MODULE 7

HIP

HIP: NORMAL ANATOMY AND POSITIONING

Three views• AP• Lateral• Frog Leg

LINES OF MENSURATION

Teardrop distance Maximum of 11.0mm, minimum of 6.0mm,

with an average of 9.0mm Waldenstrom sign

Fig 3-48A

Teardrop distance

Fig 3-48A

Increased Teardrop distance

LINES OF MENSURATION

Hip joint space width Three measurements

• superior• axial• medial (aka - teardrop)

Pattern of collapse is very important to note

Hip joint space width

LINES OF MENSURATION

Acetabular Depth <7.0mm in males and 9.0mm in females Dysplasia has an intact joint space Rheumatoid arthritis has a loss in joint

space

Acetabular Depth

Fig 3.50a

LINES OF MENSURATION

Center-edge angle Represents “coverage” of femur head by

acetabulum Minimum of 20o, maximum of 40o, with an

average of 36o

Center-edge angle

Fig 3.51a

LINES OF MENSURATION

Symphysis Pubis Width Increased width is indicative of

cleidocranial dysplasia, bladder exostrophy, HPT, trauma - diastasis, osteolysis - ankylosing spondylitis, osteopubis, gout

Symphysis Pubis Width

Fig 3.52a

Symphysis Pubis Width

Fig 3.52b

LINES OF MENSURATION

Acetabulur angle Minimum 12o, maximum 29o, with an

average of 20o

Increased angle is indicative of dysplasia, congenital hip dislocation

Decreased angle is indicative of Down’s syndrome

Acetabulur angle

Fig 3.54

LINES OF MENSURATION

Protrusio acetabuli (Kohler’s line) Femur head should be lateral If acetabulum floor crosses line - idiopathic,

rheumatoid arthritis, Paget’s (osteomalacia)

Kohler’s line

Fig 3.57b