Reverse Shoulder Replacement: A Solution for Irreparable Rotator Cuff Tears

By Dr Christopher M. Phoon

MBBS BSc(Med) FRACS(Orth) FAOrthA

Orthopaedic Surgeon, Queenstown Joint Clinic

Understanding Irreparable Rotator Cuff Tears

It’s always upsetting to be told that your rotator cuff tear can’t be repaired. Many patients come to me after hearing those words and worry that there are no options left.

Rotator cuff tears are extremely common, particularly as we age. They’re part of the normal wear and tear of life — no different from getting grey hair or wrinkles.

For most people, these tears cause mild pain or weakness. But in some, the tendons tear so completely that the shoulder develops a condition called rotator cuff arthropathy — a combination of tendon failure and arthritis. This leads to chronic pain, weakness, and difficulty lifting the arm above shoulder height.

It can be disheartening to hear, “you’re too old for surgery,” but that’s no longer true. There is an excellent solution — the reverse total shoulder replacement.

Normal Shoulder and Rotator Cuff Anatomy

To understand the concept of a reverse shoulder replacement, it helps to first know how the shoulder normally works.

A normal anatomic type shoulder replacement - needs an intact rotator cuff

The shoulder is a ball-and-socket joint:

• The ball is the top of the arm bone (the humeral head).

• The socket is a shallow cup on the shoulder blade (the glenoid).

This design gives us remarkable range of motion — more than almost any other joint — but it relies on the rotator cuff muscles and tendons to centre the ball in the socket and keep the joint stable.

When the rotator cuff fails, the ball tends to ride upward, grinding against the bone above and causing painful loss of movement. Simply replacing the joint in the usual “anatomical” way doesn’t help, because without a functioning rotator cuff the new joint would still migrate upwards and become unstable.

How a Reverse Shoulder Replacement Works

A reverse shoulder replacement changes the geometry of the joint.Instead of placing the ball on the arm bone and the socket on the shoulder blade, the arrangement is reversed:

• The ball is fixed to the glenoid (shoulder blade).

• The socket is attached to the humerus (arm bone) and set slightly lower.

This design shifts the centre of rotation and increases the mechanical advantage of the deltoid muscle, which is usually still intact. The deltoid can then lift the arm efficiently, even without the rotator cuff.

The result is a shoulder that can once again raise, rotate, and function with far less pain.

Who Benefits from Reverse Shoulder Replacement

Reverse shoulder replacement is most commonly used for older patients with:

• Long-standing irreparable rotator cuff tears

• Rotator cuff arthropathy (arthritis from tendon failure)

It is not generally recommended for very young or highly active patients, as implant wear and long-term demands are different. But for those who have retired or have moderate activity levels, it’s often a life-changing procedure that restores independence and function.

Summary

• Irreparable rotator cuff tears are common and can cause pain and loss of motion.

• When the rotator cuff can’t be repaired, the shoulder loses its stability.

• Reverse shoulder replacement changes the joint orientation, allowing the deltoid to lift the arm again.

• It is an excellent solution for older patients with rotator cuff arthropathy, providing lasting pain relief and improved function.