MORPHOLOGICAL
CHANGES
IN THE ARTICULAR
AFTER
MENISCECTOMY
AN
EXPERIMENTAL
STUDY
A. M. LurFi,
From
the
Department
of Anatomy,
IN
MONKEY
SUDAN
KHARTOUM,
Faculty
THE
CARTILAGE
of Medicine,
University
of Khartoum
The medial meniscus was resected from the right knees of twelve young grivet monkeys
that were killed at
of twenty-one
to 252 days after operation.
The knees operated
upon and the control knees were
investigated
radiologically
and histologically.
Degenerative
changes
occurred
in the medial femoral
and
tibial
condyles.
At first there was loss of cells from the superficial
layer of the articular
cartilage,
with a
marked
decrease
in the acid mucopolysaccharide
content
of the matrix.
The chondrocytes
in the deeper
layer
of the non-calcified
zone proliferated
to form clones before finally
degenerating.
The acellular
cartilage
showed splitting,
and with progress
of the degenerative
process
there was thinning
and erosion of the cartilage.
Eventually
there was complete
loss of articular
cartilage
with thickening
and exposure
of the subchondral
bone.
These degenerative
changes were confined
to a small area of the articular
cartilage
and had occurred
despite
regeneration
of the meniscus.
The rest of the cartilage
looked normal.
It is concluded
that articular
cartilage
deprived
of the protection
of a meniscus may undergo arthritic
changes.
intervals
Although
various
the
it is generally
procedure
1942
of menisci,
has
also
the
of
knee
(MacConaill
1932,
are
credited
with
formed
the
1950;
King
1936),
much
narrower
is a harmless
Walmsley
1937;
ossific
centre
believed
that meniscectomy
(Gibson
1931 ; Bruce
and
McMurray
tion
menisci
functions
been
; Evans
1963).
known
noted
Furthermore,
to occur
in man
on many
part
band
(Fig.
of its
of calcified
thickness
(Fig.
cartilage
adjacent
1) and
a
to the
2).
regenera-
experimental
in
greater
animals,
occasions
(Golden-
berg
1935 ; Smillie
1944, 1967 ; Doyle,
Eisenberg
and Orth
Kopta
and Blosser
1969).
Reported
histological
studies
of the effect
of meniscectomy
on the articular
1966;
cartilage
and
bone
are
few
and
inadequate.
of this experiment
was to throw
morphological
changes
in articular
of the
corresponding
young
further
cartilage
4
AND
grivet
At
cified
METHODS
monkeys
(Cercopithecus
the
time
of killing,
then processed
were fixed
.
aethiops
both
knees
were
radiodecal-
formic acid, double embedded
at 8 to 10 t in the sagittal
or coronal
was
stained
with
eosin, Weigert’s
Van Gieson,
and examined
under the light
Ehrlich’s
safranin
0
microscope.
or
.;J
articular
cartilage
in
histologically
like
that
The
was
divisible
cartilage
Dr A. M. Lutfi,
VOL.
57-B,
Head,
the
.4
FIG.
Normal
of other
into
Department
No. 4, NOVEMBER
1975
articular
grivet
shows
drocytes.
blue,
1
cartilage
in a young
monkey.
The superficial
layer
a high density offlattened
chon-
(Haematoxylin
and
eosin,
x320.)
The
grivet
‘p
..‘
OBSERVATIONS
The
4
.
and
toluidine
p
,
and serially
plane.
Every
haematoxylin
S
1
as a
were
after
for histological
examination.
in 10 per cent formol
saline,
in 5 per cent
sectioned
tenth
section
.4 -
I
meniscus
was then removed.
The left knee served
The animals
stayed
loose
in their
cages
and
at intervals
between
twenty-one
and
252 days
operation.
. 4rt #
:
meniscus
was separated
from the capsule until the attachment
of the posterior
horn to the tibia was seen and divided.
The
graphed
and
Specimens
.,..
light
on the
after removal
aethiops)
were used.
