Response of Charité total disc replacement under physiologic loads: prosthesis component motion patterns

Charité TDR restored near normal quantity of flexion-extension range of motion under a constant physiologic preload; however, the quality of segmental motion differed from the intact case over the flexion-extension range. Whereas some TDRs showed visual evidence of core translation, the predominant angular motion within the prosthesis occurred between the upper end plate and the polyethylene core. Likely factors affecting the function of the Charité TDR include implant placement and orientation, intraoperative change in lordosis, and magnitude of physiologic compressive preload. Further work is needed to assess the effects of the prosthesis motion patterns identified in the study on the load sharing at the implanted level and polyethylene core wear.