11/4 - Management of Knee OA Flashcards
what is the pathology of OA
erosion of articular cartilage
sclerosis of bone underneath cartilage
formation of osteophytes
why do you see osteophyte formation with OA
as get abnormal wear on bone, think Wolf’s law - bone grows when force is applied
- results in osteophyte formation
what s/sx can osteophyte formation cause
get osteophytes along margin of joint
- disrupts mobility
- lead to discomfort w movements into end range
how does OA typically present in the knee
usually in med compartment
- varus deformity
lat compartment (5-10%)
- valgus deformity
what dictates the presentation of OA w varus vs valgus deformity and why
get more load on different areas depending on if they have varus or valgus alignments
what are risk factors that inc risk of knee OA
- age
- joint injury, prev menisectomy, past surgery
- obesity
- occupational activity (ie heavy lifting, squatting, kneeling, stairs, cramped spaces)
why would a past surgery be a risk factor for knee OA
surgery changes original make up of joint
- disrupts biomechanics
- not sure why
relationship of physical activity/sports as a risk factor for OA?
inconclusive findings
- benefits of physical activity outweighs the load that could potentially cause OA
what is the general takeaway of the criteria for OA
all different
see pain/stiffness in morning that gets better w movement
- then worse again w more movement throughout the day
what does crepitus indicate
changes in articular cartilage
onset and course of OA
insidious
- progressively worsens
chronic presentation
- can have acute flare ups, but typically chronic
if there isn’t a clear mechanism of injury w anything, what is the first thing you want to do
clear lumbar spine
localized vs diffuse sx of OA
localized - varus/valgus alignment that loads specific compartment
diffuse - other involvment (ie meniscal)
why is swelling an important thing to manage asap
can inhibit ms and joint motion
WOMAC vs KOOS pt outcome measures
WOMAC - OA and TKA
- pain, function, stiffness
KOOS - OA, TKA, ACLR, meniscectomy, tibial osteotomy
- higher activity level pts
- pain, other sx, ADLs, QOL
what is the problem w patient reported outcome measures like the WOMAC and KOOS
people tired of filling out forms, but important thing to use in evaluation
classifications of OA
minimal = no radiological narrowing
mild = loss 1/3 joint space
mod = loss 2/3 joint space
severe = bone to bone contact
what does joint space between femur and tib indicate
amt of cartilage that is there
what is an important view of XR with OA
in WB-ing
- so you can appreciate joint space (how much cartilage is there)
how do you assess ROM in a PT exam and why
AROM -> PROM -> RROM
they are in control when you ask them to move
- if do PROM, they may be guarding
how should resistance be applied to assess strength in an exam
isometric resistance in resting position
why is erythema something to assess in a PT exam
palpable warmth
how active is inflammatory process
what is a consideration when assessing ROM
caution w overpressure
how can joint effusion present in OA (3)
intra-articular swelling
distended & thickened joint capsule
popliteal cyst
how can joint effusion limit knee flexion
only place for fluid to go in knee is post
- this can limit flex as bend knee, fluid disperses and pushes outward - only so much flex is possible
what relationship does joint effusion have to the quads and why is this important to consider
doesn’t take a lot of fluid to limit quads
- from mobility standpoint and ms ability to work stand point
no matter how much strengthening you do, if fluid is sitting there, gains are limited
what should be avoided when testing ms strength in OA
avoid resistance in full ext
- screw-home mechanism and closed pack position
test in mid range
what are 3 common impairments seen in OA
ROM
strength
balance
what relationship does meniscal path have to OA
meniscal path inc risk of early onset OA
what are 5 results from a deficient ACL d/t its neuromuscular characteristics
- dec capsular mechanoreceptors
- difficulty detecting joint motion/position
- dec proprioception
- dec neuromuscular control
- hamstring length changes
what does a brighter area on a radiograph tell you? what are the implications of this for OA?