The medial
meniscus
in the right knee of
each monkey
was exposed
through
a parapatellar
incision.
The
anterior
horn
of the meniscus
was detached
from
the tibia.
While
steady
traction
was applied
to the detached
horn
the
whole
control.
killed
,
object
meniscus.
MATERIAL
Twelve
The
monkey
mammals
appears
including
an uncalcified
of Anatomy,
zone
Faculty
man.
which
superficial
tilage consisted
cells disposed
surface
of Medicine,
(Fig.
University
layer
of the
normal
uncalcified
car-
ofthree
to five concentric
rows of flattened
with their long axes parallel
to the articular
1).
The
cells
of Khartoum,
in this
layer
were
lying
P.O. Box 102, Khartoum,
almost
Sudan.
525
526
A.
end-to-end
chondrocytes
larly
and
were
became
arranged.
shared
the
closely
oval
Groups
same
packed.
Traced
or rounded,
and
of
lacuna
and
two
to
were
M.
LUTFI
calcified
matrix.
The calcified
the normal
hyaline
cartilage
inwards,
the
were irregu-
four
a network
(Fig. 2).
chondrocytes
surrounded
by
a more
of arches
of cancellous
bone on the other
The osteo-chondral
junction
was undulating
p.,
,
.
I
..,.
S
I
.
#{149}#{149}S
.4
S
S
*1
#{149}jl
,‘
side
and
4..
‘t#{149}.
P4
..
gradually
into
and rested
on
.,,
0
.‘
area faded
on one side
Is
.
S
.
..‘
I,
#{149}‘2
#{149}
S..
‘
#{149} h4
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4
‘4
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#{182},
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:
‘.
I
#{149}
SI
2
osteochondraljunction
.i
t
b
‘
FIG. 4
Three
weeks after meniscectomy
corresponding
femoral
and tibial
dyles are closely apposed.
FIG.
The normal
cartilage
in a young
grivet
Van Gieson,
ofthe
monkey.
270.)
articular
(Weigert’s
the
con-
FIG.
3
weeks after meniscectomy
there is loss of
chondrocytes
from
the superficial
layer of the
articular
cartilage
and
active
proliferation
of
deeply
situated
cartilage
cells.
(Alcian
blue
Weigert’s
Van Gieson,
>< 320.)
Three
p.
*
a,a(,e+:!dS
i;
I
,..
#{149}%
:‘#{190};’
,
L*
-
..,
;
FIG. 5
Twelve weeks after meniscectomy
the articular
cartilage
is partly
eroded
and the subchondral
bone much thickened.
Note the tide
mark between the calcified and non-calcified
regions of the cartilage.
(Haematoxylin
and eosin,
< 120.)
abundant
The matrix
safranin
the
intensity
matrix
ofthe
0,
than
was
uncalcified
toluidine,
of
seen in the superficial
zone stained
uniformly
alcian blue or haematoxylin,
the
staining
diminished
the articular
surface.
cytes
enlarged
and
Nearer
were
the ossific
ultimately
slightly
With progress
of the degenerative
process
there is total loss of the
articular
cartilage
in places, with excessive
thickening
and lamellation of the subchondral
bone.
On either side of the exposed
bone
the tide mark separates
calcified
and non-calcified
layers of the
layer.
with
but
cartilage.
(Haematoxylin
the subchondral
bone
was interrupted
processes
penetrated
subchondral
which
were
surface.
towards
centre the chondrosurrounded
by
articular
a
Three
which
bone
mainly
weeks
THE
into
and eosin,
x 120.)
in places
the
by marrow
calcified
matrix.
