PSJHJOBM! BSUJDMF 대한족부족관절학회지 : 제 15 권제 4 호 2011 J Korean Foot Ankle Soc. Vol. 15. No. 4. pp.212-216, 2011 인하대학교의학전문대학원정형외과학교실 Diagnosing Symptomatic Accessory Tarsal Bones Using SPECT/CT Ryuh Sup Kim, M.D., Joon Soon Kang, M.D., Young Tae Kim, M.D., Bom Soo Kim, M.D. Department of Orthopaedic Surgery, Inha University College of Medicine, Incheon, Korea =Abstract= Purpose: This study was designed to analyze the usefulness of Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) in diagnosing symptomatic accessory tarsal bones. Materials and Methods: Twenty four feet (16 patients) with symptomatic accessory navicular and/or os trigonum, who agreed to take SPECT/CT, were included in this study. Fifteen feet had accessory navicular, five had os trigonum, and four had both. According to the uptake in the SPECT/CT, 11 feet were classified into high and 13 into low uptake groups. The low uptake group was treated non-operatively, while the high uptake group received operations when initial conservative management failed. A modified Kidner procedure was performed for accessory navicular and arthroscopic excision was done for os trigonum. After a mean follow-up of 6.8 (range, 3~13) months, the American Orthopaedic Foot and Ankle Society (AOFAS) score and the Visual Analogue Scale (VAS) for pain were compared. Results: Patients in the high uptake group had a higher initial mean VAS score (7.0±0.8 vs 2.2±0.9, p<0.05) and a lower initial mean AOFAS score (45.9±9.2 vs 83.9±4.2, p<0.05) compared to the low uptake group. All patients in the low uptake group improved after non-operative treatment. Seven patients underwent operations and had a decreased VAS (1.6±0.5) and an increased AOFAS score (88.3±1.8) at the last follow-up. Four patients in the high uptake group demonstrated erratic symptoms. Conclusion: SPECT/CT can be a useful diagnostic tool and helpful in designing treatment plans for symptomatic accessory navicular and os trigonum. Key Words: Accessory navicular, Tarsal, Os trigonum, SPECT/CT Received: October 5, 2011 Revised: November 7, 2011 Accepted: November 15, 2011 Bom Soo Kim, M.D. Department of Orthopaedic Surgery, Inha University Hospital, 7-206 Sinheung-dong 3-ga, Jung-gu, Incheon 400-711, Korea Tel: +82-32-890-3043 Fax: +82-32-890-3047 E-mail: bskim.os@inha.ac.kr * 이논문은 2011 년도인하대학교의지원에의하여연구되었음 (INHA-42832). 서론부주상골 (accessory navicular) 이나삼각골 (os trigonum) 은족부에서흔히발견되는부골이다. 대부분증상이없지만, 외상이나퇴행성변화로인해통증을유발할경우보존적또는수술적치료를요한다. 부골의존재여부는단순방사선촬영으로쉽게진단할수있지만, 부골의통증유발여부및수술결정은경우에따라어려울수있다. 부주 - 212 -
