KNEE ANATOMYRHS Sports Medicine

TIBIA

FIBULA

FEMUR

12

3

4

PATELLA

BONY ANATOMY OF THE KNEE

• The joint line of the knee is where the tibia and the femur meet.

• PALPATE THE LATERAL JOINT LINE.

• PALPATE THE MEDIAL JOINT LINE• •PALPATE THE HEAD OF THE FIBULA

KNEE JOINT LINE

• The tibia is main weight bearing bone of the lower leg.

• The proximal end of the tibia is part of the knee joint.

• The top of the tibia is flat and is called the tibial plateau.

LABEL TIBIA ON YOUR WORKSHEET. CIRCLE THE TIBIAL PLATEAU ON YOUR WORKSHEET.

TIBIA

• The fibula is a NON- weight bearing bone on the lateral aspect of the lower leg.

• The proximal end of the fibula is near the knee joint but is not considered an actual part of the joint.

LABEL FIBULA ON YOUR WORKSHEET.

FIBULA

• A common name for the femur is the “thigh bone”.

• The femur is the longest, largest, strongest bone in your body.

• When you stand or walk, all the weight of your upper body rests on them.

• The femur is part of the knee joint distally

and the hip joint proximally.

FEMUR

LABEL THE FEMUR ON

YOUR WORKSHEET

• The common name for the patella is the “kneecap”.

• The patella is an irregularly shaped sesamoid bone.

• The anterior surface is smooth and rounded.

• The posterior surface is wedge-shaped.

• It is possible to break your kneecap!

PATELLA

FEMUR?

?FIBULA ?TIBIA

?PATELLA

FEMUR

FIBULA

TIBIA

PATELLA

BONES OF THE KNEE JOINT

KNEE MOTIONS

FLEXIONBending the knee

Hamstring Muscles

EXTENSION:Straightening the

legQuadriceps Muscles

KNEE MOTION• The knee joint is a

hinge joint.• Flexion and extension

happens between the femur and the tibial plateau.

• The patella articulates with the femoral groove.

PATELLAR TENDONThe patellar tendon

attaches the patella to the tibial tuberosity.

DISTALLY, all Quadriceps muscles attach firmly to the superior edge of the patella.

KNEE LIGAMENTS• Ligaments run

from bone to bone. There are 4 main ligaments in the knee.

• Ligaments HOLD bones together.

• Ligaments are NOT involved in moving a joint!

• They have different shapes. Some ligaments are like cords (lateral). Some are thin and wide (medial).

(ANTERIOR VIEW)

(POSTERIOR VIEW)

KNEE LIGAMENTS – MEDIAL

Medial Collateral Ligament

(MCL)•Attaches to the femur and to the tibia.

•2 layers Thick and flat

Outer = longerInner = shorter

Stronger than lateral ligament and more likely to be injured

(MEDIAL VIEW)

(LATERAL VIEW)

KNEE LIGAMENTS - LATERALLateral CollateralLigament(LCL)

•Attaches to the femur and the head of the fibula.

•Easily palpated along the lateral aspect of the knee when knee is extended.

•Cord-like in shape. Less likely to be injured

(ANTERIOR VIEW)

KNEE LIGAMENTS: INTERNAL

ACLA nterior

C ruciate

L igament

The ACL attaches to the femur and to the tibia in the center of the knee joint.

It attaches posteriorly on the femur but angles forward to attach at the front of the tibial plateau.

femur

tibia

MCL

LCL

KNEE LIGAMENTS: INTERNAL

ACLKeeps the tibia

from moving forward on the

femur(Anterior Translation)

KNEE LIGAMENTS: INTERNAL

The PCL attaches in the opposite direction of the ACL - anteriorly on the femur but angles backward to attach over the edge and in the back of the tibia.

It crosses the ACL inside the knee joint.

PCLP osterior

C ruciate

L igamentfemur

tibia

KNEE MUSCLESQUADRICEPS (4)

Rectus femorisUnderneath(Vastus Intermedius)Vastus MedialisVastus Lateralis

Major Motion:Extension of the Knee

QUADRICEPS #1

Rectus femoris

•Muscle starts on Pelvis•Ends at top of Patella•Crosses two joints

Vastus intermediusUnderneath the rectus femoris

•Muscle starts along the lateral edge of the femur.•Ends at top of Patella.•Hidden underneath the rectus femoris.

QUADRICEPS #2

Front View

Vastus Medialis

•Muscle starts along the medial edge of the femur.•Ends at top of Patella.•Upper part hidden under other muscles.•Can be palpated near the knee.

QUADRICEPS #3

Front View

Vastus Lateralis

•Muscle starts along the lateral edge of the femur•Ends at top of Patella.•Upper part hidden under other muscles.•Can be palpated near the knee.

QUADRICEPS #4

Front View

Rectus femoris

(Vastus Intermedius)

Vastus Lateralis

Vastus Medialis

Major Motion:Extension of the Knee

QUIZ - QUADS

KNEE MUSCLESHAMSTRINGS (3)

Biceps femorisSemitendonosusSemimembranosus

Major Motion:Flexion of the Knee

HAMSTRING #1

Biceps femoris

•Muscle has two starting points:

•Ishial Tuberosity (bone you sit on) and along back of femur

•Ends at Head of Fibula

•Crosses two joints

HAMSTRING #2

Semitendonosus

•Muscle originates on the Ishial Tuberosity

•Ends at medial edge of tibia.

•Inserts over the top of the semimembranosus, almost a common tendon.

HAMSTRING #3

Semimembranosus

•Muscle originates on the Ishial Tuberosity

•Ends at medial edge of tibia.

•Inserts close to semitendonsus, almost a common tendon.

ARTICULAR CARTILAGE• Articular cartilage

lines the ends of the bones (tibia, femur) and the undersurface of the patella.

• Articular cartilage protects the ends of the bones from the forces of running, jumping and walking.

ARTICULAR CARTILAGE• Articular cartilage can

be torn or crushed by a force injury, such as a sudden hard step or a twisting motion where the femur twists on top of the tibia.

• Articular cartilage can also be worn down by use over time, exposing the bone to the forces of motion.

MENISCUS• Two half-moon

shaped pieces of cartilage that lie between surfaces of the femur and the tibia.

•The meniscus (menisci) absorb the large amount of shock that occurs when the bones crash together while walking, running and jumping.

MENISCUS• The menisci also

provide a “cradle” for the femur to sit atop the tibia instead of slipping off when moving.

• This “cradle” helps to keep the knee joint stable,

MENISCUS

• The meniscus is for the most part “avascular”, meaning it doesn't have blood vessels throughout the tissue.

• Only the outermost 20% of the meniscus has a blood supply.

As a result, a torn meniscus doesn't have the ability to heal itself unless there is just a small tear confined to the peripheral vascular zone.

MENISCUS•MEDIAL MENISCUS

•LATERAL MENISCUS

•Bigger diameter

•Thinner

•Thicker outside edge

•More “C” shaped