ORIGINAL ARTICLE J Korean Fract Soc 2017;30(4):173-179 ISSN 1225-1682 (Print) ㆍ ISSN 2287-9293 (Online) https://doi.org/10.12671/jkfs.2017.30.4.173 투시영상시뮬레이션을이용한제 2 형항회전근위대퇴정의이상적삽입점의결정 : 해부학적연구 정진훈ㆍ정구희 경상대학교의과대학창원경상대학교병원정형외과학교실 The Determination of Optimal Entry Point for Proximal Femoral Nail Antirotation-II by Fluoroscopic Simulation: A Cadaveric Study Jin-Hoon Jeong, M.D., Gu-Hee Jung, M.D., Ph.D. Department of Orthopaedic Surgery, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Korea Received July 24, 2017 Revised August 8, 2017 Accepted September 27, 2017 Correspondence to: Gu-Hee Jung, M.D., Ph.D. Department of Orthopaedic Surgery, Gyeongsang National University Changwon Hospital, 11 Samjeongjaro, Seongsan-gu, Changwon 51472, Korea Tel: +82-55-214-3822 Fax: +82-55-214-1031 E-mail: jyujin2001@hotmail.com Financial support: None. Conflict of interests: None. Purpose: This study seeks to determine the anatomically optimal entry point of proximal femoral nail antirotation-ii (PFNA-II ) according to geographic features of Korean cadaveric femoral trochanters for successful reduction of osteoporotic proximal femoral fractures. Materials and Methods: Forty-three adult cadaveric femurs without previous fractures or surgeries were included. Anteroposterior (AP) and lateral images of all femurs and PFNA-II were taken with an image intensifier. Using the image synthesis process via the image editing program (Adobe Photoshop CS6), the optimal entry point was verified and compared with the tip of the greater trochanter (GT) and the cervicotro-chanteric junction on AP images, as well as the width of the trochanter and the neck on lateral images. Results: The optimal entry point of PFNA-II was an average distance of 9.1 mm (range, 7-15 mm) medially from the tip of GT on AP images. The center of the nail was located at an average of 30% (range, 21%-44%) area from the posterior margin of the middle neck, which is an average area of 38% (range, 26%-48%) from the posterior cortex of the trochanter on lateral images. Furthermore, the ideal entry point was at the extended line of the cervico-trochanteric junction. Conclusion: The optimal entry point, which was found to be medial to the tip of the GT and posterior to the center of the middle femoral neck and the trochanter, was at on the extended line of the cervicotrochanteric junction. Key Words: Proximal femur, Trochanteric fracture, Proximal femoral nail antirotation-ii, Entry point, Image synthesis 서론 골다공증성대퇴전자부골절은고령화로인하여급속도로증가되면서치료방법에있어최근많은변화가발생하고 있다. 