Polymethylmethacrylate (PMMA) Augmentation Enhances the Mechanical Characteristics of Midfoot Beam Constructs in Charcot Neuroarthropathy Cadaver Model

• Published in: Foot & ankle international 2024-06, Vol.45 (6), p.648-655
• Main Authors: Pattisapu, Naveen, Huang, Dave T., Porter, Giselle, Owhonda, Rebisi, Charlton, Timothy, Gross, Christopher, Thordarson, David, Metzger, Melodie F.
• Format: Article
• Language: English
• ISSN: 1071-1007; 1944-7876
• DOI: 10.1177/10711007241237804

Background: Even with the best conservative care, patients with Charcot neuroarthropathy (CN) of the foot and ankle often ulcerate, increasing their risk of infection, amputation, and death. Surgical fixation has been associated with risk of recurrent ulceration, potentially due to poor bone quality prone to recurrent deformity and ulceration. We propose midfoot beam reconstruction with PMMA augmentation as a novel means of improving fixation. Methods: A protocol was developed to create characteristic CN midfoot fragmentation both visually and fluoroscopically in each of 12 matched-pair cadaveric feet. Afterward, the pairs were divided into 2 groups: (1) midfoot beam fusion surgery alone, and (2) midfoot beam fusion surgery augmented with PMMA. A solid 7.0-mm beam was placed into the medial column and a solid 5.5-mm beam was placed across the lateral column. In the PMMA group, 8 to 10 mL of PMMA was inserted into the medial column. The hindfoot of each specimen was potted and the metatarsal heads were cyclically loaded for 1800 cycles, followed by load to failure while load and displacement were continually recorded. Results: One specimen in the beam alone group failed before reaching the 1800th cycle and was not included in the failure analysis. The midfoot beam only group demonstrated greater mean displacement during cycle testing compared with the PMMA group, P