Tính toán mô phỏng và thiết kế ốc chân cung dùng trong cố định cột sống

NGHIEN c t f u - TRAO B | TINH T O A N M PHONG VA THIET KE OC C H A N CUNG DUNG TRONG c DINH C O T S N G COMPUTATION AND DESIGN FOR SPINE SCREW USED IN SPINE SURGERY PGS, TS Vo Van Thanh', PGS, TS TrUOng Tich Thieng ThS NguySn Thanh Nh^ •Khoa Cot s6ng A Benh vien Ch& thUong Chinh hinh, quto 5, TP Hfi Chi Minh 2Tni6ng Dai hoc Bach Khoa TR H6 Chi Minh TOM TAT Bciibdot^p trung vao viic tinh toan mo plidng itng xil cita kit cdu 6c chan cung sit dung tron phdu dieu tri chdn thUUng cong cot song Nguyen tic thiet kg la tham khdo tit mm dc chdn cu khdu ciia nUdc ngoai, hieu chinh mot so chi tiet dephu hap vdi dieu kien che tao vd vat Ueu co d canh do, viec hieu chinh budc ren vd goc ren dMc thUc hien nhdm tdng cUdng khd ndng tif hdm c han che lUc hUdng kinh ldm mu oc, nhang nguyen nhdn ldm hU hong 6c qua trinh la sd dung Cdc thiet ke 6c chdn cung de xudt da dMc tien hdnh gia cong vd thii nghiem kiem chiing khdng dinh khd ndng hoat dong tot cua 6c TU khoa: 6c chdn cung oc chdn cung ddn true, da true ABSTRACT In this paper, the authors perform the computation to simulate the behavior of spine screw used in the surgical treatment of injury, deformity ofthe spine The designs of spine screw are refer the imported ones and modified in some details to conform to the domestic ability of manufactur materials Moreover, the modifications for screw pitch and angle are performed to enhance selfability and reduce the radial reaction that makes the screw break down during the tightening an process The suggested spine screw designs are manufactured and tested to ensure the good wo capability Key words: Spine screw, multi-axial, mono-axial spine screw TAP CHI'CO KHl VIET NAM, S6 nam 2013 NGHIEN CUfU-TRAODdi - c cd ren can ddn hoat ddng tdt (silt chat hdn vao xfldng) hdn 6c cd ren deu GlOl THiEU Vile nghien cflu va san xuat dc chan eung phue vu dilu tri chan thfldng, cong cdt sdng da dfldc thflc hi$n rat ldu tfl thap nien 70 eua t h i ky trUdc bdi edc nfldc tien tien, cd nen y hpc phat triln ldu ddi nhU: Phap, Hoa Ky, Dflc, v v Tuy nhien, dp ylu td ddc quyen va chi phi nghiin cflu, san xuat dat dd, gia edc loai dc nhap khau tren thi trfldng so vdi thu nhdp ngfldi ddn nUde Id rat eao, ngUdi benh nfldc thdng thudng phai hang chuc den hang tram trilu ddng eho eae ca gay xUdng sdng hoac cong cdt sdng Hiln tai mdt sd nUdc chau A nhU: Hdn Qudc, Thai Lan, Trung Qudc cung da nghiin cflu vd san xuat thfldng mai thdnh cdng oc chan eung, nhiln chdt Ifldng cdn ban e h i va gia cung cdn kha cao so vdi thu nhap trung binh ngudi ddn Viet Nam [1], [2], [3] - Trong qud trinh lap, phan dau tren eua 6c thudng bi bung dflng lflc silt manh de CO dinh ddn Khi dd, lien kit buldng dai 6c khdng cdn tac dung, phdi