6. Appendicular Skeleton-Lower extremity Flashcards
How many bones are there in the foot?
26
What are the 3 divisions of the foot? What bones are part of each division?
- Forefoot: Toes and metatarsals
- Midfoot: Cuneiforms, navicular, cuboid
- Hindfoot: Calcaneus and talus
What are the 7 tarsal bones?
- Medial cuneiform
- Intermediate cuneiform
- Lateral cuneiform
- Navicular
- Cuboid
- Talus
- Calcaneus
Where are the sesamoids located on the hallux
Posterior to the head of the metatarsal
What causes bunions?
Hallux valgus deformity
What are the 3 parts of the talus?
- Head
- Neck
- Talar Domes
What type of joint is the talus head?
Ball and socket
What do the talar domes articulate with?
The tibia and fibula
Label foot landmarks and joints
Just do this and then your done your studying for today
What is the sulcus tali on the inferior talus?
The groove that forms the roof of the sinus tarsi that is inferior to the neck
What are the 3 articular facets of the talus?
- Anterior
- Middle
- Posterior
What type of joint does the talus and calcaneus facets make?
The Subtalar joint
What is the calcaneal sulcus?
The groove (faucet) that forms the floor of the sinus tarsi
What is located in the medial calcaneus?
Sustentaculum tali
What are the 4 joints of the talus?
- Tibiotalar joint
- Fibulotalar joint
- Subtalar joint (talocalcaneal)
- Talonavicular joint
What are the 5 joints of the calcaneus?
- Subtalar joints (3 joints a,m,p)
- Calcaneonavicular joint
- Calcaneocuboid joint
What are the facets of the calcaneus?
- Anterior
- Middle
- Posterior
- Calcaneal sulcus
What are the joints of the navicular?
- Calcaneonavicular joint (tarsal coalition)
- Talonavicular joint
- Navicular cuboid joint
What are the joints of the cuboid?
- Calcaneocuboid joint
- Joint between cuboid and lateral cuneiform
- Joint between cuboid and navicular
- TMT joint
What does the TMT joint articulate with?
Cuboid, m+L+i cunieforms
What are the joints of the cuneiforms?
- Medial cuneiform-TMT joint with great toe
- Intermediate cuneiform-TMT joint with 2nd toe
- Lateral cuneiform-TMT joint with 3rd toe
What is the function of the longitudinal arches?
Functions as a shock absorber and provides leverage while walking
What are the longitudinal arches formed and strengthened by?
-Formed by the tarsals and metatarsals
-Strengthened by ligaments and tendons
What are the 2 longitudinal arches and where do they travel through?
- Medial: Originates at calcaneus, rises to the talus and descends at the heads of the first 3 metatarsals
- Lateral: Originates at the calcaneus, rises to cuboid and descends at the heads of the lateral 2 metatarsals
What bones is the transverse arch formed by?
-The 3 cuneiforms
-Cuboid
-Bases of 5 metatarsals
Which of the leg bones is the larger, medial, weight-bearing bone
The Tibia
Between the tibia and the fibula, which is the more posterior bone?
The Fibula
What three things help to support the knee?
Menisci, MLC, LCL
How much of the fibular head should be superimposed by the lateral condyle?
1/2 of fibular head
Which way does the tibial plateau slide?
Posteriorly
What are the characteristics of the two tibial condyles?
- Medial condyle:
-Curved from anterior to posterior - Lateral condyle
-Straight from anterior to posterior
-Facet on posterolateral surface where fibular head articulates
What separates the two condyles?
Intercondylar Eminences or tibial spines separate the condyles
How much does the prox tibia slide posteriorly
Slopes 5 degrees posteriorly
What happens when the menisci when they wear down?
You develop Osteoarthrosis
What type of bone is the tibial tuberosity and what ligament attaches to it?
An apophysis, the patellar ligament attaches to it
What side is the fibular notch on and what does it articulate with?
The lateral side and articulates with the distal fibula
What overlays the proximal fibula?
The Anterior Tubercle
What is the Ankle Mortise?
Refers to the bony arch or joint formed between the tibial plafond and malleoli
What type of projection images the Ankle Mortise?
The Mortise projection
What forms the lateral malleolus?
The Tibia
What forms the medial malleolus?
The Tibia
What landmarks are part of the distal tibia?
