Hip Flashcards
routine view of the pelvis
AP
typically includes both proximal femurs
AP view should notice:
Symmetrical appearance:
- pelvic halves
- obturator foramen
- acetabular depth
- cartilage thickness
- femoral head shape
- rotation of femurs
Alignment:
- pubic symphysis
- SI joints
AP view outline:
L5
Pelvis
- bones of the coccyx
- SI joint
- sacrum, sacral forament
- PSIS, ASIS, AIIS
- sciatic notch
- acetabulum (roof, ant and post rims)
- pubic symphysis
- sup and inf pubic ramus
- radiographic teardrop
- obturator foramen
Proximal femur
- head
- neck
- greater trochanter
- lesser trochanter
- angle of inclination
routine unilateral view of the hip
AP view
what to notice in unliateral AP view of hip
- spherical femoral head
- thickness of cartilage (radiologic joint space)
- bone density
- osteophytes?
- Shenton’s hip line
- iliofemoral line
- femoral neck angle (normal=125-135 deg)
unilateral AP view of the hip outline
Pelvis:
- sacrum
- obturator foramen
- ischial tuberosity
- acetabulum (sup, ant, post rims)
- radiographic teardrop
Femur:
- head
- neck
- greater trochanter
- lesser trochanter
- intertrochanteric crest
- angle of inclination
Uni-lateral frog leg
routine view
- femur is now viewed medial to lateral because of rotated position
- better view for lesser trochanter
what to notice in unilateral frog-leg?
- spherical femoral head
- thickness of cartilage
- bone density
- osteophytes?
outline unilateral frog-leg
Pelvis:
- sacrum
- obturator foramen
- ischial tuberosity
- acetabulum (sup, ant, post rims)
- radiographic teardrop
Femur:
- head
- neck
- greater trochanter
- lesser trochanter
- intertrochanteric crest
oblique views
??
AP shows fractures around the acetabulum but bc of overriding it is difficult to determine where the fx is.
oblique views can better show the ilioischial and iliopubic bridges and the ant/post rims of the acetabular rim
stable pelvic fractures
don’t disrupt any of the joint articulations
Include:
- avulsion fractures of the ASIS, AIIS< or ischial tuberosity (typically seen in athletes-forceful/repetitive ms contractions)
- iliac wing fracture
- sacral fracture
- ischiopubic ramus fractures (at most 1 fx through the pelvic ring)
dashboard fractures
knee strikes the dashboard in a collision resulting in forces transmitted up the femur and into the acetabulum
unstable fractures
frequently associated w/ internal hemorrhage and life threatening
includes:
- at least 2 or more fractures through the pelvic ring (can include dislocated SI joint)
- vertical shear or malgaigne fractures
- straddle fractures (all 4 ischiopubic rami)
- bucket handle fractures (ischial and ipsilateral pubic ramus, and contralateral SI)
treatment for unstable pelvic fractures
internal fixations: compression screws/plates
external fixations
treatment for stable pelvic fractures
brief period of bed rest, analgesics and ROM exercises as tolerated.
rehab focuses on progressive mobility and
fractures of the proximal femur
classified as intra- or extra- capsular
intracapsular fractures have higher incidence of complications from disruption of circumflex femoral artery
- avascular necrosis
- delayed union
- non-union
intracapsular fractures
femoral head fx
subcapital fx
femoral neck fx
extracapsular fractures
intertrochanteric fx
subtrochanteric fx
shaft fx
hallmarks of DJD
- joint space narrowing
- sclerotic subchondral bone
- osteophyte formation
- cysts of pseudocysts in subcondral bone
- superior migration of the femoral head
difference b/w OA and RA
RA= entire joint space narrows. femoral head migrates into acetabulum
OA= WB surface loses cartilage space. femoral head moves superiorly
RA of the hip
- periarticular osteoporosis
- symmetric concentric joint space narrowing
- synovial cysts in periarticular bone
- axial migration of femoral head
- acetabular protrusion
avascular necrosis of the hip
- unilateral or bilateral
- crescent sign early
- disruption of blood supply near or within the proximal femur (trauma, infection, prolonged steroids)
thickening of the vessel wall
- radiation therapy
- lupus
- giant cell arthritis
thromboembolism
- alcoholism
- diabetes
- sickle cell disease
slipped capital femoral epiphysis (SCFE)
=post/med displacement of the proximal femoral epiphysis (head of femur slips off neck at the growth plate)
- most common disorder of the hip in adolescence
- onset often coincides with growth spurts
Developmental dysplasia of the hip (DDH)
=malformation of the hip joint found at birth or in young children learning to walk.
-because the head of the femur has not yet ossified, evaluation is often assessed by lines and angles between ossified structures
DDH line A
Hilgenreiner’s line
horizontal junctions of iliac, ischial and pubic bones at the center of the acetabulum
DDH line B
Perkin’s line
perpendicular line through outer edge of acetabulum
ossification of the femoral head, or the medial “beak” of the femoral metaphysis should be located in the lower, inner quadrant
DDH line C
acetabular depth assessed by the angle of a line drawn joining the inner and outer edges of the acetabulum
this angle should be <30 degrees
DDH line D
Shenton’s line
smooth continuous curve along the inferior border of the femoral neck connecting to the inferior border of the superior pubic ramus
unipolar hip hemiarthroplasty
older design
solid ball the size of the original femoral head
bipolar hip hemiarthroplasty
- developed to try and reduce the motion and articular cartilage wear in acetabulum
- despite lack of demonstrated benefit, bipolar prosthesis most commonly used today
