Which Has Better Results: Total Shoulder Arthroplasty or Hemiarthroplasty?

As with advanced hip and knee arthritis, joint replacement (arthroplasty) is an option for patients who have continued pain and limited mobility despite non-operative treatment. In the United States shoulder arthroplasty is the 3rd most common joint replacement behind knee and hip replacement. Similar to hip and knee replacement, shoulder replacement typically leads to improvement in quality of life, reduction of pain, and improved mobility.

The three options

The primary joint replacement options in glenohumeral arthritis include a resurfacing, hemiarthroplasty, or total shoulder arthroplasty.

In a resurfacing procedure either part or all of the humeral head (ball) is removed and replaced with a metal ball. The reported advantage of a resurfacing is preservation of bone.

In a hemiarthroplasty, the ball is resurfaced and a stem is also placed inside the humerus. As opposed to resurfacing, a hemiarthroplasty removes slightly more bone. However, compared to a resurfacing, restoration of alignment is more predictable.

In a total shoulder arthroplasty both the ball and socket are resurfaced. The humeral head is replaced with a metal ball and stem, and the socket is resurfaced with a high strength plastic.

The debate, and what the evidence shows

Proponents of a hemiarthroplasty or resurfacing have argued that the procedure is less invasive and avoids the potential for long-term failure of the socket. Proponents of a total shoulder arthroplasty argue that pain relief and function are more predictable when both sides of the joint are treated.

An article by Sandow et al. in the July 2013 issue of the Journal of Shoulder and Elbow Surgery adds to the literature demonstrating better outcomes with a total shoulder arthroplasty compared to a hemiarthroplasty in the treatment of glenohumeral arthritis. In this study, patients were randomized to receive a hemiarthroplasty or total shoulder arthroplasty and were followed for 10 years after surgery. At the 10-year point:

• No patients in the hemiarthroplasty group were pain free, compared to 42% of patients in the total shoulder group.
• 90% of the total shoulder arthroplasties remained in place, compared to only 69% in the hemiarthroplasty group.

Also, in a review of nearly 2,000 patients, Radnay et al. found that total shoulder arthroplasty led to better pain relief and range of motion compared to hemiarthroplasty. In this study 97% of patients with a total shoulder were satisfied compared to only 80% with a hemiarthroplasty.

The conclusion

Based on these studies, as well as several others in the literature, it is clear that a total shoulder arthroplasty leads to more predictable results compared to a hemiarthroplasty for the majority of patients with shoulder arthritis. There are certain scenarios in which a hemiarthroplasty or resurfacing may be considered. But for the vast majority of cases, a total shoulder arthroplasty will lead to more complete treatment of the arthritis and subsequent improvement in function and reduction in pain.