TRIQUETROLUNATE DISSOCIATION

by Lorenzo G. Walker, M.D.

Surgery of the Hand and Upper Extremity

Triquetrolunate (TL or LT) injuries and disorders are being diagnosed with increasing frequency, but there is not even agreement as to what to call this condition. Some authors use the term triquetro-lunate, others prefer luno-triquetral.

More severe forms of TL dissociation may progress to a palmarflexion instability pattern (VISI), but here is where much of the confusion arises, and there is controversy as to which specific ligaments are involved (Fig. 22-33) and what degree of ligamentous damage is necessary to cause VISI. Table 22-5 compares the various clinical and laboratory studies that have been done, and it is clear that there is no agreement. My interpretation of these conflicting studies leads me to believe that we do not truly know whether triquetrolunate (CID-VISI), triquetrohamate (CIND-VISI), or a combination of both is the major instability leading to VISI. It is important to make the distinction between these two, because the treatment requirements for these two entities are fundamentally different.

Clinical Diagnosis

Most of these patients relate a specific injury of the wrist, usually dorsiflexion, and the major complaint is pain on the ulnar aspect of the wrist. Some patients will describe a painful click. The most important physical finding is point tenderness directly over the triquetrolunate joint, and another helpful finding is a positive ballottement test as described by Reagan.

It is not always easy for me to be certain that a patient's symptoms are due to triquetrolunate instability. Well localized and consistent tenderness over the TL joint, a bone scan showing increased uptake in that area, transient relief following steroid injection of the ulno-carpal joint, and direct confirmation of ligament damage either by arthroscopy or at operation are the best diagnostic parameters. In such patients, I prefer an arthrodesis of the TL joint, using autogenous bone from the distal radius and with solid internal fixation using Shapiro (3M) staples or multiple buried K-wires.