沈 煜,沈惠良,方秀统,张文博
(1.首都医科大学宣武医院骨科,北京100053;2.首都医科大学世纪坛医院骨科,北京100038;3.北京军区总医院肾内科,北京100700)
MRI对骨质疏松性椎体压缩骨折患者椎体终板和骨折椎体邻近间盘损伤的评估及其临床意义
沈 煜1,沈惠良1,方秀统2,张文博3
(1.首都医科大学宣武医院骨科,北京100053;2.首都医科大学世纪坛医院骨科,北京100038;3.北京军区总医院肾内科,北京100700)
目的:探讨通过MRI评价急性或亚急性骨质疏松性椎体压缩骨折 (OVCF)患者椎体终板损伤和骨折椎体邻近间盘损伤的关系,为OVCF的诊断提供依据。方法:选择行椎体成型术的66例 (76个骨折椎体)老年OVCF患者临床资料,通过MRI评估患者骨折椎体终板和骨折椎体邻近间盘的损伤情况。结果:76个骨折椎体中57个椎体有终板损伤 (75%)。57个有终板损伤的骨折椎体中27个椎体只有上终板损伤 (47%),22个椎体同时有上下终板损伤 (39%),8个椎体只有下终板损伤 (14%)。76个骨折椎体中48个椎体有邻近间盘损伤(63%)。48个有邻近间盘损伤的骨折椎体中22个间盘损伤位于骨折椎体上方 (45%),19个骨折椎体同时有上下间盘损伤 (40%),7个间盘损伤位于骨折椎体下方 (15%)。结论:骨折椎体终板损伤与邻近椎间盘损伤有密切关联,提示临床诊断和治疗中应重视骨折椎体的终板损伤及邻近间盘损伤。
椎体骨质疏松性压缩骨折;椎体终板损伤;间盘损伤;磁共振成像
骨质疏松性椎体压缩骨折 (osteoporotic vertebral compression fracture,OVCF)是胸腰背部顽固性疼痛的根源,磁共振成像 (magnetic resonance imaging,MRI)已被广泛应用于椎体压缩性骨折的诊断,MRI影像不仅能识别椎体压缩畸形,同时也能通过MRI影像上所显示的椎体骨髓水肿信号诊断是否发生急性或亚急性椎体骨折[1]。椎体成型术使骨折椎体获得稳定性并能明显缓解疼痛[2]。由于终板和椎间盘纤维环均具有丰富的神经末梢支配,终板骨折和间盘损伤是诱发腰背部疼痛的重要因素之一[3-4]。骨折椎体终板和邻近椎间盘损伤与临床症状、手术治疗方案选择及术后临床愈后有关联,本研究旨在通过MRI影像探讨急性或亚急性OVCF患者中椎体终板和骨折椎体邻近间盘损伤的发生率。
1.1 一般资料 选择2009年1月—2012年6月在本院行椎体成型术的老年OVCF患者66例(76个骨折椎体)的临床资料。老年OVCF患者均由MRI诊断为急性压缩骨折或是亚急性压缩骨折,其中男性19例,女性47例,年龄60.1~88.5岁,平均年龄 (76.6±9.2)岁。急性OVCF或是亚急性OVCF诊断标准:骨密度检查<-2.5个标准差,急性OVCF在6周之内,亚急性OVCF为6周~3个月,陈旧性骨折为超过3月。入选标准:年龄>60岁,骨密度检查<-2.5个标准差,均是急性压缩骨折或是亚急性压缩骨折;排除标准:年龄≤60岁,骨密度检查≥-2.5个标准差,由肿瘤导致的椎体骨折及陈旧性骨折。本组所有急性压缩骨折患者均经过5d~2周的保守治疗后,患者腰背部疼痛症状仍剧烈,伴活动明显受限,生活不能自理,无神经压迫症状表现,影像学无椎体中柱破坏,无脊髓受压。
1.2 MRI检查方法 采用1.5T超导型磁共振扫描仪 (Philips Achieva公司),使用脊柱成像线圈对患者行常规矢状面 (T1WI、T2WI和STIR)和横断面 (T2WI)扫描。扫描参数:矢状面T1WI,TR/TE 300ms/7.8ms;T2WI,TR/TE 3000ms/120ms;STIR,TR/TE 2 500ms/60ms;层厚4mm,层间距0.4mm,FOV 300mm,矩阵252×336。
1.3 检测指标的观察及评价标准 观察内容包括:骨折椎体形态改变、急性和陈旧压缩骨折在各序列的信号改变和每个骨折椎体是否有终板和邻近间盘的损伤。终板损伤在MRI影像上显示为终板水肿、终板液体征、终板软骨连续性中断、成角或是间盘突进终板内;间盘损伤在MRI影像上显示为间盘水肿或形态学改变。
66例 (76个骨折椎体)患者中,25例骨折部位位于胸椎,32例骨折部位位于腰椎,8例骨折部位分别位于胸椎和腰椎2个椎体,1例骨折部位分别位于胸椎和腰椎3个椎体 (1个椎体位于胸椎,2个椎体骨折位于腰椎)。在MRI影像上可观察到57个骨折椎体有终板损伤 (75%),表现为终板水肿、终板液体征、终板软骨连续性中断、成角或是间盘突进终板内;57个有终板损伤的骨折椎体中27个骨折椎体只有上终板损伤 (47%),22个骨折椎体同时有上下终板损伤 (39%),8个骨折椎体只有下终板损伤 (14%)。上终板损伤总构成比为64% (49/76),下终板损伤总构成比为39% (30/76),骨折椎体上终板损伤的构成比高于下终板损伤。在MRI影像上可观察到48个骨折椎体有邻近间盘损伤 (63%),表现为间盘水肿或者是形态学的改变;48个有邻近间盘损伤的骨折椎体中,22个间盘损伤位于骨折椎体上方 (45%),19个骨折椎体同时有上、下间盘损伤 (40%),7个间盘损伤位于骨折椎体下方 (15%)。骨折椎体上方间盘损伤总构成比为54% (41/76),骨折椎体下方间盘损伤总构成比为34% (26/76),骨折椎体上方间盘损伤构成比高于骨折椎体下方间盘损伤构成比。见图1。
