There’s a new option in the world of shoulder replacement implants. While stemless implants have been available in Europe for about ten years, that technology has finally made its way to the US. New implants take many years to get to market due to the testing required as part of the FDA testing process. Now that the implants are fully approved, they will soon be widely available.
In a typical shoulder replacement, the implant has a stem that extends down the center of the humerus (upper arm bone), which is hollow. That stem is adhered to the bone to help hold the replacement joint in place.
For many years, a cap or resurfacing device has been available for certain uses, but the caps were not well fixed to the bone. Thus, they could become loose over time and eventually need to be replaced with a traditional stemmed implant.
The new stemless implants do include fixation but without the stem reaching down the bone. The traditional stemmed implants will still be used for most shoulder replacements, but the stemless implants offer a new option for specific situations where they might offer an advantage over the traditional stemmed implant.
Potential need for future revisions
One of the biggest anticipated benefits of stemless implants is for younger patients who need a shoulder replacement because of the increased risk that they may need a revision surgery in the future. For patients under the age of 50 who undergo a shoulder replacement, it’s more likely that the implanted device won’t last their lifetime than in patients who are 65 or better at the time of the first replacement surgery.
Removing traditional stemmed implants can be a challenge and may result in fractures to the bone. The younger a patient is at the time of shoulder replacement, the more likely they will need a revision later, and stemless implants make revisions much easier if one is needed.
Past injury or fracture of the humerus
When patients have previously injured their humerus, it can create a deformity in the top of the bone and cause difficulty with placing a stemmed implant. Since stemless implants don’t reach as far into the humerus bone, it may be an option for patients with a prior fracture or other injury affecting the humerus.
Prior joint replacements
Some patients, for example patients with rheumatoid arthritis, may eventually need both a shoulder and elbow replacement. If both implants involve a stem, there is an area in the middle that is at high risk of fracture, so patients with a prior elbow replacement would be good candidates for a stemless shoulder replacement as well.
Is the new stemless implant right for you? It depends on your specific situation and the quality of your bone, as good bone quality is necessary to support the fixation of the stemless implant. Patients with significant osteoporosis or bone loss are not good candidates for these new implants and will generally be better served by a traditional stemmed implant. The stemless implant won’t replace traditional stemmed options, but rather it offers another option for use in specific situations. The surgical approach, recovery, and rehab are all similar to shoulder replacements using traditional stemmed implants.
If you need a shoulder replacement and fit any of the categories above, contact the Oklahoma Shoulder Center today to see if a stemless implant is right for you.