Newswise — A few months ago, 63-year old Leona Carter could no longer use her right arm. She couldn't raise it, brush her teeth or get dressed.

The constant pain in her right shoulder was due to a massive and irreparable rotator cuff tear, along with severe arthritis. Her shoulder joint had worn out and the rotator cuff tendons in that shoulder were torn beyond repair. She put up with the pain as long as she could, but it eventually became unbearable.

A standard shoulder replacement, a decades old treatment for severe shoulder arthritis, would likely not have worked for her due to her deficient rotator cuff. However, a recently developed " and radically different " prosthesis, called a reverse total shoulder, offered the best chance of decreasing her pain and improving shoulder function.

"A normal shoulder is a ball-and-saucer joint, with its stability and motion governed to a large extent by the surrounding rotator cuff musculature," said Dr. Omer Ilhai, an orthopedic surgeon at The Methodist Hospital in Houston. "In arthritis, the smooth cartilage overlying and cushioning the surface of the bones is worn away, leaving rough, exposed bone surfaces to rub against each other. This bone-on-bone contact is very painful and usually associated with joint stiffness."

The reverse total shoulder takes a completely different approach to this condition, Ilahi said. In that procedure, the worn out saucer is actually replaced by a metal ball, whereas the worn out ball portion of the arthritic shoulder is replaced with a device that contains a large plastic cup. It turns out that replacing the saucer with a ball and the ball with a cup obviates the need for an intact rotator cuff to provide stability or motion.

Carter's shoulder pain decreased significantly and her function significantly improved.

"I'm just happy I can do my housework, feed myself, and do all the things I used to be able to do when my shoulder was healthy," Carter said. "The pain is gone and I can finally start enjoying life again."