Arthrogram

Author: A/Prof Howard Galloway*

What is an arthrogram?

An arthrogram is an image of the inside of the joint obtained by arthrography. This is a procedure carried out by inserting a needle into a joint and injecting contrast medium into the joint cavity using imaging to guide the needle into its correct anatomical position. Guidance may be obtained using fluoroscopy, CT or ultrasound depending on the joint to be examined and the radiologist carrying out the procedure.

An arthrogram image shows structures within the joint cavity; for example, ligaments, cartilage and menisci, as well as the synovial lining of the joint capsule itself. It is usually followed by more detailed scanning of the joint using CT or MRI cross-sectional imaging in multiple anatomical plains. The type of contrast injected will depend on the type of imaging used for post-procedure detailed scanning: iodine-containing contrast and/or air for CT, and gadolinium with saline for MRI.

Limited arthrography is used to confirm correct needle placement within a joint cavity before injecting medication (e.g. steroids) and/or an anaesthetic as part of the diagnostic and therapeutic management of joint pain.

What are the generally accepted indicators for an arthrogram?

An arthrogram is indicated in the following clinical situations:

• Persisting joint symptoms in the presence of normal or equivocal previous non-arthrographic imaging using MRI or CT (e.g. rotator cuff tears).
• As the initial study for assessing subtle internal joint disease in deep large joints (e.g. hip and shoulder), particularly if using low-field strength (e.g. 1 to 1.5 Tesla) MRI or older technology.
• Preoperatively where more detail of the articular cartilage (e.g. osteochondral injuries and loose bodies), peri-articular tendons (e.g. rotator cuff), labrum or synovium is required.
• To confirm needle placement in the joint before therapeutic injections.
• Very often the examining radiologist may decide in discussion with the patient whether arthrography is required or whether a non-arthrographic imaging study will suffice.

There are many other situations in which scans after arthrography may be helpful, and it is often prudent to discuss the clinical problem with the radiologist to obtain advice on the most effective study for the patient’s individual situation.

What are the prerequisites for having an arthrogram done?

Generally, the patient should have had at least a previous plain X-ray of the joint and often an ultrasound, CT scan or MRI. These should be available to the radiologist for assessment before arthrography.

Arthrography (like any test) should only be carried out when the additional information obtained has the potential to alter the treatment or provide additional prognostic information when compared with a non-arthrographic or alternate study (e.g. ultrasound for rotator cuff tear).

What are the absolute contraindications for an arthrogram?

• Infection in or overlying the joint
• See also contraindications for MRI

What are the relative contraindications for an arthrogram?

Reflex sympathetic dystrophy: Any procedure or minor injury may reactivate or aggravate the symptoms. The Reflex Sympathetic Dystrophy Syndrome Association guidelines recommend the avoidance of all types of even minor procedures on the affected limb.

Avascular necrosis of bones adjacent to the affected joint: Anecdotal reports suggest that arthrography aggravates the pain of avascular necrosis.

Anticoagulation: There is no evidence to suggest that arthrography is contraindicated for patients on anticoagulation within the normal therapeutic range. However, the risk of intra-articular or periarticular bleeding in deep joints; for example, the hip, is increased in patients on anticoagulants. This is can be minimised with the use of experienced operator technique and small needles.

What are the adverse effects of an arthrogram?

Arthrography is a very safe procedure and complications are unusual.

The most serious complication is an infection of the joint. This is usually caused by organisms from the patient’s skin being transferred into the joint and for this reason the procedure should not be carried out if there is broken or infected skin overlying the joint.

The risk of infection is not precisely known, but the best available information suggests that it is in the order of 1 in 40,000.

Occasionally, people may be allergic to the contrast medium that is injected and this most commonly results in a rash, but may be more serious (see InsideRadiology: Complications of ICCM). The risk of minor reaction (e.g. hives) has been reported at 1:2000. More serious reactions appear to be very rare.

A transient synovitis can occur with the use of iodine-containing contrast medium. For example, an increase in shoulder pain may be noted lasting 24–48 hours after an arthrogram of the shoulder. It is not associated with other systemic symptoms and settles spontaneously.

Complications of the MRI contrast medium (gadolinium chelate) have not been reported, probably because of the very small amounts used in arthrography.

Is there any specific post procedural care required following an arthrogram?

Increasing joint pain not settling in 24–48 hours especially when associated with systemic symptoms, such as fever, raise the possibility of joint infection (septic arthritis). Patients need to be clinically assessed urgently, and they may require possible joint aspiration, surgical lavage and antibiotic therapy.

Patients on anticoagulants who develop increasing joint pain may have a haemarthrosis. Although symptoms may resolve with rest, aspiration of the haemarthrosis may be required.

Are there alternative imaging tests, interventions or surgical procedures to an arthrogram?

Direct visualization of the intrinsic structures of the joint by arthroscopy carried out by an orthopaedic surgeon is the most common alternative test.

*The author has no conflict of interest with this topic.

Page last modified on 20/10/2017.