A painful thickening at the top of the shoulder

You paint a ceiling with your arm raised overhead and feel a sharp, pinpoint pain exactly where the collarbone joins the shoulder.

You reach for your phone from the passenger seat and the same spot hurts again. With your finger you can feel a hard, slightly painful thickening. This is not ordinary ‘shoulder fatigue after a day at work.’ These are probably degenerative changes of the acromioclavicular joint.

What is actually happening?

Despite its small size, the acromioclavicular joint carries considerable loads every time the arm is raised, like a small bearing supporting a much larger machine. As cartilage wears away, osteophytes—bony growths—develop at the joint edges and can be felt as a hard thickening under the skin. The damaged surfaces rub together, causing the most pain when the arm is at its extremes: high overhead or across the body.

These changes often appear without a specific cause, simply associated with age, usually after forty. They may also be secondary to an old joint injury or years of repetitive overhead arm movements, common in tennis players, volleyball players, and people who train with weights.

How can you recognize it?

  • pinpoint pain and a hard thickening on top of the shoulder, where the collarbone joins the shoulder blade,
  • pain worsens when you raise the arm overhead,
  • pain also appears when reaching across the body, for example for something on the adjacent seat,
  • grinding that can be felt in the joint during arm movements.

Why you should not wait

IMPORTANT: the disease itself and its severity usually do not threaten shoulder function, and pain sometimes resolves on its own even when changes remain visible on imaging. Nevertheless, do not delay diagnosis, because similar pain can also be caused by other shoulder problems requiring completely different treatment.

A neglected joint remains chronically inflamed, and pain may limit shoulder function, making everyday activities and exercise difficult.

How we help

We begin with a consultation, X-ray, and ultrasound. The X-ray shows the condition of the cartilage and joint space, while ultrasound assesses the soft tissues around the joint and helps confirm that the pain comes from this joint rather than neighboring shoulder structures.

We always begin treatment conservatively: by limiting painful movements, using anti-inflammatory medication, and sometimes briefly relieving the arm. An anti-inflammatory injection directly into the joint may be a necessary step before surgery, but repeated too often it can further weaken the cartilage.

When pain is severe, especially at night, and limits arm function despite conservative treatment, we surgically remove the altered end of the collarbone that causes the pain. 

There is one goal: a shoulder in which the acromioclavicular joint is no longer a troublesome problem.

Book a consultation

If you recognize these symptoms, make an appointment to be sure that this is the affected joint and not another, more serious shoulder problem. We will determine where the pain comes from and tell you which treatment makes sense in your case.