The
itself was supported
by bony trabeculae
aligned
at right angles
to the articular
after
JOURNAL
meniscectomy
OF
BONE
there
AND
was
JOINT
a loss
SURGERY
of
MORPHOLOGICAL
the
chondrocytes
(Fig.
cartilage
width
and
was
cartilage
four
The
matrix
stained
with
blue.
layer
in the
superficial
This
therefore
acellular
layer
was
separated
from
THE
of the
ARTICULAR
articular
Elsewhere
the basophilia
(tide
of irregular
the cellular
of the uncalcified
greatly
diminished.
intensity
of the
regions
also
was
less
superficial
layer
than
only
the
were
Followed
Apart
became
from
small
the
these
thin
cellular,
but
a continuous
sian
lamellar
canals.
the calcified
plate
Away
with
from
and uncalcified
developed
into
bone
profiles
the
centre
of many
of
the
Haver-
lesion
the
(Fig.
These
the
and
were
still,
in the
changes
tissue
grew
showed
femoral
cells
peripherally
degenerative
of fibrous
Radiographs
medial
the
diminished
between
The subchondral
of cartilage.
between
calcified
normal.
More
early
shreds
capsule.
between
appeared
527
MENISCECTOMY
a small
localised
area.
centre
of this area
the
rounded
rather
than
fusiform.
the cartilage
looked
normal.
cartilage
mark)
layers
AFTER
cartilage
The contrast
uncalcified
and
pronounced
limited
to
outwards
from
changes
CARTILAGE
in the immediate
vicinity
of these
clones
haematoxylin,
toluidine,
safranin
or alcian
matrix
was
the staining
from
IN
by a wavy
line.
The rest of the uncalcified
exhibited
marked
proliferative
activity
: clones
to sixteen
cells were
seen in the same
lacuna.
cartilage
of
3).
CHANGES
that
tibial
inwards
the
space
condyles
8
FIG.
The regenerated
meniscus ultimately occupies the position of the
resected medial meniscus so that
the narrowing
of the space between
the femoral and tibial condyles is no longer seen.
I
had
4).
gradually
regained
its thickness
The
tide
mark
disappeared
bone became
cancellous.
cartilage
cellularity.
chondral
In the
loss
more
of the
total
subchondral
bone.
compact
-t
advanced
and
lesions
thickness
The
its
latter
lamellar
side of this denuded
cartilage
was
delineated
mark.
cellularity
chondrocytes
the
was
exposing
much
even
area
from
6) there
thus
became
character
On either
the tide
reduced
(Fig.
of cartilage,
and
normal
and the sub-
thicker
more
and
obvious.
a thin layer
calcified
a
the
of hyaline
cartilage
by
Again
the uncalcified
cartilage
showed
in its superficial
layer and clusters
of
were
found
in its deeper
parts.
The
cartilage
lost its metachromasia.
Further
outwards
the articular
cartilage
and subchondral
bone
were
of normal
appearance
and there was no tide mark.
While
these degenerative
changes
were progressing,
also
the fibrous
tissue
from the capsule
disc (Fig. 7).
tissue
without
.
-
strands
which were seen growing
at earlier
stages,
matured
into
This
any
experiment
the
which
insinuated
-
regenerated
cartilage
disc
cells.
disc grew
into
itself between
consisted
By the
(Fig.
regenerated
tissue.
the
meniscus
A much
tibial
narrower
condyle.
consists
band
of
is seen
(Haematoxylin
and
to
Localised
eosin,
x 120.)
At twelve
degenerative
weeks
lesion
ficial layer also
several
places.
form
VOL.
multicellular
57-B,
the cartilage
was
partly
eroded
at
the
(Fig.
appeared
devoid
of cells
The deeper
chondrocytes
clusters.
No. 4, NOVEMBER
A densely
1975
centre
5).
of the
Its super-
and was split
proliferated
stained
wavy
narrowhardly
the
medial
DISCUSSION
fibrous
closer
was
8).
