Accuracy assessment of an imaging technique to examine ulnohumeral joint congruency during elbow flexion.

A CT-based imaging technique to investigate ulnohumeral joint congruency of elbows undergoing physiologic flexion is introduced. This technique, which employed landmark registration and a previously developed inter-bone distance algorithm, was validated experimentally. Results obtained with this imaging technique were validated in a single specimen by comparing the resulting joint congruency maps to results obtained with experimental casting in a static position. Additionally, the accuracy of the registration technique was assessed in four specimens using fiducial and target registration error to evaluate the positional and angular accuracy. Preliminary data from an intact cadaveric elbow was shown to demonstrate the utility of this technique. The overall accuracy of the registration was better than 1 mm, and the congruency maps showed excellent correspondence with the casting, validating the use of a CT-based imaging technique to examine the congruency of joints undergoing quasi-static flexion.