Shoulder Osteoarthritis

How does it typically present?

Pain in the shoulder and upper arm that comes on gradually. The pain is typical when the shoulder is moved and is accompanied by grinding, and in advanced stages also by restricted movement. The pain can also appear at night, but the typical pain is with movement.

Cartilage wear is typical of older age, usually above 60. However, it can also appear at a young age, even in the 30s. It is a process that develops gradually over a long period (unlike frozen shoulder, which is typical of a younger age and in which the restriction of movement develops quickly). The two conditions are told apart with an X-ray.

What is cartilage wear?

Cartilage is a special tissue found in joints that move. The unique properties of joint cartilage allow the surfaces to move smoothly with extremely little friction. Wear is the result of cartilage disease combined with load, and sometimes also the result of a past injury.

Joint cartilage cannot repair itself, so the process is irreversible and progresses over time. The cartilage loses its ability to allow smooth movement, and the bones rub against each other.

This friction leads to:

• bone growth at the margins
• restricted movement
• and of course pain and deformity of the shoulder

Cartilage wear is very common in the hip and knee joints, and less common in the shoulder.

How is cartilage wear diagnosed?

The diagnosis is suspected from the symptoms and the physical examination. To confirm the diagnosis, a plain X-ray is usually enough.

To decide on treatment, additional tests are needed whose purpose is:

• to assess the extent of the damage to the bone
• to check whether there is also damage to the shoulder muscles
• and, if surgery is chosen, to plan the operation

If surgery is planned, a CT or MRI usually needs to be done, at the discretion of the operating surgeon.

How is cartilage wear treated?

Cartilage tissue cannot heal, and at present there is no treatment that can restore damaged cartilage.

In early stages it is possible:

• to give anti-inflammatory medication, in an attempt to slow the process and treat the pain
• to give a cortisone (steroid) injection
• or to inject substances that replace joint fluid (hyaluronic acid)

Either way, these treatments can only give temporary relief. They:

• cannot stop the process
• and certainly cannot restore the cartilage

When the pain persists, and especially if there is also significant loss of function, surgery to replace the joint should be considered.

Note that none of these treatments heals the cartilage; at most they relieve pain. Joint replacement surgery solves the problem of pain and restricted movement.

What is the surgical treatment for cartilage wear?

The goal of treatment is first and foremost to reduce pain. Usually the range of motion can also be improved.

There are several options for replacing the shoulder joint:

1. Anatomical total replacement
In the operation the damaged cartilage surface is removed and an artificial joint is implanted: on the side of the head of the humerus a metal implant, and on the side of the glenoid a plastic surface (usually polyethylene).

2. Partial replacement
In some cases it is enough to replace only the head of the humerus, without placing a plastic surface opposite it. In this case it is a partial replacement of the joint.

3. Reverse total shoulder replacement
When, in addition to the damage to the cartilage, there is:

• marked deformity of the glenoid bone
• or damage to the rotator cuff tendons

In this situation a replacement with a standard implant is not possible, and a reverse shoulder implant is needed. This is the preferred implant for an older person, and usually, in any case of a patient above age 70–72, a reverse replacement will be performed.