Purpose: Magnetic resonance imaging (MRI) is of great aid in the diagnosis of knee lesions. Most diagnostic studies comparing MRI and arthroscopy have shown good diagnostic performance in detecting lesions of the menisci and cruciate ligaments. Nevertheless, arthroscopy has remained the reference standard for the diagnosis of internal derangements of the knee, against which alternative diagnostic modalities should be compared.
Methods: We took arthroscopy to be the 'gold standard', and we undertook a systematic review of MRI and arthroscopy in the diagnosis of internal derangements of the knee. We used Coleman scoring methodology to identify scientifically sound articles in a reproducible format.
Results: MRI is highly accurate in diagnosing meniscal and anterior cruciate ligament (ACL) tears. It is the most appropriate screening tool before therapeutic arthroscopy. It is preferable to diagnostic arthroscopy in most patients because it avoids the surgical risks of arthroscopy. The results of MRI differ for medial and lateral meniscus and ACL, with only 85% accuracy.
Conclusions: Study design characteristics should also be taken into account whenever a study on MRI assessing its diagnostic performance is designed or reviewed.