CLINICAL ARTICLE Kor J Spine 5(2):5-9, 28 흉요추부골절에서골절척추체의방사선학적소견과후방인대복합체손상과의관계 이화여자대학교의과대학신경외과학교실 조용재 Relationships between Radiological Change of Fractured Vertebrae and Posterior Ligament Complex Injury in Thoracolumbar Fracture Yong-Jae Cho, M.D. Department of Neurosurgery, Ewha Womans University School of Medicine, Seoul, Korea Objective: To investigate the relationships between posterior ligament complex injury and plain radiographic parameters in thoracolumbar spinal fractures. Methods: Forty patients with thoracolumbar fractures who had operated from Jan 2 to Dec 27 were studied. For the evaluation of stability of injured vertebrae, we used the radiographic parameters which were wedge angle, Cobb's angle, compression rate measured on the plain radiographs, and the presence of posterior ligament complex injury on MRI. Results: In the compression fracture group, the compression rate was statistically significant high in the posterior ligament complex injury patient (p=.3). In the burst fracture group, the wedge angle, Cobb's angle and the compression rate were high in the posterior ligament complex injury patient, which were all statistically significant (p=.2,.1,.1). Conclusions: The presence of a posterior ligament complex injury is important in the treatment of the thoracolumbar spine fracture. The status of the posterior ligament complex should be integrated into future classification schemes of thoracolumbar spine fractures. Key Words: Thoracolumbar spine fracture ㆍ Posterior ligament complex 서 론 흉요추부골절의치료는각각다른특성을가진여러구조물들의복합손상이기때문에혼돈을초래하기쉽고손상의분류도어렵다 1,4,5). 기존의흉요추부골절의분류는신경학적상태나척추인대손상등에대한기술은없어서수술적응증이나수술방법의결정에부족한점이많았다. 이러한단점을개선하고자여러연구자들에의해다양한손상분류법이제안되고있다 1,11). 이들흉요추부골절에대한새로운분류법들은후방인대복합체 (posterior ligament complex, PLC) 의손상유무를중요한인자로포함시키고있다. 197 년대 Holdsworth 는척추의안정에관여하는연부조직중극상인대 (supraspinous ligament), 극간인대 (inter- spinous ligament), 척추관절막 (capsule of facet), 황색인대 (ligament flavum) 을통칭하여후방인대복합체 (posterior ligament complex, PLC) 로정의하고, 그중요성을주장하였다 ). 근래들어척추외상에자기공명영상 (magnetic resonance imaging, MRI) 의사용이증가함에따라, 연부조직의손상을파악할수있게되었고, 이를이용하여치료방침을결정하는데도움을얻을수있게되었다 2,9,15,1). 