Overview
The acromioclavicular (AC) joint sits at the very top of the shoulder. It is where the outer end of the collarbone (clavicle) meets a bony shelf on the shoulder blade called the acromion. The joint is small and does not move much, but it works in nearly every overhead and across-body move the shoulder makes. Over time the cartilage lining the joint wears away. A direct blow, repeated heavy lifting, or simply aging can all play a part. The result is bone rubbing on bone. That hurts with cross-body movements: reaching across to buckle a seatbelt, pressing exercises, and overhead lifting.
Distal clavicle excision removes a small amount of bone from the worn outer end of the collarbone. This creates a small gap that fills with scar tissue. The grinding contact is gone, and the ligaments that hold the AC joint steady are left intact. The surgery can be done through small camera incisions (arthroscopy) or as open surgery. It is often done along with a rotator cuff repair or another shoulder surgery when AC joint pain is also present.
How the Procedure Works
We reach the AC joint with the camera and use a small bone-shaving tool (a burr) to remove bone from the end of the collarbone. We take just enough to stop the contact without making the joint unstable. Removing too little leaves the pain behind. Removing too much risks a loose, unstable collarbone. At the end we check cross-body motion. If the collarbone still touches the acromion in that position, we remove a bit more. The main ligaments that hold the collarbone steady are never touched.
When to Consider Distal Clavicle Excision
We generally offer distal clavicle excision when symptoms, imaging, and a full course of non-surgical care all point to surgery as the next step. The typical picture includes:
Symptomatic AC joint arthritis
Pain at the top of the shoulder, confirmed on imaging. It is worse when you bring your arm across your body, like reaching to the opposite shoulder.
Failure of conservative care
Activity changes, anti-inflammatory medicine, and at least one AC joint injection that did not give lasting relief.
Pain with overhead or cross-body use
A limit that affects daily activity, work, or sport.
Treats: AC Joint Arthritis
Risks & Why We Still Recommend It
Every operation carries risk. This procedure is offered because the condition, when left untreated, can cause lasting pain at the top of the shoulder with bench press, overhead work, and cross-body motion. The decision to proceed weighs the risks of surgery against the limitations the condition places on daily function. Surgery does not remove risk; it addresses a problem that is otherwise progressive. Whether it is appropriate is determined for each patient in consultation with the surgeon.
The risks we discuss with you before distal clavicle excision include:
- bleeding and infection
- anesthesia risk
- pain that stays if the AC joint was not the true source of the pain
- removing too much bone, which can leave the joint unstable
- removing too little bone, with continued pinching and pain
- stiffness
Surgery makes sense when AC joint arthritis is confirmed and injections and activity changes have not given lasting relief. If that picture does not fit you, we do not offer this operation.
Frequently Asked
questions we hear in clinicWhat exactly is the AC joint?
It sits at the very top of the shoulder, where the outer end of the collarbone meets a bony shelf on the shoulder blade called the acromion. The joint is small and does not move much, but it works in nearly every overhead and across-body move the shoulder makes, which is why arthritis there hurts with seatbelts, pressing exercises, and overhead lifting.
How much bone is removed?
A small amount from the outer end of the collarbone. We take just enough to stop the bone-on-bone contact without making the joint unstable. At the end of the operation we check cross-body motion, and if the collarbone still touches the acromion, we remove a bit more.
Will my collarbone be loose afterward?
The main ligaments that hold the collarbone steady are never touched, and the amount of bone removed is kept small for exactly this reason. The gap that is created fills with scar tissue, so the grinding contact is gone but the joint stays stable.
Do I have to try other treatments first?
Yes. Surgery is offered after activity changes, anti-inflammatory medicine, and at least one AC joint injection have not given lasting relief, and after imaging confirms the arthritis.
Is this open surgery or done with a camera?
It can be done either way: through small camera incisions (arthroscopy) or as open surgery. It is often done along with a rotator cuff repair or another shoulder surgery when AC joint pain is also present.
What are the main risks?
Bleeding and infection, anesthesia risk, pain that stays if the AC joint was not the true source, removing too much bone (which can leave the joint unstable), removing too little (with continued pinching), and stiffness. The full picture is in the Risks section above.
Further Reading
External patient-education references and related OSI pages for additional background:
