Mo Salah Mo Problems - The ACJ

A 26 year old footballer was thrown to the ground during a football match in Kiev.  After trying to play on he has to be substituted with a shoulder injury.  One day later he is diagnosed with an acromioclavicular joint sprain. 

Anatomy of the ACJ:

From Gray's anatomy 

The acromioclavicular joint (ACJ) unites the distal clavicle and the acromion of the scapula. It contains an intra-articular disc, a synovial membrane, and articular cartilage that cover the distal end of the clavicle and the opposing surface of the acromion. (1) By the age of 40, most patients have narrowing of the joint space and possibly other degenerative findings. (2)


Direct palpation that elicits focal tenderness at the joint is a sensitive but nonspecific finding. (3)

No specific test has proven diagnostic accuracy. (4)

But if there is no pain on direct palpation of the ACJ injury is unlikely.  

Palpation of the ACJ. Courtesy of Scott Koehler, MD.

Here is the Geeky Medic video on Shoulder examination:

(Don't forget our podcast on shoulder examination)

Injuries to the ACJ:

Injuries to the ACJ are graded with the Rockwood Classification I-VI depending on how much disruption there is the ACJ

Rockwood I means minimal disruption and so sprain would be diagnosed.  This can be managed conservatively with a sling

For more information on the Rockwood classification visit Orthobullets

Radiopaedia have an excellent article on the ACJ; here are their examples of a normal ACJ on radiograph.  

Learning Points:

  1. There is no definite test for ACJ injury and a full history and examination must be performed but if there is no tenderness on direct palpation of the ACJ then injury there is unlikely
  2. ACJ injury is graded with the Rockwood Classification I-VI
  3. ACJ sprain would show minimal disruption on radiograph and be managed with a sling


(1) Renfree KJ, Wright TW; Anatomy and biomechanics of the acromioclavicular and sternoclavicular joints. Clin Sports Med. 2003;22(2):219.

(2) Montellese P, Dancy T; The acromioclavicular joint; Prim Care. 2004;31(4):857.

(3) Walton J, Mahajan S, Paxinos A, Marshall J, Bryant C, Shnier R, Quinn R, Murrell GA; Diagnostic values of tests for acromioclavicular joint pain; J Bone Joint Surg Am. 2004;86-A(4):807. 

(4) Hegedus EJ, Goode A, Campbell S, Morin A, Tamaddoni M, Moorman CT 3rd, Cook C Physical examination tests of the shoulder: a systematic review with meta-analysis of individual tests; Br J Sports Med. 2008;42(2):80.