Ultrasonographic Assessment of the Flexor Pollicis Longus Tendon After Plate Fixation

Rupture of the flexor pollicis longus tendon is a major complication after volar locking plate fixation of distal radius fracture. This study used ultrasonography to assess the flexor pollicis longus tendon and intermediate tissue. The study assessed 27 patients (28 wrists) who underwent removal of the volar locking plate. Before plate removal, radiography and ultrasonography were performed to assess the relation between the flexor pollicis longus tendon and the volar locking plate. Intraoperatively, the authors evaluated the intermediate tissues between the flexor pollicis longus tendon and the distal volar margin of the plate. Preoperative and intraoperative findings were compared. Intraoperative findings were strongly related to the distance between the flexor pollicis longus tendon and the volar locking plate on ultrasonography. The sensitivity of ultrasonography in detecting thin, membrane-like intermediate tissue through which the plate was visible was 95%, and the specificity was 89% if the distance between the flexor pollicis longus tendon and the plate was less than 0.7 mm. Compression of the flexor pollicis longus tendon was seen in 11 cases (39.3%), and this finding suggested the presence of thin, membrane-like intermediate tissue. The study results showed that ultrasonography could be used to identify the type of intermediate tissue between the flexor pollicis longus tendon and the volar locking plate. [Orthopedics. 2017; 40(1):e104-e108.].