Biomechanical Evaluation With a Novel Cadaveric Model Using Supination and Pronation Testing of a Lisfranc Ligament Injury

Abstract

Background: Lisfranc joint injuries can be due to direct or indirect trauma and while the precise mechanisms are unknown, twisting or axial force through the foot is a suspected contributor. Cadaveric models are a useful way to evaluate injury patterns and models of fixation, but a frequent limitation is the amount of joint displacement after injury. The purpose of this study was to test a cadaveric model that includes axial load, foot plantarflexion and pronation-supination motion, which could re-create bone diastasis similar to what is seen in subtle Lisfranc injuries. Our hypothesis was that applying pronation and supination motion to a cadaveric model would produce reliable and measurable bone displacements. Methods: Twenty-four fresh-frozen lower leg cadaveric specimens were used. The medial (C1) and intermediate (C2) cuneiforms and the first (M1) and second (M2) metatarsal bones were marked. A complete ligament injury was performed between C1-C2 and C1-M2 in 12 specimens (group 1), and between C1-C2, C1-M2, C1-M1, and C2-M2 in 12 matched specimens (group 2). Foot pronation and supination in addition to an axial load of 400 N was applied to the specimens. A 3D digitizer was used to measure bone distances. Results: After ligament injury, distances changed as follows: C1-C2 increased 3 mm (23%) with supination; C1-M2 increased 4 mm (21%) with pronation (no differences between groups). As expected, distances between C1-M1 and C2-M2 only changed in group 2, increasing 3 mm (14%) and 2 mm (16%), respectively (no differences between pronation and supination). M1-M2 and C2-M1 distances did not reach significant difference for any condition. Conclusions: Pronation or supination in addition to axial load produced measurable bone displacements in a cadaveric model of Lisfranc injury using sectioned ligaments. Distances M1-M2 and C2-M1 were not reliable to detect injury in this model. Clinical Relevance: This new cadaveric Lisfranc model included foot pronation-supination in addition to axial load delivering measurable bone diastasis. It was a reliable Lisfranc cadaveric model that could be used to test different Lisfranc reconstructions.

Biomechanical Cadaveric Evaluation of the Role of Medial Column Instability in Hallux Valgus Deformity

“…We did not expect big angular changes in our results, as it has been seen in other midfoot cadaveric studies that when ligament damage is introduced, only millimetric changes are observed. 18 In summary, our study shows that in a novel cadaveric model where axial load and pronation of the foot are applied, progressive damage of the medial column translates into significant pronation on the first ray. The naviculocuneiform joint ligament damage is the most significant one responsible for instability of the first ray, considering pronation and valgus deviation.…”

“…It is highly interesting that intercuneiform damage did not produce any significant change in alignment of the analyzed segments, as one could predict from Lisfranc damage literature that C1C2 and C1M2 damage were the most important midfoot ligaments connecting the forefoot to the midfoot. 18 Having said this, we were not interested in generating a midfoot collapse, and it can be possible that a complete plantar damage to the C1C2 and C1M2 ligaments with higher axial load could have shown alignment changes. To be noted too is the small effect damage over C1M1 generated on segment alignment, as it produced small supinating changes in the frontal plane and small variable changes in the axial plane.…”

“…A dead weight equal to 50% of the stance phase force was applied to the FHL to add a valgus moment to the hallux 9 as it has been shown that is one of the factors contributing to the deformity. 14 We used a similar setup as the one described by Wagner et al 18 The specimen was mounted onto a specific frame designed for this experiment, allowing the specimen to remain vertical. On top of the jig, a special disc to support weight was incorporated, along with a set of bearings to allow a smooth axial rotation of the rod.…”

“…11 A published model that used this concept was published in 2020, in a Lisfranc fracture model, where the authors included foot pronation-supination in addition to axial load delivering measurable bone diastasis in the midfoot area. 18 Our objective was to design a cadaveric foot model where we could re-create through progressive medial column ligament damage some of the components of a hallux valgus deformity. We hypothesized that in this model we would be able to obtain a progressive varus inclination and pronation of the first metatarsal along with the progressive damage introduced.…”

Comparison of Suture-Augmented Ligamentplasty to Transarticular Screws in a Lisfranc Cadaveric Model

“…The specimens were fixed to the E10000 Instron ElectroPuls Materials Testing Machine (Instron, Norwood, MA). The specimen mounting specifications and testing methods are well described in a sister study (Wagner et al’s Lisfranc model study 17 ). Relative positions of the screw heads were analyzed using SolidWorks 2017 (Dassault Systems, SolidWorks Corp, Waltham, MA).…”