Finite Element Method Evaluation: Articulations and Diagonals in an 8‐Pin Type 1B External Skeletal Fixator

Abstract

Supplementing a type 1b ESF with double diagonals and wide double articulations results in the greatest increase in stability at the fracture gap for complex fractures or in the initial phase of bone healing.

A mechanical comparison of veterinary linear external fixation systems

“…2,6,7,9 To limit the number of variables affecting fixator rigidity, the type Ib frames in this study were not supplemented with articulations or diagonals. Clinical experience and a recent finite element study 29 suggest that fixation stability of type Ib constructs can be enhanced by such additions.…”

Biomechanical Analysis of Unilateral External Skeletal Fixators Combined with IM‐Pin and Without IM‐Pin Using Finite‐Element Method

“…Most FEM studies of ESF devices test for axial compression, craniocaudal bending, lateromedial bending, and torsion separately and in combination with widely varying loads applied at the most proximal node. [16][17][18][19] Because the bone column in our study was modeled as a true 3-dimensional model, it was possible to apply a physiologically relevant load at the femoral headrelated node. The load was chosen to approximate body weight and was directed with distal, cranial, and lateral components.…”

“…5,16,17 It has also been used to study the biomechanics of various ESF constructs. 18,19 It has not, however, been used to evaluate an ESF in combination with an IM-pin as it is used in veterinary medicine.…”

What can finite element analysis tell us?

“…Designs of fixation devices (pins, screws, plates) or implants can be optimised using FE models. Lauer et al [5] used FEA to determine the optimal mechanical properties of articulations and diagonals in an external skeletal fixator used in small animals. Computational methods have the advantage that it is more easy to look at greater numbers of variations than is practical in clinical and laboratory testing.…”