The influence of the axial, antero-posterior and lateral positions of the center of rotation of a ball-and-socket disc prosthesis on the cervical spine biomechanics

Fabio Galbusera, Federica Anasetti, Chiara Maria Bellini, Francesco Costa, Maurizio Fornari

Research output: Contribution to journalArticlepeer-review

Abstract

Background: Previous studies documented the importance of the positioning and the design parameters of the prosthesis in determining the biomechanics of the implanted spine. However, a comprehensive biomechanical evaluation of the significance of these parameters is still lacking. Therefore, the paper is aimed to the quantification of their influence on the flexibility of the implanted spine and the force transmitted through the facet joints. Methods: A finite element model of the C5-C6 spine unit including a ball-and-socket disc prosthesis was built. Three probabilistic variables were considered: the axial, antero-posterior and lateral positions of the center of rotation. Randomized input parameters were generated with the Monte Carlo method. Pure moments of 1.6 Nm in flexion, extension, lateral bending and axial rotation were imposed to the upper endplate of C5; 100 simulations were conducted for the each of the considered loading conditions. Findings: Axial position of the center of rotation influenced the spine flexibility in all loading conditions and the facet force in extension, lateral bending and axial rotation. The antero-posterior position was found to influence the spine flexibility in flexion and extension, and the facet force in lateral bending and axial rotation. The lateral position was not significant. Interpretation: The effects of the positioning of a cervical disc prosthesis were estimated. A wide range of mechanical behaviors can be obtained by the manufacturers by appropriately manipulating the position of the center of rotation. A proper positioning of the artificial disc during the surgery, in particular in the antero-posterior direction, was found to be of critical importance.

Original languageEnglish
Pages (from-to)397-401
Number of pages5
JournalClinical Biomechanics
Volume25
Issue number5
DOIs
Publication statusPublished - Jun 2010

Keywords

  • Cervical biomechanics
  • Cervical disc replacement
  • Finite element
  • Probabilistic model
  • Total disc arthroplasty

ASJC Scopus subject areas

  • Biophysics
  • Orthopedics and Sports Medicine

Fingerprint Dive into the research topics of 'The influence of the axial, antero-posterior and lateral positions of the center of rotation of a ball-and-socket disc prosthesis on the cervical spine biomechanics'. Together they form a unique fingerprint.

Cite this