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

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.