대한고관절학회지제 19 권제 3 호 Vol. 19, No. 3, September, 2007 고관절전치환술시비구컵의정렬측정을위한수술중방사선촬영 가톨릭대학교의과대학대전성모병원정형외과학교실 목적 : 고관절전치환술시행시비구컵의적절한정렬여부를보기위한수술중 C형투시장치를이용한방사선촬영의시행및그유효성을평가하고자한다. 대상및방법 : 2004년 3월부터 2007년 4월까지고관절전치환술시행받은환자중 54명의수술중방사선촬영을시행한군을대상으로하였으며, 적절한정렬여부에대한비교항목으로수술후방사선상비구컵의정렬측정및고관절탈구가일어나는빈도를조사하여독립표본 t-검증을시행하였다. 결과 : 조사대상환자중에서고관절탈구가일어난경우가1예발생하였으며수술후방사선상비구컵의경사각은평균 39.9, 표준편차 3.038이었다. 전향각은평균 14.9, 표준편차 1.398이었다. 평균차검정및분산에대한동질성검정결과경사각에서는분산에대한동질성검정에서만유의미한소견을보였지만전향각에서는평균차검정및분산에대한동질성검정모두에서유의미한소견을보였다.(P<0.05) 결론 : 고관절전치환수술중시행하는방사선촬영은비구컵정렬의정확도를높여주고삽입물의안정성에도움을주는것으로사료된다. 색인단어 : 고관절전치환술, 비구컵, 정렬 서 인공고관절전치환술시행받은환자의임상적으로가장중요한수술후문제는인공고관절삽입물의탈구일것이다 1,4,13). 그것은대략인공고관절전치환술을시행받은환자의 0.5% 에서 10% 까지발생하는것으로보고되고있으며그수치는줄어들지않고있는실정이다 2,3,7). 이제까지인공고관절전치환술시행후탈구를예방하기위해서여러요소를연구한결과가장중요한요소로밝혀진것이인공삽입물의정렬, 즉적절한전향각과경사각을맞추어삽입물을고정시키는지가가장중요한요점이라고알려져있다 13). 또탈구외에세라믹대세라믹관절면의라이너외측연에서발생하는세라믹비구변연부골절을예방 론 하기위해정확한삽입물의정렬을얻을수있는항법장치까지권유되는실정이다 5,11). 그러나이러한수술은고가의장비가필요하게되어실제적으로이용하는데어려움이있다. 저자들은수술시행중에인공삽입물을가장적절한위치에고정시키기위해정렬안내기를이용하여일단삽입물을고정시킨후, 예전부터사용하고있던 C 형투시장치를이용하여인공삽입물의적절한정렬을확인하는방법을사용하였으며이러한방법을사용하여인공고관절전치환술을시행한군에서수술후단순방사선촬영상에서의인공삽입물의정렬및추후탈구발생여부를조사하여수술중 C 형투시장치촬영의임상적유용성을분석하고문헌고찰과함께보고한다. 대상및방법 통신저자 : 김원유대전광역시중구대흥동 520-2 가톨릭대학교의과대학대전성모병원정형외과 TEL: 82-42-220-9530 FAX: 82-42-221-0429 E-mail: weonkim@hotmail.com 본논문은 2007 년가톨릭중앙의료원의연구보조비지원을받아이루어졌음. 1. 연구대상및방법 2004 년 3 월부터 2007 년 4 월까지측와위에서후외측도달법으로고관절전치환술을시행받은환자중 54 명의수술실내방사선촬영을시행한군을대상으로하였다. 평균나이는 58.4 세이었고나이범위 29~88 세였다. 술전진단은대퇴골두골괴사가 35 명, 퇴행성고관절염이 10 명이었다. 그리고대퇴골경부골절이 7 명이었고류마티스 155
관절염은 2 명이었다. 인공삽입물은 C2 스템 (Lima-Lto) 을사용하였으며샌드위치형태의세라믹라이너를사용하였다. 모든환자에대해서는인공고관절전치환술시행중 Lewinnek 등이제시한비구컵의안전한정렬 ( 경사각 :40±10, 전향각 :15±10 ) 의중간값인경사각 40, 전향각 15 를이상적인정렬로정한후 13), 비구측삽입물을정열안내기를사용하여비구컵을고정한이후 C 형투시장치로확인하는작업을거쳤다 (Fig. 1). 술전단순방사선사진상비구이형성이없는정상적비구일경우비구연을따라비구컵을삽입하고나사못을고정후최종적인정렬을 C 형투시장치로확인하였다 (Fig. 2). 또한술전방사선사진상비구이형성증이심한환자일경우에는바른정렬에맞게 Trial 을삽입후일단 C 형투시장치로확인하였고만족스럽지않을경우 Trial 을다시삽입후 C 형투시장치로재확인하는작업을시행하였다 (Fig. 3). 각환자는수술후다음날고관절전후면방사선사진을촬영하여계측에이용하였다. 방사선사진은모두동일한장소에서촬영하였으며전후방사진은가능한일정배율을유지하도록하였다. 2. 측정방법 측정시마다의오차를최소화하기위해동일한사진에대해두명의정형외과전문의가측정하여두수치의평균치를한개의측정치로삼았다. 단순전후면방사선사진에서평면전향각을측정하기위해여러방법이고안되었지만본연구에서는 Boardman 의방법을이용하여비구삽입물하방에투영되는타원의단경을이용하였다 (Fig. 4). Boardman 은크기 44 mm 에서 64 mm 이내의반구형컵에서전향각이 0 도에서 25 도이내일경우 15% 에서 20% 사이로확대된전후면사진의컵하부타원의단경을 mm 로측정하면그절대값이방사선학적비구전향각을나타내는것을관찰하였으며그오차는 5 도를넘지않는다고하였다 6). 3. 통계적분석 Fig. 1. The photograph of intraoperative C-arm fluoroscopy imaging technique, we can achieve proper alignment of acetabular cup more easy by using the technique. 이상적인정렬위치 ( 경사각 40, 전향각 15 ) 를기준으로통계적분석으로평균분석을시행하였으며참값과의 A B Fig. 2. The intraoperative C-arm technique can be used after fixation of true acetabular cup. Because X-ray shows over inclination angle of acetabular cup (A)., we removed screws and cup out, then refixed it properly (B). 156
