Clinical Anatomy of the Lower Limb 2 Flashcards
Knee Joint
Type: hinge
β articulation between the femoral condyles and superior aspect of tibial
condyles
β articulation between the patella and the femur
Menisci
-fibrocartilaginous C-shaped
cartilages
medial and lateral meniscus are interconnected by anteriorly by a transverse ligament of
the knee
Patellar ligament
the continuation of the quadriceps femoris tendon
inferior to the patella
tibial (medial) collateral ligament
medial femoral condyle to the medial aspect of
tibia
fibular (lateral) collateral ligament
lateral femoral condyle to the
fibular head
Anterior cruciate ligament
Prevents anterior displacement of the tibia relative to the femur β’ prevents posterior displacement of the femur -Anterior drawer test
Posterior cruciate ligament
Restricts posterior displacement of the tibia relative to the femur β’ restricts anterior displacement of the femur -Posterior drawer test
Locking Mechanism
When standing, the knee joint is locked into
position, thereby reducing the amount of
muscle work needed to maintain the
standing position.
Locking mechanism is achieved by:
β The change in the shape and size of the
femoral surfaces that articulate with the
tibia during extension. The joint surfaces
become larger and more stable in extension.
β Medial rotation of the femur on the tibia
during extension that tightens all the
associated ligaments
how does the popliteus muscle unlock the knee
unlocks the knee by
initiating lateral rotation of the femur on
the tibia.
Genu Varus
Changes in the distribution of weight to the tibia can cause increase the space between the femur and patellar
Genu Valgus
Changes in the
distribution of weight to
the tibia can cause a decrease in the space between the
femur and patellar
Unhappy Triad
Excessive force to the lateral side of the knee (valgus pressure)
Suprapatellar bursa:
continuous with the
articular cavity superiorly between the distal
end of the shaft of the femur and the
quadriceps femoris muscle and tendon
bursae associated with the knee but
not normally communicating with the
articular cavity include
β subcutaneous prepatellar bursa (housemaid knee) β deep and infrapatellar bursa β subcutaneous infrapatellar bursa (clergymanβs knee)
Knee bursae
β’ Anteriorly, the synovial membrane is
separated from the patellar ligament by an infrapatellar fat pad
leg compartments ;Anterior compartment
β’ extensor compartment β’ deep fibular nerve β’ Dorsiflexion (extension) of foot β’ inversion
leg compartment ; Posterior compartment
β’ flexor compartment β’ tibial nerve β’ planterflexion (flexion) of the foot β’ inversion
leg compartment :
β’ superficial
fibular nerve
β’ eversion of
foot
gastrocnemius
β’ tibial nerve
β’ plantarflexes ankle
join/foot and flexes
the knee/leg
plantaris (vestigial)
tibial nerve
β’ plantarflexes ankle
join/foot and flexes
the knee/leg
soleus
β’ tibial nerve
β’ plantarflexes ankle
join/foot
triceps surae
propels the body
forward when walking
Popliteal fossa
Diamond-shaped space behind the knee
joint
popliteus
- tibial nerve
* unlocks the knee
flexor digitorum longus
- tibial nerve
* flexes lateral 4 toes
flexor hallucis longus
- tibial nerve
* flexes the great toe
tibialis posterior
β’ tibial nerve β’ plantarflexion & inversion of ankle joint/foot β’ support arch of foot
extensor digitorum
longus
β’ deep fibular nerve β’ dorsiflexion of ankle joint/ foot β’ extension of four lateral toes
fibularis
tertius
β’ deep fibular nerve
β’ Dorsiflexion and
eversion of ankle
joint/foot
extensor hallucis
longus
β’ deep fibular nerve β’ dorsiflexion of ankle joint/foot β’ extension of big toe
tibialis anterior
β’ deep fibular nerve β’ dorsiflexion and inversion of ankle joint/foot β’ Support arch of foot
Extensor digitorum brevis
Deep fibular nerve
β’ Extension of toes II-IV
Extensor hallucis brevis
Deep fibular nerve
β’ Extension of MTPJ of
big toe
fibularis longus
β’ superficial fibular nerve
β’ eversion of ankle
joint/foot
β’ support arch of foot
fibularis brevis
superficial fibular nerve
β’ eversion of ankle
joint/foot
Posterior tibial artery origin ;
β originates from the popliteal artery in the popliteal fossa and enters the posterior compartment of the leg
Posterior tibial artery gives which branches :
- fibular
* circumflex fibular
what supplies the posterior and lateral compartments of the leg
Posterior tibial artery4
Perforating arteries from the
fibular artery supply the
lateral compartment
what supplies the anterior compartment of the leg :
Anterior tibial artery
Anterior tibial artery origin
Passes forward into the anterior
compartment of the leg through an
aperture in the interosseous
membrane
Tibial nerve injury
Patients are unable to plantarflex the
ankle joint. They also have decreased
inversion of the ankle joint.
Loss of sensation on the posteriorlateral leg and the sole of the foot
All functions (except for extension) of the intrinsic joints of the feet will be lost
Common fibular nerve injury
lateral and anterior compartments affected
β’ Foot drop is the result due to loss of
dorsiflexion. There will also be decreased
inversion of the foot. There will be loss of
extension of the digits
high
-stepping gait and/or swing out the leg
- Loss of sensation on the inferior-anterior
leg and dorsum of foot