Image-based navigation improves the positioning of the humeral component in total elbow arthroplasty

Stem abutment affects alignment of the humeral component in computer-assisted elbow arthroplasty

“…25 Computerassisted alignment was performed using a magnetic tracking system (Flock of Birds, Ascension Technologies Inc, Milton, VT), with receivers secured to the humerus and the implant to facilitate intraoperative guidance. Computer-assisted alignment involved (1) preoperative planning, (2) registration, and (3) navigation.…”

“…3). 25 A digitizing probe was used to digitize humeral surface landmarks relative to the intraoperative environment. Nonarticular landmarks were selected that could be accurately registered to within 1.0 mm and 0.5 .…”

“…25 This recent study used a modified humeral implant component since the accuracy of the computer-assisted technique was to be validated independently of variations in distal humeral morphology. Clinically, however, morphologic variations must be considered when using computer-assisted techniques.…”

Determination of Elbow Flexion-Extension Axis Based on Planar and Closed B-Splines

“…One of the main factors contributing to the successful long term outcome of the surgical arthroplastic procedure is related to the accurate replication of the primary rotational axis of the elbow [13], commonly termed flexion-extension (FE) axis. Indeed, the misalignment between native and artificial FE axes alters elbow kinematics and eventually leads to implant failures, whose avoidance is highly desirable from both patient and health care economics perspectives [20].…”

“…One of the first ideas in this regard was to digitize the anatomy of the capitellum and trochlea by means of a contact-based stylus, followed by the use of least-square fitting method to determine the corresponding geometric centers [16,10]. However, since this approach is only possible in context of in vitro studies, its later enhancements relied on CT-acquired data [9,19,20]. One of the major advantages of the "offline" imaging-based methods is that after the incipient in vitro development and validation, they can be subsequenly extended to patients by means of conventional fiducial-based registration procedures [19].…”