AC (Acromioclavicular) Joint Separation
What Is a Separated Shoulder?
A separated shoulder — more precisely an AC joint separation — is an injury to the ligaments connecting the collarbone to the shoulder blade, usually from a direct fall onto the shoulder or an outstretched arm. It's a different injury than a dislocated shoulder, though the two are often confused. Mild separations typically heal without surgery; more severe separations, where the collarbone is significantly displaced, may benefit from surgical stabilization.
What's Actually Injured
The AC joint sits at the top of the shoulder, where the collarbone (clavicle) meets the shoulder blade (scapula). It's held together by several ligaments. A fall or direct blow to the shoulder — common in cycling accidents, contact sports, and falls onto the shoulder — can stretch or tear these ligaments, allowing the collarbone to shift out of its normal position.
Grading the Injury AC separations are graded on a scale (typically I through VI) based on how far the collarbone has displaced and which ligaments are torn. Lower grades (I-II) usually involve stretching or partial tearing and are managed without surgery. Higher grades (IV-VI) involve complete ligament disruption with significant displacement and more often require surgical stabilization, particularly in active or younger patients.
Recognizing the Symptoms
Pain and swelling directly over the top of the shoulder
A visible bump or step-off where the collarbone sits higher than normal
Pain with overhead movement or reaching across the body
Tenderness when pressing directly on the joint
Diagnosis:
A focused physical exam checking strength and specific movement patterns is often enough to suspect a tear. MRI is typically used to confirm the diagnosis, measure the size of the tear, and evaluate the quality of the remaining tendon and muscle — details that directly affect the surgical plan if surgery becomes necessary.
Treatment Options
Nonsurgical:
A sling for comfort, ice, activity modification, and physical therapy to restore motion and strength once acute pain settles — the standard approach for lower-grade separations, which generally heal well even without a perfectly restored joint appearance.
Surgical:
For higher-grade separations or in patients who remain symptomatic, surgical reconstruction restores the ligament support and repositions the collarbone, typically using a graft or strong suture-based fixation technique. This can sometimes be done arthroscopically.
Frequently Asked Questions:
Is a separated shoulder the same as a dislocated shoulder?
No — a separated shoulder involves the AC joint at the top of the shoulder, where the collarbone meets the shoulder blade. A dislocated shoulder involves the ball-and-socket joint itself. They're different injuries with different treatment.
Do all AC separations need surgery?
No. Most lower-grade separations heal well with nonsurgical treatment. Surgery is generally reserved for more severe, high-grade separations or for patients who remain symptomatic after conservative care.
How long does it take to recover from a separated shoulder?
Lower-grade injuries often improve significantly within 4-6 weeks. Higher-grade injuries treated surgically typically involve a longer recovery, often several months, to allow the reconstruction to heal fully.