Download Knee Joint

Knee joint
D.Rania Gabr
D.Sama.
D.Elsherbiny
Objectives
 Name and identify the bony features of the tibia and fibula.
 Know the type and formation of knee joint.
 Explain the stability factors of the knee joint.
 Identify the muscles that act at the knee joint.
 Know the locking and unlocking mechanism of the knee
joint.
 Understand the functions of the Popliteus and Iliotiabial
tract.
epicondyles
condyles
patella
tibial plateaus
intercondylar notch
Anterior
Posterior
tibial tuberosity
Transverse
Anterior
During the
entire
range of knee
flexion, the
patella
only articulates
with the femur.
Type & Articular Surfaces
Type: synovial Modified
hinge
Knee joint is formed of:
Three bones.
Femoro-tibial articulation:
between the 2 femoral
condyles & 2 tibial
condyles (Type: synovial,
modified hinge).
Femoro-patellar
articulation: between
posterior surface of patella
& patellar surface of femur
(Type: synovial, plane).
Capsule
 Deficient anteriorly & is
replaced by: quadriceps
femoris tendon, patella &
ligamentum patellae.
Bursae Related to Knee
1. Suprapatellar bursa: between
femur & quadriceps tendon.
2. Prepatellar bursa: between
patella & skin.
3. Deep infrapatellar bursa:
between tibia & ligamentum
patella.
4. Subcutaneous infrapatellar
bursa: between tibial tuberosity
& skin.
5. Popliteal bursa: between
popliteus tendon & capsule.
1
2
5
3
4
The synovial membrane
1- lines the capsule,
2- communicates with:
- suprapatellar bursa,
- popliteus bursa,
- semimembranosus burse
- gastrocnemius bursa.
Ligaments: 4 Extracapsular
2
1
1. Ligamentum patellae (patellar ligament): from patella to
tibial tuberosity.
2. Oblique popliteal ligament: extension of semimembranosus
tendon.
3. Medial (tibial) collateral ligament: from medial
epicondyle of femur to upper part of medial surface of tibia (firmly
attached to medial meniscus) and more liable to injury.
4. Lateral (fibular) collateral ligament: from lateral
epicondyle of femur to head of fibula (separated from lateral
meniscus by popliteus tendon).
Structures inside knee
joint
1. The 2 menisci (semilunar cartilages).
2. Transverse ligament
3. The cruciate ligaments.
4. Popliteus tendon.
1. Menisci
 They are 2 C-shaped plates of fibro-cartilage attached
by anterior & posterior horns, to the articular surface
of tibia.
FUNCTION:
 Deepen articular surfaces of tibial condyles.
 Serve as cushions between tibia & femur.
Lateral
meniscus
Medial
meniscus
Size
small
Large
Shape
Circular
Oval
Outer border
separated from lateral
collateral ligament by popliteal
tendon.
attached to the capsule &
medial collateral ligament.
Mobility
More mobile
Less mobile
Liablity for
injury
Less liable
More liable
2. Cruciate ligaments
a. Anterior cruciate ligament:
• Extends from anterior part of
intercondylar area of tibia to
posterior part of lateral condyle of
femur.
• Prevents posterior displacement of
femur on tibia.
• It becomes tense during extension of
the knee joint.
• Prevents hyperextension.
• More liable to injury
b. Posterior cruciate ligament:
• Extends from posterior part of
intercondylar area of tibia to
anterior part of medial condyle
of femur.
• Tightens during flexion of
knee joint
• Prevents anterior
displacement of femur on tibia.
Movements
 FLEXION:
 SGSS.
 popliteus
 EXTENSION:
 Quadriceps femoris and iliotibial tract
 ACTIVE ROTATION (PERFORMED WHEN KNEE IS FLEXED):
A) MEDIAL ROTATION:

SGSS
B) LATERAL ROTATION:

Biceps femoris.
Movements

INACTIVE (DEPENDANT) ROTATION:
A) LOCKING OF KNEE:
 Lateral rotation of tibia, at the end of extension
 Results mainly by tension of anterior cruciate
ligament.
 In locked knee, all ligaments become tight.
 This is done by the action of: Biceps Femoris.
B) UNLOCKING OF KNEE:
 Medial rotation of tibia, at the beginning of flexion.
 Performed by popliteus to relax ligaments & allow
easy flexion and helped by SGS.
Anterior knee in extension
Vastus
lateralis
Vastus
medialis
extensor
retinacula
Patellar
Ligament
Posterior knee in extension
Nerve supply of the
knee joint:
Femoral, obturator, tibial,
and common pernoneal
nerves.
Arterial supply of
knee joint:
From the anastomosis
around knee.
Popliteal fossa
Shape: Diamond-shaped region
Site: Posterior to knee
Boundaries:
 upper medial: SGSS(sartouries-gracilissemimembranosus / semitendinosus
 upper lateral: biceps femoris
 lower medial; medial head of
gastrocnemius.
 lower lateral: lateral heads
of gastrocnemius and plantaries.
 Superficial: Small saphenous vein
draining into popliteal vein
Contents:
 popliteal vessels
 Tibial and Common fibular (peroneal)
divisions of the sciatic nerve.
 Popliteal L.N
Semimembranosus
Semi-tendinosus
Popliteal fossa
Biceps femoris
Gracilis
Sartorius
Plantaris
Med. head of
gastrocnemius
Lat. head of
gastrocnemius
Contents Popliteal fossa
Popliteal
vessels
Short
saphenous
vein
Tibial nerve
Common
peroneal
nerve
Q-Angle
The Q-angle is the angle formed
by :
1-a line from the anterior
superior iliac spine to the
middle of the patella ,and
2-a line from the middle of the
patella to the tibial tuberosity.
Males typically have Q-angles
between 10 to 14o,
females between 15-17o.
Atypical Q-angles
bowleggedness
knock-knees