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We have talked about knee joint, and we said that the knee joint is a very
important joint, very complex, it has so many ligaments, Participation of so
many muscles that are around the knee and will enforce the knee.
The cruciate ligaments
Those cruciate ligaments which are located in the middle of the joint,
intracapsular but outside the synovial membrane. They are thick ligament that
maintain the anterior posterior mobility of the joint, and we have seen that one
of them (the anterior) prevents hyperflexion and the posterior prevents
hyperextension. They are named according to the attachment to the tibia, the
anterior cruciate ligament (ACL) is attached to the tibia anteriorly and the
posterior cruciate ligament (PCL) to the posterior ridge.
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The anterior comes superior to anterior tibial tuberosity and takes part of its
insertion from the anterior horn of the medial meniscus, then the posterior
one come from the lateral aspect of the tibia and takes part of its origin from
the posterior horn of the lateral meniscus. Therefore they are very important
and each one has its own function. Also the anterior crosses lateral to the
posterior one as well as the intercondylar region, so the anterior goes lateral
where the posterior goes medial.
The anterior prevents the anterior displacement of the tibia, the posterior
prevents the posterior displacement, and both of them are attached to the
intercondylar fossa and to the tibia as well, as well as to the menisci.
As you see in the image above, that the posterior one is wider and attached to
the posterior edge of the intercondylar crest, goes all the way medially and is
situated medial to the anterior one.
The medial and lateral collateral ligaments
The medial/tibial collateral ligament is wider than the lateral/fibular one, and
has more enforcement rather than the lateral one which goes to the head of the
fibula and is thinner and had a little enforcement on the popliteal ligament
together with the tendon of popliteus muscle.
Here is the medial:
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And here is the lateral:
Oblique popliteal ligament
The oblique popliteal ligament it is an expansion from the
semimembranosus tendon close to its insertion to the tibia and located
lateral to the medial collateral ligament and crosses anterior to the long head
of the biceps femoris.
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The anatomy of the menisci
The menisci are composed of many fibers that will sustain the pressure, such
as the type 3 collagen fibers together with the chondrocytes which is very
abundant. It has a thicker margin and a thinner one which gave it this
triangular shape.
You can see below the radial fibers in the medial aspect toward the inner
surface of the meniscus which goes all the way from side to side and are
located between the circumferential fibers, and these circumferential fibers
makes the outer surface and goes all around from the thicker (upper) margin
of the meniscus to the thinner one . You can also see the chondrocytes region
which mean that it’s a hyaline cartilage, a very strong hyaline cartilage. So
it’s not a cartilaginous joint, it’s only a hyaline cartilage structure.
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They are both intracapsular and intrasynovial, and the synovial membrane is
attached to the outer aspect above and below the menisci, so they are
considered both intracapsualar and intrasynovial according to the doctor
(because there always a debate in some books about the intracapsular and
extracapsular structures so consider what the doctor said). Now, fracture or
erosion of these menisci is very dangerous, they are highly vascularized, and
get their vascularization from the capsule to the lateral surface (I think its
better if he said “get their nourishment” rather than “vascularization” and you
will see why). Now, remember that the hyaline cartilages are avascular and
are nourished by the synovial fluid, but look at the picture!!! It’s vascularized,
isn’t it?!!!!! Confusing, right?!!! Here the debate occurs:
The debate says: these menisci could be either intracaspsular & intrasynovial,
or intracapsular and extrasynovial.
In the first case (intracapsular & intrasynovial), the vessels that nourish the
capsule will nourish the synovial fluid and the menisci will get their
nourishment from the synovial fluid by diffusion (so intracapsular &
intrasynovial).
In case of being extrasynovial, that means the vessels will directly penetrate
the capsule and vascularize the menisci, meaning that they will get their
vascularization from the capsule.
So, in conclusion the doctor agrees (and we should consider it true) with the
first case (intracapsular & intrasynovial, receiving their nutrient from the
synovial fluid … etc) which means that the picture is wrong. I know it may be
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a little confusing, I tried to make it as simple as I can, but you can refer to the
record (min 20-24:27) along with the 52nd slide, if you care. (Believe me I
explained everything, so forget about the record now.)
