Aim: to clarify the reliability of two clinical meniscal tests, McMurray's and Apley's and the MRI imaging, in order to establish how to reduce unjustified arthroscopies.
Methods: 102 patients were selected out of 160. All patients were submitted to a triple clinical examination (by a young surgeon and two skilled surgeons), MRI and an arthroscopic procedure. The investigated clinical tests were McMurray's and Apley's test. The positivity or negativity of the tests and MRI were compared to arthroscopic findings. Arthroscopy is considered the gold standard for the diagnosis of meniscal lesions. We measured the length of the meniscal lesions in order to correlate it to the clinical findings.
Results: From the clinical examination, we got the following data: McMurray's test: sensitivity 79.7%, specificity 78.5%, accuracy 79.4%, positive likelihood ratio 3.7, negative likelihood ratio 0.2. Apley's test: sensitivity 83.7%, specificity 71.4%, accuracy 80.3%, positive likelihood ratio 2.9, negative likelihood ratio 0.2. The composite assessment is strictly dependent on how the discordance of the two tests is evaluated. The assessment of the clinical tests was done even in relation to medial or lateral meniscal lesion. No statistical difference was found about the length of the meniscal tear. MRI gave the following results: sensitivity 78.3%, specificity 85.7%, accuracy 80.3%.
Conclusions: If we use, as diagnostic means, McMurray's and Apley's clinical tests and MRI as imaging procedure, we have an accuracy of about 80%. It is important to keep in mind that it is not possible to have the absolute certainty of make a correct diagnosis in case of meniscal lesions. Patients, too, have to be informed about the risk of a negative arthroscopy.