Arthrography is done most commonly to identify abnormalities associated with the shoulder, wrist, hip, knee and ankle. Patients who undergo this procedure usually have complained of persistent, unexplained joint pain or discomfort. Arthrographic images may allow identification of problems with a joint’s function or indicate a need for a joint replacement.
No special preparation is necessary before arthrography. Food and fluid intake do not need to be restricted. It is very important that the nurse is made aware of you allergies, particularly if you are allergic to iodine.
A nurse or radiological technologist may ask you to change into a gown with no metal fasteners that can show up on the images. If necessary, you may also have to remove some of your jewellery if it will interfere with the procedure.
You will be positioned on an examination table. Above you will be a box-like structure containing the x-ray tube and fluoroscopic equipment that will send the radiographic images to a screen monitor either in the examining room or in a separate room for the radiologist. Underneath the examination table is a special drawer that holds film in a cassette tray for development of still images.
Other equipment necessary for performing arthrography include a variety of large needles, syringes, water-soluble and colorless contrast material, sterile sponges and towels, a container to hold the removed joint fluid, and a sterile adhesive bandage.
Joint fluid is removed and replaced with injected contrast material or air — sometimes both. A series of radiographs, sometimes called “arthrograms,” are obtained before the joint tissue absorbs the contrast material. Occasionally, the examiner will take additional x-rays as he or she pushes and pulls on your joint.
In the examination room, you are positioned on a table to examine the affected joint. Simple x-ray images of your joint are obtained to compare with the arthrograms.
Next, the skin around your joint is cleansed with antiseptic, and a local anaesthetic may be injected into the area around the joint. A needle with an aspiration syringe is then inserted into the joint space. The radiologist will use the syringe to drain the joint fluid, which may be sent to a laboratory for analysis. Next, the aspirating syringe is replaced with one containing contrast material. If the fluoroscopic examination shows correct needle placement, the contrast material and air are injected into the joint space. After the injection, the needle is removed and the site is rubbed with a sterile sponge and may be sealed with collodion to prevent air from escaping. You will be asked to move the affected joint to more evenly distribute the contrast material. Still images are then obtained with the joint in various positions.
The examination is usually completed within 45 to 60 minutes.
To many patients, the thought of having needles plunged into their joints seems particularly gruesome. But just as major dental work is done only after the administration of an anaesthetic to numb the involved area; your joint area may be numbed so you do not feel anything related to the arthrographic procedure. Initially, you may experience a slight pinprick and momentary burning as the anaesthesia is injected into the joint area. You may feel a fullness as the joint is filled and you may feel and hear gurgling when the joint is moved.
Most patients undergo arthrography because it has been recommended by their orthopaedic surgeon or primary care physician, also called the referring physician. The images are interpreted by a radiologist, though not necessarily the one who was present during your examination. The interpretation is subsequently forwarded to your orthopaedist or primary care physician. Depending on the interpretation, you and your physician will determine the next course of action, such as treatment for an abnormality, if necessary.