下肢长骨常见部位疲劳骨折影像诊断

THE IMAGING DIAGNOSIS OF FATIGUE FRACTURE IN COMMON SITES OF LOWER EXTREMITY

目的探讨下肢长骨常见部位疲劳骨折的影像学表现,提高对疲劳骨折的认识和诊断水平。方法收集我院1998年9月—2012年2月经临床随访证实的44例下肢长骨常见部位疲劳骨折病人的临床资料,对部分影像学征象进行定量分析。结果 40例行X线平片检查,见骨膜反应和骨痂39例,骨髓腔密度增高31例,皮质异常20例。19例行CT检查,均见骨膜反应和骨痂,骨髓腔密度增高14例,皮质异常15例,周围软组织异常16例,其中有软组织包块3例。骨膜反应长度平均77.35mm,其中骨端侧平均30.79mm,骨干侧平均46.55mm,两者差异无统计学意义(P>0.05)。骨痂最大厚度平均5.65mm。软组织包块最大厚度为7.00mm。17例行MRI检查,均见骨髓水肿、软组织改变及骨膜异常,皮质异常16例,髓腔内见条片状低信号线影10例。骨髓水肿长度平均131.37mm,其中骨端侧平均68.06mm,骨干侧平均63.31mm,两者差异无统计学意义(P>0.05)。软组织水肿长度平均129.62mm,其中骨端侧平均55.68 mm,骨干侧平均73.94 mm,两者差异有显著性(t=2.50,P<0.05)。骨髓水肿长度与软组织水肿长度差异无显著性(P>0.05),二者之间呈正相关(r=0.64,P<0.01)。结论下肢长骨常见部位疲劳骨折影像学表现有一定的特征,MRI能早期显示骨髓、软组织及骨膜异常,并显示病变范围,有利于疾病的早期诊断及鉴别诊断。

Objective To study the imaging features of fatigue fracture in the common sites of lower extremity and improve the understanding and diagnosis of this kind of fracture. Methods Clinical data of 44 cases of fatigue fracture in common sites of lower extremity-confirmed by clinical follow-up conducted during September 1998—February 2012 were collected,and a quantitative analysis was done for part of their imaging signs. Results A plain radiography was done in 40 patients,of whom,39 were seen with periosteal reaction and bony callus,31 with increasing density of bone marrow cavity.A CT check was carried out in 19 patients,all of them showed periosteal reaction and bony callus,14 with increasing density of bone marrow cavity,15 with cortical abnormality,16 with abnormal surrounding soft tissue,of which,soft tissue mass was seen in three cases.The average length of periosteal reaction was 77.35mm—the bone end side being 30.79 mm,and the shaft side 46.55 mm,the difference was not significant（P〉0.05）.The maximum thickness of bony callus was 5.65 mm in average.The maximum thickness of soft tissue mass was 7.00 mm.An MRI check was carried out in 17 cases,bone marrow edema and soft tissue changes could be seen in all of them,cortical and periosteal abnormalities seen in 16 cases,and low-signal line in bone marrow cavity seen in 10 cases.The length of bone marrow edema was 131.37 mm in average,of which,the bone end side being 68.06 mm,and the shaft side 63.31 mm,the difference was not significant（P〉0.05）.The length of soft tissue changes was 129.62 mm in average,of which,the bone end side being 55.68 mm,and the shaft side 73.94 mm,the difference was significant（t=2.50,P〈0.05）.The difference between the length of bone marrow edema and soft tissue changes was not significant（P〉0.05）. Conclusion There are certain imaging characteristics of fatigue fracture in the long bone of commonly seen parts of lower extremity.MRI can early show the abnormalities of bone marrow,soft tissue and periosteum as well as the extent of the disease,which is of value in the early diagnosis and differential diagnosis of this condition.