ARTHROSCOPIC ANATOMY OF THE LATERAL ELBOW - A COMPARISON OF 3 PORTALS

Ten fresh cadaveric elbows were used to evaluate the proximity of the radial nerve and its branches to three anterolateral portals. A proximal anterolateral portal used routinely at our institution and located 2 cm proximal and 1 cm anterior to the lateral epicondyle was compared with the distal anterolateral portal described by Andrews and with a mid-anterolateral portal. The three portals were initially established without joint distention while the elbows were flexed 90 degrees. Measurements were then obtained with and without joint distention at flexion angles of 0 degrees and 90 degrees. The radial nerve was found to be an average distance of 3.8 mm at extension and 7.2 mm at 90 degrees of flexion from the distal anterolateral portal, located 3 cm distal and I cm anterior to the lateral epicondyle. Conversely, the distance between the proximal anterolateral portal cannula and the nerve was statistically greater (p < 0.05), averaging 7.9 mm in extension and 13.7 mm in flexion. The remaining anterolateral portal, located I cm directly anterior to the lateral epicondyle, was found to be at a statistically greater average distance from the nerve than was the distal anterolateral portal but statistically closer than was the more proximal portal. The ability to visualize the joint arthroscopically was assessed using the three portals, and although the ulnohumeral joint could be adequately seen using ail portals, radiohumeral joint visualization was most complete and technically easiest using the most proximal portal. The proximal anterolateral portal, used in >100 elbow anthroscopies without evidence of radial nerve injury, is recommended for use as the standard lateral access site, allowing excellent visualization while maximizing the distance from the radial nerve throughout the elbow's range of motion.