RHA prostheses that replace your radial head are inserted directly into the remaining radius bone, and they sometimes loosen over time.

A radial head arthroplasty (RHA) is a procedure to replace the head of the radius bone — one of the two biggest bones in your arm that connect your wrist and elbow joints.

RHA treats elbow joints that have become unstable or worn down by arthritis, overuse, or injury and can’t be treated using other methods, such as corticosteroids.

But RHA joint replacements are not without risks.

Read on to learn more about what can cause an RHA prosthesis to become loose, how common loosening is, and how this issue is usually resolved.

The likelihood that an RHA prosthesis will loosen depends on several factors.

Radial head damage

A surgeon uses the remaining pieces of a damaged radial head to shape the RHA prosthesis and make it fit well.

If most or all of your radial head is gone, it’s more difficult for the surgeon to determine the right shape of the prosthesis to replace your radial head.

Prosthesis type

The risk of loosening can also depend on what type of RHA prosthesis was used.

There are several types of RHA prostheses:

  • press-fit
  • cemented
  • loose fit
  • expandable stem

The expandable stem prosthesis is considered the least likely to loosen. This is because the stem of the prosthesis is inserted directly and securely into the radius bone and may be expanded even deeper into the bone over time.

A very small 2023 study of six people who received a press-fit prosthesis noted that five of the six participants experienced loosening. Four of these people had noticeable pain and lost some movement in their elbow joint until the prosthesis was taken out.


How vigorously you use your elbow joint after the procedure has a major impact on the risk that the prosthesis will loosen.

Using your elbow joint for strenuous activities can put a lot more wear and tear on your elbow joint. Your prosthesis is more likely to loosen or fail if you frequently use your elbow to lift or throw or if you strain your arm.


The material used in the prosthesis doesn’t typically have a major effect on the risk of loosening.

But an older 2016 review article of RHA studies from 1940 to 2015 found that silicone prostheses were more likely to fail because of their inability to work well with the tissues and mechanics of the elbow joint.

Most other materials, such as titanium, appeared to have about the same success rate over time.

In a 2019 review of 34 articles, researchers closely examined the cases of 152 people whose RHA prostheses had failed.

About 30% of these people experienced loosening and needed surgery to fix or replace their prostheses an average of 34 months after surgery.

But a 2020 study of 30 people who underwent RHA found that only 1 person who received a press-fit prosthesis experienced any loosening around the shaft of the prosthesis. And a 2021 study of 114 RHA procedures found that 26% of the prostheses loosened over time.

The most common treatments for loose-fitting joints are revision, replacement, and removal.

Revision usually means that the surgeon has to open an incision to access your elbow joint again and change the prosthesis so it fits more comfortably in your joint. The surgeon might extend the stem of the prosthesis or align the head of the prosthesis to move more in line with the rest of the joint.

Replacement means that the surgeon uses a new or different prosthesis in the joint. For example, they might decide to replace a press-fit prosthesis with an expandable stem prosthesis because it’s generally less likely to loosen.

Removal means that the surgeon removes the prosthesis and does not replace it with a new one. Your surgeon may choose to do this if the prosthesis is causing you a lot of pain or keeping you from fully moving your elbow joint.

Some of the most common risks and side effects of RHA are:

  • loss of some ability to extend your elbow joint
  • lack of full stability in your elbow joint when performing daily tasks
  • pain when you move your elbow
  • pain or stiffness that doesn’t get any better or worsens after the procedure
  • redness, swelling, or infections in the area where the surgery was done
  • numbness or tingling around your elbow joint
  • new osteoarthritis in your elbow joint

RHA may not be enough to repair an elbow joint if there is damage to the surrounding ligaments or other bones. In this case, RHA should not be done unless these other damaged tissues are also repaired.

Having an unstable fracture can make it more likely that you’ll need follow-up surgery for a revision or repair. This means that the joint is more likely to dislocate even during normal activities because the whole joint has been disrupted by injury or overuse.

Additionally, you may not be a good candidate for RHA if you don’t have bone material strong enough to support the prosthesis or if you’re allergic to any of the materials in the prosthesis.

RHA is a common procedure used to treat an elbow joint that has become unstable or damaged by wear or injury.

Loosening of the prosthesis after RHA is fairly common and can often be treated successfully to reduce pain and increase range of motion.