patellar cartilage

8/13/2019 Patellar cartilage

1/19

C H O N D R O M A L A C IA O F T H E P A T E L L AP H IL IP W IL is, P . S . A N D R E W S an d M . B . D E V A S , L O N D O N , E N G L A N D

F rom the M idd le se x H o sp ita l a nd the la nd S u tton In s titu te o f P a th o log y

C ho ndrom alac ia is a p recu rso r o f os teo arth r itis . I t c an , pe rh ap s, b e reg arded as an ea rlysenescen ce (th e chan ges in th e in te rv er teb ral d iscs tha t beg in during the second decade of lifea re o ften so desc r ibed ) bu t m uch m o re m u st b e lea rn t abou t the chem istry o f p ro te in s an dpo lysacchar ides be fo re such an idea can be accep ted . T h e a rticu la r ca rtilage o f the p a tellais inv o lved ea rlie r and m o re constan tly than a lm o st any o the r jo in t su rface. T he processo ften b eg ins d uring th e secon d decade o f life , an d b y th e ag e of th irty nea rly ev eryo ne isaffec ted . I t is , how eve r, in o n ly a few in d iv id ua ls th at the changes cause sym p tom s , an d infew er s till th at th ey prog re ss to o steo a rth r itis . T he late stage , osteoa rth ritis , ha s b een fam ilia rfo r cen tu rie s . D esc r ip tion s o f th e ea rly p hase s a re com para tive ly recen t, an d even thou gh ac lin ica l d iag nos is o f cho ndrom alac ia o f the p ate lla can no w be m ad e w ith som e prec isio n ,the co nd itio n has receiv ed b u t scan t a tten tio n in th e lite ra tu re o f B ritish an d A m ericancoun tr ies .

C red it fo r the firs t accou n t is g en e ra lly g iven to B u d ing er (190 6 , 1 90 8) w h o d escr ibedfissu res occu rr ing in the a r ticu lar ca r tilag e o f th e k nee , usu ally th e pa te lla , w h ich h e co nsid eredto be traum a tic in o rig in . H e o pe ra ted on fif te en pa tien ts , rem ov ing the a ffec ted ca r tilag ein th ir teen w ith re su lts tha t w e re , in th e m a in , s atisfacto ry . L u d lo ff in 19 10 p ub lished o necase in w h ich h e exc ised alm ost a ll the ca rtilage co ve rin g th e pa te lla , an d A xhausen (1 919 )rep o rted ano th er in w h ich he had rem oved p art o f the ca r tilag e six y ea rs p rev io usly w ith ag ood re su lt. In 192 5 L { 228 }w enrepo rted the resu lts in th irte en op era tions and a lso tha t he hadfoun d s im ila r ch an ges in tw en ty -six n ec rops ies o u t o f fo r ty -fou r. T he te rm ch ond rom a lac iaseem s to have been in trodu ced by A lem an (192 8) w ho foun d d eg en era tion o f the a rticu la rca rtilage o f th e pa te lla in one -th ird o f 2 20 k nees o n w hich he had op era ted , and in tw en tyth is w as the o n ly le sio n . T h ere w ere seve ra l fu rth er rep o rts du ring th e nex t few yea rs , andin 1 936 {2 48} w repub lished an ex ten sive su rvey g iv in g the re su lts o f a pa in stak ing c lin ical an dpa tho lo g ical investiga tio n , an d h is f ind ings in th irte en op e ra tions . C hak lin (1 939 ) s tated tha the had rem ov ed the a r ticu la r ca rtilage o f the p ate lla th ir ty -e igh t tim es, b u t gave no d e tailso f th e re su lts . In 19 40 K arlson rep orted th e re su lts o f ope ratio ns carr ied ou t in A lem ansc lin ic , an d a lso th e sub seq uen t beh av iou r o f seven ty -o ne kn ees n o t sub jec ted to o pe ra tion .W ibe rg (1 941 ) investig ated the e tio lo gy w ith sp ec ia l refe rence to th e co ngru ity o f the jo in tsu rfaces , and H irsch (19 44) rep o rted ce r tain p hys ico -chem ica l inv es tig a tions an d fo rty -o neoperat ions; S o to -H all (194 5) treated six so ld iers b y excision o f th e pa te lla , and C ave , R ow ean d Y ee (1 945 ) rep o rted eleven m o re in w ho m they h ad rem ov ed the ca rtilage . In 1 948G ray gav e a sum m ary of the m o rb id ana tom y an d c lin ica l f ind in gs and reported e igh t p atien tstreated by exc ision of the pa te lla w ith goo d re su lts . T h e to tal num ber o f o pe ra tion s repo rtedis m ore th an 200 .

I N C I D E N C ET h e firs t m ic rosco p ic chang e in th e a r ticu lar ca r tilag e is absence o f th e n orm a l

m e tach rom as ia. T h e ea rlies t m acrosco p ic chang e is sw ellin g and so ften ing of the ca rtilage -o ften m isnam ed oed em a-w hich is p re sen t in a t lea st f ive ou t o f six peop le b y the ag e ofth irty . T he nex t stage is f issu r ing an d flak ing (F ig . 2 ) , an d th is can be foun d in m o re th an* A p a r t of th is p ap e r wa s re ad b y on e o f u s (P . W .) a t the A n nua l M ee ting o f the C anad ian O rth opaed icA ssoc ia tion on June 28 , 19 55 .V O L . 38 B, NO 1, FEBRU RY 195 6 95


2/19

96 T H O M A S F A IR B A N K B IR T H D A Y V O L U M Eha lf th e p opu la tion by th ir ty , the inc iden ce inc rea sin g stead ily the rea fte r . T he fig u res ob tain edby {2 48} w re1 936 ) at pos t-m o rtem exam ina tion a re sho w n in T ab le I.

T he frequ en cy w ith w hich fissu rin g o f the a rticu la r su rface o f th e pa tella is fou nd a topera t ion fo r rem o va l o f a sem ilu na r ca r tilag e is som ew ha t le ss than these fig u res su ggest,pe rh ap s b ecause o f the re str icted v iew av ailab le . T h e sev erity o f f issu rin g canno t read ily bereco rded sta tis tic ally b ecause estim a tion is a m a tter o f pe rsona l jud gm en t. O w re d id no tfin d a t necrop sy any exam p le und e r the ag e o f th ir ty tha t h e cou ld c las sify a s seve re , bu t the re

T A B L E IIN C ID E N C E O F C H O N D R O M A L A C IA O F T H E P A T E L L A IN I 24 N E CR OP S IE S ( { 21 6}w R E)

A ge N um berof O ed em a Fissur ing1 4-1 9 1 8 5 -20 -29 32 2 7 183 0-39 26 2 4 1940-59 32 3 0 2 960-80 16 16 15

w ere n ine be tw een th ir ty and th ir ty -n ine , an d fo rty ov er th e age o f fo rty . T hese f ind ings a reno t in co m ple te acco rd w ith c lin ical expe rien ce . T he com m onest age fo r sy m pto m s to ar iseis be tw een tw en ty an d th ir ty , and w e have o ften foun d ad vanced changes a t op era tion onpa tien ts o f th is age an d , in deed , in yo ung er peop le . T he d isc rep an cy is p robab ly ex p la inedby the na tu ral s elec tion o f th ose attend ing fo r c lin ical exam ina tion of the k nee .

It is d ifficu lt to es tim a te ho w often ch ond ro m a lac ia g ive s r ise to sy m pto m s bu t it is c lea rtha t th e c lin ica l d iagno sis becom es m ore com m on as aw areness o f the cond ition inc rea se s;an d it is m ore o ften seen a t o pe ra tion w hen it is de libe rate ly sou gh t. S om e idea o f th ein cid en ce is g iven by co m parin g the freq uency w ith w hich cho ndrom alac ia w ith m arkedfissu ring h as b een obse rved a t o pe ra tio n w ith the n um b er o f m en iscec to m ies p e rfo rm edduring th e sam e pe riod . T h e figu re s fo r the M id d le sex H o sp ita l, inc lud ing chon drom a laciaencou n te red during m en iscecto m y , are sho w n in T ab le II .

T A B L E IIIN C ID E N C E O F C H O N D R O M A L A C IA O F T H E P A T E L L A A S S E E N A T O P E R A T IO N R E L A T E D T O T H E N U M B E R

O F M E N IS C E C T O M IE S P E R F O R M E D D U R IN G T H E S E P E R IO D (M ID D L E S E X H O S P IT A L )

19 50 19 51 195 2 195 3 1 954 Jan ./June T o ta lC hon drom a lac ia 4 2 8 5 2 2 7 48M eniscec to m y 31 24 3 7 29 32 13 1 66

N A T U R A L H I S T O R YT he n atu ra l evo lu tion of chon dro m a lacia canno t read ily b e fo llow ed because th e p recise

con d ition o f the ca rtilage can no t b e estim a ted w ith accu racy by clin ica l exam ina tion a lon e;and w hen the re a re sym ptom s seve re enou gh to ca ll fo r ope ratio n , the a ffec ted ca rtilage(o r the p ate lla ) is g en era lly rem ov ed an d its sub sequen t b eh av iou r can no t be o bse rv ed .

N early all ad u lt k nees show so m e o f the pa tho log ica l ch anges o f ch ond ro m a lac ia , bu tth ese a re g en e ra lly re str ic ted to a sm a ll pa rt o f th e pa tella . P ro g res s , in a la rg e m ajo rity , is

TH E JO U R N A L O F B O N E A N D JO IN T S U R G E R Y


3/19

F I G . I F IG . 2Figu re 1-E ros ion o f the lo w er and inn er quadran t su rrou nded by areas of nodu la r sw ellin g andfissu ring , and cov ered w ith pannus . A s seen a t opera tio n M ay 195 5. F igure 2-E ro sio n of the low e rand in ne r qu ad ran t w ith f issu rin g abo ve , a nd a lso f issu rin g of th e lo w e r a nd o ute r q ua dra nt. P ann usis sp read ing o ver the low er bord er. C ase 40 .

