Over the last several months we are seeing an increasing number of patients recovering from or requiring shoulder replacement surgery. Generally there are two types of shoulder replacement surgery. The first is known as a total shoulder arthroplasty (TSA) and the other is referred to as a reverse total shoulder arthroplasty (r-TSA). Which one you have or require depends on your particular set of circumstances and the condition of your shoulder at the time of surgery.
A traditional total shoulder replacement (TSA) is similar to the original anatomy in that the socket structure remains concave just like the original scapula and the ball remains round like the humeral head. Granted, the parts are usually plastic and titanium (there are a variety of metals), but the design mirrors the original equipment. Patients that have traditional total shoulder replacement surgery have a rotator cuff that can be repaired or attached in a way that will work with the new replacement parts. However, if both the ball and the socket are degenerated and destroyed, this damaged architecture will prevent normal motion. This is usually an older patient or it could be a middle-aged patient that has abused the shoulder through a combination of heavy weight lifting and a physical occupation. Patients that have a total shoulder replacement can expect a reduction in pain once the rehabilitation process is complete. However, it is rare for patients to achieve full range of motion following the replacement. So, total shoulder replacements are considered a salvage surgery primarily performed for pain relief. Any additional post-operative function should be considered a bonus. Another consideration is that some patients may develop deep periprosthetic infections anywhere from 2-weeks to 3-years after the surgery. A sign of the deep periprosthetic infection is pain that does not resolve with external treatments such as physical therapy. Like anything else, the best way to diagnose the infection is to suspect it.
Reverse total shoulder arthroplasty (r-TSA) commonly referred to as a reverse total shoulder replacement does just what it says: it reverses the anatomy of the shoulder. The ball is now attached to the scapula or shoulder blade where the socket once was. The socket is now attached to the upper arm. This type of replacement is performed for several different reasons or circumstances. If the patient’s shoulder is severely degenerated with an atrophied or severely torn rotator cuff, the r-TSA will allow the shoulder to leverage the larger Deltoid muscle and bypass the rotator cuff, if you will. If a patient has had a previous TSA and develops a deep periprosthetic infection, it is common for the surgeon to perform a revision surgery with the r-TSA. Patients that are offered r-TSA surgery do have a better chance to advance their range of motion beyond their restricted pre-operative range of motion. One common complication of the r-TSA is a stress fracture of the scapula where the prosthesis was attached. Receiving supervised post-operative rehabilitation can minimize this. Your physical therapist will progress you rehabilitation at a rate that will reduce the risk of post-operative fracture.
Some patients that have had a traumatic injury to their shoulder in their teens or twenties may experience early degenerative changes of the shoulder joint. An example would be if a young athlete experiences what is known as a Bankart injury involving a fracture of the socket and a torn cartilage and ligament. It is not uncommon for this injury to be repaired with screws leading to premature arthritic development. In these cases, it is possible to consider a shoulder resurfacing. This is a type of hemiarthroplasty that is a round cap placed over the existing ball. The resurfacing procedure is less invasive and preserves range of motion and activity level. Patients that have resurfacing can return to the majority of recreational and athletic activities that they enjoyed before their dysfunction.
If you are over the age of 50 and have been told you have a “frozen shoulder” you should inquire about the X-ray results. It is not uncommon for patients with a “stiff shoulder” to be labeled “frozen” when there is actually severe arthritic development causing the stiffness. By definition a “frozen shoulder” is an inflammation and stiffness of the ligaments with the bones underlying being of normal architecture. When the architecture is destroyed by severe degeneration or arthritic development, the stiffness no longer falls under the umbrella or “frozen shoulder” and has progressed to severe osteoarthritis. If your shoulder is stiff and restricted, the first step is a regular x-ray to take a good look at the boney architecture to make sure that ball is still round. If you have been told you need a shoulder replacement, be sure that your orthopedic surgeon offers all three types of replacements. This will ensure you get the one you need and not the one they want you to have.