MRI 对一过性髌骨外侧脱位的诊断价值

【目的】探讨一过性髌骨外侧脱位(TLPD)患者的 MRI 影像特征。【方法】回顾性分析本院收治的56例 TLPD 患者的临床 MRI 资料,对有无骨或软骨损伤、关节内游离体、内侧髌股韧带损伤、关节积液、髌骨半脱位和外倾、解剖异常等进行判断分析,并结合临床资料、X 线片及关节镜图像分析,总结该类患者影像学特征。【结果】初次就诊时被误诊、漏诊有26例(46.4%)。MRI 显示56例(100%)患者均存在“对吻征”所致不同程度的骨软骨损伤,其中股骨外髁外侧前缘有10例(17.9%)软骨骨折,骨软骨骨折6例(10.8%)；髌骨下极内侧缘有16例(28.6%)软骨骨折,10例(17.9%)骨软骨骨折。关节内游离体20例(35.7%)；50例(89.3%)有不同程度的内侧髌股韧带损伤和关节积液；髌骨半脱位和外倾36例(64.3%)；56例患者中存在股骨滑车发育不良者 16例(28.6%),高位髌骨者14例(25.0%),TT-TG>20 mm 者6例(10.7%)。【结论】TLPD 患者误诊、漏诊率较高,MRI 能准确地显示各解剖结构的损伤及程度,有助于明确诊断,应作为该病的首选检查方法。

Diagnostic Value of Magnetic Resonance Imaging in Transient Lateral Patellar Dislocation

Objective]To evaluate the characteristics of magnetic resonance imaging(MRI)in transient lateral patellar dislocation .Methods]MR images of 56 patents confirmed by clinic as transient lateral patellar dislocation were retrospectively reviewed.Bone injury,cartilage injury,loose bodies,medial patellofemoral lig-ament injury,intra-articular effusion,patellar subluxation and anatomic abnormalities of the knee were ana-lyzed,combined with clinical data,X-ray and arthroscopic image analysis and the imaging features of the pa-tients were summarized.Results]There were 26 cases of misdiagnosis and missed diagnosis during the first visit(46.4%).MRI examination displayed the osteochondral injuries in all 56 patients (100%),among which cartilage fracture in lateral femoral condyle front accounted for 10 cases (1 7.9%),bone cartilage fracture ac-counted for 6 cases (10.8%);There were 1 6 cases (28.6%)of the medial margin of the patella,10 cases (1 7.9%)of the fracture of the bone and cartilage,20 cases (35.7%)of intra-articular corpus liberum,50 ca-ses (89.3%)with medial patellofemoral ligament injury and joint effusion in different degrees;Subluxation of patella and camber acconted for 36 cases (64.3%);among 56 cases of patients,1 6 cases (28.6%)presented femoral trochlear dysplasia,14 cases (25.0%)patella alta and 6 cases TT--TG>20 mm (10.7%).Conclu-sions]The missed and misdiagnosis rates of transient lateral patellar dislocation are fairly high.MRI can clear-ly display the anatomical structure injuries of the knee and has important diagnostic value of transient lateral patellar dislocation,thus,is recommended the first assistant examination for this disease.