The Sneaky AC Joint: A Neck Pain Imitator

The Sneaky AC Joint: A Neck Pain Imitator

by Steve Mora MD
Orange County Shoulder Specialist

There is a not so well know shoulder condition which can disguise itself as neck pain.  These problems will present as neck pain but the true culprit causing the pain is actually within the shoulder joint.   Some of these unfortunate patients have undergone risky neck surgery or complex brachial plexus explorations without success.  These patients will continue to have neck and shoulder pain because the problem causing the pain was not addressed.  There is one particular shoulder condition which frequently mimics neck pain.

Anatomy of the AC joint
Pain caused by the Acromioclavicular (AC) joint almost always mimics neck pain.   The AC joint is the “forgotten” joint of the shoulder.  People often think that the shoulder is made up of a single joint.  The shoulder actually has a main joint called the glenohumeral joint and a very small joint called the AC joint.  The AC joint is located on top of the shoulder and is found at the end of the clavicle.  Like many other joints, the AC joint will become arthritic as we get older.  Patients who perform repetitive lifting activities over many years will also develop AC joint arthrosis.  Also patients who suffered an AC joint separation may develop post traumatic arthritis.

Patients with AC joint degeneration will present with pain towards the top of the shoulder and base of the neck.  Sometimes the pain radiates towards the ear or jaw.   On presentation the patient will place their hand on top of the shoulder and point to the side of the neck.

Pain over the top of the shoulder which runs towards the neck is often due to AC joint problems.

Severe tenderness of the AC joint is a diagnostic sign for AC joint disease.
The physical examination will show will show specific tenderness directly over the AC joint and the trapezius muscles which is found between the shoulder and the neck.  The AC joint pain will travel along the trapezius muscle which has attachments to the neck and the side of the head.

Trapezius muscle anatomy. AC joint pain will often follow course of this muscle.
The exam will also show classic signs of “impingement”, i.e. pain with forward elevation and rotation of the arm.  The plain x-ray will show narrowing, spur formation or degenerative findings of the AC joint.  If an MRI is done of the shoulder it will show edema and swelling around the AC joint. Another way to weed through the list of potential diagnoses is to inject the AC joint with Lidocaine with or without steroid. If the AC joint injection eliminates the pain, the doctor can confidently make the diagnosis of AC joint degeneration and not a cervical spine pathology. The final treatment for the shoulder/neck pain may be something as a simple steroid injection, stretching exercises, and physical therapy. In cases where nonsurgical treatment fails, a very simple arthroscopic distal clavicle resection also known as a Mumford and decompression procedure will cure the problem.

There are cases where the patient’s pain is from both the shoulder and the neck.  In these cases I will treat the shoulder first and if the pain continues I will recommend they move forward with the neck treatment.

I hope this information helps.  Please let me know if I can be of service.

Dr. Mora is a native of Orange County. He graduated from Anaheim High School in Orange County CA. He received his medical education at UC Irvine College of Medicine where he finished in the top of his class earning the coveted AOA Medical Society honors. He completed his Orthopedic Surgery training LAC+USC Medical Center and then did a additional Sports Medicine Fellowship at the Santa Monica Orthopaedic and Sports Medicine Group where focused on sports medicine, shoulder, knee, hip arthroscopy.   He has published numerous book chapters on the topics of ACL injuries in soccer players, cartilage restoration, and athletic hip injuries.   He is currently practicing Orthopedic Surgery in the City of Orange Orange County.  He is a founding partner at Restore Orthopedics and Spine Center ( Dr. Mora’s practice focus is on sports related trauma, MMA injury treatment, arthroscopy of the shoulder, hip, knee and elbow, regenerative medicine (PRP and Stem Cells), partial and total knee replacement. He sees athletes of all levels including professional soccer and UFC/MMA patients. Dr. Mora’s family heritage is Peruvian. He speaks fluent Spanish.

Check out my Profile on Yelp
For more info become a Fan!
Dr. Mora’s Twitter Link: 4000+ Followers
My Professional LinkedIn Profile


Restore Orthopedics and Spine Center
112o W. La Veta Ave, Third Floor
Orange, CA 92868

Office: (714) 332-5498
Fax: (714) 941-9539

Error: Contact form not found.

[slideshow_deploy id=’1142′]