CA2190029A1 - Orthopedic prosthesis - Google Patents

Abstract

An improved orthopedic joint prosthesis (10 has a prosthesis body (14) having a first surface (17) for engaging a patient's joint and a second surface (16) for receiving a polymeric liner (15). The second surface (16) is highly polished or mirror-like, for retarding debris generating from the polymer liner (15) and also allows optical pattern inspection.

Description

WO95130389 2 ~ 29 p .,~
The present invention relates to orthopeaic prosthetic ~oint devices for implantation lnto or rOrl ~. of a joint of the human or animal body.
A numher o~ ~lly avOilahle prosthetic d~vicos for ~ nt:~t~nn into a patie3t's ~oint or l~or total joint rorlnl include a tnetallic part and a pla~tics line~ for~ing at lea6t in part, the ~i~.lAr;n~ surface of the joint. For example, in ~S Patent No. 4,a28,s65 thP~re is provided a cotylioaal for a n~- . ~od hip rr~sthoq~q. The _ haa two parts, a tita~u~ hom~rh~r;cl1 shell and a cup of poly~er which is engagea into it.
Other patent8 and patent applications which descrihe acetabular cups include Europ~an Patent l~rrl;~Atinn No. 212,087 pl~hl~qho~ April 3, 19~7, whcrein metallic pina projecC ~rom the surface o~
the cup and contain holes in whlch tissue may grow.
In European Pate~t No. 341,198 pl-hliqho~ November B, 1989, aD ~P~h~ r cup haa a metal outer ahell ~5 and a plastic hody for retaining the hip joint head .
The uae of a - n~ nn of a plastlc-q ll~er and a base member is al90 a feature o~ other joint prosthese6 such as those ~or i l.ln1~;on i~to the sho~lder or k~e One example o~ a ti.bLal prostheis which has a plate or insert forming an SU~$71TU7E SHEE7 (RULE 26) 21 9G0~9 Wo 9sl30389 r~"8~ . 7L~
~rticulatlng Gurf~ce for the joint is rl~y~lhc~
US Patcnt No. 4462120.
The present invention Frovldes an improved orthop~dic ~oint prosthesis wherel~ the prosthesis body has a b~e me~er (e.g. tray, cup or Rhell)and a polymeric liner~ The pol~eric liner affixes to the prosthesis body and provides an artl~t;n3 s;urface ~or er:gaging a~other rrnRfh~Ri~ member.
~0 The prosthesl3 body ha~ a non-art~ t;
mirrored or polished _ur~ace that receive6 th~
plastlc lin~r. Thls surface ha~ a poli_hed surface that faces the 11ner for ret~rding liner 1~ dehri6 ~n~rat~n The pollshed surface has a ~uyl~ o~ preferably les~ than eight ta) mlcro-inches .
The ~ n~l lo~n o~ th~ polymeric liner and orthopedic bas~ with mirrored or poli~hed surface ~ini8h provldes numsrous adv ' _ . Fir~t, it pr~rides a low frictio~ and low abrasion surface for ~ ntr;h~ n~ the contact force~ between the polyethylene li~er ~e.g., ~1HNWPi~) and th~l rrnRth~ body shell mis reduc~s the abr_sive gr-l~r~ n of polyethylene debris resulting ~rom motlon between th~s liner atld the body.
This motion may cone from a varlety of ; which i~clud2 Poi~son volum~tric di3tortlon of the poly~thylene resulting in WO 951tO389 lnr~l t~7ed q~TAnn;nn and cnnt~tnr~ of the sur~;~ce of thc liner agalnst the body ao ;~ re6ult of loading the liner, a~d thc mi~ tnn which occurs f~om ~orces ~rom a liner within an~ Oround 5 the confineo of thc prostheOis body interior. Por example, in tke CEI8e of an A~tAh~ r ~rnrth~ n, the femoral head is loadcd at the liner.
rlicro-motio~ c~n occur in hip 1 t.h~oA~R ~rom 10 forces g~n~rAtq-l by the ~emoral head pushlng the liner within a~d around the confines of the proothesis body, namely an acetabular Qlp hody with a concave polished surf~ce that receiveo the liner.
Mlcro-motlon can occur in a knee ~ oLL~._18 _o a 15 tiblal tray llner recevea i'orce gqnor~t~td by a femoral rrnth~n;q. A shoulder or glenoid also has ~orce transmitted at the joint to a plAstic liner of the glenoid metallic The mirror finl~h Al GO allows the us~ of optical non-contact in~E~e~ttnn of the interior of the metallic _ 8urface for checking the ~ J~ L of the ~ -. Thc use of norl-contact optical ;nRI~ectton methods allow complete checking of whole two and three ~'t~ innJ'l surfaceo at one time. The usual method of optical three-~li ~nn~l tn~p~ct~nn is to prbject a regulisr pattern of light onto the suriace which i8 to be inqp~rte~ The reOultant two ~t; lnnAl proje~tion of the scene may be u8ed to give highly accurate total ourfacc ~