more load or some inflammation/reaction there
less cartilage there
big component to creating sx
what can radiographic OA changes indicate
if changes present in TF and PF compartments, knee pain and function loss more likely
what are 5 characteristics of radiograph studies of OA
- dec radiographic joint space
- sclerosis of subchondral bone
- osteophyte formation @ joint margins
- subchondral cyst formation
- genu varus or valgus deformity
what are your basic principles of management of OA (8 - don’t overthink it)
- soft tissue healing
- control pain and swelling
- limit ms inhibition and atrophy
- early controlled ROM
- early initiation of ms activity and neuromuscular control
- proprioceptive training
- cardiovascular training
- sport-specific training
what are some interventions while managing swelling and pain
want to maximize mobility (both joint mobility and ms length)
- redistribute load
- get ms stronger and dec amt of load put on joint
why is it important to control inflammation acutely
- 1ml fluid associated w reflexive inhibition of quad
- 60% dec in knee ext strength d/t pain and fluid retention
what is the value of using NMES as an adjunct acutely
integrating estim w pts who are having difficulty w ms activation
- accelerate functional recovery
- prevent disuse atrophy
- reduce ROM deficits
- improve motor control
what is the value of using TENS in conjunction w exercise
benefit to this if pain is limiting factor
- dec pain
- inc quad activation and function
- dec knee stiffness
why is aerobic conditioning an intervention thrown in here w OA
superior to or equivalent to strengthening exercises
how would you prescribe aerobic conditioning for OA
endurance*
- UBE initially
- cycling - less impact than walking, but greater knee flex needed
- walking program
consider irritability when deciding walking or cycling
what are some ther-ex interventions (3)
proprioception
strengthening
- prox: hip ABD
CKC progression
- mod WB -> FWB -> r - WB
what are return to sport considerations when prescribing ther-ex
generate and dissipate forces
- eccentric ms actions
- sub max plyometrics (improve dynamic strength)
why do we want to work on eccentric ms actions in OA
shock attenuation impaired in individuals w joint dz
- we want to improve ability to generate and dissipate forces if return to sport
what is a consideration when prescribing sub max plyometrics in OA
rest interval should allow for full recovery
what should be considered about the plane of motion activities are in
in runners - frontal plane/lateral motions may be more difficult bc mostly doing sagittal movements
consider if sport is in one plane primarily and have motions be in other planes
why is manual therapy and joint mobs helpful in OA
mobilizations provide local and widespread hypoalgesic effects
- inc mobilit/ROM, distributing forces over larger area
what was the best use of manual therapy and exercise therapy as for freq in OA
manual therapy best in consecutive sessions (2x/wk)
exercise therapy best using booster sessions
- retest and progress exercise in booster sessiosn
what joint mobilizations are we going to do for knee OA and why
hip
- distraction: pain, all motions
- post glide: flex, IR
knee
- tibfem distraction
- ant tibfem: ext
- post tibfem: flex
- patellofem glides: sup/ext, inf/flex
what are the many number of reasons that ROM could be limited in knee (4)
swelling
quad weakness
ms length
limited ant glide of tib
what are 2 benefits of aquatic therapy over others
pain relief
reduced load on joint surfaces
what is the point of injections
neither are long-term solutions
think ab these things to inc tolerance to therapy to make meaningful change
when you use a cortisone injection and why
corticosteroid = anti-inflammatory
short term most effective to dec pain and swelling
- ex: walk daughter down aisle in 2wks
when would you use a hyaluronic acid (HA) injection and why
components of building blocks of articular cartilage
“lubricating joint” - helping w joint mobility
takes awhile for effectiveness to kick in - ramp up effect
- some people benefit and some don’t so insurance own’t cover
- ex: avoid surgery
what is a consideration of someone getting a cortisone injection in terms of surgery