Medial malleolus and posterior malleolus
What does the proximal part of the fibula articulate with and what joint does it create?
Articulates with lateral condyle of tibia and creates the Proximal Tib/Fib Joint
How do you image the distal fibula and why?
45 degrees internally obliqued because the Lateral malleolus is 15-20 degrees more posterior compared to the medial malleolus
What joins the trochanters anteriorly?
The Intertrochanteric line
What is the ridge of bone between the trochanters posteriorly?
Intertrochanteric crest
What is the ridge of bone on the posterior femur that is a site for muscle attachment?
Linea aspera
What is on the head of the femur?
The fovea Capitis
Which way does the neck of the femur slope?
Slopes 15 to 20 degrees posteriorly from pelvis
How do you prevent foreshortening of the femoral neck
In an AP pelvis
Internal rotation of legs for AP pelvis
Where is the greater trochanter?
Posterior lateral
At the tip of the coccyx
Where is the lesser trochanter on an AP?
On a true AP pelvis, it will be posterior to femur
(Medial side of the femoral neck)
How do you image a cross table lateral of the femur and why?
Come in on a 45-degree angle to the femur-this will bring you perpendicular to your femoral neck
What landmarks are on the medial femoral condyle?
Adductor tubercle and medial epicondyle
Where is the adductor tubercle?
Posteromedial aspect of the distal femur
What 2 things are on the ant. lateral condyle of the femur?
Lateral epicondyle
Sulcus terminalis
How are the medial and lateral condyles distally positioned to each other?
Medial condyle is 5 to 7 degrees more distal compared to the lateral condyle
How do you angle a mediolateral knee?
5 to 7 degrees cephalad for a mediolateral knee
What is on the ant surface of the distal femur and what does it articulate with?
Trochlear groove and articulates with the patella
What is on the posterior side of the femur?
(distal)
Intercondylar Notch/fossa/tunnel
What is the purpose of the Intercondylar Notch/fossa/tunnel?
A place for ACL and PCL to get across
What is on the base of the pattella?
Quadricep tendon
What is on the apex of the patella and how is it positioned to the tibiofemoral joint?
Patellar ligament
½” or 1.25 cm proximal to tibiofemoral joint space
What are the 3 main bones of the pelvis?
Ilium
Ischium
Pubis
What is the purpose of the pelvic bones?
-Connects lower extremity to the axial skeleton
-Protects reproductive organs, lower GI tract, bladder
-Provides a strong support for the trunk
What is on the ant surface of the illium?
ASIS
AIIS
What is on the posterior aspect of the ilium?
PSIS
PIIS
Greater Sciatic Notch
Sciatic nerve
What forms the superior portion (40% of acetabulum)
The ilium
What is the arcuate line’s purpose?
-Separates ala from body
-Forms part of the pelvic brim
-Extends from auricular surface to pubis
What forms the 40% of the posterior acetabulum?
The ischium
Where is the intertrochanter line?
JOins the trochanters anteriorly
How do you get rid of foreshortening of the illium?
for AP
Internally rotate the feet 15-20 degrees
What makes up the body of the pubis?
-The inferior and superior rami join
-The pubic crest
-The pubic tubercle
Where does the pectineal line travel?
Along the sup. pubic ramus and meets the arcuate line of illium
What does the inf. pubic ramus connect to?
The ischial ramus and pubic arch
What is the view called for the acetabulum and how do you image for this?
Judet-Oblique the pelvis 45 degrees
What is the pelvic brim?
The boundary line that separates the true pelvis from the false pelvis
Where is the true and false pelvis?
False: Sup. to pelvic brim
True: Inferior to pelvic brim and has an inlet and outlet
What is the inlet view?
The entrance to the the true pelvis and follows the pelvic brim
What is the outlet view?
How do you measure AP
Inferior opening of the true pelvis-from tip of coccyx to inf margin of pub. symph.
How do you image the inlet view and what determines the width?
Angle the tube caudad, and the 2 arcuate lines determine the width
How do you image the outlet view?
15-30 degrees cephalad
How do you measure the pelvic inlet?
AP: Sacral prominatroy to pubic crest
Horizontally: Between arcuate lines
How do you measure the pelvic outlet?
AP: Tip of coccyx to pubic symphysis
Horizontally: Ishial tuberosities