bd di bd dc dd - Ben canh dd, da lap vdo xfldng sdng ngfldi benh, qud trinh sfl dung cd trfldng hpp buldng tfl thdd Idng, lam lien kit khdng edn bao dam, nguy hilm cho benh nhdn - Ngoai qud trinh sfl dimg, he thdng 6c cdn bi bdt on dinh mdi, cd trfldng hdp ldu bi gay ndi T?i Vilt Nam, vile nghien cflu, thilt ke va che tao dc chan cung lan ddu tiln da va dang dUdc thiic hiln vdi sU chfl tri cfla khoa Cdt sdng A - Benh vi?n Chdn thfldng Chinh hinh I phd Hd Chi Minh, cung phdi hdp vdi trung tdm I Nghiin cflu va Che tap Thiet bi mdi - Sd Khoa |hpc va Cdng nghl TP HCM va Khoa Khoa hpc n g dung, Trfldng Dai hpe Bdch Khoa TR HCM Qua trinh nghiin cflu gdm cac giai doan la thilt ,ke, chl tao Idem nghi?m vd flng dung lam san Hinh L Mdu dc ddn true vd da true hdng Stryker Trong pham vi bdi bao nay, cdc tdc gid trinh bdy (Hoa Ky) che tao cdc ndi dung lien quan din van d l tinh toan md phdng, thiet k l va kilm nghiim edc ehi tilu dd d l THIET KE MAU OC C H A N CUNG VOl CAC thilt ke Vile tinh todn md phdng flng xfl HIEU CHINH cd he 6c chan cung dfldc thflc hien bang phUdng phap phdn tfl hflu han vdi chfldng trinh ANSYS Mdt nhflng khd khan ldn cua de tai THAM KHAO MOT SO MAU OC CHAN t u N G D O N l / O C NGOAl SAN XUAT '' Qua tham khap mdt sd mau dc chan cung jdo nfldc ngodi (Hoa Ky, Han Qudc, Trung Qudc) idn xuat, vdi kinh nghiem sfl dung dc ldu nam :fla cac bdc si khoa Cpt sdng A, Benh vien Chan hfldng Chinh hinh cd the rut mdt sd flu nhflpc hem cua tflng loai dc nhfl sau: la vile tham khao mau dc nfldc ngoai san xudt Vdi cae mau dc nay, chi cd the tham khdo vl hinh ddng va kich thUdc, van de vat lieu va phUdng phdp gia cdng che tao 6c la bi m^t edng nghe cfla edc hang san xuat Do dd nhiem vu ddt la phai dUa cac thilt k l cho dc ehan cung cd the c h l tao dupc nUdc vdi loai vat lieu cd the cd dUdc (Titan ho§e Inox 316L) Viec thay ddi, hieu chinh cdc kich thude la dieu bat bude de phu hdp vdi loai vat lieu cd dUdc JM TAP C H i C O KHi VI$T NAM, Sd nam 2013 NGHIEN C U T U - T R A O D O I 3.1 Lfla chon toai ren cho than dc Chpn thiet k l than dc ed ren can ddn nham tang dd eflng cua than 6c so vdi thiet k l ren deu, ban ehi nguy cd gay than dc boat ddng Hdn nfla, qua kinh nghiem sfl dung, nhan thay rang lo^ii ren can dan eho lien kit chat hdn vdi xfldng, cd dp dn dinh cao qua trinh sfl dung Hinh Chieu cao phdn day mii dc da true (h, = 3,8 mm, h^ = mm) 3.3 Lfla chon bien dang ren mii 6c va ndp 6c phu h d p , Dang ren gifla nap de vd mu de dfldc Ida chpn la ren he inch (ren TPI-26 vdi bfldc ren p = 0,9423 m m vd gdc ren la 55°), c h l dp ghep difoc chpn la ghep chat Viec chpn dang ren ndy nham han c h l lflc hfldng kinh ldm bung mu 6c siet nap dc va nham dam bao kha nang tfl ham ciia ndp 6c qua trinh sfl dung [4], M O P H O N G t t N G XU" C O