POSTEROLATERAL ROTATORY INSTABILITY OF THE ELBOW - USEFULNESS OF MR-IMAGING IN DIAGNOSIS

PURPOSE: To evaluate the efficacy of magnetic resonance (MR) imaging i n the assessment of the normal and abnormal ulnar band of the lateral collateral ligament for diagnosis of posterolateral rotatory instabili ty. MATERIALS AND METHODS: In nine symptomatic patients and nine asymp tomatic subjects, MR imaging was performed with three-dimensional grad ient-recalled and fast spin-echo sequences. The nine patients had clin ical symptoms suggestive of subtle elbow instability. RESULTS: The com ponents of the lateral collateral ligament were identified; tears of t he ulnar band were noted in all symptomatic patients. The anterior fib ers of the lateral collateral ligament, including the annular ligament , were intact. All symptomatic patients subsequently underwent surgica l exploration and reconstruction. Positive clinical findings were demo nstrated at examination performed while the patients were under anesth esia. All tears of the ulnar band were confirmed. CONCLUSION With use of appropriate pulse sequences, MR imaging is an effective tool in the preoperative, noninvasive diagnosis of posterolateral rotatory instab ility.