Pelvis & Hip Flashcards
S3Q1
PELVIS: Anatomy - Pelvis
what, 2 forces, 3 innnominate (3) + acetabulum percentage
birth - what, visible (4), cartilage ages (2), M vs. F (1.2)
PELVIS
- keystone
- WB of UE x GRF of LE
- ilium (sup 2/5), ischium (pos 2/5), pubis (ant 1/5)
- acetabulum (50% of head)
- cartilaginous at birth; ossify = skeletal maturity
- birth: upper ilium, lower ischium, medial pubis, majority of acetabulum (cartilage)
- tri-radiate cartilage: fuse by 17y, full by 20y
- M&F puberty: M = wider AP, F = wider brim & transverse diameter
PELVIS: Anatomy - Ligaments
iliofemoral, pubofemoral, ischiofemoral - from to, purpose=purpose
extra (2)
- transverse acetabular
- ligamentum teres
- iliofemoral: AIIS to intertrochanteric line
- pubofemoral: inf acetabular rim to inf femoral neck
- ischiofemoral: ischial portion of acetabulum to sup femorla neck
- limit hip EXT = stabilize pelvis on femur when standing
PELVIS: Radio
ideal views (1.2)
CT scan - protocol, CTa see (2) + contrast where & color
MRI - protocol (2), for (2), MRa for (2)
- ideal: AP pelvis, AP & frog leg for femur
CT scan
- protocol: most sup ilium to most inf ischium
CTa
- see: labrum, joint cartilage
- contrast to folds of joint = black in fluoroscopy white in CT
MRI
- protocol: hip & pelvis simultaneous
- iliac crest to LT
- for: clarify end-stage condition, post-op
- MRa: labral tear, femoroacetabular impingement
PELVIS: Radio
AP pelvis - see (5), lines (2), ray (2), how (1=1)
AP hip femur - see (6), ray, how (1=1)
lateral frog - see (4), ray, how (2), not for (2) + use what
AP PELVIS
- see: pelvis, sacrum, coccyx, lumbosacral, prox femur, all joints
- ilioischial line: pos colum of acetabulum
- iliopectineal line: ant
- ray: midline of pt, perpendicular to receptor
- how: IR = see femoral neck instead of shortened
AP HIP & PROXIMAL FEMUR
- see: acetabulum, femoral head & neck, prox 3rd of shaft, GT, partly LT, angle of inclination
- ray: femoral neck
- how: IR 15 = only partly LT
LATERAL FROG LEG
- see: femoral head & neck, prox 3rd of shaft, GT, LT
- ray: femoral neck
- how: FABER, can be (B)
- not for: post-op, nondisplaced femoral neck fx (= axiolateral infsup groin lateral projection)
PELVIS: CT Scan
bone density - check (1=3) + specific of 3rd (2)
cartilage/joint - check (1) where, smooth chondral structures (2), acetabulu, shape & cartilage
soft tissue - check (2G)
bone density
- erosion = disease, infection, irregularities of acetabulum (OA, tumor)
cartilage/joint space
- check: loose bodies in joint cavity
- smooth chondral surface: femoral head, chondral surface of acetabulum
- acetabulum: horseshoe-shaped, central & inf have no cartilage
soft tissue
- check: capsule (not visible unless effusion), bursa (iliopsoas>trochanteric)
PELVIS: CT Scan
axial - see (7)
sagittal - see (5)
coronal - see (8)
axial plane
- see: femoral head in acetabular fossa, medial wall of acetabulum, ant & pos rim of acetabulum, GT, LT, sacrum, pubic rami
sagittal wall
- see: angle of acetabular cup, acetabular roof, pubic symphysis, SIJ, iliopsoas (ant to hip)
coronal plane
- see: (B) hip joint, acetabulum, femoral head neck shaft (+ angles), GT, LT, sacrum, ilium, SIJ
PELVIS: MRI
alignment - what angle + where (2) + normal value & indications (1=2)
bone signal - check (3), AVN signal, fx signal
cartilage - check (2), labrum shape + attachment + signal
soft tissue - check (4), pulvinar what, strain signal
alignment & anatomy
- alpha angle: femoral head & neck, where sphericity ends; > 55 = CAM lesion (acetabular impingement & OA)
bone signal
- check: osteochondral, tumor, cyst
- AVN: serpentine low signal
- fx: low signal
cartilage
- check: osteochondral, labrum
- labrum: triangular, attached to rim, dark in all
soft tissue
- check: synovium, bursa, fat pad, muscle
- pulvinar: fibrofatty tissue pad filling up acetabulum of kids
- muscle strain: high signal on T2
PELVIS: MRI
axial - see (4.6)
sagittal - see (2.4.2)
coronal - see (4.3)
axial plane
- acetabulum, pulvinar, alpha angle, labrum
