Distal intersection syndrome


The ECRB, ECRL and EPL tendons intersect distal to Lister’s tubercle and the radiocarpal joint. The tubercle acts as a pulley, changing the EPL tendon angle as it crosses superficially over the ECRL and ECRB tendons. This creates a mechanically disadvantageous arrangement, where the motion of the thumb and hand may cause friction between these tendons.