图1 OVCF患者终板损伤和间盘损伤MRI表现Fig.1 MRI images of endplate injury and intervertebral disc injury of OVCF patientsA:Superior endplate injury;B:Superior and inferior endplate injuries;C:Inferior endplate injury;D:Upper intervertebral injury;E:Upper and lower intervertebral injuries;F:Lower intervertebral injury.
OVCF被认为是老年人健康衰退的前哨征,随着社会老龄化进展这一问题将更加严重。OVCF患者早期因疼痛、不能站立导致生活质量急剧下降,同时诱发老年患者术前并存疾病发作以及引起新的并发症出现;晚期受伤椎体进一步塌陷,疼痛和后凸畸形加重,导致胸腔容积缩小、通气障碍、缺氧和心肺功能障碍,病死率明显增加,成为危害老年人健康的重要疾病。近年来,球囊扩张椎体后凸成形术 (PKP)因创伤小、止痛效果好和并发症少等优点成为治疗OVCF的有效方法[5]。MRI影像能准确判断椎体是否有骨折,绝大多数临床医生均将治疗重点放在骨折椎体部位[1],而对脊柱其他结构的损伤关注很少,如椎体终板、椎间盘、关节突和脊柱周围肌肉结构,这些脊柱结构对维持脊柱的稳定均起到重要的作用,如椎间盘不仅在脊柱活动中起重要的作用,同时在脊柱负荷传导中也起重要作用;同时终板和间盘纤维环均具有丰富的神经末梢支配,终板骨折和间盘损伤均诱发腰背部疼痛的重要原因[3-4]。本研究结果证实:在OVCF患者中,终板骨折和骨折椎体邻近间盘损伤发生率很高。阅读MRI影像资料时,临床医生不仅应重视骨折椎体形态学和骨髓信号的变化,同时也应仔细观察骨折椎体终板和邻近间盘形态学和信号密度的变化。骨折椎体邻近椎体终板信号密度的变化往往暗示又有1个新的椎体骨折。微小的终板骨折往往是椎体成型术后胸背部或是腰背部疼痛的一个重要原因。微小的终板骨折随着时间的推移,在以后随访的影像学资料中可以显示出很明显的骨折。
椎体终板和椎间盘纤维环有大量的神经末梢分布,因此椎体终板和间盘损伤是胸背部或是腰背部疼痛的重要原因。当急性或亚急性OVCF患者做正常的伸屈活动 (例如向前弯腰穿袜子)或者做增加轴性负荷的动作 (例如站立或者行走)时,可以刺激终板和间盘复合体损伤区域的神经末梢并引起损伤部位的疼痛。终板和间盘复合体损伤可以导致终板和复合体之间的不稳定,这种不稳定可以是局部损伤区域慢性疼痛的重要原因之一,终板和间盘复合体之间不稳定所导致的慢性疼痛常见于OVCF患者,这是因为胸廓持续的呼吸运动可以阻止终板和间盘复合体的愈合,同样脊柱轴性负荷可以导致间盘和终板之间复合体的分离,这也是局部损伤区域疼痛的一个重要原因。如果椎体成型术术后仍有损伤部位的疼痛,这种疼痛很可能是由于终板骨折不稳定所致[5-6]。
临床医生应了解椎体骨折同时伴有终板骨折的发生率较高。在椎体骨折同时伴有终板骨折患者治疗中,临床医生不仅应知道椎体成型术治疗椎体骨折回复椎体高度是重要的,更要注意恢复椎板、重建终板的完整性和封闭终板骨折裂隙同样重要[7-8]。
OVCF患者中,伴有终板骨折和骨折椎体邻近间盘损伤是手术的绝对适应证。但椎体成型术在治疗椎体骨折同时伴有终板和间盘复合体损伤的患者时,骨水泥渗透到椎间隙发生率较高,所以封闭或者是修复终板裂隙不仅可以避免骨水泥渗透到椎间隙里,同样可以阻止间盘进入终板裂隙,从而恢复间盘正常的生物力学特性,可以使间盘在轴性负荷过程中起到正常的生物力学传导作用[9]。
研究[10-13]报道:骨水泥渗透到椎间隙是导致邻近椎体骨折的危险因素,同样终板骨折裂隙也是导致邻近椎体骨折的危险因素。为了避免这些高危险因素,首先要提高临床医生的诊断意识,要明确诊断是否有终板损伤和间盘损伤,其次封闭或者是修复终板裂隙,最后可通过增加骨水泥的黏稠度降低并发症的发生。
综上所述,终板骨折和间盘损伤在急性或亚急性OVCF患者中发生率较高,终板骨折和间盘损伤与患者的临床症状和术后恢复效果有密切关联,应引起重视。影像诊断医生应在诊断报告上明确OVCF患者是否并发终板骨折和间盘损伤。另外,临床医生应仔细阅读影像学资料,明确骨折椎体的邻近椎体是否有不易察觉的终板骨折,因为邻近椎体的终板骨折意味着出现1个新的椎体压缩骨折。
综上所述,使移位的终板复位、封闭或者修复终板裂隙和使骨折椎体及骨折终板达到稳定是治疗急性或亚急性OVCF并发终板和间盘损伤的治疗原则。
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Evaluation on vertebral endplate injury and adjacent intervertebral disk injury of patients with osteoporotic vertebral compression fractures by MRI and its clinical significance
