This 34-year-old woman presents after a motor vehicle accident. She has right shoulder pain radiating down her arm with numbness and tingling in her fingers.
- Take a look at image 1, an axial proton-density fat-suppressed water-weighted sequence. What do you notice about the posterior labrum highlighted by the orange arrow?
- What do you think of the pink arrows and what might they represent in this patient with an obvious posterior dislocation?
- On image 2, to what sign is the green arrow pointing?
- What about the yellow arrow?
- Putting it all together, given the history of tingling and numbness in the fingers, what should you do next clinically and radiographically?
- The orange arrow indicates the posterior labrum is normal.
- The pink arrows point to a ruptured capsule and separated periosteum.
- The green arrow shows a reversed Hill-Sachs fracture.
- The yellow arrow indicates the quadrilateral space. Its boundary is formed by the long head of the triceps and the humerus medially and laterally and the teres minor and major superiorly and inferiorly. Within it courses the axillary nerve branches along with a posterior circumflex humeral artery. While there is swelling in this region making the structures ill-defined, this would not explain the patient’s tingling and numbness in the fingers.
- Clinically, you should try to establish which nerves are involved by examining the patient’s reflexes and specific dermatome. Radiographically, a search of the brachial plexus from the axilla back to the cervical spine to search for a traction injury of such would be of critical importance.
For more case review, head to MRI Online.