흉요추부압박골절과방출성골절의수술적또는보존적치료방법에서유용하게이용되는추체높이와척추후만각에대한지침은여러문헌에보고되어있으나, 아직도논란의대상이되고있으며, 많은저자들은연부조직의손상정도가예후에필수적인변수가된다고생각하고있으나, 진단에는많은어려움이있다 3,19). MRI 의등장은추간판, 종판, 후방인대복합체, 척수신경등연부조직손상의 Received: March 1, 28 Accepted: April 28, 28 Published: June 3, 28 Corresponding Author: Yong-Jae Cho, M.D. Address of reprints: Department of Neurosurgery, Ewha Womans University Mok-Dong Hospital, 911-1 Mok-Dong, YangChun-Gu, Seoul, 158-71, Korea Tel: +82-2-25-258, 38-, Fax: +82-2-255-948, E-mail: yongcho@ewha.ac.kr Kor J Spine 5(1) March 28 5
YJ Cho Table 1. Summary of characteristics in 4 patients Compression Fx (n=22) Burst Fx (n=18) M : F Mean Age (yrs) Location of Fx T1 T11 T12 L1 L2 IPLC (+) Neurologic status* A B C D E 4(18.2%) 2 2 2 : 14 45.3(17-8) 14 1 4 12(.7%) 3 3 1 5 IPLC: Injury of posterior ligament complex, *described by Frankel classification at admission Fx: Fracture 진단에있어획기적인전기를마련했으며, 널리이용되고있다. 다른저자들에의해수술적소견과 MRI 소견과의일치성에대해많은보고가있어왔다 15,1). 일반적으로흉요추부골절에서골절추체의방사선적계측인자로국소후만각 (kyphotic angle, Cobb s angle), 설상각 (wedge angle), 전방추체의압박률 (anterior compression rate) 등이있으며, 이를측정하여골절추체의손상정도를파악하고있다 1,4,7). 본연구의목적은흉요추부압박골절및방출성골절환자에서후방인대복합체의손상유무와골절척추체의방사선학적계측치와의연관관계를분석하여향후진단과치료방법결정에도움을주고자한다. 대상및방법 1. 대상 저자들의병원신경외과에서 2 년 1 월부터 27 년 12 월사이에골다공증및종양과관련된병적골절을제외한외상성흉요추부골절 ( 제 11 흉추 - 제 2 요추 ) 로진단받고, 수술적치료를받은환자 4 명을대상으로하였다. 대상환자들의수술전단순방사선사진, CT, MRI, 의무기록을후향적으로검토하였다. 골절의분류는 Denis 의분류를이용하였으며, 이들은남자 2 명, 여자 14 명이었고, 평균연령은 45.3 (17~8) 세이었다 (Table 1). 2. 방법 평면방사선사진은수상초기에앙와위에서촬영한측면사진을이용하였고, 자기공명영상촬영에서는 T1, T2- weighted, fat suppression 의시상면과축상면에대한영상 Table 2. Oner s classification of injury of posterior ligament complex Finding Injury of Posterior ligament complex (IPLC) Grade 1: No evidence of injury Grade 2: Oedema in the interspinous space without evident discontinuity or elongation Grade 3: Elongation of the interspinous space without evident discontinuity Grade 4: Clear disruption of the PLC Grade 3 or 4: IPLC (+) 을이용하였다. 측면평면방사선사진에서국소후만각 (kyphotic angle, Cobb s angle), 설상각 (wedge angle), 전방추체의압박률 (anterior compression rate) 을측정하였다. 후만각은골절추체의상부추체의상부종판과하부추체의하부종판이이루는각을 Cobb s method 로측정하였고, 설상각은골절추체의상하종판이이루는각으로, 골절추체의전방압박률은골절추체의상하추체전방높이의평균값에대한골절척추의전방추체높이의백분율로하였다 (Fig. 1). 자기공명영상에서후방인대복합체의손상정도는 Oner 등이 1999 년에발표한흉요추부골절에서연부조직손상의 MRI 소견기준에따라분류하였으며, 신연과파열이있는경우를후방인대복합체손상군으로하였다 (Table 2). 대상환자를중주의골절유무에따라압박골절과방출성골절군으로구분하고, 각각을후방인대복합체손상군과비손상군으로나누어후만각, 설상각, 전방추체의압박률과후방인대복합체손상과의관계를분석하였다. 통계 Kor J Spine 5(1) March 28
