邻近骶髂关节原发恶性骨肿瘤跨关节侵犯的MRI研究

MRI Study on Transarticular Invasion of Primary Malignant Bone Tumors Abutting the Sacroiliac Joint

目的观察邻近骶髂关节的骨原发恶性肿瘤跨关节侵犯的MRI表现,比较不同部位、病理类型和分级的恶性骨肿瘤跨关节侵犯的发生率及侵犯方式之间是否存在差异性。方法分析2004年1月至2015年6月间经手术病理证实的93例邻近骶髂关节的髂骨（69例）和骶骨（24例）原发恶性骨肿瘤患者的临床及MRI资料,男60例,女33例,年龄4~74岁,平均32岁,包括普通型骨肉瘤29例,尤文肉瘤16例,中央型软骨肉瘤35例,脊索瘤13例。按病理恶性程度分为恶性程度较高肿瘤组和恶性程度较低肿瘤组。跨骶髂关节侵犯分为经韧带连结、经关节软骨和经关节周围三种方式,多种方式并存出现者按每种方式分别计数1次。数据处理采用SPSS 17.0统计软件进行统计学分析。结果邻近骶髂关节的骨原发恶性肿瘤跨骶髂关节侵犯27例,包括骨肉瘤15例（51.7%）,尤文肉瘤7例（43.8%）,软骨肉瘤4例（11.4%）和脊索瘤1例（7.7%）。髂骨和骶骨原发恶性骨肿瘤跨关节侵犯发生率之间的差异无统计学意义（χ~2值=1.06,P〉0.05）。恶性程度较高肿瘤组和恶性程度较低肿瘤组间跨关节侵犯的差异具有统计学意义（χ~2值=16.68,P〈0.01）。27例肿瘤经韧带连结25次、经关节软骨13次和经关节周围5次方式跨骶髂关节侵犯,此三种侵犯方式的几率之间差异均具有统计学意义（P〈0.05）,恶性程度较高肿瘤组与恶性程度较低肿瘤组间的三种方式跨关节侵犯的几率差异均无统计学意义（P〉0.05）。结论 MRI对显示邻近骶髂关节的骨肿瘤跨关节侵犯具有非常高的敏感性。邻近骶髂关节的髂骨和骶骨原发恶性骨肿瘤跨骶髂关节侵犯发生率无明显差异,普通型骨肉瘤和尤文肉瘤跨骶髂关节侵犯率明显高于恶性程度较低的中央型软骨肉瘤和脊索瘤。骨肿瘤多经韧带连结跨关节侵犯,其跨关节侵犯方式与肿瘤恶性程度无关。

Objective To compare the incidences of transarticular invasion and transarticular routes between primary malignant bone tumors abutting the sacroiliac joint（SIJ） with different locations,pathological types and malignant grades by observing their MR characteristics.Methods Retrospectively studied the preoperative magnetic resonance（MR） imaging of 93 consecutive patients（60 male,33 female; age range 4-74 years,mean age 32 years） with primary malignant bone tumors abutting the SIJs（69 iliac tumors and 24 sacral tumors） from January 2004 to June 2015,which were proved by postoperative pathology,including 29 conventional osteosarcomas,16 Ewing＇s sarcomas,35 central chondrosarcomas and13 chordomas.The tumors were categorized into two groups according to their malignant grade： higher grade group and lower grade group.Tumors abutting the SIJ could transarticularly infiltrate the opposite bone in three routes： extending across the ligamentous portion,cartilaginous portion and periarticular tissues of the SIJ.We counted it in each route respectively when two or more routs coexisted in one patient.Statistical study was progressed with SPSS software 17.0.Results 27 primary malignant bone tumors abutting the SIJs showed imaging evidence of transarticular SIJ invasion,including 15 osteosarcomas（51.7%）,7 Ewing＇s sarcomas（43.8%）,4chondrosarcomas（11.4%） and 1 chordoma（7.7%）.There were no statistical differences between the incidences of transarticular invasion by primary malignant iliac and sacral tumors（χ~2= 1.06,P 〈0.05）.While,the incidences of transarticular invasion in the higher grade group and lower grade group were statistically different（χ~2= 16.68,P 〈0.01）.Of the 27 tumors showed imaging evidence of transarticular SIJ invasion,25 tumors infiltrated through the posterior part of the joint,13 tumors infiltrated through the anterior part of the joint,and 5tumors infiltrated through periarticular tissues.There were statistical differences between these three routes of transarticular invasion in our study（P 〈0.05） and the differences of incidences of any route between higher grade group and lower grade group were not statistical significant（P 〈0.05）.Conclusion MR shows a very high sensitivity on revealing transarticular invasion of bone tumors abutting the SIJ.There were no significant differences between the incidences of transarticular invasion by primary malignant iliac and sacral tumors abutting the sacroiliac articulation.The incidences of transarticular invasion by conventional osteosarcomas and Ewing ＇s sarcomas were obviously higher than that of central chondrosarcomas and chordomas,which were less malignant.Tumor invasion across the SI articulation favours its interosseous ligamentous portion,which has nothing to do with its malignant grade.