胫骨上段疲劳性骨折CT、MRI表现

目的探讨胫骨上段疲劳骨折的CT与MRI表现及其形成机制。方法分析经临床随访或手术证实的23例胫骨上段疲劳性骨折的CT和MRI资料。23例均行X线及CT检查,7例行MRI检查。结果23例胫骨上段疲劳骨折均发生在距胫骨膝关节面约5.5～8.5cm之间,CT检查23例在胫骨中上段后方见单层、多层或花边样骨膜增生,其后缘正中略偏内侧见脐样凹陷切迹。16例见斜行骨折线。20例骨皮质松化,23例均表现局部骨髓腔密度增高,未见软组织肿块。MRI表现骨折线及骨膜增生在T1WI和T2WI均呈低信号,骨折线上下邻近髓腔及周围软组织呈边缘模糊的长T1长T2信号。脐样凹陷切迹处见条状长T1短T2信号。结论胫骨上段疲劳骨折的CT表现具有特征性,MRI检查对早期诊断具有较大价值。

CT and MRI Findings of Fatigue Fracture in the Proximal Segment of Tibia

Objective To evaluate the CT and MRI findings and the mechanisms of fatigue fracture in the proximal part of tibia.Methods CT and MRI findings of 23 cases with fatigue fracture in the proximal part of tibia confirmed by operation and/or clinical diagnosis were retrospectively analyzed.All cases were undergone radiography and CT scans,7 cases underwent MRI.Results The fractures in 23 cases were all at 5.5 cm to 8.5 cm distant from the articular surface of tibia.On CT,monolayer,multilayer or lace-form periosteal reaction were found at the proximal part of the tibias in all cases,and there was umbilicated incisure at medial side near the middle of back part of the tibia.Oblique fracture lines in 16 cases,osteoporosis of the cortex in 20 cases and the density of medullary cavities in 23 cases were seen,there were no soft tissue masses.All the fracture lines and periosteal reaction were low signal intensity on T1WI and T2WI,the medullary cavities and the soft tissues near to the fracture lines were low signal intensity on T1WI and high signal intensity on T2WI,and the umbilicate incisure was strip low signal intensity on T1WI and T2WI.Conclusion The fatigue fracture of tibia has characteristic features and MRI is of significant value in early diagnosis.