6 P H Y S I O T H E R A P Y JUNE, 197s TOTAL KNEE REPLACEMENT b y D R . J. P . V A N V U R E N M .B ., B .C h., F.R.CJS. C on su lting O rthopaedic Surgeon, M ed ical S c h o o l, U n iversity o f W itwatersrand and Strydom H osp ital. T h e c o n c e p t o f k n e e jo in t re p la c e m e n t is n o t new. R e p la c e m e n ts w ith e n d o p ro sth e s e s w e re a tte m p te d as fa r b a c k as 1900. R e c e n t a d v a n c e s in th e d e v e lo p m e n t of b io lo g ic a lly s u ita b le m a te ria ls a n d th e a p p lic a tio n of b io m e c h a n ic a l p rin c ip le s in th e d esign o f e n d o p ro sth e s e s, h a v e o p e n e d a p ro m is in g field in re p la c e m e n t a r th r o ­ p la s ty . I t m u st be n o te d t h a t th e k n e e re p la c e m e n t e n d o ­ p ro s th e s e s w h ic h a re a v a ila b le to d a y o n ly re p la c e th e fe m o ro -tib ia l a r tic u la tio n a n d a re th e re fo re n o t true to ta l k n e e re p la c e m e n ts. P a te llo -fe m o ra l p a in a n d a r tic u ­ la tio n p ro b le m s a re o fte n a c o m p lic a tio n a fte r a su c c ess­ fu l k n e e jo in t re p la c e m e n t a rth r o p la s ty , a n d re se a rc h to r e p la c e th is a r tic u la tio n is in p ro g re s s a t th e p re s e n t tim e. B a sic a lly k n e e jo in t re p la c e m e n t e n d o p ro sth e s e s fa ll in to tw o c ateg o rie s: (i) T h e H in ge T ype c onsists o f in tra m e d u lla ry fe m o ra l a n d tib ia l stem s lo ck e d to g e th e r a t th e k n e e jo in t w ith a m ec h a n ic a l h inge a rra n g e m e n t. T h is h inge m a y re p la c e th e fe m o ra l a n d tib ia l c o n d y le s p a r ­ tia lly o r to ta lly . (ii) T he R esu rfacin g T y p e o f p ro sth e sis re p la c e s the a rtic u la tin g su rfa c e s o f th e fe m o ra l a n d tib ia l c o n d y le s p a rtia lly o r to ta lly . T h e m a te ria ls u se d in th e m a n u fa c tu re o f the c o m ­ p o n e n ts v a ry w ith th e p a r tic u la r design a n d ty p e of p ro s th e s is . T h e h in g e ty p e o rig in a lly c o n sisted o f C o .C r. S te el c o m p o n e n ts, b u t re c e n t ty p es in c lu d e p la s ­ tic c o m p o n e n ts. T h e re s u rfa c in g ty p e o f e n d o -p ro th e s is by a n d la rg e c onsists o f fe m o ra l C o .C r. Steel a llo y c o m ­ p o n e n ts a n d d istal hig h d e n sity p o ly e th y le n e tib ia l c o m ­ p o n e n ts . In dication s T h e p rim e in d ic a tio n fo r k n e e re p la c e m e n t a r th r o ­ p la s ty is a t p re s e n t c o nfined to jo in t fa ilu re in p a tie n ts su ffe rin g f r o m r h e u m a to id a rth r itis , as a n a lte rn a tiv e to k n e e fu sio n . R e p la c e m e n t a r th r o p la s ty m a y a lso be c o n sid e re d in se lected cases o f o s te o -a rth ritis o r in p a tie n ts in w h o m h e m i-a rth ro p la s ty o f th e k n e e h a s fa ile d . T h e p a tie n ts w ith k n e e jo in t f a ilu re u su a lly h a v e tw o f e a tu re s in c o m m o n , viz., p a in a n d m e c h a n ic a l in ­ s ta b ility . T h e m e c h a n ic a l d e ra n g e m e n t m ay b e d u e to lig a m e n to u s in sta b ility o r c o n tra c tu re , or in s ta b ility d u e to jo in t s u rfa c e a n d b o n e d e