SKULL, FRACTURE OF
TYPES OF SKIN GRAFT
The two main types of skin graft are split-thickness (in which less than the full
thickness of skin is removed from the donor site) and full-thickness (in which a
deeper thickness is removed). There are advantages to each of these types.
Split-
thickness
Full-
thickness
Split-thickness graft
When large areas need to be covered,
such as after burns, split-thickness grafts
are used and the donor sites are left to
regenerate, which theydo in a few days.
Such sites can be repeatedly harvested.
Full-thickness graft
Full-thickness skin grafts are usually preferred
for the face because theymore closelymatch
the appearance of normal skin. However, donor
sites are limited and must be sutured (stitched).
HOW A FULL-THICKNESS GRAFT IS DONE
Most skin grafts are performed under general anaesthesia. Full-thickness
grafts can be obtained easily with a scalpel. Subcutaneous fat is avoided
and any bleeding at the recipient site prevented.
I
Skin for a full-thickness
graft is often taken from
behind the ear.
2
The graft must be
slightlylarger than the
area to be covered, to allow
for shrinkage.
3
Precise fitting and firm
pressure are needed
to ensure there isa
satisfactory “take”.
Instruments
Split-skin grafts are cut,
usually from the abdomen
or thigh, with an instrument
called a dermatome. If
necessary, the skin can be
expanded into a trellis-like
mesh on the donor site.
s k in tu m o u r
A g r o w t h d e v e l o p i n g o n o r i n t h e
s k in
t h a t m a y b e c a n c e r o u s ( s e e
s k in c a n c e r)
o r
n o n c a n c e r o u s .
K e ra to s e s
a n d
s q u a -
m o u s
p a p illo m a s
a r e c o m
m o n t y p e s o f
n o n c a n c e r o u s t u m
o u r ; o t h e r t y p e s i n c -
l u d e
s e b a c e o u s c y sts,
c u t a n e o u s
h o rn s ,
k e ra to a c a n th o m a s ,
a n d
h a e m a n g io m a s .
s k u ll
T h e b o n y s k e l e t o n o f t h e h e a d , w h i c h
p r o t e c t s
t h e
b r a i n ; h o u s e s
t h e
s p e c i a l
s e n s e
o r g a n s
( e y e s ,
e a r s ,
t o n g u e ,
a n d
n o s e ) ; p r o v i d e s p o i n t s o f a t t a c h m e n t f o r
f a c i a l ,
s c a l p ,
a n d
n e c k
m u s c l e s ;
a n d
f o r m s p a r t o f t h e r e s p i r a t o r y a n d d i g e s -
t i v e t r a c t s .
STRUCTURE
A l l t h e s k u l l b o n e s , e x c e p t t h e m a n d i b l e
( l o w e r j a w ) a r e f i x e d t o o n e a n o t h e r b y
i m m o v a b l e s u t u r e s ; t h e s k u l l b o n e s d o
n o t f u s e u n t i l a b o u t
1 8 m o n t h s o f a g e
( s e e
f o n ta n e lle ).
T h e c r a n i a l c a v i t y h o u s e s
t h e b r a i n ; o t h e r s k u l l s t r u c t u r e s i n c l u d e
t h e n a s a l c a v i t y a n d e y e o r b i t s .
S e v e r a l o f t h e s k u l l b o n e s , e s p e c i a l l y
t h o s e
a r o u n d
t h e
n a s a l
a r e a ,
c o n t a i n
s in u s e s
( a i r
s p a c e s ) .
I n
t h e
c r a n i u m ,
t h e r e a r e m a n y h o l e s f o r t h e p a s s a g e o f
n e r v e s a n d b l o o d v e s s e l s . T h e l a r g e s t o f
t h e h o l e s , c a l l e d t h e f o r a m e n m a g n u m ,
i s s i t u a t e d i n t h e o c c i p i t a l b o n e ( w h i c h
f o r m s p a r t o f t h e b a s e a n d b a c k o f t h e
c r a n i u m
) ; t h i s h o l e a l l o w s t h e
b ra in s te m
t o e n t e r t h e s p i n a l c a n a l , w h e r e i t c o n -
t i n u e s a s t h e s p i n a l c o r d .
T h e s k u l l r e s t s o n t h e a t l a s ( t h e f i r s t
c e r v i c a l v e r t e b r a ) , w h i c h i s a r i n g - s h a p e d
b o n e
t h a t
a r t i c u l a t e s w i t h
t h e
o c c i p i t a l
b o n e a n d p e r m i t s n o d d i n g m o v e m e n t o f
t h e h e a d . T u r n i n g t h e h e a d i s a f u n c t i o n
o f t h e j o i n t b e t w e e n t h e a t l a s a n d t h e
s e c o n d c e r v i c a l v e r t e b r a e , w h i c h i s c a l l e d
t h e
a x i s . T h e
o c c i p i t a l b o n e ,
a t l a s ,
a n d
a x i s a r e c o n n e c t e d t o g e t h e r b y n u m e r -
o u s s m a l l m u s c l e s .
DISORDERS
T h e s k u l l m a y b e a f f e c t e d b y a n y d i s o r -
d e r t h a t i n v o l v e s t h e s k e l e t o n , s u c h a s
P a g e t ’s d is e a s e ,
b u t t h e m o s t c o m m o n
d i s o r d e r i s i n j u r y . A b l o w t o t h e h e a d
m a y c a u s e a f r a c t u r e
( s e e
s k u ll, fra c tu re
o f
) , p o s s i b l y l e a d i n g t o b r a i n d a m a g e .
( S e e a l s o
h e a d in ju ry .)
s k u ll, fra c tu re o f
A b r e a k o c c u r r i n g
i n o n e o r m
o r e o f
t h e
s k u ll
b o n e s
a s
a
r e s u l t
o f a
h e a d
in ju ry .
I n m
o s t s k u l l f r a c t u r e s , t h e r e a r e
n o
c o m p l i c a t i o n s .
I n
a
s e v e r e
i n j u r y ,
h o w e v e r , t h e b r o k e n b o n e s m a y b e d i s -
p l a c e d . I f t h i s h a p p e n s , b o n e f r a g m e n t s
m a y r u p t u r e b l o o d v e s s e l s i n t h e
m e n -
in g e s
( t h e
m e m b r a n e s
c o v e r i n g
t h e
b r a i n )
o r ,
r a r e l y ,
t e a r
t h e
m e n i n g e s ,
r e s u l t i n g i n b l e e d i n g a n d , i n s o m e c a s e s ,
b r a i n d a m a g e .
A n
u n c o m p l i c a t e d
f r a c t u r e
o f
t h e
s k u l l u s u a l l y h e a l s b y i t s e l f . H o w e v e r , i f
t h e r e i s a n y d a m a g e t o b r a i n s t r u c t u r e s
n e u r o s u r g e r y i s o f t e n r e q u i r e d . ( S e e a l s o
d e p re s s e d s k u ll fra c tu re ; e x tra d u ra l h a e m o r-
rh a g e ; s u b a r a c h n o id h a e m o rrh a g e ; s u b -
d u ra l h a e m o r r h a g e ).
Skull fracture
In this X-ray image, a fracture of the back of the
skull is visible as a long, dark, horizontal line
across the orbit of the right eye (left on the image).
S
695
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