A Comparative Study On Clinical Signs, MRI Imaging And Arthroscopy Of Meniscal Injuries In Knee Joint

0bjective To compare the reliability and value of clinical signs,MRI imaging and arthroscopy in management of meniscal tears in order to increase the diagnostic rate and identify the indications of arthroscopic surgery.Methods The clinicla signs,MRI imaging and arthroscopy in management of meniscla tears of 56 patients under going MRI examination and diagnostic or operative videoarthroscopy were retrospective1y compared. Among 116 menisci of 58 knee joints,14 menisci were found abnomal signals described as III grade by MRI, while 13 menisci wereproved to be teared by arthroscopy.Three menisci were not found obvious signals described as III grade and were proved to be teared by arthroscopy and one of them suggested possibly teared,whose signals was between grade 1I and grade III in the MRI.Ninety-nine menisci were proved normal both by MRI and arthroscopy, and three of their signals are between grade 1I and grade III in the MRI.Using arthroscopic diagnosis as the standard, the sensitivity,speciifcity, accuracy, positivepredictivevalue(PPV) and negativepredictivevalue(NPV) of clinicla diagnosis and MRI were then claculated respectively . Significant differences between arthroscopic diagnosis and clinical diagnosis or MRI diagnosis were analyzed using statistical method of Chi-square test. The abnormal signals in the menisci were evaluated by the criteria drew by Crues,Mink and Fischer,etc. Results The sensitivity,specificity and accuracy of clinical diagnosis were 75% ,75% and 78.2% respectively.There was statistically significant difference between arthroscopic diagnosis and clinical diagnosis.The sensitivity,specificity and accuracy of MRI diagnosis were 81.3% ,99% and 96.6% respectively.The difference between arthroscopic diagnosis and MRI diagnosis had no statistically significance and can be used as an important examination before knee arthroscopy.The signal described as III grade in the menisci was a reliable sign of complete meniscal tears( P<0.01 ),which was adefinite indication for surgery.The signal described as grade 1I in the menisci rarely suggested meniscal tears.The signal between grade1I and grade II1 was found no diference in diagnosing meniscal tears comparing with the signal described as grade II ( P>0.05 ).Conclusion MRI is a reliable,noninvasive diagnostic tool for meniscal tears and can be used as an importan t examination before knee arthros copy with MRI exam ination combining with the clinical signs,diagnotic rate of meniscal tears can be increased.Unnecessary arthroscopic therapy could be avoided.Besides, the signal described as II1 grade in the menisci is a reliable sign of complete meniscal tears.The patients with abnorma1 signal described as III grade in the menisci usually need surgery.