stru c tio n . T h e p a tie n ts o fte n p re s e n t w ith a ll th e a b o v e fe a tu re s o f jo in t fa ilu re p re ­ se n t in o n e o r b o th k n e e jo in ts. B e fo re th e a d v e n t o f k n e e jo in t re p la c e m e n t so m e 6 y e ars a g o , o n e w o u ld h a v e offered th e p a tie n t a knee fu sio n w h ic h w o u ld h a v e p ro v id e d him w ith a sta b le p a in le ss k n e e. In m a n y cases th is is still th e p ro c e d u re o f c h o ic e today. A t p re s e n t to ta l k n e e re p la c e m e n t m ay offer the p a tie n t th e p o ssib ility o f a s ta b le , p a in fre e , y e t m o b ile knee. P a tie n ts in w h o m re p la c e m e n t a rth r o p la s ty is c o n ­ sid e re d m a y be classified on a f u n c tio n a l basis in to th ree g ro u p s: (i) T h o s e le a d in g m o stly a w h e e lc h a ir existe n ce b u t w h o a r e a b le t o tra n s fe r in d e p e n d e n tly . (ii) T h o s e usin g w a lk in g aid s b u t w ith a lim ite d walk, ing d ista n c e d u e to p a in a n d in sta b ility . (iii) A m b u la n t p a tie n ts w a lk in g w ith o u t su p p o rt, but w ho a re fo rc e d to use so m e m e a n s o f s u p p o rt dUe to in c re a s in g p a in a n d in stab ility . T h e p h y s io th e ra p e u tic e x p e rie n c e th a t we h a v e gained is confined to p a tie n ts w h o have h a d o n e o f th e follow, ing ty p es o f a rth ro p la s ty : (i) F re e m a n -S w a n so n . (ii) G e o m e d ic . (iii) P o ly c en tric. O utline o f O perative P roced ure. A n a lm o s t s tra ig h t m ed ia n p a r a p a te lla r sk in incision is u se d to e x p o se th e jo in t cap su le a n d u n d e rly in g struc­ tu re s . T h e in cision e x te n d s fro m th e u p p e r b o rd e r 0f th e s u p r a p a te lla r b u rsa to th e tib ia l tu b e rc le . T h e joint is e x p o se d by d islo c a tin g th e p a te lla la te ra lly . T h e p ro sth e se s a re in se rte d a fte r b o n e re sec tio n of th e fe m o ra l a n d tib ia l co n d y le s. T h e a m o u n t o f bone resected w ill differ w ith th e ty p e o f p ro s th e s is used. T h e p ro s th e tic c o m p o n e n ts a re u su a lly fixed w ith bone cem ent. T h e s u b c u ta n e o u s stru c tu re s a re c losed w ith non­ a b s o rb a b le su tu re s. R o u tin e su c tio n d ra in a g e is used. A tte n tio n to c a re fu l skin c lo s u re is essential. T h e lim b is p la c e d in ex te n sio n in a R o b e r t Jones B a n d ag e . P ost-op erative R egim e. T h e p a tie n t is n u rse d w ith th e lim b e le v ate d on p illo w s f o r tw o to th re e days. T h e d re ssin g is removed on th e th ird d a y a n d th e w o u n d in sp e c te d f o r a n y signs o f slo u g h in g . T h e su c tio n d ra in a g e is u s u a lly re m o v e d by th e third day. O n th e th ird day th e lim b is p u t in to a T h o m a s Splint w ith a P e a rs o n a tta c h m e n t a n d p h y s io th e ra p y is com­ m enced. C om p lication s o f Im p ortan ce to the Physiotherapist „ (i) W ound D eh iscen ce. T o ta l w o u n d d e h isce n ce may o c c u r as an e a rly c o m p lic a tio n , th a t is. o n th e third d a y w hen flexing o f th e knee is c o m m e n c e d , b u t may o c c u r a t a n y tim e u p to