전통적인압박고나사못고정술은대퇴골외벽골절및과도한활강으로인한고정실패의확률이높아최근들어위치적장점이있어과도한활강을방지하는두부골수형금속정 (cephalomedullary nail) 고정술이많이사용되고있다. 1-4) Copyright 2017 The Korean Fracture Society. All rights reserved. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. www.jkfs.or.kr 173
Journal of the Korean Fracture Society Vol. 30, No. 4, October 2017 그러나대퇴전자부골절의두부골수형금속정의성공적인결과를위해서는적절한정복및이상적인금속정의위치가아주중요한것으로알려져있다. 5-8) 특히골다공증성골절의경우골질이감소되어있기때문에위와같은요건이제대로갖추어지지않으면지연나사의활강 (sliding), 골두천공 (cutthrough), 후방돌출 (cut out), 내반함몰 (varus collapse) 등의합병증이발생할수있다. 2,9,10) 두부골수형금속정은골절부위의기능적정복이이루어진후적절한삽입점에삽입되어고정되어야하며, 부적절한삽입점은부정정복을야기할뿐만아니라적절한고정력을얻지못하여고정실패를발생시키게된다. 11) 대퇴전자부두부골수형금속정고정술에서삽입점이외측에형성된경우금속정이골절면을따라들어가면서골두골편을내반시켜내반부정정렬을초래하게되고또한삽입점이전방에치우친경우근위대퇴골의골절을일으킨다는보고도있다. 8,12,13) 그러므로이러한합병증을줄이면서좋은임상적결과를얻기위해서는적절한수술적수기로서정확한삽입점의선정이매우중요한요소임을알수있다. 그러나이러한정확한삽입점의위치에대한아시아인의해부학적특징연구는많지않은바이에저자들은한국인의실제대퇴골과두부골수형금속정의대표적인종류인제2형항회전근위대퇴정을영상증폭기 (image intensifier) 로촬영후가상합성하는방법을통해전자부의특징을파악하여이상적인삽입점의위치를알아보고자하였다. DePuy Synthes, Oberdorf, Switzerland) 이었으며, 지름은 10 mm, 길이는 200 mm, caput-collum-diaphyseal angle은 130 o 였다. 방사선투과수술용테이블위에서영상증폭기의높낮이는움직이지않고같은높이에서대퇴골과제2형항회전근위대퇴정을촬영함으로써동일한배율이되도록하였다. 그리고촬영된이미지들은영상편집프로그램 (Adobe Photoshop CS6 ; Adobe Systems, San Jose, CA, USA) 을이용하여이상적인위치로합성함으로써내고정이이루어진것으로가상하였다. 가상합성시제2형항회전근위대퇴정의이상적인위치는금속정이전후방및측면영상에서대퇴피질골과충돌이발생하지않으면서나선형칼날이대퇴경부의하방및골두의중앙을통과하도록위치시켰다. 특히전후면에서나선형칼날의상면 (superior surface) 이경부의중앙선 (central line) 을지나도록기준을정해위치시켰다. 14-17) 이상적위치로가상고정된전후면대퇴합성사진에서대전자부상부피질골과대퇴정의근위부정중앙을지나는이분선과의교차점을이상적삽입구를선정하였으며이를대전자부첨부와의수평거리를측정하였다 (Fig. 2). 거리의측정은영상증폭기로전후면촬영시투시눈금자를함께촬영하는방식으로하여증폭에따른오차를줄이고자하였다. 대퇴골측면영상에서는납선으로표시된대퇴경부둘레의정중앙점을정하고, 이점을지나는수평선을긋고연장하 대상및방법 해부학실험실에보관중인한국인성인대퇴골에서수술및외상의흔적이없으며육안적인기형이관찰되지않는 43 개를대상으로하였으며, 각대퇴골의나이, 성별및골다공증여부는확인할수없었다. 영상증폭기에의한해부학적주요지표물들의분명한확인을위하여지름 1 mm 굵기의납선으로 (1) 근위대퇴골경부의둘레, (2) 대퇴전자부연결선 (cervico-trochanteric junction, intertrochanteric line), (3) 대전자부첨부 (greater trochanteric tip) 와전후면에서대퇴전자부의가장돌출된부위가지나도록경계면을표시하였다 (Fig. 1). 납선으로표시한대퇴골은영상증폭기를이용하여대퇴전후면과측면영상을촬영하였다. 