F I G . 3 F I G . 4F ig ure 3-T he w hole surface of the pa te lla is dis in tegratin g . Pa tella exc ise d Jun e 1 95 5. F igu re 4-E arlyo ste oar thri tis. T he art icu lar cart ilag e of th e p atel la and the inn er c ond yle o f the fem ur ha s b ee n she d.A s seen a t ope ratio n a fter ex cisio n of the pa tella O cto be r 1954 .

lI t { 149}

{149} {1 49}

F I G . 5 F IG . 6F ig ure 5 -A d va nce d o ste oar thr itis w ith a larg e m a rginal oste op hyte an d ve rtic al sc oring . F igu re 6-Sam e pa tien t as F ig ure 5 sh ow ing ve rtic al sc oring o f fem u r. A s see n at o pe ration Ju ne 195 4.

P. W IL E S , P . 5 . A N D R E W S A N D M . B . D E V A S 97

GV O L . 38 B, NO . 1, F E B R U A R Y 1956


4/19

98 T H O M A S F A IR B A N K B IR T H D A Y V O L U M Eso slow tha t the re a re no sym p tom s th rou gho u t life . In a few the chang es , a lm o st from th esta rt, a re m o re w ide ly sp read , and in som e of th ese p ro g res s is rap id . O ccasio na lly it is ve ryrap id ; the re is a ty pe in w hich the en tire su rface o f th e pa te lla d is in teg ra te s and , w hen th eknee is o pened , the syn ov ia l flu id is c lou ded by fragm en ts o f a r ticu lar ca rtilage . T h ere isa t p re sen t no su re w ay of tellin g b y c lin ica l exam ina tio n , o r even by insp ectin g the a rticu la rcar tilag e , w h eth er p ro g res s w ill b e slo w or qu ick , no r is th ere a con stan t re la tio n to anyfea tu re o f th e h isto ry , such as in ju ry . T he d ete rm in in g fac to r is m ore lik e ly to be fo un d inthe chem ica l b ehav iou r o f th e g roun d substance o f the ca r tilag e .

S om eth ing is k now n abou t the ave rage , o r s tatis tic a l, b eh av iou r o f ch ond ro m a lac ia a f tera clin ica l d iagn osis h as been m ade . K a rlso n (19 40) re -exam in ed sev en ty -one m en w h o h adbeen d iagno sed in A lem ans c lin ic b etw een o ne an d tw en ty yea rs p rev io usly w hen th ey w erea rm y co nsc rip ts , and w hose sym p tom s d id no t then w arran t op era tive trea tm en t. T en hadno sub jec tive com p lain ts , fo r ty -fiv e had a little tro ub le su ch as stiffne ss and fa tigue a fterseve re ex ertion , and six teen had h ad enou gh trou b le to m ake them change th eir w o rk or tocause f requ en t absen ce from w ork . T h ir ty -five w ere rad iog rap hed and seven show ed slig h tosteoa rth r itic changes bu t no ne h ad adv an ced a rth ritis .

W e a re fo rtu na te eno ugh to have seen and reco rded the p re sence o f f issu r ing in n ine teenknees op e ra ted upo n fo r o the r cond itions, the a rticu la r ca r tilag e be ing lef t in tac t. S even teenof the se o pe ra tion s w ere b etw een o ne and five yea rs ag o . In e leven knees on ly a sm a ll a reao f ca r tilag e w as affec ted ; fo u r now hav e no sy m pto m s, fiv e have a little ach ing or sw e llin ga fte r exe rc ise and tw o cann o t b e traced . T he fissu r ing w as o f m od e ra te sev erity in fo u r:on e no w has a n o r m a l kn ee, tw o h av e tro ub le som e sy m pto m s and o ne can no t be traced .T w o pa tien ts , b o th ope ra ted up on th ree y ea rs ago , then had seve re and ex tensiv e ch angesin the car tilage , and now bo th have c lin ica l and rad io log ica l s igns o f osteoa rth ritis . T heseob se rva tio ns sug gest th a t th e m o re w idesp read the chang es the m ore like ly they are top rog ress .

C ho ndrom alac ic chang es a re qu ite o f ten seen o n the fem ur a t sites co rre spo nd in g tothose on th e opp osin g su rface o f the p ate lla , b u t th is is by n o m eans inv a riab le . T he re m aybe ad vanced changes in th e p ate lla w itho u t any v isib le a lte ra tion in the fem ur, o r tho se inthe fem ur m ay b e m ore ad vanced th an the pa tella , an d occas iona lly the fem u r a lon e is a ffec ted .It seem s tha t a rou gh pa te llar su rface rub b ing o n the fem ur is no t the on ly cause o f the latte rsdegen era tin g . I t m ay b e tha t, a s in the pa te lla , a p red ispos in g fac to r m ust b e po stu la ted .C h ond ro m a lac ia o f the p ate lla som etim es p rog re sse s to o steoa rth ritis . T he course canno tbe fo llo w ed in a sing le pa tien t bu t a poss ib le sequ ence o f even ts can be show n in a ser ie s(F igs. 1 to 6 ). T he c lin ica l ev idence su gg ests tha t chon drom a lacia is le ss lik e ly to p ro g res sw hen , at the tim e o f d iagno sis , it inv o lves on ly a sm a ll a rea o f the sup erfic ia l and in te rm ed iatelaye rs o f the a rticu la r ca r tilag e, b u t the g rea te r the ex ten t and seve rity o f th e changes, th eg reate r the r isk o f osteoa rth r itis .

P A T H O L O G YN ak ed -eye app ea ran ces-C ho ndrom alac ia o f th e pa te lla beg ins a s a n odu lar sw ellin g o f pa rt o fthe ar ticu la r ca rtilage . I t is s itua ted m ore o ften on the m ed ia l than the late ral face t, com m on lyjust b elo w th e cen tre. T he n odu la r area is lu stre le ss and grey or y ello w in co lou r , and it isd is tin ct from th e g lis ten in g , b lue , n o rm al ca rtilage su rrou nd ing it. F issu re s deve lop in thenod u la r zone and rad ia te fro m it, sp litting the ca rtilage in to irregu lar f lak es (F ig . 2 ). T hefree edg es o f the flakes p ro ject abov e the su rface o f the su rroun d ing articu la r ca rtilage . T hefissu re s a re usua lly d irec ted ob lique ly in to th e d ep ths o f the car tilage so th at th e f lak es, w h envie w e d fro m th e su rface , do no t stand up rig h t b u t lie like the tiles o f a ro o f , pa rtly ov erlapp in geach o the r (F ig . 14 ) . T h ey a re firm ly a ttached to the u nde rly ing b one .

H irsch (1 944 ) h as dem o nstrated b y elabo ra te m e thod s th at, a t th e stage o f no du la r sw e lling ,the e la sticity o f ca rtilage in the a rea s o f chon drom a lac ia is le ss th an tha t o f the su rrou nd in g ,un dam aged ca rtilage . S om e e la stic ity rem a ins even w h en the car tilage is f issu red , as can

T H E JO U R N A L O F B O N E A N D JO IN T S U R G E R Y


5/19

I.

i 3.s .1 * .

1

S

II

F I G . 7 F IG . 8 F I G . 9Figure 7-N orm al a rticu la r ca rtilage of pa te lla s ta ined H . and E ., x 25 . F igu re 8-L oss of n orm al sta in ingin superfic ial an d m id-zo nes, a lso fissu re ex tend in g in to m id-zone . H . an d E ., x 20 . F igu re 9 -Irregu la r

stain ing o f superfic ia l and m id-zon e and cys ts in the la tter . H . a nd E ., x 5 0.

A

1

F I G . 10

(.

F I G . 12

V O L . 38 B , NO 1, F E B R U A R Y 1956

I$9 aII I $

II

I,, / {149}4

P . W IL E S, P . S . A N D R E W S A N D M . B . D E V A S 99

{149} a

, { 149} 0 {149} 4

pF I G . 11

Figure lO -H yperp las ia o f car tilage ce lls su rro unded by areas o f no rm al s ta in in g m atrix . T h e line of ca lcifiedcartilag e is b ro adened . H . an d E ., x 30 . F ig ure 11-Lo ose bod y from knee jo in t o f a case o f ch ondro m alac iash ow ing cell nests and areas of no rm al sta in ing m atrix . H . and E ., /K 25 . F igu re 12-L a te s tag e ofch ond rom alacia sh ow ing d ege nerate car tila ge w ith ossification and oed em ato us con nec tiv e tissu e in the

m arrow sp ac es. H . and E ., x 30 .


6/19

10 0 T H O M A S F A IR B A N K B IR T H D A Y V O L U M Eread ily be sh ow n by inse rtin g a fine p ro be in to a f issu re an d lif ting the ad jo in ing flake to anuprigh t po sition ; it snaps back in to its o rig ina l p osition w hen th e p robe is w ith d raw n .

T he dam aged ca rtilag e , a t firs t ra ised abov e th e leve l o f th e su rro und ing a rticu la r su rface ,g rad ua lly beco m es th in ne r and the f lak es acqu ire a sh aggy ap pea rance (F ig . 3 ). T h ey a rethen les s e la stic and so fter , so m uch so tha t sm a ll p iece s o f fray ed ca rtilag e can b e de tach edby rubb ing w ith a fin ge r. O n op en ing kn ees w ith car tilage ch an ges such as the se , it is com m onto find ca rtilag inou s loose b od ie s w ith rou nded edges ly ing free in the jo in t.

W hen the con d ition is p rog re ssive th e size o f the d am ag ed a rea inc rea se s an d invo lvesm os t o f the m ed ia l facet, the rid ge and th e la tera l facet, u su ally in th is o rd er . T he ca rtilagebecom es so th in tha t the un de rly ing bo ne is ex posed , g iv ing an appea rance ra the r like an u lcer su rrou nded by a rim o f frayed ca rtilage (F ig . 3 ). T h e a rea o f ex posed b one in creasesand ev en tua lly beco m es eburna ted and often sco red in a ve rtic a l d irec tio n (F igs. 4 to 6 ).

