대한견 주관절학회지제14권제1호 Clinics in Shoulder and Elbow Review Article Volume 14, Number 1, June, 2011 doi:10.5397/cise.2011.14.1.140 요골두치환술의임상적적용 고려대학교의과대학정형외과학교실 문준규 Clinical Application of Radial Head Prosthesis Jun-Gyu Moon, M.D. Department of Orthopedic Surgery, Korea University Medical College Purpose: Installing a radial head prosthesis has developed into a reliable procedure to replace the native radial head for treating unreconstructible radial head fracture when this is associated with an unstable elbow or forearm. A variety of implants have been developed and these are now commercially available. This article reviews the literature related to the indications, the available implants and the surgical techniques of radial head replacement arthroplasty. Materials and Methods: The main indication for a metallic radial head prosthesis is a comminuted fracture that is not amenable to reconstruction, and particularly if it is associated with complex elbow injuries. Excision of the radial head should be avoided in the presence of combined injured ligaments or interosseous membrane injury. Three different implants are available in Korea, including the bipolar, press fit monopolar and loose fit monopolar radial head prostheses. A primary technical goal of radial head arthroplasty is the insertion of an implant that closely replicates the native radial head. The major pitfall when using a metallic radial head prosthesis is the insertion of a longer implant, which results in overstuffing of the radiocapitellar joint. Results and Conclusion: Satisfactory clinical results can be anticipated when a radial head prosthesis is used for the correct indications and when a systemic approach is undertaken to ensure proper sizing. For the future studies, we need data regarding the long term outcomes and comparison of the various types of prostheses. Key Words: Radial head, Fracture, Replacement 통신저자 : 문준규서울특별시구로구구로동길 97 고려대학교구로병원정형외과 Tel: 02) 2626-3089, Fax: 02) 2626-1164, E-mail: moonjg@korea.ac.kr 접수일 : 2011 년 6 월 2 일, 게재확정일 : 2011 년 6 월 27 일 140
문준규 : 요골두치환술의임상적적용 서론요골두치환술 (radial head arthroplasty) 은주관절또는전완부의복합골절-탈구 (complex fracturedislocation) 손상에서고정할수없는요골두분쇄골절에적응된다. 과거시행되었던요골두절제술은사체실험을통한요골두의생역학적역할이알려지고임상적인합병증이보고되면서그적응증이제한된실정이다. 1,2) 초기에사용된실리콘재질의치환물은약한생역학적인성질과활액막염발생등의생물학적단점으로최근에는거의사용되고있지않다. 3,4) 금속을이용한요골두치환물은문헌에의하면 1941년 Speed 5) 가처음금속을이용한치환술을발표한이후영국의 Harrington 등 6) 이 1961년부터티타늄 (titanium) 재질의치환물을사용하였고 Knight 등은비탈리움 (vitallium) 요골두치환물을이용한임상결과를발표하였다. 7) 이후다양한디자인의금속성요골두치환물 (metallic radial head prostheses) 이개발되어현재까지사용되고있다. 국내에서도 2005년부터양극성 (bipolar) 요골두치환물이사용되기시작하였고최근단극성 (unipolar) 치환물도수입되어사용되고있다. 임상적인결과는단기추시결과가대부분이지만대체적으로만족할만한결과들이보고되고있다. 6,8-10) 하지만최근중-장기추시결과가발표되면서합병증에대한임상결과도발표되고있다. 11) 특히요골두의높이가과도하게치환되는경우 (overstuffing) 가불량한 예후를가져오는요인중하나로알려졌다. 