SAGttTAL MECIIANICAL AXIS OF TIIE LOWER EX□ 田郵凋『Y IN ELDERLY FEMALES

ギ,雑sllgaIIla RガKobay甑 A,親 も施阻め Y,中Iwaki H,ネInOtt F,ⅢTada M,41w水 血 K,球Ohta Y,雑NakaBawa S,練 Kadoya Y,をTakaOka K寄Osaka C■y Univcrsity Medlcal School,Osaka,Japan,

suHamttmsic,med.osaka―cLI.ac,lD

INェRODUCT10N:■has been repolted dlat attlment ofprosdlesis is one ofthe lnost

impottmt factors tt dtt longcvity of total knee anoplasty(TKA5,Tcachieve all accurate and uroduCablc al亀要班nttt h TKA, navlgattonsystem地益recently been dtteloped.To develop such navigatlon wstem,adequate hfoIIIlatiOn ofttignment troun the femoral head to ttЮ側岨els essential.

Altlouか coronal ttg―ent of the lower extremity h noIIna鋭瑚eCtS has been shown h maayコ 斡Orts,上de立 由回阻よmお avallable

on sagttal alittment of tte lower extremty h wettht―bearhg becauseof the dittcutt to takc the radおgraph of鈍徒 lower extrcmity hwcight―bearlng

We previously玉 コorted血 筑 the simple method to take tteradiOgFaph Oflower eremty in welght_beamg mll extenslon(1),and

腕 tthe lnettanical axis o臥)Of10Wer tttrenlty h healthy young mttedtt not pass arouぶdle center ofl血3knee h磁 夢ねl plane(2).HoweVe毛dderly females who are de leadtt can価 的に Of TKA may havedirerent anatomical morphology from young male.

m c p u l p O S e o f t t i s 」岨 y l s t o e x a l m e d l e M A o f l o w e r e x t r e m 町血 weight_bearmg tt exten並温h elderly fcmales宙血 ut osteoa耐航ts.

剛 THODS:

Coronal and sagitt radiographs werc made of 血 80 1owere x t r e t t t e s o f 4 0 h e a l h y f e m a r e J a p a n e s e v o l u n t e e r s ( I I l e a n a g e o f 7 1 , 9

years,range is 66-84 yearsy ttth stand血3 Au volunteers have noc o m p l a m t a n d n o d e f o m i t y i n a p p e a r a n c e t t t h e t t b i l a t e r a l k n e e s , h " s

a n d れ出e s . F o r 研よ明d o n o f t h e o t t e o 斌脱 t s o f d l e k n e e , K d l B r e n ―Lawcnce classiflcation(3)was uSed.h dlis sttes,su町 ∝tS Of Oade 0were txぅluded. In d賞3 80 1owg extremtes, therefore, S2 1owcrex位●m品 es were hcluded in the cu向に独t study.Coronalっ比配

Standardized antcropostenor radiograph ofdle bwer extremiけwih山e sdttect standing was made by tte posltlo― g accordmg to tlememod ofMoreland(4).

The femorotibial angle cTA)(5)and wdBht‐ bear逸 岡tO(WBR)

(6)were mCaswedSttidtt Dlane

L a t e r a l r a dおg r a p h o f t t e l o w c r e x t r e mⅢ血 o l l e―L g g e d s t a n d i n g

po豆血n was made in the mehod ofour preuous reports(1):1.ご ミ Swas rotated so hat fcmoral head could be visualittd by lower energy

setting ofx―ray beam.2.□ 拒 hee was ttily exterlded.3.■拒 posttredge of medial and iateral felnoFal COndyle wereぷi課胡 so tlat rotationof dle lower emty was cOntrolled and standattized,4,A graduated

lead―lo組胡 awlic ilteF WaS plac胡 血 血 nt of the c制 臨賦劇 x_raybealn tt latral radiomph SO ttat hc femoral hcad was apphed hD

energy x―ray9 and the knee and dle anklc were applicd relat持dy lowerenergy x―ray.