th e te n th d a y . T h is com plica­ tio n u su a lly is fo u n d in p a tie n ts w ith rh eum atoid a rth r itis w h o h a v e e ith e r h a d c o rtiso n e tre a tm e n t in the p a s t o r a re still b e in g tre a te d w ith c o rtiso n e . I t is w ell k n o w n t h a t d e la y ed w o u n d h e a lin g o c cu rs in p a tie n ts w ith rh e u m a to id a rth ritis . (ii) Superficial Skin Slou gh in g. T h e c o m p lic a tio n , in o u r e x p erien c e , is th e re su lt o f to o tig h tly a p p lie d skin su tu re s. T h e c o m m o n e s t site o f slo u g h in g is b e lo w the p a te lla . T h e a b o v e c o m p lic a tio n s a re im p o r ta n t f r o m the p h y s io th e ra p e u tic p o in t o f view . It h a s b e en o u r ex­ p e rie n c e t h a t su c h c o m p lic a tio n s w ill re ta r d th e post­ o p e ra tiv e r e h a b ilita tio n o f th e p a tie n t a n d m a y lead to loss o f flexion. W e fe el it is im p o r ta n t t h a t th e surgeon a n d th e p h y s io th e ra p is t in sp e c t the w o u n d to g e th e r on th e th ird d a y a n d e v ery d a y till th e te n th d a y . I f early sk in slo u g h in g is p re s e n t th e su rg e o n sh o u ld g u id e the p h y s io th e ra p is t as to th e ra n g e of flex io n a llo w e d by R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) jUNlE 1975 F I S I O T E R A P I E 7 ihe knee a n d o b se rv in g th e w o u n d fo r signs of flexing th u s a llo w in g flexion w ith in sa fe lim its. T h e deh*ce f flexion m ay be in cre ased o r d e c re a s e d a cc o rd - rangtn the c o n d itio n o f th e w o u n d . in"- la l w o u n d d e h isce n ce m u st be tre a te d by im m e d ia te "*? r i n e w h e re a fte r th e p h y s io th e ra p e u tic m a n a g e m e n t be d irected by th e su rg e o n , n h i s c e n c e o f th e jo in t c a p s u le w ith o u t skin in volve- t m a y o c cu r. In o u r e x p erien c e th is c o m p lic a tio n me" a ffect th e e a rly p o s t-o p e ra tiv e p h y s io th e ra p y . d,oeefui o b s e rv a tio n of the k n e e is n e c e ssa ry to a v o id ^ a/1 dchiscence. O n c e w o u n d h e a lin g is c o m p le te , the tient m ay be le ft w ith an u n s ta b le k n e e d ue to ^ h i s c e n c e o f th e d e e p e r stru c tu re s. T h e cau se o f this in s ta b ility is u s u a lly la te ra l d is lo c a tio n o f th e p a te lla '""T h e 'a b o v e a re th e only c o m p lic a tio n s w e h a v e en- ntered in o u r sm a ll series o f sixteen to ta l knee re- C l a c e m e n t s . T h e fo llo w in g a re so m e o f th e c o m p lic a ­ tions which have b een re p o rte d in lite ra tu re : (i) I n fe c tio n — su p erficia l a n d d eep . (ii) D is lo c a tio n o f c o m p o n e n ts . (iii) In sta b ility d u e to in a d e q u a te lig a m e n to u s s u p p o rt. (iv) R e sid u a l p a te lla r p a in . (v) P e r o n e a l n e r v e p a lsy . The Physiotherapy Management of Geomedic and Polycentric Knee Prostheses b y K A T H R Y N LESLIE, B.Sc. (P hysiotherapy) (W itwatersrand) 1. P R E -O PE R A T IV E M A N A G E M E N T . This is an im p o r ta n t p e rio d fo r th e P h y s io th e ra p is t, as it gives h e r n o t o n ly a c h a n c e to assess th e p a tie n t, but also tim e to g ain th e p a tie n t’s c o -o p e ra tio n a n d confidence. To date the to ta l k n e e re p la c e m e n t a rth ro p la s tie s h a v e ly been p e rfo rm e d on p a tie n ts se verely affected w ith .