The diagnostic value of high resolution ultrasound in the diagnose of dose injury of the extensor digitorum tendons

Objective To explore the clinical value of high resolution ultrasound in the diagnose of digitorm extensor tendon close injury. Methods From April 2005 to October 2008, close injury of the extensor digitorum tendons was diagnosed using high resolution ultrasound in our hospital. The characteristics of ultrasound images of 21 patients whose diagnosis was confirmed by surgery were retrospectively analyzed. Results The extensor digitorum tendons of 10 patients were injured in Zone Ⅰ. Ultrasonic images showed that the low echogenic area was located in the site of extensor tendon insertion into the distal phalanx and the base of the distal phalanx was volarly displaced. The kinesis observation showed that no movement occurred when the patient actively moved the distal interphalangeal joint. There was distal p halanx avulsion fracture and displacement in 3 patients. Zone Ⅱ injury of extensor digitorum tendons was seen in 6 patients. The tendon hood was completely ruptured in 2 cases shown as interruption of continuity of the tendon hood on ultrasonograph. The structure of the tendon hood was disoriented and there was abnormal dark area. The kinesis observation showed that the two ends of tendon hood were separated upon and the tendon slided to the ulnar side of the finger. Tendon hood was injured but not ruptured in 3 cases. Ultrasonographs showed thickening of the tendon, uneven echo signals, and disoriented structures. Iatrogenic tendon hood injury by internal fixation was seen in 1 case. The internal fixation plate could be seen through the tendon and limited tendon excursion. Spontaneous tendon rupture in zone Ⅲ occurred in 5 cases. Ultrasonic images showed uneven echo signals, disoriented tendon fibers, and disrupted tendon integrity. Conclusion High resolution ultrasonic inspection can provide reliable information for the diagnosis of extensor digitorum tendon close injury and valuable clinical information for the choice of operation. Key words: Ultrasonography;  Tendon injuries;  Diagnosis