Comparing the stability of a novel h-shaped bone plate and commercial endosteal plating systems in hallux valgus...

It is common for physicians to opt for surgical correction of hallux valgus deformities using implants, but post-operative complications are frequently reported. A novel h-shaped plate developed by the authors offers both endosteal and lateral fixation, helping to resist displacement in multiple directions. This study aims to assess the mechanical properties and stability of the h-shaped plate in comparison to various commercially available endosteal plating systems in a simulated hallux valgus correction model using finite element analysis.

Finite element models of four different endosteal plates were developed and used to simulate a hallux valgus correction. The distal end of the metatarsal in each model was loaded at 87.5 N, which is the maximum load experienced during cyclic testing. The load was applied in various directions to simulate different metatarsal movements, including plantar flexion, dorsiflexion, abduction, and adduction of the first metatarsal bone. The mechanical properties and stability of each model was recorded for comparison.

When placed under dorsal-to-plantar loading, the model with a h-shaped plate was the most stable of all models, with a displacement of 0.278 mm, plate stress of 429.51 MPa, and screw stress of 294.97 MPa. Under medial-to-lateral loading, the model with a h-shaped plate demonstrated the lowest displacement of 0.152 mm, and plate and screw stresses of 254.27 MPa and 195.40 MPa, respectively.

For stabilizing distal chevron osteotomies, the h-shaped bone plate showed greater resistance to displacement in the dorsal-to-plantar and medial-to-lateral directions than the commercially available implants evaluated in this study. The h-shaped plate also presented a lower risk of screw pull-out, which helps to maintain bone alignment postoperatively.