O steoph y te s deve lop at the m arg in o f th e p ate lla r ca r tilag e w he re it jo in s th e syn ov ia lm em b rane an d capsu lar tissu es . T hey app ea r so ft, a s rou nded m asses o f b one cov e red by ath in , g rey -w h ite laye r o f ca r tilag e. T hey d o n o t o ccu r in the nod u la r phase , bu t la ter w hen th efissu r ing is deep o r ex tensiv e and the ca rtilage is th in . T h is is th e stage o f o steo a rth r itis ; itis reached b y on ly a few p eo p le und erthe age of fo rty -f ive b u t the rea fte r it becom es in creas ing lycom m on . T he re is a clo se co rre la tion b etw een th e site s o f th e ca rtilage dam age and o steoph y tefo rm a tion . T h e m ed ia l face t is the m o st freq uen t site o f ca rtilage d am ag e, and the m ed ia lborder is th e usua l s ite o f o steophy te fo rm ation . W h en the la te ra l face t is inv o lved , os teo phy testend to fo rm alo ng the la tera l bo rde r . T he m o re seve re th e le sio n th e g rea ter is the p robab ilitytha t osteoph y te s w ill deve lop ; o f ten pa te llae rem ov ed su rg ica lly fo r sev e re ch ond ro m a lac ia ,n in e had m arg ina l osteo phy tes.

T h e p ate lla r face ts on the fem u r m ay sh ow changes in the a rticu la r ca r tilag e w h ich a reso m e tim es re fe rred to as m irro r le sions . T he m ed ial pa r t is m o re o ften affec ted than thelate ral, th e n ak ed -eye app ea ran ces re sem blin g those in th e pa tella . O ccasio na lly th e pa tella rface ts o f the fem ur a re invo lved a ltho ugh the p ate lla is no rm al.

T h e syno v ia l m em b rane show s som e h ype raem ia an d pro lifera tion in a lm os t eve ry caseo f ch ond ro m a lac ia . In a few , usua lly n ea r an a rea o f fissu rin g , a syn ov ia l p an nus sp readsov er the ou te r rim of the a r ticu lar ca rtilage (F igs . 1 and 2). T h is p an nus co nsists o f rela tive lyvascu la r co nnec tive tissue cov ered by flattened syn ov ia l ce lls , and it is so firm ly adh e ren tto th e ca rtilage as to b e in sepa rab le .H isto log y-N o rm a l a rticu la r car tilag e is h ya line ca rtilage p osse ss in g th ree po orly d efinedlaye rs (F ig . 7 ) . T he deep es t lie s on the lin e o f calc ified car tilage ov er th e chon dro -o sseou sp la te , an d it con tain s la rge ce lls a rranged in v ertic al co lum ns. T h e ce lls in th e transition allay er run o b liqu ely , an d in th e supe rfic ia l lay er they a re pa ralle l to the su rface . T h e size o f th ece lls d ec rea se s from the deepe r zones tow ard s the su rface . M ito tic figu re s a re n o t seen inan y laye r o f n o rm a l car tilage . T h e m a tr ix in the deep zone is p len tifu l an d sta in s a deepb lue w ith h aem ato xy lin an d eo sin , bu t nea re r the su rface it s tain s les s d eep ly and app ea rsm etach rom a tic (F ig . 7 ) . N o fib re s a re v isib le in no rm al car tilag e exam ined b y rou tin eh isto log ica l m ethod s.N odu la r sw e lling , w h ich is the ear lies t s ign o f cho ndrom alac ia, h as a typ ica l m ic ro sco p ica lp ic tu re . T h ere is no v isib le a ltera tion in th e car tilage ce lls , bu t the m a tr ix is chan ged an dw hen it is s ta ined w ith h aem a tox y lin and eosin th e supe rfic ia l and transition al zo nes app ea rp in ke r (F ig . 8 ). W e have fo und , using spec ial techn iques su ch as th e pe rio d ic ac id Sch iffreac tion (P .A .S .), tha t the re is a dec rea se o f P .A .S . po sitive m a trix in sw o llen a rea s; th isind ica te s a dec rea se in the chon dro itin su lp huric acid con ten t. H irsch (1 944 ) and M atthew s(1 953 ), u sing b io ch em ical m e thod s, have m ade a sim ila r dedu ctio n . I t seem s, the refo re,tha t the ea rlie st change in ch ond rom a lac ia is an alte ratio n in the chem ica l struc tu re o f th ematr ix .Fi s sure s -The ea rlie st fissu re s r u n tan gen tia lly to the su rface, bu t the deepe r the f issu res th e

T H E J O U R N A L O F B O N E A N D JO IN T S U R G E R Y


7/19

P . W IL E S , P . S . A N D R E W S A N D M . B . D E V A S 10 1m ore ve rtic a l is the ir cou rse (F ig . 8 ). T he gro und sub stance , w h en ex am ined w ith da rkg ro und illum in atio n , show s a fine , w eb-like sys tem o f th in f ib r ils w h ich en c irc le ca rtilagece lls o r g rou ps o f ce lls . T h e fib r ils app ear to be in tac t ev en w hen th ere is m arked fissu rin g .

B enn ingh off (1 925 ) dem o nstrated by m ace ra tion o f no rm a l a r ticu lar car tilage an orde rlysystem o f f ib res arran ged in arcad es . A ltho ugh the course o f the fissu re s co rre spo nds w iththa t o f B en n in gho ffs fib re s , w e have no t been ab le to dem on strate any such fib res inn orm a l o r d eg en era te car tilage o f the pa tella eith er b y s ilve r im preg na tion or by exam in a tio nw ith p o la ris ed lig h t.

Thir ty -one spec im ens o f pa te lla r ca rtilage rem ov ed a t o pe ra tion on accoun t o f cho ndro -m a lac ia have been exam ined an d the dep ths o f the f issu re s co m pared w ith the los s o fm e tach rom asia. T he re su lts a re show n in T ab le III .

T A B L E IIIC O R R E L A T IO N B E T W EE N L O S S O F M E T A C H R O M A S IA A N D F IS S U R E F O R M A T IO N

F issu r e for m ationMe t a c h r o m a s i a N one S u pe rf ic ial H a lf th ick ness F u ll th ick nessS lig ht loss 1 6 0 0M o dera te lo s s 0 5 12 3C om p lete l o ss 0 0 1 3

O f fou r specim en s w ith com ple te lo s s o f m e tach ro m asia , deep fissu re s w ere p re sen t inth ree . O f the tw en ty sp ec im ens sh ow ing m o de ra te lo ss o f sta in ing of the m a trix , th ree h adfissu re s reach in g th rou gh the fu ll th ick ness. T he re is , the refo re , co rrela tion be tw een thealte red s tain ing reac tio n of th e car tilage and th e dep th o f the fissu re s.C ysts o f cartila ge -C ysts a re o ften p resen t in d eg en e ra te ca r tilag e w hen th ere is fis su r ing .T h ey app ea r as irregu la r sp aces, u su ally situ ated at the b ase o f f issu re s, bu t som e tim esnea re r the su rface (F ig . 9 ). A ltho ugh a m a jo rity are em pty , a few con ta in a ho m o geneousge la tino us sub stance w hich stain s som e tim es w ith h aem a tox y lin an d som etim es w ith eosin ,bu t neve r w ith b o th . I t d oes n o t, w he the r it is ba so ph ilic o r eosin oph ilic , g iv e a co nstan tP .A .S . reac tion . C ysts w ere p re sen t in tw en ty ou t o f th ir ty -one su rg ica l spec im ens; m e tach rom icsta in in g of the ca r tilag e arou nd them w as red uced , s ligh tly in six , m ode rate ly in th irte enand com p lete ly in on e.H yp erp la sia o f cartila ge -In w ell es tab lished ch ond ro m a lac ia the re are foca l a rea s in w hichthe ca r tilag e ce lls sho w h ype rp la sia b o th by fo rm ing cell n ests and by a re tu rn o f th e sta in in gprop ertie s o f the g rou nd substance in and arou nd the n ests . T h e groun d su bstance ap pea rsto be stream ing a ro und the ce ll ne sts (F ig . 10 ). T he process can b e in te rp reted as an attem p ta t regene ra tion , bu t it rem a ins c ircum sc ribed an d th e con tin u ity o f the ca r tilag e is n o t resto red .T he ca rtilag in ou s lo ose bod ies fou nd in ch ond ro m a lac ia behave in a sim ila r w ay (F ig . 11 ) .

T w o spec im ens hav e b een ex am ined in w h ich th e a rticu la r ca rtilage had firs t been rem o vedat o pe ra tion an d then , ab ou t a y ear la ter , the pa te lla w as ex cis ed . T h e a rticu la r su rface s o fthe pa te lla sh ow ed o n ly a few area s o f regene ratio n , the n ew ca rtilage be ing fib rou s rath e rthan hy alin e in stru ctu re . A sim ila r app earance is o ften seen a fte r m ou ld arth rop lasty o fthe h ip , a s f irs t reco rded by Sm ith -P ete rsen (194 8) .Bone a nd basa l car tila ge -T h e reac tion o f bon e u nde rly ing a rea s o f cho ndrom alac ia isp ro lifera tive . T h e ch an ges beg in w hen fissu re s f irs t app ea r in the ca rtilage and then the lineo f ca lc if ied ca r tilag e inc rea se s in th ickness (F ig . 10 ) . A s the fissu rin g ex tend s in to the car tilagethe in c rea se con tinues u n til the th ick ness o f th e line is d oub led or treb led . N ew bon e is fo rm edin the b asa l zone an d sm a ll b lo od vesse ls fro m the m arro w spaces pene trate the lay er o fV O L . 3 8 B , NO . I, F E B R U A R Y 1956


8/19

T H E J O U R N A L O F B O N E A N D JO IN T S U R G E R Y

10 2 T H O M A S F A IR B A N K B IR T H D A Y V O L U M Eca lc ified ca rtilage . T he re is n o ev id en ce o f ischaem ic nec ro sis in th e b one e ithe r be fo re o raf te r the ca r tilag e is e ro ded .

A com parab le reac tion takes p lace a t th e edg e of th e p ate lla . T he su rface ca r tilag ep r olife rate s, p r od u c in g car tilage of a fib r ou s typ e , oss ificatio n occ u rs in th e deepe r laye rs ,an d m arrow sp aces fo rm in the new bo ne . T h us are fo rm ed expan d ing no du le s o f f ib roca rtilagew hich o ssify in th e deepe r pa rts to becom e o steo ph y te s. T h is p rocess occu rs nea r a rea s o fad v an ced ca rtilage d e ge n er ation an d it a lso can b e in te rp re ted as an e ffo r t a t regene ratio n .O ccasio na lly p ro life ratio n occu rs at the cen tre o f a face t (F igs. 1 5 and 16) .

