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