Ever since the Stryker hip implant recall in 2012, thousands of patients have required a revision surgery. Elderly patients have been forced to undergo painful and invasive hip revision surgeries as a result of corrosion in the Stryker Rejuvenate and ABG II hip systems. Patients may require a hip revision surgery if they suffer from the destruction of bone or muscles, nerve damage or infections.
Those who have hip implants should aim to detect adverse tissue reaction and other negative reactions as soon as possible. Technology and sophisticated medical tests have been developed to assist patients in these early detection methods. Specifically, the Center for Metal-on-Metal Total Hip Replacement has created a test able to detect adverse tissue reaction in metal-on-metal hip implants.
The basic process of assessing adverse tissue reaction includes the following stages:
- A clinical assessment
- Completion of X-rays
- Analysis of a patient’s prior X-rays
- Measurement of cobalt, chromium and titanium ions in the bloodstream
- Determination of component positioning while standing
- Detection of Edge Loading in Vivo
Metal Ion Analysis in MoM Hip Devices
Thorough procedures are now in place to assist patients in the measurement of metal ions in the bloodstream. An expert will use a needle, syringe or tube that is not contaminated with metal ions (see here). He or she then withdraws a blood sample and stores it in a contamination-free plastic vessel. The Center also uses a sophisticated procedure called Inductively Coupled-Plasma Mass Spectroscopy (ICP-MS) to detect metal ions in the bloodstream. This procedure provides a very thorough and precise analysis of the number of metal ions in one’s bloodstream.
Evaluation of Edge Wear in Stryker Hip Implants
Another sophisticated test that is now used to assist patients in detecting adverse tissue reaction is the 3-D radiographic evaluation. This evaluation utilizes low radiation to assess wear and corrosion in a device while the patient stands. If the acetabular component is dislodged from the socket, then this test will reveal this defect. The physician can detect whether the acetabular component is in the proper place while the patient stands. Otherwise, the physician may have difficulty in thoroughly analyzing the acetabular component while the patient sits or walks.
The research and evaluation process also includes detection of movement that accelerates the wear of metal-on-metal hip implants. A physician uses 3-D CT reconstruction to understand how the components rub up against each other. At certain angles, hip implant components may rub up against each other with immense force. After the physician analyzes the patient’s risk for experiencing edge loading, he or she can determine whether the patient requires a hip revision surgery or simply needs to avoid certain activities. Certain activities, such as climbing stairs, may trigger the destruction, corrosion and wear of a Stryker hip implant.
Analyzing Test Results with MoM THR Clinical Evaluation Guidelines
After a physician conducts a clinical evaluation, analyzes symptoms and considers the patient’s X-rays, he or she will follow-up with the patient. Patients who have normal test results will require a follow-up after 12 months. Those who have mild symptoms of adverse tissue reaction will require follow-up in six months. Patients with severe and worsening symptoms may need to schedule a hip revision surgery.
The Use of Cross-Sectional Imaging Studies for Revision Surgeries
If a patient has abnormal test results, he or she may be a candidate for a hip revision surgery (look here for more discussion on Stryker revisions). The physician will create a report that combines the blood test, imaging studies, wear analysis and other specialized analysis to determine whether the patient is a candidate for the hip revision surgery. Also, a second orthopedic surgeon will provide his or her professional opinion about whether the surgery is required.
Using cross-sectional imaging studies (MRI) helps orthopedic surgeons determine the best way to proceed with the revision surgery in order to minimize tissue destruction. Soft tissue damage is one of the many risks associated with a hip revision surgery. Orthopedic surgeons also review the MRI report to decide how to reconstruct the hip and any other risks that the patient faces. He or she will need to determine why a Stryker component failed and the steps necessary to improve the functioning of the new hip implant.
Get the Help You Need
If you received a Stryker hip implant before 2012, you may require a revision surgery in the future. You can protect your future health and best interests by speaking with your physician about the functioning of your Stryker hip implant. A physician can use these tests and technology to determine whether you are at risk for requiring a revision surgery.