Hyperextension injuries to the finger joints

Abstract

FIG. I. Dissection specimen showing intact interphaIangea1 Iigaments (I) and the bony protuberances at the insertion of the extensor tendon at (2) the distaI phaIanx and (3) the proximal phalanx; note that the interphaIangea1 ligaments are sturdy structures. FIG. 2. Dissection specimen of finger showing hyperextension at distal joint; note that point of insertion of extensor tendon (I) is pressed against dorsum of middle phaIanx by action of interphaIangea1 ligaments. Bony protuberance at site of insertion of the middle slip of the extensor tendon has been pinched off already by hyperextension at the proxima1 joint (2); note sturdy interphalangeaf ligaments (3).