29-year-old female with self-reported dislocation one month prior that was self reduced. LIGAMENTS: The majority of the lateral collateral ligament proper is poorly defined, the radiocapitellar articulation is slightly widened, and the long axis of the radius is directed posterior to the center of the capitellum on the sagittal images. These findings suggest a tear of the lateral collateral ligament, although there may be a few fibers intact anteriorly. Although the distal fibers of the lateral ulnar collateral ligament can be seen inserting on the ulna, the proximal fibers are not well visualized likely representing a tear.The proximal fibers of the anterior bundle of the ulnar collateral ligament are not well-visualized indicating rupture. We suspect that the tear involves the posterior bundle as well.TENDONS: The tendon of the extensor carpi radialis brevis can be traced to its origin at the lateral epicondyle. However, the more posterior components of the common extensor tendon, including the extensor digitorum and extensor carpi ulnaris, show increased signal intensity proximally and do not clearly extend to the lateral epicondyle, indicating at least an incomplete tear of the common extensor tendon. The anconeus muscle may also be at least partially stripped from its humeral origin. There is mild edema within the proximal fibers of the extensor digitorum as well as the proximal fibers of the extensor carpi radialis longus, with slight heterogeneity of signal of the soft tissues lateral to the lateral epicondyle, likely corresponding to small foci of ossification seen on recent radiographs.There is mild edema of the brachialis muscle, but the brachialis tendon can be followed to its insertion on the ulna. The biceps muscle and tendon appear normal.There is edema within the pronator muscle and proximal fibers of the flexor digitorum superficialis indicating a strain injury. The edema extends into the fibers of the common extensor tendon, but I see no full-thickness tear.The triceps tendon is intact.ARTICULAR SURFACES AND BONE: There is edema within the capitellum (extending into the lateral epicondyle) and head and neck of the radius which may represent bone contusion, but we see no discrete fracture line. The articular cartilage of the radial head is difficult to discern on this study which may represent traumatic tearing, although this is equivocal. There is also edema within the medial epicondyle, without discrete fracture.SURROUNDING STRUCTURES: The ulnar nerve appears perched upon the posteromedial aspect of the medial humeral condyle suggesting subluxation.ADDITIONAL
1. Disruption of the lateral collateral ligament, lateral ulnar collateral ligament, and at least incomplete tearing of the common extensor tendon.2. Disruption of the ulnar collateral ligament and strain of the proximal flexor/pronator musculature.3. Subluxation of the ulnar nerve.3. Small joint effusion. Other findings as described above. 