THE NONARTICULATING PORTION OF THE RADIAL HEAD - ANATOMIC AND CLINICAL CORRELATIONS FOR INTERNAL-FIXATION

The proximal radioulnar joint was dissected in 24 cadaveric elbows to localize the area of the radial head that did not articulate with the lesser sigmoid notch of the ulna. The nonarticulating portion of the r adial head was posterolateral in the anatomic position of full supinat ion. Gross observations of the nonarticulating portion of the radial h ead revealed a thinner band of yellowish cartilage relative to a wider , white, glistening cartilage of the articular portion of the radial h ead. The nonarticular portion of the radial head did not contain the a ngled peak, which is most prominent in the middle of the articular por tion. The average are of the nonarticulating radial head was 113 degre es (range, 106 degrees to 120 degrees; standard deviation, 4 degrees). This nonarticulating portion of the radial head (or safe zone for pro minent fixation) consistently encompassed a 90 degrees angle localized by palpation of the radial styloid and Lister's tubercle. Using these palpable distal landmarks to localize the safe zone of the radial hea d, 24 different cadaveric elbows were internally fixed with a plate an d screws through 3 different approaches (anterior, lateral, and poster olateral). Regardless of approach, the internal fixation allowed full forearm rotation in all the specimens. Utilization of this method and anatomic landmarks to localize the nonarticular portion of the radial head may assist the surgeon in open reduction and internal fixation of fractures of the radial head and neck. (J Hand Surg 1998;23A:1082-109 0. Copyright (C) 1998 by the American Society for Surgery of the Hand. ).