Lower Extremity Flashcards
what is the structural makeup of the foot?
26 bones
- 14 phalanges
- 5 metatarsals
- 7 tarsals
How is the foot divided?
forefoot - toes and metatarsals
midfoot - cuneiforms, navicular and cuboid
hindfoot - calcaneus and talus
What are the tarsals of the foot?
medial, middle and lateral cuneiforms
navicular
cuboid
talus
calcaneus (calcis)
What is the makeup of the great toe?
hallux
2 sesamoids posterior to head of metatarsal
ridge of bone separates sesamoids
What is the makeup of the 5th metatarsal?
head
shaft (body)
base
- tuberosity
- clinically important because of fractures
What is the talus?
most superior tarsal bone
articulates with the tibia, fibula, calcaneus and navicular
head - articulates with navicular (ball and socket)
neck
trochlea or talar domes (2; 1 medial and 1 lateral) part that articulates with the tibia and fibula
What is the inferior surface of the talus?
sulcus tali
- groove that forms the roof of the sinus tarsi
inferior to the neck
3 articular facets
- align with facets of the calcaneus to form subtalar joints: anterior, middle and posterior
What is the calcaneus?
the largest tarsal bone
What is the posterior of the calcaneus?
tuberosity - attaches to ichellies
what is the superior calcaneus?
anterior facet
middle facet
posterior facet
calcanea sulcus (groove that forms the floor of the sinus tarsi)
What is the medial calcaneus?
sustentaculum tali
- shelf to middle subtaylor joint
What is the lateral calcaneus?
lateral process
trochlea
What are the tarsal bone articulations of the talus?
tibiotalar joint
fibulotalar joint
subtler joints (talocalcaneal joints)
talonivacular joint (ball and socket)
What are the 3 ball and socket joints in the body?
hip, shoulder and the talonavicular joint
What are the tarsal bone articulations of the calcaneus?
subtalar joints (talocalcaneal joints)
- 3 joints in total: anterior, middle and posterior
calcaneonavicular joint - anterior process of calcaneus
calcaneocuboid joint
What are the tarsal bone articulations of the navicular?
calcaneonavicular joint
- anterior process of calcaneus
talonavicular joint
all 3 cuneiforms
What is the most medial tarsal bone?
Navicular
What is the most distal tarsal bone?
the cuneiforms
What are the tarsal bone articulations of the cuboid?
calcaneocuboid joint
Joint between cuboid and lateral cuneiform
TMT joint
- with 4th and 5th metatarsals
Navicular
What are the tarsal bone articulations of the cuneiforms?
Medial cuneiform - TMT joint with great toe
Middle cuneiform - TMT joint with 2nd toe
Lateral cuneiform - TMT joint with 3rd toe
Medial part of the cuneiforms must line up with medial aspect of the metatarsals
What are the longitudinal arches of the foot?
Functions as shock absorber and provides leverage while walking
Formed by tarsal and metatarsal bones
Strengthened by ligaments and tendons
1. medial longitudinal arch - higher
2. lateral longitudinal arch
What is the medial longitudinal arch?
originates at calcaneus
rises to the talus
descends through navicular, 3 cuneiforms and ends at the heads of the first 3 metatarsals
What is the lateral longitudinal arch?
originates at calcaneus
rises to the cuboid
descends to the heads of the lateral 2 metatarsals
What is the transverse arch of the foot?
runs side to side to assist the longitudinal arches
formed by the 3 cuneiforms, cuboid, bases of 5 metatarsals
What is the tibia?
larger, medial weight-bearing bone
most proximal
What is the fibula?
lateral, smaller, more posterior bone
most distal
What is the most proximal part of the tibia?
the tibial plateau - the tibial spines separate the medial and lateral condyles
Medial condyle
- curved from anterior to posterior
Lateral condyle
- straight from anterior to posterior
- facet on posterolateral surface where fibular head articulates
slopes posteriorly - 5 degrees
intercondylar eminences or tibial spines sperate the condyles
What is the anterior surface of the tibia?
tibial tuberosity - apophysis
- patellar ligament attaches
Anterior crest
- muscle attachment
What is the distal part of the tibia?
medial malleolus
fibular notch
- lateral side of tibia
- articulation with distal fibula
anterior tubercle
- overlays the fibula
tibial plafond
- french for “Roof”
What is the ankle mortise?
refers to the bony arch or joint formed between the tibial plafond and malleoli
What is the most distal part of the tibia?
the posterior malleolus
What is the proximal part of the fibula?
Head
- articulates with lateral condyle of tibia
- proximal tib/fib joint
Neck
What is the distal part of the fibula?
lateral malleolus
15-20 degrees more posterior compared to medial malleolus
How should the leg be positioned for mortise view?
45 degrees internal rotation to demonstrate proximal tib/fib joint
make the lateral and medial malleolus parallel to the IR with 15-20 degree internal rotation
What is the most proximal part of the tib/fib?
anterior tibial spine
What is the most distal part of the tib/fib?
lateral malleolus
What is the femur?
longest, strongest heaviest bone
Intertrochanteric line joins aterior trochanters
Intertrochanteric crest joins posterior trochanters
Line aspera is a ridge of bone on the posterior femur that is a site for muscle attachment - for quad
What are the parts of the proximal femur?
Head
Neck
Greater trochanter
Lesser Trochanter
what is another name for the head of the femur?
