Background: Meniscal lesions are the commonest lesions in the knee, and usually caused by athletic activities. Meniscal lesions diagnosis may need costly imaging modalities like magnetic resonance imaging [MRI]. However, MRI is not available in all medical facilities, especially peripheral and rural continents. Thus, there is a need for a readily available imaging tool. Knee ultrasound may be used as diagnostic modality as it is devoid of economic burden of MRI.
Aim of the work: The current work aimed to estimate the diagnostic accuracy of knee ultrasound and to correlate it with the results of MRI for diagnosis of knee meniscal lesions.
Patients and methods: Fourty patients with acute or chronic knee pain, swelling or movement restrictions were included. All were assessed by referral physician and submitted to knee ultrasound and MRI. Then results of ultrasound were correlated with that of MRI and diagnostic accuracy measures of ultrasound were calculated [sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV] and overall accuracy].
Result: Out of included patients, 28 were males. Their mean age was 36.7 ± 14.4 years [ranged from 15 to 60 years]. The ultrasound detected meniscal tear in 90%, degeneration in 47.5%, Para-meniscal cyst in 25% and discoid meniscus in 40%. The MRI detected meniscal tear in 80%, degeneration in 65%, para-meniscal cyst in 25% and discoid meniscus in 37.5%. For meniscal tear, the ultrasound had 83.3% sensitivity, 50.0% specificity, 93.7% PPV, 25.0% NPV and overall accuracy of 80.0%. Otherwise, the overall accuracy was 75.0% for degenerative changes and 95.0% for para meniscal cyst. Finally, it was 67.5% for discoid meniscus.
Conclusion: Ultrasound has shown reasonable diagnostic accuracy in detecting meniscal lesions. It could be used as a screening tool to prevent unnecessary and costly MRI.