This lecture explains the different aspects of knee joint along with the associated ligaments and muscles, along with the relations and associated structures.
Outline of Lecture
Knee Joint
Largest synovial joint
Modified hinge joint
Compound joint-Bicondylar & gliding / sellar joint
Shape Of Femoral & Tibial Condyle
MFC: longer, narrower & oval
LFC: Shorter, rounded
MTC: Oval with long anteroposterior axis
LTC: circular
Capsule
Attached to the margins of articular surfaces & surrounds the sides & posterior aspect of joint
In front – absent
On each sides of patella- capsule is strengthened by expansions from tendons of VM & VL
Behind the joint – capsule is strengthend
Opening in the capsule behind the lateral tibial condyle
Extracapsular ligaments
Ligamentum patellae
Lateral collateral
Medial collateral
Oblique popliteal
Arcuate popliteal ligament
Tendon of popliteus intervenes b/w FCL & LM
MCL is firmly attached to MM
Intracapsular ligaments
Anterior cruciate
Posterior cruciate
Menisci (avascular except at the periphery)
Anterior meniscofemoral (Humphry)
Posterior meniscofemoral (Wrisberg)
Transverse ligament
Coronary ligaments
Cruciate ligaments
ACL prevents posterior displacement of femur on tibia or when the knee is flexed it prevents the tibia from being pulled anteriorly.
PCL – vice versa
Medial Meniscus
Semicircular
Broader behind than in front
Anterior horn
Posterior horn
Attachments-more fixed
Lateral Meniscus
Circular
Uniformly wide
Anterior horn
Posterior horn- Ant & post meniscofemoral lig of Humphry & Wrisbery
Separate from capsule-less fixed
Lateral Meniscus
Synovial membrane
Lines the capsule
Attached to the margins of articular surfaces & to peripheral edges of menisci
Semimembranosus bursa
Bursae around knee joint
Relations of Right knee joint
Nerve Supply of Knee Joint
Femoral
Obturator
Common peroneal
Tibial
Knee movements
Locking of knee joint
Moving into extension from a flexed position:
Articular surface of LFC stops and LFC completes its extension excursion 30 degrees short of full extension.
The surface for articulation still exposed on the MFC, as a result Medial rotation of femur accompanies final stages of extension
MFC accommodates the remainder of exposed articular surface
Passive medial rotation of femur secures the joint in 5 – 10 degrees of hyper extension
Promotes max. contact b/w articular surfaces of femoral & tibial condyles
Renders ligaments taut
Joint is maintained in the stable extended position.
Unlocking of Knee joint
Brought about by popliteus m that pulls the lateral condyle posteriorly laterally rotating the femur
Ligaments relax
Unlocking of knee joint
Locking of Knee joint
Flexion / extension – upper joint compartment
Rotation – lower joint compartment
Ankle joint
Between lower end of tibia, two malleoli and body of talus
Synovial hinge variety
Knee joint injuries
Runner’s syndrome
Q-Angle
Abnormal q angle
