대한정형외과학회지 : 제 39 권제 7 호 2004 J. of Korean Orthop. Assoc. 2004; 39: 804-11 대퇴골두연골하스트레스골절 송원석ㆍ김종원ㆍ유정준ㆍ구경회ㆍ윤강섭ㆍ김상림 ㆍ김영민ㆍ김희중 서울대학교의과대학정형외과학교실, 제주대학교의과대학정형외과학교실 목적 : 대퇴골두연골하스트레스골절 (subchondral stress fracture of the femoral head) 은드문질환으로서최근에주로부전골절 (insufficiency fracture) 의형태로발생한예들에대해보고되고있다. 본연구에서는부전골절및피로골절 (fatigue fracture) 형태로발생한스트레스골절환자의임상적, 방사선학적특징을평가하였다. 대상및방법 : 1998 년 1 월부터 2003 년 4 월사이에대퇴골두연골하스트레스골절로진단및치료받은 8 명 10 예를대상으로, 이들의임상적방사선학적소견에대해평균 33 개월추시결과를평가하였다. 결과 : 피로골절의양상으로는 6 명의젊고건강한군인에게서입대후 5 개월이내에발생하였고, 부전골절의양상으로는 1 명의노인과 1 명의골형성부전증환자에게발생하였다. 1 명을제외한모든환자에서대퇴골두무혈성괴사의위험요소및뚜렷한선행외상의과거력은있지않았다. 최초의단순방사선사진상 6 명 7 예에서이상소견이관찰되었다. 이중 4 예에서대퇴골두의함몰소견이관찰되었다. 골주사검사상대퇴골두에증가된흡수음영소견이관찰되었다. 자기공명촬영에서대퇴골두연골하이상신호선 (MR crescent sign) 과전반적인골수의부종소견이관찰되었다. 결론 : 대퇴골두연골하스트레스골절은부전골절및피로골절의양상으로모두나타날수있으며, 의심되는환자의경우골주사검사등을통하여조기진단함으로써대퇴골두의함몰을방지할수있을것이다. 색인단어 : 스트레스골절, 연골하골절, 대퇴골두 Subchondral Stress Fracture of the Femoral Head Won Seok Song, M.D., Jong Won Kim, M.D., Jeong Joon Yoo, M.D., Kyung-Hoi Koo, M.D., Kang Sup Yoon, M.D., Sang Rim Kim, M.D., Young-Min Kim, M.D., and Hee Joong Kim, M.D. Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul; Department of Orthopedic Surgery, Jeju National University, College of Medicine, Jeju, Korea Purpose: Subchondral stress fracture of the femoral head is a rare condition that usually occurs as an insufficiency fracture in people with poor bone quality. This study evaluated the clinical and radiographic aspects of the subchondral stress fracture of the femoral head that occurred in the form of an insufficiency or a fatigue fracture. Materials and Methods: Between January 1998 and April 2003, 10 cases of the subchondral stress fracture of the femoral head in 8 patients were treated. The characteristics of this condition were determined by assessing the clinical course and findings of the radiographs, bone scintigram and MR images. Results: A fatigue fracture developed in 6 young healthy conscripts within 5 months after recruitment. An insufficiency fracture developed in one senile patient and in one known osteogenesis imperfecta patient. All patients except for one did not have any predisposing factors for osteonecrosis and antecedent trauma. On the initial radiographs, femoral head collapse was observed in 4 hips. Bone scintigraphs showed increased radionuclide uptake in the femoral head. The MR images demonstrated an subchondral abnormal signal intensity line (MR crescent sign) and a bone marrow edema pattern. 통신저자 : 김희중서울시종로구연건동 28 서울대학교의과대학정형외과학교실 TEL: 02-2072-2970 FAX: 02-764-2718 E-mail: oskim@snu.ac.kr 본논문의요지는 2003년도대한정형외과학회추계학술대회에서발표되었음. 본연구는한국인체기초공학연구재단의 2002년도연구비 (KOHTERF-2002-05) 지원으로이루어진것임. Address reprint requests to Hee Joong Kim, M.D. Department of Orthopedic Surgery, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-774, Korea Tel: +82.2-2072-2970, Fax: +82.2-764-2718 E-mail: oskim@snu.ac.kr 804
