Less bone is removed with new implant, potentially reducing pain after shoulder replacement surgery.

Story by: Erica Coghill on September 27, 2018

The U.S. Food and Drug Administration (FDA) recently approved a new less invasive implant for shoulder replacement that requires less healthy bone removal to anchor the new joint in place.

By removing less bone, patients potentially may have less pain while recovering and better range of motion than with conventional shoulder replacements.

Norton Orthopedic Institute surgeon Ryan J. Krupp, M.D., was a major contributor to a study of the Sidus Stem-Free Shoulder System from Zimmer Biomet implant. The study showed the implant worked just as well as a traditional implant, while preserving more bone.

Most patients in the study experienced significant improvement in their pain, better range of motion and strength, and a dramatic increase in their overall quality of life.

The recent FDA approval came in large part due to Dr. Krupp’s research.

Less postoperative shoulder pain and more range of motion

What makes the new implant special is that, unlike a traditional implant, it doesn’t require insertion of a long prosthetic shaft into the humerus bone — the long bone connecting the shoulder to the elbow.

Instead, the new, stemless implant connects to the humerus with a smaller anchor, resulting in less bone loss. Its anchoring mechanism consists of four short, fin-like prongs with a unique geometric design that keeps it in place.

“The stemless implant allows us to save more of the patient’s native bone, which is important for a number of reasons, especially given the fact that patients are living longer and more active lives today,” Dr. Krupp said.

Removing less bone can lead to less pain following shoulder replacement. Preserving bone also means a stronger foundation to support the implant.

“In addition, if the patient should ever need revision surgery in the future, we have more bone to work with and the implant will be easier to remove,” Dr. Krupp said.

Candidates need to have strong bones

Total shoulder replacement can eliminate pain for people with shoulder arthritis.

“The goal of a joint replacement is to replace with new, smooth surfaces those areas that have thin or no cartilage, which are often rough and misshapen and have bone erosion due to bone-on-bone grinding,” Dr. Krupp said.

The stemless shoulder implant isn’t for everyone looking for shoulder replacement surgery. Candidates must have good bone quality to support the implant.

“If their bone is too weak for the stemless implant, we would use a traditional stemmed implant,” Dr. Krupp said.

An X-ray or computed tomography (CT) scan can help doctors assess who would be a good candidate for the stemless implant.