고관절전치환술시비구컵의정렬측정을위한수술중방사선촬영 A B C Fig. 3. A case of total hip replacement arthroplasty due to severe dysplasia, we could use C-arm fluoroscopy after inserting trial, threre seemed over inclination angle of acetabular cup (A), so we refixed it, which seemed proper anteversion and inclination angle (B). Finally we fixed true acetabular cup at proper angle (C). 결 과 수술후추시상인공삽입물의탈구가일어난경우가현재까지 1 예가발생하였다. 수술후단순전후면방사선상비구측삽입물의경사각이평균 39.9 ( 범위 : 33.9~45.7 ), 표준편차 3.038 이었다. 전향각은평균 14.9 ( 범위 : 12.5~18.2 ), 표준편차 1.398 이었다 (Fig. 5A, B). 평균차검정에서전향각은유의확률이 p=0.000 으로 0.05 보다작으므로의미있는결과가있다고할수있었다. 분산의동질성검정에서도유의확률 p=0.000 으로의미있는값이도출되었다. 전향각의평균은 14.9 로이상적인각도 15 와거의일치한것으로나타났다. 경사각은유의확률이 0.312 로 0.05 보다크므로의미있는값은아니었다. 그러나경사각의분산에대한동질성검정에서는유의확률 p=0.034 로 0.05 보다작으므로경사각에서도높은정확도를보여준다고할수있었다. 고 찰 Fig.4. Boardman s direct measurement in AP model. The longest perpendicular distance D in mm nearly represents the planar anteversion angle. 오차에대한분산분석도동시에시행하였다. 계측치사이의차이를알아보기위해분산분석과독립표본 T- 검정을시행하였다. 모든통계분석은 SPSS (version 11.0. Chicago, USA) 를이용하였다. 이제까지일반적으로고관절전치환술후의방사선학적평가는주로삽입물의안정성이나주변골의반응, 골용해의여부등에초점이맞추어져온경우가많았다 7,8). 그러나삽입물의위치를측정하는방법에대한연구는최근들어임상적으로수술후에단순방사선촬영을이용하여전향각과경사각을측정하는방법이소개되고있다 3,6,7,9,12). 이방법들에따라보통전향각은 5 에서 25, 경사각은 30 에서 50 정도가가장수술후탈구를예방하는안전한정렬이며이범위를넘어가게되면탈구의빈도가약 4 배로증가한다고밝혀졌다 13,17). 이러한인공삽입물을적절한정렬위치에맞춰고정시키기위해일반적으로인공고관절전치환술시행중에정렬안내기를이용하여인공삽입물의정렬을맞추는방법을주로사용하고있으나이것 157
은수술대에누워있는환자의위치에따라실수가나올가능성이많은것이사실이다 10,12,16). 또한 Archbold 등이기술한수술시야에서의비구인대방향, 비구연의시각적참고등의수술시의경험적측면을 동원하여비구측삽입물의적절한전향각과경사각을맞추는것이어느정도가능하다고할지라도전체적으로인공고관절치환술을시행받은환자의 42% 정도는수술후촬영한고관절전후면사진상에서안전한위치에서벋어 Fig. 5. (A) The inclination angle of acetabular component at plain AP image was average 39.9 (range: 33.9~45.7 ) and standard deviation 3.038. (B) The anteversion angle of acetabular component was average 14.9 (range: 12.5~18.2 ) and standard deviation 1.398. 158
고관절전치환술시비구컵의정렬측정을위한수술중방사선촬영 나고정되어있는경우가많다 4). 특히전향각과경사각을각각비교해볼경우수술시행받은환자의 60% 까지안전한위치에서벋어나비구측삽입물이고정된다고알려져있다 13,18,19,20). 이러한오류가발생하는이유는수술시거의모든환자가수술대위에서측와위로누워서시행받는경우가많기때문에수술중환자가전면또는후면으로기울어지는경우가흔히발생하여수술중에경사각을안전한위치에제대로맞추기에어려움이있기때문이다 10,14,21). 이러한이유로보다적절한전향각을맞추려는시도가필요한것이다. 따라서인공고관절삽입물의위치의적절성을확인하는방법으로수술후단순방사선사진으로확인하는것이가장보편적이라는점을감안하여수술중에비구측삽입물을고정후에바로 C 형투시장치를이용하여정확한전후방사선사진촬영하여전향각과경사각을계측한다면삽입물이안전한위치에서벗어나만족스럽지못하게고정되더라도바로비구측삽입물을재고정시키면된다. 만약, 환자가정확한측와위에서약간기울어져위치할경우 C 형투시장치를조정하여폐쇄공 (obturator foramen) 의크기를동일하게만들고치골결합부를수직으로보이도록조정후고관절을정면에서투시하면 C 형투시장치촬영시매우정확한고관절전후면촬영을시행할수있어삽입물의정렬을효과적으로확인할수있다. 