이상적삽입구확인을위해사용된대퇴두부골수형금속정은아시아인의대퇴골에맞도록제작된제2형항회전근위대퇴정 (proximal femoral nail antirotation-ii, PFNA-II ; Fig. 1. A cadaveric adult femur that is marked with lead wires. To verify clearly through an image intensifier, the femur was marked with easily flexible lead wires on (1) the circumference of the femoral neck, (2) the cervico-trochanteric junction, and (3) the most protruded portions of anterior and posterior surfaces of the trochanter passing the tip of the greater trochanter. 174
The Determination of Optimal Entry Point for PFNA-II by Fluoroscopic Simulation Jin-Hoon Jeong and Gu-Hee Jung A B C d ** * * D E F Fig. 2. Image synthesis process on the anteroposterior (AP) plane with the image editing program. (A) An AP image of the femur, (B) an AP image of proximal femoral nail antirotation-ii (PFNA- II ), (C) synthesized images of the femur and the cephalomedullary nail on the ideal position, (D) drew a line bisecting the proximal part of PFNA-II, (E) checked the ideal entry point (*) of the nail on the femur, and removed the image of the nail, (F) measured the distance (d) between the ideal entry point (*) and the tip of the greater trochanter (**). 여 이 부위에서 경부의 전체 폭(width)과 전자부 전후면의 폭 이미지 합성을 통해 제2형 항회전 근위 대퇴정과 가상 고 을 측정하였다. 그리고 그 수평선과 이상적 위치로 가상 합성 정된 근위 대퇴 전후면 영상에 이상적 삽입구는 대전자부 된 대퇴정 근위부의 중앙점을 지나는 이분선이 교차하는 점 첨부를 기준으로 외측에 위치하는 예 없이 43예 모두 내측 의 위치를 표시하여 (1) 수평선 위에서 대퇴 경부의 전후 폭 에 위치하였으며, 첨부와의 거리는 평균 9.1 mm (범위, 7-15 의 길이와 경부 후방 피질골에서 교차점까지의 거리의 비와 mm)였다. 대퇴골 측면 영상과 가상 고정된 제2형 항회전 근 (2) 전자부 전후방 피질골 전체 폭의 길이와 후방 피질골에서 위 대퇴정의 합성 이미지에서 대퇴 경부 중앙점의 높이에서 교차점까지의 거리의 비를 백분율로 표시하였다(Fig. 3). 대퇴정 근위부의 중앙점은 대퇴 경부 후방 피질골을 기준 또한 합성된 전후면 영상에서 표시된 전자부 연결선과 이 상적 삽입점의 위치 관계를 확인하였다. 으로 대퇴 경부 전체 폭의 평균 0.30 (표준 편차, 0.01; 범위, 0.21-0.44)의 지점에 위치하였으며, 전자부 후방 피질골을 기 준으로 대퇴 전자부 전후 폭의 0.38 (표준편차, 0.04; 범위, 결 과 0.26-0.48) 지점에 위치하였다. 경부와 전자부 전후면의 중 심을 0.5로 산정하였을 때 전 예에서 중심보다 전방에 위치하 가상 합성된 이미지의 전 예에서 근위 대퇴골과의 충돌 없 는 예 없이 후방을 지남이 관찰되었다. 이 제2형 항회전 근위 대퇴정을 위치시킬 수 있었으며, 나선 또한 전후면 대퇴 영상과 제2형 항회전 근위 대퇴정의 합 형 칼날은 전후방 면에서는 대퇴 경부의 하방을 통과하여 대 성 이미지에서 납선으로 표시되어 촬영한 대퇴골의 전자부 퇴 골두 중앙에 모두 위치하였다. 연결선을 가상의 이상적 삽입점과 비교하였을 때 이상적 삽 175
