Rotator Cuff Tear Arthropathy

Rotator cuff tear arthropathy is a condition that occurs when there is severe shoulder arthritis in the setting of a large rotator cuff tear. In order to be considered rotator cuff tear arthropathy, three clinical findings must be present:

1. Insufficient function of the rotator cuff (typically a large tear)
2. Arthritis of the ball-and-socket (glenohumeral) joint
3. Shifting of the normal position of the ball within the socket (superior migration)

Rotator Cuff Function

The rotator cuff is the group of four muscles and tendons that surround the ball-and-socket shoulder joint. These muscles serve several important functions, such as motion and strength of the shoulder. Another critical function of the rotator cuff is to provide a compressive force that holds the ball within the socket of the shoulder.

When the rotator cuff is not functioning properly, the mechanics of the shoulder joint can be altered. Much like having your car wheels out of alignment can cause abnormal wear of the tires, having the rotator cuff damaged can cause the ball and socket of the shoulder to have altered alignment. Once the alignment is shifted (the humeral head, or ball of the ball-and-socket joint, shifts upward), the shoulder joint tends to wear out unevenly. This wearing out of the cartilage leads to the loss of the normal smooth cartilage lining of the joint.

Causes

The condition of rotator cuff tear arthropathy develops over years. Typically, people have a rotator cuff tear without even knowing it. Over time, the effect of the rotator cuff tear alters the mechanics of the shoulder joint, leading to the development of arthritis. Rotator cuff tear arthropathy is not a condition that develops suddenly.

Sudden, acute injuries can lead to the occurrence of a rotator cuff tear, and can also cause cartilage damage within the shoulder joint. However, while factors such as previous injury may contribute to the development of rotator cuff tear arthropathy, the condition is really a chronic, slowly developing, long-standing problem. Once rotator cuff tear arthropathy has developed, trying to restore normal anatomic function at the shoulder is generally not possible. The options for treatment are focused either on optimizing the current function of the shoulder, or on replacement surgeries.

Symptoms

The signs of this condition are similar to normal shoulder arthritis, but there is often more weakness of the shoulder. Symptoms include:

• Shoulder pain
• Loss of mobility
• Weakness of the shoulder joint
• Swelling around the shoulder
• Atrophy of the musculature around the shoulder

Some people who have rotator cuff tear arthropathy have very severe symptoms that impair functioning of normal daily activities, while others may only have mild symptoms that do not interfere with their activity level. Symptoms tend to be more noticeable when they are on the dominant extremity, and symptoms tend to be more noticeable in people who have higher functional demands.

Diagnosis

The diagnosis of rotator cuff tear arthropathy can be made based on examination findings, as well as the results of tests that assess shoulder anatomy. A physical exam will generally reveal findings of arthritis that may include stiffness of the shoulder and difficulty with certain movements. Rotator cuff function can be evaluated by specific maneuvers that isolate the function of the particular muscles of the rotator cuff.

Imaging studies will show signs of arthritis and signs of rotator cuff damage. Despite not being able to see the rotator cuff on a regular X-ray, rotator cuff tear arthropathy is often quite apparent based on findings of advanced arthritis of the shoulder joint as well as abnormal positioning of the ball within the socket of the shoulder. The cause of the abnormal alignment seen on X-ray is the result of the insufficient function of the rotator cuff. For that reason, other imaging studies, such as MRIs or ultrasounds, may not be necessary. When there is a question of rotator cuff function, these imaging modalities can help clarify the situation.

Treatment

Rotator cuff tear arthropathy can create a challenging treatment problem. While shoulder replacements are an effective treatment for shoulder arthritis, the standard implants rely on the rotator cuff to function properly. Just as the normal shoulder relies on proper functioning of the rotator cuff, a standard shoulder replacement also relies on the function of the rotator cuff. When the rotator cuff is not working and a standard shoulder replacement is performed, the joint is abnormally aligned, and the socket portion of the replacement tends to loosen and wear out quickly. 

When rotator cuff tear arthropathy exists, a special type of implant is often used. One type of implant created for rotator cuff tear arthropathy is called a reverse shoulder replacement. This type of implant is designed to place a ball within the socket of the shoulder and forms a new socket on the top of the arm bone (the humerus). This design alters the mechanics of the shoulder joint, such that it is not necessary to have a functioning rotator cuff.

A Word From Verywell

Not every rotator cuff tear is the same, and there are certain situations that need to be addressed differently. One of these situations is rotator cuff tear arthropathy. Because of the coexistence of arthritis in the shoulder joint with the rotator cuff tear, treatment must take into account both of these conditions. Failure to recognize rotator cuff tear arthropathy can lead to ineffective treatment of your shoulder pain.