Lab 6 Checkoff: Pelvis, Femur, Hip, and Patella

Pelvis AP Projection

Internal rotation of the foot 15-20 degrees if possible; do NOT attempt rotation if fx is present.

Pelvis CR Positioning

CR perpendicular to midway between ASIS and Symphysis Pubis @ Midsagittal Plane; 2 inches distal from ASIS / 2 inches superior from symphysis pubis.

Pelvis Film Size

14x17 Horizontal.

Pelvis Light Field Position

Top of light field should be 2 inches above iliac crest.

Pelvis Exposure Settings

80 @ 16.

Pelvis SID

40-inch SID.

Pelvis Grid Requirement

Grid.

Pelvis Anatomy Included

2 inches above the iliac crest, symphysis pubis, no rotation of iliac wings or obturator foramen.

*wings or foramen will appear larger on the side the patient is rotated towards

Femur AP Proximal

10x12 Vertical; internally rotate foot 15-20 degrees.

Femur AP CR for Distal

CR perpendicular to mid-shaft including 2 inches below the knee; internally rotate foot 5 degrees

Femur Film Size Distal

14x17 Vertical.

Femur Lateral Proximal

10x12 vertical.

Femur Lateral Distal Positioning

Flex knee approximately 45 degrees; CR perpendicular to mid-shaft; include 2 inches below the knee.

Femur Views Required

4 views on most adult patients: AP Proximal Femur (Hip), Frog Leg Proximal Femur (Hip), AP Distal Femur, and Lateral Distal Femur.

*2 films/views (AP & Lateral) on small children; use two 14x17 to include both joint spaces.

Femur Exposure Settings Distal

70 @ 16 for distal / 80 @ 16 for proximal hip.

Hip AP Positioning

2 inches medial from ASIS; 3-4 inches distal.

*CR perpendicular to femoral neck

Hip Light Field Position

Top of light field should be at ASIS.

Hip Exposure Settings

80 @ 16.

Hip Film Size

10x12 vertical.

Hip Anatomy for AP

Lesser trochanter should be superimposed behind the femur; reduces distortion & foreshortening of the femoral neck.

Common Signs of Hip Fx/Dislocation

Shortening of limb & external rotation of foot on the affected side.

Trauma Danielius-Miller method (cross table lateral)

Lateral Hip projection for surgery or possible fx (frog leg hip is not possible)

*CR -> mid-femoral shaft on unaffected side

*Tube angulation depends on patient's body habitus

*lift unaffected leg out of view

Patella AP Positioning

CR perpendicular to mid-patella.

Patella Lateral Positioning

CR perpendicular to patellofemoral articulation/joint space.

Patella Exposure Settings Grid

60 @ 8 for Grid.

Patella Exposure Settings Non-Grid

60 @ 3 for cross-table / non-grid.

Patella Film Size

10x12 vertical.

Patella SID

40 inch SID.

Reason for AP over PA Patella

AP patella is performed most commonly for patient comfort, but PA is preferred for a true diagnostic image (book perfect image).

*AP - increased OID (more distortion & increased magnification)

*PA - Decreased OID (less distortion & true size/less magnification)