Journal of the Korean Fracture Society Vol. 30, No. 4, October 2017 A B C D Fig. 3. Image synthesis process on the lateral plane with an image editing program. (A) A lateral image of the femur, (B) synthesized images of the femur and cephalomedullary nail on the ideal position, and drew a line bisecting the proximal part of proximal femoral nail antirotation-ii (PFNA-II ), (C) measured the width of the femoral neck and the distance between a posterior cortex of the femoral neck and the center of nail, (D) measured the width of the trochanter and the distance between a posterior cortex of the trochanter and the center of nail. 고찰 * Fig. 4. Ideal entry point (*) was at the extended line of the cervicotrochanteric junction. 입점의위치는전자부연결선의연장선상에위치함을알수있었다 (Fig. 4). 급격한고령화로인하여대퇴전자부골절을위한두부골수형금속정고정술은정형외과영역에서아주중요한부분을차지하고있다는점이널리공유되면서최대한만족스러운임상적결과를얻기위한많은연구들이발표되고있다. 18-23) 그중근위골편의최대고정력을얻고고정실패로인한합병증을방지하기위한두부골수형금속정의삽입을위해서는적절한삽입점의선택이매우중요한요소임이밝혀지고있다. 그리고최근들어체구가작은아시아인들에게적합한제2형항회전근위대퇴정이개발되고사용되면서이에대한임상적결과에대한연구들이발표되고있으나, 24,25) 해부학적인연구는거의없는실정이다. 이에저자들은체구가작은한국인의특성을고려하여한국인사체대퇴골과제2형항회전근위대퇴정을사진합성으로가상고정시대퇴정의이상적삽입점의위치를확인하고자하였으며, 실제적인수술에서의적용을위하여영상증폭기를통해확인하였다. 대퇴전자부골절의두부골수형금속정고정에있어이상적삽입점에대해서는많은연구들이보고되고있으나명확한이상적삽입점은합의가되지않았다. 8,26-35) 최근에는대 176
The Determination of Optimal Entry Point for PFNA-II by Fluoroscopic Simulation Jin-Hoon Jeong and Gu-Hee Jung 전자부첨부를기준으로내측에위치하는것을선호하고있으며, 8,15,36) 본연구에서도전예에서대전자부첨부를기준으로내측에위치하는것을다시한번확인할수있었다. 제 2형항회전근위대퇴정의경우이전의항회전근위대퇴정 (proximal femoral nail antirotation, PFNA ; DePuy Synthes) 을이용한대퇴전자부골절고정시발생하는외측피질골충돌 (lateral cortex impingement) 현상을방지하기위해대퇴정근위부의외측면을편평하게만들고내외측각도 (mediolateral angle) 를 6 o 에서 5 o 로줄였다. 그결과대전자부첨부에서근위대퇴정을삽입하였을때외측피질골충돌현상이발생하지않는다는보고도있으나, 16,37) Chon 등 36) 은최근 3차원컴퓨터단층촬영 (three-dimensional computed tomography, 3D CT) model을이용한연구에서대전자부첨부나외측으로삽입할경우제2형항회전근위대퇴정의경우에서도외측피질골충돌이발생할수있으며이상적인삽입점은대전자부첨부로부터평균 2.38 mm 내측에위치한다고하였다. 그리고 Tao 등 15) 은외측피질골충돌등의합병증을피하기위해대전자부첨부로부터 5 mm 내측으로삽입점을정하는것이좋다고하였다. 그러나본연구의전후면합성영상에서이상적삽입점의위치는첨부에서평균 9.1 mm 내측에위치하면서그범위는 7-15 mm로같은한국인사체대퇴골을대상으로한 Chon 등 36) 의연구결과인내측 2.38 mm보다상당히내측이었으며범위도좁지않았다. 이는 3D CT model을이용한기존의연구와는달리본연구는 2차원연구라는점에서실제대퇴경부의전방경사와시상면상에서근위대퇴골의형태변화를정확히반영할수없고영상편집프로그램을이용한가상고정을이용한연구라는점, 대퇴골수강넓이를고려하지않은단일한종류의금속정을사용하였다는점에서발생하였을것으로저자들은예상하였다. 하지만전예에서이상적인삽입점의위치가일괄적으로대전자부첨부의내측에위치하였다는점은유용한결과일것으로판단된다. 대퇴골전자부측면영상에서의이상적삽입구위치는많이알려져있지않으나너무전방으로위치할경우추가적인근위대퇴골골절을야기하게되므로주의가필요하게된다. 38,39) 본연구에서는전예에서명확하게이상적삽입점의위치가대퇴경부폭의중심과전자부전후방폭의중심을기준으로후방에모두위치하였으며후방피질골을기준으로대퇴경부의경우평균 30% (21%-44%), 전자부의경우평균 38% (26%-48%) 지점에금속정이위치하였다. 