Thoracolumbar spine fracture, Posterior ligament complex 학적분석은 student t-test (SPSS 1 for Window, Chicago, IL) 로하였으며, 유의도.5 이하인경우를통계학적의의가있는것으로판단하였다. 결 과 1. 일반적결과 압박골절 22 례, 방출성골절 18 례이었다. 골절된척추의위치는제 1 흉추가 례, 제 11 흉추가 례, 제 12 흉추가 14 례, 제 1 요추가 1 례, 그리고제 2 요추가 4 례였다. 후방인대복합체의손상은 1 례 (4%) 에서손상소견이관찰되었으며, 압박골절에서는 4 례 (18.2%), 방출성골절에서는 12 례 (.7%) 이었다. Frankel 의신경학적상태의분류에따르면, A 례, B 3 례, C 3 례, D 3 례, E 25 례였다 (Table 1). 2. 후만각 (Kyphotic angle, cobb s angle) 압박골절에서후방인대복합체손상군에서는평균 22. ±1.8 도, 비손상군에서는 21.2±.5 도로양군간에차이를보이않았으나 (p=.77), 방출성골절에서손상군 3.1±2.4 도, 비손상군 1.4±5.8 도로양군간에통계학적으로의미있는차이를보였다 (p=.2) (Table 3). 3. 설상각 (Wedge angle) 압박골절에서후방인대복합체손상군에서는평균 23.9 ±3.1 도, 비손상군에서는 3.7±2.4 도로후방인대복합체손상군에서설상각이컸으나, 양군간에통계학적으로유의한차이를보이지는않았다 (p=.42). 방출성골절에서손상군 34.9±2.4 도, 비손상군 18.3±4.8 도로설상각의차이가통계학적으로유의하게컸다 (p=.1) (Table 3). 4. 골절추체의압박율 (Compression rate) 압박골절에서후방인대복합체파열이있는군의압박정도는평균 5.2±5.8%, 비손상군에서는 42.1±.8% 로후종인대손상군에서추체압박의정도가심하였고 (p=.3), 방출성골절에서는손상군에서.1±4.2%, 비손상군에서 48.7 ±.7% 를보여 (p=.1) 압박골절과방출성골절에서후방인대복합체손상이있는군에서골절추체의압박률이통계학적으로유의하게더높았다 (Table 3). Fig. 1. Measurement of Radiological Parameters, K( ): Kyphotic angle by Cobb s method, W(?): wedge angle, Anterior compression rate(%) = F/ (A1 + A2)/2 x 1, A: Anterior body height, F: Fractured vertebral anterior height. Fig. 2. L1 compression fracture (A) Preoperative plain radiograph with radiographic parameters, (B) Preoperative T1-weighted MRI (Arrow: elongation of the interspinous space without evident discontinuity). Table 3. Radiologic analysis according to Injury of Posterior ligament complex Radiological Parameter Kyphotic Angle Wedge Angle Compression Rate Compression Fracture Burst Fracture IPLC (+) IPLC (-) p-value IPLC (+) IPLC (-) p-value 22.±1.8 23.9±3.1 5.2±5.8% 21.2±.5 3.7±2.4 42.1±.8%.77.42.3* 3.1±2.4 34.9±2.4.1±4.2% 1.4±5.8 18.3±4.8 48.7±.7%.2.1*.1* IPLC: Injury of Posterior ligament complex *Statistical significance, p<.5 Kor J Spine 5(1) March 28 7
