The pain in Carol Driesen's left shoulder started out as the kind of garden variety arthritis ache that many people usually begin to notice sometime in their 50s. Driesen tried a variety of arthritis medications with little effect. Then came the day when she decided to do something more. "I was taking a class, sitting at a desk, not doing anything physical and still practically whimpering from the pain," Driesen said.

First, she tried arthroscopy, a minimally invasive procedure to smooth the roughened edges of bone within her left shoulder joint. Finding little relief from that procedure, she took the next step, a full joint replacement, in 2000. A year after that surgery, not only was there again little change in pain, but she also lost much of her shoulder's range of motion. Driesen gave up. "I just figured I had to make do with it."

Driesen did her best to make do. She is right-handed; after several years, however, she noticed that her increasing dependence on that right arm had a downside: The pain in that shoulder increased, too. Not wanting to push that shoulder beyond its limits, Driesen finally decided to risk another surgery. This time, she would make certain that she would choose the most experienced orthopaedic surgeon she could find and someone who specialized in shoulder replacement. "I really wanted to make sure that this time it would be done right," she said. Even at 76, she was still active, a busy woman who often baby-sat her toddler granddaughter. She was not willing to settle for pain reduction only; she wanted function, too.

After some considered looking, she found John Costouros, MD, at Stanford Hospital & Clinics. Costouros told her what she already suspected: Her only option was a surgery very different from her original. To restore her ability to move her shoulder, she needed a reverse shoulder replacement.

The anatomy of the shoulder presents a special challenge for repairs. The ball-shaped top of the humerus bone fits neatly into the glenoid, the curved space at the end of the scapula. A standard shoulder replacement puts a new cap on the humerus and a new lining on the curved wall on the glenoid. But the joint gains most of its mobility from a ring of muscles and tendons called the rotator cuff. If that cuff is torn beyond repair, the standard shoulder replacement will do little to restore the shoulder's function or to eliminate pain. 

Different thinking

With the reverse shoulder replacement, the humerus is transformed into the new base for the socket, capped with a socket-shaped top; the curve of the glenoid becomes the new ball, implanted with a rounded platform. The deltoid muscle then takes over for the rotator cuff and acts as the lever for the arm, becoming the prime mover of the shoulder joint.

Driesen's bone loss was so substantial and her rotator cuff so damaged that the reverse shoulder procedure was the only option. Costouros also would need to take part of her pelvic bone as a graft to reconstruct her glenoid so it would be stable enough to support the new implant.

It would be a complicated surgery, but Driesen had confidence in Costouros. The reverse shoulder procedure was performed in Europe for decades before it was approved for use in the United States, in 2004. Costouros did an additional fellowship in Switzerland with one of the field’s most prominent surgeons to gain additional experience with the reverse shoulder replacement and other innovative procedures. 

"I really had the opportunity to learn from everything they'd learned over the years in Europe," Costouros said. By the time Driesen came to see him at Stanford, he had completed more than 300 reverse shoulder surgeries. He had also become a well-known trainer of other surgeons throughout the country.

"I liked him very much," Driesen said. "He didn't push and he told me what I might expect. He was very confident and his confidence built mine."

Shoulder replacements are a relatively new procedure. The first widely used shoulder implant became available in the early 1950s and was based on designs for hip replacements. It was very much a one-size-fits-all, Costouros said, with little adaptability for differences in body size. "They didn't perform very well," he said. By the 1990s, the parts for shoulder replacements had become more modular, so surgeons could choose the proper size for each patient. 

Discovering New Options

The combined improvements, and the introduction of the reverse shoulder procedure, have made shoulder replacements the fastest growing segment of joint replacement types, Costouros said. "In the last 10 to 15 years, we've really seen an explosion in our understanding of the anatomy and biomechanics of the shoulder, better surgical techniques, and things that happen at the molecular level," he said. "Because of that, we've been able to design better implants and better implantation methods. Outcomes and longevity of shoulder implants today are far superior, enabling patients to obtain predictable pain relief and function that in past years was not possible"

In Driesen's shoulder, Costouros saw the kind of deterioration that has become well known to occur in older implants. "The prosthesis had loosened in the socket, and its plastic showed wear. It had all shifted and migrated due to the development of a rotator cuff tear." Without the surgery, Driesen would have lost more and more function, he said, and her pain would have increased. "This procedure really is a life-changing and dramatic intervention for patients,"he said.

In the future, Costouros said, such replacements may be outdated by cell-based therapies to modulate conditions like arthritis.

Driesen was hospitalized for just two days after her surgery. "I was progressing so quickly and I was off all pain medications after 10 days," she said. "I've had no pain since then." She began physical therapy, which she said hasn’t been painful either and continues now at two months following surgery. "It has increased my range of motion to the point where lying down I can lift my arm from down at my side to up over my head and hold my arm straight up pretty much indefinitely," she said.

Working with a physical therapist is very important, Costouros said, "because of the complexity of the shoulder, it can be predisposed to stiffness. It's important to work with a therapist throughout the different phases of recovery, which usually take three to four months."

Even though Driesen's recovery will continue as she builds back strength in her left arm, she is happy with the improvement. "It certainly has made me more comfortable and more able to do the things I want to do," she said.