BIRMINGHAM HIP◊ Resurfacing System: Important MRI Safety Information
Magnetic Resonance Imaging (MRI) scans are a commonly used diagnostic tool for a variety health related issue. Overseen by a radiologist, these scans use magnetic fields and pulses of radio wave energy to create images of organs and structures inside the body.
Because of the technology used in MRI scanning, some artificial implants, like the BIRMINGHAM HIP Resurfacing System, can affect the imaging quality or negatively impact the scanning due to their use of metallic components.
Below is the information your radiologist will need to ensure the appropriate scanning protocol is used based on non-clinical testing conducted by Smith & Nephew.
MRI SAFETY INFORMATION
Smith & Nephew, Inc. BIRMINGHAM HIP Resurfacing (BHR) System implants are manufactured from a non-ferromagnetic material, cobalt-chromium-molybdenum alloy. Smith & Nephew has performed non-clinical Magnetic Resonance Imaging (MRI) studies on BHR implants which are determined to be MR Conditional in accordance to ASTM F2503-08, Standard Practice for Marking Devices and Other Items for Safety in the Magnetic Resonance Environment. MR Conditional refers to an item that has been demonstrated to pose no known hazards in a specified MR environment with specified conditions of use.
Non-clinical testing has demonstrated that the BHR System is MR Conditional. A patient with this device can be safely scanned in an MR system meeting the following conditions:
- Static magnetic field of 1.5 and 3.0 Tesla only
- Maximum spatial gradient magnetic field of 3,000 gauss/cm (30 T/m) or less
- Maximum MR system reported, whole body averaged specific absorption rate (SAR) of 2 W/kg (Normal Operating Mode)
- Cylindrical Quadrature transmit coils only
Under the scan conditions defined above, the BHR System is expected to produce a maximum temperature rise of 7.1° C after 15 minutes of continuous scanning.
In non-clinical testing, the image artifact caused by the device extended up to 10.2 cm from the BHR system when imaged with a gradient pulse sequence, and up to 7.6 cm from the device when imaged with a spin echo pulse sequence and a 3 Tesla MRI system.
There are potential risks with hip resurfacing surgery such as fracture, infection, loosening, dislocation and wear that may result in the need for additional surgery. The results and physical activities of this patient may not be representative of the results and physical activities that you may experience following surgery. Females of child-bearing age should not have the BHR device. It is unknown whether metal ions released by the device could harm an unborn child. Do not perform high impact activities such as running and jumping during the first post operative year while the bone is healing. Early device failure, breakage or loosening may occur if you do not follow your surgeon's limitations on activity level. Early failure can happen if you do not guard your hip joint from overloading due to activity level, failure to control body weight, or accidents such as falls. Hip resurfacing surgery is intended to relieve hip pain and improve hip function. Talk to your doctor to determine what treatment may be best for you.
The information listed on this site is for informational and educational purposes and is not meant as medical advice. Every patient's case is unique and each patient should follow his or her doctor's specific instructions. Please discuss nutrition, medication and treatment options with your doctor to make sure you are getting the proper care for your particular situation.