Knee 2 (test 3) Flashcards
attachments/path of the ACL
attaches centrally and anteriorly on tibial plateau
runs posteriorly, superior, and lateral
attaches at lateral aspect of intercondylar fossa
ACL restrains what
excessive anterior tibial glide
secondary restraint to tibial IR
prevalence of ACL injury
20% all knee injury
younger females
non modifiable risk factors for ACL injury
female > males
2 weeks following start of period = ligament laxity
bony morphology:
-narrow intercondylar femoral notch
-post tibial slope and hyperextension both correlated with non contact ACL
congenital hypermobility
modifiable risk factors for ACL injury
high shoe-surface interaction/friction
high BMI
possible risk factors we can change for ACL injury
bracing = inconsistent benefit
muscle strength
-lower overall with ACL tears
-ham/quad ratio strength
loading pattern
why would hamstring quad ratio affect ACL injury
predicts LE control
hamstrings prevent anterior translation
lower ratio present in females vs males
what altered loading patterns affect the ACL
impaired LE control
loading patterns happen earlier and nearly 2x faster with impaired control
thus this causes decreased knee flexion with larger ground reaction forces/harder landing (land with stiff knee to offset possible knee valgus that would occur otherwise)
what can you see with impaired LE control
increased dynamic knee valgus and hip add
very easy to see with vertical drop test
poor control is defined by
significant valgus movement
knee is medial to foot
reduced control is defined by
some valgus movement
knee not entirely medial to foot
good control is defined by
no valgus
knee vertical to toes
what might you see with the trunk with ACL injury/modifiable risk factor
greater trunk lean toward support limb
greater trunk RT toward support limb
what does it mean that those at higher risk for ACL injury have greater activation of visual motor strategy vs sensory motor strategy
relying heavily on their eyes for focus
have them close their eyes and movement is poorer/less stable
risk factors for secondary ACL injury
same as primary ACL plus excessive femoral IR moment
% of ACL injuries that are contact vs non contact
non contact = 50-70%
contact = 30%
functional questionaires for ACL
international knee documentation committee (IKDC)
Knee Outcome Survey (KOS)
typical sprain S&S
empty painful endfeels (acute)
limited motion if acute, excess if not
popping
pain with distraction
joint laxity
+ special tests for ligament
symptoms of ACL injury
consistent with any ligament injury
effusion, popping, AND giving away following trauma
WBing activities with likely giving away
signs of ACL injury
consistent for ligament sprain plus
ROM is limited paingul particularly with hyper ext and IR
special tests for ACL
anterior drawer + (possible - if HS tight)
lachmans (possible false neg due to blocked anterior glide via severe swelling that tightens capsule, HS guarding, or meniscal tear)
+ pivot shift
other possibly + for additional tissue damage (i.e. meniscus, MCL, etc)
ACL injuries are often accompanied by arthrogenic muscle inhibition of quads due to what factors
pain
effusion (joint swelling)
-involved knee inhibition
-uninvolved knee inhibition
-amount of swelling not always correlated to amount of inhibition
joint laxity/giving away
muscle weakness/correlation
NOT due to denervation
ACL injuries are often accompanied by arthrogenic muscle inhibition of quads due to what factors
pain
effusion (joint swelling)
-involved knee inhibition
-uninvolved knee inhibition
-amount of swelling not always correlated to amount of inhibition
joint laxity/giving away
muscle weakness/correlation
NOT due to denervation
what does arthrogenic muscle inhibition mean
it starts at the joint/because of a joint issue
muscle inhibition of quads with ACL injury leads to
atrophy/more inhibition/weakness; deficits common 2-4 years after injury
determined by observation, palpation, and muscle testing
need to take seriously and communicate importance of staying on top of exercises to pt
can also affect other side/knee as well
PT Rx/prognosis for ACL injury if they are not returning to high risk activities
most can return to low risk activity without sx with good outcomes
3 primary/early goals for ACL injury
full/near full ROM (especially ext)
minimal to no swelling
quad activation/endurance/coordination
how to ensure ACL pts obtain full ROM
immediate mobilization in PT for ROM, pain, and minimizing immobilization effects
full ext should be obtained no later than 4 weeks (wont happen with everyone, especially if other structures like meniscus are involved)
-predicts ext at 12 weeks and lower risk of OA
what may indicate quad activation/endurance with ACL injury
SLR without extension lag (bend in leg)
quad set > 90% of uninvolved side (could be misleading if uninvolved side is also experiencing inhibition)
PT Rx for ACL strain
early WBing as symmetrical as possible w/o detrimental effects
POLICED
functional bracing (comes later); more beneficial with ACL deficiency, conflicting support with ACL reconstruction
weak support for continuous passive motion devices
why is bracing inconsistently supported for injury
little accessory movements/translations can still occur within brace
for ACL, outside of hyperext, brace wont prevent any other motions that could also cause pain
MT for ACL
initiate post op
describe purpose of neuromuscular electrical stimulaiton for MET for ACL
neuromusclular electrical stimulation (NMES) for activation/coordination/strength:
significant increase in quad strength ‘no significant
