Images: 1) X-Ray, 2-3) Obl Coronal PD FS, 4-5) Obl Sag PD FS | Figure 1

MSKrad7

Radiology

Images: 1) X-Ray, 2-3) Obl Coronal PD FS, 4-5) Obl Sag PD FS. As @deleted-account correctly pointed out, this is a grade 3 acromioclavicular separation injury. There is superior displacement of the distal clavicle at the AC joint and there is widening of the coracoclavicular distance (black arrow). MR images demonstrate complete disruption of the AC capsular ligaments (yellow arrow) and the coracoclavicular ligament (blue arrow) with extensive surrounding edema. The rotator cuff (orange arrow) and the glenoid labrum (white arrow) were normal and intact.

Similar cases

Axial T2W FS MR image through the same ankle shows complete disruption of the anterior talofibular ligament (yellow) and disruption of the majority of the deep and superficial deltoid ligament fibers (green). The intact superior components of the posterior talofibular ligament are also demonstrated (pink). #FridayQuizDay

AP radiograph (image 1) of the elbow show a small avulsion fracture (arrow) of the medial epicondyle. The coronal T1-W (image 2), and coronal T2-W (image 3) images show the avulsion fracture and disruption of the ulnar/medial collateral ligament. The medial/ulnar collateral ligament is most commonly injured in throwing athletes. However, it can also be injured in athletes who bear weight using the upper extremity (such as gymnasts and wrestlers). #MSKMonday

pt fell in shower landing on left elbow/forearm. Ttp over left ac joint. No clavicular laxity. I want to call this ac joint sprain grade 2? Possible tear of coracoclavicular ligament but no overt tear of ac ligaments? I placed her in a sling, NSAIDs , pain meds. Sling for 1-2 wks with active rom bid after a couple days. No lifting for 6 wks. Thoughts?

Image description
Sagittal proton density (image 1) and T2-weighted MRI (image 2) show disruption of the anterior cruciate ligament (arrow). A small knee joint effusion is present.
Teaching point
Anterior cruciate ligament rupture is characterized on MRI by fiber discontinuity, abnormal signal within the ligament, and loss of the normal taut orientation. These injuries most commonly occur through a noncontact mechanism involving pivoting, sudden deceleration, or hyperextension of the knee. Associated findings may include joint effusion, bone contusions of the lateral femoral condyle and posterolateral tibial plateau, and injury to secondary stabilizing structures, which can help support the diagnosis when direct ligament findings are subtle.