APL Distal Insertion Variability: Cadaveric Variation in Abductor Pollicis Longus Accessory Slip Insertion Site

Abstract

Fifteen cadaveric specimens where dissected to identify the insertion site(s) of Abductor Pollicis Longus tendon and accessory slips.  Thirteen dissections revealed accessory slips with variable insertion sites leaving only two specimens with a single APL insertion.  Eight dissections revealed three APL slips, three with three APL slips and two with four slips.  APL slip insertion sites included: 20 slips inserting of the first metacarpal base, 13 slips inserting on the Trapezium and 2 on the Oppenens Pollicis.  Variation was noted in both presents and number of accessory slips of the APL as well as accessory slip insertion sites.