Contributor: Nick Hatch, MD
- An AC (acromioclavicular joint) separation in the shoulder is a common traumatic injury
- XRs can help rule out other injuries as well as help with grading the injury
- There are six different grades for AC separations:
- Grade I: is stretching of the AC ligament without disruption or displacement of the clavicle and recovers with time.
- Grade II: is partial tearing of the AC ligament with some displacement but will also heal with time.
- Grade III: is a full separation with ligament rupture and may require surgery but is not always indicated. Surgery is more common in active patients.
- Grades IV, V, and VI are severe separations and all require surgery.
- Other ligament damage or tears, like a slap injury, can mimic an AC separation and often require surgery but should remain on the differential diagnosis when working up shoulder trauma.
- Setting expectations is key. Patients with a grade 1 or 2 separation should expect 6+ weeks of limited range of motion and up to 12 weeks until return to full function.
- Cosmetically there may be a persistent bump on the shoulder.
van Bergen CJA, van Bemmel AF, Alta TDW, van Noort A. New insights in the treatment of acromioclavicular separation. World J Orthop. 2017;8(12):861‐873. Published 2017 Dec 18. doi:10.5312/wjo.v8.i12.861
Summarized by Jackson Roos, MS4 | Edited by Erik Verzemnieks, MD