LEA - Osteology Flashcards
name the vertebral structure that matches with its corrsesponding fused sacral structure
what is the difference between the pelvic girdle and the bony pelvis?
- pelvic girdle: ilium, ischium, & pubis
- bony pelvis: pelvic girdle + sacrum & coccyx
the pelvic girdle and its components are part of the the appendicular skeleton, while the sacrum and coccyx are part of the axial skeleton
which pelvic bone is the FIRST to fuse?
pubis (8 years)
- followed by the ilium (16-23 years) and ischium (17-25 years).*
- Remember to reveiw ossification charts and commit to memory!*
the iliopectineal line is made by which two bony landmarks?
pectin pubis (pubis) & arcuate line (ilium)
Add on the sacral promontory and you have the “linea terminalis”
which bone contains the anterior, posterior, and inferior gluteal lines?
ilium
these lines mark the areas of origin of the gluteal muscles:
- gluteus maximus - posterior to the posterior gluteal line
- gluteus medius - between the posterior and anterior gluteal lines
- gluteus minimus - between the anterior and inferior gluteal lines
what parts of what bones make up the acetabulum of the pelvis?
- body of ilium
- body of ischium
- superior ramus of the pubis
what ligament attaches to the pubic tubercle?
the inguinal (aka Pourpart’s) ligament
- this important ligament runs from the anterior superior iliac spine (ASIS) to the pubic tubercle.*
- Review the important structures that pass beneath inguinal ligament, or see in landmarks section*
what bones form the obturator foramen?
pubis & ischium
the obturator nerve, artery, and vein traverse this foramen to exit the pelvis
what area of the ischial tuberosity is devoid of muscular origin?
sitz platz
- this is part of the tuberosity that is exposed when sitting. It is located on the inferomedial aspect of the tuberosity.*
- Refer to card #184 in landmarks for more info. on muscular origins from the ischial tuberosity*
name the order in which the secondary ossification centers of the femur begin to ossify and then fuse
what is the femoral angle of inclination?
also known as the “Q” angle, it is made by the longitudinal axis of the femoral shaft and a line perpendicular to the ground.
Normal is 10-15 degrees in adults
what is the femoral angle of torsion (declination)?
angle made by the longitudinal axis of the femoral neck and the femoral condyles in the frontal plane.
normal is 10-15 degrees in adults (higher in children)
what lines contribute to the formation of the linea aspera?
- medial lip: spiral line + pectineal line
- lateral lip: gluteal tuberosity
The linea aspera comprises the posterior border of the femoral shaft that divides its medial and lateral surfaces. It terminates as the medial and lateral supracondylar ridges at the distal shaft to create the triangular popliteal surface
what is the inherently weak portion of the femoral neck called?
ward’s triangle;
(aka the internal femoral triangle)
name the muscles that insert into the bony structures on the proximal femur
where is the adductor tubercle of the femur located?
at the termination of the medial supracondylar ridge on the posterior aspect of the femoral shaft
it serves as the insertion for the adductor portion of the adductor magnus muscle
how do you “side” a patella?
the lateral facet on the posterior surface will be larger than the medial facet, which can help you determine if it came from the left or the right lower extremity
the patella is the largest sesamoid in the body; it acts as a fulcrum for the quadriceps tendon during extension. It ossifies at 3-6 years of age
when does the primary center of ossification appear for the long bones of the thigh and leg?
femur: week 7 of gestation
tibia: week 7-8 of gestation
fibular: weeks 8-9 of gestation
* for all 3, the primary center is located in the DIAPHYSIS*
describe the order of appearance of the secondary ossification centers in the leg
- proximal tibial epiphysis: birth
- distal tibial epiphysis: 3-10 months old
- distal fibular epiphysis: 9-22 months old
- proximal fibular epiphysis: 3-5 yrs old
Trick: Proximal to distal, distal to proximal with the tibia coming first
what is the angle used to describe in-toeing of the foot due to the tibia?
tibial torsion,
- this angle is made by two lines in the transverse plane. One is made from medial to lateral across the tibial plateau. The other connects the malleoli*
- as an infant, tibial torsion causes the foot to take on an in-toed appearance. this angle increases trhoughout development, moving away from the in-toed position to a more neutral or even out-toed one*
what inserts into Gerdy’s tubercle?
iliotibial (IT) band
- the tensor fascia lata and gluteus maximus insert into the IT band.*
- Gerdy’s tubercle is located at the lateral condyle of the tibia anteriorly*
what parts of the tibia and fibula are subcutaneous?
- tibia: anterior border (shin), medial surface (no muscular attachments), medial malleolus
- fibula: head of the fibula, distal triangular part of anterior border, lateral malleolus
Since these structures are subcutaneous, they are also palpable
the tendons of what muscles travel in the medial and lateral malleolar sulci?
name the bones that make up the medial longitudinal arch of the foot
