João N eves C am argo Júnior, A nam arli N ucci
S aphenous nerve entrapm ent m anifested
as proxim al cruralgia
General Hospital of the Medicai Science Faculty,
State University of Campinas, UNICAMP - Campinas, Brazil
A 1 6 y e a r o ld b o y h a d c o n tin u o u s p a in in th e rig h t te s tis , g ro in , a n d th e m e d ia i a s p e c t o f th e th ig h a n d k n e e fo r 1 6 m o n th s . T h e o n s e t o f s y m p to m s w a s a c u te a n d p a in d is trib u tio n in c lu d e d a re tro g ra d e a re a in re la tio n to th e e n tra p m e n t s ite . T in e l's s ig n w a s th e c lu e fo r d ia g n o s is . D ia g n o s is w a s c o n firm e d a t o p e ra tio n a n d d iv is io n o f th e a p o n e u ro s is o f H u n te r's c a n a l re lie v e d th e s y m p to m s fo r th re e d a y s . A s e c o n d s u rg ic a l e x p lo ra tio n , p ro x im a l to th e fo rm e r o n e , w a s p e rfo rm e d a fte r fiv e m o n th s . T h e rig h t fe m o ra l n e rv e w a s fo u n d n o rm a l. T h is n e w o p e ra tio n w a s th e ra p e u tic a lly in e ffe c tiv e . C a u s e s o f p a in d is trib u tio n a n d re la p s e d p a in a re d is c u s s e d . T h e re la p s e w a s a ttrib u te d to m y o fa s c ia l p a in s y n d ro m e . T h is d ia g n o s is s h o u ld b e c o n s id e re d in d e p e n d e n tly o f th e c o rre c t tre a tm e n t o f th e p rim a ry le s io n .
U N IT E R M S : S a p h e n o u s e n tra p m e n t n e u ro p a th y . S u rg ic a l s a p h e n o u s n e u ro ly s is . M y o fa s c ia l p a in s y n d ro m e . T rig g e r p o in ts .
IN T R O D U C T IO N
C
p u b lish e da se s o f sa p h e n o u sb e c a u se o f th e ir ra rity , d iffic u lt d ia g n o sisn e rv e e n tra p m e n t h a v e b e e n a n d v a rie ty o f sy m p to m s. T h e y m a y sim u la te v a sc u la rd iso rd e r, lum bar ra d ic u lo p a th y3 a n d k n e e jo in t le sio n4,5 ,6 . T h e
c a se w h ic h fo llo w s ra ise d d o u b ts a n d ta u g h t le sso n s th e a u th o rs
w o u ld lik e to sh a re w ith th e re a d e rs.
C A S E R E P O R T
A 1 6 y e a r o ld b o y w a s first se e n a t U N IC A M P a s a n
o u tp a tie n t in Ja n u a ry 1 9 8 8 . H e c o m p la in e d o f h a v in g h a d
p a in in th e rig h t le g fo r 8 m o n th s. Its o n se t w a s a b ru p t d u rin g
A d re ss fo r co rre sp o n d e n ce :
João N eves C am argo Jr.
R ua B arros M onteiro, 1 3 4 , Jd. G uanabara C am pinas/S P - B rasil - C E P 13073-240
a b o u t o f c o u g h in g . T h e p a in w a s la n c in a tin g a n d b u m in g in
th e rig h t te stis a n d g ro in , ra d ia tin g to th e m e d ia I a sp e c t o f
th e rig h t th ig h a n d k n e e . T h is p a in w a s c o n tin u o u s,
e x a c e rb a te d b y a n y m o v e m e n t o f th e rig h t lo w e r lim b o A fa ll
fro m a h o rse 3 m o n th s b e fo re th e b e g in n in g o f sy m p to m s
w a s re p o rte d . T h e p a tie n t w a lk e d w ith c ru tc h e s, ju st to u c h in g
th e rig h t fo re fo o t o n th e flo o r, k e e p in g th e a n ld e jo in t in
e q u in u s p o sitio n , th e k n e e jo in t in lig h t fle x io n a n d th e h ip
jo in t a d d u c te d , fle x e d a n d e x te m a lIy ro ta te d . T h e lo w e r b a c k
re g io n a n d rig h t a d d u c to r m u sc le s w e re p a in fu l w h e n
p a I p a te d . A su p e rfic ia l se n so ry d e fic it w a s n o te d , e x te n d in g
fro m th e rig h t g ro in th ro u g h th e m e d ia i sid e o f th e th ig h d o w n
to th e tib ia l m a le o lu s. U rin a ly sis, ro u tin e b lo o d a n a ly sis,
c e re b ro sp in a l flu id e x a m in a tio n , a b d o m in o -p e lv ic
u ltra so n o g ra p h y , c o n v e n tio n a l ra d io g ra p h y fo r sp in e , p e lv is
a n d k n e e , sk e le to n sc in tig ra p h y , C T o f sp in e a n d p e lv is a n d
e le c tro m y o g ra p h y d id n o t c o n trib u te to th e d ia g n o sis. T h e
m e a su re m e n t o f sa p h e n o u s c o n d u c tio n v e lo c ity th is c a se
w o u ld re q u ire w a s b e y o n d o u r re a c h a t th a t tim e . In Ju n e
1 9 8 8 a T in e l's sig n w a s d e te c te d o n th e m e d ia I a sp e c t o fth e
d ista I th ird o fth e rig h t th ig h a n d a p o sitiv e in v e rse L a se g u e 's
sig n w a s fo u n d .
