In vitro-analysis of kinematics and intradiscal pressures in cervical arthroplasty versus fusion – A biomechanical study in a sheep model with two semi-constrained prosthesis

Background As an alternative technique to arthrodesis of the cervical spine, total disc replacement (TDR) has increasingly been used with the aim of restoration of the physiological function of the treated and adjacent motions segments. The purpose of this experimental study was to analyze the kinematics of the target level as well as of the adjacent segments, and to measure the pressures in the proximal and distal disc after arthrodesis as well as after arthroplasty with two different semi-constrained types of prosthesis.