12) 이를방지하는여러방법들이소개되었고요골두치환술의적합한적응증, 적절한치환물의선택및정확한수술술기에대한중요성이강조되고있다. 적응증요골두치환술의주적응증은내고정을하기어려운요골두의분쇄골절이다. 요골두골절의 Mason 분류 3 또는 4에해당되는골절로요골두의분쇄골편을안정적으로해부학적내고정을못하거나요경부골절이동반된경우이다. 이런경우가능한한먼저내고정을시도해보는것이우선이고일부저자들은관혈적정복및내고정을시도하여좋은결과를보고한바있지만, 13) 불유합, 부정유합및조기실패율이높아치환술이선호되는경우가많다. 14) 또한주관절측부인대파열, 전완부골간막등의연부조직손상이나구상돌기골절등의동반골절이있는경우에는주관절의불안정성이심하여요골두치환술은필수적이다. 15) 요골두절제술의경우동반손상이없는요골두골절에는장기합병증이없다는보고도있으나복합골절에시행되었을경우주관절통증, 요골의상방전이, 파지력감소, 외반불안정성, 관절염등의합병증이올수있다. 1,16,17) 그외의적응증으로요골두의부정유합이나불유합이있으면서만성적인주관절불안정성이있는경우이다 (Fig. 1). Fig. 1. AP radiograph showing a comminuted radial head fracture. Resected fragments of a radial head fracture. 141
대한견 주관절학회지제 14 권제 1 호 국내사용요골두치환물 (Radial head prostheses) 현재일반적으로사용되는요골두치환물은금속재질이며치환물성격에따라양극성 / 단극성 (bipolar/ unipolar), 시멘트 / 무시멘트 (cemented/cementless) 스템, 일체형 / 조합형 (monoblock/modular) 등으로분류될수있다. 2011년 3월현재국내시장에서사용되는금속요골두치환물은세종류인데각각특징을가지고있다 (Table 1), (Fig. 2). 양극성요골두치환물은 Judet 등에의해개발되어널리사용되고있는데요골두가스템과 35 도까지경사각이가능하게설계되었다. 18) 이러한요골두의움직임은요골두-소두관절의접촉을증가시키는역할을한다. 하지만양극성구조는생역학적인측면에서단극성보다관절의안정성이떨어지고임상적으로는요골두가해리 (dissociation) 되는합병증이보고되기도하였다. 19-21) 또한폴리에틸렌마모로스템의이완이발생할수있으며재치환술이어렵다는단점이있다. 10,22) 무시멘트단극성요골두치환물은스템의고정방법에따라압박 고정 (press fit) 스템과이완고정 (loose fit) 스템치환물로나눌수있다. 압박고정스템은요골경부의골수강에가능한최대직경의스템을삽입하여스템의미세운동 (micromotion) 을줄이고스템주위의골성장 (bony ingrowth) 을유도하는치환물이다. 요골두가요골내에서움직임이없으므로생역학적안정성면에서는양극성보다우월하다. 20,23) 하지만사람마다요골두모양이다르고원요골두 (native radial head) 와동일한요골두치환물을만들기불가능하기때문에움직임이없는견고한치환물의삽입은이러한차이를극복할여유가없어서요골두-소두관절의접촉이일정하지않을수있다. 24,25) 또한과도한직경의스템을삽입할수있고이로인한골절이발생할수있다. 이완고정스템은이러한단점을보완할수있도록요경부골수강의직경보다작은스템을삽입한다. spacer 역할이며의도적인이완성삽입으로치환물의움직임이해부학적으로불일치한요골두를보상해주는개념이다. 8,26) 하지만추시과정에서스템의이완이현저하게나타나는경우가있으며이로인해주관절부에동통을유발하기도한다. 6,9) Table 1. Three different types of radial head implants used in Korea RHS Ascension Evolve Tornier, France Ascension, USA Wright medical, USA Bipolar Unipolar Unipolar Cemented Press fit cementless Loose fit cementless Long, slotted stem Tapered stem Smooth straight stem 2 heads, 2 stems 6 heads, 4 stems 18 heads, 18 stems A B C Fig. 2. (A) Bipolar RHS, (B) Ascension modular radial head, (C) Evolve modular radial head. 142
문준규 : 요골두치환술의임상적적용 다양한치환물이개발되고시장에나와있지만대부분의경우는조합형 (modular type) 으로요골두와스템이조립 (in situ assembly) 되어삽입된다. 최근출시된치환물은다양한증례에맞게 1~2 mm 크기차이의임플란트들로구성되어원래의요골두로재건할수있는선택폭이넓다. 수술술기수술전계획에서요골두치환술의적응증을확인한다. 이때요골두골편이 3개이상의분쇄골절인경우먼저내고정을시도하더라도안정된고정이힘들수있다는경우를예상하고치환술도같이대비하여야한다. 수상측과건측방사선사진을촬영하여요골두의직경 (diameter), 높이 (height), 경부 (neck) 의직경, 골절선의모양과높이, 척- 상완관절간격 (ulno humeral joint space), 완관절의척골변이 (ulna variance) 등을측정한다. 수술전 CT 사진도해부학적지표를측정하는데도움이된다. 치환물의선택은골절이요골두에만있는경우에는대부분의제품이무난하게적용될수있지만, 경부하단까지연장된골절이나재치환술 (revision) 의경우에는다양한크기의임플란트를조립할수있는치환물이필요할수있다. 본문의내용은무시멘트단극성요골두치환물을기준으로설명을하고자한다. 수술접근법은앙와위에서외측또는후방절개를시행하여요골두를노출시킨다. 구상돌기골절이나내측측부인대봉합이필요할경우에는후방단일절개가유용하다. 전통적인 Kocher 접근법은주근 (anconeous) 과척수근신근 (extensor carpi ulnaris) 의간격을통한접근법이고 Kaplan 접근법은외측으로직접접근하여장요수근신근 (extensor carpi radialis longus) 과총수지신전근 (extensor digitorum communis) 간격을통해요골두에접근한다. 