F I G . 13S ection o f a k nee flexed 75 degrees sh ow in g the ex ten to f the co ngru ity o f the articu la tio ns be tw een the m edia lan d la te ra l pa te lla r face ts an d the fem ur.

Bone cysts-The bon e un de rly ing areas in w hich the ca r tilag e h as been destroy ed becom essc lerosed , and sm a ll cy stic spaces f illed w ith oedem a tous con nectiv e tissu e ap pea r benea ththe su rface (F igs. 12 an d 16 ). T hese cysts h av e stom a ta com m unica ting w ith th e jo in t, bu tw e h av e n ot see n an y d e tritu s from the jo in t in side them .

E T I O L O G YT he ea rlie st d em on strab le chan ge in chon drom a lacia o f the pa te lla is an a lte ra tion in

the reac tion o f the car tilag e m a tr ix to stain ing . T h is is due n o t to oedem a , a s m any au th o rshave m ain tain ed , b u t to a dec rea se in the chon dro itin -su lp huric ac id con ten t. It beg ins inthe low er pa rt o f th e m ed ial face t o f th e p ate lla , w h ich is sa id b y O w re (1 936 ) to b e the th ickesta rticu la r ca rtilage o f th e b ody . T h e rea so n fo r th is lo calisa tion has been investig ated byW ibe rg (1 941 ). H e cu t slic e s o f no rm al k nee jo in ts frozen a t d ifferen t an g le s o f f lex ion andsho w ed tha t, in th e flex ed k nee , con gru ity be tw een the m ed ia l ar ticu la r su rface s o f the p a tellaand the fem ur w as a lw ays le ss th an be tw een th e la te ra l a rticu la r su rface s.

W e have confirm ed W ibe rg s ob se rva tion usin g a rap id -freeze tech n iqu e (F ig . 1 3 ) . T hela tera l facet o f th e pa te lla i s co n cav e in tw o p lan es an d m akes co n tact w ith th e fem ur th roug h


9/19

F igu re 1 4-F issu r ing of th e inne r and low er quad ran t o f the a rticu la r ca rtilage . F igu r e 15 -A n osteophy teis deve lop in g in the m id d le o f th e lo w er an d inne r qu ad ran t b en ea th fissu red and p artia lly e ro ded ca rtilage .

t

P . W IL E S , P . S . A N D R E W S A N D M . B . D E V A S 10 3

V O L . 38 B, NO . 1, F E B R U A R Y 1956

F I G . 16 F I G . 17Figu re 16-T h ere is a cy st in the bo ne at the ou te r s id e , and an o steophy te is fo rm ing near the m edian ridge .F igure 17-T h e en tire su rface of he cartilag e is ro ugh an d an os teo phy te is fo rm ing a t the ou te r m arg in .

m u ch of th e ran ge o f m ov em en t. T h e m ed ial face t is , ho w eve r , s ligh tly con vex and it to uchesth e co n v ex su rfa ce of th e f e mu r on ly a t a s in g le p o in t, excep t w h en the kn ee is f lexed le ss than6 0 degree s. T h e lo w er pa rt o f th e m ed ial face t m akes even le ss co n tact th an the u ppe r pa rt,and it ha s been su ggested by seve ra l w riters tha t cho nd rom alac ia is cau sed by m echan icalstress app lied to th is su rface . T he su ppo rting ev idence is no t strong .

H a rr ison , S cha jow icz and T rue ta (195 3), w hen stud y in g osteoa rth ritis o f the h ip , fou ndth at the re w as m ore d am age to the ar ticu la r car tilage a t th e n on-w eig h t-bear ing th an at th ew e igh t-bea rin g areas o f th e fem o ra l head . T hey sugg es ted tha t no rm al m o vem en t w ith itsa lter n atin g p r essu re and re st ex erted a pu m pin g ac tion w h ich he lped to m a in ta in the nu tr itiono f ar ticu la r ca r tilag e. T he pa tella is n o t a w e igh t-bea rin g su rface , and slab rad iog raph s don o t sh ow a trabecu lar p atte rn de linea tin g stressed an d non -stre ssed a rea s o f bon e (F igs. 1 4to 17 ). Ne ve r th e le ss th e lo calisa tion o f th e les ions in th e pa te lla supp orts the the sis tha tth er e is a n asso ciatio n b e tw ee n p re ssu r e, or its ab se n ce , and the ev o lu tio n of chon drom a lac ia.W he the r th is is so o r no t, it is ou r v iew tha t traum a is o f im portance m ore o ften as anaggrava ting th an as a p rim ary facto r, and tha t it a cts by d isru p ting a lready d e ge n e r ateca rtilage . T he fin al stage o f o steo a rth r itis is rega rded as th e re su lt o f ch anges in ca rtilage ,bo ne and syno v ia l m em bran e tak in g p lace as a reac tion to d eg en e ra tion o f the ca rtilag e an dto the libe ratio n o f free p artic les o f degen era te ca rtilage w ith in the jo in t.

C L IN IC A L F E A T U R E SS ym p tom s-T he pa tien t is co m m o nly a y oun g ad u lt o r in ea rly m idd le age , bu t sym ptom sm ay occ u r d u rin g a d ole sc en c e an d o ccasion ally in ch ildh ood . T he onset is o f ten in sid iou s,bu t it m ay be p rec ip ita ted by a m ino r in ju ry such as a b lo w or a tw ist w h ich is reg arded bythe pa tien t a s the cau se . O ccasio na lly the re is a h isto ry o f a m o re v io len t in ju ry sev era l m on th s


10/19

10 4 T H O M A S F A IR B A N K B IR T H D A Y V O L U M E


b e for e the sy m pto m s beg in . S om e d isab ility m ay have been pre sen t fo r m on th s o r y ea rs ,an d ad v ice is soug h t on ly a fte r a sudd en ex ace rb a tion .

W hen the o nse t is in sid io us the re is a t firs t d is co m fort ra the r th an pa in ; it is no ticeda fter exe rcis e and is no t w e ll loca lised . T h ere m ay a lso b e d iscom fo rt a f ter s ittin g fo r som etim e , w hen firs t m oving afte rw ards , o r w h en go ing dow n sta irs. L a te r th e fee lin g of d iscom fo rtis rep laced by pa in , and there is o ften som e sw elling from effu sion . T h e sym p to m s are ,h ow ev er , in te rm itten t and , sin ce the knee retu rn s to n orm a l a fte r a co up le o f days, gam es

such as fo o tba ll h ave no t been g iv en up . A t a m oread va n ce d stag e, w hich is reach ed b y com p ara tive lyfew , the p ain an d sw e lling becom e con stan t, w ithexa cer b a tio n after stres s. T here is con side rab led isab ility , and m o st gam es and the heav ie r ty peso f w ork a re im p ossib le .

A h isto ry o f c atc h in g of th e knee d uringflex ion o r ex ten sion , bu t s eld om bo th , is com m on .T h e p a tien t m ay say th at th e kn ee le ts h im dow n .Th e catch , w h ich is p ro duced by a p artlyde tach ed flak e o f ca rtilage (F ig s. 1 , 3 an d 1 8) , isfe lt du ring flex ion w h en the low er en d of the flak eis loose and d uring ex tensio n w hen the up pe r endis fr ee. I t m ay b e m o re no ticeab le w h en a littlep re ssu r e is app lied to th e pa te lla du rin g m o vem en t.

. F I G . 18 { 149} T rue lock ing occu rs w hen th e re is a loo se bo dy inC ase 16 -T he a rtlc u la r car tila ge after re m o val . . . . .sho w ing a la rge flap . th e J oln t, as is q u lte co m m on in ch on d ro m alac ia .T h e h isto ry can b e sum m arised as on e of

in term itten t d iscom fo rt o r p ain w h ich is w orse a f ter s itting o r a f ter ex erc ise , pe rh ap saccom p an ied b y a m od era te e ffus ion and so m e tim es by a ca tch during m ov em en t. T h erem ay be a spo n taneous rem issio n , o r m ild sym p tom s m ay co n tinu e inde fin ite ly w ith ou t ge ttingw or se . S om e tim es th ere is an ex ace rb atio n assoc ia ted w ith in ju ry ; so m e tim es th ere is g radua ld ete r io ratio n un til fina lly th e sym ptom s m erg e w ith th ose o f o steo arth r itis .Physical s igns- A p ositive d iagno sis o f cho ndrom alac ia can be m ade by th e ph ysica l s igns,b u t n eith er the h isto ry nor th e s igns g ive a re liab le in d icatio n o f the seve rity o f the pa tho log ica lchan ges. T he a rea o f ca rtilage inv o lved can u sua lly b e de term in ed , bu t no t the stage tow h i ch d e ge n e r at ion has p rog re ssed . T he re m ay be con side rab le d is ab ility and m arkedt e n d e r n e ss b en ea th the pa tella w hen the re is n o m ore th an a little fissu rin g of the ca rtilage ,o r the ca rtilage m ay be in a state o f adv an ced d isin teg ra tio n w hen b o th sym p tom s and sign sa re re lativ ely s ligh t.

A var iety of phy sica l s ign s have been d escr ibed bu t seve ral a re o f little d iag nostic va lue :pa tello -fem oral crep itu s on ac tive m ovem en t o f th e knee , pa in caused b y rub b ing th epe rip ate lla r tissue s aga inst the ed ge of the bo ne , e ffusio n , and en la rgem en t o f the in frapa tella rfa t pads m ay be p r e se n t bu t are op en to o th er in te rp re ta tion s. P a te llo -fem o ra l c rep itu s ispa rticu la r ly m islead ing . T he im portan t phy sical s ig ns a re :I) Pain on gr atin g th e pa te lla ag ain st the fem ur. W ith th e kn ee ex tend ed , th e m u scle sare re laxed and each quadran t in tu rn is gen tly ro lled on the fem ur. T h e re la tion o f th epa tella to th e a r ticu lar su rface o f th e fem ur v aries , an d it ma y be n ecessa ry to p ush th epa tella do w n w ards to en su re tha t a ll its a rticu la r su rface com es in to con tac t w ith thef em u r .

