U.RADHAKRISHNAN.M.P.T
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Knee Joint produces Functional shortening
and Lengthening of extremity
Knee complex plays a major role in
supporting the body in Dynamic and Static
situation
The Knee complex is composed of
TIBIOFEMORAL JOINT
PATELLOFEMORAL JOINT
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ARTICULATION:
ON DISTAL FEMUR-----Convex,Asymmetric,Medial and Lateral
condyle
ON PROXIMAL TIBIA------Concave,Asymmetric,Medial and Lateral
Plateau
The FEMORAL CONDYLES are twice as large
as length of TIBIAL CONDYLES
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Fibrocartilaginous Joint Disc
Medial and Lateral Menisci---asymmetric
The two ends are called horns
Coronary ligament attaches the Menisci to
Tibial plateau
Transverse ligament joins the two Menisci
Medial Menisci is more fixed and attached
to capsule and Medial collateral ligament.
They are less mobile and prone to
injury
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Stability & Mobility Function
STABILITY:
Deepens articular surface
Keeps the joint surface tight
Distribute the load
MOBILITY:
Reduces friction
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Joint capsule encloses Tibiofemoral and
Patellofemoral Joint.
It is large,lax,with many folds
The deep folds of capsule forms the Bursae
Suprapatellar Bursae
Prepatellar Bursae
Infrapatellar Bursae
Subpopleteal Bursae
Gastrocnemius Bursae
INTRACAPSULAR LIGAMENT
ANTERIOR CRUCIATE LIGAMENT: Extends
superiorly and posteriorly attached to posterior
part of inner aspect of Lateral condyle of Femur.It
is more prone for injury eg. Foot ball players
POSTERIOR CRUCIATE LIGAMENT: Extends
superiorly and anteriorly to attach to anterior
portion of inner aspect of Medial femoral condyle
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MEDIAL COLLATERAL LIGAMENT:(TIBIAL)
Extends from medial Femoral condyle to
medial part of proximal Tibia,attaches with
medial meniscus
LATERALCOLLATERALLIGAMENT:(FIBULAR)
Extends from Lateral Femoral condyle to
head of Fibula
STABILITY
LIGAMENTS
MUSCLES
MEDIAL STABILITY
MEDIAL COLLATERAL
SEMIMEMBRANOSUS
LATERAL STABILITY
LATERAL COLLATERAL POPLITEUS.IT BAND
ANTERIOR STABILITY
ANTERIOR CRUCIATE
QUADRICEPS,
PATELLA
POSTERIORSTABILITY POSTERIOR
CRUCIATE
BICEPS
FEMORIS,POPLITEUS
ANTEROMEDIAL
MEDIAL
COLLATERAL,ANTERI
OR CRUCIATE
QUADRICEPS
ANTERIOLATERAL
LATERAL
COLLATERAL,POSTER
IOR CRUCIATE
POSTERIOR MEDIAL
OBLIQUE POPLITEAL
LIGAMENT
SEMIMEMBRANOSUS
POSTERIOR LATERAL
ARCUATE POPLITEAL
POPLITEUS
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A Line runs along the shaft of the Femur
and shaft of Tibia they form angle of 170
to 175 degree
When the angle is less than 165 degree an
abnormal condition called GENU VALGUM,
The medial aspect of knee is subjected to
distraction force
When the angle is more than 180 degree an
abnormal condition called GENU VARUM
The medial aspect of knee is subjected to
Increase compression loading
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FLEXION- EXTENSION
Saggital plane,Mediolateral axis
ROTATION
Transverse plane,vertical axis
Flexion active range is 120 degree restricted
by contact of posterior muscle,active
insufficiancy
passive range is 130 degree
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During complete Extension, the Tibial
tubercle locks in to intercondylar fossa of
Femur, it is the closed packed position.
ROTATION:
It is not possible when knee in full
Extension as ligaments are taught
When Knee in 90 degree Flexion---Rotation is possible, Lateral rotation is 40
degree and Medial rotation is 30 degree
ABDUCTION can be done passively
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FLEXION AND EXTENSION:
During Flexion from full Extension Femoral
condyles roll in an posterior direction with
sliding anteriorly.In First part of Flexion
consist of Rolling and spinning
During Extension from full Flexion
Femoral condyles roll in an anterior
direction with sliding posteriorly.In last few
degrees of Extension Femoral condyles Roll
and Spin on Tibia
Pure Rolling will move condyles out
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The spin of Femur in last few degree of
Extension causes a Medial rotation of
Femur on Tibia will keep joint in closed
packed position, so Femoral rotation is
called LOCKING or SCREW HOME
MECHANISM.The Knee is Unlocked by
Lateral rotation of Femur
In open Kinematic chain Tibia laterally
rotates on Femur during last few degrees of
Extension to produce LOCKING.Unlocking
by Medial rotation.
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EXTENSORS
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QUADRICEPS
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The efficiency of Quadriceps depends on
PATELLA,it increases the moment arm
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Supports the body weight
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Resist the force of gravity
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FLEXORS
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HAMSTRINGS
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Work more effectively in Knee if they are
lengthened over a Flexed hip
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MEDIAL MENISCUS INJURY:
More common,it is fixed, attached to
capsule
ANTERIOR CRUCIATE LIGAMENT INJURY:
More common in foot ball players
GENU VALGUM/GENU VARUM
PREPATELLAR BURSITIS:
Inflammation of Prepatellar bursae,common
in workers who kneel and work
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Patella is the largest sesamoid bone
ARTICULATION:
Patella is attached to the patellar surface on
distal Femur.
During Flexion , from Full Extension patella
slides downwards and rest in intercondylar
notch
During Extension,from Full Flexion patella
slides upwards
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QUADRICEPS ANGLE( Q ANGLE ):
The angle formed by resultant vector of
Quadriceps and the pull of ligamentum
patella
It is found by drawing two lines
1.From ASIS to midpoint of Patella
2.From Tibial tubercle to midpoint of Patella
The normal angle is 15 degree
When the angle is large -----Lateral pull on
patella is increased.
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PATELLA ALTA:
High riding of patella(elevation),there is
lateral stress to patella and instability.
CONDROMALACIA PATELLA:
Softening of articular cartilage of
Patellofemoral joint.
Later stage fibrillation and thining of
cartilage occurs and subchondral bone
exposed.