그러나실제수술시근위대퇴골은경부와전방경사가약 15 o 정도있 으며체간부와근접되어있고반대편다리에가려영상증폭기로정확한측면영상을얻을수없기때문에사면영상을이용하거나절개부위로손가락을넣어만져삽입점을후방으로위치시키는방법을많이사용하고있다. Grechenig 등 40) 은대전자부의 overhang 의차이에형태의변화가있으며이를이상와 (piriformis fossa) 위치관계에따라 4그룹으로분류하였다. 본연구에서는 2차원적인면에서대퇴골대전자부의형태분석만가능하여위방법으로분류를하는것은불가능하였으나한국인의사체대퇴골에서도 overhang 으로인한대전자부형태의다양한변화를관찰할수있었다. 이러한 overhang 의형태적다양성은실제수술시삽입점의선정에있어가장흔히사용되는기준인대전자부첨부의결정에있어혼동을야기할수있다. 그러나이러한형태의변화는 overhang 부위에서만관찰되며전자부연결선의연장선상부위에서는관찰되지않았다. 그리고본연구에서가상합성된이상적삽입구의위치는납선으로표시된전자부연결선과비교하였을때그연장선에위치한다는점을확인할수있었다. 따라서대전자첨부를기준으로이상적삽입구선정을할때는 overhang 형태의다양성에따라서삽입점의내측전위정도가변화될수있다는점을확인할수있었고이는한국인의대전자부의 overhang 에따른다양한형태의분류에대한연구가추가적으로필요할것으로생각된다. 또한이상적삽입구선정에있어영상증폭기하에전자부연결선의연장선을기준으로이상적삽입구를정하는것이또하나의기준이될수있을것이라고생각된다. 본연구는고령및골다공증에따른대퇴골수강확장과근위대퇴골의내반변형과같은변화들을고려하지않았다. 이러한점에서본연구결과가실제골다공증성전자부골절의치료에있어그유용성이제한적일수밖에없다. 또한실제수술시측면영상에서는대전자부가후방으로다소전위되는경우가많으나본연구에서는이러한골절자체의특성을고려하지않고골절이없는근위대퇴골에서의삽입점을연구하였다는점에서제한점이있다. 그리고사용된대퇴골이많지않아한국인에서의일반적특징으로해석하는데적지않은제한이있을것으로판단된다. 그러나본연구를통해기능적정복된전자부골절의두부골수형금속정고정술을위한삽입구선정에있어서대전자부첨부뿐만아니라전자부연결선을추가적인기준으로사용할수있다는것을확인할수있었으며, 전후면촬영에서는대전자부첨부보다외측으로치우친경우, 측면에서는대퇴경부중앙보다전방에위치하는경우는적절하지않은삽입구로판단할수있다는것 177
Journal of the Korean Fracture Society Vol. 30, No. 4, October 2017 을확인하였다는점에서유용할것으로예상된다. ORCID 결론 한국인사체의대퇴골을대상으로한두부골수형금속정이이상적인위치로고정되기위해서는전후방영상에서는대전자부첨부의내측에서삽입점이만들어져유도강선이삽입되어야하며, 삽입점을정하는다른기준으로수술중영상증폭기로촬영한전후면영상에서전자부연결선의연장선이유용할수있다. 또한측면영상에서는유도강선의삽입점은대퇴경부와대퇴전자부의정중선보다후방에위치하여야함을알수있다. 요약 목적 : 골다공증성대퇴전자부골절에서제2형항회전근위대퇴정을이용하여고정시이상적삽입점의위치를한국인사체대퇴골의형태를기반으로알아보고자한다. 대상및방법 : 골절및수술의흔적이없는 43개의사체대퇴골과제2형항회전근위대퇴정을영상증폭기로전후면과측면사진을촬영하였다. 그리고이미지합성프로그램을이용해촬영된영상이미지를합성하여이상적인삽입점의위치를전후면사진에서는대전자첨부, 전자간연결선과비교하여확인하였고측면영상에서는경부와전자부의전후폭과비교하여확인하였다. 결과 : 이상적삽입점은전후면영상에서대전자부첨부보다내측으로평균 9.1 mm ( 범위, 7-15 mm) 에위치하였다. 측면영상에서금속정의중심은경부의후방피질골을기준으로 30% 지점 ( 범위, 21%-44%), 전자부후방피질골을기준으로 38% 지점 ( 범위, 26%-48%) 에위치하였다. 또한이상적삽입점은대퇴전자부연결선의연장선상에위치하였다. 결론 : 제2형항회전근위대퇴정을이용하여대퇴전자부골절을고정시이상적삽입점은투시영상전후면영상에서대전자첨부의내측, 그리고측면영상에서대퇴경부와전자부의후방에위치하고있으며또한대퇴전자부연결선의연장선상에있음을알수있다. 색인단어 : 근위대퇴골, 전자부골절, 제2형항회전근위대퇴정, 삽입점, 이미지합성 정진훈, http://orcid.org/0000-0003-2731-1581 정구희, http://orcid.org/0000-0002-9751-4678 References 1. Cho HM, Lee K: Clinical and functional outcomes of treatment for type A1 intertrochanteric femoral fracture in elderly patients: comparison of dynamic hip screw and proximal femoral nail antirotation. Hip Pelvis, 28: 232-242, 2016. 