FLEXOR TENDON TEARS IN THE HAND - USE OF MR-IMAGING TO DIAGNOSE DEGREE OF INJURY IN A CADAVER MODEL

OBJECTIVE. Treatment of flexor tendon lacerations of the finger partly depends on the degree of injury, which is difficult to determine clin ically, We used a cadaver model to investigate the potential of MR ima ging in evaluating these injuries. MATERIALS AND METHODS. A scalpel wa s drawn transversely across the volar surface of four cadaver hands, p roducing various flexor tendon injuries, MR imaging of each hand was p erformed using axial two-dimensional spin-echo and three-dimensional g radient-recalled-echo sequences. The three-dimensional data sets were interactively reformatted along the long axis of each tendon. The hand s were then dissected; injury to each digit was categorized, measured, and compared with the prospective MR interpretations. RESULTS. Twelve high-grade flexor tendon tears (10 complete tears, with 1- to 14-mm s eparation of the torn ends, and two partial tears involving 50% or mor e of the total tendon cross-sectional area) and two partial tears of l ess than 50% of tendon area were produced; four tendons were not injur ed, Using MR imaging, we diagnosed 11 of the 12 high-grade lesions (th ose involving at least 50% of the total tendon cross-sectional area); the MR images did not show one complete tear whose separation measured 2 mm long at dissection, Ail intact tendons were correctly identified . We underestimated the extent of five lesions but overestimated none. Using the reformatted images, we reduced the number of errors that we would have made interpreting the transverse images alone. CONCLUSION. In this cadaver model, using MR imaging we accurately distinguished d ifferent degrees of flexor tendon tears. The potential of this techniq ue for noninvasively diagnosing flexor tendon injury in patients await s clinical studies.