Femur Flashcards
Proximal extremity contains 6 structures
- Head
- Neck
- Greater trochanter
- Lesser trochanter
- Intertrochanteric line
- Intertrochanteric crest
Head of femur
- Ball shaped for articulation with hip bone at acetabulum
- 2/3 of structure is spherical and is covered by hyaline cartilage (except fovea “pit”)
- Fovea is the site of attachment for the ligament of the head of the femur
- The entire head structure lies in the articular capsule of the hip joint
Neck of femur
- Joins head and shaft of bone
- This creates a femoral angle of inclination
- This angle is greatest at the time of birth
- Sex and body size determine the angle
Normal adult values for femoral angle of inclination
- Male = 125 degrees
- Female = 105 degrees
Angle of declination
- The anterior projection of the neck from the shaft of the femur creates the angle of declination
- The normal value for this is 12 - 14 degrees
Shape and surfaces of neck of femur
- Hour glass shaped (thinnest in middle)
- Two surfaces: anterior and posterior
Anterior surface of neck of femur
- Entirely enclosed in joint capsule of hip joint
- Covex superior to inferior
- Concave side to side
- Many small vascular foramina
- Intertrochanteric line
Intertrochanteric line
- Between greater and lesser trochanters on the anterior surface of neck of femur
- Continuous inferiorly with the spiral line
Posterior surface of neck of femur
- More curved than anterior surface
- Upper 1/2 to 2/3 lies in the joint capsule
- The lower portion is grooved for the tendon of obturator externus
- There are fewer but larger vascular foramina when compared to the anterior surface
- Intertrochanteric crest
Intertrochanteric crest
- Ridge of bone between greater and lesser trochanters
- Where the posterior neck joins the shaft of the femur
Superior border of neck of femur
- Short, thick, courses horizontally
- Ends at greater trochanter
Inferior border of neck of femur
- Long, thin, courses vertically
- Ends at lesser trochanter
Greater trochanter
- Large, irregular, quadrilateral-shaped prominence
- Located at the lateral end of the superior border of the neck of the femur
- Projects laterally and posteriorly
- Contains two surfaces: lateral and medial
Lateral surface of greater trochanter
- Larger, palpable, quadrilateral shaped
- Contains an oblique bony ridge for insertion of the gluteus medius
- Bony ridge divides the lateral surface into two triangular areas, each covered by a trochanteric bursae
- Upper triangle has a bursa for the gluteus medius
- Lower triangle has a bursa for the gluteus maximus
Medial surface of greater trochanter
- Trochanteric fossa is the major feature - a depression for insertion of obturator externus
- The obturator internus tendon inserts on the anterior surface of the trochanteric fossa
- NOTE: the superior and inferior gemelli muscles terminate and insert into the tendon of obturator internus
4 borders of greater trochanter
- Superior
- Inferior
- Anterior
- Posterior
Contain muscle attachment sites
Muscle attachment to superior border of greater trochanter
- Piriformis muscle insertion
Muscle attachment to anterior border of greater trochanter
- Insertion of gluteus minimus
Muscle attachment to inferior border of greater trochanter
Partial origin of vastus lateralis
Muscle attachment to posterior border of greater trochanter
- ONLY border with NO muscular attachments
- Free rounded edge inferiorly, which blends with the intertrochanteric crest
Lesser trochanter
- Located medially, near the junction of the femoral neck and shaft
- Directed posteromedially
Muscle attachments for lesser trochanter (3)
- Attachment site for iliopsoas muscle (ONLY attachment site for this muscle, which is a major flexor at the hip)
- Psoas major inserts at the apex
- Iliacus inserts at the base of the lesser trochanter, between the spiral and pectineal lines
Intertrochanteric line
- Anterior line
- Located between greater and lesser trochanters at junction of neck and shaft
3 attachments to intertrochanteric line
- Iliofemoral ligament (part of fibrous capsule of hip)
- Vastus lateralis (partial origin)
- Vastus medialis (partial origin)
Intertrochanteric crest
- POSTERIOR crest
- Located between greater and lesser trochanters
- Hip joint capsule is NOT attached here
- Contains quadrate tubercle
Quadrate tubercle
- Located at mid-intertrochanteric area
- Site of insertion of quadratus femoris
- Sometimes quadrate line is present (instead of tubercle)
- Quadrate tubercle/line extends vertically (straight up) 5 cm with the superior extent located along the intertrochanteric crest
Shaft of femur
3 borders
- Medial
- Lateral
- Posterior
3 surfaces
- Medial
- Lateral
- Anterior
Medial and lateral borders
- Both borders are rough and poorly defined
Posterior border major feature
Linea aspera (“rough line”)
Linea aspera
- A crest that is located along the posterior border of the middle 1/3 of femur
- This crest has 2 lips (medial and lateral lips) with a rough area in between (intermediate
- Superiorly, 3 lines joint to form linea aspera
3 lines that join to form linea aspera
- Spiral line
- Pectineal line
- Lateral line
Spiral line
- Medial line from intertrochanter line
- Continuous with linea aspera
Pectineal line
- Intermediate line from lesser trochanter
- Continuous with medial lip
Lateral line
- Lateral line from greater trochanter
- Continuous with lateral lip
- Extends almost vertically
- Gluteal tuberosity is located here for partial insertion of gluteus maximus which also inserts on the IT band
Variation in gluteal tuberosity
