POSTOPERATIVE MR-IMAGING AND ULTRASONOGRAPHY OF SURGICALLY REPAIRED ACHILLES-TENDON RUPTURES

Purpose: To evaluate and compare MR and US findings in an unselected g roup of patients with 1-3-year-old surgically repaired complete ruptur es of the Achilles tendon. Material and Methods: Thirteen patients wit h complete Achilles tendon rupture underwent clinical, MR and US exami nations, The average time interval from rupture to postoperative imagi ng was 18 months. Results. The cross-sectional area of a postoperative tendon was 4.2 times that of the unaffected side. The shape of the op erated tendon was more rounded than the unaffected side and it had irr egular margins both in MR imaging and in US examination. In 4 of 13 ca ses an intratendinous area of intermediate to high signal intensity on proton density- and T2-weighted images was seen on MR; The size of th is area varied from 4 to 18% of the cross-sectional tendon area. Two p atients with the largest intratendinous area had poor clinical outcome . On US the tendon had mixed echogenicity in all cases and the tendon bands were thinner and shorter than normal. Comparison of dimension be tween MR and US revealed that in a.p. dimension the correlation was go od (r=0.87, p=0.001), but in transversal width there was no significan t correlation (r=0.58, p=0.06). Conclusion: The increased size and rou nd irregular area of the operated Achilles tendon rupture was well det ected by both MR and US, but intratendinous lesions were seen only by MR.