Continue…
Function of the menisci
• Shock absorption
• Redistributes forces of the movement
• Spread synovial fluid
• Minimal effect on stability
• On rotation menisci move with femur (they are fixed but they will
move in a circular motion)
• Lateral moves 20 - 24 mm together with condyle of the femur
• Medial less mobile 10 -15 mm (remember that the knee is a hinge
joint, and a hinge joint mainly move in flexion and extension pattern
but there will be a slight lateral and medial movements in the knee
joint because of the menisci, again the lateral is more than the medial
because of the transverse ligament) and you will see that in the locking
and unlocking of the knee later in this lecture.
Lateral meniscus bears more load, because it’s more circular, bigger, tougher
and thicker than the medial one.
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The lateral meniscus is rounded, thicker and more compacted toward the
midline so that it will bear more force, the medial is more oval and more open
in the middle.
The rotation occurs between the lower surface of the meniscus and the tibia.
The movement of the tibia (rotation) will drag these menisci and move them
either laterally or medially. There is an elastic attachment between the tibia
and the menisci (made of elastic fibers), which is very weak attachment, and
this elasticity will allow the menisci together with the condyles of the femur
to move on the tibia. *very important.
The difference between the two menisci
The medial meniscus
• It is relatively immobile. (even though there is 10-15 mm degrees of
rotation)
• It is c-shaped/semicircular fibrocartilaginous disc. Now the doctor told
us the difference between hyaline and fibrocartilaginous cartilages.
They both contain chondrocyte, the fibrocartilaginous only contains
fibers but the amount of chondrocytes is less than the hyaline
cartilages. The doctor said that the meniscus contains high amount of
chondrocytes along with fibers so they are something in between
hyaline and fibrocartilaginous (‫ محيّرين‬as he said) but mainly are
fibrocartilaginous.
• Peripheral margin adhere to tibial collateral ligament. Now, if they
adhere to the tibia how they move?! Well, there is an adherence but
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it’s an elastic, mobile, and loose adherence and because of that it
sometimes will rupture and dislocate.
• More liable to injury. Because it’s wider and thinner.
The lateral meniscus
• It is more round/circular in shape.
• The posterior end of the meniscus is attached to femur through 2
meniscofemoral ligaments. That’s why the lateral can move more
freely on the femur rather than the medial one and it has a thicker
attachment to the femur rather than the tibia.
• The tendon of popliteus and fibrous capsule separate it from lcl.
• Mobility of posterior end is controlled by popliteus and 2
meniscofemoral ligaments. And because of the popliteus muscle it has
wider range of movement.
Transverse ligament
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IT CONNECTS THE ANTERIOR ENDS OF MEDIAL AND LATERAL
MENISCI, allowing the ACL to pass posterior to it, and because the lateral is
more mobile the ligament will hold them together. The motion is continuous,
the femur will drag the lateral meniscus and the transverse ligament will drag
the medial together with it. The medial meniscus will move as a follower
because it’s not properly attached to the condyle femur as the lateral one. So
the movement will occur as a cascade: the femur lateral condyle will move
almost 32 degrees => the lateral meniscus move 20-24 degrees => the
transverse ligament taut => the medial meniscus move 10-15
Meniscofemoral ligaments * the doctor mentioned them quickly*
• The ANTERIOR MENISCOFEMORAL LIGAMENTS (Humphrey) is
attached to lateral aspect of the medial femoral condyle in front of the
PCL
• The POSTERIOR MENISCOFEMORAL LIGAMENTS (Wrisberg) is
attached posterior to the PCL
• The posterior meniscofemoral ligament is usually present
• Vary in size
Arcuate ligament * the doctor mentioned them quickly*
• Its posterior expansion of the Short Lateral Ligament
• It extends backwards from head of the Fibula, arches over the
popliteal tendon and is attaches to posterior border of the
intercondylar area of the tibia
• Fibers oriented in various directions
• Y-shaped configuration over popliteus
• Medial limb terminates into oblique popliteal ligament
• Lateral limb invariable present, and is less distinct
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Relations of the knee
ANTERIORLY:• ANTERIOR BURSA, LIGAMENTUM PATELLAE, PATELLAR PLEXUS. They
are separated by the suprapatellar bursa (an extension to the synovial
membrane)
Posteriorly: - the diamond shaped popliteal region. The inferior lateral and
medial borders are made of the heads of the gastrocnemius. The superior
lateral border is made of the biceps tendon, where the medial is made of the
semitendinosus
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• Popliteal vessel (the popliteal artery is a continuation of the femoral
artery after it passes the adductor hiatus. And the popliteal vein is a
continuation of the greater saphenous vein and the deep veins of the
leg and they will meet in the inferior tip of the popliteal region, then it
will be called the femoral vein in the thigh) , tibial nerve (a
continuation of the sciatic nerve) , peroneal nerve, gastrocnemius,
plantaris, semitendinosus, semimembranosus, gracilis, popliteus. The
popliteal vessel is located in what is called the popliteal fossa which is
covered by fascia together with the semimembranosus,
gastrocnemius, and biceps femoris
Now, let’s talk about the locking and unlocking states
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When you stand in a fully extended position and your legs is tight ("lock
yourself) you will feel tired in a few minutes
When you walk you will move in a lateral rotation and you will “unlock” your
knees by flexion and you relief your
Now the doctor told us to stand and try the locking and unlocking states and…
look! Just ask anyone who attend the lecture and he will told you what the
doctor did… I need to finish this sheet… I don’t have much time.
