Midcarpal wrist arthrography for detection of tears of the scapholunate and lunotriquetral ligaments

Abstract

After preliminary scout films, the patient is placed in the supine position with the arm at the side and hand pronated. The midcarpal space is entered between the scaphoid and capitate bones, near the distal end of the scaphoid. This space is easily seen fluoroscopically and is optimally widened with the wrist prone in ulnar deviation (fig. 1A). A metallic marker is centered over the midpoint of the widened space, the skin is marked, and the patient is cautioned to maintain ulnar deviation until the contrast medium injection is made. After sterile skin preparation, a small amount of local anesthesia is administered and a 23-gauge needle is directed perpendicularly into the joint space. A preloaded syringe and venotube with 60% contrast medium is then attached to the needle. The scapholunate and lunotriquetraljoints are kept in view and watched carefully with continuous videotape recording as the injection is made . Usually 3 ml of contrast medium will satisfactorily fill the midcarpal joint spaces. Fluoroscopic monitoring should be continued until the joint spaces are filled (figs. 1B and 2). If monitoring is not continuous at this critical time, contrast medium may leak unobserved through a tear of the scapholunate or lunotriquetral ligament and quickly spread through the radiocarpal space, making a judgment impossible as to which interosseous ligament is disrupted (fig. 2). It is important to obtain standard radiographs as well, since with further manipulation of the wrist by the technologist in positioning, other ligarnentous tears may be revealed. If the midcarpal arthrograrn is normal, a radiocarpal joint injection should then follow, so as not to overlook the possibility of other radiocarpal joint disruption accounting for symptoms.