또한수술중 C 형투시장치를사용하는데따른외부감염을우려할수있겠고 1 예의감염이있었으나이는신부전증환자의환자의기저질환의영향으로생각되며비구이형성이심한환자의수술시 C 형투시장치를여러번사용하더라도현재까지삽입물의외부감염은발생한사례가없었던것으로보아이에따른감염의위험은없을것으로사료된다. C 형투시장치를수술중에사용한다면오직술자의경험과정렬안내기에의존하여비구측삽입물의전향각과경사각을짐작하여고정하는것보다정확도를높일수있다. 또한, 비교적길지않은시간과간편한조작으로인공삽입물의정확한정렬을가능하게하여수술후인공고관절삽입물의탈구라는큰위험의가능성을낮출수있어환자의수술후재활에도도움을줄수있고, 삽입물이정확한정렬에위치함으로써인공관절삽입물의영구성이보장될수있을것으로판단된다. 결 인공고관절전치환술이후에인공삽입물의탈구를야기하는가장중요한수술적요소인삽입물의정렬의정확성을높이기위한방법으로수술중에 C 형투시장치를이용한다면술자가의도하는대로정확한전향각과경사각을획득할수있다. 이방법은간편하며쉽게적용가능하고수술중에삽입물의적절한정렬을방해하는환자의전면또 론 는후면으로기울어지는현상등과는상관없이적절한정렬을얻을수있기때문에더욱효과적이라고생각된다. REFERENCES 01) Ackland MK, Bourne WB and Uhthoff HK: Anteversion of the acetabular cup: measurement of angle after total hip replacement. J Bone Joint Surg. 68-B:409-413, 1986. 02) Alil Khan MA, Brakenbury PH and Reynolds ISR: Dislocation following total hip replacement. J Bone Joint Surg. 63-B:214-218, 1981. 03) Anda S and Admal IK: Simple mathematical relations between the acetabular anteversion and sector angles. Acta Radiologica, 34:99-100,1993. 04) Archbold HAP, Mockford B, Molloy D, McConway J, Ogonda L and Beverland D: The transverse acetabular ligament: an aid to orientation of the acetabular component during primary total hip replacement. J bone Joint Surg. 88-B: 883-886, 2006. 05) Belei P, Skwara A, De La Fuente M, Schkommodau E: Fluoroscopic navigation system for hip surface replacement. Comput Aided Surg, 12(3): 160-167, 2007. 06) Boardman DL: A simple and reliable method of estimating radiographic acetabular anteversion. 68th Annual Meeting prceedings of American Academy of Orthopedic Surgeons: 497, 2001. 07) Engh CA, Massin P and Suthers KE: Roentgenographic assessment of the biologic fixation of porous-surfaced femoral components. Clin Orthop, 257: 107-128, 1990. 08) Etienne A, Cupic Z and Charnley J: Postoperative dislocation after Charnley low-friction arthroplasty. Clin Orthop, 132: 19-23, 1978. 09) Fabek L, Farrokh D, Tolley M, Deschamps PY, Gebhart M and Deline P: A method to measure acetabular cup anteversion after total hip replacement. Acta orthopedica Belgica, 65: 485-491,1999. 10) Hassan DM, Johanston GHF, Dust WNC, Watson G and Dolovich AT: Accuracy of intraoperative assessment of acetabular prosthesis placement. J arthroplasty, 13: 80-84, 1998. 11) Hess T, Gampe T, Kottgen C, Szawlowski B: Intraoperative navigation for hip resurfacing: method and first results. Othop, 33(10): 1183-1193, 2004. 12) Jolles BM, Zangger P and Leyvraz P:Factors predisposing to dislocation after primary total hip arthroplasty: a multivariate analysis. J arthroplasty, 17: 282-288, 2002. 13) Lewinnek GE, Lewis JL, Tarr R, Compere CL and Zimmerman JR: Dislocations after total hip replacement arthroplasties. J Bone Joint Surg, 60-A: 217-220,1978 14) Murray DW: The definition and measurement of acetabular orientation. J Bone Joint Surg, 75-B: 228-232, 1993. 159
