Active Weight Bearing Tibio-talar Motion and Meniscal Translation in the S.T.A.R Prosthesis-A Radiographic Comparative Study of the S.T.A.R. Toward the Opposite Normal Ankle JointHakon Kofoed*
The Orthopaedic Clinic, Frederiksberg University Hospital, Capital Region of Denmark
- *Corresponding Author:
- Hakon Kofoed
30 Norasvej, Charlottenlund, Denmark
E-mail: [email protected]
Received Date: December 13, 2012; Accepted Date: December 28, 2012; Published Date: January 02, 2013
Citation: Kofoed H (2013) Active Weight Bearing Tibio-talar Motion and Meniscal Translation in the S.T.A.R Prosthesis-A Radiographic Comparative Study of the S.T.A.R. Toward the Opposite Normal Ankle Joint. Clin Res Foot Ankle 1:101. doi: 10.4172/2329-910X.1000101
Copyright: © 2013 Kofoed H. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Background: The kinematics of meniscal bearing artificial ankle joints is not well documented after the implantation of the prosthesis. Purpose of the study To investigate the active weight-bearing tibio-talar motion and the translation of the meniscus radiographically after mean 36 months in patients with unilateral traumatic ankle osteoarthritis.
Methods: Straight lateral radiographic views under image intensification of the replaced ankle and the opposite normal ankle were performed during active weight-bearing. The tibio-talar motion of both ankles, as well as the translation/rotation of the meniscus in the replaced ankles was measured.
Results: The total range of motion in normal ankles was mean 59° (33.7–68.7). The motion in the replaced ankles was mean 37.2° (16.7–53.3), p<0.02. Normal extension was mean 24° (3.7–37.7). Replaced ankle extension was mean 14.7° (2-26.7), p<0.02. Normal plantarflexion was mean 31° (19.7–51), in replaced ankles plantar flexion was mean 22.3° (12.3–34), p<0.02. The translation of the meniscus was 0.7 mm (-1.5 to 1.2). This could also be calculated to be a rotation of 3.9°. The translation of the meniscus is most probably a combination of gliding and rotation.
Conclusions: The active weight-bearing motion of the replaced ankle is about 2/3 of the normal ankle motion. Functionally this is a satisfactory result. After 36 months the translation of the meniscus is rather small suggestion that the replaced ankle has reached a steady state of conformity.