maximum load-bearing capacity under axial load, the maximum number of cycles, and the maximum load before failure. Results: Static ultimate pressure tests showed that the static ultimate load in the 3DPFN group was 2532.67±49.20N, whereas in the PFNA group, it was 2240.00±84.35N, with a significant difference between the two groups (P < .05). Dynamic fatigue tests revealed that the maximum number of cycles in the 3DPFN group was 86372.67±4762.59 cycles, while in the PFNA group, it was 8606.67±606.05 cycles, also showing a significant difference (P < .05). Dynamic fatigue tests further indicated that the fatigue limit load before failure in the 3DPFN group was 1664.00±78.27N, whereas in the PFNA group, it was 799.33±63.52N. Again, there was a significant difference between the two groups (P < .05). Conclusion: In both static compression and fatigue tests, 3DPFN exhibits significant biomechanical advantages over PFNA. This suggests that 3DPFN may be an excellent choice for the treatment of intertrochanteric fractures of the femur and holds further research value for development. Future studies may involve clinical trials to validate and refine the 3DPFN design based on the observed results and promote the advancement of orthopedic implant technology.
RESUMEN
BACKGROUND: Tibial shaft fractures account for approximately 15% of long bone fractures. Locked plates with minimally invasive plate osteosynthesis techniques are used widely by surgeons. The purpose of this study is to investigate the impact of factors meaning the plate length, fibula integrity, and placement of the plate on the stability of tibial shaft fracture fixation. METHODS: A finite element model of the tibial shaft fracture was built. An axial force of 2500 N was applied to simulate the axial compressive load on an adult knee during single-limb stance. The equivalent von Mises stress and displacement of the fractured ends were used as the output measures. RESULTS: In models with plates on the lateral side of the tibia, displacement in models fixed with a 12-hole plate showed the smallest value. In models with plates on the medial side of the tibia, displacement in models fixed with 14-hole plate showed the smallest value. The peak stress of plates implanted on the medial side of the tibia was higher than that of plates on the lateral side. The peak stress and the displacement of models involved with the fibula were lower than that of models without fibula, regardless of the length or location of plates. CONCLUSIONS: For models with plates on the medial side of the tibia, the 14-hole plate is the best choice in terms of stability. While for models with plates on the lateral side of the tibia, the 12-hole plate demonstrated the optimal biomechanical stability. The integrity of the fibula improves the anti-vertical compression stability of the construct. The peak stress of plates implanted on the medial side of the tibia was higher than that of plates on the lateral side, which indicated that the construct with medially implanted plate has a higher risk of implant failure.