대퇴골두연골하스트레스골절 805 Conclusion: A subchondral stress fracture of the femoral head can occur as a fatigue fracture as well as an insufficiency fracture. Bone scintigraphy is a valuable tool for screening patients suspected of having a subchondral stress fracture. Key Words: Stress fracture, Subchondral, Femoral head 스트레스골절은주로천골, 대퇴경부, 경골간부, 중족골등에빈번하게발생하는것으로알려져있다 7,9,10). Egol 등 3) 은젊은연령에서정상의골이반복적인과부하를받아생긴스트레스골절을피로골절 (fatigue fracture), 노령에서골다공증, 골연화증등으로인해약화된골이정상적인부하를받아생긴스트레스골절을부전골절 (insufficiency fracture) 이라정의한바있다. 대퇴골두연골하스트레스골절 (subchondral stress fracture of the femoral head) 은비교적드문질환으로최근에자기공명사진과이와비교한병리소견을바탕으로이에대한증례보고가발표되고있다 1,16,19,20,22). 그러나이들의대부분은노인환자나신장이식술을받은환자에있어서부전골절의양상으로발현한경우에국한되고있으며, 저자들이문헌고찰을통하여본바로는지금까지발표된연구중젊은군인들에게서발생한대퇴골두의스트레스성골병변 (stress osteopathy) 에대한논문이하나있을뿐이다 21). 본연구에서는부전골절및피로골절형태의대퇴골두연골하스트레스골절의임상적, 방사선학적특징을파악하고조기진단및감별진단의중요성에대해알아보고자하였다. 연구대상및방법 1998년 1월부터 2003년 4월사이에대퇴골두연골하스트레스골절로진단되어치료받은 8명의환자 10예를대상으로하였다 (Table 1). 이들은군입대후시행한신병훈련, 태권도훈련이나또는일상생활중심각한외상력없이고관절의통증이발생한예들로서, 임상적경과와단순방사선검사, 골주사 (bone scan) 검사및자기공명촬영 (MRI) 상골절선이확인되었고무혈성괴사의소견과는감별되는특징적소견을바탕으로진단하였고, 1명의환자에서는후향적으로그리고나머지환자의경우에서는전향적으로관찰하였다. 이들은남자가 7명여자가 1명으로, 통증발생시평균나이는 32세 ( 범위, 20-75) 였고, 평균신장은 171 cm ( 범위, 155-180 cm), 평균체중은 63 kg ( 범위, 47-78 kg) 이었다. 고관절통증은양측성인환자가 2명이었고, 일측성인환자가 6명으로일측성인경우우측이 4예, 좌측이 2예이었다. 단순방사선사진은환자들이고관절통증이있은후로부터 2주에서 6개월경과후촬영하였고, 전후면및측면방사선사진을얻었다. 골주사검사는 6명의환자에서시행하였다. 자기공명사진은다양한기기를사용하여촬영한 0.5-1.5T 범위의사진이었고, 영상기법은 Table 1. Patients data Patient Age (yr)/ No. Gender Ht (cm)/ Wt (kg) Previous event Case No. Side Time (mo) (x-ray) Initial x-ray finding Time (x-ray), time to initial x-ray after pain development; others, other MR images except -weighted image that show MR crescent sign; FS, fat suppressed; Gd, gadolinium enhanced; NWB, non weight bearing. Time (mo) (MRI) MR crescent sign others Duration Bone of sx scan (mo) 1 22/M 180/78 training 1 R 3 collapse 3 low, low THA 2 L 3 radiolucent line 3 low, low drilling 2 21/M 171/70 martial art 3 R 2 radiolucent line 5 - FS, high + 6 NWB 4 L 2 normal 5 low FS, high + 1.5 NWB 3 21/M 176/60 martial art 5 L 5 normal 5 low FS, low + 2 NWB 4 20/M 174/60 training 6 R 3 normal 3 low, low + 6 NWB 5 21/M 180/78 training 7 R 0.5 collapse 1 low Proton,low + bone graft 6 22/M 174/60 training 8 L 3 collapse 4 low, low 4 NWB 7 75/F 155/47-9 R 3 collapse 3 -, low + 4 NWB 8 52/M 158/53 heavy lift 10 R 6 osteoporosis 7 - Gd, high + drilling Tx
