Stemless Total Shoulder Replacement

Introduction

When the shoulder joint is affected by arthritis, the cartilage lining the articulating bones breaks down. This causes the bones to rub against each other leading to pain and inflammation.

Advanced arthritis can make it difficult for you to move or lift your arm and carry out various activities. The pain can even interfere with sleep.

To treat advanced arthritis your doctor may recommend a total shoulder arthroplasty, also called a total shoulder replacement.

The shoulder is a ball-and-socket joint. The ball is formed by the end of the upper arm bone and the socket is formed by the shoulder blade. In a total joint replacement, both the ball and the socket portions of the joint are replaced by implants to create a new joint. While replacing the ball, traditional shoulder arthroplasty uses an implant with a stem that inserts into the canal of the upper arm bone. This can involve a lot of bone removal increasing the risk of a fracture. Another disadvantage is that such an implant is difficult to replace should a repeat procedure be needed in the future.

Stemless Total Shoulder Arthroplasty is a canal-sparing shoulder replacement surgery that does not use a stem implant. Instead, it is specifically designed to secure the implant with minimal loss of bone structure. 

Indications 

Stemless Total Shoulder Arthroplasty may be recommended if you have arthritis due to overuse, age, or trauma that is causing disabling pain in your shoulder and non-surgical treatments have not provided adequate relief.

Before the procedure, your doctor will perform an examination and ensure that you have a healthy bone to support the implant and no problems with your rotator cuff, the group of muscles that stabilize the shoulder joint.

Surgical Procedure

For the operation, you will be placed in a beach chair position. The shoulder joint is accessed through an incision between the shoulder and chest muscles. The joint is dislocated and the humeral head brought forward.

The size of the humeral head implant is determined preoperatively with the help of imaging studies and computer software. The humeral head is appropriately resected with the help of a guide or cutting block. The resected humeral head is compared with the trial head implants to further help with size determination.   

A positioning disc is used to prepare the resected surface of the humerus in order to properly orient the humeral implants. The disc is secured with 3 pins. A device called an Impactor is inserted into the bone through slots in the disc. With the impactor in place, the positioning disc is then removed and the humeral surface is protected while the glenoid surface is prepared.

To prepare the glenoid surface, a wire is inserted centrally through it and precisely orientated. A reamer is passed over the wire and the surface is reamed. A drill guide is then placed over the wire and two peg holes are drilled to anchor the glenoid implant. A trial implant is placed and tested. The final implant is fixed with cement. 

The trial humeral head implant is then fixed to the impactor in the humerus. Once in place, the shoulder joint is reduced and mobility is tested. The shoulder joint is then dislocated again. The trial implant and Impactor are removed. The final short stem implant is impacted into the bone and the final humeral head implant is fixed to it. Soft tissue repairs are performed and the incision is closed. Your arm is then placed in a sling.

Postoperative Care

The sling is removed the next day and the shoulder joint is mobilized. Certain movements and activities are restricted for a while during the healing process. Use of the arm is encouraged though for routine activities. You will begin shoulder strengthening exercises about eight weeks after the procedure and will gradually be able to tolerate more strenuous activities.

Advantages

Stemless Total Shoulder arthroplasty has the following advantages over traditional surgery:

• Placement of the implant is easier 
• Operating time is reduced
• Less blood loss
• Less pain after surgery with a faster recovery 
• More bone is preserved making it easier to repeat the procedure in the future.

Summary

Stemless Total Shoulder Arthroplasty surgery overcomes the disadvantages of traditional shoulder replacement surgery with less bone loss and a quicker recovery. As with any procedure, there are certain risks and complications. Your doctor will discuss whether the procedure is ideal for you.