WO9~/30389 21 90Q~q PCr/US95/05710 .

Diatortions in the regular pattern indicate distortions in the part surface and i~dicate deYlations from the desired part geometry~ Thls 5 method i8 in~fferl-lye on highly smooth ~urface3 ~ince the projected light of the regular pattern bounce~ o~_ th~ - - r ~ ' target and no two ~li ~; nn-l mapplng is pos~ible . In thitt devlce the h,ighly fimooth surfac~ is ~urther poli6hed to 10 act a~ a re~lectiYe mirror. Thi~ ~urface mirror then iB used aa a lens to view a two~ nn511 pat~ern such a~ ~ grid drawn on a white sheet of papcr or a serie~t o~ c ~i~gs. Distortion~
in the Y~ewed image then are a re~ult o~
15 dlstortion~ o~ tbe lenfl and hence the surface which i~ desired to be mea5ured. It i~ thereby po6slble to ~ nspect the highly smooth sur_ace o~ the prosthe~ig body due to this pnl; F:h~nrJ, Th~ met~od of; , ~' i nn may be both by trained huloan inRrectora and by image analysi~ t' by c~rt~rtn~ the reflected image by a Yldeo camera, digitlzing the image, and using computer analy~ia to measure tho amount o~ deviatio~ of the pattern from the allowed sur~ace geometry t~ nrc~.
The adva..l,-,y~s o~ thi~ ~mooth ~nd poli~hed sur~ace is theref ore to provide non - contact, and therefore non-destructive (~on-~irr~trll;ng), 30 measurement of the interior of an ~ h~llwr device. Th~ ;n~p~ctinn methods ~equire a surface Wo g~l30389 2 ~ 9 0 0 29 ~ o ~hich allows ~ reflective re~ t~nr 6~ff;rif~nt to provide adequate re~lectlve image ~uality for analyais. Current ;n~pe~r~;nn limits requirc a surface finish of les6 than eight (8) micro-lnches to ~ t;~:h thia r~u~tity of r~c~ntl~ti~n-In one . ` ~ , th~ present inventionprovides an improved aret~ r prosthesis. For an ~IratAhlll:zr pro3thesis, ~n ~r~t~hl-lAr cup body 10 pre~erably include~ openinga therethrough which can funotion as drill guides for the sUrgeon after the cup has been ~laced in the patient'g ~re~A~
A sccond . ' `'-- of the invention 18 a 1~ glenoid pro~the~i~ for; _lpnt::lt;~n into a shoulder .
A further ' -~' of the invention m~y be a knee r~3thA-i~ fiuch as tho~e generally used for ZO eot~l l=ee r~ Dt-.

89 ~ 0 ;2 9 PCTIUS95/0571 Tl~ n~ l OF 1!~ DR~
For ~ Surt~er ~ d~ ,~dlng cr thc naturc and ob~ct or the prasent invcntion, rcrencc should oe b~d to tho rollowing detallod ~cscription ttlccn in con~unction wlth the ,~lng drllwings, in which likc parts l~ro giv n llke rerQrence nu~Qrals, ~nd whcrQin FIG~RE 1 13 ~ ~ld~ scctional vi~w oS thQ ~.~L~
' ' ~ or the ~pparatUs Or thc pre--nt inYention sho~lng ~n D_e~ h~ nr cup;
PIG~RE 2 ls a sldc ~ection~l view Or the prer~rrcd ' ,t'' l of th~ Or the present inv~ntlon sl~Owing ~n ~91 ~h~ll~r cup;
PIGllRI~ J i~ an cxploded p rspcotlve view or th~ L~.,.
Or the ~ r~ o~ the pr~sQnt invention showing n ~ h - l ~ r cup;
CC~ q is ~ top viow or the prefcrrcd ~A' ' Or thQ
~ppar~tus oS the ~rQaert invention showing ~ glenoid co~ponent;
FIC~RF 5 ls ~ botto~ vlow Or thc L"~''~ J - ' ~ Or th ~pp~r~tus Or thc present inventlon showing ~ glonoid E~G~RE 6 is ~n olcv~tional vicw o~ tho prefarrlad . .A~ t or the appar~tu~ Or the pre~ent lnvQntion ahol,ring ~I glenoid oo~ponont;
2~ FIG~IRF ~ ls ~ ~id~ vl~w Or th- I ,cr.~ ' ' o~
~he ~ppsr~tUs Or the prasent invontion _howing ~ gl~noid co~ponsnt FIG~ a ~s a bottoD~ view oS tha ~ rCL~ ' ' `' Or '~he appar~tus or thc present lnventlon showing a tlbi~l 3 0 co~ponent;