HE OC CHAN CUNG Hinh Ren diu vd ren can ddn trin thdn 6c 3.2 Thay ddi hinh dang va kich thflde mat ben mfidc Vdi kit cau dac trflng cua mu de, chiu moment silt tfl nap dc, hai mep cfla mu 6c se chiu udn, dd chuyen vi ldn theo phfldng hfldng kinh se lam tupt ren gifla nap de va mu 6c, kit cau 6c chan cung khdng dam bao ben chat Do do, vdi cd tinh cua vat lieu Titan cd dfldc, qua tinh toan, cac tac gia d l xuat thay ddi hinh dang mat ben mu de ddng thdi tang chilu eao phan day mu 6c nham tang dp cflng chdng uon cho hai mep mu Do nap 6c cd nhiem vu silt chat, co dinh ndi n i n kit cdu ren gifla mu 6c va nSp 6c 6c chdn eung ed cau tao dac trflng, kh6ng the dp dung cac quy trinh tinh toan Idem tra b^n ren thdng thfldng nhfl cd chl tao De md phdng va phan tich flng xfl he dc chan ciingva ndi, cdc tac gia sfl dung phfldng phap phan tfl hflu han vdi sfl hd trd cua chfldng trinh ANSYS [5], [6] Vdi eau tao dae trflng, hai mep trin mu 6c rdt de bi biln dang theo phfldng hfldng kinh chiu moment silt nap dc Theo quy dmh nganh giai phau edt sdng, moment siet nSp dc phdi dat 12 Nra de dam bao he thdng 6c chan cung dfldc ben chat ngfldi benh nhan Anh hfldng cua bien dang ren d i n bien dang mu 6c dfldc khao sdt qua dang ren tfl de tham khio va dang ren de xuat de tai, mdt so kit qua diUJC cho d bang Cac tinh toan d\iac thfle hienv^ vat lieu Titan (Grade 2) vdi module dan hii E' 1,03.10^ MPa, be sd Poisson v = 0,3, dp bendiiy Hmh Hinh ddng mU dc tham khdo cua hdng Striker J = 294 MPa Cde sd lieu cung cap bdi nha cuflg cap vdtliiu [7] (a), GS (b) vd sdn phdm de tdi (c) TAP C H i CO KHi VIET NAM 56 nam 2013 NGHIEN Ctfu-TRAOeOl Bang Kit qud iingxU mU 5c vdi cdc dang ren khdc Dan ren Goc ren Bfldc ren Tam giac deu, 60" 1,2 mm Tam giac vuong 45" 1,3 mm Tam giac vuong 45" 1,4 mm Tam giac can 55" 0,9779 mm (TPl-26) : Ong suat ldn nhdt (MPa) Chuyin vi ldn nhat cua mu oc (mm) Ghi chu 144 135 124 0,41 0,36 0,32 Mo hinh dc tham khao 106 0,23 San pham cua de tai ^ Hmh Kit qud phdn bo iing sudt vd chuyin vi Vdi dang ren TPl-26 dflpc chpn, kit qua md phdng flng suat ldn nhat la 106 MPa, dam bao kit cau b i n vdi he sd an toan k > 2,5 (k = a^J a ) Hdn nfla, kit qua ehuyin vi cho thdy hai mep mu de hi bien d^ng hfldng kinh tdng cpng Id 0,46 mm, gia tri nhd hdn chilu cao ren n i n dam bdo khdng bi tudn ren silt nap 6c S.THifNGHIEM - De dam bao tudi thp cua kit cau qud trinh sfl dung lau dai, nhdm nghien cflu da tiln hdnh thfl nghiem mdi cho kit cdu gom bdn de vd hai ndi [8], [9] Kit cau dflpc eho ehuyin vi cfldng bflc mm vdi chu ky SHz, kit qua cho thay kit cau van dam bdo ben chdc sau 1.000.320 chu ky, cac mdi ghep ren gifla mu 6c va nap dc van dam bdo silt chat, khdng cd ddu hilu tfl thao Khdng ed sii trUpt gifla cac ndi vdi cac mu de vd nap dc (hinh 7) DUa vao