Biomechanical comparison of 2.4-mm locking compression plating radial head plate and tripod fixation in Mason type III radial head fractures: a human cadaveric study.

Abstract

Proximal radius fractures, particularly Mason type III, represent a challenge in elbow surgery because of their complexity and impact on joint function. Using the conventional radial neck plate is a reliable treatment option; however, it can cause soft tissue irritation and restricted range of motion. A novel tripod fixation approach, using 3 crossed screws, should minimize such complications and preserve range of motion. This study aims to compare the biomechanical competence of conventional radial neck plating using an locking compression plate Radial Head Neck Plate 2.4 mm (Johnson&Johnson MedTech) vs. tripod fixation in a Mason type III fracture model. Sixteen paired human cadaveric radii underwent a standardized osteotomy to simulate a transverse neck fracture with an additional 50:50 head split component and were assigned to 2 groups: Plate group, fixed with a conventional radial neck plate with 2 additional canulated headless compression screws (HCSs), and Tripod group, stabilized with tripod fixation (3 cannulated 40-mm HCSs) and 2 additional HCSs. Biomechanical tests assessed stiffness in anteroposterior and mediolateral bending, axial compression, pronation, and supination. No significant differences were found in stiffness across the comparisons: mediolateral bending: Plate, 91 ± 47 N/mm, and Tripod, 195 ± 132 N/mm (P = .067); anteroposterior bending: Plate, 168 ± 105 N/mm, and Tripod, 145 ± 108 N/mm (P = .670); axial compression: Plate, 643 ± 337 N/mm, and Tripod, 642 ± 188 N/mm (P = .998); pronation: Plate, 0.15 ± 0.10 Nm/°, and Tripod, 0.23 ± 0.23 Nm/° (P = .336); and supination: Plate, 0.17 Nm/°, and Tripod, 0.25 ± 0.21 Nm/° (P = .351). Cycles to failure under axial compression were recorded, with the Plate group showing 4,078 ± 3,173 cycles and the Tripod group 4,763 ± 5,288 cycles, P ≥ .4. Load to failure was noted at 586 ± 222 N for the Plate group and 789 ± 337 N for the Tripod group, P ≥ .4. From a biomechanical perspective, the tripod technique with 2 additional HCSs showed comparable performance compared with plate fixation with 2 additional HCSs in transverse radial neck fractures with an additional head split component. With potentially less soft tissue irritation and necessary secondary hardware removal, the tripod technique seems to be a valid alternative to conventionally used plate osteosynthesis techniques. However, further randomized clinical trials are needed to fully evaluate its clinical value.