跟距骨联合的MRI诊断价值探讨

Clinical value of talocalcaneal coalition on MRI

目的分析跟距骨联合的MRI表现及分型,探讨其临床价值。方法对我院2011年4月—2013年4月间经手术、病理证实的25例跟距骨联合的MRI资料进行回顾性分析,其中男22例,女3例,平均年龄(33.76±13.12)岁;左侧跟距骨联合13例,右侧12例。分析跟距骨联合MRI直接征象和继发征象,按发生部位分型,并按冠状面像(部分结合矢状面像)进行形态分型。结果直接征象中完全骨性联合1例(4%),MRI表现为中距跟关节骨髓连接,纤维性联合14例(56%),软骨性联合10例(40%),MRI上均表现为联合处间隙变窄,边缘不规则。纤维性联合在MR T1WI、T2WI、抑脂序列上均呈低信号;软骨性联合的MRI信号近似软骨或液体,T1WI上呈中等强度信号,T2WI及抑脂序列上呈中等至高信号。继发征象中骨髓水肿20例(80%),"醉酒侍者征"9例(36%),"距骨喙征"3例(12%),"驼背跟骨征"2例(8%),骨折1例(4%)。按部位分型为:中距跟关节7例(28%),后距跟关节4例(16%),关节外型14例(56%),前距跟关节5例(20%)均合并与其他跟距骨联合。按形态分型为:Ⅰ型14例(56%),Ⅱ型3例(12%),Ⅲ型7例(28%),Ⅳ型1例(4%)。结论 MRI能够清晰显示跟距骨联合的组织类型、发生部位和形态等,可为临床提供有价值的诊断信息。

Objective To analyze the MRI manifestations and classifications of talocalcaneal coalition and to explore its clinical value. Methods MRI manifestations of 25 cases of talocalcaneal coalition confirmed by operation and pathology from April 2011 to April 2013 were reviewed retrospectively in this study. There were 22 males and 3 females, mean age was33.76±13.12 years. Thirteen cases had left side of talocalcaneal coalition, and 12 cases had right side of talocalcaneal coalition.Direct and secondary MRI signs of talocalcaneal coalition were analyzed. Talocalcaneal coalitions were classified according to location and morphology on coronal images. Results Among direct MRI signs, there was 1 case of osseous coalition（4%）demonstrating continued bone marrow across middle talocalcaneal joint; fourteen cases of fibrous coalition（56%） and 10 cases of cartilaginous coalition（40%） demonstrating narrowed joint space and irregularity of the bone interface. Fibrous coalition demonstrated low-signal intensity on T1-weighted, T2-weighted and fat-suppressed sequences across the affected joint;cartilaginous coalition demonstrated intermediate signal on T1 WI and intermediate to hyperintensity on T2 WI and fat-suppressed sequence. Among secondary MRI signs, there were 20 cases of bone marrow edema adjacent to the coalition（80%）;nine cases of the ＂drunken waiter sign＂（36%）; three cases of ＂talar beak sign＂（12%）; two cases of ＂humpback calcaneal sign＂（8%）; one case of fractures in talocalcaneal coalition（4%）. Locational types： seven cases of middle facet talocalcaneal coalition（28%）, four cases of posterior facet talocalcaneal coalition（16%）, fourteen cases of extra-articular type（56%）, and 5 cases of anterior facet talocalcaneal coalition（20%） combined with the other part of talocalcaneal coalition. Morphological types： typeⅠ： fourteen cases（56%）, type Ⅱ： three cases（12%）, typeⅢ： seven cases（28%）, and type Ⅳ： one case（4%）. Conclusion MRI can clearly demonstrate histologic subtypes, location and morphology of talocalcaneal coalition, providing valuable diagnostic information for clinicians.