wogsl30389 21q~2~ P~ o F~GL1R}~ ~ is an ~lcvational vlew Or tbc pre~err¢d '~ ~ of th~ appar~tus of th- pre8ent lnY ntion taken ~long llnes 9-9 if rigurc 8, ~howing ~ tibi~l oo~lpon~nt;
FICI~RE 10 is ~ aeo'cionnl view taken ~long lineG 10 - 10 5 Or Pigure 8;
PIG~IR} ll is an el-vation~l view Or the prQrerred ' ' ' Or th~ app~r~tua Or th- prc~ent invention ahowlng tibi~
FIGUi~E 12 15 ~ ~idQ view Or the pr~ r~rred ' '' Or the ~pp~ratus Or the present inv ntion ~howing ~n h.~ ' 'C
tibial co~ponent;
FIGURE 13 is ~ top Vi-Y Or thc prererrcd ' '~ Or the ~ppar~tua oS th~ pr~s nt invention ~bow~ng nn ~ r tibi~l qlenola { , ';
lS FIGURE 14 is an ~ rrl~l view cS the prererred o~ the apparatus o~ the prQS nt invention showing ~n ~y ~ ' r eibial - '; and FIGTIRE 15 ls a bottcll vl~w of the pr~ferred ' ' ' ' or the ~pp~r~tus of th~ present inv~ntion sho rin~ ~n ~syr~etric tibi~
FIC~RE 16 i~ ~ ache~tic ~li~gra~ Or the grid u~-d to inspcct th- polished surr~c~ rOr di5tortionst F~Gt~RE 17 is ~ s-cond ' Or a test grid p~ttQrn used to inspQCt the hiqhly polished sUrr~eQ portion Or th~
~r~ - CUp prosthcsil Or the pre2~nt i, ~ nn;
FIGUR~ l~ ls ~ di~gr~ of ~ teat grld showing r o surf ace dcrects; and FIG~E lg is sche~ati~ ~isgr~ showing loc~l d-fects for ~ pollshed ~urfscc that h~ been inspect¢~l uslng thc grid W09~l30389 2 ~ ~0~2~ P~u~ o In F~ 1 th~rQ can bo ~en a ~ctional vlQw Or tbe rirst ~ ~nl cr thQ ~ppar~tu_ Or the pressnt $nvention ~l~e~51n~ g~nerally by thc nun-ral 10 In PIGOR~ 1, thsre c~ be seen ~ hip ~L~ ~ber 11 ~cunted in a re3ur 12 Or A p~tient The hip prosthe5i5 11 inclu~c an upper b~ll portion 1~ tbat reglstor3 with tb- r-e~ Ar app_r_tus lo or th~ pressnt inVention Th- -c~3tAh~ r ~ 10 inclUdQ~ a cup or shell pro th~sis body 14, prerably or 2 met llic material witb a plastlo llner 15 portion The n~t_llic cup body 14 incl~d~c An inner conoAYe ~urracs 16 _nd an out conYex ur~ace 17 Tbo ~ur~acos 16, 17 ar~ cpAc-~ apar'c, ~lerinlng tho thickn~ss Or the cup or sholl 14 Th~ cup body 14 crn pro-ldo a thr~e-~ n-~ ~ur~ac~ ; ' thAt iS sintered to the outsidc -ur~Ace 17 (such as sintsrsd ~tal beAds) The surface 17 can bs rachined arter sintoring Another type Or rougheneC outor surr_c~ ~7 could bQ proviaed ~uch a~ pla~a sprayed m~tal, pla~a sprayed hydroxyl npatite, or a - ~Ally texturod or roughoned surSacs Th~ ~hsll or cup body 14 could ha~Q ~m xterior curr~¢o 17 optimized ~or use with bone ce~ent A plur~lity Or openingg 18 in on~ or prsrcrably clongate~l boros extend botwoon th~ inn r conc~re surSaco 16 ~ml th~l outer conYex surrac~ 17 ThesQ openlnys are in th~
ror~ Or bores having a bore ~11 19 The opsning~ 18 can unction ~Y drill guiaes ~or the surgeon , once the mct_llic cup body 14 portion Or the A~-et-l.h..l :~r cup procth~io 10 ls placsd ln pocition in the patient~s ~t~ as sho~n in F~GU~l!; 1, ths ourgQon can simply drill throuyh any ons Or ~O tho plurality or bores rorming an opening in the underlying bone tissus dR~l~AtR~l gooer lly be the nurer_l 20 W0951303Qv9 2 ~ 9~029 r~-~u~
_ 9 _ When tho surqeon places th- oup body 14 in th~ position ~ho~n in Figure l, the plurality cf bor~ 18 can nct as drill r,uide rOr the surgeon The borc 19 walls of each oponing 18 can h~ 6h~pl/d to d~rin~ ~ gul~e rOr a CVLL~ n~1Y
s shaped ~nd ~i~ed drill opening5 18 allow the sUrgcon to rOr3 urgical openings ~n th~ Underlying bone tl~su~l 20 A JQlected ~urgic~lly rormed op~ning 18 is then occupled by ~ peg tcnd not necQ~sarily ~ch ~pen~ng 18), sUch aL one Or the pcgs 25 - 28, a~ s-en in Pigure l In the p~r"L,~
~ ~, eac21 of th~ pugs 25 - Z8 extends $nto tho bone tl~-u~ ~t n dLrre~snt angular poQltion with respect to th-other pegs to proYid~ ~ rigid nchor rOr the cup 14 Pegs zS-z8 c~n be polymer, ~ctal, or reFnrh~hl~ poly3 r In l'igur~ ~, cup _ody 14 is ~ecured with ~ plurclity Or bonQ screws 30-33 Each bon~ scrc~r has a ~L~I~L. ~ iCal soction 34 t~t rorms a wedg~-lock or t~p r lock rn~ rt~ n~ with a L., LL~ ical openlng or bore 3 5 in cup body 14 when the threaded shank 3 6 Or each bon~ ~cre~ 30-33 rully eng~ges underlying bone tiscuo Zo .
Cup body 12 i3 prer r~bly ~ctallio having an annul~r b~