■^ieumatoid A rth ritis . T h is m e a n s n o t o nly is th e k nee joint affected, b u t th e re is u s u a lly se v e re in v o lv e m e n t of other jo in ts. T h is m u s t be c o n sid e re d t h r o u g h o u t the treatm ent p e rio d as th ese p a tie n ts a re g e n e ra lly severely disabled a n d h a n d ic a p p e d . 1. i. Assessing the patient. A ttention is d r a w n to th e f o l l o w i n g : (a) A ssessm ent o f A ll Jo in ts. T h is is im p o r ta n t as if fo r e x a m p le th e h a n d s o r e lb o w s a re severely affected by a r th ritis th e p a tie n t m ay b e u n a b le to m an a g e w a lk in g a p p lia n c e s a n d th e o p e ra tio n w o u ld be p o stp o n e d u n til th is d isa b ility h a d been c o rre c te d as fa r as p o ssib le , e n a b lin g b e tte r fu n c tio n . P a rtic u la r a tte n tio n m u st be p a id to th e s tre n g th of th e h ip a n d o p p o site k n e e m uscle g ro u p s as these m ay re q u ire s tre n g th e n in g in o rd e r fo r th e a m b u ­ la to ry p h a se to be su c c essfu l. ft>) A sse ssm e n t o f th e In v o lv e d K n e e Jo in t. T h e stre n g th o f th e q u a d ric e p s e sp e c ia lly v a stu s m edialis, is u su a lly v ery w e ak w h ic h is d u e to a flexion c o n ­ tra c tu re o f the k n e e jo in t. O th e r d e fo rm itie s, su c h as a genu v a r ru s o r v a l­ gum , m ay b e p re s e n t as w ell. T h e re m ay be in s ta b ility of th e k n e e jo in t. (c) G a it. I f the p a tie n t is a m b u la n t th e ty p e o f w a lk in g a id u se d a n d th e g a it p a tte rn m u s t be n o te d . I. ii. A n explanation o f the treatm ent procedure is o u t ­ lin e d to th e p a tie n t. T h e p a tie n t is ta u g h t a s tro n g iso m e tric q u a d ric e p s c o n tra c tio n e m p h a sisin g ‘lo c k in g ’ th e k n e e a n d a v o id in g a knee lag . I t is stressed t h a t th e p o s t-o p e ra tiv e success w ill d e p e n d on th e p a ti e n t ’s m o tiv a tio n a n d h a rd w o rk . II. P O S T -O P E R A T IV E M A N A G E M E N T 11. i. Im m ediate post-operative stage. (D ay 1 to d a y 5). T h e p a tie n t re tu rn s f r o m th e a tre w ith th e leg k e p t in e x te n sio n by e ith e r a R o b e r t J o n e s b a n d a g e o r a fu ll le n g th P la s te r o f P a ris c y lin d e r. A p o rto -v a c d ra in h as been _ in se rte d a n d is re m o v e d 36 to 48 h o u rs p o st- o p e ra tiv e ly . A n a n tib io tic d rip is given in tra v e n o u s ly fo r the first 48 h o u rs. T h e first tre a tm e n t consists specifically o f lo ca liz ed b re a th in g , c irc u la to ry exercises, a n d iso m e tric q u a d r i­ ceps c o n tra c tio n s. W h en th e p a tie n t is m o re c o -o p e ra tiv e he m u s t p a lp a te th e c o n tra c tio n s a n d exercise fo r te n m in u te s h o u rly . T h e p a tie n t p ro g re s se s to s tra ig h t leg ra isin g w h e n th e p o rto -v a c d r a in is re m o v e d . T h e p h y s io th e ra p is t m u s t c heck th a t n o t o n ly h ip flexors a re b e ing u se d b u