Ream and Run non-prosthetic glenoid arthroplasty for shoulder arthritis: Regenerative cementless surgery designed for individuals desiring higher levels of activity than recommended for traditional total joint replacement.

Edited By: Frederick A. Matsen III, M.D., Winston J. Warme, MD
Last updated Monday, June 23, 2008

Figure 1 - Humeral head that has been damaged by arthritis.

Figure 2 - Artificial components of a shoulder replacement.

Summary

What are the key points about non-prosthetic glenoid arthroplasty for arthritis of the shoulder?

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Non-prosthetic glenoid arthroplasty, sometimes called the "ream and run" procedure, is a surgical treatment that can help relieve the pain from severe arthritis of the shoulder. Unlike conventional "metal on plastic" total shoulder replacement (total shoulder arthroplasty), the "ream and run" approach may allow active patients to remain involved in fitness, recreational, and vocational pursuits that would risk premature failure if traditional total shoulder arthroplasty were to be performed.

The shoulder is a ball and socket joint that allows the arm to be placed in an incredibly wide range of positions during every day activities. The ball is formed by the head of the humerus (arm bone), and the socket is formed by the scapula (shoulder blade). The socket is also referred to as the glenoid. The surfaces of the ball and socket are formed by cartilage, a tissue that allows joints to glide in a smooth and frictionless way.

Arthritis of the shoulder is a condition in which the cartilage on the humeral head and glenoid deteriorates. As this process becomes more advanced, the joint surfaces become rough, and areas of bone may be exposed. Figure 1 shows the surface of a humeral head destroyed by arthritis. Motion of the arthritic joint causes the surfaces to grate rather than glide. Progressive joint destruction makes the shoulder stiff, painful and unable to carry out its normal functions.

When pain and loss of function become disabling enough for a patient to consider treatment, joint replacement surgery is the most reliable solution for shoulder arthritis. The goals of shoulder replacement are to restore comfort and function to the joint by removing scar tissue, balancing muscles, and replacing the destroyed joint surfaces with artificial ones.

The artificial components of a typical shoulder replacement include the humeral ball (which is made of metal) and the glenoid component (which is made of plastic). These are depicted in figure 2. The humeral ball is fixed to the humerus (arm bone) by attachment to a stem that rests securely inside the hollow canal of the bone. The glenoid component is fixed to the shoulder blade using a small amount of bone cement.

While total shoulder replacement surgery has proven to be a successful treatment for advanced shoulder arthritis, the artificial components are not designed to withstand some of the demands that active individuals expect to place on them once comfort and function have been restored. As more and more people continue participation in sports and other recreational activities into their older years, they may slowly begin to exceed the limits of what the artificial components can tolerate.

This is particularly true for the plastic socket that is prone to wear out, loosen or even break in very active individuals. Patients who intend to return to activities that place physical demands on the shoulder replacement (such as golf, tennis, skiing, weightlifting etc.) may therefore be at risk for eventual failure of the artificial shoulder socket. When failure of the socket occurs, patients typically experience a dramatic decrease in their comfort and function.

Therefore, a conventional total shoulder replacement, which resurfaces the arthritic socket with a plastic component, may not be the best option in terms of preserving comfort and function in very active patients. In these patients, an alternative that removes the destroyed cartilage and provides a smooth and stable surface without insertion of the plastic socket may be more sensible.

This alternative is referred to as shoulder hemiarthroplasty with non-prosthetic glenoid arthroplasty. In this procedure, the humeral head is replaced with a metal ball in the exact same manner as a regular shoulder replacement. The socket is not replaced but is refinished in way that gives it a smooth surface and a shape which matches that the humeral ball. This process can also reorient the direction of the socket when it is pointing too far toward the back as a result of bone erosion.

Because the socket side of the joint is reshaped and the ball side replaced, the rough arthritic surfaces are eliminated from both sides of the shoulder joint. By avoiding the use of a plastic socket, non-prosthetic glenoid arthroplasty removes the risk of loosening or wear of the polyethylene component Because problems with the metal ball are very rare, this procedure should improve the longevity of comfort and function in patients who might otherwise experience earlier problems related to socket loosening or wear.

This procedure has proven successful in restoring comfort and a high level of shoulder function in patients with severe shoulder arthritis. The recovery of comfort may take longer than with conventional total shoulder arthroplasty, however. Like a conventional shoulder replacement operation, it is a highly technical procedure and is best performed by a surgical team who performs this surgery often. Such a team can maximize the benefit and minimize the risks. The two-hour procedure is performed under general (or nerve block) anesthesia.

• JBJS Article on Ream and Run (PDF) (0.8 MB)
• JBJS Article on Glenoid Component Failure in Total Shoulder Arthroplasty (PDF) (2.01 MB)

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Surgery for Arthritis of the Shoulder at the University of Washington

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