Shoulder replacement surgery is less common than hip and knee replacements, for a very logical reason: those lower joints bear our weight, which puts more wear and tear on them.
But while many people don’t know shoulder replacement surgery exists, it’s the third most common kind of joint replacement.
The workhorse shoulder
Shoulder joints get a continual workout throughout our lives.
We use them to cook, drive, lift, shake hands, play piano, catch a ball. This ball-and-socket joint has the greatest range of motion in the human body.
That range of motion depends on the smooth cartilage at the end of the humerus — the “ball” at the end of the upper arm bone — where it meets the socket, which is a cup in the shoulder blade called the glenoid cavity.
Over time, though, the cartilage can degenerate and develop holes, becoming less smooth overall, explains Dr. Ranjan Gupta, UCI Health orthopedic surgeon who specializes in shoulder, elbow and hand surgery.
The result is pain, especially if the wear becomes so severe that bone rubs directly against bone. And although pain relievers and other medications can help for a while, for people with severe, ongoing pain, the only real fix for the problem is joint replacement.
Finding the right surgeon
The very thing that gives the shoulder its amazing range of motion also makes replacing it more complicated than the equivalent surgery for a hip or knee: Shoulder movement depends more on muscles and tendons than other major joints.
A network of muscles, tendons and nerves runs through and over the joint, and these tissues must be moved aside with great care during surgery to get to the bones, Gupta says.
The success of the surgery depends as much on doing that part skillfully as the bone replacement itself — and that means lots of ongoing practice with the procedure.
“You want a doctor who does at least 20 of these surgeries a year,” he says. “That’s the magic number.”
Shoulder replacement recovery time
In a typical, anatomic shoulder replacement, the surgeon uses a high-density polymer cup to line the glenoid, Gupta says, while the top of the humerus, the “ball” in the ball and socket, is replaced with metal.
Patients typically spend a few days in the hospital and six weeks in a sling while the soft tissues heal.
One of the first things they notice, he said, is the sudden relief from pain that had been a constant presence in their lives. No physical therapy is necessary in most cases.
Not just an older person's surgery
As expected, many of Gupta’s patients are older people with osteoarthritis, which results from the deterioration of the cartilage that provides the crucial “smooth, gliding surface.” But many patients are middle aged.
“One of my patients was a 47-year-old dentist,” he says. “He had long-standing left shoulder pain, and X-rays showed he had complete bone on bone. Even though he was only 47, he couldn’t hold the instruments he needed to do his job.”
Some surgeries are even performed on young people, especially after sports-related injuries.
Two types of shoulder replacement
- Anatomic replacement. The conventional, anatomic replacement is one of two main kinds of joint replacements, Gupta says. It is used when the rotator cuff is robust enough to do its job.
- Reverse replacement. A reverse replacement is performed for people with large tears in the rotator cuff who have a type of arthritis called cuff tear arthropathy.
The rotator cuff is a group of muscles and tendons that connect the humerus to the shoulder blade, or scapula. The muscles give the shoulder its ability to rotate; the tendons provide stability for the joint. Patients with cuff tear arthropathy get little if any relief from the typical shoulder replacement because movement still relies on the damaged muscles and tendons.
In reverse shoulder replacement, the socket is placed at the end of the humerus, and the ball is placed in the glenoid, Gupta says. The switch allows the deltoid muscle along the top of the shoulder to provide the movement, reducing pain.
Making your shoulder replacement last
A shoulder replacement typically lasts 10 to 20 years, and Gupta says it is so successful that in patients older than 65, he has only had to repeat the surgery two times.
Young people, especially teenage athletes, are more likely to need second or third surgeries, he said, simply because they often don’t listen to his post-surgical advice and think they can go back to the extreme sports that injured them in the first place.
“It’s like tires on a car,” Gupta says. “The tires might be rated for 20,000 miles. You can drive them all in one year or you can drive just a couple of thousand miles over 10 years. It depends on what you do with it.”