Injuries to the distal gastrocnemius muscle: MR findings

Purpose: The purpose of this work was to demonstrate the MR findings of inj uries to the distal gastrocnemius muscle. Method: Twenty patients with clinically confirmed injuries to the distal ga strocnemius muscle underwent MRI. The injuries were evaluated with regard t o abnormal morphology or signal abnormality, site. and degree of tearing. Results: Twenty-three injuries to the distal gastrocnemius occurred in 20 p atients, with involvement of the myotendinous junction in 22 of 23 (96%) in juries. An interstitial tear of the proximal Achilles tendon was present in one instance. Myotendinous strains were the most common injuries (10/23; 4 3%); partial tears (7/23; 30%) and complete tears (5/23; 22%) of the myoten dinous junction or proximal Achilles tendon were less frequent. When an inj ury to the gastrocnemius myotendinous junction was present. involvement of the medial head (19/22; 86%) was more frequent than involvement of the late ral head (3/22; 14%). Conclusion: MRI allows accurate imaging of distal gastrocnemius muscle inju ries. When occurring, distal gastrocnemius muscle injuries most frequently involve the myotendinous junction of the medial gastrocnemius head and occa sionally the lateral gastrocnemius head or the proximal Achilles tendon.