Problems with Stryker v40 Femoral Head Hip Implant
What is a Stryker Hip v40 Head?
Almost every hip replacement surgery utilizes the following parts:
- Cup liner
- Femoral head
- Femoral stem
The cup, with the cup liner inside of it, is inserted into the socket in the pelvic bone. The femoral stem ends in a tapered neck that is inserted into the femoral head, which acts like a ball to rest in the hip ball-and-socket joint. Femoral heads can be ceramic or metal. The stem portion of the femoral stem is inserted into the femur.
All of these parts tend to be manufactured by the same company and implanted as a set.
Stryker is a leader in the worldwide market of hip replacement products. The Stryker v40 femoral head is causing problems for thousands of hip implant recipients nationwide.
Metal vs. Ceramic
Femoral heads can be made of either metal or ceramic. Companies like Stryker promoted the benefits of metal heads, which included increased range of motion, improved joint stability, decreased chance of dislocation, and reduced wear. Such benefits are appealing to almost all patients, but especially for younger or more active patients.
Corrosion, or the gradual breaking down of a metal, happens on many metal hip implants and is not necessarily a sign of poor design. However, if corrosion is so severe that it causes metallic particles and ions to flake off like debris and infect the hip joint, this can cause medical complications such as:
- Metal poisoning
- Loss of function
- Premature failures
- Revision surgeries
These problems are not likely with ceramic femoral heads. Metal heads incur ten times the amount of wear as ceramic heads.
Problems with Stryker Hip v40 Heads
The Stryker v40 femoral heads are metal, made from cobalt chromium. The tapered neck of the v40 femoral stem, however, is made from weak titanium. Connecting dissimilar metals often results in fretting corrosion, or the breakdown of metals caused by the rubbing action of two surfaces.
Because the Stryker v40 hip implant relies on a femoral head and femoral stem made of two different metals, fretting corrosion has occurred and resulted in metal poisoning and other medical complications. The metal poisoning can result in necrotic tissue that may have to be removed by revision surgery or could possibly cause a catastrophic separation of the femoral head from the cup in the pelvic socket.
Testing for Metal Poisoning
Many patients with Stryker v40 hip implants may not be experiencing any symptoms yet. However, it’s important to catch the medical problems resulting from the v40 femoral heads early in order to minimize damage to soft tissue, muscles, and bones.
A simple blood test can show your cobalt and chromium levels. Some patients suffering from the ill effects of their hip implants have had cobalt levels 47 times higher than normal and chromium levels 10 times higher than normal. Your doctor should be able to tell you if your cobalt and chromium levels are within the normal range. If not, you may have to undergo revision surgery to replace your v40 head and remove any necrotic (dead) tissue around the hip joint that may lead to infection.