Here are key takeaways from an episode of Kentucky Health focusing on advances in shoulder replacement surgery. Host Dr. Wayne Tuckson welcomed Dr. Scott Kuiper, M.D., an orthopedic surgeon practicing with Louisville Orthopaedic Clinic.
Diagnosing Shoulder Problems: Strains, Injuries, and Arthritis
“The shoulder has to position our hand in space, so it’s extremely important that it functions properly in terms of being strong, being stable, and having good range of motion,” Kuiper says. It is the most mobile joint in the body, supported by a complex structure of muscles, tendons and ligaments that surround the bone and socket in the shoulder and allow it to lift and rotate the arm.
The deltoid muscle, Kuiper says, is the major muscle supporting the shoulder that powers it to lift the arm, while the rotator cuff is a smaller muscle-tendon structure that attaches to the top of the shoulder bone – the “ball” – and helps rotate, lift, and compress it for stability. The labrum is a ligament structure that surrounds the socket and helps to stabilize it as well.
Shoulder function can be limited due to injury and also by degenerative diseases such as arthritis. When patients first visit Kuiper complaining of shoulder pain or loss of mobility, he and his staff will do a detailed exam including radiographic imaging. Sometimes, the problem can be traced to inflammation, he says. The conditions tendinitis and bursitis cause swelling and pain in the soft tissue structures surrounding the shoulder.
“Other things that can happen occur within the bone itself,” Kuiper says. “You can have a bone lesion, something we can see on X-ray. Sometimes our patients have injuries as a part of the history where the shoulder is dislocated, maybe in a traumatic fall during a sporting event or a work injury. In those situations, the lining of the shoulder, called the capsule, and those ligaments can be stretched or torn.”
Arthritis is the degeneration of cartilage lining a joint, Kuiper says. Cartilage is “the white shiny surface at the end of the bone,” he explains. “It should glide like two pieces of ice, and it has no nerve endings, so there’s no pain when you move your joint. If that cartilage gets damaged, then that’s when people feel pain in their joint.”
Arthritis can occur in a young person after an injury if the articular cartilage is damaged. Others may have a genetic predisposition to early deterioration. But most people get arthritis as they age and the articular lining thins over time.
Two main types of arthritis are rheumatoid arthritis and osteoarthritis, Kuiper says. Rheumatoid arthritis is a chronic autoimmune disorder (when the immune system attacks normal tissue) that causes inflammation around joints and wears out the articular cartilage. “That’s a different type of arthritis as opposed to osteoarthritis, which is the wear and tear of aging over time,” he says.
Kuiper says that persons with rheumatoid arthritis are treated first with medication prescribed by rheumatologists to try and suppress the chronic inflammation. Likewise, he says that non-operative treatments are recommended first for patients with osteoarthritis, such as medications and/or physical therapy.
“If someone has failed these conservative modalities, we then start to discuss surgical management,” Kuiper says. He will consider the patient’s age, work history, and history of injuries while consulting about surgical options. Over the past couple of decades, he says, orthopedic physicians have developed new technologies and procedures for shoulder repair or replacement that can help patients recover most or all of their abilities.
How Shoulder Replacement Surgery Works
Kuiper explains what is called a “total shoulder” surgery for patients who have arthritis or have suffered an injury. He makes an incision at the top of the shoulder bone and puts a stem in there, and then replaces the “ball” which contains arthritic cartilage with a metal ball. He then smoothes out the socket on the side opposite the ball and inserts a plastic piece to fit the ball. The arthritic cartilage is removed completely.
“Now, if someone has a rotator cuff tear, though, this type of surgery doesn’t work, or at least not for a long period of time, because the biomechanics are not proper,” he says. “The ball will actually elevate up and ride on the socket improperly and wear it out more quickly, and actually create pain on the upper bone.”
In that case, Kuiper will perform a “reverse shoulder” procedure. Developed in the 2000s, the procedure involves securing the new metal ball on the socket side of the shoulder, and adding a socket to the top of the shoulder bone. “They come together and rotate, but now because of the biomechanics, it won’t come up and rub the bone above. And the big muscle, the deltoid, can now lift the arm if the patient doesn’t have a rotator cuff to lift the arm. So it solves two problems at once – it solves the rotator cuff problem and it also solves the arthritis.”
When operating, Kuiper can’t see the entire socket as it exists in place, but newly developed 3-D CT scan technology enables him to get an image that he can put into a computer and then plan out the surgery beforehand according to the specifications that are generated.
This new approach is extremely beneficial because the CT scan data can be adjusted for a patient’s size and specific deformity. “We want to try to establish the best biomechanically functioning shoulder possible,” Kuiper says.
According to Kuiper, there are around 55,000 to 60,000 total shoulders done in a year in the U.S. That’s compared with around 900,000 hip or knee replacements. When Kuiper began practicing, shoulder replacements usually required around a week in the hospital, but now he says patients usually stay only overnight for observation, and start rehab quickly.
Shoulder replacement surgery requires opening up a large area in the upper arm. Kuiper and his team take many precautions prior to surgery to reduce the chance of infection, including preoperative antibiotics, wearing PPE (personal protective equipment), specialized cleaning of the patient’s skin, and even placing a thin tape covering up the skin.
Advances in surgery mean that people can get shoulder replacements earlier in life than in the past. “I do a lot of rotator cuff repairs,” Kuiper says, “but for some people, their rotator cuff is un-repairable and it’s already at a young age. They might have hurt it when they were 40, and now they’re 50, and they have tremendous pain and they can’t lift their arm. And instead of making them wait until they’re 75 to do their surgery, they’re wanting to have this technology so that they can function better in their 50s and 60s.”
Shoulder replacement surgery can be done again on a patient if needed. “We expect that some people will need revision surgery over time,” Kuiper says, “and that’s been taken into account with this particular prosthesis called a platform stem. And a platform stem means that the part that goes into the arm bone can be used whether it’s a total shoulder or a reverse total.”
Some patients will have a total shoulder first using the platform stem and then require a reverse shoulder later when their rotator cuff is torn beyond repair. The platform stem enables the surgeon to remove the ball and socket from the original procedure and reverse them using the same stem that was inserted years before.
Kuiper will work with his patients to develop a physical therapy program that gets them back to full shoulder function as soon as possible, starting with range of motion exercises and then moving on to stretching and strengthening. He also says that exercising and moving the shoulder prior to surgery as part of a general fitness routine is “like money in the bank – it’s going to help you whether you end up having surgery or not.”