Download Knee anatomy

Knee Anatomy
Principles of Orthopaedics and Trauma Care
module
January 2009
Alison Holman
The knee joint
• Complex
• Large
• Comprises how many
joints ?
• Joint Biomechanics are
very important
Surface Anatomy
• Using the resource of [email protected], on
the next slide, please label the structures :
A, B & C.
• Self examine or practice on a colleague to
locate these structures,
- Look
- Feel
- Move
Surface anatomy of the knee
B
A
C
The Knee has 3 Joints
• Lateral Tibio-femoral joint
- between the lateral femoral condyle, lateral
meniscus & lateral condyle of the tibia
• Medial Tibio-femoral joint
- between the medial femoral condyle, medial
meniscus & medial condyle of the tibia
• Patello-femoral joint
- between the patella and the patello-femoral
surface
Clinical Application
• Examine the picture on the next page and work out,
 how the tibia is likely to connect ?
 at what angle (varus or valgus) ?
 the implications for joint disease ?
* A line has been drawn in green to suggest the line of the tibia.
Hip / knee alignment
Extra Capsular Ligaments
• Comprise a sheath of ligaments surrounding the
joint consisting mostly of muscle tendons or their
expansions.
• The most obvious of these to the eye and on
examination are the fused tendons of the Quadriceps
Femoris.
• The power of the quadriceps musculature is
important in the stability of the knee.
 Name the 4 muscles of the quadriceps complex &
their origins
Ligaments that strengthen & support the
knee joint
• Patella Ligament
• Medial & lateral Patellar Retinacula
• Oblique Popliteal Ligament
• Arcuate Popliteal Ligament
• Medial Collateral Ligament
• Lateral Collateral Ligament
Application to practice
• Using [email protected], label the identified structures on the
next sheets.
• Then consider the ligament structures, their function &
associated injuries you may have encountered.
or from the media &
SPORTING HEROES …?
Knee, Anterior view
(Knee close up, layer 11)
B
C
A
Knee, Posterior view
(Knee close up, layer 10)
A
B
Knee, medial aspect
(Knee close up, layer 11)
?
Knee, lateral aspect
(Knee close up, layer 11)
?
Intra Articular Ligaments
• Cruciate Ligaments from the word ‘ cross’
• Anterior Cruciate Ligament (ACL),
extends posteriorally & laterally from the area in
front of the intercondylar eminence of the tibia,
to the posterior part of the medial surface of the
lateral femoral condyle.
• It resists forward movement of the femur on the
tibia
• Label the Anterior Cruciate & related Ligament
and any other interesting structures!
Anterior knee
(Knee close up, layer 6)
B
C
A
Posterior Cruciate Ligament (PCL)
• It extends anteriorly & medially from a
depression of the posterior medial
intercondylar area and the lateral meniscus to
the anterior part of the femoral medial
condyle.
• It resists backward displacement of the tibia
• Label the Posterior Cruciate & related
Ligaments
Knee – posterior view
(knee close up, layer 6)
A
B
Bursae !
• Exercise:
What is the function of the bursae … ?
• Name 4 important bursae
Menisci
Structure :
• 2 Fibrocartilage discs
• Poor vascular supply
• Circumferential and radial fibres
• Semi-lunar shape, triangular in cross section,
peripherally attached to the tibial plateau
Tibial Plateau & Menisci
?
?
Menisci
Function :
• Deepens tibial plateau
• Joint stabiliser
• Transmits 50% of the compressive load in
extension
• Transmits 85% of the compressive load
in 90 degree flexion
Nerve Supply :
• derives from sciatic nerve which divides into
Tibial & Common Peroneal nerve
• dermatomes - L1 - L5 supply front of the thigh,
medial/lateral leg areas & sole of foot.
Blood Supply :
• derives from External Iliac artery, becoming the
Femoral artery then the Popliteal artery
• Venous drainage from External Iliac vein
becoming the Femoral vein, then the Popliteal
vein + also from the Right Saphenous vein
Knee Joint Movement & Muscles
•
Flexion,
- by hamstrings assisted by gracilis,
gastrocnemius & sartorius
•
Extension,
- by quadriceps femoris
•
Medial rotation,
- by popliteus
The knee joint
References:
• [email protected]