Loading of fracture fixation plates

The physiological forces that act on bones and devices are crucial to know in the design of fracture fixation plates: if the plates are too rigid, they will shield the bone from load and cause the fracture to heal slowly, and if the plates are too thin, they may break.

With the AnyBody Modeling System, a virtual fracture can be placed on the bone enabling the net forces and moments acting on the fracture to be computed. Alternatively, all the forces acting on the bone (muscle, ligaments, joint contact forces, etc.) can be exported from the AnyBody Modeling System to FE packages such as Abaqus and ANSYS. The detailed dynamic loads in FEA will help you detailing the design of the implant geometry, screw locations, material selection and so on.

Examples

  • Patient-Specific Modelling of Fractures
  • Simulation of fracture fixation devices and fixation techniques
  • Influence of hooks and a lag screw on internal fixation plates
  • Simulation of nail or plate type fixation implants
  • Simulation of load in specific fractures
  • Physiological loads for activities of daily living

Examples of input and output for a fracture fixation model:

Input

  • Implant CAD files (STL)
  • Implant positioning data
  • Motion data and ground reaction force
  • Anthropometrics data

Output

  • Forces and moments in fracture
  • Load files for FE analysis
  • Muscle and ligament forces
  • And much more

Contact us to learn more or to discuss how we could solve your problem

  1. Reproduce the activity, e.g. walking, using your own data or an existing AnyBody model
  2. Create a reference frame in the model on the location of the fracture
  3. Measure the net force and moment acting on the fracture while doing the activity. This is done quickly with a force moment measure object, which essentially works by creating a free body diagram. This measure provides the magnitude of the loads acting on the device.

If strength analysis is required, the loads can be exported to FE packages using the AnyBody interface tools for ANSYS or Abacus.

  • 2017 Sakai R, Uchino M, Yoneo T, Ohtaki Y, Minehara H, Matsuura T, Gomi T, Ujihira M (2017), "Influence of hooks and a lag screw on internal fixation plates for lateral malleolar fracture: a biomechanical and ergonomic study", J. Orthop. Surg. Res., vol. 12, pp. 34. [DOI]
  • 2015 Marie C (2015), "Strength analysis of clavicle fracture fixation devices and fixation techniques using finite element analysis with musculoskeletal force input", Med. Biol. Eng. Comput., vol. 53, pp. 759-769. [DOI]
  • 2016 Camino Willhuber G, Zderic I, Gras F, Wahl D, Sancineto C, Barla J, Windolf M, Richards RG, Gueorguiev B (2016), "Analysis of sacro-iliac joint screw fixation: does quality of reduction and screw orientation influence joint stability? A biomechanical study", Int. Orthop., vol. 40, pp. 1537-1543. [DOI]
  • 2014 Coombs DJ, Wykosky S, Bushelow M (2014), "Calcaneal Fixation Plate Test Method Development", In: SIMULIA Community Conference, May 19-24, 2014, Providence, RI. [PDF]
  • More papers on orthopedics