Pain m a y also be caused by p re ssu re on the pa te lla w h ile the jo in t is m oved ac tive ly o rpassive ly ; a s a ru le it is fe lt on ly at cer ta in po in ts on th e arc o f m ov em en t.2) Tenderness o n p re ssu re ove r the a rticu la r su rface o f the pa tella . T h is is acce ssib le topa lpa tion w hen the b one is d isp laced firs t to one side an d th en th e o the r (F ig . 19 ). T he am o un t


11/19

.)

P . W IL E S , P . S . A N D R E W S A N D M . B . D E V A S 10 5

V O L . 3 8 B , NO . 1, F E B R U A R Y 1956

it c an be d isp laced va rie s w ith the in d iv id ua l bu t o f ten the w h o le und er-su rface ex cep t them ed ian ridg e can be fe lt, and even tha t is ex posed w hen the capsu le is ve ry lax .3) A ca tch o n flex in g o r ex ten d ing th e k nee can often b e fe lt w hen the re is a pa rtly de tachedflake o f ca rtilage (F igs. 1 , 3 an d 18) . I t ma y b e easie r to de tect w hen the pa te lla is g en tlyp re ssed aga in st the fem u r, and it a lw ay s occu rs a t the sam e po in t on th e a rc o f m o vem en t.

T he p re sence o f pa in o n gra ting the pa tella , tog eth e r w ith ten de rn ess b en eath the pa tella ,a re d iagno stic o f chon drom a lac ia p ro v ided o the r d isea se s such as rheum a to id a r th r itis h av e

F I G . 19E xam in ing for tenderness beneath the pa te lla .

b een exc lu ded . B o th s igns m ust be p re sen t and a t ex ac tly the sam e pa rt o f the pa tella . C a rem u s t a lso b e taken to en su re th a t th e n atu ra l d iscom fort o f the exam ina tion h as no t beenm isin te rp re ted by the p atien t. A t o pe ra tion the area o f ca rtilage in vo lv ed is o f ten foun d tob e grea te r than the phy sical s ign s su ggested , bu t o n ly o ccasion a lly le ss .

P a in and tend erness are usua lly seve re w hen a vascu la r pann us cove rs pa rt o f the a rticu la rca r tilag e (F igs. 1 a nd 2) . B u t w h en the re is no pann us, an exp lana tion of the se sig ns is no t easyto f ind because a rticu la r ca rtilage co n ta ins n o senso ry ne rve end in gs, no r have w e b een ab leto d em on str ate them in abn orm a l car tilage . A n ob v iou s sugg es tion , so far as ten d e rn e ssb en ea th the pa te lla is con cerned , is tha t the syno v ia l m em bran e in te rp osed b etw een the fing e rand th e ca rtilage is in flam ed . H o w ev er , the sam e area o f syno v ia l m em brane is s eld om tend e rw hen pressed aga ins t th e fem ur, an d at su bsequen t o pe ra tion it u sua lly appea rs to b e n orm a l.N or is th e tend erness in th e pe ripa tella r syno v ia l fo ld (a ltho ugh th is , w hen in flam ed , cause stend erness a t the m arg in o f the pa tella ) b e c au se it cann o t be inv ag ina ted fa r eno ugh .R ad iog raph ic exam in atio n -R ad iog raph s a re o f a ss is tan ce on ly in so fa r as they ex clu de o the rd isease. In ear ly an d m od era tely ad vanced ch on dro m a lacia th e bon e is no t in vo lv ed an d theth ickness o f the ca r tilag e is n o t g rea tly red uced , so b o th the bo ne and the jo in t spaceap pea r n o rm al. W e have m ade m an y attem p ts to dem o nstrate the ar ticu la r car tilagerad io lo g ica lly using eve ry p ro jec tion w e cou ld th ink of , b o th w ith and w itho u t the a id o f a iran d o the r con tra st m ed ia , bu t on ly on ra re occasions h ave they been successfu l.

D IFF E R E N T IA L D IA G N O SISA p o sitive d ia gn osis o f ch o n d ro m alac ia is , in ou r exp e rie n ce , n ear ly a lw ay s co rr ec t, bu t

even w hen one is w e ll aw are o f th e con d ition and is co nstan tly o n the w atch fo r it, it issu rp r is ing h ow often it is tho ugh t to b e som e th in g e lse . T he com m on m istake is to ca ll


12/19

10 6 T H O M A S F A IR B A N K B IR T H D A Y V O L U M Echo ndrom alac ia a tear o f th e m ed ia l sem ilu na r car tilage , and nex t in freq uency is th e failu reto reco gn ise it a s a cause o f lo ose bo d ie s. T h e assoc iatio n o f ch ond rom a lac ia w ith recu rren td is lo catio n of the p ate lla is too w e ll kn ow n fo r the fo rm er to be ov erlook ed (M acnab 1 952 );bu t it is no t so w ell k now n tha t the pa tella is o f ten a ffec ted w hen the re is o steochon dritisd issecans o f the fem ur. S ystem ic d is ea se s such as rheum ato id a r th ritis a re un lik ley to causecon fu sion prov id ed rea son ab le care is tak en .In ju r ies o fthe m ed ia lsem ilu nar ca rtilag e-M ost ex pe rienced su rgeon s w ill ad m it an appreciab lee rro r in the d iagn osis o f lesio ns o f the sem ilun ar ca rtilages. W e have m ad e th is m istake n inetim es du rin g the six yea rs 195 0 to 1 955 , an e rro r o f f ive pe r cen t, an d o n each o ccasion the rehas been chon drom a lacia su ff icien tly ad vanced to acco un t fo r th e sym p tom s. T he d ifficu ltya r ises ch ie fly w hen the re is a h isto ry o f a tw is t, p e rhap s a t foo tba ll, w h ich p rec ip ita ted theon se t o f sym ptom s, and w h en th ere is com pla in t tha t the knee le ts m e do w n , e spec iallyif the re is a lso tende rness cau sed by d etached fragm en ts o f ca r tilag e tha t have fa llen to thelo w est pa r t o f the jo in t. In the se c ircum stan ces, if the pa te llar pa in an d ten de rn ess a re bu tslig h t, it is tem pting to in cr im in ate th e sem ilun ar ca rtilage .Loose bod ie s-D e tached flakes o f a r ticu lar ca r tilag e so o ften g row in size and ca lc ify in thecen tre tha t ch on dro m a lacia sh ou ld b e suspected w h en the re a re lo ose bo d ie s in the k nee ,w he the r o r no t th ere is rad io lo g ica l ev idence o f os teo ch ond ritis d issecans o f th e fem u r.

T R E A T M E N TT h e re su lts o f op era tion can be d iscov ered by th e o rd ina ry m e tho ds o f fo llo w -up , bu t

th e d iff icu lty in a sse ssin g con serva tive m easu re s is tha t th e p rec ise co nd itio n o f th e a rticu la rca r tilag e is usua lly unk now n . N e ithe r the sym ptom s nor th e signs a re a re liab le g u ide to theex ten t o f degene ratio n . M oreo ve r, in the absence o f trea tm en t, d ete r io ratio n in so m e kneesis rap id , in som e it is s low , and o the rs ap pear to recov er . U n til th ere is a c lin ical m eth odof gaug ing accu ra tely th e co nd itio n o f the ca rtilage and of fo llow ing its cou rse in ind iv idua lp atien ts the p ro gno sis m u st rem ain unce rta in and treatm en t can o n ly be s ecun dum ar tem .

T he p ro b lem of trea tm en t m ay b e pre sen ted to the su rgeon in seve ra l w ay s : 1 ) a fte r ac lin ical d iag nos is o f chon drom a lac ia , o r o f ch on dro m a lacia a sso cia ted w ith an o the r d iso rde r ;2 ) on d isco ve ry o f chon drom a lac ia at an ope ratio n pe rfo rm ed fo r an o the r con d ition th at ha sb een m isd iag nosed , th e sym ptom s rea lly b ein g d ue to cho nd rom alac ia , o r fo r an o the r co nd itio nth a t p rov ed to be pre sen t, th e cho ndrom alac ia hav in g cau sed no sym ptom s, o r on ly triv ia l o nes.

A c lin ical d iag nosis m ay b e m ade at an y stage in the co urse o f the d isea se becau se som epa tien ts p re sen t th em se lves w ith tr iv ia l sym ptom s, w he reas th e m ore robu st w a it u n til theya re in cap ac ita ted . T he re is an in f in ite va r iatio n fro m triv ial th roug h m o de ra te to seve re .T rea tm en t is ha rd ly in dou b t a t th e ex trem es. W ith m ino r sym ptom s an d co rre spon d ing lysligh t phy sica l s igns it m ust b e conse rva tive . W h en th e sym ptom s a re incapac itatin g andlo ng con tinued , op era tion g iv es th e best chance o f re sto r ing fu nc tion . T h e in term ed ia teg rades shou ld f irs t be trea ted co nse rv ativ e ly and o pe ra tion con side red on ly if the re is con tin uedde te rio ra tion . T h ere is in su ff ic ien t in fo rm a tion as to w h ich kn ees w ill u ltim a te ly d ev e lopos teo arth r itis to ju stify ope ratio n fo r th is reaso n a lo ne . It is ou r p rac tic e to ad v ise ope ratio non ly w hen it is ind ica ted by th e seve rity o f the d isab ility . E xc ision of the pa tella u sua llyg iv es a goo d or a fa ir resu lt, bu t se ldo m a pe rfec t o ne , an d th ere m ust be a rea sonab le p ro spec ttha t th is op era tion w ill le ave the pa tien t w ith a be tter knee than h e a lready h as .

D iscove ry at o pe ra tion o ffe rs ra the r a d ifferen t p rob lem b ecause th e exp osu re has a lreadyb een m ade and the con d ition o f th e car tilage can be seen .

