conditions for awareness Flashcards
what is avascular necrosis (AVN)?
death of bone tissue due to lack of blood supply
tiny breaks in bone can cause bone collapse
What are possible causes of avascular necrosis?
Joint or bone trauma:
- Fracture e.g. femoral head
- Cancer treatments involving radiation
- Injury such as dislocated joint
Non-traumatic:
heavy drinking
steroid abuse
- can both cause hyperlipidemia
Glucocorticoid intake
cigarette smoking
Obesity
medical conditions e.g. sickle cell anaemia or systemic lupus
What are symptoms of avascular necrosis
pain
decreased ROM
where is AVN often seen
most common hip
also:
humerus
knee
talus
wrist e.g. lunate or scaphoid
how may AVN be diagnosed
through x-ray
what are the stages of AVN
Stage 1: radiographic changes absent. MRI is required for identification, asymptomatic
Stage 2: 1st stage radiographic changes. stage characterised by sclerosis of superior central portion of joint head +/or osteopenia +/or subchondryal cysts
Stage 3: articular surface is depressed so that round contour is compromised without being significantly deformed. creates joint space narrowing
stage 4: stage characterised by a wide collapse of subchondral bone and destruction of underlying trabecular pattern. can lead to secondary arthritis
stage 5: articular surfaces are affected = joint dysfunction
How is AVN diagnosed
Thorough check of patient history e.g. steroid use and alcohol abuse, age (younger than those with OA)
Physical examination
Early MRI screening
Radiographs at more advanced stage
What outcome measures may be used for AVN
Dependent on joint affected:
Harris hip score
4-item pain intensity measure
NRS
VAS
Hip disability and OA outcome score (HOOS)
What is the Harris Hip Scale
Evaluates various hip disabilities and was developed for after hip surgery
10 items covering pain, function, absence of deformity and ROM
Pain: severity, effects on activity and pain meds need
Function: ADLs and gait
Deformity: hip flex, add, IR, extremity length discrepancy
Hip ROM
Higher score= better outcome
<70 = poor, 70-80 = fair, 80-90 = good, 90-100 = excellent
What are +ve and -ve of the Harris Hip Scale
Has excellent test-retest reliability
Inter-rater reliability reported by Kirmit et al as good-excellent
No major diffs to WOMAC or short form 36
Has been found to have unacceptable ceiling effects in 31 of 59 studies
FOund by Shi et al that HHS was responsive to pain and function 6 months post op but weak 2 year FU
what is the HOOS
questionnaire intended to understand pts opinion’s about their hip and associated problems and to evaluate their symptoms
How is AVN managed medically
Pharmacologically
- anticoagulants
- statins
- vasodilators
can delay progress of joint degeneration at early stages
Surgery
- core decompression for stages 1+2 helps increase blood flow allowing the promotion of neo-vascularisation that may stimulate new bone growth
- bone grafts may also be carried out
- osteotomy may be carried out which changes alignments or shortens or lengthens bone to decrease load form necrotic bone but can only be performed in younger patients
- THR (arthroplasty) may have to be done if stages 3 or 4
How is AVN managed in terms of physiotherapy
gait aids may be used
exercise to maintain mobility and strengthen surrounding muscles
also essential post surgery
What are the goals of AVN physiotherapy
relieve symptoms
prevention of disease progression
improvement of functionality