In A u g u st 1 9 8 8 th e rig h t sa p h e n o u s n e rv e w a s su rg ic a lly
e x p lo re d a n d n e u ro ly sis p e rfo rm e d (fig .1 ). T h e o n ly
C A M A R G O J r., J .N . &N U C C I, A . - S a p h e n o u s n e rv e e n tra p m e n t m a n ife s te d a s p ro x im a l c ru ra lg ia
1554
F ig u re 1 - S a p h e n o u s n e rv e (S .N .) a fte r lo n g itu d in a l d iv is io n o f th e a p o n e u ro tic w a ll o f H u n te r's c a n a l. S .N . is h e ld w ith a P e n ro s e d ra in . R e tra c to rs a re p u llin g th e s a rto riu s m u s c le . A p a d p ro te c ts th e v a s tu s m e d ia lis m u s c le .
constringency found was at the point where the nerve pierced
the Hunter's canal aponeurosis. In the post-operative period
the patient, relieved from pain, could walk and even climb
stairs. From the 4th post-operative day onwards, symptoms
recurred, although less severely. In September 1988 the
patient was back on crutches. Gentle stretching of the affected
muscles, and Amitriptyline and Phenylbutazone were
ineffective. In January 1989 pain was mainly felt in the right
testis and groin. A second surgical exploration was then
perfomed, from the upper end of the former one up to the
inguinal ligamento The femoral nerve was normal.
Carbamazepine, Paracetamol and "Cronassial" proved
useless. In 1990 the patient could walk without crutches again.
Since 1992 ~e has been asymptomatic.
D IS C U S S IO N
Nerve lesion was found about 10cm above the right
knee joint. Could pain in the right testis and groin, present
from the very onset of symptoms, be explained by an
overflow in the internuncial pool caused by impulses from
saphenous nerve stimulation, giving rise to sensations which
originated in more proximal portions of this nerve and its
anastomosis?4.
Three days without pain, relief of pain with rest and
lack of response to Carbamazepine mIe out de-afferentation
as a cause of relapsed pain7• Sixteen months elapsed between
the onset of symptoms and neurolysis. During that period
of time the right lower limb was kept in a non-physiological
position, which must have caused a myofascial pain
syndrome. The recurrence of pain almost certainly
developed from trigger points I that should have been
identified and inactivated at that time. The second operation
was clearly unnecessary. Psychiatric treatment, wisely
refused by the patient, would also have been redundante
RESUMO
U m ra p a z d e 1 6 a n o s a p re s e n ta v a d o r c o n tín u a n o te s tíc u lo , re g iã o in g u in a l, fa c e m e d ia i d a c o x a e jo e lh o d ire ito s h á 1 6 m e s e s . O c o m e ç o d o q u a d ro fo i re p e n tin o e a m a io r p a rte d o s s in to m a s e ra p ro x im a l à le s ã o . O d ia g n ó s tic o fo i fe ito a o s e d e te c ta r o s in a l d e T in e l e c o n firm a d o n a c iru rg ia . A a b e rtu ra lo n g itu d in a l d o c a n a l d e H u n te r, lib e ra n d o o n e rv o n a s u a e m e rg ê n c ia d o m e s m o p ro v o c o u a c e s s a ç ã o d a d o r p o r trê s d ia s . C in c o m e s e s d e p o is d a p rim e ira , p ro c e d e u -s e a u m a n o v a e x p lo ra ç ã o c irú rg ic a , p ro x im a l àa n te rio r, q u e re v e lo u o n e rv o fe m o ra l d ire ito n o rm a l e n ã o te v e q u a lq u e r e fe ito te ra p ê u tic o . A s c a u s a s d a lo c a liz a ç ã o e d a re c id iv a d o s s in to m a s s ã o d is c u tid a s . O s a u to re s a trib u e m a re c id iv a d a d o ràs ín d ro m e d a d o r m io fa s c ia l, d ia g n ó s tic o a s e r le m b ra d o in d e p e n d e n te m e n te d o tra ta m e n to c o rre to d a le s ã o p rim á ria .
REFERENCES
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2. Mozes M, Quaknine G, Nathan H. Saphenous nerve
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3. Saal IA, Dillingham MF, Gamburd RS, Fanton GS. The
pseudoradicular syndrome. Spine 1988; 13: 926-930.
4. Kopell HP, Thompson WAL. Knee pain due to saphenous
nerve entrapment. New Eng 1 Med 1960; 263: 351-353.
5. Romanoff M E, Cory IR PC, Kalenak A, Keyser GC,
Marshall WK. Saphenous nerve entrapment at the adductor canal. Am 1 Sports Med 1989; 17: 478-481.
6. Worth RM, Kettelkamp DB, Defalque RI, Duane KU.
Saphenous nerve entrapment. A cause of mediaI knee pain. Am 1 Sports Med 1984; 12: 80-81.
7. Bouchez B, Amott G, Delandsheer E, Blond S, Guieu lD.
Neuropathie cru rale avec douleurs de déafferentation. Acta neurol belg 1985; 85: 269-276.
C A M A R G O J r., J .N . & N U C C I, A . - S a p h e n o u s n e rv e e n tra p m e n t
m a n ife s te d a s p ro x im a l c ru ra lg ia
