By Dr. Paul D. Protomastro, M.D.
Arthritis is a common cause of shoulder pain and dysfunction that drives many people to need the care of an orthopaedic surgeon. The shoulder joint is formed by a ball on the upper end of the humerus bone that rotates within a small socket on the shoulder blade bone known as the glenoid. The surface of both the ball and socket are coated with a thin, frictionless lining known as articular cartilage. The gradual thinning and ultimate loss of the cartilage lining from the joint is known as osteoarthritis. Osteoarthritis more commonly affects the hips, knees and hands but it frequently affects shoulders. As the cartilage on the surface of the ball and socket joint wears out, the bones begin to rub and grind against one another causing inflammation, swelling, stiffness and pain. As these symptoms increase shoulder function gradually deteriorates. Thankfully mild to moderate shoulder arthritis is far better tolerated than that of the hip or knee, likely due to the non-weight bearing nature of the shoulder.
In the early stages of shoulder arthritis, a variety of non-operative treatments can decrease pain and improve function. Gentle stretching and strengthening in combination with over the counter pain medications such as Tylenol or Ibuprofen are often effective. If these simple measures fail to provide acceptable relief, injecting cortisone (steroids) into the shoulder joint is a safe and effective way to achieve significant yet temporary pain relief by decreasing inflammation. Injection of joint lubricant (Hyaluronic Acid, eg. Synvisc) into the shoulder is currently under investigation as a means of decreasing pain and improving function, however, the safety and efficacy of this treatment has yet to be determined. Alternative treatments such as oral supplements (Glucosamine and Chondroiton Sulfate), acupuncture, massage, and rehabilitation (electrical stimulation, ultra-sound and supervised exercise) to reduce symptoms may also be effective.
When these simple measures prove insufficient and the pain and compromised function of shoulder arthritis become severe, surgery is a valuable option. Despite years and millions of dollars of research, there is currently no way to restore or regrow healthy cartilage on arthritic joint surfaces. Minimally invasive arthroscopic procedures to “clean out” and “smooth down” the joint surface are of minimal long term benefit and have largely been abandoned. The most reliable and effective way to restore a painless and frictionless surface to the shoulder ball and socket is a Total Shoulder Joint Replacement. Replacing (resurfacing) the arthritic bone ends with a metal-on-plastic artificial joint is a safe, common and durable way of eliminating pain and restoring function. Although hip and knee replacements are more common, shoulder replacements have successfully been performed in the United States for over 30 years. Breakthroughs in anesthesia, implant engineering and surgical techniques have made shoulder joint replacements safe, effective, and reliable when performed by Orthopaedic surgeons with appropriate training and experience.
A shoulder replacement is a major operation performed in an operation room under anesthesia. Through a 4-inch incision on the front of the shoulder, the socket is re-surfaced with a plastic dish and the top of the humerus is replaced by a metal ball mounted onto a metal stem placed down the middle of the humerus bone. One of the four rotator cuff tendons must be detached from the humerus to resurface the joint and it is repaired back to the humerus with sutures at the conclusion of the operation. In the hands of a trained and experienced shoulder specialist, the operation can be performed in about an hour with minimal blood loss and a very low risk of complication. A post-operative short stay in the hospital (1 to 2 days) for antibiotics, pain medication and physical therapy is typical. A sling to support and protect the shoulder is used for 3 to 4 weeks. Patients can resume elbow and hand use almost immediately. Outpatient physical therapy several times a week for 2 to 3 months is required to regain motion, strength and function.
For those who suffer the pain and disability of advanced shoulder arthritis, the benefits of shoulder replacement surgery far outweigh the risks. This major surgery carries the risk of infection, bleeding, nerve injury, anesthetic complications, stiffness, incomplete pain relief or residual limitation of function. The combined risk of complication following a shoulder replacement is under 5%. Over 95% of patients that undergo shoulder replacement achieve satisfactory pain relief and dramatically improved shoulder function. On average it takes 4 to 6 months to fully recover from a shoulder replacement. Over 85% of shoulders replaced in the last 15 years are still functioning well without need for subsequent treatment. The plastic and metal surface of joint replacements can wear out given enough time or abuse. Plastic surface wear can lead to loosening of the implants from the bone. If this occurs and symptoms return, revision surgery to re-implant a new ball and socket can be performed successfully.
People who suffer from shoulder pain, stiffness and diminished function should seek the help of an orthopaedist. The symptoms of shoulder arthritis can usually be minimized with medication, exercise and injections. If these simple treatments fail to provide sufficient or lasting relief then shoulder replacement is an effective, safe, durable and common way to eliminate pain and restore shoulder function.
