Background: Flexor tendon injuries are common injuries typically seen in the working-age (20 to 45 years) young male population1. These injuries can be debilitating and lead to significant morbidity, as most flexor tendon lacerations require surgical treatment for proper healing. There is increasing use of both preoperative and postoperative ultrasound to aid in evaluation of flexor tendon injuries.
Purpose: The purpose of this study was to determine if ultrasound was a modality that could be useful intraoperatively in the localization of Zone II retracted flexor tendon injuries, as well as to determine how accurate ultrasound is in measuring the defect. Time to localization and measurement were also investigated.
Methods: Zone II flexor tendon injuries, distal to the A1 pulley were created in 2 cadaveric hands for a total of 18 tendon lacerations, which were retracted at varying degrees into the palm in a random fashion by an assistant hand fellow. An ultrasound machine was used by the investigating hand fellow first, to locate the proximal end of the injured tendon and second, to measure the amount of retraction. The 2 cadaveric hands underwent careful dissection to quantify the actual retraction distance for each lacerated flexor tendon. The measurements for all tendons from both hands were compared using a paired-t-test. The time it took to identify and measure the injury was also recorded.
Results: The proximal end of each lacerated tendon was successfully identified in 100% of cases (10/10 tendons). There was a clinically significant difference (P=0.0002) between the anatomically verified tendon retraction distance and the ultrasound measured retraction distance. Clinically, however, the difference was minimal with an average difference of 2.8 mm, which is well within 5 mm of difference. The average time to localize the retracted tendon was 52.1 seconds. The average time to localize and measure the retracted was 3 minutes and 31 seconds.
Conclusion: Ultrasound is a reliable modality in the localization and measurement of retracted flexor tendon injuries. This may help to prevent unnecessary exploration and limit the incisions made during the localization of retracted flexor tendons intraoperatively.
