I’m going to have my left shoulder joint replaced because of severe arthritis. The doctor told me that he might only replace half the joint. What is this decision based on?

Replacing the entire shoulder joint is called a total shoulder arthroplasty (TSA). Removing only one-half of the joint is a hemiarthroplasty.

The decision to replace part or all of a joint is made when the doctor looks inside the joint and sees the damage. A study at the Cleveland Clinic Foundation reports that a patient with decreased outward rotational motion will do better with a TSA. Likewise, severe bone damage and thinning requires a TSA.

Patients with a stable joint that doesn’t dislocate do well with a hemiarthroplasty.