806 송원석ㆍ김종원ㆍ유정준외 5 인 - 강조영상, - 강조영상및프로톤강조영상등이사용되었다. 이들환자들에대하여평균 33개월 ( 범위, 6-68개월 ) 추시기간동안이들의임상증세의변화와이와연관하여단순방사선사진및자기공명사진을촬영하여변화를살펴보았다. 결과환자군 (Table 1) 을살펴보면, 1명의환자 ( 환자 7) 는특별한기저질환이없는비교적건강한 75세의노인환자로특별한수상의과거력없이통증이발생하였고, 1명 의환자 ( 환자 8) 는 52세의 Sillence type Ⅳ의골형성부전증 (osteogenesis imperfecta) 환자로서 30대이후로는골절의병력은존재하지않았으며무거운짐을나르는일을한뒤통증이발생하였고 4년전에도비슷한양상의통증이있었으나수개월경과후자연적으로호전된과거력이있었다. 나머지 6명의환자는모두 20대초반의건장한남자로서신병훈련또는태권도훈련도중발생한고관절통증을주소로군병원에서대퇴골두무혈성괴사의진단후전역조치를받은환자들이었다. 골형성부전증환자 1명의경우음주의과거력이있었으나나머지환자들에서는음주나부신피질호르몬투여등 A B C Fig. 1. Patient 1, cases 1 and 2. A 22-year-old man with bilateral hip pain. (A) AP and frogleg radiographs obtained three months after pain show that the right femoral head had collapsed. In the left femoral head, there is a radiolucent line (arrowhead). (B) AP and frogleg (postoperative) radiographs obtained seven months after pain shows healing of the subchondral fracture with slight progression of the collapse in the left femoral head. (C) and -weighted MR images (top) obtained at about the same time show a diffuse area of low signal intensity on the image, which converted to iso/high signal intensity on images (asterisk, bone marrow edema pattern). Linear low signal intensity bands (arrowhead, MR crescent sign) in subchondral area are shown on both images. Coronal and -weighted MR images (bottom) obtained seven months after the onset of pain show the resolution of abnormal signal intensity changes and the disappearance of the MR crescent sign.
대퇴골두연골하스트레스골절 807 의대퇴골두무혈성괴사의위험요소는존재하지않았다. 6명의환자 7예에서, 최초단순방사선사진상뚜렷한이상을보였다. 이중 4예에서는대퇴골두의전상방에붕괴소견이관찰되었고 (Fig. 1), 2예에서는방사선투과성선 (radiolucent line) 이, 1예에서는골다공증소견이관찰되었다. 나머지 3예에서는최초단순방사선사진에서뚜렷한이상소견은보이지않았다 (Fig. 2). 시행된골주사검사에서는모두대퇴골두에증가된흡수음영이관찰되었다. 최초의자기공명촬영은환자에따라통증발생후 1 개월에서 7개월사이에시행되었다. 병변은 1명 ( 환자 2) 2예의경우에서만대퇴골두의후상방에존재하였고, 나머지예에서는모두대퇴골두의전상방에존재하였다. 자기공명사진상공통적으로 - 강조영상에서경계가불명확한부분적또는광범위한저신호강도 (low signal intensity) 소견이나타났으며, 이들은 -강조영상또는지방억제영상 (fat suppressed image) 에서고신호강도 (high signal intensity) 로전환되었다 ( 골수부종양상, bone marrow edema pattern). 또한모든예에서연골하골판 (subchondral plate) 에평행하게주행하는불규칙한모양의이상신호강도선 ( 연골하골절선, MR crescent sign) 10,11) 이관찰되었다 (Fig. 1-4). A Fig. 2. Patient 4, case 6. A 20-year-old man with right hip pain. (A) AP and lateral radiographs obtained three months after pain show no definite abnormality. Bone scan in the inset shows increased radionuclide uptake in the right femoral head. (B) and -weighted MR images (top) show bone marrow edema pattern on the femoral head and neck area (asterisk). Fracture line (arrowhead) in the subchondral area is shown. and fat suppressed -weighted images (bottom) obtained fourteen months after the onset of pain show the resolution of abnormal signal intensity changes. FS B A B Fig. 3. Patient 7, case 9. A 75-year-old woman with right hip pain. (A) AP and frogleg radiographs obtained three months after pain show slight collapse of the femoral head (arrowhead). (B) and -weighted axial MR images show bone marrow edema pattern (asterisk) with fracture line (arrowhead).