S m a ll areas o f sw o llen o r so ft ca rtilage are p ro bab ly best le ft un touched , bu t if th ere isf issu rin g th e a ffec ted ca rtilage m ay b e shaved off; it is u sua lly u nnecessa ry to rem ove thew h o le th ick ness. L esion s o f th is so rt w ill b e fo und qu ite o f ten if the un de r-su rface o f thepa te lla is in sp ec ted a t eve ry ope ratio n . A reas up to abo u t on e inch in d iam e ter can be sh av ed

TH E JO U R N A L O F B O N E AN D J O IN T S U R GE RY


13/19

P . W IL E S , P . 5 . A N D R E W S A N D M . B . D E V A S 10 7

V O L . 38 B , NO 1, F E B R U A R Y 1 9 5 6

a fte r s ligh tly en larg in g the inc ision fo r m en iscec to m y ; the p ate lla need n o t be eve rted and thetim e of recov ery is no t m ate ria lly pro long ed .

A dv an ced ch ond rom a lac ia tha t ha s c lear ly been cau sing sy m pto m s sh ou ld be d ea lt w ithin th e sam e w ay as if the ope ratio n w ere o ne o f cho ice . In th e absen ce o f p rev iou s p erm issio nit m ay , ho w ev er , be inad v isab le to exc ise the pa tella .Conser vat ive tre a tm en t-T h ere is no ev id en ce tha t co nse rva tive m easu res have any e ffect onthe cou rse o f the co m pla in t. M an y pa tien ts w ith m ild sy m pto m s im prov e w itho u t trea tm en t,and m an y im prov e w ith it. H ow eve r, the c lin ica l im pres sion is th at tre a tm en t is re sp onsib lefo r so m e am e lio ratio n . D uring th e las t th ree y ears w e h av e treated conse rva tive ly u pw ardso f on e hun dred pa tien ts . T h ose w ith triv ia l sy m pto m s have se ldo m a ttend ed fo r lo nge r than afew w eek s, bu t w hen the d is ab ility h as b een greate r , th ey have o ften thou gh t it w o rth w hile tocon tinue fo r m on th s. T he effect on the subsequen t course w ill n o t be k now n for som e years .

{ 149} - { 149}

F I G . 20C ase 28 afte r rem ov al o f nearly a ll th e a rticu la r ca rtilage of th e p ate lla.

T h e m e thod s o f trea tm en t ava ilab le a re res t, sh o rt-w av e d ia the rm y , and in tra -a r ticu larin jectio ns. D iath erm y is p resc r ibed in eve ry instance . R est, w hen th e sym p tom s a re triv ia l,m ay con sist o n ly in av o id in g gam es an d all ex erc ise th at is n o t e ssen tia l, bu t occupa tion sin v olv in g c om p le te and p ow erfu l ex tens io n o f the kn ee , su ch as b a lle t danc ing and w a lk in graces , sh ou ld be stop ped . W ith m ore sev ere sym p tom s im m obilis atio n is d esirab le an d ab iva lved p las ter-o f-P aris (o r po ly thene ) cy linde r is app lied w ith the k nee flexed 1 5 d e gr e e s .I t is tak en o ff at n ig h t, an d to facilita te d iath erm y . E xe rcis es w ithou t re sis tance m ay b e g iv ento red uce th e am o un t o f w as tin g o f the q uadriceps , b u t ex erc ise s ag ain st re sis tance arecontra- indicated. W e have n o e xp e rie n ce of in tra-articu lar in ject ion o f h ydroco rtison e fo rth is c om pla in t.O p e ra tio n -T w o p r oce d u r es h ave b ee n p r actised -r em o val of th e a ffec ted a rticu la r ca rtilageand exc ision o f th e pa te lla . P a tello p la sty has no t b een a ttem pted because ou r exp erience w ithth is ope ratio n p erfo rm ed fo r os teo arth r itis ha s no t b een su ffic ien tly en co urag ing .

T h e p ate lla is firs t in spec ted th ro ugh a m ed ia l p arapa te lla r in cis ion , and if ex tensiv ec h an ge s a re seen the in cis ion is p ro lo nged to a llow the bon e to b e eve rted . T h e com ple tein c is ion b egin s a t a p o in t in the m id -line one and a ha lf inches abo ve th e pa te lla , an d ex tendsd ow nw ards fo r an inch , sp litting the qu ad riceps. I t th en cu rves roun d th e inne r sid e o f theb one , d iv id ing the m uscu lo - ten d ino us ju nc tion an d approaches th e m id -line ag ain at the lev e lo f the tube ro sity o f the tib ia .


14/19

10 8 T H O M A S F A IR B A N K B IR T H D A Y V O L U M EE xtensiv e fissu r ing , flak in g an d e ro sion o f a con side rab le a rea o f the a rticu la r ca rtilageisannd ica tion to rem ov e it, bu t w he the r th is is b e st e ffected by shav in g off the a ffected

ca r tilag e o r by exc ising th e pa tella is no t ye t estab lished .R em ov al o fca rtila ge -T his has been our p ractic e w hen the area inv o lved has n o t been grea te rthan ab ou t one -th ird o f the w ho le . W ith m ore ex tens ive in vo lv em en t w e have rem ov ed th ea ffected car tilage , if neces sary , from the en tire pa te lla , w hen ch ond ro m a lac ia has been a chancefind in g an d p erm issio n to exc ise the p ate lla has n o t been o b ta ined . It h as a lso been don e o no th e r o ccasion s af te r p rev io us d iscuss ion w ith the pa tien t.

T A B L E IVM E T H O D O F T R E A T M E N T IN S Ix T E -n va K N E E S W IT H C H O N D R O M A L A C IA O F

TH E PA T E L L A S E E N A T O P E R A T IO N

M a l e s F em ale s T o talSeen a t op era tion , no t trea ted . . 14 5 1 9P art o r a ll a r ticu lar ca rtilage rem ov ed 20 11 31P ate lla e xc ise d . . . . . 7 8 1 5T ota l nu m ber o f knees . . . 41 24 65*

a T he num ber o f p atien ts co ncerned i s s ix ty -t wo .

N o du la r , so ft car tilage shou ld b e rem oved as w e ll a s fissu red . T h is is d one b y shav in gw ith a sca lp e l, the hea lthy ca rtilag e be ing b ev elled a t the m arg in to leave a sm oo th su rface.T h e b one is no t u sua lly expo sed bu t rem a ins co ve red w ith th e b asal lay er o f ca rtilage (F ig . 20 ) .O n a few occas ions a sm a ll area o f the fem u r has b een trea ted in the sam e w ay , bu t ex tens iveaffec tion o f the fem o ra l p a rt o f the jo in t is an ind ica tion fo r exc isio n of th e pa tella . P o st-ope rativ e recov ery is o ften ra the r slow , and a lth ou gh fu nc tion m ay be res to red su ff icien tly tope rm it lig h t w ork a fte r a m on th , ph ysio the rapy m ay b e neces sary fo r m u ch lo nge r.Exc is ion o f th e pa te lla -T h is ope ra tio n g ives sho rt- te rm resu lts sim ila r to th ose ob ta in edw hen it is pe rfo rm ed fo r frac tu re . F u nc tion is se ldo m resto red com p lete ly to norm a l, bu tthe r isk th at a second o pe ra tion m ay la ter b eco m e n ecessa ry is rem oved . T he app ea ran ceo f the knee is usua lly qu ite goo d , bu t occas iona lly the co n tou r o f th e kn uck le o f th e fem u rbecom es o bv io us and th is is m ost u nsigh tly .

T he p ate lla , in yo ung e r p eo p le , can usua lly be d issected o u t w ithou t in ju r ing the q uadricepsex pansio n to such an ex ten t tha t it need s repa ir. In o ld er p atien ts m ore f ib res are inse rtedin to the cen tra l pa r t o f th e b one an d it m ay b eco m e so a ttenu ated tha t su tu re is d esirab le .R esto ra tion o f func tion often tak es ra the r long e r than after rem ova l o f th e a rticu la r ca r tilag e,and m an ipu latio n m ay be neces sary to resto re fu ll flex io n .

R E S U L T SW e have reco rds o f the con d ition o f th e a rticu la r ca rtilage as seen a t o pe ra tion in six ty -f ive

knees w ith m arked chon drom a lac ia. T hose w ith fran k o steo a rth r itis a re de libe rate ly ex clu dedfrom th is su rvey .

R e fe rence has a lready b een m ade u nde r the head ing o f na tu ra l h is to ry to the n ine teenknees in w hich the ca rtilage w as le f t u n tou ched . T h e rem ain ing fo rty -s ix w ere treated byrem o va l o f a ll o r pa r t o f the a r ticu lar ca rtilage , o r by ex cisio n o f the p a tella . T he pa rticu larsare d e tailed in T ab le V an d th e re su lts a re su m m aris ed in T ab le V I.

T he resu lt ha s b een ca lled goo d w h en the pa tien t is ab le to fo llo w h is u sua l occupa tionan d le ad an ord in ary life w ith ou t d iscom fo rt. T he kn ees m ay n o t be pe rfect bu t they do s tan dup to any ord in ary stra in . F o r exam p le, th e pa tien t in C ases 1 and 26 , w ho h ad a rticu lar



15/19

P . W IL E S , P . S . A N D R E W S A N D M . B . D E V A S 10 9T A B L E V

O P E R A T IV E T R E A T M E N T O F C H O N D R O M A L A C IA (T o A P R IL 1 9 5 5 )

n u m b e r A ge Se x O c cup atio n D ate of 4T im e to D a teorm a l la st R esu lt C om m entiagn os is op e ra tion weeks { 149}seen

O N E - T H I R D O F A R T IC U L A R C A R T IL A G E R E M O V E DOperat ion on b oth k n e es.1 2 2 M S an ita ry C hon drom a lacia F eb . 195 2 16 M ay 19 55 G o o d T his on e cause s noeng ineer trou b le . S ee C ase 2 6

Osteochondr i t is L oose fragm ent r em o v ed2 16 M B an k c lerk d issecan s: O ct . 19 53 22 A u g . 1 95 5 G o od from fem ora l c ond yle .C hon drom a lacia N ow has no disab ilityO bese . N o w p up il nurse3 16 F C le rk C ho ndrom alac ia D ec . 1953 8 O ct. 19 54 G o od an d kn ee causes n o tro ub le

S a le s S u pe rf ic ial sca r t e n d e r .4 37 M C hon drom a lacia M ay 195 4 13 June 195 5 G o o dm anage r N o o the r sy m pto m sC ho ndrom alac ia. T orn sem iluna r ca r tilag erem oved . Patel la exc ised

