The knee joint is the largest and most complex joint in the body. It consists of three joints: the medial and lateral condylar joints between the femur and tibia, and the patellofemoral joint between the femur and patella. The knee joint contains numerous ligaments that connect the femur, tibia, and patella, including the anterior and posterior cruciate ligaments, medial and lateral collateral ligaments, and medial and lateral menisci. The knee joint also contains bursae that reduce friction between bones, muscles, tendons, and ligaments during movement.
2. KNEE JOINT: SYNOVIAL JOINT OF CONDYLAR VARIETY
• Knee Joint is largest and most complex joint in the body
• It consist of 3 joints:
• Medial condylar Joint: Between medial condyle of femur and medial condyle
of tibia.
• Lateral condylar Joint: Between lateral condyle of femur and lateral condyle of
tibia.
• Patellofemoral Joint: Between the patella and pateller surface of femur
5. FIBROUS (ARTICULAR) CAPSULE
• Commonly referred to as the capsular ligament
• Deficient anteriorlly
• Anteriolaterally strengthened by Lateral pateller ligament and
Anteromedilly Medial patellar ligament
6. ANTERIOR CRUCIATE LIGAMENT
• The Anterior cruciate ligament attaches to the facet on the anterior part of the
intercondylar area of the tibia and ascends posteriorly to attach to a facet at the
back of the lateral wall of the intercondylar fossa of the femur.
• The Anterior cruciate ligament crosses lareral to the posterior cruciate ligament
as they passes through the intercondylar region.
• The anterior cruciate ligament prevent the anterior dislocation of tibia relative to
femur.
• It is tout during knee extension.
7. POSTERIOR CRUCIATE LIGAMENT
• Posterior cruciate ligament attaches to the posterior aspect of the
intercondylar area of tibia and ascends anteriorly to attach to the medial
wall of the intercondylar fossa of the femur.
• Posterior cruciate ligament resist posterior displacement.
• It touts during knee flexion.
8. MEDIAL COLLATERAL LIGAMENT OR TIBIAL
COLLATERAL LIGAMENT
• Attached proximally to the medial epicondyle of the femur
immediately below the adductor tubercle.
• Below to the medial condyle of the tibia and medial surface of its
body.
• It resists forces that would push the knee medially, which would
otherwise produce valgus deformity.
9. LATERAL COLLATERAL LIGAMENT OR FIBULAR COLLATERAL
LIGAMENT
• Fibular collateral ligament stretches obliquely downward and backward.
• From the lateral epicondyle of the femur above, to the head of the fibula below.
• Seperated from lateral Meniscus by Popliteal tendon and fibrous capsule.
• Tightest in extension,0 to 30degrees
• Becomes looser in flexion>30 degrees
10.
11. MEDIAL MENISCUS
• It is relatively immobile
• It is C shaped/semilunar(Fibrocartilagenous disc)
• Peripheral margin adherent to tibial collateral ligament.
• More liable to injury.
12. LATERAL MENISCUS
• It is more round/circular in shape
• The posterior end of the Meniscus is attached to femur through two meniscofemoral
ligament.
• The tendon of Popliteal and fibrous capsule separate it from Lateral collateral ligament.
• The mobility of posterior end is controlled by Popliteal and 2 meniscofemoral ligament.
13. FUNCTION OF MENISCI
• Shock absorption
• Redistributes force
• Spread synovial fluids
• Minimal effect on stability
• On rotation menisci move with femur
• Lateral moves 20-24 mm
• Medial less mobile 10-15 mm
• Lateral menisci bear more load.
14. OBLIQUE POPLITEAL LIGAMENT
• It is an extension from semimembranosus tendon close to its insertion to the tibia
• Oblique Popliteal ligament passes upward and laterally.
• It is attached above to the upper margin of the intercondyloid fossa and posterior
surface of the femur close to the articular margins of the condyles.
• Below to the posterior margin of the head of the tibia.
15. ARCUATE POPLITEAL LIGAMENT
• It is Y-shaped.
• attached to the posterior portion of the head of the fibula. From there it goes to its two
insertions; the medial one goes over popliteus muscle and blends with the oblique
popliteal ligament, the lateral one to the Lateral epicondyle of the femur and blends there
with the lateral head of gastrocnemius muscle.
16. BURSAE
• As many as 13 bursae have been described around the knee joint
• Four are anterior
• Four are lateral
• Five are Medial
17. ANTERIOR BURSAE
• These are four in numbers:
• Subcutaneous prepatellar bursae
• Subcutaneous infrapatellar bursae
• Deep infrapatellar bursae
• Suprapatellar bursae
18. LATERAL BURASE
• There are four lateral bursae:
• A bursae deep to lateral head of gastrocnemius
• A burase between Fibular Collateral ligament and the biceps femoris.
• A burase between Fibular Collateral ligament and tendon of popliteus.
• A bursae between tendon of popliteus and lateral condyle of tibia.
19. MEDIAL BURSAE
• There are Five medial bursae:
• A bursae deep to the medial head of gastrocnemius
• The Anserine burase
• A bursa deep to the Tibial collateral ligament.
• A bursae deep to semimembranosous.
• Occasionally a FIFTH bursae present between tendon of semimembranosous and
Semitendinosus.
20. RELATIONS OF KNEE
• Anteriorly:
• Anterior bursa
• Ligamentum Patellae
• Patellar plexus
23. LOCKING OF KNEE
• It is the terminal stage of knee extension.
• The tibia is laterally rotated and femur is Medially rotated.
• This rotatory movement locks the joint(which means that the joint cannot be flexed unless
it is unlocked by reverse rotation)
• In full extension with the locked knee,all the muscles are stretched and the joint is stable.
• Produced by biceps femoris muscles.
24. UNLOCKING OF KNEE
• “Unlocking” of knee.During knee flexion first it is necessary to “untwist” and reduce
tension within the major ligament of knee joint.
• Contraction of popliteus muscles,
• Because of contraction of popliteus muscles, Femur laterally rotates on the tibia and pulls
the lateral Meniscus posteriorly.
• Once the femur is laterally rotated the knee is said to be unlocked.