Biomechanical Comparison of Intramedullary Beaming and Plantar Plating Methods for Stabilizing the Medial Column of the Foot: An In Vitro Study.

Abstract

Charcot neuroarthropathy often results in a rocker-bottom foot deformity, which leads to ulceration, infection, and amputation. Surgical techniques to reconstruct the medial column include intramedullary beaming and plantar plating, with disagreement regarding which approach provides a stronger construct with superior stability and fixation. The objective of the present cadaveric study was to compare the construct rigidity and strength of beaming and plantar plating of the medial column of 5 paired bilateral feet. Cannulated titanium beams and plates were implanted in the right and left feet, respectively. The specimens underwent interval testing to generate load-displacement and load-strain curves, cyclic loading at low loads, and then were loaded to failure. The beamed and plated specimens had statistically similar stiffness (p = .80) with a mean of 11.1 ± 3.9 N/mm and 11.3 ± 5.9 N/mm, respectively. The beamed and plated specimens had a statistically similar mean strain of -164 ± 75.1 µε and -208 ± 87.8 µε on the dorsal (p = .45) and 92 ± 90.4 µε and 221 ± 100.5 µε on the plantar (p = .08) surfaces of the first metatarsal. Three beamed specimens failed from talus fracture (60%), and 2 beams plastically deformed (40%). Two plated specimens failed from talus fracture (40%), and 3 experienced screw pullout (60%). The beamed and plated specimens withstood a mean load to failure of 234 ± 111.4 N and 140 ± 68.9 N, respectively, with the difference statistically significant (p = .04). Overall, beaming was more robust than plantar plating, because it was less sensitive to specimen size and bone quality.