Sagit絶狂 mechanよ光述 旗 s was dermed as tte lhe dram ■ om ttecenter oftt femoral head to dtt centcr oftte talocRraljO血t(Figure l)ャStti祖劇 femOral WBR and弱 胡 tibiぶWBR were defmed as flgllre 2

(2).A1l the pamlneters on radiographs were measured usmg ttage

anttyzer(Q■iCk Grain;Vtton 3.2,Inoteckl and Calcultted to onedeciIIlal placc.

RESULTS:

C O F O I l a l D l a n e

距 A wa s 1 7 6 . 8 + / _ 3 . l K I n e a n t /―stan d淳配 devi a t l o n r m n g e , 1 7 0 . 6t o 1 8 3 . 8 ] ) d e g r e c s . W B R w a s 3 2 . 2 +た12,7 K r a n g e , 7 . 4 t o 5 8 . 0 ) ,S狙 胡 Dlan C

sagiml fmOral WBR was 52.4■ /‐29.5.Sagital tbial WBR waswas 45。8+/-43.3.Sagit協 l femoral WBR and sagital tbial WBR had

隅 裸 瑞 浦 無 堵 b押 軸 洲 描 錨 憾 紺 鮮 品徒 kneej o m t w a s O d e g r e e e x t e n s i o L s a g i t t a l f e m o r a l W B R a n d s a g i t t a l

tibial WBR were calculated■om the regresdon ttmcs in FIpre 3 to bewas 47.6 and 38.9,respectively.

DISCUN10N:

血 曲ユs elderly female ttctt MA oflower eremty dtt notpassthe

ceはkl ofthe knee(32.20/c Hxtthally and 38 90/s posterloFly On the tbial

p l a t e a l l l a S i n y o u n g m a l e s t t e s o 3 9 % m e d i a l l y a n d 3 3 . 0 % P o s t e r i o r l yon dle tibial plateau)(2)ci81re 4)、The MA of elderly female was,howevett passed a tttde more post9dorly than dat of young male,It is

unclear whether thc cause oft姑s differencc is age or sex.Fumer sttdyh a s t o b e d o n e t o e l u c i d a t c t t s p o m t

T h e c ―n t s m d y d O w e d i 叩碗 a n t 的脇 おI I S f O r t t i g n m e n t i nTKA,espedally witl配】vigation systelns,and osteotomyt

Figure l:Lateral dttram Oftle lower extrelmty tt oneriegged hndhg

posmon and saginl mechttal axis were shou.

軸 gure 2:Dttraln sho―g the Saginl femOraI WBR and SagitaltibialWBR Sagitt Semoral WBR=A/KAtB)x100.Sagital tihal WBR=

C/KCttD)x100S箸 的劇 Fにせh舶工cal aus=s、 こ代.

R2=o948,pく o o001R2=a936,pく o o001

Fをure 3:Scater diagrams of the angle of the kncc joht and sagiml

parametcrs.SagimlfemOFtt WBR o代)and ttgital tbial WBR c)had血e stattdcally signiflcaIIt correlttion wttl dle angtt of佐血ee.

Figure 4助 agmm sho― g tlelocattn ofthe MA on ight thA

plateau,?ゅelderly female and c)young malc(2)。

REFERENCES:

( 1 ) M h t t a Y e t a l . T r a n s O R S。2 0 0 5 , 3 1 0。

( 2 )ぶ血恵ia C t a l T r a n s」O A . 2 0 0 4

(3)Kel131m JH,Lawence JC.Ann Rheum Dis.1958;17:388-397.

律)MOrelalld JR et al.J Bonc Jomt Surg Am.1987o9:745-9.

(5)K対誼10 T et al.htOmop。1979;3:37-45.

c)Andr― Metal.JOmop酪 1996;14i289-95.AFF工 五MEIコD INS□『丁肛ONSFOR CO‐ AtFIIORSi革 Osaka Ro航Hotttal,OSaktt Japan‐ Kanstt Rostt Hospital,Hyougo,」apan

3 A

53rd Annual Meeting of the Orthopaedic Research Society

Poster No: 0758