Procedures prior to Joint Replacement 

 

• Hip Arthorplasty 

 

• Knee Arthroplasty 

 

• Diagnostic Testing 

 

X-rays (radiographs) are the most common and widely available diagnostic imaging technique. Even if you just complain about a sprain in your wrist or ankle, your doctor will probably order radiographs to make sure no bone is broken. X-rays are always used for fractures and joint dislocations, and may also be recommended if your doctor suspects damage to a bone or joint from other conditions such as arthritis or osteonecrosis (bone cell death). Several X-rays from different angles may be needed. If you have a fracture in one limb, your doctor may want a comparison X-ray of your uninjured limb. Tell your doctor if you are pregnant before undergoing a CT scan. 

 

A CT scan (computed tomography) combines X-rays with computer technology to produce a more detailed, cross-sectional image of your body. It may be ordered if your doctor suspects a tumor or a frature that doesn't appear on X-rays The process is painless. You may need to drink or be injected with barium sulfate or a dye so that certain parts of your body can be seen more clearly. Tell your doctor if you are pregnant before undergoing a CT scan. 

 

Ultrasound is sometimes performed if your orthopedist suspects that you have a blockage in the blood vessels of your legs or arms. An ultrasound uses high-frequency sound waves that echo off the body. This creates a picture of the blood vessels. The Doppler audio system transmits the "swishing" sound of the blood flow. This is a noninvasive test that has no side effects. 

 

An MRI (magnetic resonance image) uses magnetic fields and a sophisticated computer to take high-resolution pictures of your bones and soft tissues, resulting in a cross-sectional image of your body. It can be used to help diagnose torn muscles, ligaments and cartilage, herniated disks, hip or pelvic problems and other conditions. Many patients are concerned that they should not get an MRI with a metal implant. You may still have an MRI done, however, you should let the technician or requesting doctor know so that they can request a metal artifact reducing sequence MRI (MARS MRI). 

 

Joint aspiration may be both a diagnostic test and a treatment option. In conditions such as bursitis, there is a fluid build-up that results in swelling and pressure. A similar fluid build-up around the joints can occur with injuries and arthritis. Aspiration, or removing the fluid through a syringe, can reduce swelling and relieve pressure. Analysis of the fluid may determine if the fluid result from an infection or an inflammatory response. 

 

As part of your examination, your orthopedist may order a variety of blood tests. Some conditions, such as rheumatoid arthritis or infection, may be identified by the presence of a specific substance in your blood. Usually a blood test is a simple matter that involves withdrawing a small amount of blood from your arm. If you or your doctor suspect a problem with your implant or you are experiencing a lot of unexplained pain, it may be a good idea to have your metal ion levels checked. Typically your surgeon will not advise getting this test done until you are at least one year post op. The metal ion test is usually outsourced to an outside lab such as quest diagnostics or labcorp. It has to be done using special metal-free tubes to avoid contamination and you will need to stop taking supplements two weeks prior to your metal ion test. There will be some variability between the lab centers used, so try to stay consistent with the lab you go to. More information on metal ion testing can be found at:

 

http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/ImplantsandProsthetics/MetalonMetalHipImplants/ucm331971.htm

 

Helpful links: 

http://orthoinfo.aaos.org/topic.cfm?topic=A00396 Inflammatory Arthritis of the Hip

http://orthoinfo.aaos.org/topic.cfm?topic=A00221 Knee Replacement Implants

http://orthoinfo.aaos.org/topic.cfm?topic=A00406 Rotator Cuff Tears and Treatment Options

http://orthoinfo.aaos.org/topic.cfm?topic=A00094 Shoulder Joint Replacement

http://orthoinfo.aaos.org/topic.cfm?topic=A00356 Activities after Hip Replacement

http://orthoinfo.aaos.org/topic.cfm?topic=A00377 Total Hip Replacement