- Discussion:
- arthrography may be used in diagnosis of carpal instability because it is technically easy & is only minimally invasive;
- normally there should be no communication between the radiocarpal, mid-carpal, and distal radial-ulnar joints;
- it is noteworthy that in normal wrists there may be communications between different compartments & that these communications should not be assumed to be caused by trauma;
- communications may indicate age-related degenerative changes;
- patients in their twenties will be perforated 8% of the time;
- communications may occur in upto 27 % of patients less than 35 years, w/ TFCC tears being the most common;
- by age 50, more than half of patients will have at least one communction;
- false negative results:
- a complete tear may be masked by scarr tissue which has impeded the flow of the contrast material;
- Mid Carpal Joint:
- arthrogram of normal mid-carpal joint shows contrast medium between scaphoid, lunate, triquetrum;
- non dissociative carpal instability:
- capitolunate instability
- ulnar mid-carpal instability;
- Ligament Tears:
- triquetrolunate interosseous ligament;
- arthrography is most accurate for diagnosing this condition;
- triangular fibrocartilage;
- provides most useful information in younger patients, since degenerative changes are common in older patients;
- may diagnose central TFCC tears and peripheral TFCC avulsions;
- false positive result:
- normal the extension of dye, from the radiocarpal joint into the RU joint, is consistent w/ TFCC tear;
- note, however, tear of the ulnolunate ligament will also allow egress of dye between these spaces;
- ulnolunate ligament:
- this is a key ligament along w/ the TFC;
- on occassion, may avulse from its insertion on the lunate, and this injury will allow dye extension both into the distal RU joint and into the mid-carpal joint;
- scapholunate interosseous ligament;
- injection of contrast into the radio-scaphoid joint, should allow contrast to flow into the scapholunate interval if the ligament is torn;
- false negatives may occur due to redundancy of the scapho-lunate ligament which may allow the ligament to bunch up and obstruct the flow of contrast thru a ligament tear;
- needle is introduced distally at STT or ulnarly at triquetrohamate joint so as to avoid injured area and possible errors in interpretation associated with extravasation;
- dye is followed under the image intensifier to see where it flows;
- both scapholunate & lunotriquetral penetrations are suggestive of respective injuries;
- flow palmarly through the space of Poirier is indicative of this space having been injured in a PLD.
- Technique:
- it is important that PA and lateral radiographs be taken with proper technique;
- elbow is flexed in 90 deg w/ neutral rotation;
- lateral radiograph is taken w/ arm at side
- PA radiograph is taken w/ shoulder abducted;
- arthrograms that are made by injecting all three major joints (radio-carpal, mid-carpal, and distal radio-ulnar) w/ contrast medium are helpful and sometimes obligatory;
- contrast medium: non ionic contrast (such as Omnipaque 300)
- greater sensitivity is achieved by first injecting contrast medium into mid-carpal row;
- this allows diagnosis of tears of the scapholunate or lunotriquetral ligaments;
- radiocarpal joint is next injected;
- test is positive for TFCC perforation if contrast material leaks into the distal RU joint;
- injection into the RU joint:
- direct injection into the distal RU joint may show dye leakage into the radiocarpal joint;
- important that the flow of opaque material be followed in an image intensifier to find leaks and abnormal communications;
- digital fluoroscopy has been used advantageously for same purpose
Arthrography of the wrist. Assessment of the integrity of the ligaments in young asymptomatic adults.
Wrist pain: correlation of clinical and plain film findings with arthrographic results.
Arthrographic evaluation of the carpal triangular fibrocartilage complex.
Disruption of the ulnolunate ligament as a cause of chronic wrist pain.
The Triple Injection Wrist Arthrogram.
Arthrography of the wrist joint. An experimental study.
Arthrography of the contralateral, asymptomatic wrist in patients with unilateral wrist pain.