Purpose: Dynamic hip screw (DHS) plate fabrication has a crucial role in success rate of surgeries for fractures of the proximal femur. Our research focuses on comparing microstructure and mechanical properties of DHS plates fabricated through two distinct processes. We aimed to compare the mechanical cold-worked (CW) DHS plate versus a DHS plate that fabricated through the cold-worked hot-forged (CWH) DHS plate. Methods: The CW and CWH DHS plates had similar topology, however, tested under different loading scenarios. To make the results comparable, the test for the CW DHS plate was simulated and validated utilizing the finite element modeling (FEM) approach. Then, the model (i.e., the CW DHS plate) was analyzed applying the loading scenario of the CWH DHS plate test. Finally, the results of the FEM analysis for CW and the actual test for CWH DHS plates including compression bending stiffness/strength and proof load were compared. Furthermore, the chemical combination of the two plates was analyzed to investigate if they meet the requirements for ASTM F138 standard. Results: Our analysis showed the amount of “Proof Load” and “Compression Bending Strength” of the CWH DHS plate significantly improved by ∼87% in comparison with the CW DHS plate that both fabricated with ASTM F138 material. On comparison between their grain sizes, the CWH DHS plate has a finer grain size (∼55% smaller than CW DHS plate) which leads to larger yield stress. Conclusion: Although the cold-working process according to ASTM F138 leads to enhance the mechanical performance of a DHS plate, adding hot-forging to the process improved the mechanical performance of DHS plate. The outcome of this study could facilitate the development of the optimal fabrication process for surgical implants which in turn will increase the long-term success rate of the relevant surgeries.

Enhancing the design of bone screw head sockets to prevent stripping and improve the torque required for smooth unscrewing is a significant challenge in orthopedic applications. This research aims to establish a quantitative methodology by integrating mechanical testing with finite element (FE) simulations to determine a safe limitation depth for the screwdriver when engaging with the hexagonal socket, thus avoiding stripped screw heads. A FE model was developed to investigate the biomechanical responses of the screw head design. Five custom-made hexagonal sockets were manufactured, and single load torsional tests were conducted to assess the mechanical performance of the screws and drivers. The results from the mechanical tests were compared with the FE simulations, demonstrating a close agreement and confirming the model’s validity. Furthermore, additional FE models were created to study the impact of manufacturing tolerances on the socket width and screwdriver width. The findings revealed that the maximum torque to failure for the four designs was lower than the margins specified in ISO 6475. Additionally, increasing the depth of the screwdriver led to higher maximum torque values. This research suggests that the technique of screw insertion, specifically the depth of the driver tool within the screw socket, holds greater importance in preventing stripped screw heads than the design and manufacturing width of the bone screw’s hexagonal socket and screwdriver. This confirms the importance of screwdriver engagement inside the bone screw socket to prevent stripped screw heads and sheds light on the added value of maximum torque prediction for future design modifications.