15) Pradhan R: Planar anteversion of the acetabular cup as determined from plain anteroposterior radiographs. J Bone Joint Surg, 81-B: 431-435, 1999. 16) Ritter MA: Dislocation and subluxation of the total hip replacement. Clin Orthop, 121: 92-94, 1976. 17) Saxler G, Marx A, Vandevelde D, Langlotz U: The accuracy of free-hand cup positioning: a CT based measurement of cup placement in 105 total hip arthroplasties. Int Orthop, 28: 198-201, 2004. 18) Schneifer R, Freiberger RH, Ghelman B and Ranawat CS: Radiologic evaluation of pain and joint prosthesis. Clin Orthop, 170: 156-168, 1982. 19) Visser JD and Konings JG: A new method for measuring angles after total hip arthroplasty: a study of the acetabular cup and femoral component. J Bone Joint Surg, 63-B: 556-559,1981. 20) Woo RY and Morrey BF: Dislocations after total hip arthroplasty. J Bone Joint Surg, 82-A: 1295-1306,1982. 21) Yao L, Yao J and Gold RH: Measurement of acetabular anteversion on the axiolateral radiograph. Clin Orthop, 316: 106-111, 1995. ABSTRACT Intraoperative Imaging to Monitor the Alignment of Acetabular Cup for Total Hip Replacement Arthroplasty Sang-Eun Park, M.D., Weon-Yoo Kim, M.D., Oh-Soo Kwon, M.D., Young-Yul Kim, M.D., Ho-Yeoun Won, M.D. Department of Orthopaedic Surgery, Daejeon St. Mary s Hospital, The Catholic University, Daejeon, Korea Purpose: This study examined intraoperative imaging to monitor the alignment of the acetabular cup for total hip replacement arthroplasty (THRA) using C-arm fluoroscopy and to increase the accuracy of THRA prosthetic fixation. Materials and Methods: From March 2004 to April 2007, 54 patients underwent THRA monitored by the imaging. 40 inclination and a 15 anteversion angle was considered to be ideal. The items compared included the alignment of the acetabular cup and the follow up rates of the hip dislocation. Results: There was one case of hip dislocation. The mean inclination angle of the acetabular component was 39.9 with a standard deviation of 3.038. The mean anteversion angle of the acetabular component was 14.9 with a standard deviation of 1.398. The mean difference examination and variance in the anteversion angle showed a significant result. (P<0.05) Conclusion: Intraoperative imaging increases the alignment accuracy of the acetabular cup and helps stabilize the prosthesis. Key Words: Total hip replacement arthroplasty, Acetabular cup, Alignment 160