A comparative study on magnetic resonance imaging and arthroscopy in meniscus injuries in knee joint

Objective To analyze the misdiagnosis of MRI through comparing the results using MRI and arthroscopy in the diagnosis of meniscus injuries of the knee.Methods A study was performed in 126 patients(138 knees) who had knee injury and were considered to be injuried in meniscus.All the knees underwent MRI,in the mean time the physicians from radiology and orthopedics departments read the radiography and evaluated the meniscus injury.Before operation the surgeons of orthopedics department predicted the meniscus damage morphology.Then the physical examination and the arthroscopy were conducted.Finally,the check results of the arthroscopy is considered as the gold standard.The results of MRI and arthroscopy were compared and the accuracy of MRI diagnosis was analyzed.According to the results,we analyzed the reasons of misdiagnosis of MRI.Results A total of 125 knees of meniscus injury were described by MRI and 119 knees of meniscus injury were proven by arthroscopy in 126 patients(138 knees).The sensitivity,specificity and accuracy of MRI diagnosis of meniscus injury were 92.0%,64.3% and 89.9% respectively.We analyzed the misdiagnosis reasons of MRI,and found that MRI was easy to be missdiagnosed in a light meniscus tears.Conclusions MRI is a reliable,noninvasive diagnostic tool for meniscus injury,but the importance of the physical examination should not be neglected.If the results of MRI are negative,the physical examination needs to be done to decide whether the arthroscopy operation should be conducted in order to avoid misdiagnosis.If the result of MRI shows grades Ⅲ type injury,arthroscopy operation is needed.