Fixation of a split fracture of the lateral tibial plateau with a locking screw plate instead of cannulated screws would allow early weight bearing: a computational exploration
- 663 Downloads
To assess, with finite element (FE) calculations, whether immediate weight bearing would be possible after surgical stabilization either with cannulated screws or with a locking plate in a split fracture of the lateral tibial plateau (LTP).
A split fracture of the LTP was recreated in a FE model of a human tibia. A three-dimensional FE model geometry of a human femur-tibia system was obtained from the VAKHUM project database, and was built from CT images from a subject with normal bone morphologies and normal alignment. The mesh of the tibia was reconverted into a geometry of NURBS surfaces. A split fracture of the lateral tibial plateau was reproduced by using geometrical data from patient radiographs. A locking screw plate (LP) and a cannulated screw (CS) systems were modelled to virtually reduce the fracture and 80 kg static body-weight was simulated.
While the simulated body-weight led to clinically acceptable interfragmentary motion, possible traumatic bone shear stresses were predicted nearby the cannulated screws. With a maximum estimation of about 1.7 MPa maximum bone shear stresses, the Polyax system might ensure more reasonable safety margins.
Split fractures of the LTP fixed either with locking screw plate or cannulated screws showed no clinically relevant IFM in a FE model. The locking screw plate showed higher mechanical stability than cannulated screw fixation. The locking screw plate might also allow full or at least partial weight bearing under static posture at time zero.
KeywordsTibial plateau fractures Finite element Weight bearing Interfragmentary motion Bone fixation Fracture fixation
- 3.Tscherne H, Lobenhoffer P (1993) Tibial plateau fractures. Management and expected results. Clin Orthop Relat Res 87–100Google Scholar
- 14.Guo XE (2001) Mechanical properties of cortical bone and cancellous bone tissue. Bone Mech. Handb. Second EdiGoogle Scholar
- 16.ASTM F136 “Standard specification for wrought titanium-6aluminum-4vanadium ELI (extra low interstitial) alloy for surgical implant applications (UNS R56401)Google Scholar
- 21.Haller JM, O’Toole R, Graves M, et al. (2015) How much articular displacement can be detected using fluoroscopy for tibial plateau fractures? InjuryGoogle Scholar
- 22.Claes LE, Heigele CA, Neidlinger-Wilke C, et al. (1998) Effects of mechanical factors on the fracture healing process. Clin Orthop Relat Res S132–S147Google Scholar