Medial Column Consequences of Graft Shape in Evans Osteotomy: A Cadaveric Biomechanical Study
Description
Adult-acquired flatfoot deformity (AAFD) is marked by collapse of the medial longitudinal arch, hindfoot valgus, and forefoot abduction, most often due to posterior tibial tendon dysfunction. The Johnson and Strom classification describes progression from tendon inflammation (Stage I) to ankle involvement with deltoid insufficiency (Stage IV) and remains widely used to guide management.
For Stage II AAFD, the Evans calcaneal osteotomy is a common lateral column lengthening (LCL) technique. The osteotomy, placed just proximal to the calcaneocuboid joint, is lengthened with a graft to restore the medial longitudinal arch and correct peritalar subluxation. While effective, Evans osteotomy may alter joint pressures, particularly at the calcaneocuboid joint. Graft size and shape can influence the degree of correction and load distribution.
A cadaveric flatfoot deformity will be created by partial transection of the spring and talocalcaneal ligaments with release of the talonavicular joint. A 10 mm calcaneal osteotomy will then be performed proximal to the calcaneocuboid joint. Rectangular and triangular 3D-printed grafts, designed in Autodesk Tinkercad and printed with Ideamaker, will be inserted for lengthening. Tekscan sensors will measure contact pressures in the subtalar and talonavicular joints.
Rectangular grafts provide stronger correction but increase lateral overload, while triangular grafts yield more balanced pressure with less correction. Our cadaveric findings support these trends and highlight previously undiscussed changes in medial column pressures. Our purpose is to determine how these changes indicate or contraindicate the use of further surgical and osseous procedures on the medial column.
Citation Information
Mathur, Naman; Bernard, Benjamin; Lu, Angel; Dikis, Ashley; and Grambart, Sean T., "Medial Column Consequences of Graft Shape in Evans Osteotomy: A Cadaveric Biomechanical Study" (2026). Office of Research DMU Research Symposium. 29.
https://digitalcommons.dmu.edu/researchsymposium/2025rs/2025abstracts/29
Medial Column Consequences of Graft Shape in Evans Osteotomy: A Cadaveric Biomechanical Study
Adult-acquired flatfoot deformity (AAFD) is marked by collapse of the medial longitudinal arch, hindfoot valgus, and forefoot abduction, most often due to posterior tibial tendon dysfunction. The Johnson and Strom classification describes progression from tendon inflammation (Stage I) to ankle involvement with deltoid insufficiency (Stage IV) and remains widely used to guide management.
For Stage II AAFD, the Evans calcaneal osteotomy is a common lateral column lengthening (LCL) technique. The osteotomy, placed just proximal to the calcaneocuboid joint, is lengthened with a graft to restore the medial longitudinal arch and correct peritalar subluxation. While effective, Evans osteotomy may alter joint pressures, particularly at the calcaneocuboid joint. Graft size and shape can influence the degree of correction and load distribution.
A cadaveric flatfoot deformity will be created by partial transection of the spring and talocalcaneal ligaments with release of the talonavicular joint. A 10 mm calcaneal osteotomy will then be performed proximal to the calcaneocuboid joint. Rectangular and triangular 3D-printed grafts, designed in Autodesk Tinkercad and printed with Ideamaker, will be inserted for lengthening. Tekscan sensors will measure contact pressures in the subtalar and talonavicular joints.
Rectangular grafts provide stronger correction but increase lateral overload, while triangular grafts yield more balanced pressure with less correction. Our cadaveric findings support these trends and highlight previously undiscussed changes in medial column pressures. Our purpose is to determine how these changes indicate or contraindicate the use of further surgical and osseous procedures on the medial column.