상골의경우, 압통이있고, 자기공명영상 (magnetic resonance imaging; MRI) 검사에서골수부종이나주변연부조직의염증소견등이관찰되면우선보존적치료를시행하고, 증상이지속되면서골주사검사 (bone scan) 에서열소 (hot spot) 로나타나면수술적치료를고려할수있다. 1) 삼각골의경우는촉진이어렵기때문에간접적으로족저굴곡시통증발생여부를확인하지만, 후종골점액낭염 (retrocalcaneal bursitis) 나주변연부조직의염증소견과감별이어려울수있다. Lidocaine 국소마취제의시험적주입은침습적이며정확도가떨어진다. 2) 마찬가지로 MRI 촬영및골주사검사를모두시행하면정확도를높일수있으나경제적이지않다. Single photon emission computed tomography (SPECT, 단일광자방출단층촬영술 )/computed tomography (CT, 컴퓨터단층촬영술 ) 는골에친화력이강한방사성동위원소 (technetium) 의 3차원적분포영상을 CT 단층영상과혼합한것이다. 3) SPECT/CT는하나의검사로병변의정확한구조와생물학적활동성을동시에검사할수있기때문에정확한통증유발부위를판단하기에용이하다. 3-6) 이러한 SPECT/CT는최근정형외과영역에도입되기시작하였으며, 족부의골연골병변이나퇴행성관절염의진단및치료방침결정에도움이된다고보고되었다. 4,6-10) 그러나족부부골의진단및치료방침의결정에있어 SPECT/CT의유용성에관한임상연구는아직발표된바없다. 따라서본연구에서는 SPECT/CT 결과에따라수술적또는보존적치료를시행한후결과를비교하여족부부골의진단및치료방침결정에있어 SPECT/CT의유용성을분석하였다. Figure 1. The treatment algorithm for symptomatic accessory tarsal bones. Depending on the uptake intensity of the lesion in the SPECT/CT, the low uptake group was treated non-operatively, while the high uptake group received operations when initial conservative managements failed. (normal 정상 ), 1 (mild), 2 (moderate), 3 (marked) 으로평가하였다. 본연구에서는 grade 0,1을저흡착군 (low uptake group, n=13) 으로, grade 2,3을고흡착군 (high uptake group, n=11) 으로분류하였다. 저흡착군에대해서는과잉활동을삼가고필요에따라비스테로이드성소염제를복용하도록하는보존적치료를 3개월이상시행하였다. 고흡착군에서는과잉활동을삼가고필요에따라초기 2주간부목고정또는비스테로이드성소염제를복용하도록하는보존적치료를 3개월간시행한후, 증상이다소호전된경우에는경과관찰하였고, 호전되지않아환자가수술적치료를원할경우에는수술을시행하였다. 대상및방법 2. 수술방법 1. 연구대상 2010년 3월부터 2011년 5월까지족부통증으로내원한환자중 x-ray에서통증부위에부골이있으면서 SPECT/ CT 촬영에동의한환자 16명 (24족) 을대상으로하였다. 남자 9명 (12족), 여자 7명 (12족) 이었다. 평균나이는 36.2세 (15~54세) 였고평균 6.8개월 (3~13개월) 추시관찰하였다. 총 24족중부주상골만있는경우가 15예, 삼각골만있는경우가 5예, 둘다있는경우가 4예있었다. 부주상골과삼각골이모두있었던 4예의경우, 두군데모두증상이있었다. 다음과같은치료지침에따라치료하였다 (Fig. 1). 증후성족부부골이의심되는 24족에대해 SPECT/CT를촬영하였고, 병소의흡착 (uptake) 정도에따라 Hart 11) grade 0 부주상골에대해서는변형된 Kidner 술식 1) 을시행하였다. 앙와위자세에서부주상골위로내측에피부절개를가하고, 부주상골과후경골건을노출시킨후연골결합을확인하였다. 부주상골을제거한후, 주상골의연골결합부위에대해소파술을시행하였다. 후경골건을 suture anchor 를이용하여주상골에고정한후, 골막, 피하조직, 피부순으로봉합하였다. 수술후 6주간단하지석고부목을착용시켰다. 삼각골에대해서는관절경적절제술을시행하였다. 복와위자세에서아킬레스건의양옆으로후외측삽입구와후내측삽입구를만들고, 장무지굴곡건및내측의신경및혈관을주의하면서삼각골을제거하였다. 수술후 1일째단하지석고부목을제거하고관절운동및체중부하를허용하 - 213 -