Fio. 7
The
of fibrous
end of the
a flat circular
cushion
the medial
femoral
and
tibial condyles,
with the effect that the joint-space
ing observed
in the early post-operative
stages
discernible
inwards
a definite
in
to
line
degenerative
femoral
and
excision
of
changes
occurred
tibial
condyles
of the
the
medial
meniscus.
on
grivet
The
monkey
after
degeneration
appeared
to occur
by sequential
changes
: at first there
was loss ofcells
from the superficial
layer ofthe
uncalcified
cartilage
and concomitant
proliferation
of cells in the
deeper
with
layer.
loss
These
of matrix
cellular
basophilia.
changes
were
As the
also
lesion
associated
progressed
528
A.
there
was
a gradual
disintegration
of the
M.
non-calcified
subchondral
bone.
The
were similar
to those
observed
in osteoarthritis
and in animals
by several
workers
(Collins
and
cartilage
and
changes
in man
McElligott
thickening
1960;
the
of
Meachim
and
Collins
1963 ; Mankin
and Lippiello
1969).
King (1936) also found
degenerative
changes
of the medial
tibial
and femoral
condyles
after
excision
of the medial
meniscus
in the dog’s
knee.
In
man
radiographic
changes
including
narrowing
of
joint space and flattening
of the articular
cartilage
observed
at varying intervals
up to twenty-one
years
the
were
after
LUTFI
fication
(the tide mark)
appeared
between
the calcified
and non-calcified
layers of the articular
cartilage
and the
chondral
bone developed
into a continuous
lamellar
plate.
Due to the formation
of these impermeable
barriers
diffusion
of nutrients
from
the blood
vessels
of the
secondary
ossific centre would be severely hampered,
thus
enhancing
the degenerative
process even further.
Brower
and Hsu (1969) observed
the presence
of the tide mark
in articular
cartilage
of the mature
skeleton
only, and
suggested
that adult articular
cartilage
derivedits
nutrients
solely
from
the
synovial
fluid.
arthritic
lesions in areas ofcartilage
subjected
to excessive
load bearing
(Thompson
and Bassett
1970; Sood 1971).
The prolonged
contact
between
the articular
surfaces
would interfere
with the diffusion
of nutrients
from the
The present
findings
emphasise
the role of the semilunar menisci in protecting
the articular
hyaline cartilage.
Furthermore,
they illustrate
clearly the role ofthe articular
cartilage
in redistributing
the compressional
forces impinging
on the articular
surfaces,
because,
where
the
articular
cartilage
was markedly
thinned
or lost, the
subchondral
bone was greatly thickened
to withstand
the
more direct
compressional
stress.
It is highly
probable
that, with time, the regenerated
disc would acquire
the
structural
and functional
properties
of its predecessor.
However,
free use of the limb shortly after meniscectomy
-that
is, before
the new disc is well developed-may
cause
osteoarthritic
changes
in the articular
cartilage.
It is therefore
appropriate
to try and establish
in man
the period oftime
needed for a regenerating
disc to mature
synovial
fluid
and
progress
of the
meniscectomy
(Huckell
1965).
On
the
other
hand
Bruce
and Walmsley
(1937) were unable
to confirm
the occurrence of histological
changes
after meniscectomy.
It was noted in this experiment
that for a few weeks
after removal
of the meniscus
the femoral
and tibial
articular
surfaces
came into closer
proximity.
As the
animals
able
were
allowed
to assume
that
free
there
use
of their
was
increased
limbs
it is reason-
friction
between
the opposing
articular
surfaces which ultimately
produced
the degenerative
changes
in the articular
cartilage
as
described
above.
am grateful
Other
(Salter
workers
and
degenerative
Field
lesion,
also
1960).
a line
reported
Moreover,
of heavy
osteo-
with
calci-
to
carry
osteoarthritis
out
its
specffic
functions
if
the
risk
of
is to be avoided.
Research
of the University
of Khartoum
for a grant from
University
of Beirut for a Commonwealth
Grant
three months in the Department
of Human
Morphology,
where I had access to all the references
I needed.
I wish to express
my thanks to my colleagues
Dr Adil Afifi and Dr Mohamed
Ibrahim for the photographic
work and to Mr Abdel Rabman
Mohamed
Osman for technical assistance.