- Often times the proximal portion of the gluteal tuberosity is elongated and enlarged
- It is then called the “third trochanter” or “gluteal trochanter”
Inferior landmarks
- Lateral lip and medial lip of linea aspera diverge as 2 ridges into the lateral and medial supracondylar ridges
Lateral supracondylar ridge
- More distinct
- Extends toward lateral epicondyle
Medial supracondylar ridge
- Ends at adductor tubercle
- Smooth, just proximal to adductor hiatus
- Adductor hiatus is where femoral vessels pass to popliteal fossa
Popliteal surface
- The two ridges (lateral and medial supracondylar ridges) form a triangular surface called the popliteal surface
Anterior surface of shaft of femur
- Smooth, convex surface
- Lies between medial and lateral borders
- Attachment site for 2 muscles
2 muscles that attach to anterior surface of shaft of femur
- Vastus intermedius (upper 2/3)
- Articularis genu
Articularis genu
- Femur may be roughened for several small slips of origin for this muscle
- This is the distal attachment (anterior surface of shaft of femur)
Distal extremity of femur
- Major features include medial and lateral femoral condyles
Lateral condyle
- Broader, more pronounced than medial condyle
Medial condyle
- Longer, starts at adductor tubercle
Femoral condyles (general)
- Both condyles articulate with the posterior patella and respective condyles of the tibia
- Both condyles are large, rounded, knob-like structures that project further posterior than anterior
Lateral and medial sulci menisci
- Groove (sulcus) located on each condyle
- This groove separates the patellar and tibial surfaces of the femoral condyles
Lateral sulci menisci
- Completely separates patellar surface of lateral femoral condyle from tibial surface
Medial sulcus menisci
- Deficient laterally (where tibial and patellar surfaces are continuous)
Posterior surface of femur
- Contains intercondylar notch
- Contains intercondylar line
Intercondylar notch
AKA intercondylar fossa
- Separates femoral condyles posteriorly
Intercondylar line
- Serves as posterior boundary of notch
- Forms base of popliteal surface of femur
Attachments to intercondylar line
- ACL attaches posteriorly to the medial surface of the lateral condyle
- PCL attaches anteriorly to lateral surface of medial condyle
- Meniscofemoral ligametns
Medial epicondyle
- Lies above the medial condyle and just below the adductor tubercle
- BOTH the adductor tubercle and medial epicondyle are palpable
Attachments to medial epicondyle and adductor tubercle
- Medial epicondyle is the attachment site for the tibial (medial) collateral ligament
- Adductor tubercle is the attachment site for the tendon of adductor magnus muscle
- Just posterior to the adductor tubercle is the attachment site for the gastrocnemius muscle
Lateral epicondyle
- Also palpable
- Attachment site for fibular (lateral) collateral ligament
- Lower portion has 2 grooves for the popliteus muscle
Popliteus tendon
NOTE - the popliteus tendon changes position based on teh position of the knee (flexed or extended)
- When the knee is FLEXED, the tendon is in the OBLIQUE groove
- When the knee is EXTENDED, the tendon is in the vertical groove
REMEMBER: FO - EVer
- Flexed = Oblique groove
- Extended = Vertical groove
Femoral arterial supply
- Extensive blood supply for the largest bone in the body
- Proximal, shaft and distal supply
Proximal supply
“FILM O femur”
- F = first perforating artery (enters at neck)
- I = inferior gluteal artery (enters at neck)
- L = lateral femoral circumflex (enters at neck)
- M = medial femoral circumflex (enters at neck)
- O = obturator artery
Medial femoral circumflex artery
- Branch of profunda femoris
- Major supply to femoral head in adults
Obturator artery
- A branch of teh obturator artery courses within the ligament of the head of the femur
- Supplies the femoral head
- Important in infants, children and teens during ossification of the femur
- Unimportant in adults because the medial femoral circumflex is the main supply
Femoral shaft arterial supply
- Nutrient artery from a branch of the second perforating artery
- Nutrient canal is located posteriorly along the upper end of the linea aspera and is directed obliquely upward (away from growing end of bone during development)
- NOTE: for ALL long bones, the nutrient canal is directed obliquely away from growth
Distal femoral arterial supply
- Superior lateral genicular artery
- Superior medial genicular artery
- Descending genicular artery
- Descending branch of lateral femoral circumflex
5 femoral ossification centers
- Primary
- 1st secondary
- 2nd secondary
- 3rd secondary
- 4th secondary
Primary femoral ossification center
- Located at the shaft
- Appears during the 7th fetal week
- Fuses at puberty
1st secondary femoral ossification center
- Located at distal extremity
- Appears around birth
- Fuses at 16-18 years
2nd secondary femoral ossification center
- Located at head
- Appears at 6 months
- Fuses at 17 years
3rd secondary femoral ossification center
- Located at greater trochanter
- Appears at 4 years
- Fuses at 16 years
4th secondary femoral ossification center
- Located at lesser trochanter
- Appears at 12-14 years
- Fuses at 15 years
Notes on ossification
- The femur ossifies via endochondral ossification
- The femur is the first bone to begin this type of ossification
- The femur is the second earliest bone to ossify
- Only the clavicle (which ossifies via an intramembranous method) begins to ossify earlier than the femur
- The appearance and fusion times for each secondary center are inversely related - the later it appears, the sooner it fuses
