The value of sonography with micro convex probes in diagnosing meniscal tears compared with arthroscopy.

OBJECTIVE

Meniscal tears are common in knee injuries. Sonography has been used in the knee to evaluate meniscal tears. Linear probes with high resolution have been used, and the overall accuracy of sonography has been more than 70% in many studies. In this study, we used a 6.5-MHz micro convex probe to evaluate meniscal tears, and the results were compared with arthroscopic findings.

METHODS

Four hundred six knee joints with knee pain and a clinical indication for arthroscopy were examined from the popliteal fossa with the 6.5-MHz micro convex probe. Those patients with positive sonographic findings who had an arthroscopic examination (100 patients) were included in our study, and the results were compared. The results were statistically analyzed by the Fisher exact test.

RESULTS

One hundred knees with sonographic examinations underwent arthroscopic evaluation. Three age groups were included in the study (20-30, 30-40, and >40 years). Comparison of the results between the two methods showed sensitivity of 100% and specificity of 95% for sonography in detecting meniscal tears. The positive predictive value for the medial meniscus was 95%, and the negative predictive value was 100%; these values for the lateral meniscus were 93% and 100%, respectively.

CONCLUSIONS

Meniscal tears are common in all age groups. The use of sonography allows rapid, low-cost, and noninvasive exploration of meniscal tears as a first-line diagnostic method. We recommend high-resolution micro convex probes, which better fit the anatomic concavity of the popliteal fossa, as efficient investigation tools.