So when you extend your knee backward and feel that you are in a tight
position this is “locking”, and when you walk you do a lateral rotation and
relief the “locking” state (unlocking). The doctor said: “if you don’t practice
it you won’t be able to learn it”, so stand up and try it. The popliteus muscle
has many roles, and “if it not present I don’t know what will happen” the
doctor said that. You won’t have attachment to the arcuate ligament, you
won’t have the popliteal tendon, you won’t have the locking and unlocking
position
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THIS IMAGE IS VERY VERY IMPORTAN!!!
And that’s it … we’re done with the joints … what else?! Still we have
The anatomy of the inguinal region.
Remember when we discussed the abdominal muscles, we said that the
external oblique muscle will reflect on itself, and extends from the anterior
superior iliac spine to the symphysis tubercle and form what is known as the
inguinal ligament. This muscle extends all the way medially to the pubic
symphysis.
You can see below the mid-inguinal point which occurs in the middle
between the ASIS to the pubic symphysis, while the midpoint of the inguinal
ligament (the midpoint within the inguinal ligament) is located more lateral
(between the ASIS and the pubic tubercle). So, just know the difference
between the mid-inguinal point and the midpoint of the inguinal ligament
which is more inferior and more lateral.
The inguinal canal is: a canal -About 4 cm long- that resembles a box, this
box has two ends (openings) and four walls. So, it has a roof, floor, anterior
wall, and posterior wall, and the openings are represented by the superficial
and the deep inguinal rings. In neonates, the deep ring lies almost directly
posterior to the superficial ring.
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Imagine the right side inguinal canal viewed from the front as a box with anterior & posterior
walls, a roof & floor. The arrow extends from the deep (posterior and lateral to the anterior wall)
into the superficial inguinal rings, and indicates that structures can run through it from lateral to
medial – e.g. in males it transmits the spermatic cord, and in females, the round ligament of the
uterus.
Inguinal canals – why have them?
• Allow contents of the scrotum to communicate with intra-abdominal
contents (abdominal cavity).
• Allow the passage of the spermatic cord from the scrotum (or testis)
to the pelvic cavity
• Prevent mobile intra-abdominal contents (e.g. intestine) from
entering the scrotum and possibly becoming damaged, while at the
same time allow the passage of blood vessels, nerves, lymphatics, vas
deferens etc. to supply the scrotal contents
• When this canal becomes weak it won’t prevent the intra-abdominal
content from entering the scrotum and that what is known as direct
hernia.
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The external oblique muscle will fold and form the ligament. Medial to the
ligament, and lateral to the symphysis pubis, there will be a triangular opening
(the superficial inguinal ring in the image below) in the aponeurosis of the
external oblique muscle. this opening is only covered by the skin and the
subcutaneous fascia, and fascia that covers the abdomen, so it is the weakest
point of the inguinal region, and is enforced by the coverings of the spermatic
cord, some of these coverings will pass with the spermatic cord all the way
inside, and some will be inserted to the borders of this opening. It allows the
spermatic cord and the structures of the scrotum to come into the abdomen.
*for me the image below is the most important one, so refer to it when you
want to see the structures of the inguinal canal
See the triangular opening lateral to the Linea Alba and lateral to the
symphysis pubis. See also the coverings of the spermaitc cord, it has a
cremasteric muscle, internal spermatic fascia, and external spermatic fascia
which attaches and partially protects the superficial inguinal ring. Know that
the internal spermatic fascia passes to the deep ring while the external fuses
to form the borders of the superficial ring. The superficial ring is 3-5 cm
medially to the deep one
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The anterior wall
• formed by the aponeurosis of the external oblique muscle, reinforced
in its lateral third by the fibers of origin of the internal oblique, and
posteriorly by the internal oblique and the transversus muscles
• This wall is therefore strongest where it lies opposite the weakest part
of the posterior wall --- the deep inguinal ring.
