This is a cadaveric study describes the use of a radial portal to improve visualization of the carpometacarpal joint of the thumb. The authors made use of six fresh frozen adult cadaveric hands. The ulnar portal was marked just ulnar to the extensor pollicis brevis tendon at the level of the joint. The new radial portal was marked just distal to the apical ridge of the trapezium. The carpometacarpal joint was dissected. The distances from the superficial radial nerve and radial artery were measured. The authors stated they had improved visualization of the palmar oblique ligaments and a complete view of the lateral side of the joint. The radial artery was in proximity to the radial portal in two specimens in the distance of 10 and 15 mm from the portal.
This study documents the difficulty in using instrumentation with portal placement in the carpometacarpal joint of the thumb. The findings demonstrate that more radial placement of the radial portal may be performed to provide better visualization and also to separate the hand for better instrumentation. It is concerning that the authors only used six fresh frozen hands to document the safety of these portals. While they conclude that it is safe, and that radiopalmar variations of the radial artery were noted only two of their six hands, this still represents 30% of hands used in this study. It is therefore significant that in one-third of cases, the radial artery will be within 10 to 15 mm of this new portal.