A7 - Lower Extremity

- AP pelvis

- Frog-leg pelvis

State the standard bilateral pelvis projections

AP pelvis

ID standard bilateral pelvis projection

Frog-leg pelvis

ID standard bilateral pelvis projection

No

Are there any supplementary bilateral pelvis projections?

Pubic symphysis

ID 1

Left femoroacetabular joint

ID 2 (joint)

Left posterior sacroiliac joint

ID 3 (joint)

Left anterior sacroiliac joint

ID 4 (joint)

Right: gluteus medius

Left: gluteal fat stripe

ID 5

- AP hip

- Frog-leg (lateral) hip

State the standard unilateral hip projections

Unilateral AP hip

ID standard unilateral hip projection

Frog-leg (lateral) hip

ID standard unilateral hip projection

No

Are there any supplementary unilateral hip projections?

- Femoral head

- Femoral neck

State the parts of the hip that are intracapsular

Femoral head

ID anatomy

Subcapital

ID anatomy

Mid-cervical

ID anatomy

Basicervical

ID anatomy

Appearance of lesions and their ability to heal is different when intracapsular

Importance of intracapsular hip

No - growth plate in a child

Broken?

No - growth plate in a child

Broken?

AP hip

View on left?

Frog-leg hip

View on right?

0

Risser's Classification Stage _____: no ossification center at the level of iliac crest apophysis

1

Risser's Classification Stage _____: apophysis under 25% of the iliac crest

2

Risser's Classification Stage _____: apophysis over 25-50% of the iliac crest

3

Risser's Classification Stage _____: •apophysis over 50-75% of the iliac crest

4

Risser's Classification Stage _____: apophysis over >75% of the iliac crest

5

Risser's Classification Stage _____: complete ossification and fusion of the iliac crest apophysis

Ischial apophysis

ID

Ischiopubic synchondrosis

ID

Wards triangle

An area that appears more radiolucent because it is surrounded by an abundance of trabeculae. The 1˚ and 2˚ compressive and tensile groups of the proximal femur leave a small region to appear more lucent

Osteopenia

Wards triangle becomes enlarged as bone density reduces, signifying _____

Normal vascular channel

ID

Kohler's teardrop distance

ID measurement line

- AP pelvis

- AP hip

What views are needed to see Kohler's teardrop distance?

- Medial margin of femoral head

- Lateral border of teardrop

Kohler's teardrop distance landmarks

6-11 mm

Normal Kohler's teardrop distance measurement

2 mm

The normal Kohler's teardrop distance is 6-11 mm, and there should be no greater than a _____ difference when comparing to the contralateral side

Hip joint effusion

Clinical significance of an enlarged Kohler's teardrop distance

Waldenstrom's sign

What sign indicates an enlarged Kohler's teardrop distance?

- Accentutation of the normal limits

Intracapsular swelling/joint effusion

Waldenstrom's sign is usually an indication of _____

Inflammatory arthritis

Clinical significance of a small Kohler's teardrop distance

Hip joint space width

ID measurement

Superior, axial, medial joint spaces (SAM)

Hip joint space width landmarks

3-6 mm

Normal superior hip joint space width

3-7 mm

Normal axial hip joint space width

4-13 mm

Normal medial hip joint space width

Joint effusion

Clinical significance of a wide hip joint space

Arthritis

Clinical significance of a narrow hip joint space

Symphysis pubis width

ID measurement

AP pelvis

What view is used to see the symphysis pubis width?

Distance between opposing articular surfaces

Symphysis pubis width landmarks

8 mm

Maximum symphysis pubis width measurement in adults

10 mm

Maximum symphysis pubis width measurement in children

Pregnancy/postpartum

The symphysis pubis width may be larger in _____

Diastasis

Clinical significance of a widened symphysis pubis

Shenton's line

ID measurement

- AP hip

- AP pelvis

What views are used to see Shenton's line?

- Smooth arc along femoral neck

- Obturator foramen

Shenton's line landmarks

Continuous and smooth

Shenton's line normal measurements

- Hip dislocation

- Femoral neck fracture

- Slipped epiphysis

Clinical significance of Shenton's line

Femoral angle

ID measurement

- AP pelvis

- AP hip

What views are used to measure the femoral angle?

- Mid-axis of femoral shaft

- Mid-axis of femoral neck

- Intervening angle

Femoral angle landmarks

120-130˚

Normal femoral angle measurement

Coxa vara

Femoral angle <120˚

Coxa valga

Femoral angle >130˚

Skinner's line

ID measurement

- AP hip

- AP pelvis

What views are used to see Skinner's line?

- Mid-axis of femoral shaft

- Right angle tangent to tip of greater trochanter

Skinner's line landmarks

Fovea capitis should lie above or at level of trochanteric line

Skinner's line normal measurement

Fracture or other causes of coxa vara

Clinical significance of Skinner's line

Klein's line

ID measurement

- AP pelvis

- AP hip

What views are used to see Klein's line?

Line along femoral neck

Klein's line landmarks

Line should intersect portion of femoral head

Klein's line normal measurement

Slipped capital femoral epiphysis

Clinical significance of Klein's line

Growth plate

A slipped capital femoral epiphysis is a _____ fracture

- AP knee

- Lateral knee

- Tunnel (intercondylar) knee

State the standard knee projections

AP knee

ID standard knee projection

Lateral knee

ID standard knee projection

Flexion

Lateral knee projections are generally taken with _____

Tunnel (intercondylar) knee

ID standard knee projection

- Sunrise (tangential) knee

- Internal oblique knee

- External oblique knee

State the supplementary knee projections

Sunrise (tangential) knee

ID supplementary knee projection

Patellofemoral joints

Sunrise knee projections help see the _____

Medial patellofemoral joint

ID 37 (joint)

Lateral patellofemoral joint

ID 38 (joint)

Odd facet

ID 39

Infrapatellar pouch

ID 29

Hoffa's fat pad

Another term for infrapatellar pouch

Quadriceps tendon

ID 30

Prefemoral fat pad

ID 31

Suprapatellar pouch

ID 32

Lateral tibiofemoral joint

ID 33 (joint)

Proximal tibiofibular joint

ID 34 (joint)

Medial tibiofemoral joint

ID 35 (joint)

Patellofemoral joint

ID 36 (joint)

Ludloff's patch/spot

- Not a true anatomical structure

- Appears due to less bone being traversed anteriorly than posteriorly