Do You Need an Anatomic or Reverse Shoulder Replacement?

Shoulder pain can make simple tasks, like washing your hair, feel very difficult. Physical therapy, over-the-counter pain medication, and corticosteroid injections may ease the pain and restore some mobility. But those approaches aren't enough for the more than 100,000 people a year in the United States who decide to have anatomic or reverse shoulder replacement surgery.

To determine which type of surgery is right for you, two key considerations include the presence of arthritis in the joint and the health of your rotator cuff.

Arthritis occurs when you lose the cartilage that normally covers the joint surfaces. The rotator cuff is a band of tissue formed by four muscles and their attached tendons that hold the arm in place, helping to stabilize and move the shoulder. If your rotator cuff is functioning well, you can have a traditional, anatomic shoulder replacement; if it’s damaged, you might consider a reverse shoulder replacement (more on this procedure below).

“Patients may not know that these two options exist and that it’s possible to restore excellent function with either operation,” says Ken Donohue, MD, an orthopaedic surgeon and chief of Shoulder Reconstruction for Yale Medicine.

Both traditional and reverse shoulder replacement surgeries have been used for decades. They’re constantly improving, with longer-lasting materials such as pyrocarbon, 3D imaging that allows for precise implant placement during surgery, and custom implants for patients with unique anatomies.

Below, Dr. Donohue answers our questions about shoulder replacement surgeries.

The shoulder is a ball-and-socket joint that is normally lined by a protective covering called cartilage. The ball, or humeral head, is the rounded end of the upper arm bone called the humerus; the socket is a shallow, cup-shaped part of the shoulder blade called the glenoid. When the ball and socket are both lined by cartilage—and the mechanics are properly supported by muscles and tendons—the arm can move freely. When the joint loses cartilage or starts to lose the support of surrounding muscles or tendons, it can result in shoulder pain and restricted movement.

Shoulder arthritis and mobility issues are most common in people ages 60 and older, but they can affect people of all ages.

Arthritis can develop in any number of ways. It can result from using your arm repeatedly for a recreation and work-related activities. It can also come from an old injury, like one from a fall or other accident. Other causes of arthritis include rheumatoid arthritis (an inflammatory process affecting the joint) and avascular necrosis (a disease that occurs when blood supply to the bone is interrupted).

Both types of surgery replace a damaged or malfunctioning shoulder, with the goal of providing a pain-free shoulder that moves normally.

The surgery you choose will depend on several factors. These include the type of arthritis, the amount of joint damage, and the health of the rotator cuff.

• Anatomic shoulder replacement is the traditional type of surgery. It puts in a man-made shoulder that looks like a natural one. The socket connects to the shoulder blade, and the ball connects to the upper arm bone. Its use depends on having intact muscles and tendons that support the ball-and-socket operation.
• Reverse shoulder replacement: In this procedure, the joint’s ball and socket are swapped, so that the socket is attached to the upper arm bone and the ball is attached to the shoulder blade. “That's why it's called reverse—the joint anatomy is flipped,” says Dr. Donohue. This surgery may be done if the rotator cuff, which would normally support natural shoulder anatomy, is malfunctioning. A reverse shoulder replacement is designed so that the deltoid, a triangular muscle that makes the shoulder rounded, takes over the function of the rotator cuff.

Both types of operations relieve pain, but reverse shoulder replacement will also restore mobility for a patient who doesn’t have a working rotator cuff. For that reason, a reverse shoulder replacement is especially beneficial for people with chronic rotator cuff tears, which can happen gradually over a lifetime of repetitive lifting, or as the result of a previous injury to the shoulder.

A reverse shoulder replacement is also used if you have inflammatory arthropathy (any disease that affects the joints), rheumatoid disease, fracture, and other conditions.

Many people with these conditions have almost no shoulder mobility whatsoever—their arm is essentially stuck at their side, Dr. Donohue says. “For these people, reverse shoulder replacement is a miraculous innovation; before it became available, we had very little to offer to restore function. But now, people who haven't been able to move their arm for years can reach overhead within a few weeks after surgery.

Every patient’s situation is different, depending on factors such as age, health status, and the reason for having shoulder surgery.