Fovea capitis
What are the characteristics of the femoral neck?
slopes 15-20 degrees posteriorly from the pelvis
to image an AP pelvis internally rotate legs 15-20 degrees or else foreshortening will occur
Where is the lesser trochanter in a true AP pelvis?
posterior to the femur
On a cross table lateral hip where are the greater and lesser trochanters in terms of anatomical position?
greater is superimposed with femoral neck
lesser is located on posterior of femoral neck
Where are the greater and lesser trochanters when not internally rotated for cross table lateral hip?
greater is posterior to femoral neck
lesser is superimposed on femoral neck
When imaging femur from side angle tube 45%. How come?
The side of femur is 135 degrees from attachment in pelvis
What is at the distal end of the femur?
medial femoral condyle
lateral femoral condyle
what makes up the medial femoral condyle?
medial epicondyle
adductor tubercle
- posteromedial aspect
- very useful with repeats of lateral knee
What makes up the lateal femoral condyle?
lateral epicondyle
sulcus terminalis
what is the relationships between the condyles in the distal femur? How does this affet the angling of the CR?
Medial condyle is 5-7 degrees more distal compared to the lateral condyle
angle the tube 5-7 degrees cehalad for a mediolateral knee
angle 5-7 degrees caudad for a lateromedial knee
- xtable for lipoheamarthrosis and trauma is easier in lateromedial
What are the parts of the anterior surface of the distal femur?
trochlear groove
articulation with patella
What are the parts of the posterior surface of the distal femur?
intercondylar notch (fossa or tunnel)
What is the patella?
triangular-shaped sesamoid bone
base of patella
quadricep tendon
apex of patella
patellar ligament to tibular tuberosity
1/2” proximal to tibiofemoral joint space
2 articular facets of the patella
form the PF joint
what does the patella articulate with?
trochlear groove
what is the bony pelvis?
2 hip bones
sacrum
coccyx
what is the purpose of the pelvis?
connects lower extremity to the axial skeleton
protects reproductive organs, lower GI tract, bladder
provides a strong support for the trunk
What makes up the hip bone?
Illium
ischium
pubis
1/2 the bony pelvis
What are the arts of the Illium?
Ala
Body
Medial surface
What is the Ala?
Broad curved portion
superior part
3 prominent border
Anterior
- ASIS
- AIIS
Posterior
- PSIS
- PIIS
- Greater Sciatic Notch
Superior
- Iliac crest
What is immediately posterior to the SI joint?
PSIS
What is the body of the Ilium?
Inferior part of the ilium
Forms superior portion of acetabulum (40%)
What is the medial surface of the Ilium?
Iliac Fossa
Auricular Surface
- SI joint
Arcuate Line
- separates Ala from body
- forms part of pelvic brim
- extends from auricular surface to pubis
What is the Ischium?
Inferior, posterior
Consists of body and ischial ramus
What is the body of the ischium?
forms posterior part of acetabulum (40%)
ischial spine
Lesser sciatic notch
ischial tuberosity
- the part we sit on
What is the ischial ramus?
projects anteriorly and medially and connects to the inferior pubic ramus
What are the parts of the pubis?
superior pubic ramus
body
inferior pubic ramus
What is the superior pubic ramus?
forms anterior part of acetabulum (20%)
What is the body of the pubis?
inferior and superior rami join
pubic crest
pubic tubercle
- pectineal line - travels along superior pubic ramus and meets arcuate line of ilium
What is the inferior pubic ramus?
connects to the ischial ramus
pubic arch
What is the obturator foramen?
opening formed between the pubic bones and ischial bones
allows nerves and blood vessels to pass through
What happens to the Ala in RPO position?
right Ala will appear wider than the left
What is the pubic arch?
opening formed between inferior pubic rami
Males < 90 degrees
Females > 90 degrees
What is a judet view?
for fractures of the acetabulum
Iliopubic column - anterior
ilioischial column - posterior
What is the pelvic brim?
boundary line that seperates the true pelvis from the false pelvis
non-bony part - superior part of pubic symphysis
what are the bony parts of the pelvic brim?
Sacral promontory
Arcuate lines of ilium
pectineal lines of pubis
superior part of the superior pubic ramus
What is the false pelvis?
also known as the greater pelvis
superior to pelvic brim
What does the false pelvis contain?
superior part of bladder when full
lower intestines
uterus
ovaries
fallopian tubes in females
What is the false pelvis bounded by?
lumbar spine
ala
anterior abdominal wall
What is the true pelvis?
also known as the lesser pelvis
inferior to pelvic brim
has an inlet and outlet
what is the true pelvis bounded by?
sacrum
coccyx
body of ilium
ischium
pubic bones
What does the true pelvis contain?
rectum
bladder
prostate
vagina
cervix
What is the inlet of the true pelvis?
entrance into the true pelvis
follow the pelvic brim
sacral promontory to superior pubic symphysis
arcuate lines (laterally)
What is the outlet of the true pelvis?
inferior opening of true pelvis
Tip of coccyx to inferior margin of pubic symphysis
between ischial tuberosities (laterally)
What angle is used for an inlet view?
40 degrees caudad
What angle is used for an outlet view?
30 degrees cephalad
What is the difference between male and female pelvis?
generally, bones of males are larger and heavier
adaptations to the female pelvis requirement for pregnancy and childbirth
females have a larger pelvic inlet and outlet
females have a shallow false pelvis whereas males have a deep false pelvis
Acetabulum formed by?
body of ischium and body of ilium but not the body of the pubis
