Reducing the risk of flexor pollicis longus tendon rupture after volar plate fixation for distal radius fractures: validation of the tendon irritation test.

Abstract

We have proposed that a positive tendon irritation test is suggestive of flexor pollicis longus (FPL) tendon damage that can lead to tendon rupture after volar plate fixation for distal radius fractures. We investigated cases of postsurgical hardware removal and validated the tendon irritation test as a way to elicit a sign of FPL tendon irritation. We performed hardware removal from 30 wrists in 28 consecutive patients after volar plate fixation. Subjects included 9 men and 19 women with an average age of 58.8 years. The duration of internal fixation averaged 14.5 months. We investigated the efficacy of the tendon irritation test to elicit a sign of tendon irritation before hardware removal, and we intraoperatively evaluated the presence of FPL tendon injuries. Twenty-four of 30 wrists exhibited a sign of tendon irritation. There was no statistical correlation between a sign of tendon irritation and patient age or the duration of internal fixation. We diagnosed 10 wrists with tenosynovitis and 8 frayed tendons. The sensitivity of the tendon irritation test to identify a sign of tendon irritation that was associated with FPL tendon injuries was 80.0%, and its specificity to correctly identify non-injured FPL tendons was 40.0%. The duration of internal fixation associated with tendon fraying was significantly longer than it was in cases of non-injured tendons and tenosynovitis. Our results suggest that subsequent examinations should be performed when the tendon irritation test is positive for signs of tendon irritation that may require plate removal.