Pseudotumors from Metal Hip Replacements
What is a Pseudotumor?
A pseudotumor is a large, solid, or semi-liquid mass of soft tissue growth inside the body, usually around the hip joint.
It’s a complication associated with metal on metal (MoM) hip replacements. Typically, pseudotumors form as a negative reaction to metal debris.
When the metal ball and metal cup of the hip implant rub together, this results in enough friction to shed these cobalt and chrome particles into the blood stream, muscle, and tissue.
The main symptoms of a pseudotumor are pain, swelling, and clicking at the hip site. Pseudotumor formation has been associated with high blood levels of cobalt and/or chromium. These lesions or masses are not malignant, so they should not be confused with cancerous tumors. However, they can pose serious health problems.
Causes of Pseudotumors in Metal on Metal Hip Patients
There are several theories as to what causes pseudotumors to form in people with metal on metal hip implants, including:
- Worn particles coming off of the device.
- An increase in metal ion levels in the blood; caused by debris given off of the replacement device
Symptoms of Pseudotumors
Many people with pseudotumors will have NO symptoms at all. However, for those who DO have symptoms, they may not show up until many years after the hip replacement operation. Those symptoms can include:
- Pain around the hip or groin areas
- Swelling, including around the foot or ankle
- Clicking sound in the hip
- Hip joint dislocating
- Decreased range of motion
Diagnosis of Pseudotumors
In many cases, pseudotumors will not show up on X-Rays. Consequently, if your doctor suspects you have a pseudotumor, he or she may order a combination of these diagnostic tools in addition to X-Rays:
- CT scan
- Blood test
- Aspiration: A needle is used to drain fluid from the joint to rule out infection.