SHEN Yu1,SHEN Hui-liang1,FANG Xiu-tong2,ZHANG Wen-bo3
(1.Department of Orthopedics,Xuanwu Hospital,Capital Medical University,Beijing 100053,China;2.Department of Orthopedics,Millennium Monument Hospital,Capital Medical University,Beijing 100038,China;3.Department of Nephrology,General Hospital,Beijing Military Region,Beijing 100700,China)
ObjectiveTo investigate the relationship between vertebral endplate injury and adjacent intervertebral disk injury of patients with acute or sub-acute osteoporotic vertebral compression fractures(OVC-F)by MRI,and to provide basis for diagnosis of OVCF.MethodsThe clinical data of a total of 66patients with OVCF underwent vertebroplasty(76fracture of vertebral bodies)were selected.The vertebral endplate injury and adjacent intervertebral disk injury of OVCF patients were detected by MRI.ResultsThere were 57vertebral endplate injury in 76fracture vertebral bodies (75%).There were only 27vertebral bodies with vertebral endplate injury in 57fractrue vertebral bodies with endplate injury (47%),and 22vertebral bodies with superior and inferior vertebral endplate injury (39%),and 8vertebral bodies with inferior vertebral endplate injury (14%).There were 48vertebral bodies with intervertebral disc injury in 76fracture vertebral bodies (63%).There were 22intervertebral disc injury located above the fracture of the lumbar spine in 48vertebral bodies with intervertebral disc injury(45%),and 19fracture vertebral bodies with upper and lower intervertebral disc injury (40%),and 7intervertebral injuries located below the fracture of the lumbar spine (15%).ConclusionVertebral endplate injury is frequently associated with the adjacent intervertebral disk injury.The clinical diagnosis and treatment should be emphasized in the fracture vertebral endplate damage and adjacent intervertebral disc injury.
osteoporotic vertebral compression fractures;vertebral endplate injury;adjacent intervertebral disk injury;magnetic resonance imaging
R681.5
A
1671-587Ⅹ(2012)06-1205-04
2012-08-15
北京市科委科研基金资助课题 (3112012)
沈 煜 (1971-),男,北京市人,主治医生,主要从事骨质疏松方面的研究。
沈惠良 (Tel:010-83198641,E-mail:shenhuiliang@medmail.com)