Biomechanical Properties of 3-Dimensional Printed Volar Locking Distal Radius Plate: Comparison With Conventional Volar Locking Plate

Abstract

Purpose This study evaluated the biomechanical properties of a new volar locking plate made by 3-dimensional printing using titanium alloy powder and 2 conventional volar locking plates under static and dynamic loading conditions that were designed to replicate those seen during fracture healing and early postoperative rehabilitation.

Methods For all plate designs, 12 fourth-generation synthetic composite radii were fitted with volar locking plates according to the manufacturers’ technique after segmental osteotomy. Each specimen was first preloaded 10 N and then was loaded to 100 N, 200 N, and 300 N in phases at a rate of 2 N/s. Each construct was then dynamically loaded for 2,000 cycles of fatigue loading in each phase for a total 10,000 cycles. Finally, the constructs were loaded to a failure at a rate of 5 mm/min.

Results All 3 plates showed increasing stiffness at higher loads. The 3-dimensional printed volar locking plate showed significantly higher stiffness at all dynamic loading tests compared with the 2 conventional volar locking plates. The 3-dimensional printed volar locking plate had the highest yield strength, which was significantly higher than those of 2 conventional volar locking plates.

Conclusions A 3-dimensional printed volar locking plate has similar stiffness to conventional plates in an experimental model of a severely comminuted distal radius fracture in which the anterior and posterior metaphyseal cortex are involved.

Clinical relevance These results support the potential clinical utility of 3-dimensional printed volar locking plates in which design can be modified according the fracture configuration and the anatomy of the radius.