Hip Flashcards
Types of NOF #
intracapsular - subcapital, transcervical
extracapsular- basal
RF of fragility #
Non modifiable:
- old age
- female
- early menopause
- nulliparity
- family/ personal hx of #
Modifiable:
- increased risk of falls
- poor vision, vestibular dysfx
- LL weakness
- co-morbid (CCF, CVA)
- home hazards - reduction of bone strength
- osteoporosis
- steroids, alcohol, smoking
- immobility
- pathological bone conditions
- chronic liver/ renal failure
What is FRAX
WHO Fracture risk assessment tool: Gives 10-year probability of hip # and 10yr probability of a major osteoporotic #
Indications for THR
OA hips
pathological #
Acetabular involvement
revision of hip implant
Describe the garden classification
1 and 2 non displaced
1: incomplete #, incl valgus impacted #
2: complete
3 and 4 displaced and complete
3: incompletely displaced
4: completely displaced
Mgx of NOF#
children/ young
- undisplaced: hip spica
- displaced: preserve head! (60yo cut off)
> M&R
> secure int fixation: 3 cancellous screws/ dynamic compression screw
Old
- undisplaced:
65yo: cancellous screw
90yo: hemiarthroplasty (uni/bipolar) - displaced: no need preserve head
- hemiarthroplasty
- THR (for active adults)
Cx of NOF #
- Bedbound cx: thromboembolism, pneumonia, sores, UTI
- AVN femoral head
- non union (cause: poor blood supply, imperfect reduction, poor fixation, poor healing)
- secondary OA
Mgx of non union
<50yo: bone graft across # + reinsert fixation device
>50yo: hemiarthroplasty/ THR
Blood supply of femoral neck
a) Nutrient artery of femur (from profunda femoris)
b) Retinacular arteries in capsule (from medial and lateral circumflex arteries from profunda femoris)
c) 10% by ligamentum teres vessels (from obturator)
Classification of intertrochanteric #
Evans-jensen classification
Mgx of
- intertrochanteric #
- subtrochanteric #
similar
M&R under x ray
internal fixation with DHS (for IT#), or cephalomedullary nail (PFNA) for IT and subT#
post op weight bearing with crutches
Types of hemiarthroplasty
Unipolar
- Thompson: no holes, need cement. Has neck
- Moore: has 2 holes, no need cement. No neck.
Bipolar
- more sizes than unipolar
- less friction
Trendelenburg test
- when is it positive
- causes of positive test
- SSS: Sound side sags Etiology abductor weakness - fulcrum problems: hip OA, AVN - lever arm problems: NOF #, coxa vara - effort: weak abductors - nerve problems: superior gluteal n or L5 - myositis, poliomyelitis - others: perthes disease, DDH, SCFE
what is the landmark of the hip joint
2cm below and lateral to midpoint of inguinal ligament
Measuring
- relative limb length
- true length
most comfortable positive with legs parallel. from xiphisternum to medial malleolus on each side
Square the pelvis (both LL are right angles to line joining 2 ASIS)
- ASIS to medial malleolus
Explain the galeazzi test
done when there is a true length discrepancy
(ensure both malleoli touching)
when knee of affected limb is proximal = femoral shortening
knee is distal = tibial shortening
6 lines to look for in pelvic x ray looking for acetabular #
- iliopectineal line
- ilioischial line
- acetabular tear drop
- dome
- anterior wall of acetabulum
- posterior wall of acetabulum
causes of positive galleazi test
previous femur #
AVN head of femur
perches, DDH, SCFE
previous polio
What is the mgx of perthes
Abduction splint,
Realignment osteotomy
What is the mgx of SCFE
surgical fixation
Approach to hip pain
Referred pain: disc dz, hip pain to knee
Joint: infection, OA, RA, perthes, SCFE, AVN
Periarticular: Hernia, tendinitis, bursitis, synovitis
mimics: SI pathology, spine, gluteal muscle, iliotibial pathology, non ortho (hernia, LN, PID)
Most sensitive hip test for quick screening
Internal rotation
What is Bryant’s triangle
when pt is supine
- detect disturbance of normal anatomy of the femoral head and neck
- right angled triangle with lines between asis and greater trochanter
- to determine if shortening if above or below the greater trochanter
what is the normal neck/shaft angle of the hip
- coxa varus
- coxa valgum
normal: 120-135deg
<120 coxa varus
>135 coxa valgum
causes of foot drop
- bilateral causes
- cortical foot drop: stroke, SOL
- L5: PID, lumbar spondylosis
- sciatic nerve: pelvic/hip#, hip posterior dislocation
- common perineal nerve
- ext pressure (casts)
- trauma (tibia/fibular #)
- masses (ganglion, popliteal cysts, tumor
- DM, leprosy
bilateral:
- peripheral neuropathy
- b/l L5
- cauda equina syndrome
- spastic paraplegia
Causes of hip pain
Vascular: perthes, AVN Infection: OM, septic arthritis, TB, transient synovitis Trauma: OA, dislocation, fracture Autoimmune: RA Congenital: SCFE, DDH
RF for AVN
Vascular: hemoglobinopathies (sickle cell anemia)
Infective: septic arthritis
Trauma: post fracture, dislocation (e.g. NOF#)
Autoimmune: RA, SLE
Metabolic: alcohol intake, obesity, smoking, caisson (deep sea diving), gaucher (AR dz of glucocerebroside metabolism), cushing, anti phospholipid syndrome)
Iatrogenic: steroid
Neoplastic infiltration
Congenital: Perthes, SCFE, clotting disorder
Idiopathic
Others: acetabular dysplasia, pagets, coxa vera
What are the stages of AVN
Ficat Arlet Staging
0: preclinical: no signs no pain, hip at risk
1: pre-radiographic: bone death with no structural change (pain)
2: pre-collapse: repair and early structural failure (pain + stiffness)
3: collapse: femoral head distorted (pain + stiff + limping)
4: osteoarthritis (v pain + stiff + limp)
What is the management of AVN by stage
1-2: Conservative vs surgical
- conservative (for early or surgically unfit): bed rest, weight relief (crutches), splintage, NSAIDs analgesia, bisphosphonates to slow resorption, physio, control RF
- sx: core decompression KIV bone grafting (from fibular)
3: Surgery
- femoral head resurfacing
- hemiarthroplasty
- sugioka transtrochanteric rotational osteotomy
- realignment osteotomy (redistribution of weight bearing)
- Tx as per OA
- resurfacing arthroplasty
- THR (relieves pain due to removal of capsule fibrosis)
Imaging Expected for AVN by Stage
Stage 1: preradiographic
- X ray: normal
- MRI: T1 shows decreased signal within femoral head (edema) - single low density line
- bone scan: increased uptake
Stage 2: pre-collapse
- X ray: subarticular segment increased bone density due to increased sclerosis/ cyst formation. normal contour, some ostoepaenia
- MRI: T2 shows double rim sign (hypointense line - granulation, hyperintense line - sclerosis)
- bone scan: increased uptake
Stage 3: collapse
- X ray: contour step off, crescent sign (subchondral lucency - collapse), acetabulum intact
- MRI: cescent sign, cortical collapse
Stage 4: OA
- X ray: LOSS, shortening of limb, collapse and flattening of head, loss of sphericity, superior subluxation of femoral head
- MRI: degen changes
