Stress Changes in the Canine Radius after Locking Plate Fixation Using Finite Element Analysis

Area of Science:

• Veterinary Orthopedics
• Biomechanical Engineering
• Finite Element Analysis

Background:

• Locking plates (LP) are used in fracture repair.
• Understanding stress distribution beneath implants is crucial for bone healing and implant longevity.
• Finite Element Analysis (FEA) provides a method to simulate biomechanical stresses.

Purpose of the Study:

• To evaluate stress changes in canine radii beneath locking plates (LP) using FEA.
• To compare stress distribution with different LP placements relative to the radial surface.

Main Methods:

• Harvested radii from eight dogs were scanned using computed tomography (CT).
• Radii were analyzed using FEA software with three groups: no plate, LP 1mm above, and LP 3mm above the surface.
• Equivalent, maximum, and minimum principal stresses and minimum principal strain were measured beneath the plate.

Main Results:

• In shell elements, LP placement significantly reduced maximum principal stress compared to the intact group.
• In solid elements, LP placement increased equivalent stress but decreased maximum principal stress compared to the intact group.
• Stress reduction beneath the plate was observed with LP placement.

Conclusions:

• LP placement can reduce tension stress on the radius cortical bone.
• Observed stress changes may be linked to implant-induced osteoporosis and bone formation.
• FEA is a valuable tool for analyzing biomechanical effects of orthopedic implants.