Health & Wellness News and Tips
Total Shoulder Replacement

Total shoulder replacement, also known as total shoulder arthroplasty (TSA), is a tremendously successful procedure for treating the severe pain and stiffness that often result at the end stage of various forms of arthritis or degenerative joint disease of the shoulder joint. The primary goal of shoulder replacement surgery is pain relief, with a secondary benefit of restoring motion, strength, function, and assisting with returning patients to an activity level as near to normal as possible. Many patients return to the sports they love like tennis, golf, and swimming, while also pursuing personal health initiatives such as individual training &  yoga.

Painful shoulder arthritis refers to the disappearance of the normally smooth cartilage surfaces of the shoulder, which permit the ball and socket to smoothly glide against one another. This disappearance of cartilage covering results in a “bone on bone” joint and can be quite painful. Thus new surfaces provide the answer for restoration of comfort

Anatomy

Your shoulder is made up of three bones: your upper arm bone (humerus), your shoulder blade (scapula), and your collarbone (clavicle). The shoulder is a ball-and-socket joint: The ball, or head, of your upper arm bone fits into a shallow socket in your shoulder blade. This socket is called the glenoid

The surfaces of the bones where they touch are covered with articular cartilage, a smooth substance that protects the bones and enables them to move easily. A thin, smooth tissue called synovial membrane covers all remaining surfaces inside the shoulder joint. In a healthy shoulder, this membrane makes a small amount of fluid that lubricates the cartilage and eliminates almost any friction in your shoulder.

The muscles and tendons that surround the shoulder provide stability and support.

All of these structures allow the shoulder to rotate through a greater range of motion than any other joint in the body.

Normal anatomy pic

The actual surgery involves replacing the damaged humeral head (or joint “ball”) with a metal ball, and putting a new smooth plastic surface on the glenoid (called the “socket”). [see Fig. 2] Metal on plastic surfaces (rather than metal on metal) are the hallmark of virtually all shoulder replacement implant systems. Partial shoulder replacement (or hemi-replacement) may also be indicated with certain severe shoulder fractures of the humeral head – where the native Glenoid is healthy & intact. This technique requires the replacement of the ball component only – which then articulates with the patients own Glenoid.

Osteoarthritis (Degenerative Joint Disease)

This is an age-related "wear and tear" type of arthritis. It usually occurs in people 50 years of age and older, but may occur in younger people, too. The cartilage that cushions the bones of the shoulder softens and wears away. The bones then rub against one another. Over time, the shoulder joint slowly becomes stiff and painful.

Unfortunately, there is no way to prevent the development of osteoarthritis. It is a common reason people have shoulder replacement surgery.


LEFT IMAGE: shows healthy shoulder with normal articular cartillage, RIGHT IMAGE: shows destroyed cartillage-the begining of osteoarthritis





LEFT IMAGE Shows: X-ray of a normal shoulder. RIGHT IMAGE Shows:X-ray of an advanced osteo arthritic shoulder:


Other causes

Rheumatoid Arthritis

This is a disease in which the synovial membrane that surrounds the joint becomes inflamed and thickened. This chronic inflammation releases chemical agents that destroy bone & cartilage -  eventually cause cartilage loss, pain, and stiffness. Rheumatoid arthritis is the most common form of a group of disorders termed "inflammatory arthritis."

Post-traumatic Arthritis

This can follow a serious shoulder injury. Fractures of the bones that make up the shoulder or tears of the shoulder tendons or ligaments may damage the articular cartilage over time. This causes shoulder pain and limits shoulder function.

Rotator Cuff Tear Arthropathy

A patient with a very large, long-standing rotator cuff tear may develop cuff tear arthropathy. In this condition, the changes in the shoulder joint due to the rotator cuff tear may lead to arthritis and destruction of the joint cartilage.

Unfortunately this is quite  common in our country &  particularly in Kerala as very often patients try Ayurveda first & sometimes eventually come so late for surgery – by which time  the rotator cuff muslces involved would have degenerated -  results in poor results even after repair.

Avascular Necrosis (Osteonecrosis)

Avascular necrosis is a painful condition that occurs when the blood supply to the bone is disrupted. Because bone cells die without a blood supply, osteonecrosis can ultimately cause destruction of the shoulder joint and lead to arthritis. Chronic steroid use, deep sea diving, severe fracture of the shoulder, sickle cell disease, and heavy alcohol use are risk factors for avascular necrosis.

Severe Fractures

A severe fracture of the shoulder is another common reason people have shoulder replacements. When the head of the upper arm bone is shattered, it may be very difficult for a doctor to put the pieces of bone back in place. In addition, the blood supply to the bone pieces can be interrupted. In this case, a surgeon may recommend a shoulder replacement. Older patients with osteoporosis are most at risk for severe shoulder fractures.

Failed Previous Shoulder Replacement Surgery

Although uncommon, some shoulder replacements fail, most often because of implant loosening, wear, infection, and dislocation. When this occurs, a second joint replacement surgery — called a revision surgery — may be necessary.


LEFT IMAGE:Shows the three components of a TOTAL SHOULDER IMPLANT SYSTEM.RIGHT IMAGE:Shows the three components attached and in position after a total shoulder replacement.


Reverse shoulder technique

In recent years, a new type of shoulder replacement, the "reverse" shoulder has entered the armamentarium of shoulder surgeons to treat arthritis.

The design rationale for the reverse shoulder replacement is based on the fact that since in nature the shoulder ball “rests against” the socket, rather than being deeply contained within the socket, it relies on the tendons surrounding the ball socket to both hold it in place and to move it. In some types of arthritis, these tendons are severely damaged, torn, or non functioning. Because of this, an anatomic shoulder has no soft tissue to hold it in place and or to move it.

The design of the reverse shoulder puts the ball on the patients own socket, and it is the plastic socket which is placed on the humerus bone. The reverse design has more stability and does not need the tendons to hold it in place. It also is moved by the deltoid muscle, not the rotator cuff tendon, so it is an ideal choice when the damaged shoulder needs new surfaces, but does not have healthy enough soft tissues for stabilization and movement.


X-ray showing reverse shoulder prosthesis in position.Note that the head/ball is on the upper side and the socket on the lower side which is "reverse" of that in a normal shoulder.This configuration medialises the centre of rotation there by permitting abduction(lifting arm) even when these muscles are weak



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