- sacrum, pubic symphysis, ilium, SIJ, GT, LT
sagittal plane
- sphericity, superior cartilage of acetabulum
- ant muscles: iliopsoas, RF, sartorius, VM
- pos muscles: hamstring, quads
coronal plane
- (B) hip joint, prox femur, ilium, SIJ
- glutmax, ADD, ABD
PELVIS: Conditions - Trauma
low energy - example (2), what view + see what, optional views (2), CT scan for
high energy - structure, pelvic fx usually has what so use what projection
low energy
- avulsion or indiv bone fx
- pelvic oblique/judet view: columns of acetabulum
- optional: pelvic inlet (central ray at 40 caudad), pelvic outlet (30 cephalad)
- CT scan = fx in complex areas
high energy
- pelvic ring disruption
- pelvic fx usually has visceral injury = CT scan of thorax abdomen pelvis (TAP)
PELVIS: Conditions - Fx of Pelvis
MOI (3), pelvic ring what, main determine, view (3)
complications (4)
tx - stable + when full function, unstable (4)
- MOI: MVA > falls, pedestrian motorcycle
- pelvic ring: osseous cage formed by coxal bones & sacrum
- stability = determines prog, tx, rehab
- view: AP pelvis, pelvic inlet, pelvic outlet
- complications: infection, thromboembolism, malunion, post-traumatic arthritis
tx
- stable fx (full function by 6-12w): ROME, rest, analgesic
- unstable fx: internal fixation, external fixation, skeletal traction, combination
PELVIS: Conditions - Fx of Pelvis
stable fx - what, 4 types + 2nd is common in who & d/t (3)
unstable fx - what, associated (1), 3 types + structures affected
STABLE FX
- no disruption of articulations
- ischiopubic ramus fx: almost half of pelvic fx
- avulsion of ASIS AIIS ischial tuberosity: in athletes d/t contraction of sartorius, hamstring, RF
- iliac wing fx, sacral fx
UNSTABLE FX
- disruption of 2+ sites
- associated: internal hemorrhage
- vertical shear/malgaigne fx: unilateral sup & inf pubic rami, ipsilateral SIJ
- straddle fx: all 4 ischiopubic rami
- bucket handle fx: 1 ishchial ramus, pubic ramus, contralateral SIJ
PELVIS: Conditions - Fx of Acetabulum
MOI (1), view what so use what
complications (5.3)
configuration - by hip position + lead to (1.2.2), by anatomy + what area/appearance (1.1.2)
tx - displaced (1), non-displaced (1)
- MOI: impact of head into acetabulum
- view: difficult in AP so get judet
- complications: infection, AVN, HO, malunion, post-trauamatic arthritis, nerve (sciatic femoral sup gluteal)
configuration by hip position
- neutral impact on GT = transverse fx
- FLEX ABD = pos acetabular fx, pos dislocation
- FLEX ADD = less pos acetabular fx
configuration by anatomy
- ant column fx: iliopubic area
- pos column fx: ilioischial area
- both: transverse fx, t-shaped configuratiom
tx
- displaced: surgical
- non-displaced: skeletal traction
PELVIS: Anatomy - Femur
what, ossification ages (4+1)
angles (2) + where
FEMUR
- largest bone
- ossify: shaft (birth), head (3-6m), GT (4-5y), LT (9-11y), all by late teens
- angle of inclination (neck): 175 –> 125-135
- anteversion (center of head & neck to center of condyles): 40 –> 15
PELVIS: Conditions - Fx of Prox Femur
epidemiology - sex, condition
MOI - 1st, 2nd who (2), 3rd who + d/t (4)
views (3)
advanced - what (3.1) for (3.1)
- epi: F osteoporotic
- MOI: falls > MVA (children & young adult) > stress fx (young adult d/t cyclic, ballet, military, distance running)
- views: AP, mediolat frog leg, axiolateral groin
- CT, MRI, radionuclide bone scan: impacted, subtle fx, negative radio
- MRI: stress fx
intracapsular
PELVIS: Conditions - Fx of Prox Femur
intracapsular - types (3) + specific (2), complications (2) + d/t, tx per age (1.1)
extracapsular - radio finding + d/t, types (2) + where, tx (2)
INTRACAPSULAR
- types: femoral head, subcapital, femoral neck (transcervical & basicervical)
- complications: AVN & union d/t circumflex artery
tx:
- young: 3 cancellous screws
- elder: partia/total prosthesis
EXTRACAPSULAR
- more ER d/t muscles mostly in extracapsular
- intertrochanteric: between GT & LT, 50%
- subtrochanteric: LT to 5cm below
- tx: ORIF, prosthesis
