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

• Published in: Foot and ankle surgery Vol. 28; no. 3; pp. 324 - 330
• Main Authors: Koivu, Helka, Kormi, Sami, Kohonen, Ia, Tiusanen, Hannu
• Format: Journal Article
• Language: English
• Published: France Elsevier Ltd 01-04-2022
• Subjects: Cone-beam computed tomography; Mobile-bearing; Rotation; Total ankle replacement; Total ankle replacement; Cone-beam computed tomography; Rotation; Mobile-bearing
• ISSN: 1268-7731; 1460-9584
• DOI: 10.1016/j.fas.2021.04.002

•The motion between the mobile-bearing TAR components can be measured by CBCT.•There is measurable motion between polyethylene insert and tibial component in the mobile-bearing TAR.•There was a wide variation in the rotation measurements between the components of the mobile-bearing TAR.
To measure the motion of polyethylene insert and implant components of mobile-bearing total ankle replacement (TAR) by cone-beam CT scanning.
10 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.
The 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.
We 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.