38 thct de~ines a plcnQ ~e~ Pigu~e 3~ Th~ cup body 12 conc~v~ ~urrccQ 16 is a ~hiny pollshed surrllce that fcces thQ
convex surracQ 39 of polymeric liner 15 The polish~ concav-iur~l~ce 16 h~s ~ ~ _ Or l-ss thcn ~lxteen ~16~ llicro-zs lnches, cnd pref~r~bly 1-~ than eight (8) ~icro-inches Such a highly polished sUrr~C~ 16 apPears llirro~-like The poli~h~d conczve surraco 16 inhibits poly~r l~ner debris g~nerctlon ~iner lS has ~n inncr concsv~l surr~ce 40 th t r~ceives fe~ur bcll portlon 13 during use (6ee Figures l and 2) Figurus 4-7, the pr~i~erred ~ nt of the ~pparatus oi' the present invQntion lo i5 sho;~n in the for~ or a glenoid _ _ _ _ _ W0 9'i/30389 r~ o 2 1 ~0029 prosthesis, ~he slOnoid r rr~ h.. e~ 10 includes ~ r t 41 that can cooperate with ~ humeral coDponent (not shown) The use Or glenoid 1~ pnrt Or a tot~l shoulder ~yste~
can be neen for ~xaDple in Smith ~ Nephew RicbArcs~ r ~bl i O~t l t~n s entitled "Cofield Tot~l Should~lr Sy~teD 5urslcal Te~hn; ~, ~nd ln U S P~tent 5,108,396, i~ L~ od h~r~in by rerer-nce ThQ qlenoid coDponent 41 has A bone insrowth ~ur~ce 42 th~t can bo, rOr ~aDpl~, a plurality of ~otsllic ~intered b~d- 43 30n~ ingrowth ~urr~co 42 is attnchOd to th~ p~tiont's bon~ tissue wlth bone C~Dent ~md screws ror exaDpl~ ns d~scribed Dore ~ully in the Co~i~ld Total shoulder Syste~ sursical ~ '~_- Qnd in IJ S i?~tont 5,1~,396 Sur~co 44 i& ~I nirror ~urr~ce th~t r~coiveo n polyethyleno or lilco insQrt that pro~ide8 On ~i ..-~ q &urfacs rOr arttr~A~ q lrlth n huneral Thus, th~
Dirror urrace 44 is A non~ ng surr~ce thrlt enq~gen th- rear or non-ar~ tin~ surracQ er the polyethyl~ne in3ert The glenoid , ~ can includO a ~t~m 4s and eylindric~l hcllcw l~ev s 46 th~t ~ ' bons 6crO~&
AnnulAr ~hould r 47 projeot3 ~Yay ~ror~ nlrror sur~Ace 44, definlng a structUre that e~n hold th~ polyethylen~ lnz rt ourin~ use In Figures 8-11, the pra~OrrOd ~ 10 of the App~ratus of the present inventicn ic &hown ln th~ form o~ a tibial prosthe~3is The tibial LJLooi ~ is 10 includOs a tiblAl conponent 48 having A ste~ 49 thAt oeeupies a eurclcally ~crmc~d opening in the p~tiOnt'~ tiblA Th~ di3t~1 ~ld~ o~
tr~y Sl registO~s against th- patlent's proxiDAl tibia, once 3urgicAlly shnped to recelve ti~i~l , 48 Ti~ial conponent 48 has ~ nirror 6urrace 50 that receivec polymeric incert 5Z ~see l!igure 1~ Mirror surrace 5~ $s providcd on the proxlnal side of tray 51 Wo95/30389 - 11 - 2 ~ 9 0 Q29 P~ , _J/-O
During use, poly3eric in ert 52 artlcnlates Yith ~emoral 53 Femor~l 53 is attached to the patient's ~e~ur 54 (as shown in Fiqure 11), nr~t- lR~ng ng~lnst polymerlc lnsert 52 th~t ls supported upon the mlrror curr~ce 50 surrnce 50 ls the proximnl ~urr~oc o~ tray 51 TllUs, thQ r~irror surrnCQ ls a non-Ar~ lRti"q surrace that enqag-s thc r~r or dlstAl sUrrace Or the polymeric in~ert 52 The proxi~l sUr~rc~L o~ polymerlc ~n~rt 52 1~ an art~ a surS~cQ th~t r~c~iv-~ ~ poll~h-d m~tallic ~irT lAtinq sur~cc o~ ~emor~l ccmponent 53 In Plqures 12-15, the ~, re~ ' ' lO Or the Apparatus Or the prcsent invention is Ghown in the rOrm Or an ~ n tibial ~ P..~ 10 lnclud~s ~n asl n tlbial c~sponent 56 thnt hnl ~ bone e;n~aging ~uri'~ce 57 that enqages he proxlDlal, curqically prepnred wr~ce o~ thC p~t~ent ~ ~ tibi~ The oppo~ing aurr~ce ~rom bon~ engaginq sUr~ce 57 is A proxinal, ~irror ~urrAc~ sa thnt r~c~iv~s a polyneric insert ~not shown) Peripher~l ~hculder r;g and mirror sUr~ace 5ri derine non-art~ lntinq urraces thst r~c~lve the poly~ceric insert, much in th- ~nm~ fnshion tb~t polynQric inA~rt 52 ls held wlth trny 51 nt surrace 50 An op ning 60 ~llows tlbinl 56 to be AttaCh~d to ~c pati~nt's tibia Using a bone scroW, l~or exallpl~
~t should be ~ (1 th~lt the _ L or a polyQthyl n- or polymerlc ins~rt to a tlbinl component (~uch 81~ tray 51 ), or to ~n a~ ~ tibial compon mt (such a~
compon~nt 56) i6 per ~ lcnoYn ~n th~ ~rt Such ln~l~rtc ~re shown and described in the smith ~ Nephew R1Chards p~hl~ tir~n entltl~d n~ enesis ~otal Xn~Q System Surgical Technique"
~0 pu~llshed ln ls92 and lr ~ AL-i hereln by L~r~.,.. ~
nowever, the present lnventlon proYlde~ ~n i ~ th t ~e~tures a rirror surr2ce portion ln nRti~n Ylth ~
_ _ _ _ _ _ _ WO 95130389 ~1 9 e~ (~29 PC~ J/10 .