t p a rtic u la rly q u a d ric e p s . S tre n g th e n in g e x ercises fo r a ll h ip m u sc le s o f b o th legs a re a d d e d to th e r o u tin e a n d p ro g re s se d as th e p a tie n t im p ro v e s. G e n tle k n e e flexion exercises to a b o u t 20° a re b e g u n by day 3. O n d a y 5 th e R o b e r t Jo n e s b a n d a g e is r e ­ m o v ed , th e w o u n d e x a m in e d by th e su rg e o n , a n d i f th e w o u n d is h e a lth y th e ra n g e o f flexion is p ro g re s se d . II. ii. B ed Stage. (D a y 5 to day 10). T h e p a tie n t’s leg is e le v ate d in a T h o m a s s p lin t a n d P e a rs o n knee flexion piece. T h e p a tie n t’s leg is m a in ­ ta in e d in ex te n sio n fo r 45 m in u te s o f th e 60 m in u te s. D u rin g th is tim e iso m e tric q u a d ric e p s c o n tra c tio n s a re d o n e . T h is m ay be a id e d by p la c in g a ro lle d tow el u n d e r th e c alf to e n c o u ra g e the d e v e lo p m e n t o f v a stu s m ed ialis a n d fu ll ex te n sio n o f the k nee. T h e leg is a lso e xercised fo r 15 m in u te s o f th e h o u r in in c re a sin g flexion, using a system o f p u lle y s a n d h a n d c o n tro ls. In th is w ay flex io n of 7 0 ° to 8 0 ° can b e o b ta in e d . A t first th e flexion is passive; b u t as h is s tre n g th a n d c o n ­ fidence im p ro v e , th e m o v e m e n t is resisted. T h is is a v ery effective m e th o d o f g a in in g ra n g e a n d stre n g th , since th e p a tie n t is e n c o u ra g e d to ex erc ise by h im self. W h e n th e p a tie n t h a s g a in e d 70° flexion th e sp lin t is re m o v e d a n d th e n e x t few d a y s a re sp e n t stre n g th e n in g a n d in c re a s in g th e ra n g e o f m o v e m e n t o f the k nee jo in t. T h e p a tie n t p a rtic ip a te s in a n exercise p ro g ra m m e co n sistin g of: (a) K n e e p iv o ts d o n e o v e r th e side o f th e bed, u sin g P ro p rio c e p tiv e N e u ro m u s c u la r F a c ilita tio n te c h ­ n iq u es, su c h as h o ld -re la x , a n d c o n tra c t-re la x , to in c re a s e ra n g e a n d s tre n g th e n th e k n e e m uscles. T h e s e a re fo llo w e d by slo w re v ersa ls to c o n s o lid a te th e ra n g e g a in e d . T h e s e te c h n iq u e s m a y be fa c ili­ ta te d by th e u se o f ice p a ck s. (b) P ro g re ss iv e re sista n c e ex erc ises to in cre ase th e s tre n g th o f th e q u a d ric e p s . (c) A u to -re s iste d k n e e flex io n a n d e x te n sio n e xercises. (d) P ro n e lying (fee t dorsiflex e d ), k n e e e x te n sio n . (e) G e n e ra l s tre n g th e n in g e xercises fo r th e hip. R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) 8 P H Y S I O T H E R A P Y JUNE, 1975 T h e ra n g e o f flexion sh o u ld n e v e r be g a in e d a t th e e x p e n s e o f e x te n sio n a n d th e re fo re tim e is s p e n t in e m ­ p h a siz in g final k n e e e x te n sio n a n d a v o id in g a k n e e lag. T h is m a y b e a ch iev e d by p la c in g a k n e e b lo c k o r ro lle d to w e l u n d e r th e th ig h a n d e x te n d in g the k n e e in in n e r ra n g e . A s th e p a tie n t’s s tre n g th im p ro v e s, r e s is ta n c e is a d d e d a c c o rd in g ly a n d r h y th m ic a l s ta b iliz a