Asymptomatic Flexor Tendon Damages after Volar Locking Plate Fixation of Distal Radius Fractures.

Abstract

To investigate asymptomatic flexor tendon damages after volar locking plate fixation of distal radius fractures in 32 wrists of 32 patients with distal radius fractures fixed using two plate types. Sixteen patients received the Acu-Loc volar distal radius plate, and the remaining 16 patients received the Aptus distal radius correction plate. The flexor pollicis longus (FPL) tendon and flexor digitorum profundus were evaluated according to intraoperative findings at plate removal. Ultrasonography was used to measure the distance between the FPL tendon and distal edge of the plates (FPL plate distance) before plate removal, the distance between the FPL tendon and distal edge of the radius (FPL radius distance) after plate removal, in the contralateral wrist, and the angle between an extension line of a volar surface line on the proximal FPL tendon and a second volar surface line on the distal FPL tendon (FPL angles). Erosion of the FPL tendon was identified in four wrists, and erosion of the flexor digitorum profundus of the index finger was identified in one wrist. All five cases of wrists with flexor tendon damage had Acu-Loc plates installed. The average FPL angle before plate removal was 15.4° in the wrists with tendon damage, which was statistically significantly larger than the average FPL angle in the wrists without erosion. The type of plate and larger FPL angle on ultrasonography may be the risk factors for flexor tendon damage.