[MRI vs. arthroscopy in the diagnosis of cartilage lesions in the knee. Can MRI take place of arthroscopy?].

INTRODUCTION

The accuracy of magnet resonance imaging in diagnosing cartilage lesions is discussed controversially. The sensitivity of this examination ranges from 15 % to 96 %. Clinical evidence demonstrates that cartilage lesions, diagnosed by MRI, were not confirmed in arthroscopy. The purpose of this prospective study was to analyse the practicability of replacing arthroscopy by MRI in diagnosis of cartilage lesions.

PATIENTS AND METHODS

195 patients with acute or chronic knee pain were examined by reason of a pathological clinic result by MRI preoperatively. In group A (n = 86), a standard program was performed in the radiological department of German Army Hospital (sagittal STIR TSE und PD TSE, coronary und transversal T2 FFE [TR = 660 ms, TE = 18 ms, FA = 30 degrees, 512er-Matrix]), in 21 patients (subgroup AK) a cartilage specific sequence (fs T1 W FFE) without gadolinium was added. Patients in group B (n = 88) were examined in a private outpatient clinic (sagittal T1 SE, T2 SE and T2 FLASH [TR = 608 ms, TE = 18 ms, FA = 20 degrees, 256er-Matrix]) with the use of gadolinium. A clear clinical diagnosis had to be performed before MRI examination.

RESULTS

156 lesions of the cartilage were detected arthroscopically. The sensitivity of the examination was in group A 33 %; group B 53 %; group AK 38 %, specificity in group A 99 %; group B 98 % and group AK 98 %. The positive and negative predictive values were in group A 75 %/98 %; group B 48 %/98 % and in group AK 50 %/97 %.

CONCLUSION

MRI was not able to detect reliable cartilage lesions. Until now, arthroscopy is the golden standard to detect cartilage lesions.