Hip Flashcards
Angle of inclination
-angle between head and shaft of femur
coxa vara <120 deg
normal 120-135 deg
coxa valga > 135 deg
Hip ligaments
iliofemoral ligament- from AIIS to intertrochanteric line. Taut in extension. promotes stabilization in erect posture.
pubofemoral ligament- from inf acetabular rim to inf femoral neck. Helps limit abd and ext
ischiofemoral- ischial portion of acetabulum to fem neck. Prevents excessive ext and IR of hip jt
Children pathologies
transient synovitis
legg-calve-perthes (avoid weight bearing-avascular necrosis)
juvenile rheumatoid arthritis
septic arthritis, septic bursitis, osetomyelitis
Teenager pathologies
Slipped capital femoral epiphysis
Snapping hip syndrome
Femorofacetabular impingement (use arthrogram for impinge)
Adult pathologies
osteoarthritis
osteoporosis
Routine radiographs of pelvis/hip
pelvis- AP projections which shw entire pelvis, sacrum, coccyx, and lumbosacral articulations, and bilateral hip joints.
unilateral hip- AP and lateral frog leg
AP pelvic projection
used for: bilateral comparison of hip joints, identify trauma, and identify need for unilateral hip radiograph.
Can show fracture, dislocation, or pathology
Look for: ABCs
AP hip projection
hip jt, lesser trochanter, cortical margins of femoral shaft (bone density-looking for stressed areas)
normal ball and socket configuration seen
can see avascular necrosis, RA, DJD, and destructive tumors
Lateral from leg
view: hip positioned in flx, ER, and lateral abd
the lesser trochanter is now seen in profile
Basic MRI indications for the hip
osteonecrosis of fem head, MARROW abnormalities, fractures, childhood hip disorders and their adult sequelae, FAI, acetabular labral tears, musculotendinous disorders and assoc bursitis, athletic pubalgia, osteochondral anormalities, sacral plexus abnormalities
T1- weighted sequence to define anatomy (darker)
T2-weight sequence to detect abnormal fluid and thus highlight pathology (white)
ABCDs
Basic CT protocol for the hip
assessment of severe trauma, assess alignment and displacement of fracture fragments, identify loose bodies in jt, eval fractures of acetabulum or sacrum, eval bone alignment, eval any condition contraindicated by MRI
axial slices, sagittal and coronal places
ABCs
MSUS indications of the hip
detect soft tissue injury, visualize capsule/synovium, and bursa, define ligament/muscle/or tenson, eval soft tissue massses, identify loose intra-articular bodies, differentiate effusion, guide needle, eval anormalities
Fracture of proximal femur
Can occur from osteoporosis and falls
Radiographs with AP and lateral views most appropriate. MRI can be used for stress fractures.
Hip dislocation
Can occur from falls, trauma, MVA
90% occur posteriorly
AP pelvic radiographs most appropriate. Post hip dislocations the fem head appear smaller.
CT scans can be obtained after closed reduction to assess the femoral head and congruency
Degenerative joint disease (osteoarthritis)
Pain and loss of motion
Radiograph findings: jt space narrowing, sclerotic subcondral bone, osteophyte formation of jt margins, cyst or pseudocyst formation, and migration of fem head
Rheumatoid arthritis of the hip
radiographs and MRI for more detailed imaging
deminerzliazation of femoral head, jt space narrowing, axial migration of fem head into acetabulum, and articular loss of ball and socket jt configuration
Avascular necrosis of proximal femur
Interruption of blood supply to the femoral head, causing bone tissue death
Can be associated with femoral neck fractures posttraumatically
AVN is expressed as Legg-Calve_perhtes disease
LCP is common in young boys (avg 6 yrs)
Radiographs may appear normal in initial stages. Advanced stages show collapsed femoral head from structural weakness and inability to withstand weight bearing.
MRI most appropriate for early SENS and SPEC in diagnosing AVN
Slipped Capital Femoral Epiphysis (SCFE)
Postero-medio-inferior displacement of the proximal femoral epiphysis.
Childhood and adolescence
Radiographs will show the amount of slippage present
AP projection shows burring and widening of the physis and dec height of epiphysis relative to contralateral hip
Lateral frog leg projection shows amount of epiphyseal displacement
Development of Hip dysplasia (DDH)
malformation of the hip found a birth or younger children beginning to walk
Usually affects the left hip of girls most often
MRI or ultrasound very vaulable for DDH in infant. Deformation of the acetaulum and femoral head can be well visualized prior to ossificiation
Femoral acetabular impinegment
abutment of the femoral head with the acetabulum
Cam (fem head-neck junction) and pincer (overcoverage of fem head by acetabulum(
Pelvic and hip radiographs assessed first
MR arthrography is used to assess labral tears