였다. 3. 평가방법임상적평가는수술전과최종추시시의 American Orthopaedic Foot and Ankle Society (AOFAS) midfoot scale 12) 과통증정도 (visual analogue scale, VAS) 를측정하였다. 최종추시시환자의주관적인만족도는만족 (satisfied), 약간만족 (somewhat satisfied), 불만족 (not satisfied) 으로구분하였다. 통계적검정은 SPSS (version 19, Chicago, IL, USA) 를이용하였고, 두군간의비교는 Mann-Whitney 검정을, 각군의치료전후비교는 Wilcoxon 검정을시행하였다. 결과고흡착군은저흡착군에비해초기 VAS가높았고 AOFAS 점수가낮았다 (p<0.05). 저흡착군은보존적치료만으로통계적으로유의한 VAS ( 치료전 2.2±0.9, 치료후 1.2±0.8, p<0.05) 및 AOFAS 점수 ( 치료전 83.9±4.2, 치료후 89.9±4.9, p<0.05) 의호전을보였으며, 추시기간동안증상의악화를보인환자는없었다. 고흡착군 (n=11) 에서수술한경우 (n=7), 술전에비해 VAS ( 술전 7.0±0.8, 술후 1.6±0.6, p<0.05) 및 AOFAS 점수 ( 술전 45.9±9.2, 술후 88.3±1.8, p<0.05) 가호전되었다. 최종추시시, 보존적치료를받은저흡착군과수술적치료를받은고흡착군간의 VAS (p=0.234) 및 AOFAS 점수 (p=0.434) 의유의한차이는없었다 (Table 1). 환자의주관적만족도는저흡착군의경우 13예모두만족또는약간만족이었고, 고흡착군중수술을시행받은 7 예의경우에도모두만족또는약간만족이었으며, 불만족 은없었다. 고흡착군중초기보존적치료에증상이다소호전되어경과관찰하였던 4예중, 2예는만족하였으나나머지 2예는추시기간중증상의재발및악화로불만족하여수술적치료로전환하였다. 검사및수술과관련된합병증은없었다. 고찰본연구는증후성족부부골을진단하고치료방침을계획하는데있어 SPECT/CT의유용성을보고하였다. SPECT /CT에서부골과모골 (mother bone), 즉부주상골과주상골사이또는삼각골과거골사이에흡착이증가되지않은경우에는부골이통증의원인이아니므로다른원인을찾아보거나, 심하지않은통증을유발하므로보존적치료의좋은반응을기대할수있다. 반대로, 정확히부골과모골사이에흡착이증가되어있는경우에는부골이통증을유발하므로치료의대상이된다. 단, 고흡착을보이는경우라도일차적으로는보존적치료를시행하고, 이에반응하지않는경우에는수술적치료로좋은결과를기대할수있다. 족부부골의증후성여부를판단하기위한기존의방법으로는신체검진, 국소마취제의시험적주입, MRI, 또는골주사검사등이시행되었다. 부주상골의경우에는표면에있어비교적쉽게압통을확인할수있지만, 삼각골은심부에위치해있으므로족저굴곡시통증이유발되는지여부를통해간접적으로증후성여부를추정하였다. 국소마취제의시험적주입은비교적침습적일뿐만아니라, 초음파또는투시조영영상 (fluoroscopy) 유도하에시행하는경우에도부골과모골사이에정확히약물을주입하기가쉽지않기때문에임상적으로유용하지않다. MRI 검사로는부골과모골의정확한구조적인관계를알수있고, 골수부종이있거나주위연부조직의염증소견등을통해증후성여부 Table 1. Clinical Assessment between the High and Low Uptake Groups High uptake group Low uptake group p * Visual analogue scale Initial 7.0±0.8 2.2±0.9 <0.05 Last follow-up 1.6±0.5 1.2±0.8 0.234 p <0.05 <0.05 AOFAS score Initial 45.9±9.2 83.9±4.2 <0.05 Last follow-up 88.3±1.8 89.9±4.9 0.434 p <0.05 <0.05 The values are given as the mean±standard deviation. AOFAS score, American Orthopaedic Foot and Ankle Society midfoot score. * Mann-Whitney test; Wilcoxon test, comparing the initial and last follow-up value. - 214 -
를간접적으로알수있다. 골주사검사는골아세포의대사활동을반영하므로병변의생활동성을알수있는장점이있지만, 특히족부처럼구조가복잡한경우에는병소의정확한위치를감별하기어려울수있다. 현재로서는정확한구조적인관계와생활동성을알기위해 MRI와골주사검사를각각시행하여비교하는방법으로진단을하는데, 입체적인골주사검사에서의흡착부위를 MRI 단면영상과비교하는어려움이있을수있고경제적이지못하다. SPECT/CT는골에친화력이강한방사성동위원소 (technetium) 의 3차원적분포영상을 CT 단층영상과혼합한것으로, 하나의검사로병변의정확한해부학적구조와세포의비정상적대사활동을동시에알수있기때문에정확한통증유발부위를판단하기에용이하다. 3) 이러한 SPECT/CT는수년전부터정형외과영역에도입되기시작하였으며, 최근족부영역에서유용성에관한임상보고들이발표되었다. Pagenstert 등 6) 은중족부및후족부에퇴행성관절염이있는경우, SPECT/CT가정확한병소를찾는데도움이된다고하였다. Meftah 등 9) 은거골의골연골병변의치료방침결정에있어 SPECT/CT가병소의깊이와활동성에대한추가적인정보를주어유용하다고하였다. Leumann 등 8) 도마찬가지로거골의골연골병변의치료방법의결정에있어의사에게 MRI만보여준경우와비교하여 MRI와 SPECT/CT를모두보여주었을때, 52% 에서치료계획을변경하여, SPECT/CT 가정확한진단및치료방침수립에유용하다고하였다. Knupp 등 4) 은족근관절의관절염에서 Takakura 병기와 SPECT/CT의활성도간의유의한상관관계가있다고하였다. 