polyD~eric in~ort as af.,LG' '~ 2s part Or An prosthesis 10 Fisur~s 16-19 qrid eharts 200, 20~ that ean be cr2Yn on a ~rhlt~ ~h~-t Or p~per rOr QxD3ple nd u8ed to lnspect the highly poll~hed innQr coneavQ surface 16)0f ~cetah~lA eup body 14 ror deroct6 In Flgure 16, n e,rid Z00 is in the forD
cr 2 plurality ~r concontrie rinqs 201, 202, 203, etc A
c ntrsl o2ening Z04 allovs tho u~Der to vi~ually in3p~ct the ln~ldD surraee 16 Or th~ oup body 14 uhen the rlat lJrid 200 iD
pl~eed on top Or the eup body 14 with th- print of chart 200 raclng the nirror like polish~d concavu gu~sce 16 In thi~
ra~hionl the user si~ply vl-Ys tho lin~d pattern Or the C~rRn1~r~ r1n5~ Z01-203 Or srid chart 200 a~ rP1'lec~l orr th~ r~irror ~urrsee Or the in ~ido, conesvo Isur~sce 16 Or thQ
oup body 14 In Pisure 17, ~ generslly rPc~n~ rly Ghaped te6t srid 20~ is shown In Flqure 18, a rerlectivo psttern ~or the tost sria 205 is sho~n as patt rn 206, showing no derects In ~igure 19, another tnst qrid p~tt~rn r-rl~ctlon 207 is shown th~t not~s two local derects z08, 209 Figur~ 16 illustrst~ thod of ~ , ' ^- that ~sy bo usea by tr~in~d hu~ n ~~, ' , ~imply looking through the c ntral opening 204 When such hu~sn insr~c~ion is ~rployed, the inspector si~ply looks through tho openlng Z04 uhQn the 2!i grid ehart 200, 205 16 plseQd sgsinst ths eonc~v- 16 sidu o~
hlll ~-- eup body 14 another m-thod of; , ~ ~sy bo by imaqQ snsly-1 Perror~Qd by capturing the re~lected ir~age wlth 2 vldclo ~amera, ~t~ ng the l~nage and u~ing co~puter analysis to Deasure the 22l0unt of devi2tion Or the pattern ~ro~ the allow~d surrsce g~o lletry tolers"eo ~hu3, the surr~ce 16 dQrine6 a ~irrer that 15 used ~s a lerls te vle~f a two WO9S130389 ~1 9002~ O

