Hip and knee joint modelling

We have developed biofidelic numerical models of the human pelvis and femur, and have also advanced the understanding of how these structures behave following joint replacement surgery.

We have developed one of the most biofidelic numerical models of the human pelvis, which for the first time included muscular and ligamentous supports [1]. Complex nonlinear models were developed to examine migration of implants after hip replacement (observed clinically) [2]. This work won the best medical engineering PhD award (2005) from the Institution of Mechanical Engineers (IMechE). Ongoing research focuses on implant instability and failures after total [3-5] and partial knee replacements [6-7]. A biomechanical study on unilateral knee replacements received a number of awards including best medical engineering project prize from the IMechE.

 

 

References:

  1. A.T.M. Phillips, P. Pankaj, C.R. Howie, A.S. Usmani, A.H.R.W. Simpson, Finite element modelling of the pelvis: inclusion of muscular and ligamentous boundary conditions. Medical Engineering & Physics, 29 (2007), 739–748. DOI:
    10.1016/j.medengphy.2006.08.010
  2. A.T.M. Phillips, P. Pankaj, C.R. Howie, A.S. Usmani, A.H.R.W. Simpson, 3D non-linear analysis of the acetabular construct following impaction grafting. Computer Methods in Biomechanics and Biomedical Engineering, 9 (2006), 125-133. DOI:10.1080/10255840600732226
  3. N Conlisk, H Gray, P Pankaj, CR Howie, The influence of stem length and fixation on initial femoral component stability in revision total knee replacement. Bone and Joint Research 1 (11), 281-288. DOI:10.1302/2046-3758.111.2000107
  4. N Conlisk, H Gray, P Pankaj, CR Howie, The role of complex clinical scenarios in the failure of modular components following revision total knee arthroplasty: A finite element study. Journal of Orthopaedic Research 33 (8), 1134-1141. DOI:10.1002/jor.22894
  5. N Conlisk, H Gray, P Pankaj, CR Howie, An efficient method to capture the impact of total knee replacement on a variety of simulated patient types: A finite element study. Medical Engineering & Physics 38 (9), 959-968. DOI:http://dx.doi.org/10.1016/j.medengphy.2016.06.014
  6. Scott, CEH, Eaton, MJ, Wade, FA, Nutton, RW, Evans, SL & Pankaj, P 2016, 'Metal backed versus all-polyethylene unicompartmental knee arthroplasty: the effect of implant thickness on proximal tibial strain in an experimentally validated finite element model' Bone & Joint Research.
  7. Scott, CEH, Wade, FA, Bhattacharya, R, MacDonald, D, Pankaj, P & Nutton, RW 2016, 'Changes in Bone Density in Metal-Backed and All-Polyethylene Medial Unicompartmental Knee Arthroplasty' Journal of Arthroplasty, vol 31, no. 3, pp. 702–709., DOI:10.1016/j.arth.2015.09.046
A two panel figure showing biofidelic FE models of the femur and pelvis which include simplified representations of muscles and ligaments.
Fig.1: Finite element models of the femur and pelvis which incorporate muscle and ligament boundary conditions.
A figure showing three different types of unicompartmental knee replacement implants. The first consists of an all polyethylene tibial component, the second a metal-backed tibial component and the thrid a metal-backed mobile bearing component.
Fig.3: Three configurations of a unicompartmental knee replacement (UKR), where the material and constraints vary.
A multi-panel figure showing three different total knee replacement implant configurations (part a), followed by a rendering of an in-vitro test rig apparatus for micromotion measurement (part b), and the actual in-vitro test rig (part c).
Fig.2: Investigation of micromotion following total knee arthroplasty, a) show three different implant configurations, b) a 3D rendering of the test apparatus, and c) the final apparatus in use in the lab..