RESUMEN
Controversies exist about the value of ultrasound in diagnosing internal knee derangement. This study was conducted to evaluate the efficacy of ultrasonography in diagnosis of internal derangement of the knee by comparing the ultrasound results with the magnetic resonance imaging findings. Forty-four patients clinically presented with suggestive signs and symptoms of internal derangements of the knee joint were examined by both ultrasonography and MR imaging which were reported separately and their results were compared with each others. Ultrasound was found sensitive for detection of knee joint effusion, lipohemoarthrosis, and baker cyst where 100% of cases were diagnosed by US. The sensitivity of ultrasound for detection of meniscal tears was 83.87% with false negative results of 16.12%, while false positive results were encountered in only 4.54% of the examined patients. The sensitivity of ultrasound to detect complete ACL tear was 85.71%, however unsatisfactory results were obtained in detection of partial or chronic ACL tears. Also, fairly high sensitivity of US to detect MCL tear was seen in the current study; approaching 80%. Ultrasonography can be a useful modality in diagnosing internal derangement of the knee; when MR equipments are not available, with fairly high sensitivity in detection of meniscal tears, ACL and collateral ligaments tears