Whether you're younger than 65 or older than 75, age may not be a discernible factor in the success of shoulder replacement surgery, according to a Henry Ford Hospital study.

In a small prospective study of 365 patients, researchers made a surprising finding: While younger patients had better function and range of motion before , it was the older cohort that saw greater improvement from pre-operative levels after surgery. Younger patients also had a higher complication rate.

Researchers theorize that the older patients had greater improvement simply because they had worse before surgery.

The study is being presented at the American Academy of Orthopaedic Surgeons annual meeting in San Diego.

"Much like we saw with hip and knee replacements, we are seeing an increased trend in shoulder replacement surgery," says Kelechi Okoroha, M.D., a fifth-year resident in Henry Ford's Department of Orthopedic Surgery and the study's lead author. "Our study suggests that age is not have a noticeable factor on the final outcome of surgery. However, see more improvement in their shoulder function than what they had prior to surgery."

An estimated 53,000 people undergo each year due in large part to the "wear and tear" type of arthritis called osteoarthritis. People who have surgery experience an improved quality of life including less pain, improved motion and strength, and function.

Researchers at Henry Ford in Detroit analyzed data and shoulder function scores from two patient cohorts with osteoarthritis who had surgery: 262 patients under 65 and 103 older than 75. Patients older than 75 showed greater improvement in shoulder function scores after surgery.