이때외측척골측부인대 (lateral ulnar collateral ligament) 와후방골간신경 (posterior interosseous nerve) 의손상을주의하여야한다. 요골두의전후방정중선 (midaxial line of the radial head) 상방으로관절낭을절개함으로써외측척골측부인대의손상을방지할수있다. 복합골절의경우에는외측척골측부인대가신전근들과함께파열되어있는경우가흔하여파열된틈을이용하여요골두를노출시키는것이용이하다. 관절낭은요측측부인대 (radial collateral ligament) 와윤상인대 (annular ligament) 와함께횡절개하고요골경부의회외근 (supinator) 까지노출시키면시야가확보된다. 요골두골편의형태와분쇄정도를기준으로내고정술, 절제술및치환술여부를결정한다. 절제술을시행하였을때는 외반불안정성및후외방회전불안정성이잔존하는지반드시확인하고골간막손상으로요골의축성불안정성 (axial instability) 이있는지도확인해야한다. 요골두치환술이결정되면남아있는요골두부분을요골두-경부경계에서작은전기톱 (microsagittal saw) 으로절제한다. 이때전완부를 60 도이상회외상태에서요골경부의직각으로절제하면전완부의회전축 (rotational axis) 에가깝게절제술을할수있다. 27,28) 절제한골편은작은골편들과수집하여요골두의직경및두께를측정하는데이용된다. 요골골두의절제면 (cutting surface) 이편평하지않는경우가흔한데이경우가장적게절제된부분의두께를측정하여치환물의높이를결정하여야과신장 (overstuffing) 을방지할수있다 29). 요골두의직경은경계선상에서는작은직경을선택하는것이추천된다. 요골경부의골수강은피질골의손상을최소화하여작은직경부터점차적으로확공한다. 최종스템의직경은치환물의종류에따라최대직경또는한사이즈작은직경의스템을선택한다. 치환물의크기가결정되면 trial 임플란트를삽입하여치환물의적절성을평가한다. 요골두치환물의적절한높이의복원은임상적으로중요한데원래의길이보다늘어나는 overstuffing과줄어드는 understuffing 모두바람직하지않다. 30) 특히 overstuffing은술후운동제한과통증을유발하는심각한원인으로수술시반드시피해야한다. 12,31) Overstuffing 방지하기위해여러방법들이소개되었다. Doornberg 등은요골두가구상돌기의외측면경계선보다 1 mm이내로위치한다는것을지표로이용한다고발표하였다. 32) Athwal 등은척-상완관절면의불일치상태가 overstuffing을암시한다고하였다. 33) Moon 등은요골조면 (radial tuberosity) 를이용하여요골두높이를측정하는방법을소개하였다. 34) 그외에도요골절흔 (radial notch) 을이용하거나완관절의척골변이를관찰하여 overstuffing을평가할수있다. 35) 하지만요골두높이가수 mm 정도의작은변화이므로방사선사진을이용하는것은한계가있을수있다. 36) 따라서수술중에가능한모든방법을이용하는것이 overstuffing을줄이는데도움을줄수있을것이다. 적절한치환물의삽입후관절운동및안정성을확인하고외측척골측부인대및신전근을봉합한다. 동반골절이있을때는내고정을시행하고최종적으로주관절의안정성을평가하여불안정성이남아있을때는내측측부인대 (medial collateral ligament) 봉합또는외고정장치를고려한다. 술후재활은동반손상및주관절의안정성에따라전완부의고정위치, 관절운동시기가달라진다. 이소성골형성 (heterotopic 143
대한견 주관절학회지제 14 권제 1 호 ossification) 예방을위해과도한수동적운동은피하고 Indomethacin 또는 NSAID 처방이필요하다. 결 금속성요골두치환술은주관절의복합골절에서고정할수없는요골두를대치하여주관절의안정성을회복시키는합리적인수술법이다. 정확한수술술기와 overstuffing에대한주의가필요하며동반손상에대한적절한치료가필수적이다. 론 REFERENCES 1. Ikeda M, Oka Y. Function after early radial head resection for fracture: a retrospective evaluation of 15 patients followed for 3-18 years. Acta Orthop Scand. 2000;71:191-4. 2. Morrey BF, Tanaka S, An KN. Valgus stability of the elbow. A definition of primary and secondary constraints. Clin Orthop Relat Res. 1991;187-95. 3. Moon JG, Southgate RD, Fitzsimmons JS, O Driscoll SW. Arthroscopic removal of the failed silicone radial head prosthesis. Knee Surg Sports Traumatol Arthrosc. 2009;17:1243-8. 4. Vanderwilde RS, Morrey BF, Melberg MWVinh TN. Inflammatory arthritis after failure of silicone rubber replacement of the radial head. J Bone Joint Surg Br. 1994;76:78-81. 5. Speed K. Ferrule caps for the head of the radius. Surg Gynecol Obset. 1941;73:845-50. 6. Harrington IJ, Sekyi-Otu A, Barrington TW, Evans DC, Tuli V. The functional outcome with metallic radial head implants in the treatment of unstable elbow fractures: a long-term review. J Trauma. 