Knee and Ankle Joints

Knee Joint

Largest and the most complicated joint in the body

synovial hinge, snynovial plane

Two parts of knee joint

synovial hinge

Paired condylar joints between the rounded medial and lateral condyles of the femur above and the corresponding condyles of the tibia

synovial plane

Gliding joint between the patella and the patellar surface of the femur

Patella, ligaments, menisci and bursae of the knee

The articular capsule of the knee joint contains

CAPSULAR LIGAMENT

ligamentous sac that surrounds the articular cavity of a freely movable joint; attached to the bones, completely encloses the joint and composed of an outer fibrous membrane and an inner synovial membrane

Bursa

a fluid filled sac; countering friction at a joint; space

anterior bursa

Suprapatellar

Prepatellar

Infrapatellar – superficial and deep

posterior bursa

Popliteal

Semimembranosus

extrascapular ligaments

Ligamentum Patellae

LATERAL COLLATERAL LIGAMENT

MEDIAL COLLATERAL LIGAMENT

Oblique Popliteal ligament

Ligamentum Patellae

attaches above to the lower border of the patella and below to the tuberosity of the tibia

LATERAL COLLATERAL LIGAMENT

attaches above to the lateral condyle of the femur and below to the head of the fibula

MEDIAL COLLATERAL LIGAMENT

attaches above to the medial condyle of the femur and below to the medial surface of the shaft of tibia

• tibial colateral ligament

Oblique Popliteal ligament

tendinous expansion derived from the semimembranosus muscle

intracapsular ligament

CRUCIATE LIGAMENTS

• ANTERIOR CRUCIATE LIGAMENT

• POSTERIOR CRUCIATE LIGAMENT

ANTERIOR CRUCIATE LIGAMENT

attaches to the anterior intercondylar area of the tibia and passes upward, backward and laterally to attach to the

posterior part of the medial surface of the lateral femoral condyle

• prevents posterior displacement of the femur on tibia

POSTERIOR CRUCIATE LIGAMENT

attaches to the posterior intercondylar area of the tibia and passes upward, forward and medially to attach to the anterior part of the lateral surface of the medial femoral condyle

• prevents anterior displacement of the femur on tibia

ACL

“APEX” ligament – attaches to the Anterior aspect of Tibia and courses Posteriorly and EXternally to attach to the lateral condyle of femur

PCL

“PAIN” ligament – attaches to the Posterior aspect of tibia and courses Anteriorly and INternally to attach to the medial condyle of femur

true for acl

With the knee joint flexed, the ACL prevents the tibia from being pulled anteriorly relative to the femur

true for pcl

With the knee joint flexed, the PCL prevents the tibia from being pulled posteriorly relative to the femur

Menisci

• is a piece of cartilage found where two bones meet

  (joint space); protects and cushions the joint surface and bone ends

• In the knee, the crescent shaped menisci are positioned between the ends of the femur and tibia

Meniscus

LATERAL MENISCUS

MEDIAL MENISCUS nakadikit Kay MCL

Strength of the Knee Joint

Depends on:

* TONE of the muscles acting on the knee joint; most important – Quadriceps femoris

* Strength of the ligaments

ANTERIOR DRAWER SIGN

forward sliding of the Tibia on the Femur due to rupture of

the ANTERIOR CRUCIATE LIGAMENT

POSTERIOR DRAWER SIGN

backward sliding of the Tibia on the Femur caused by rupture of the POSTERIOR CRUCIATE LIGAMENT

Medial Collateral ligament injury

Forced ABDUCTION of the TIBIA on FEMUR

Lateral Collateral

Forced ADDUCTION of the TIBIA on FEMUR

• Less common

MENISCAL INJURY

Medial meniscus is damaged more frequently than lateral because of its strong attachment to the medial collateral ligament which restricts its mobility; injury to the Lateral meniscus is less common because it is NOT attached to the Lateral collateral ligament and its more mobile

3 most commonly injured structures

Tibial collateral ligament, Medial meniscus, ACL (terible triad)

Blow to the lateral aspect of the knee

may injure the Medial/Tibial collateral ligament; the attached medial meniscus may also be torn

Blow to the anterior aspect of the flexed knee

may tear only the ACL

Unhappy Triad of Donoghue

acl, mcl, medial meniscus

Knee Bursitis

inflammation of the bursa at the knee joint

Housemaid’s knee

is also known as Prepatellar bursitis

Calcaneus

largest, forms the prominence of the heel; with SUSTENTACULUM TALI (assists in the support of talus)

Talus

articulates above at the ankle joint with tibia and fibula, in front with navicular and below with the calcaneus; NO MUSCLE ATTACHMENTS

Metatarsals (5) - first

large and strong and plays a role in supporting the weight of the body; Medial side

Metatarsals (5) - fifth

on the lateral which has a prominent tubercle on its base

Phalanges

each toe has three phalanges except the big toe which possesses only 2

Ankle Joint

• Diarthrodial Synovial Hinge joint

• DORSIFLEXION and PLANTARFLEXION – occur at the ANKLE JOINT PROPER or TALOCRURAL JOINT -formed by distal ends of malleoli of fibula and tibia and trochlea of Talus bone

SUBTALAR JOINT

• is the posterior joint between the talus and the calcaneum

• Synovial Plane joint

• INVERSION and EVERSION at the SUBTALAR JOINT

  between the Talus and Calcaneus

MEDIAL / DELTOID ligament

• strong triangular unit connecting the tibia to the navicular, calcaneus and talus

• Attached above to the apex and anterior and posterior borders of the medial malleolus

4 ligaments:

Tibionavicular

* Tibiocalcaneal

* Anterior Tibiotalar

* Posterior Tibiotalar

LATERAL LIGAMENT

is weaker than the medial ligament and consists of three bands

Anterior Talofibular

runs from the lateral malleolus to the lateral surface of talus

Calcaneofibular

from the tip of lateral malleolus downward and backward to the lateral surface of calcaneum

Posterior Talofibular

from the lateral malleolus to the posterior tubercle of talus

Acute Sprains on the LATERAL ANKLE

Excessive INVERSION of the foot with PLANTARFLEXION of the ankle

true

Ant Talofibular and Calcaneofibular ligaments are partially torn

Acute Sprains of the MEDIAL ANKLE

• Excessive EVERSION

• Medial or Deltoid ligament

foot arches

Medial longitudinal, Lateral longitudinal, Transverse

Medial longitudinal

consists of calcaneum, talus, navicular, three cuneiforms and the first three metatarsal bones

• rounded head of the Talus is the keystone

Lateral longitudinal

calcaneum, cuboid, 4th and 5th metatarsal bones

• Cuboid is the keystone

Transverse

bases of the metatarsal bones, cuboid and three cuneiforms

• Cuneiform

SUPPORT OF THE STONE BRIDGE (Support the arches)

Most effective way of supporting the arch is to make the stones wedge shaped; occupies the center of the arch is referred as the KEYSTONE

PES PLANUS / FLAT FOOT

Medial longitudinal arch is depressed or collapsed; foot is displaced laterally and everted

PES CAVUS / CLAW FOOT

Medial longitudinal arch is unduly HIGH