n~ll pattern such as the grld p~ttorns ~00, 2C5 drawn ~Dr eYa Dple on 4 ~hlte shuE t of p~per Dlstortion~ in the VieYQd iDmqe 4re thon a rosult of distDrtions Or the lon3 ~ur ncc 16 ~nd henc- th- surf ~ce which 1~ desired to be 5 ~ea~ured The ~ollowinq ~4blo 1 llst~i p4rt numb-rs ~nd ,,-~c_"v ~lng p4rt descrlptions as used herein ~nd in th~
drAwingL
~AB}.~! 1 - PI~S IIS~
P~`~ P~ P~
~oint r t~ h~q1~
11 hip prosthosis ~enhor 12 re~ur 13 b411 portion 14 cup hody pla~tic lin 16 innor conc~v~ surr4ce 17 outer convex surr~c-18 openins~
19 bor~ w~ll hon~ tls~u~
25-28 pegs 30-33 bone scr-u~
34 ~ lc~l portion r . L~ bore 3C thro~ded d~ank 3 8 annul~r b4su 3 9 liner con~reY surf ~ce liner conc4ve sur~ace 41 glonola corlpon~nt ~2 bon~ inqrowth surrac~
~ 3 m-t411ic boad~
44 mirror surraco ~5 stem 46 hollow hULhinq 47 ~nnul~r ~houlder ~e tibi41 colzponent 49 ste~
So mirror sUr~ce 51 trny W09SB0389 2 1 90029 r~.,L~ ~ rlO
.