2001;50:46-52. 7. Knight DJ, Rymaszewski LA, Amis AA, Miller JH. Primary replacement of the fractured radial head with a metal prosthesis. J Bone Joint Surg Br. 1993;75:572-6. 8. Grewal R, MacDermid JC, Faber KJ, Drosdowech DS, King GJ. Comminuted radial head fractures treated with a modular metallic radial head arthroplasty. Study of outcomes. J Bone Joint Surg Am. 2006;88: 2192-200. 9. Moro JK, Werier J, MacDermid JC, Patterson SD, King GJ. Arthroplasty with a metal radial head for unreconstructible fractures of the radial head. J Bone Joint Surg Am. 2001;83:1201-11. 10. Popovic N, Lemaire R, Georis P, Gillet P. Midterm results with a bipolar radial head prosthesis: radiographic evidence of loosening at the bone-cement interface. J Bone Joint Surg Am. 2007;89:2469-76. 11. Van Riet RP, Sanchez-Sotelo J, Morrey BF. Failure of metal radial head replacement. J Bone Joint Surg Br. 2010;92:661-7. 12. Van Riet RP, Van Glabbeek F, Verborgt O, Gielen J. Capitellar erosion caused by a metal radial head prosthesis. A case report. J Bone Joint Surg Am. 2004;86:1061-4. 13. Ikeda M, Sugiyama K, Kang C, Takagaki T, Oka Y. Comminuted fractures of the radial head. Comparison of resection and internal fixation. J Bone Joint Surg Am. 2005;87:76-84. 14. Ring D, Quintero J, Jupiter JB. Open reduction and internal fixation of fractures of the radial head. J Bone Joint Surg Am. 2002;84-A:1811-5. 15. Davidson PA, Moseley JB, Jr. Tullos HS. Radial head fracture. A potentially complex injury. Clin Orthop Relat Res. 1993;224-30. 16. Herbertsson P, Hasserius R, Josefsson PO, et al. Mason type IV fractures of the elbow: a 14- to 46-year follow-up study. J Bone Joint Surg Br. 2009;91:1499-504. 17. Johnson JA, Beingessner DM, Gordon KD, Dunning CE, Stacpoole RA, King GJ. Kinematics and stability of the fractured and implant-reconstructed radial head. J Shoulder Elbow Surg. 2005;14:195-201. 18. Judet T, Garreau de Loubresse C, Piriou P, Charnley G. A floating prosthesis for radial-head fractures. J Bone Joint Surg Br. 1996;78:244-9. 19. Herald J, O Driscoll S. Complete dissociation of a bipolar radial head prosthesis: a case report. J Shoulder Elbow Surg. 2008;17:e22-3. 20. Moon JG, Berglund LJ, Zachary D, An KN, O Driscoll SW. Radiocapitellar joint stability with bipolar versus monopolar radial head prostheses. J Shoulder Elbow Surg. 2009;18:779-84. 21. O Driscoll SW, Herald J. Symptomatic failure of snap-on bipolar radial head prosthesis. J Shoulder Elbow Surg. 2009;18:e7-11. 22. Burkhart KJ, Mattyasovszky SG, Runkel M et al. Mid-to long-term results after bipolar radial head arthroplasty. J Shoulder Elbow Surg. 2010;19:965-72. 23. Schneeberger AG, Sadowski MM, Jacob HA. Coronoid process and radial head as posterolateral rotatory stabilizers of the elbow. J Bone Joint Surg Am. 2004; 86:975-82. 