But, in general, both traditional and reverse shoulder replacements are performed in the hospital and usually take less than two hours. Shoulder surgery usually requires general anesthesia. Patients often go home the same day or stay overnight in the hospital.

The first step—in advance of the surgery—is often 3D surgical planning, which involves CT scan imaging of the affected shoulder. Then, the results are analyzed by specialized digital software to create a 3D representation of the patient’s shoulder anatomy. “That allows us to simulate the placement of the implant and determine the bone preparation and every aspect of the instrumentation before entering the operating room,” Dr. Donohue says.

Shoulder replacement surgery is not minimally invasive, but both traditional and reverse shoulder replacements are muscle-sparing, meaning they cut through less muscle tissue than traditional surgery, which can mean a quicker recovery and improved outcome. Patients may be positioned sitting upright or semi-upright to allow better access to the shoulder. The surgeon makes an incision that’s often a few inches long—although the size varies, depending on the patient—on the front of the shoulder, then navigates the surgical instruments between the muscles to the joint, minimizing the need to cut tissue.

In addition to general anesthesia, a nerve block—an anesthetic used only on the surgical site—helps relieve surgical pain and reduces or eliminates the need for opioid medication after surgery. The nerve block is already working when the patient wakes up from the surgery, at which point pain may be managed with oral medications, a cold therapy machine (special equipment that uses cold to numb the area), and compression sleeves. “Nerve blocks allow us to use less general anesthesia, and they are extremely helpful in reducing the amount of initial—and overall—pain,” Dr. Donohue says.

While this varies, it’s important resume activities gradually, starting with light activities in the first few days, such as waist level activity, desk work, and light walks. Overhead reaching is not allowed until sufficient healing has occurred. Both types of shoulder surgery are typically followed by 12 weeks of physical therapy, Dr. Donohue says.

“There are different phases of therapy,” he says. The first is the motion phase, which involves stretching the shoulder to restore motion. That’s followed by strengthening exercises. “Usually, by three months, patients are reaching overhead,” he says. More strenuous activities take longer to get back to. “If you play golf, for instance, it's usually five to six months before you’ll be playing 18 holes again,” he says.

Dr. Donohue says that more than 90% of shoulder replacements done 10 years ago are still working well for patients today. “Implant design and technology continues to evolve so today’s implants may last even longer.”

Shoulder implants are made of the same materials as those used for hip and knee replacements, which are usually created with some combination of titanium (the part of the implant that interfaces with the bone); cobalt-chrome, a metal alloy; and high-molecular-weight polyethylene. Most are “in-growth” implants, meaning the bone grows into the implant, eliminating the need for cement. Implants still can eventually wear out over time, so a revision surgery is always possible.

But implant innovations enable the surgeon to tailor an implant to a patient, which can help the implants last longer. “Different companies offer software that enables the surgeon to virtually simulate implant placement in a patient’s shoulder,” Dr. Donohue says. “Some software can even predict post-operative range of motion, and at Yale, we can rapidly produce 3D printed models of the joint. which is a powerful tool for treating a patient with bone loss or deformity.”

One breakthrough is pyrocarbon, which was approved by the Food and Drug Administration (FDA) in 2023 to manufacture the humeral head. Pyrocarbon has properties that are more similar to bone than traditional implant materials that are made from metal. Because pyrocarbon may last longer, it is especially useful for younger patients.

Another breakthrough includes patient-specific implants that are custom made to precisely match a patient’s anatomy. “Patient-specific technologies were once reserved for patients with severe deformity or bone loss. Today, these technologies are being used for a wide range of patients,” says Dr. Donohue. “I see a future where patient-specific implants and associated technologies become the norm.”

Shoulder pain and mobility problems can interfere with daily life. There are good treatments available, like medications and physical therapy. If the pain is severe and does not improve with these methods, surgery can help.

“I would encourage patients with shoulder pain to explore their options,” Dr. Donohue says. He advises getting an X-ray to assess the cause of shoulder pain.

As far as treatment, “Some patients are willing to live, to some degree, with compromised function, while others will really start thinking about what that means in terms of the activities they enjoy. My goal is to empower people with the information they need to make their own choices.”