52 polymQric insert 53 fcnoral co~ponent 54 rcnur ss tibi~
56 asymmetric tlbiP~l co~ponent 57 bone Imgaging surrac~
58 nirror surracQ
r r ~I~'A 1 should~r op_nlng 200 circular grld pattern dart ~01 concentric ring 202 ~ ntr~-~ rlng 203 concontric ring 204 c~rtr_l opcning 205 r~tA~ P~ ~rld p~ttern chArt 206 r~rl~ctlvQ pattcrn - test grid ~07 rcrloctive pattQrs - tQst grid 20~ de~oct 209 de~ect ~GCaUs~ n_ny varying and dirfer ~nt ~ t~ nay be s~de withLn the ccope or tbe invent~v~ conc~pt herein taught, cnd bocau~e n~ny r~ A~ e nay b- nade ln tho ` ' ' h~r~ln detailed in ..~ ,lA..~.~ uith thQ degcriptive ro~ i o~ th~ l~w, ~t is to be ~ L o~ that th d tail~ herein are to b~ ~ L~ And nct ih ~ ~iritlng en Q
~hat is clai~cd as invention is

Claims

Claims 1. An orthopedic joint prosthesis comprising:
a) a prosthesis body having a first body surface for engaging a patient's joint and second body surface, and b) a polymeric liner that lines the prosthesis body at the second surface during use, the liner having first and second surfaces, the second surface defining an articulating surface that is positioned to receive and articulate with a separate joint prosthesis articulating member, the first side of the liner defining a non-articulating surface that is positioned on the opposite side of the liner from the second surface; characterised in that said body surface of the prosthesis body has a polished surface.
2. An orthopedic joint prosthesis according to claim 1; wherein said polished surface has a roughness of less than eight microinches.
3. The orthopedic joint prosthesis of claim 1 or claim 2 wherein the polished inner surface has a roughness of less than four (4) microinches.
4. The orthopedic joint prosthesis of any of claims 1-3 wherein the polished inner surface has a roughness of between one (1) and four (4) microinches.
5, An orthopedic joint prosthesis according to any of claims 1 to 4, wherein said polished surface is mirror-like.

6. The orthopedic joint prosthesis of claim 5 further comprising grid means for inspecting the polished inner surface for defects.
7. The orthopedic joint prosthesis of claim 6 wherein the grid means is a grid comprised of a plurality of concentric rings.
8. The orthopedic joint prosthesis of either claim 6 or claim 7 wherein the surface mirror defines a lens to view the grid.
9. An orthopedic joint prosthesis according to any of the preceding claims, wherein said polymeric liner comprises polyethylene.
10. An orthopedic joint prosthesis according to any of the preceding claims, wherein said prosthesis is an acetabular cup body prosthesis.
11. An orthopedic joint prosthesis according to any of claims 1-9 wherein said prosthesis is a glenoid prosthesis.
12. An orthopedic joint prosthesis according to claim 11, wherein said glenoid prosthesis comprises a glenoid component including a stem and cylindrical hollow sleeves for accommodating bone screws.
13. An orthopedic joint prosthesis according to any of claims 1-9, wherein said prosthesis is a tibial prosthesis.
14. An orthopedic prosthesis according to claim 13, wherein said tibial prosthesis comprises a tibial component having a stem for implantation into a tibia and a tray attached to the stem, said polished surface being provided on the tray.
15. An orthopedic prosthesis according to either claim 13 or claim 14, wherein said tibial prosthesis is an asymmetric tibial prosthesis.
6. An orthopedic joint prosthesis according to any of the preceding claims further comprising means for connecting the liner to the prosthesis body such that the non-articulating surface of said liner is adjacent to and in contact with the polished second body surface of the prosthesis body.
17. An orthopedic prosthesis according to claim 16, wherein said means comprises an annular shoulder which projects away from the mirror surface and defines a structure which holds the polymeric insert during use, 18. An orthopedic prosthesis according to claim 16, wherein said means comprise projections on a surface of either the polymeric liner or said non articulating surface which may engage in complementary grooves in the other surface.
19. An orthopedic prosthesis according to claim 16, wherein said means comprises a peripheral shoulder adjacent to said polished surface.