膝关节自发性骨坏死MRI误诊分析

Analysis of MRI misdiagnosis of spontaneous osteonecrosis of the knee joint

目的探讨膝关节自发性骨坏死的MRI影像特征,分析其误诊原因。方法回顾性分析成都市第二人民医院2012年3月至2017年11月误诊的11例膝关节自发性骨坏死的首诊MRI影像,根据MRI影像特征将样本分为三组:Ⅰ组影像特征为骨质水肿,Ⅱ组影像特征为骨质内低信号线状影,Ⅲ组影像特征为骨质囊变。结果Ⅰ组有3例,表现为股骨髁关节面下骨质水肿,均误诊为骨挫伤。Ⅱ组有2例,表现为股骨内侧髁关节面下线状影,均误诊为剥脱性骨软骨炎。Ⅲ组有6例,表现为关节面下囊变影伴周围低信号带及骨质水肿信号,关节构成骨轻度骨质增生,均误诊为退行性骨关节炎。结论膝关节自发性骨坏死MRI影像表现复杂,误诊常见,应熟悉其MRI影像特征与临床密切关联才能减少误诊。

Objective To investigate explore the MRI features of spontaneous osteonecrosis of the knee joint,and analyze the causes of misdiagnosis. Methods A retrospective analysis was conducted on the first MRI images of11 cases of spontaneous osteonecrosis of the knee joint misdiagnosed in Chengdu Second People’s Hospital from March2012 to November 2017. According to the characteristics of MRI images, the samples were divided into three groups:Group Ⅰ, the imaging features were bone edema; Group Ⅱ, the imaging features were low-signal fracture cleft; GroupⅢ, MRI showed cystic lesions inside the bone. Results There were 3 cases of misdiagnosis in Group Ⅰ, which presented as bone edema under the joint surface of the femoral condyle and were all misdiagnosed as bone contusion. There were 2 cases of misdiagnosis in Group Ⅱ, which showed a linear shadow under the articular surface of the medial femoral condyle and were all misdiagnosed as exfoliative osteochondritis. There are 6 cases of misdiagnosis in Group Ⅲ,which were characterized by cystic degeneration with peripheral low signal band and bone edema signal under the articular surface and by mild bone hyperplasia of the joint, and were all misdiagnosed as degenerative osteoarthritis.Conclusion MRI images of spontaneous osteonecrosis of the knee joint are complex, misdiagnosis is common. Only by familiarizing with the characteristics of MRI images and clinical manifestations can reduce the misdiagnosis.