808 송원석ㆍ김종원ㆍ유정준외 5 인 이러한이상신호강도선은 7예에서는 - 강조영상에서저신호강도의소견으로관찰되었고다른강조영상에서는다양한신호강도로나타났다. 나머지 3예에서는각각가돌리늄 (gadolinium) 조영 -강조영상, 지방억제 - 강조영상과, - 강조영상에서만연골하골절선이관찰되었다 (Fig. 3). 모든환자들에대해서처음에는비체중부하의보존적 치료를시행하였다. 대퇴골두의붕괴소견이심하지않고보존적치료를시행한 6예에서는통증이점차완화되었고, 6개월뒤에는모두소실되었으며추시자기공명사진을시행한예에서 ( 증례 1-6) 이와상응하여이상소견이정상화되었다. 이들의평균통증지속기간은 4개월 ( 범위, 1.5-6개월 ) 이었다. 다발성천공술 (multiple drilling) 을시행한 2예의경우는모두시술후 2개월경과 A Proton B C D Fig. 4. Patient 5, case 7. A 21-year-old man with right hip pain. (A) AP and frogleg radiographs obtained six weeks after pain show collapse of the right femoral head. Bone scan in the inset shows increased radionuclide uptake in the right femoral head. (B) -weighted and proton MR images show a diffuse area of signal intensity changes (asterisk) on the right femoral head and neck with fracture line (arrowhead). Slight signal intensity changes (asterisk) are shown on the left femoral head without subchondral fracture line. (C) Photographs during operation (left) show flattening of the femoral head and restoration of the contour by strut bone graft impaction (arrowhead) through a cortical window (right). Photomicrograph in the inset (Stain, H&E; magnification, 100) obtained from the subchondral area shows E no evidence of necrosis. (D) Eighteen months follow up radiographs show no progression of collapse. (E) -weighted coronal MR image obtained twenty months after the onset of pain shows the resolution of abnormal signal intensity changes including the fracture line.
