Glenohumeral Joint arthritis is a common condition. Most people have heard of hip and knee replacements, but shoulder replacement is less common. In fact shoulder joint replacement is becoming more and more common, as results are being shown to be excellent. Historically treatment was limited, and therefore shoulder athritis perhaps neglected until the advent of modern joint replacement for the shoulder in the 1970’s with Dr Charles Neer in the USA. Actually, a shoulder replacement was probably the first ever joint replacement done, made of ivory and rubber, performed in France by a surgeon called Peon in around 1870.
What makes the shoulder unique is the variety of types of arthritis that affect it, and the fact that each type may require a different type of arthroplasty. Primary osteoarthritis for example usually has intact bone and normally functioning shoulder muscles and is therefore ideal for an anatomic prosthesis ie replacing anatomy like for like, with a metal humeral head (ball) and polyethelene (plastic) cup. Cuff tear arthritis however needs a different approach to compensate for loss of the muscles to increased stability and to allow the remaining muscles like the Deltiod to work better and “Reverse Geometry” prostheses are used in this situation. Rheumatoid arthritis can behave a bit like either of the above, and avascular necrosis (loss of blood supply to the bone) is quite a common cause of arthritis at the shoulder. Finally arthritis following shoulder Instability is a common cause of arthritis, and shoulder instability is a common condition which often affects young patients.
Our current situation is that we have a great variety of 3rd and 4th generation implants, anatomic, bone sparing and reconstructive which have proven good results over the last 10-20 years. These results seem to be as good as Hip and Knee replacement. An exciting move in the UK is the inclusion of Shoulder and Elbow replacement on the National Joint Registry. This will include data of clinical scores for the first time and will be invaluable in monitoring individual implants, patient outcomes, and soon individual surgeon outcomes as well.
By Philip Ahrens