There are two types of hemiarthroplasty:

  • Stemmed hemiarthroplasty replaces the head of the humerus with a metal ball and stem, similar to the component used in a total shoulder replacement. Stemmed hemiarthroplasty is recommended when the humeral head is severely fractured or arthritic, but the socket is normal, or there is a large rotator cuff tear and a total shoulder replacement would likely fail over time
  • Resurfacing hemiarthroplasty involves replacing the joint surface of the humeral head with a cap-like prosthesis and no stem. Resurfacing hemiarthroplasty preserves bone and avoids the risks of component wear and loosening that may occur with total shoulder replacement over time.

Anatomy

The shoulder is a ball-and-socket joint made up of three bones: the humerus, scapula (shoulder blade) and clavicle (collarbone). The bones are covered with articular cartilage for smooth, pain-free motion of the joint. The muscles and tendons that surround the shoulder provide stability and support. All of these structures allow the shoulder to rotate through a greater range of motion than any other joint in the body.

Osteoarthritis and rheumatoid arthritis cause the surface layer of cartilage to wear away. Without this cushioning effect, the bones of the shoulder joint rub together. The shoulder can't move easily and becomes stiff, swollen and painful.

When is surgery recommended?

If you have shoulder pain that limits your everyday activities and all non-surgical methods of treatment have failed—including anti-inflammatory medications, cortisone injections and physical therapy—then you should consider shoulder replacement surgery.

A shoulder hemiarthroplasty can alleviate pain, improve motion, strength and function, and help you return to the activities you enjoy. However, the way a shoulder replacement will ultimately perform depends on a number of factors, including a patient's age, activity level, and overall health. It is important that each patient is thoroughly screened by an orthopedic surgeon to determine the most appropriate type of shoulder replacement.

What is the recovery time?

A careful, well-planned rehabilitation program is critical to the success of a partial shoulder replacement. Most patients wear a sling for three to four weeks. Gentle physical therapy begins immediately following surgery to regain range of motion and progresses to include exercises that strengthen the shoulder joint. Total rehabilitation time usually takes several months, but as with all surgical procedures, specific recovery time varies by patient and demand.