대퇴골두연골하스트레스골절 809 Fig. 5. A typical case of osteonecrosis of the femoral head (ONFH). Subchondral fracture (arrowhead) occurs inside the necrotic portion surrounded by a reactive line of an abnormal signal intensity (arrows). The bone marrow edema pattern (asterisk) is only shown outside the necrotic area. 후통증의소실을나타냈다. 대퇴골두의붕괴가심하였던 2예의경우에대해서는각각인공고관절전치환술과지주골이식술 (strut bone graft) 을시행하였다. 인공고관절전치환술을시행한환자 ( 환자 1) 는통증발생후 5개월이경과하여본정형외과를방문하였다. 이환자는최초대퇴골두무혈성괴사로진단하여골두붕괴가심한우측에는인공고관절전치환술을, 붕괴가없는좌측에는다발성천공술을시행하였다. 또지주골이식술을시행한환자 ( 환자 5) 는통증발생후 6주만에방문하였고, 최초단순방사선사진과비교하여붕괴가진행되는소견을보였다. 이환자에대해장골에서채취한지주골을대퇴경부에창을내어삽입함으로써대퇴골두의함몰을다시펼수있었고, 추시사진상더이상의함몰은관찰되지않았다. 수술시얻은연골하골부위의망상골조각 (cancellous bone chips) 의조직검사에서무혈성괴사의소견은관찰되지않았다 (Fig. 4). 고찰 1972년 Todd 등 18) 이대퇴골두골소주 (trabecular) 만의피로골절을보고한이후, 대퇴골두연골하골의스트레스골절에대한몇몇보고 1,2,16,20,22,23) 가있었으나이들대부분은부전골절의양상으로발생한예만을포함하고있다. 본연구에서는부전골절의양상으로발생한 2예 ( 노인환자및골형성부전증환자 ) 뿐만아니라, 20대의젊은군인에게서발생한피로골절양상의스트레스 골절을포함하고있다. 연구대상환자들에대한진단은기본적으로일련의자기공명사진을바탕으로하였다. 최초자기공명사진상골절선 (fracture line) 및골절선주변의골수부종양상 (bone marrow edema pattern) 소견을관찰할수있었으며, 이러한소견은추시사진상소실되었다. 그러나이러한골절선은모든영상에서관찰되지는않았으며일부절단면에서만관찰할수있었다. 일찍이 Visuri 21) 는자기공명사진상의가역적인골수부종소견을바탕으로 10 명의군인에서발생한대퇴골두의스트레스성골병변에대해기술한바있는데, 이는대퇴골두연골하골의스트레스골절이젊고건강한사람에게서피로골절의형태로도발생할수있음을시사하는것으로, 만약좀더해상도가좋은자기공명사진을이용하였더라면골절선을발견하였을가능성이있다. 골수부종양상은고관절의일과성골다공증 (transient osteoporosis of the hip) 의특징적인자기공명사진소견이다. 일과성골다공증의원인에대해서는아직명확하게밝혀지지않았으나대퇴골두연골하골절이그원인중하나일것이라는보고도있다 5,15). 본연구의경우에있어서도 4예의경우초기단순방사선촬영상뚜렷한골절등의이상소견이관찰되지않았으며시간이경과됨에따라증세가소실되는것을관찰할수있었다. 만약이들의경우에자기공명촬영에서골절선을확인하지못하였더라면고관절의일과성골다공증으로진단되었을것이다. 또한 Miyanishi 등 13) 은고관절의일과성골다공증으로진단하였던 12예의후향적연구에서, 자기공명사진상연골하골절선을확인할수있었다고보고하였다. 이러한연골하골절선은자기공명사진의일부절단면에서만확인할수있으므로, 일과성골다공증으로진단하기위해서는여러절단면에서다양한신호강도로얻은자기공명영상을세심히관찰하여골절선이없음이확인되어야할것이다. 대퇴골두의연골하골절및골수부종양상은대퇴골두무혈성괴사의경우에있어서도관찰되므로스트레스골절과의감별이용이하지않을수있다. 본연구의환자의경우도젊은군인의경우에는모두대퇴골두무혈성괴사로전역조치를받고방문하였고, 첫째환자의경우에는본병원에서도최초에대퇴골두무혈성괴사로진단후치료하였던경우로후향적으로본연구의대상으
810 송원석ㆍ김종원ㆍ유정준외 5 인 로포함되었다. 대퇴골두무혈성괴사의경우, 괴사가발생되면우선괴사부위의외연을따라재생과정이진행되어소위반응영역 (reactive zone) 이형성되는데이는괴사부위측의혈관이풍부한육아조직과그외측의신생골형성부위로이루어지며, 자기공명사진상 - 강조영상에서저신호강도의띠 (low signal intensity band), - 강조영상에서는 double line sign으로나타난다 8,14,17). 이와같은괴사부외연의이상신호강도띠는무혈성괴사시가장먼저나타나는자기공명영상소견이다. 무혈성괴사시연골하골절은재생과정이어느정도진행한후괴사부의내부에발생하기때문에 4,6) 자기공명사진상연골하골절선바깥쪽으로반응영역인이상신호강도띠가존재하며, 골수부종소견도괴사부바깥쪽에서만관찰된다 (Fig. 5). 그러나대퇴골두의연골하골절의경우에는대퇴골두무혈성괴사에서보이는저신호강도의띠, 즉괴사골주변의반응영역이관찰되지않으며, 또한골수부종양상이골절선인접부위까지나타난다 19). 본연구대상자중 6예에있어서단순히체중부하보행만을억제하여통증은시간이경과함에따라호전되었고, 이와더불어추시자기공명사진상이상신호소견이소실되었다. 