DIAGNOSIS OF TEARS OF THE QUADRICEPS TENDON OF THE KNEE - VALUE OF SONOGRAPHY

OBJECTIVE. The purpose of the study was to evaluate the role of sonogr aphy in diagnosing traumatic tears of the quadriceps tendon. More spec ifically, it was intended to determine the value of sonography in diff erentiating complete from partial tears and thus in directing therapy. Knees of asymptomatic volunteers and patients' contralateral knees we re used as normal standards. SUBJECTS AND METHODS. Sonography was perf ormed in 29 patients with injuries of the quadriceps tendon in a 3-yea r period. As the control, 59 normal knees were examined: both knees of 15 healthy subjects and 29 contralateral knees of the injured patient s. In all cases, longitudinal and transverse sonograms were obtained. In five cases (four complete and one partial rupture), the sonographic diagnosis was confirmed surgically. Those remaining patients who had a partial tendon tear were treated conservatively. Follow-up sonograms were obtained in 10 cases (three treated with surgery and seven not) and showed integrity of the affected tendon. RESULTS. Among the 29 pat ients, sonograms showed a partial rupture (focal hypoechoic defect in the tendon) in eight and a complete rupture (complete disruption of th e tendon fibers) in four. In the remaining 17 cases, the tendon was in tact. The high sensitivity and specificity of sonography (100% or four of four in our sample) in the diagnosis of complete tears of the quad riceps tendon were confirmed by surgery. As only one partial tear was confirmed by surgery (the remaining seven were treated conservatively) , the sensitivity and specificity of sonography with respect to partia l tears could not be determined. CONCLUSION. Results of this study, al beit obtained from a limited sample, indicate that sonography offers a high degree of sensitivity and specificity in the evaluation of quadr iceps tendon rupture. This noninvasive and easily available imaging te chnique should be considered in the diagnostic workup and treatment pl anning of patients with suspected tears of the quadriceps tendon.