Closed ruptures of the flexor digitorum tendons: MRI evaluation

To assess the MRI findings in cases of closed rupture of the flexor digitorum tendons (FDT).

Ten patients with a clinical suspicion of rupture of FDT underwent MRI before surgery. None of the patients presented a skin injury. Fingers were imaged using axial T1-weighted SE sequences, three-dimensional GE images, and curved reconstructions.

Twelve FDT had surgical confirmation of rupture. Flexor digitorum profundus (FDP) and flexor pollicis longus (FPL) tendons were more frequently ruptured (n=8) than flexor digitorum superficialis (FDS) tendons (n=4). MR images accurately depicted the level of the rupture. The gap between the tendon ends (mean 45 mm, range 21-70 mm) was assessed best with curved reconstructions and was well correlated with the surgical findings. The proximal end mainly retracted into the palm or the carpal tunnel (n=8), and less frequently into the digital canal (n=4). In two cases, the proximal end curled up in the palm, clinically simulating a rupture of a lumbrical muscle in one case. MRI also showed the appearance of the adjacent tendons.

MRI accurately depicted the level of rupture and the gap between the tendon ends, which assisted the surgical choice between suture, graft or tendon transfer.