Glenoid Osteoplasty

Posterior glenoid osteoplasty for unstable dislocating shoulders. Surgery to build up the back of the glenoid socket using an osteotomy and graft can restore shoulder anatomy and lessen pain and improve function

Last updated: November 2, 2010
Edited by:

Winston J. Warme, M.D.
Winston J. Warme, M.D.,
Associate Professor,
UW Orthopaedics & Sports Medicine
Frederick A. Matsen III, M.D.
Frederick A. Matsen III, M.D.,
UW Orthopaedics & Sports Medicine

If you have questions regarding the ream and run procedure, feel free to email Frederick A. Matsen III M.D. at


A common cause of posterior dislocations and posterior instability of the shoulder is the loss of the rim or lip on the back of the socket of the shoulder joint. The posterior glenoid concavity can be restored by a procedure known as posterior glenoid osteoplasty.

Characteristics of posterior shoulder instability

The normal shoulder is a marvel of mobility and stability. It provides more motion than any other joint in the human body yet the humeral head (ball of the shoulder joint) remains precisely centered in the glenoid (the socket of the joint) throughout the wide range of shoulder activities. One of the main stabilizing mechanisms is concavity compression in which the head of the humerus is held into the glenoid concavity by the action of the rotator cuff (much like a golf ball is held into the concavity of a golf tee) (see figure 1). Because of this concavity the humeral head must rise up over the glenoid lip before it can translate out of the socket. The path taken by the humeral head during this translation is called the "glenoidogram" (see figure 2).

When the rim at the back of the socket is underdeveloped or worn the humeral head can translate out the back of the joint more easily without having to lift up over the rim. In this situation the glenoidogram becomes flattened (see figure 3).

Possible benefits of posterior glenoid osteoplasty

When recurrent posterior instability or dislocations interfere with the comfort and security of the shoulder and when these symptoms cannot be controlled by other means a posterior glenoid osteoplasty performed by an experienced shoulder surgeon can usually restore the stability of the joint (see figures 4 and 5).

Rehabilitation Video Clips

Click on an image below to play the video.

Getting the arm up to rotatewhile lying down - The goal is for the shoulder to rotate the arm fully with the elbow at the side--from full external rotation to full internal rotation. As these exercises become comfortable specific strengthening exercises are added especially in external rotation (see figure 25).
Isometrics for external rotation of the shoulder
Tubing for external rotation of the shoulder.
Free weights for external rotation of the shoulder.

At the end of six weeks and after a comfortable rotation and strength have been achieved the patient starts using the arm out to the side and then in increasingly forward positions as specified by the surgeon.

The strengthening exercises are continued for a year after surgery to optimize the dynamic stability of the shoulder.

Can rehabilitation be done at home?

In general the exercises are best performed by the patient at home. Occasional visits to the surgeon or therapist may be useful to check the progress and to review the program.

Usual response

Patients are almost always satisfied with the increases in range of motion comfort and function that they achieve with the exercise program. If the exercises are uncomfortable difficult or painful the patient should contact the surgeon promptly.

Rehabilitation Risks

This is a safe rehabilitation program with little risk.

Duration of rehabilitation

The strengthening exercises are continued for a year after surgery to optimize the dynamic stability of the shoulder.

Returning to ordinary daily activities

In general patients are able to perform gentle activities of daily living with the operated arm at the side starting two to three weeks after surgery. Walking with the arm protected is strongly encouraged. Driving should wait until the patient can perform the necessary functions comfortably and confidently. This may take up to one month if the surgery has been performed on the right shoulder because of the increased demands on the right shoulder for shifting gears.

With the consent of their surgeon patients can often return to activities such as swimming golf and tennis at six months after their surgery.

Stressful activities and activities with the arm in extreme positions must be avoided until six months after the surgery and then only if the shoulder is comfortable and strong.

Long-term patient limitations

Patients should avoid activities that involve major impact (chopping wood contact sports sports with major risk of falls) or heavy loads (lifting of heavy weights heavy resistance exercises) until one year after surgery and until the shoulder has excellent strength and range of motion--essentially equivalent to the opposite side. In this way the risk of re-injury is minimized.

Rehabilitation Costs

The surgeon and therapist should be able to provide the information on the usual cost of the rehabilitation program. The program is quite cost-effective because it is heavily based on home exercises.

Summary of posterior glenoid osteoplasty for posterior shoulder instability

In the hands of an experienced surgeon posterior glenoid osteoplasty can be a most effective method for restoring comfort and function to a shoulder with recurrent posterior instability dislocations or apprehension in a healthy and motivated patient when these symptoms do not respond to a supervised exercise program.

The best results are obtained when the surgery restores a deficient posterior lip to the shoulder socket (glenoid). In this situation the surgeon has a good opportunity to reconstruct the specific abnormality causing the instability.

Pre-planning and persistent rehabilitation efforts will help assure the best possible result for the patient.