cac kit qua tinh toan md phdng, mau thilt ke dc chdn eung dUdc sdn xudt thfl va tiln hdnh thfl nghiem Cd hai loai thfl nghiem dfldc thflc hiln: - Sfl dung trd e\i ehuyin dung silt nap dc cd dinh ndi vdi moment silt de 12 Nm Cac kit qua thfl nghiem cho thdy kit cau 6c khdng hi tudn ren silt, cd the thao lap de ddng (hinh 6) Hmh Kiim tra ren md 6c vdi moment siit 6c 12 Nm ^ TAP CHi C O KHf V I £ T NAM, Sd nam 2013 NGHIEN ctfu - TRAO DOI KET LUAN W-^ J • -1 H" ? ' V f ( ; ^ fflnft Mo hinh thd nghiem moi vd thj chuyen vi I hie qud trinh chiu tdi tudn hodn - Vdi eae k i t qua tinh todn md phdng flng xfl va cac thfl nghiim da thiie hien, ed the thay rang cdc chi tilt dc chan cung dUde thiet kl theo mau cd cai tiln da dam bdo boat ddng tdt vdi cac dilu kien tai trpng dat - Tai trpng dp dat thfl nghiem moi la rdt khac nghiet so vdi thfle te lam viec cua kit cau, cd the kit ludn cae chi tilt vd toan the kit cdu co the lam viec tdt, dam bao dp b i n mdi • - Cdc ket qua cd the ldm ca sd cho cac flng dung lam sdn nghien cflu • Ngay nhdn bdi: 10/5/2013 Ngay phan bien: 10/6/2013 Ngfldi phan biln: PGS, TS Dao Quang Kl, Bd mdn Cdng nghe Cd khi, Khoa Cd - Diln, Trfldng Dai hpe Ndng nghiep Ha Npi Tai lieu tham khao: [1] Hall J E, inventor; 1977 Aug 16 Surgical implant spinal screw United States patent US 4,041,939 ^ [2] Errico et al, inventors; 1997 Sep 23 Polyaxialpedicle screw United States patent US 5,669,911 [3] Kim S.K, inventors; 2007 Jan Screw for fixing spine United States patent US 7,156,850 [4] Nguyen Hflu Loc, (2004), CO sd thiet keMdy, NXB Dai hoc Qu6c gia TP HCM [5] Timoshenko S.P et al, (1970) Theory of Elasticity, McGraw-Hill [6] T Hughes (1987) The Fmite Element Method - Linear Static and Dynamic Finite Element Analysis, Prentice Hall, Englewood Cliffs, New Jersey [7] Aichi Steel Corporation, 2011 Feb 16 Titanium Inspection Certificate H-02-00002 [8] Bruce Boardman, (1990) Fatigue Resistance of Steels, ASM Handbook, Volume 1: Properties and Selection: Irons, Steels, and High-Performance Alloys, ASM International, pp 673-688 [9] Nguyen Van Phai, Nguyin Qudc Viet, (2004) Tinh todn bin moi, NXB Khoa hpc va Ky thudt ^ TAP CHi CO KHi VIET NAM Sd nam 2013 ... Qudc cung da nghiin cflu vd san xuat thfldng mai thdnh cdng oc chan eung, nhiln chdt Ifldng cdn ban e h i va gia cung cdn kha cao so vdi thu nhap trung binh ngudi ddn Viet Nam [1], [2], [3] - Trong. .. thilt ke va che tao dc chan cung lan ddu tiln da va dang dUdc thiic hiln vdi sU chfl tri cfla khoa Cdt sdng A - Benh vi?n Chdn thfldng Chinh hinh I phd Hd Chi Minh, cung phdi hdp vdi trung tdm... Trong pham vi bdi bao nay, cdc tdc gid trinh bdy (Hoa Ky) che tao cdc ndi dung lien quan din van d l tinh toan md phdng, thiet k l va kilm nghiim edc ehi tilu dd d l THIET KE MAU OC C H A N CUNG