Comparison of Two Methods for In Vivo Estimation of the Glenohumeral Joint Rotation Center (GH-JRC) of the Patients with Shoulder Hemiarthroplasty

Comparison of Two Methods for In Vivo Estimation of the Glenohumeral Joint Rotation Center (GH-JRC) of the Patients with Shoulder Hemiarthroplasty

Asadi Nikooyan, A.
Van der Helm, F.C.T.
Westerhoff, P.
Graichen, F.
Bergmann, G.
Veeger, H.E.J.

Mechanical, Maritime and Materials Engineering

Biomechanical Engineering

2011-03-31

Determination of an accurate glenohumeral-joint rotation center (GH-JRC) from marker data is essential for kinematic and dynamic analysis of shoulder motions. Previous studies have focused on the evaluation of the different functional methods for the estimation of the GH-JRC for healthy subjects. The goal of this paper is to compare two widely used functional methods, namely the instantaneous helical axis (IHA) and symmetrical center of rotation (SCoRE) methods, for estimating the GH-JRC in vivo for patients with implanted shoulder hemiarthroplasty. The motion data of five patients were recorded while performing three different dynamic motions (circumduction, abduction, and forward flexion). The GH-JRC was determined using the CT-images of the subjects (geometric GH-JRC) and was also estimated using the two IHA and SCoRE methods. The rotation centers determined using the IHA and SCoRE methods were on average 1.4760.62 cm and 2.0760.55 cm away from geometric GH-JRC, respectively. The two methods differed significantly (two-tailed p-value from paired t-Test ,0.02, post-hoc power ,0.30). The SCoRE method showed a significant lower (two-tailed p-value from paired t-Test ,0.03, post-hoc power ,0.68) repeatability error calculated between the different trials of each motion and each subject and averaged across all measured subjects (0.6260.10 cm for IHA vs. 0.4360.12 cm for SCoRE). It is concluded that the SCoRE appeared to be a more repeatable method whereas the IHA method resulted in a more accurate estimation of the GH-JRC for patients with endoprostheses.

http://resolver.tudelft.nl/uuid:4ce91f4d-0d11-4df1-9582-c0b9d18c35ac

https://doi.org/10.1371/journal.pone.0018488

Public Library of Science

1932-6203

PLos ONE, 6 (3), 2011

Institutional Repository

journal article

(c) 2011 Asadi Nikooyan et al. 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