tio n s m a y be u sed to e s ta b lish a sta b le knee. II I . A M B U L A T O R Y S T A G E S (day 10). T h e p a tie n t is a llo w e d u p p a r tia l w e ig h t-b e a rin g , th e w a lk in g a id s v a ry in g a c c o rd in g to th e p a tie n t’s d is ­ a b ilitie s. A s m a n y o f the p a tie n ts w e re e ith e r b e d ­ rid d e n o r se v e re ly h a n d ic a p p e d p r io r to the o p e ra tio n , th is sta g e is p ro g re s se d slow ly. T h e first d a y is s p e n t re g a in in g b a la n c e . T h e p a tie n t is th e n a llo w e d to w a lk k e ep in g th e k n e e in e x te n sio n , to g a in c onfidence. T h is is p ro g re s se d to w e ig h t tr a n s ­ fe re n c e , e m p h a siz in g a flexed k n e e d u rin g ‘p u s h off’, f o llo w e d by a n e x te n d e d knee in the sta n c e p h a se . T im e is sp e n t lo c k in g a n d u n lo c k in g th e k n e e a g a in s t re s is ta n c e w h e n sta n d in g . B e fo re d isc h arg e , th e p a tie n t is ta u g h t to c lim b sta irs a n d e n c o u ra g e d t o be as in d e p e n d e n t as possible. D u r in g this sta g e i t is im p o r ta n t n o t to lose the ra n g e o f flex io n g a in e d a n d to c o n tin u e to s tre n g th e n th e k n e e. P o o l th e ra p y is a u s e fu l m o d a lity to a c h ie v e this. T h e sw im m in g e x ercises in c lu d e d a re , specific P ro p rio c e p tiv e N e u r o m u s u la r F a c ilita tio n te c h n iq u e s, m o b iliz in g e x ­ ercises a n d g a it re -e d u c a tio n . E x erc ises in c lu d e d in th e p a ti e n t ’s h o m e p ro g ra m m e a re re c ip ro c a l p u lle y s p rin g e xercises, lu n g in g , deep k n e e b e n d s, s te p p in g u p a n d d o w n a b lo c k , a n d a u t o ­ re s is te d exercises. T h e p a tie n t is d isc h a rg e d w ith a sta b le , p a in fre e k nee, p a r tia l o r f u l l w e ig h t-b e a rin g . T h e ra n g e o f flex io n g a in e d is 90° in a g e o m e d ic o r 120° in a p o ly c e n tric p ro th e s is . S U M M A R Y : P h y s io th e ra p y p la y s a n im p o r ta n t r o le in th e p o s t­ o p e ra tiv e m a n a g e m e n t o f g e o m e d ic a n d p o ly c e n tric knee p ro th e s e s . T h e tre a tm e n t p ro g ra m m e can be d iv id e d in to v a rio u s sta g es, viz.: (1) P re-operative M anagem en t. T h is in c lu d e s a n a s ­ se ssm e n t of th e p a tie n t a n d a n e x p la n a tio n to the p a tie n t of th e tre a tm e n t p ro c e d u re . (2) P ost-op erative M anagem en t. T h is c a n be c o n sid e re d as a n im m e d ia te p o s t-o p e ra tiv e sta g e (d a y 1 to d a y 5) d u rin g w h ic h tim e th e p a tie n t d o e s iso m e tric q u a d ric e p s c o n tra c tio n s a n d sh o u ld g a in 2 0 ° flexion; a n d a B ed S ta g e (d ay 5 to d a y 10) d u rin g w hich tim e the ra n g e of flexion is in c re a s e d a n d th e k nee m u sc le s a re s tre n g th e n e d . (3) A m b u latory Stage (d a y 10). T h e p a tie n t is u su a lly p a r tia l w e ig h t-b e a rin g a t first a n d is p ro g re s se d to fu ll w e ig h t-b e a rin g . T h e p a tie n t is u su a lly d isc h a rg e d b e tw ee n tw o to th re e w eek s w ith a s ta b le b u t f u n c tio n a l k n e e , and a d v ised to fo