The triangular opening exists on the anterior wall. Most of the external oblique
is made of the aponeurosis in this region. The anterior wall is made of the
external oblique and is enforced posteriorly by the internal oblique and the
transversus muscle.
The posterior wall
• formed by the transversalis fascia, reinforced in its medial third by the
conjoint tendon (the common tendon of insertion of the internal
oblique and transversus muscles)
• The wall is therefore strongest where it lies opposite the weakest part
of the anterior wall --- superficial inguinal ring.
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The deep ring (or the posterior wall) is more enforced because of the presence
of the internal oblique, external oblique and the transversus laterally and
medially by the conjoint tendon.
The conjoint tendon is formed by joining the aponeurotic structures of the
internal oblique and the transversus and is inserted into superior to the
posterior part of the symphysis. It does not enforce the superficial ring – or
just partially enforce the posterior wall and form the roof of the canal.
The spermatic cord passes through the internal oblique, all the way to the deep
inguinal ring in the transversus abdominis. So, it’s an oblique canal passes
through the abdominal muscles, where the inguinal ligament goes form lateral
to medial.
Inferior wall or the floor of the canal
• formed by the rolled-under inferior edge of the aponeurosis of the
external oblique muscle (the inguinal ligament) and at its medial end
the lacunar ligament
The superior wall –formed by the conjoint tendon
• Formed by the arching lowest fibers of the internal oblique and
transversus abdominis muscle.
Superficial inguinal ring
• Triangular shaped defect
• Base is formed by the pubic crest
• The crura – margins of the ring, give origin to the external spermatic
fascia
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CONTENTS OF INGUINAL CANAL:
• MALE:
spermatic cord & ilio-inguinal nerve (L-1)
• FEMALE:
round ligament of uterus & ilio-inguinal nerve (L-1)
SPERMATIC CORD:
• Collection of structures that pass through the inguinal canal
• Begins in the deep inguinal ring. Ends in the testis.
• Spermatic cord is covered by three concentric layers of fascia derived
from the layers of anterior abdominal wall.
CONTENTS OF SPERMATIC CORD:
• Vas deferens, Artery of the vas deference
• Testicular artery
• Cremasteric artery
• Panpiniform plexus (testicular vein)
• lymphatics
• Sympathetic nerves
• Genital branch of genitofemoral nerve
• Processus vaginalis
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Hernia
Sorry to say that but here the doctor begins the process of “shalfagation”,
and I just copied the slides. And I’m sure that this is the fastest “herniation
lecture” in the history!!
Define hernia
The protrusion of a structure from its normal cavity through an abnormal
opening
How can they be described?
Reducible: Contents easily put back
Incarcerated: Cannot be reduced
Strangulated: Contents are stuck, and there is constriction of the tissues at
the neck of the hernia, leading to reduced venous drainage and arterial
occlusion
Inguinal hernia
• The posterior wall of the canal is particularly weak laterally because of
the deep inguinal ring
• The anterior wall opposite the deep ring is reinforced laterally by the
internal oblique m.
• A hernia (e.g. of small bowel) that comes through the deep inguinal
ring will have to travel along the inguinal canal as it cannot push into
the reinforced layers of muscle in the anterior wall of the canal directly
opposite the deep inguinal ring
• The anterior wall of the canal is weak medially where the superficial
inguinal ring is situated
• The posterior wall, opposite the superficial ring, is reinforced medially
by the conjoint tendon that is formed by fibres of the internal oblique
and transversus abdominis muscles
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• Abdominal contents cannot normally force themselves through the
superficial ring directly because of the reinforced posterior wall
medially
Direct hernia:
Medial to inferior epigastric vessel
Direct goes directly through Hesslebach’s Triangle
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Indirect hernia
Lateral to inferior epigastric artery
Passes through processus vaginalis via deep & superficial inguinal rings
Travels into scrotum
Congenital type
Common in males
And guys I just wrote what the doctor said exactly, so if there is something RONG (other than this
word) I tried my best. By the way, I know its “wrong”.
Before you leave, just have a look in this little summary below, and test yourself. Try not to cheat,
it will help you review the lecture easily. 
Done by: does it matter?!
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Fill in the blanks:
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