Reverse Total Shoulder Replacement
What is it?
A reverse shoulder arthroplasty is a special type of shoulder replacement that is used in patients with large and irreparable rotator cuff tears associated with arthritis of the ball and socket joint of the shoulder. Sometimes it is also used to treat severe fractures of the shoulder or in revision surgery. It is called a reverse shoulder arthroplasty because the ball and socket are "reversed" when the new joint is placed. The original socket is replaced with a metal ball, and the original ball is replaced with a highly engineered plastic socket. This type of replacement has been approved for use in the United States since 2004 but has been used in Europe for decades. It is a unique shoulder replacement that gives patients a good treatment option for problems that were difficult to treat in the past.
How is it performed?
A reverse shoulder replacement is performed through an incision on the front of your shoulder. We are able to spread most of the muscles out of the way to expose the shoulder joint. Only one muscle, a rotator cuff muscle (subscapularis), needs to be detached in order to access the joint if it is still intact. It is repaired if possible at the end of the surgery. All bone spurs are taken out and the arthritic surfaces are removed. A new metal ball is placed over your old socket and secured with screws. A plastic socket placed in the region of your old ball and secured into place with a stem that fits snugly in the central canal of the arm bone. An x-ray of a reverse replacement is shown here
What are the risks?
Major medical complications are uncommon during the peri-operative period of a reverse shoulder replacement, but they can occur. We screen patients carefully to ensure that they are at minimal risk for any of these complications. Aside from routine surgical and anesthetic risks (bleeding, infection, anesthesia side effects...), below are some of the most common risks associated with a shoulder replacement:
Shoulder instability: Post-operative instability of the a reverse shoulder replacement occurs more often than in a routine shoulder replacement. It does not occur commonly but, if it does occur, it typically happens in the early post-operative period and may require more surgery to put the shoulder back in place.
Nerve Injury: Nerve injury following reverse shoulder replacement is typically related to stretching of the nerves. The arm is lengthened slightly after a reverse replacement and this sometimes puts tension on the nerves. Most injuries are subtle and typically recover with time.
Implant wear and loosening: The implant can wear over time, just like the tread on your car tires. This can potentially lead to loosening of the components. This takes 10-15+ years to develop in most patients.
Acromial Stress Fracture: Similar to nerve injury, the lengthening of the arm can place increased stress on the acromion, the bone which sits on top of the ball and socket joint. On rare occasions, this increased stress can lead to a small stress fracture of this bone. Often, this can be managed conservatively but occasionally this can require additional surgery.
How do I know if I need a reverse shoulder replacement?
The best candidates for this type of replacement are patients who have arthritis of the shoulder with a large rotator cuff tear that is not reparable. Patients often present with pain in the shoulder and great difficulty raising their arm above their head.
X-rays and examination are typically all that is needed to diagnose you with shoulder arthritis associated with a rotator cuff tear. Occationally, a CT scan or MRI may be ordered to confirm the diagnosis or to evaluate bone wear. Typically, the ball will demonstrate instability in the superior direction since the rotator cuff is not there to provide stability. There may also be evidence of wear on the acromion (the bone on the top of the shoulder)
Other common indications for surgery include severe fractures of the shoulder and failed shoulder replacements.
What are the expected results
In general, reverse shoulder arthroplasty is excellent at relieving the pain associated with shoulder arthritis and improving the overhead motion of the shoulder. It does not typically improve rotational motion of the shoulder significantly. However, most patients have the ability to comfortably perform day to day activities and many get back to activities such as golf, tennis, and gardening. Because rotational motion is not restored with this procedure, there may be some lingering inability to reach up your back for activities such as tucking in your shirt or fastening a bra. Additionally, a reverse shoulder is not built to withstand heavy manual labor, lifting, or impact. Patients who wish to continue to perform some of these activities may be better candidates for a hemiarthroplasty (partial shoulder replacement). However, for patients looking for relief of their pain and improved ability to get their arm overhead, a reverse shoulder replacement can be a good option for them.
How long is the recovery?
Patients typically stay in the hospital about 2 nights. Many patients are off all pain medications by their first post-operative appointment. The early recovery (<6 weeks) is focused on allowing the shoulder to heal and preventing early post-operative instability. The middle of the recovery (6-12 weeks) is focused on regaining shoulder strength and improving motion. The end of the recovery (>12 weeks) is focused on functional strengthening to get you back to the activities you desire. For many patients, formal physical therapy is not required. After 12 weeks there are no specific restrictions on the shoulder but it can take >6 months to achieve a full recovery.
Who is not a good candidate for a reverse shoulder replacement?
While a reverse total shoulder arthroplasty general provides predictably good results following surgery, there are some patients in which the results of a total shoulder are less predictable. These include the following types of patients:
- Patients on chronic pain medications
- Patient with neurologic injury involving the shoulder
- Patients with poor deltoid function from prior surgery
- Patients in poor general health and physical conditioning
While having any of these conditions does not mean that a reverse shoulder arthroplasty cannot be performed, it could mean that alternative methods of treatment may be safer and more predictable.