YJ Cho 고 찰 흉요추부골절의손상기전은전주또는중주의축성압박력이고, 이로인한굴곡모멘트에의해후주의손상이발생하는것으로알려져있다 4,5,7). 손상된척추의불안정성은급성혹은만성적으로척추의변형을초래하여신경증상의악화와동통을초래할수가있기때문에불안정성에대한합당한평가와분류가요구된다 12,13). 후방인대복합체의손상비중이높은점은방출성골절의치료에있어유의하게고려해야할점이라고사료된다. 이는전주와중주의골손상이외에도상당한후주의손상이동반됨을추정할수있다. 신경증상이동반되지않은흉요추부골절의치료는손상된운동분절의안정성여부에따라치료방법이달라진다 14,17,18). 일반적으로안정성여부와변형의정도는설상각, 후만각과전방추체높이를이용하며, 후방인대복합체의손상이동반되어있는경우는불안정성으로인한지연성후만변형이증가할가능성이매우높으므로후방고정술로척추를안정화시켜주는것이필요하다고알려져있다 8,17,18). 일반적으로흉요추부압박골절에서 5 % 이상의추체압박이있거나, 후만변형이 2 도이상이면불안정성이있다고생각하여수술적치료의적응증으로삼고있다 7,8,12,13). 198 년대초반부터 Denis 의 3 주이론에따른분류가골절의분류와치료에많이이용되고있으나, 이는평면방사선사진과전산화단층촬영을이용하여손상기전과형태학적특성을중심으로해석한것이기때문에연부조직의손상여부는포함되지않았다 5,9,1). Mehta 등은앙와위에서 5% 이하의추체압박, 후만각이 2 도미만인 28 명의압박또는방출성골절환자의보존적치료중 7 명에서수술적치료로전환하였다고보고하면서앙와위에서의방사선사진보다는기립방사선사진이유용함을보고한바있다 11). 일부저자들은흉요추부압박골절의보존적치료와수술적치료의비교연구에서수술적적응증의기준을더넓혀서, 3% 이상의추체압박이있거나, 15 도이상의후만이있는경우에는추시관찰에서보존적치료의경우후만변형이증가하므로수술적치료를주장하기도하였다 18,2). 이와같이후방인대복합체의손상등을포함하지않은일반적으로 5% 이상의추체압박또는 2 도이상의후만변형을척추의불안정성의기준으로생각하고, 수술의적응증으로삼을경우그불안정성이간과될위험성이있다고생각된다. 이번연구에서흉요추부방출성골절의경우후만각, 설상각, 압박률모두후방인대복합체손상이있는군에서유의하게높았다. 이는전주와중주의골손상이외에도상당한후주의손상이동반됨을추정할수있다. 또한척추체의손상이클수록후방인대복합체의손상이커지며, 후방 인대복합체의손상이있는경우척추체의손상정도도커짐을추정할수있으며, 이로인한불안정성도증가한다고할수있다. 또한, 흉요추부압박골절에서후방인대복합체의손상이있는군에서손상추체의압박률이통계학적으로유의하게높았다. 이는, 압박골절에서도전주의축성압박력에의한골손상과함께후주에상당한이완력이작용한다고볼수있으며, 이를통해보면압박률이높은경우는후방인대손상유무를 MRI 등으로확인하여야함을알수있다. 그리고, 압박골절에서후방인대복합체의손상이있는경우는일반적인수술적응증보다더넓게수술적치료를시행하는것이환자의예후에도움이되지않을까추정해보았다. 결 론 이번연구를통해, 흉요추부방출성골절에서전방추체압박율, 방출성골절에서는설상각, 후만각, 추체의압박율모두가후방인대손상군에서통계학적으로의미있는증가를보였다. 압박골절에서는추체압박율이후방인대복합체손상군에서유의하게높았다. 압박골절에서도후방인대복합체의손상을면밀히평가한후치료방법을선택하여야할것으로사료된다. 또한신경학적상태나후방인대등의상태를포함한흉요추부골절의분류가필요하다고하겠다. REFERENCES 1. Bence T, Schreiber U, Grupp T, Steinhauser E, Mittelmeier W: Two column lesions in the thoracolumbar junction: Anterior, posterior or combined approach? A comparative biomechanical in vitro investigation. Eur Spine J 1:813-82, 27 2. Blumenkopf B, Juneau PA: Magnetic resonance imaging (MRI) of thoracolumbar fractures. J Spinal Disorder 1: 144-15, 1988 3. Choi BG, Bae KJ, Jung ES, Choi ES, Shin JH, Kim MJ, et al: Results of Posterior Short Segment Fixation Cases Which are more than 5% Canal Compromise of Thoracolumbar Burst Fractures. Kor J Spine 4:199-24, 27 4. Defino HL, Canto FR.: Low thoracic and lumbar burst fractures: Radiographic and functional outcomes. Eur Spine J 1:1934-1943, 27 5. Denis F: The three column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine 8:817-831, 1983. Holdsworth F: Fractures, dislocations and fracture-dislo- 8 Kor J Spine 5(1) March 28
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