llo w a h o m e p ro g ra m m e o f exercises. O P S O M M IN G : P h y s io te ra p ie is h o e g e n a a m d b e la n g rik en essensieel m e t d ie n a -o p e ra tie w e b e h a n d e lin g v a n g e o m e d iese en p o lie s e n trie s e p ro te se s. D ie b e h a n d e lin g w o rd in v e rsk ille n d e sta d iu m s ver- d eel: (1) V o o r-o p e ra tie w e b e h a n d e lin g . D ie g e este lik e en fisiese to e s ta n d v a n die p a sie n t w o rd in aggeneem en d ie p ro s e d u re v a n a lle b e h a n d e lin g w o rd aan d ie p a s ie n t v e rd u id e lik . (2 ) N a -o p e ra tie w e b e h a n d e lin g . D ie o n m id d e lik e o p e ra tie w e b e h a n d e lin g b e gin v a n a f die e erste d S ^ j e n d u u r to t op die 5de dag, w a a r die p a s ie n t iso- m etriese q u a d ris e p k o n tra k s ie o e fe n in g d o e n to td a t h y ’n fleksie p o sisie v a n 20° k a n b e h a a l. D a a r n a k o m die b e d s ta d iu m v a n a f die 5de d a g to t o p die lOde d a g w a a rb y die p a s ie n t sy fleksie p o sisie ver- m e e rd e r en so d o e n d e die knie sp ie re v e rste rk . (3) D ie o n tw ik k e lin g s ta d iu m b e gin n a die lOde dag. D ie p a s ie n t w o rd e ers n e t m e t g e d e e lte lik e gewig m e t k r u k k e b e h a n d e l en m e t b e v o rd e rin g v o ile ge­ wig op g e -o p e re e rd e lig g a m sd e el. D ie p a s ie n t w ord g e w o o n lik v a n a f tw ee to t d rie w eke n a -o p e ra tie f o n ts la a n m et ’n stew ige, m a a r n o r m a a l fu n k sio - n e re n d e k n ie p lu s ’n p ro g r a m v a n o e fen in g e w a t tuis g e d o e n m o e t w o rd . R E F E R E N C E S : i. R a d in (E ric L .), A p ril (1973): ‘B io m e c h a n ic s of K n e e J o in ts : Its Im p lic a tio n s in th e D esign o f R e ­ p la c e m e n ts .’ O rth . C lin , o f N o r th A m e ric a . Vol. 4 : 2, p p . 539. ii. W ild e A la n H ., A p ril (1973): ‘G e o m e tric K n e e R e ­ p la c e m e n t A rth o p la s ty : In d ic a tio n s f o r O p e ra tio n a n d P re lim in a ry E x p e rie n c e ’. O rth . C lin , of' N o rth A m e ric a . V ol. 4 : 2, p p . 547. iii. R ile y L ee H ., A p ril (1973): ‘G e o m e tric T o ta l K n e e R e p la c e m e n t: O p e ra tiv e C o n s id e ra tio n s .’ V o l. 4 : 7 " p p . 561. t A rtic le re c e iv e d D e c e m b e r, 1974. O B IT U A R Y J A N N I E K O E H O R S T It is w ith d e ep re g re t t h a t w e w rite o f th e d e a th d u rin g A p ril o f J a n n ie K o e h o r s t. H e w as a lm o s t c o m ­ p le te ly b lin d e d d u rin g th e W e s te rn D e s e rt C a m p a ig n d u rin g th e la s t W o rld W a r. H e t r a in e d a t St. D u n s ta n ’s a n d th e n set u p p ra c tic e in B lo e m fo n te in , w h e re he w o rk e d fo r m a n y y e a rs. H e w as h e ld in g re a t re g a rd a n d a ffe c tio n by a ll w h o k n e w h im . H e re tire d to C a p e T o w n to p u rs u e his f a v o u rite s p o r t o f d e ep sea sailing. T h is h e d id w ith c h a ra c te ris tic c o u ra g e th a t c o m m a n d e d th e re sp e c t o f h is fe llo w -y a e h ts m e n . O u r d e e p e st s y m ­ p a th y goes o u t to his w ife a n d fa m ily . P . J. K IL B E Y . R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. )