Comparative accuracy of radiostereometric and optical tracking systems

Non-invasive determination of coupled motion of the scapula and humerus—An in-vitro validation

“…This study presents the translation and rotation differences between a non-invasive markerless DFIS model-based tracking technique for measuring shoulder biomechanics with respect to a widely accepted RSA (de Bruin et al, 2008;Kedgley et al, 2009;Vrooman et al, 1998;Valstar et al, 2000) marker-based technique during simulated dynamic shoulder motion. The results show that this dynamic model-based tracking technique was close to the RSA within approximately 70.3 mm in translation and 70.51 in rotation.…”

“…A radiostereometric analysis (RSA) (de Bruin et al, 2008;Kedgley et al, 2009;Vrooman et al, 1998;Valstar et al, 2000) marker-based tracking technique was used as a reference for measuring shoulder kinematics during simulated shoulder motion of a cadaver specimen. Previously our laboratory has validated this technique in the knee , spine (Wang et al, 2008) and ankle (Wan et al, 2006); and based upon these results, we hypothesized that the technique would track the scapula and humerus similarly to the RSA.…”

The effect of decreasing computed tomography dosage on radiostereometric analysis (RSA) accuracy at the glenohumeral joint

“…The standard RSA method used in this study was validated, reporting accuracies of 0.032 mm and 0.1211 (Kedgley et al, 2009a). In reducing CT dosage, there are two factors that would compromise standard RSA accuracy: the abilities to accurately locate the embedded beads and digitize the bony landmarks.…”

“…Using the ''gold standards'' of the cross-slide table and standard RSA (Kedgley et al, 2009a), the markerless RSA method measured glenohumeral kinematics with an accuracy of 0.096 mm and 1.351. Average inter-operator reliabilities were found to be 0.49 mm and 0.751 and average intra-operator reliabilities were found to be 0.58 mm and 0.531 (Allen, 2009).…”

An alternative definition of the scapular coordinate system for use with RSA

“…In each orientation, a fluoroscopic RSA system (Kedgley et al, 2009) consisting of two fluoroscopy units (SIREMOBIL Compact (L), Siemens Medical Solutions USA Inc., Malvern, PA, USA) was used to determine the locations of the beads within the scapula and humerus. Locations of the beads relative to landmarks of interest on the models were determined by thresholding and sphere-fitting operations within MIMICS.…”