2. Mavrogenis AF, Panagopoulos GN, Megaloikonomos PD, et al: Complications after hip nailing for fractures. Orthopedics, 39: e108-e116, 2016. 3. Aktselis I, Kokoroghiannis C, Fragkomichalos E, et al: Prospective randomised controlled trial of an intramedullary nail versus a sliding hip screw for intertrochanteric fractures of the femur. Int Orthop, 38: 155-161, 2014. 4. Niu E, Yang A, Harris AH, Bishop J: Which fixation device is preferred for surgical treatment of intertrochanteric hip fractures in the United States? A survey of orthopaedic surgeons. Clin Orthop Relat Res, 473: 3647-3655, 2015. 5. Tsukada S, Okumura G, Matsueda M: Postoperative stability on lateral radiographs in the surgical treatment of pertrochanteric hip fractures. Arch Orthop Trauma Surg, 132: 839-846, 2012. 6. Kozono N, Ikemura S, Yamashita A, Harada T, Watanabe T, Shirasawa K: Direct reduction may need to be considered to avoid postoperative subtype P in patients with an unstable trochanteric fracture: a retrospective study using a multivariate analysis. Arch Orthop Trauma Surg, 134: 1649-1654, 2014. 7. Oh JK, Hwang JH: Osteoporotic pertrochanteric fracture: IM nailing. J Korean Fract Soc, 22: 56-65, 2009. 8. Haidukewych GJ: Intertrochanteric fractures: ten tips to improve results. J Bone Joint Surg Am, 91: 712-719, 2009. 9. Bonnaire F, Zenker H, Lill C, Weber AT, Linke B: Treatment strategies for proximal femur fractures in osteoporotic patients. Osteoporos Int, 16 Suppl 2: S93-S102, 2005. 10. Zirngibl B, Biber R, Bail HJ: How to prevent cut-out and cutthrough in biaxial proximal femoral nails: is there anything beyond lag screw positioning and tip-apex distance? Int Orthop, 37: 1363-1368, 2013. 11. Miller SD, Burkart B, Damson E, Shrive N, Bray RC: The effect of the entry hole for an intramedullary nail on the strength of the proximal femur. J Bone Joint Surg Br, 75: 202-206, 1993. 12. Ostrum RF, Levy MS: Penetration of the distal femoral anterior cortex during intramedullary nailing for subtrochanteric fractures: a report of three cases. J Orthop Trauma, 19: 656-660, 2005. 13. Peña OR, Gómez Gélvez A, Espinosa KA: Clinical implications 178
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