Friday, March 12, 2004
Because the radial artery has a highly variable course around the scaphoid bone, researchers for Poster Exhibit P452 sought to define safe surgical parameters for three different approaches.
Researchers dissected 11 embalmed wrists and exposed the scaphoid using three different approaches: snuffbox, palmar, and dorsal. In each case, the radial artery was localized to specific anatomic landmarks.
With the snuffbox approach, researchers found no absolute safe zone due to the anatomic variability of the course of the radial artery. However, they were able to identify a relative safe zone, located just distal to and equidistant from the radial styloid in the dorsal and palmar planes. They defined this point as the Optimal Entry Point (OEP). They found the OEP to be both a relatively safe entry point with regard to adjacent structures and an optimal entry point for intercarpal fixation in the scaphoid.
With the Palmar approach, researchers found that the superficial branch of the radial artery has a variable course around the scaphoid tubercle. The course may be to either the ulnar or radial side of the scaphoid and as close as 5 mm from its center. Based on this information, researchers recommend that this approach requires a limited incision and blunt spreading for closed fixation of scaphoid fractures.
The close association between the radial artery and the scaphoid waist (a mean distance of 1.7 mm) means that a surgeon using the dorsal approach may not be able to visualize the extracapsular radial artery from within the capsule. An awareness of its proximity to the scaphoid waist, however, should reduce the risk of iatrogenic injury.
Researchers included Steve K. Lee, MD; Alexis Chiang, MD; Ericka Ann Lawler, MD; Steven Marshall Green, MD, and Martin A Posner, MD, all of New York City and Sacha D. Matthews, MD, of Portland, Maine
|Using the palmar approach|
|The snuffbox approach: no absolute safe zone, bu an OEP (Optimal Entry Point)|
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Last modified 20/February/2004