Shoulder replacement surgery is performed to replace the damaged parts of the shoulder joint with prosthetic components (prostheses) in order to relieve pain and improve functionality. The goal of the surgery is to reduce pain, improve strength, restore range of motion, and enable better use of the shoulder and arm.
The shoulder is a ball and socket joint that is capable of a range of motion unmatched by any other joint in the body. It is composed of the clavicle (collar bone), scapula (shoulder blade), and humerus (upper arm bone), along with tendons, muscles, and ligaments that support and enable movement. The coordination between these components is key to the shoulder’s broad versatility in movement.
The clavicle connects with the shoulder blade at the acromioclavicular joint, linking the shoulder to the rib cage. The humerus, or upper arm bone, has a rounded head that fits snugly into the socket of the shoulder blade, forming the ball and socket structure of the joint, with cartilage covering the bone surfaces to ensure smooth movement. Muscles and tendons surrounding the shoulder not only provide stability and mobility but also help control the wide range of motion, while the synovial membrane inside the joint produces fluid to lubricate the cartilage and reduce friction.
The rotator cuff is made up of four muscles that stabilize the shoulder joint and assist with its movement. When a rotator cuff tendon tears, it can result in significant pain, instability, and limited of function in the shoulder. Such tears are commonly caused by traumatic events such as a fall, particularly in elderly individuals, or injuries resulting from high-impact sports. The treatment options depend on the tear’s size, location, and the patient’s overall health, including physical therapy, cortisone injection, and, if those fail, surgery.
The type of shoulder replacement surgery depends on your specific condition. There are five types of shoulder replacement: hemiarthroplasty, resurfacing hemiarthroplasty, anatomic total shoulder replacement, stemless total shoulder arthroplasty, and reverse total shoulder replacement. Hemiarthroplasty involves replacing just the ball and stem of the joint, leaving the natural socket intact. Resurfacing hemiarthroplsty focuses only on capping the joint surface of the humeral head with a prosthetic cap, preserving the natural bone structure. Anatomic total shoulder replacement involves both the ball and socket being replaced with a polished metal ball attached to a stem on the humeral side and a plastic cup on the glenoid socket. Stemless total shoulder arthroplasty is a more bone-preserving option where the ball is attached directly to the humerus without using a stem. Reverse total shoulder replacement, used primarily in cases of severe rotator cuff injury, reverse the anatomy of the shoulder by placing the metal ball in the socket and the plastic cup on the upper arm bone, allowing for improved movement despite damaged rotator cuff muscles.