most of the time surgeons will want pts to wait several months before TKA
- anti-inflammatory, disrupts healing
- don’t want to do something that requires robust healing response
what are 3 possible injections for OA
cortisone
HA
PRP
varus vs valgus loading on the bone
valgus inc load in lat compartment
varus inc load in med
getting more compressive load
when would you recommend an unloader brace for someone and why
if had varus/valgus alignment
if person had sx when active but fine walking around
- recommend unloader brace during those activities
brace only works when on
would be annoying to wear all the time for someone who has brace on all the time
what must be done before prescribing lateral shoe wedges
must assess mobility at subtalar joint
who is a lateral shoe wedge appropriate for and why does it work
if have varus alignment and good subtalar motion
creates eversion of calcaneus and more pronation at foot
- aka unload med compartment to change moment arm at knee
why wouldn’t a lateral shoe wedge work in some people
if don’t have subtalar joint motion, heel won’t move and this does nothing and could create problems elsewhere
what should you educate the patient on
no cure, only management
the benefits of the interventions you are giving
what is an OA arthroscopy/chondroplasty and when is this recommended
surgical debridement of arthritic areas
recommended for:
- meniscal tear or loose bodies
- pt c/o “catching/locking”
rarely done in isolation, see this when already having surgery on something else done and just “clean up”
rehab for a OA arthoscopy/chondorplasty
restore ROM
hip and quad strength
not waiting for anything to heal
who is an osteotomy indicated in
unicompartment OA
pts too young for TKA
bony malalignment contributing to valgus/varus force
what is an osteotomy
induced fx to remove/add wedge of bone to tibia or femur
- changes forces to preserve cartilage
rehab for osteotomy
healing time is similar to fx
- restricted WB for 4 wks
- no resistance distal to osteotomy to protect surgical site for ~4wks
CPM and early ROM
NMES for quads in full ext
what is removed and what is spared in a TKA
removed:
- distal fem to shape prosthetic
- prox tib
- menisci
- ACL
spared:
- PCL may be
patello femoral joint and TKA
TKA can be w or w/o patella resurfacing
cemented vs uncemented vs hybrid TKA
cemented
- most common
- most stable
uncemented
- higher failure rate
- younger pts
hybrid
- uncemented fem component
- cemented tib and pat components
cemented/uncemented TKA in outcomes and rehab
no difference in outcome
difference in what can do immediately post op
- cemented: load sooner
- uncemented: wait until bone heal around it
LOS after TKA
typically 0-3days in hospital
- dc home w services or rehab
WBing guidelines after TKA
cemented
- immediate WBAT
uncemented/hybrid
- TDWB or PWB up to 6wks
when do you dc knee immobilizer after TKA
usually until able to maintain TKE
TKA acute rehab interventions (3)
ROM
light strengthening
functional amb
6 outpatient rehab interventions after TKA
- progress ROM and strength
- scar mob when healed
- patella mob - all directions, prn
- normalize gait
- light aerobic exercise - bike, elliptical, walk
- sports - golf, low intensity
what joint mobs do you do after TKA
patellofemoral - ALWAYS and IMMEDIATELY
tibfem - NEED post op report
- if PCL sacrificing, will stress TKA mechanism
what are 6 complications of a TKR
- excessive blood loss
- DVT, PE
- infection - look at incision
- arthrofibrosis
- patella adhesions (mobs)
- failure
why can you see arthrofibrosis after a TKR and why should this be avoided
lot of scar tissue can form bc aggressive surgery w a lot of bleeding
once scar tissue forms, difficult to get rid of and mobilize
what are 6 causes of TKR failure
- loosening of components
- instability
- improper component placement
- infection
- osteolysis
- trauma
what is a partial knee replacement
unicondylar replacement
what are requirements for good candidates of partial knee replacements (5)
- OA limited to 1 compartment
- low impact sports/work activity
- minimal varus/valgus
- intact ACL
- BMI <32
what are the benefits to a partial knee replacement
immediate WB post-op
can be converted to TKA
spares a lot of ligamentous components bc not taking away lot of bone