이외에도족부영역에서관절유합술후유합여부의평가라든지, 골수염, 스트레스골절, 족근골유합 (tarsal coalition) 및부골등에 SPECT/CT 를적용할수있지만, 10) 이와관련된임상연구는아직많지않다. SPECT/CT의단점으로는검사를위해환자에게 2~5 msv의방사선이조사된다는점이다. 이는장하지방사선일반촬영 (long leg radiographs) 2~3장을촬영할경우의조사량에해당되는데, 불필요한추가적인 X-ray나 CT를피함으로써총방사선조사량을줄일수있다. 3) SPECT/CT의비용- 효과적인측면에대한연구는아직까지이루어지지않았는데, 부골의진단에있어 SPECT/CT가 MRI와골주사검사를대체할경우총진료비용을감소시키는효과가있을것으로기대된다. 본연구결과, SPECT/CT는부골의정확한해부학적구조및비정상적골대사활동을동시에보여줌으로써진단에도움을주었고, 그결과를기준으로정한치료방침을 따랐을때좋은결과를얻을수있었다. 본연구의제한점은증례수가많지않은점과추시기간이짧은점으로, 이를보완한후속연구가필요하다. 결 론 족부부주상골또는삼각골의증후성여부를판단하는데 SPECT/CT가유용하였다. 또한, SPECT/CT에서병소의흡착정도는증상의정도와연관이있었으며, 고흡착군에서는보존적치료로충분한증상의호전이없어서수술적치료를요했던경우가많았다. 따라서, 족부부골의치료방침결정에있어 SPECT/CT는유용하게활용될수있을것으로생각한다. REFERENCES 1. Lee JS, Youn H, Choi WJ, Lee JW. Comparison of clinical outcome of excision versus osteosynthesis in type ii accessory navicular. J Korean Foot Ankle Soc. 2011;15:72-8. 2. Karasick D, Schweitzer ME. The os trigonum syndrome: Imaging features. AJR Am J Roentgenol. 1996;166:125-9. 3. Hirschmann MT, Davda K, Rasch H, Arnold MP, Friederich NF. Clinical value of combined single photon emission computerized tomography and conventional computer tomography (SPECT/CT) in sports medicine. Sports Med Arthrosc. 2011;19:174-81. 4. Knupp M, Pagenstert GI, Barg A, Bolliger L, Easley ME, Hintermann B. SPECT/CT compared with conventional imaging modalities for the assessment of the varus and valgus malaligned hindfoot. J Orthop Res. 2009;27:1461-6. 5. Linke R, Kuwert T, Uder M, Forst R, Wuest W. Skeletal SPECT/CT of the peripheral extremities. AJR Am J Roentgenol. 2010;194:W329-35. 6. Pagenstert GI, Barg A, Leumann AG, et al. SPECT/CT imaging in degenerative joint disease of the foot and ankle. J Bone Joint Surg Br. 2009;91:1191-6. 7. Kamaleshwaran KK, Bhattacharya A, Aggarwal S, Harisankar CN, Mittal BR. Bilateral tarsal coalitions detected on Tc-99m methylene diphosphonate bone scan with SPECT/CT. Clin Nucl Med. 2010;35:537-9. 8. Leumann A, Valderrabano V, Plaass C, et al. A novel imaging method for osteochondral lesions of the talus--comparison of SPECT/CT with mri. Am J Sports Med. 2011;39:1095-101. 9. Meftah M, Katchis SD, Scharf SC, Mintz DN, Klein DA, Weiner LS. SPECT/CT in the management of osteochondral lesions of the talus. Foot Ankle Int. 2011;32:233-8. 10. Mohan HK, Gnanasegaran G, Vijayanathan S, Fogelman I. SPECT/CT in imaging foot and ankle pathology-the demise of other coregistration techniques. Semin Nucl Med. 2010; - 215 -
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