I
to the Faculty
their research
funds towards
which enabled me to spend
of Medicine
Research
the cost of this work.
Board and to the
I am also indebted
Committee
to the American
REFERENCES
Brower,
and Hsu, W.-Y. (1969) Normal articular cartilage.
Clinical Orthopaedics
and Related
Research,
64, 9-17.
and Walmsley,
R. (1937) Replacement
of the semilunar
cartilages
of the knee after operative
excision.
British Journal of Surgery,
25, 17-28.
Collins, D. H., and McEffigott,
T. F. (1960) Sulphate
(35SO4) uptake by chondrocytes
in relation to histological
changes in osteo-arthritic
human
articular
cartilage.
Annals ofthe
Rheumatic
Diseases,
19, 318-330.
Doyle, J. R., EiSenberg,
J. H., and Orth, M. W. (1966)
Regeneration
of knee menisci: a preliminary
report.
Journal ofTrauma,
6, 50-55.
Evans,
F. G. (1963)
Stress and strain of posture,
expressed
in the construction
of man’s weight-bearing
skeletal structures.
Clinical
Orthopaedics,
25, 42-54.
Gibson, A. (1931) Regeneration
of internal
semilunar
cartilage
after operation.
British Journal ofSu,rgery,
19, 302-305.
Goldenberg,
R. R. (1935) Refracture
of regenerated
internal
semilunar
cartilage.
Journal ofBone
andJoint
Surgery,
17, 1054-1057.
Huckell,
J. R. (1965)
Is meniscectomy
a benign procedure?
Canadian
Journal
ofSurgery,
8, 254-255.
King, D. (1936) The function
of semilunar
cartilages.
Journal ofBone
andJoint
Surgery,
18, 1069-1076.
Kopta,
J. A., and Blosser,
J. A. (1969)
Elasticity
of articular
cartilage.
Effects of intra-articular
steroid administration
and medial
meniscectomy.
Clinical Orthopaedics
and Related
Research,
64, 21-32.
MacConaill,
M. A. (1932) The function
of intra-articular
fibrocartilages,
with special reference to the knee and inferior radio-ulnar
joints.
Journal ofAnatomy,
66, 210-227.
MacConaill,
M. A. (1950) The movements
ofthe bones andjoints.
3. The synovial fluid and its assistants.
JournalofBone
andJoint
Surgery,
32-B, 244-252.
McMurray,
T, P. (1942)
The semilunar
cartilages.
British Journal ofSurgery,
29, 407-414.
Mankin,
H. J., and Lippiello,
L. (1969)
The turnover
ofadult
rabbit articular
cartilage.
JournalofBone
andJoint Surgery, 51-A, 1591-1600.
Meachim,
G., and Collins,
D. H. (1962) Cell counts of normal
and osteo-arthritic
articular
cartilage
in relation
to the uptake
of sulphate
(“SO4)
in vitro.
Annals ofthe Rheumatic
Diseases,
21, 45-50.
Salter, R. B., and Field, P. (1960) The effects of continuous
compression
on living articular cartilage.
Journal
ofBone
andJoint
Surgery,
42-A, 31-49.
Smillie,
I. S. (1955)
Observations
on regeneration
of semilunar cartilages
in man. British Journal ofSurgery,
31, 398-401.
Smillie,
L S. (1967) The current
pattern
of internal
derangements
of the knee joint relative
to the menisci.
Clinical Orthopaedics
and
Related
Research,
51, 117-122.
Sood, S. C. (1971) A study of the effects of experimental
immobilisation
on rabbit articular
cartilage.
Journal ofAnatomy,
108, 497-507.
Thompson, R. C., Jun., and Bassett, C. A. L. (1970) Histological
observations
on experimentally
induced
degeneration
ofarticular
cartilage.
Journal ofBone
andJoint
Surgery,
52-A, 435-443.
Bruce,
T. D.,
J.,
THE
JOURNAL
OF
BONE
AND
JOINT
SURGERY