An anatomical study of flexor pollicis longus blood supply in the distal radius and locking screw locations of volar locking plates: a cadaver study

Abstract

Flexor pollicis longus (FPL) tendon injuries after volar locking plate (VLP) surgery have been reported in patients with distal radius fractures (DRFs). Irritation due to plate prominence or tendon degradation due to deteriorating blood flow is an important factor in FPL tendon ruptures. The purpose of this study was to identify the vessels feeding the FPL and to investigate the articular support of various volar locking plates attached as distally as possible in cadaver wrists. The study involved the dissection of 14 upper limb specimens (8 men and 6 women). The dissections identified the FPL and its related feeding arteries, which were the radial artery (RA) and anterior interosseous artery (AIA). We measured the length of each. Thereafter, we attached each plate in six different cadavers. We attempted to position each plate as distally as possible without FPL tendon contact. We obtained lateral radiographs and analyzed the drill locations. The distances between the drill and the articular surface were over 3 mm in most measurements for the 4 fixed locking plates and that for the 2 variable-angle locking plates were more than 4.9 mm. All plates showed low subchondral support when attempting to avoid FPL tendon contact. The most distal branch of the RA is frequently injured during VLP surgery because of its proximity to the surgical field. Careful preservation of the most distal branch of the AIA is recommended for preventing deterioration of blood flow to the FPL and development of hematomas.