The motion between components in a mobile-bearing total ankle replacement measured by cone-beam CT scanning

Abstract

BackgroundTo measure the motion of polyethylene insert and implant components of mobile-bearing total ankle replacement (TAR) by cone-beam CT scanning. Methods10 TAR patients with high amount of clinical motion after the CCI implant (Ceramic Coated Implant; Wright Medical Technology, Arlington, TN, USA) with average age at operation 64,3 years (range 47–84) and average clinical total range of motion 42 degrees (range 35–55) were included. ResultsThe average total range of motion between the insert and the tibial component was 0.8mm (range 0–2) in the coronal plane, and 2.9mm (range 1–6) in the sagittal plane. There was wide variation in the axial rotation measurements between the components. ConclusionWe found measurable motion between the mobile-bearing insert and the tibial component in all planes. The relevance of this motion to the function and long-term survival of the TAR remains to be determined.