5 41 M H eavy lor ry T or n m ed ia l Ju n e 195 4 - - B ad f our m onth s la te r fo rriver semilunar con tin u ing p ain an dcartilage d isab ility . (See C ase 44 )Me t a l6 2 1 M C hon drom a lacia A ug . 1 954 14 A ug . 19 55 G oo d N ow has no sym p tom sm ach i n i s t

T W O - T H I R D S O F A R T IC U L A R C A R T IL A G E R E M O V E DP a tel la e xcised eigh t

7 15 M S cho o l C h ond ro m a lac ia M ar. 1 952 - - B ad m on ths la ter . O the r k neea lso affec ted . S ee C ase 35T orn m ed ial Sem iluna r ca rtilage

8 1 9 F - sem i l u n a r S ep t . 19 53 8 O ct . 195 4 G o o d normal.cartilage N ow no sym p tom sT o rn m ed ia l S lo w to r ecover

9 1 6 F S choo l sem ilun a r O c t. 195 3 50 A ug . 195 5 G ood b u t n owcart i lage free o fy m p t o m sM o r e th an 1 00 c ar tila gin -10 27 M D o cto r M ultip le N ov . 19 53 10 O c t. 19 54 G ood ous loose bod ies rem oved .lo ose bo d ie s N o w h as occasion al ache

T orn m ed ia l S em ilu na r car t i lageIndus tr ial sem ilun a r N o v . 195 3 28 M ay 195 4 - n o r m a l .1 1 24 M chem ist ca r tilag e N o w in S ou th A fricaP T T or n m e d ia l12 2 1 F sem ilunar A p r . 1954 8 S ep t. 19 55 G o od N ow prac tic a lly n o rm alin struc to r ca r tilag e

S low to regain goodFla t fu nc tion bu t n ow h as13 45 M C h o n d r o m a l ac i a M ay 195 4 5 0 J u n e 1 955 G o o dm an ag e r on ly s ligh t sw ell in gaf ter m uc h e xe rcis eS em ilun ar c ar tilag eT or n s em ilu na r14 23 M R .A .F . June 195 4 8 M ay 19 55 G oo d no rm al. N ow ha scar t i lage occas lona l st i f fness

Tor n se milu na r c artila geT orn m ed ial rem ov ed . N ow f ree of15 1 8 M S tuden t sem iluna r June 195 4 6 A ug . 19 55 G oo d sym p tom s b u t o th er kn ee

cart i lage beg inn ing toau setrouble

V O L . 38 B , NO . 1, F E B R U A R Y 1956


16/19

1 10 T H O M A S F A IR B A N K B IR T H D A Y V O L U M ET A B L E V-con t i nued

T i m e to D a ten u m b e r A g e S ex O ccu pa tion P re-op era tiv e D a te o f n o rm a l la st Resu l t C o m m e n tiag nos is op era tion w eek s seen

T W O - T H I R D S O F A R T I C U L A R C A R T I L A G E REMOVED con t i n u e dS ch oo l an d I Torn m ed i a l

1 6 2 8 M ga m e s se m ilu n ar A u g. 195 4 1 2 Ju n e 19 55 G oo d S o m e tim es sw e lls af term uc h ex erc isem aste r c ar tilage________________________________________________________________________ T o rn cr u ciate R ep air ofm ed ia l liga m en t;

1 7 43 M Inspec to r and m edia l A ug . 1954 - Jun e 19 55 B ad m ern scec tom y . K neede te rio ra ting and sw ellsf taxes ligam en t a fte r m o derate ac tiv i tyT o m m edia l F ree o f a ll sy m pto m s

1 8 2 0 M S tu d en t se m ilu n ar Jan . 19 55 8 M a r. 195 5 - tw o m onth s a f tercar t i lage operat ionA t w o rk b u t still la cks1 9 37 M G arage L o ose bod ies M ar. 19 55 - June 1955h a n d - 25 degrees f lex io n

Loose body and A rticu lar ca r tilag e20 28 M C lerk o ste och on d r itis M a y 1 955 - - - rem o ved from fem urd isse ca n s also

21 2 2 M L ib rar ian C ho nd rom ala cia M a y 19 54 6 M ay 19 55 G o od K ne e som etim e s feels s tiffT o rn m ed ia l

22 3 3 M T ele p h on e se m ilu n ar Ju n e 1 955 - - - T orn sem iluna r ca rtilageen g inee r car tilage

A L L A R T IC U L A R C A R T IL A G E R E M O V E DT orn m ed ia l O n ly sym p tom is23 - F H ousew ife sem iluna r D ec . 19 51 16 A ug . 195 4 G oo d ach in g in

car tila ge w et w ea th erG ross v illou s syn ov itis .V e ry slow recove ry bu t24 27 F S ec reta ry C hon drom a lacia A u g. 1 952 - F eb . 1 95 4 F air no w is usua lly free o f

sym pto m s an d can w a lkm iles; o ccasion a l ep isod eso f s ti ff ne ss an d sw el l ing

T orn m ed ia l S ubseq uen tly had2 5 15 F T e lepho n ist sem iluna r Ju ne 1 9 5 3 - - B ad pa tella exc isedca rtilage e lsew he re

O pe ra tion o n bo th knees.2 6 25 M S an ita ry C hondrom alac ia M ar. 195 4 12 Ju n e 19 55 G oo d N o trou b le excep t so m ee nginee r p ain afte r ru nn ing ab o u ttw e lve m iles. S ee C a s e 1

S em iluna r c artila geTorn me d i a l2 7 22 F N u rse sem ilu n ar M ay 1 954 12 Ju ly 19 55 G oo d no rm al. O nly sy m p t o mis so m e ach ing a fte rc art ila ge k n eel in g for lon g

T ech n i ca l28 36 F C h ond ro m a lac ia S ep t. 19 54 2 7 A ug . 1955 G ood N ow has no sym ptom sta ff B .B .C .S till m uc h d isa bility ;C an t een2 9 43 F C h ond ro m a lac ia O c t. 19 54 - Ju ly 19 55 B ad re q u ire s e xcis ion o fm anage res s pa te lla

30 28 M T ransp ort C h ond ro m a lac ia F eb . 1 955 6 Ju ly 1 955 G o o d O nly sym ptom is sw ellinge xe cu tive after sev era l se ts of te n n is31 24 F S ecre ta ry C hon drom a lacia A p r. 1 955 - Ju ly 1955 - N o pa in bu t has no t ye te gain ed fu ll flex ion



17/19

P . W IL E S , P . 5 . A N D R E W S A N D M . B . D E V A S 11 1T A B L E V-con t i nued

n u m b e r A g e S ex O ccupa tion P re -op era tive D ate of T im e to D ateo rm al last R esu lt C om m e n tiag no sis o peratio n (w ee ks) seen

P A T E L L A E X C ISE D32 3 4 F C lerk C h ond rom alacia Jun e 19 48 1 6 M ay 1955 G o od A ches if ove rd oes it33 32 M A ir s tew ard C hon drom alac ia Feb . 1 950 - Jun e 19 50 - C an not be traced3 4 25 M Salesm an C hond rom alac ia A ug . 1 950 ? S ep t. 195 4 G ood N ow ha s n o sym pto m s

P re vio us re mo va l t wo -3 5 l5 tC ho ndrom alac ia I t hi rd s c ar ti la ge rightI M S chool pa te lla . pa te lla (C ase 7). N owov . 19 52 20 S ep t. 195 4 F a ir1 C h ondro m alac ia gn B oth knees3 6 16J le ft p ate lla c l im b in g lad d e rsar . 1 953 ? S e p t. 195 4 F air a ch e if h e stan d s lon g ,and do es no t like

Tran sp lan ta tion pa te llaR e curren t tend on. S low reg ain ing37 17 F S hop dis lo ca tion w ith Jan . 1953 60 M ay 19 55 F air fu nc tion . N o w finds

ass is tan t cho ndrom alac ia k nee ling d iff icu lt an dso m etim es sw ells38 3 4 F H ousew ife C ho ndrom alac ia S ep t. 195 3 24 S ep t. 1954 G o od A ches afte r sittin g fo r lo ng

Severa l p rev ious opera -tlo n s on sam e k n ee39 2 4 F H ou sew ife C h on d ro m a la cia M a y 19 54 N o J u ly 1 95 5 B ad else w h ere . U n lik ely e verto ge t good funct ion

4 0 3 3 F Salesw om an C ho ndrom alac ia June 195 4 - A ug. 1955 G o od c 10 degr ees f lex ion.A ches in co ld w ea therL ack s 5 0 d e gre es flex ion41 27 M E ng ine er C hon drom alac ia A ug . 1 954 24 Jun e 1 955 F air and h as diffic u lty inkneel ing

C h o n d r o m a l ac i a ; T ransp lan tatio n p ate lla r4 2 28 F Invo ice o ld recurren t A ug . 1954 1 2 A p r. 195 5 G ood ten don 1 945 .c lerk d islo catio n N ow has no sy m pto m s

H otel C hondrom alac ia ; O c t. 1954 - M ay 195 5 F a ir S till sw e lls a fter4 3 40 F m a nag ere ss loo se bo die s exe rciseS ti lla ch e san d occ asion a lly

4 4 42 M H eav y lo r r C ho ndrom alac ia O c t. 1954 1 2 A ug . 195 5 F a ir g ive s w ay . D riv ing ad rive r ligh t van . S ee C ase 5M u c h muscle wast in g45 19 F Teaching C h o n d r o m a l ac i a A pr. 195 5 - Ju ly 19 55 - b efor e o per ation and h asstud en t no t ye t ga ined fu ll co n tro lB ack a t w o rk b u t h as46 49 M C le rk C h on d ro m a la cia A p r . 1 955 - Ju ly 19 55 - no t y e t fu ll flex io n

ca rtilage rem oved from bo th p ate lla e , h as h ad to g iv e up h is h obb y o f lo ng-d istan ce ru nn in gbecau se th e knee tha t had all the ca rtilage rem o ved hurts a fte r abou t tw e lve miles .R em ova l o f car tila ge -T h ir ty -on e knee s h av e b een trea ted in th is w ay , n ine teen be ing c la ssif iedas goo d , o ne as fa ir , five a s bad , and s ix a re recen t o r un kno w n . O n ly one has been ca lledfa ir becau se a m ode rate ea r ly re su lt u su ally de te rio ra tes qu ick ly and b ecom es bad . T he excep tionis th e pa tien t in C ase 24 w h o h ad a gross v illous syno v itis and has been ve ry slow to reco ve r.T hree yea rs a fte r the ope ratio n sh e is u ncon scio us o f he r kn ee m os t o f th e tim e , and usua llyV O L . 38 B , NO . 1, F E B R U A R Y 1956


18/19

1 12 T H O M A S F A IR B A N K B IR T H D A Y V O L U M Eca n w alk m ile s w ithou t any tro ub le, b u t o ccasion a lly the re a re ep iso des o f stif fn e ss and sw ellin glastin g a fe w days. T he pa tien ts w ith b ad resu lts have e ithe r h ad th e p a tella exc ised la te r o ra re like ly to requ ire fu rth er o pe ra tion .