24. Calfee R, Madom I, Weiss AP. Radial head arthroplasty. J Hand Surg Am. 2006;31:314-21. 25. Yian E, Steens W, Lingenfelter E, Schneeberger AG. Malpositioning of radial head prostheses: an in vitro study. J Shoulder Elbow Surg. 2008;17:663-70. 26. Van Riet RP, Van Glabbeek F, Neale PG, Bortier H, An KN, O Driscoll SW. The noncircular shape of the radial head. J Hand Surg Am. 2003;28:972-8. 27. Koslowsky TC, Beyer F, Germund I, Mader K, Jergas M, Koebke J. Morphometric parameters of the radial neck: an anatomical study. Surg Radiol Anat. 144
문준규 : 요골두치환술의임상적적용 2007;29:279-84.z 28. Roidis N, Stevanovic M, Martirosian A, Abbott DD, McPherson EJ, Itamura JM. A radiographic study of proximal radius anatomy with implications in radial head replacement. J Shoulder Elbow Surg. 2003;12: 380-4. 29. Ring D, King G. Radial head arthroplasty with a modular metal spacer to treat acute traumatic elbow instability. Surgical technique. J Bone Joint Surg Am. 2008;90 Suppl :63-73. 30. Van Glabbeek F, Van Riet RP, Baumfeld JA, et al. Detrimental effects of overstuffing or understuffing with a radial head replacement in the medial collateral-ligament deficient elbow. J Bone Joint Surg Am. 2004;86:2629-35. 31. Birkedal JP, Deal DN, Ruch DS. Loss of flexion after radial head replacement. J Shoulder Elbow Surg. 2004;13:208-13. 32. Doornberg JN, Linzel DS, Zurakowski D, Ring D. Reference points for radial head prosthesis size. J Hand Surg Am. 2006;31:53-7. 33. Athwal GS, Frank SG, Grewal R, Faber KJ, Johnson J, King GJ. Determination of correct implant size in radial head arthroplasty to avoid overlengthening: surgical technique. J Bone Joint Surg Am. 2010;92 Suppl :250-7. 34. Moon JG, Southgate RD, Fitzsimmons JS, O Driscoll SW. Simple overlay device for determining radial head and neck height. Skeletal Radiol. 2010;39:915-20. 35. Van Riet RP, van Glabbeek F, de Weerdt W, Oemar J, Bortier H. Validation of the lesser sigmoid notch of the ulna as a reference point for accurate placement of a prosthesis for the head of the radius: a cadaver study. J Bone Joint Surg Br. 2007;89:413-6. 36. Shors HC, Gannon C, Miller MC, Schmidt CC, Baratz ME. Plain radiographs are inadequate to identify overlengthening with a radial head prosthesis. J Hand Surg Am. 2008;33:335-9. 초록 목적 : 금속요골두치환술은주관절불안정성을동반한고정할수없는분쇄된요골두골절의치료로최근다양한임플란트의개발로널리사용되고있다. 저자는금속성요골두치환술의적응증과국내에사용중인임플란트의종류와수술술기를문헌고찰과함께기술하고자한다. 대상및방법 : 요골두치환술의주적응증은동반된연부조직손상으로인한주관절의불안정성이있고, 요골두의분쇄골절로안정적인내고정이불가능한골절이다. 이러한경우과거시행되었던요골두절제술은많은합병증의발생으로금기시되고있다. 현재국내에서는양극성, 압박고정단극성및이완고정단극성임플란트의 3종류가수입되어사용되고있다. 요골두치환술은궁극적으로원래의요골두의크기와길이로복원하는것이중요하다. 과도하게긴요골두의삽입은흔한합병증으로수술시주의가필요하다. 결과및결론 : 요골두치환술은적절한적응증과정확한수술술기로만족할만한임상적결과를얻을수있다. 향후장기추시연구와다양한치환물들의임상적인비교연구가필요하다. 색인단어 : 요골두, 골절, 치환 145