이러한시간경과에따른임상적, 방사선학적호전소견은대퇴골두스트레스골절의특징적인소견으로보고되고있다 14,16,20). 그러나본연구의 2예및다른보고의경우에나타나듯이대퇴골두연골하스트레스골절은골두의붕괴를초래하여수술적치료를필요로할수있다. 대퇴골두연골하스트레스골절을고관절통증의한원인으로서인식하는것은다른질환과의감별진단및발병후추가적인손상 ( 골두함몰 ) 을피할수있다는점에서중요하다고판단된다. 따라서부전골절및피로골절을포함한스트레스골절이대퇴골두에도발생할수있다는것을염두에두고, 고관절부위의통증을호소하는환자에대한감별진단의하나로고려하여야할것이다. 특히골주사검사는의심이가는환자의선별검사로서큰도움이될것으로생각된다. 결론대퇴골두연골하골의스트레스골절은부전골절및피로골절의양상으로나타날수있으며, 조기진단및감 별진단이치료및예후의측면에서매우중요할것으로판단된다. 참고문헌 1. Bangil M, Soubrier M, Dubost JJ, et al: Subchondral insufficiency fracture of the femoral head. Rev Rhum Engl Ed, 63: 859-861, 1996. 2. Buttaro M, Gonzalez Della Valle A, Morandi A, Sabas M, Pietrani M and Piccaluga F: Insufficiency subchondral fracture of the femoral head. Report of 4 cases and review of the literature. J Arthroplasty, 18: 377-382, 2003. 3. Egol KA, Koval KJ, Kummer F and Frankel VH: Stress fractures of the femoral neck. Clin Orthop, 348: 72-78, 1998. 4. Glimcher MJ and Kenzora JE: The biology of osteonecrosis of the human femoral head and its clinical implications. Ⅲ. Discussion of the etiology and genesis of the pathological sequelae. comments on treatment. Clin Orthop, 140: 273-312, 1979. 5. Karagkevrekis CB and Ainscow DA: Transient osteoporosis of the hip associated with osteogenesis imperfecta. J Bone Joint Surg, 80-B: 54-55, 1998. 6. Kim YM, Oh HC and Kim HJ: The pattern of bone marrow oedema on MRI in osteonecrosis of the femoral head. J Bone Joint Surg, 82-B: 837-841, 2000. 7. Kiuru MJ, Pihlajamaki HK and Hovuo JA: Fatigue stress injuries of the pelvic bones and proximal femur. Evaluation with MR imaging. Eur Radiol, 13: 605-611, 2003. 8. Kubo T, Yamazoe S, Sugano N, et al: Initial MRI findings of non traumatic osteonecrosis of the femoral head in renal allograft recipients. Magn Reson Imaging, 5: 1017-1023, 1997. 9. Lassus J, Tulikoura I, Konttinen YT, Salo J and Santavirta S: Bone stress injuries of the lower extremity. a review. Acta Orthop Scand, 73: 359-368, 2002. 10. Maitra RS and Johnson DL: Stress fractures. Clinical history and physical examination. Clin Sports Med, 16: 259-274, 1997. 11. Mitchell DG, Joseph PM, Fallon M, et al: Chemical-shift MR imaging of the femoral head: An in vitro study of normal hips and hips with avascular necrosis. Am J Roentgenol, 148: 1159-1164, 1987. 12. Mitchell DG, Rao VM, Dalinka MK, et al: Femoral head avascular necrosis: Correlation of MR imaging, radiographic staging,
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