T h e re su lts becom e le ss satisfacto ry as the am ou n t o f ca r tilag e rem o ved inc rea se s.H ow ever , the bad re su lts in clu de tw o pa tien ts ag ed fo rty - th ree , and tw o w ith ve ry ex tens ived egene ra tion a t the ag e o f f ifte en . T he o lde r pa tien ts , w h o are approach in g the ag e ofos teo arth r itis , a re p rob ab ly b ette r trea ted by ex cis io n o f the pa te lla . V ery you ng p atien tsw ith ex tensiv e deg en era tion a re like ly to have ea rly invo lvem en t o f th e fem oral a rticu la rca r tilag e and a lastin g resu lt is im prob ab le w ha teve r is don e . B e tte r se lec tion o f cases fo rrem ova l o f ca rtilage shou ld im p ro ve th e re su lts .

T A B L E V IR E SU L T S O F O PE R A T IO N ( F o R T Y - s i x C sas)

R e su l t

N ature of opera tio n R ecen tG o od Fa ir B ad o r T ota lu n k n o w n

A rticu lar ca rtilage rem oved :one-th ird . . . 5 - 1 - 6two-th irds . . . 9 - 2 5 16completely . . . 5 1 2 1 9

P a tel la exc ise d . . . S 6 1 3 1 5T o t a l . . . . 24 7 6 9 4 6

T h e o n ly co m p arab le fig u res a re th ose g iven by K arlson (19 40) w ho re -ex am ined th epa tien ts o pe ra ted up on in A lem ans clin ic on e to tw en ty y ea rs b efo re , bu t he d id no t g ivede ta ils o f the am oun t o f car tilage rem oved . O f fo r ty -eig h t knee s w ith chon drom a lacia (bu tw itho u t frank os teo arth r itis), th ir ty - tw o h ad m ad e a fun ctio na l reco ve ry , th ir te en h ad im p ro vedand th ree had no t im proved ; s even pa tien ts (it is n o t sta ted in w h ich group ) h ad rad io log ica lev idence o f o s te o ar th ri ti s.E xc is io n o fth ep ate lla -T he pa te lla has been rem oved fo r chon dro m a lacia o n fif te en occasio ns.T h e resu lts are no t str ik ing ly g ood bu t th ey com p are w ith those o f the co rre spo nd in g o pe ra tionfo r recen t frac tu re, w h ich a re no t a s b rillian t a s is co m m o nly su ppo sed . S co tt (1 94 9) fo llow edup a n um b er o f m en w ho had been op era ted up on in the R oya l A ir F o rce during th e w ar.H e fou nd tha t o n ly 5 pe r cen t rega rd ed th em se lves as hav ing n orm al k nees; the rem ain de r hada var iety of t roub les, fo rxam ple , 79 p er cen t com p lain ed of pa in and 55 pe r cen t sa id tha tthey w ere u nab le to w a lk dow ns ta irs no rm a lly .

T he lo ng-te rm resu lts o f the m o re conse rva tive ope ra tio n w ill n o t be kno w n fo r so m eyea rs . I f co m ple te rem ova l o f a ll deg en era te car tilage p rev en ts the reac tive chang es th at le adto os teo arth r itis , it ma y w ell becom e th e p ro cedu re o f cho ice in p ro pe rly selec ted cases.

S U M M A R Y1 . C hon drom a lac ia, so m e tim es a p recu rso r o f os teo arth r itis , is p re sen t in th e a r ticu la rcar tilage o f the pa tella o f m ost peop le b y th e age o f th irty ; it cau ses sym ptom s in o n ly a few ,an d it give s r ise to oste oar th ritis in fe w e r still. It m ay prog re ss slo w ly o r qu ick ly bu t the reis no clin ica l m e tho d of a sse ssin g the p ro gno sis at an ear ly stage .

T H E JO U R N A L O F B O N E A N D J O IN T S U R G E R Y


19/19

P. W IL ES , P . 5 . A N D R E W S A N D M . B . D E V A S 11 32 . T he earlie st ch ange is sw ellin g of th e car tilage assoc ia ted w ith a decrease in the cho ndro itinsu lphu ric ac id con ten t o f th e m atr ix . L a te r the ca rtilage f i ssures and flakes o ff to ex po se th ebo ne , and the re a re reac tive chang es in the ca rtilage , b one and sy nov ial m em b rane . T h eprocess is de sc rib ed and the e tio logy d iscussed .3 . T he sy m pto m s, sig ns an d trea tm en t a re d iscussed . O pe ratio n , w h ich h as been pe rfo rm edo n ly w hen the re a re d isab ling sy m pto m s, m ay co nsist in rem ov ing pa rt o r the w ho le o f thea r ticu lar car tilage , o r in ex cisio n of the pa te lla . T h e resu lts in fo rty -six knees a re g iven .It is a p leasu re to th an k M r M . T u r n ey for h is h e lp w ith th e m a n y p h oto gra p h s, an d M r P . R u n n icles fo r th ephotomicrographs .

R E F E R E N C E SA L E M A N , 0 . (19 28): C hondrom alac ia p osttraum atica pa te llae . A c ta C hiru rg ica S cand inav ica , 6 3 , 14 9 .A X H A U S E N , G . (19 19 ): D ie u m sch rieb en en K n or p el-K n oc h en la sion en d e s K n ie gelen k s. B e rlin er K lin isch eWochenschr i f t , 56 , 265 .B E N N I N G H O F F , A . (1 925 ): F o rm un d B au d er G e len kkn orpe l in ih ren B ez iehun gen zu r F u n k tion . Z eitsch rif tf {252}r e llfo rsc hu ng u nd M ikrosk opisch e A n ato m ic , 2 , 7 83 .B U D I N G E R , K . (l9 06):O be r A b losung v on G e lenk teilen und ve rw and te P ro zesse . D eu tsche Z e itsch rif t f {252}rC hiru rg ie , 84 , 3 11 .B U D I N G E R , K . (1 908 ): O b e r tr au m atisch e K n or p elr isse im K n ie gelen k . D e u tsch e Z eitsch rif t f {25 2}r h iru rg ie ,9 2 , 51 0 .C A V E , E . F ., R O W E , C . R ., an d Y E E , L . B . K . (194 5): C h on d r om ala cia o f th e P a tel la . S u rge ry , G yn e colog yand O b ste trics , 8 1 , 446 .C H A K L I N , V . D . (193 9): In ju rie s to the C artilages o f th e P a te lla and th e F em oral C on dy le . Jo u rn a l o f B on eand Jo in t S urge ry , 21 , 13 3 .G R A Y , C . (19 48): C hondrom alac ia P a te llae . B ritish M ed ica l Journ al, i, 427 .H A R R I S O N , M . H . M ., S cH M ow lcz , F ., an d T R U E T A , J . (195 3): O steoa rth ritis o fth e H ip : A S tu d y ofth e N atu r ean d E volu tion of th e D isease . Jo urna l o f B one and Jo in t S urgery , 35 -B , 5 98 .H I R S C H , C . (19 44): A C ontr ibu tio n to th e Pa th ogenesis o f C hon dro m a lacia o f the P a tella . A c ta C h iru rg icaS cand inav ica , 9 0 , S upp lem entum 8 3 .K A R L S O N , S . (1 940 ): C h ond rom a lac ia P a te llae . A c ta C h iru rg ica S cand in av ica, 83 , 34 7 .K E Y , J . A . (19 34): C on tu sion o f C a rtilage as an E tio lo g ical F ac to r in C hron ic A rth ritis . S u rg ery , G yn eco logyan d O bste tric s , 58 , 1 66 .L A W E N , A . (19 25): K n orpe lresek tion be i f issu ra le r K no rpe ldeg en era tion de r P a te lla-e ine F r {25 2} hop era tion d e rA rthr itis de fo rm ans . B e itr {22 8}ge ur K lin ischen C hiru rg ie , 134 , 26 5 .L U D L O F F (1 91 0): C it. { 24 8} wre1 93 6).M A C N A B , 1. (1952) : R ecurren t D is locatio n of the P a tella . Jou rna l o f B o ne and Jo in t S urge ry , 34 -A , 9 57 .M A T T H E W S , B . F. (1 953): C o m position o f A rticu lar C artilag e in O steoarth r itis. B ritish M ed ica l Journa l, ii, 660 . { 2 1 6 } W R E , A . (1 936 ): C h ond rom a lac ia P a te llae . A c ta C h iru rg ica S cand in av ica, 7 7 , S u pp lem en tu m 41 .S co T T , J. C . (1 94 9): F rac tu re s o f th e P a tella . Jou rna l of B one and Jo in t S u rge ry , 31 -B , 76 .S M I T H - P E T E R S E N , M . N . (19 48): E volu tion of M o uld A rth rop las ty of the H ip Jo in t. Jo urna l o f B one an dJo in t S u rg ery , 3 0 -B , 59 .S O T O - H A L L , R . (1 945 ): T rau m a tic D egene ra tion o f the A rticu la r C a rtilag e o f the P ate lla . Jou rna l o f B on eand Jo in t S u r ger y , 2 7 , 4 26 .W I B E R G , G . (1941 ): R oen tgenog raph ic and A natom ic S tud ies on the F em oro pa te lla r Jo in t. A c ta O rthopaed icaS can d inav ica , 12 , 3 19 .

V O L . 3 8 B , NO 1, F E B R U A R Y 1 9 5 6H

patellar cartilage

Documents