changes with function
isometrics at varying angles based upon symptoms
discontinue once quad index > 80% uninvolved side
general MET parameters for ACL
assumptions must be made about arthrogenic muscle inhibition
intense resistive training without inducing pain must be performed eventually
emphasize both concentric and eccentric training
non WBing vs WBing activities guidelines for ACL
load is generally greater with non WBing activities than WBing because open chain/non WBIng only activates quads but WBing will generally activate HS and other muscle groups as well to counteract the force of the quads and provide more symmetrical muscle activation across the joint
non WBing or OKC activities are less of a concern than in the past
greatest loads are found within 50 degrees of full ext with both WBing and non WBing (so i.e. you can do a knee ext from 90 to 45 only or with closed chain you dont want the pt to squat with knees over toes)
how does the stress on the ACL change with squatting, lunging, and leg press
increases with knees beyond toes
decreased with fwd trunk lean
walking guidelines/general exercise guidelines with ACL injury
with walking there is as much load as non WBing knee ext due to repetitive terminal knee ext
this is several times greater than other WBing activities
this means that both OC and CC knee activities early and often is OKAY…especially if they are walking and using correct trunk and LE control
goals for hamstring strength and coordination emphasis of ACL Rx
males: hams > 66% of quad activity
females: jams > 75% of quad activity in females
this value could be skewed if there is quad inhibition present
neuromusclular training that should be present in an ACL Rx
normal strength does not equal proper neuromusclular or LE control
trunk proprioception and kinesthesia to minimize lean and twist
components of LE proprioception and kinesthesia that should be incoorporated with neuromuscular training for ACL Rx
minimize frontal and transverse plane motion
promote sagittal plane knee and trunk flexion
decrease GRF with softer landing
progressive speed and difficulty
emphasis on jump landing and balance
timing for MET Rx for ACL
needs to be at least 2-3x/week for 6-10 months
bilateral, for cross edu = less deficit compared to only exercising involved knee
effectiveness of blood flow restriction
no better than intensive exercise
can increase growth hormone but can also decrease myostatin which would limit cell growth (cancels out)
importance of motor learning for ACL MET
important to improve movement patterns
use language they can understand and help cue proper movement
examples of motor learning with a external focus
improved balance/coordination
higher vertical jump
more force production
greater knee flexion
softer landing
how could you improve motor learning by adding observation to practice
competition with others (motivation/responsibility)
real time feedback/post exercise feedback
plyometrics for ACL
increased loading with rate of deceleration (need to control descent with good movement patterns)
vertical jump similar loading to NWB ext on ACL (with proper movement patterns)
what % of ACL tears include meniscal tears
22-86%
how can meniscal involvement with ACL tear affect recovery
if a partial meniscectomy there is no change
if there is a meniscal repair performed = slower progressions due to greater protection required for meniscus healing
may slow achievement of full ROM due to decreased WBing required for said protection
how many ACL injuries have bone bruises involved
80% have bone bruise
what is the general timeline for recovery with ACL tears involving a bone bruise
if skeletally immature (young) healing = 2 weeks to 3 months
skeletally mature healing = 1 month to 1 year
average is 3.2 months
overall bone bruise is a delaying factor that leads to more difficulty reaching full ext and proper quad function (inhibition)
what happens if there is a MCL tear with ACL
MCL tears generally are not surgically repaired
if ACL is torn then often surgeons will wait 10 weeks for MCL to heal before repairing ACL (better outcomes vs earlier sx)
precuations if there is MCL injury/involvement
only sagittal plane activity for 4-6 weeks
limit tibial ER and valgus stresses
what % of ACL injuries involve articular cartilage defect
36%
what are the treatment options if there is articular cartilage involvemetn
debridement (abrasion) = WBAT for 3-5 days and no delays to ACL rehab
osteoarticular transport system (OATS) and autologous chondrocyte implantation (ACI) (cultured) = most conservative guidelines and greatest delays
microfx of bone underneath to stimulate bleeding = NWB for 2-8 weeks; delay to ACL rehab
** dont need to know specifics; just know if articular cartilage is repaired then it will delay ACL timeline
order of effectiveness of 3 articular cartilage repair options
OATS > ACI > Microfx
why is ACL hard to heal/often surgically fixed
clotting repair is inhibited by synovial fluid
few return to high risk activity without sx due to continual instability
what % ACLs are surgically repaired
65%
what are the 3 arthroscopic techniques for ACL reconstruction
bone patellar tendon bone (BPTB) grafts- have both autograft and allogract
semitendinosus/gracilis (SGT) graft
what is allograft vs autograft
allograft = cadaver
autograft = from pt
how does pre op weakness affect outcomes of ACL sx
the stronger you start the better you are likely to come out
describe a BPTB autograft
incision over opposite patellar tendon
remove middle 1/3 of: bone of patella, patellar tendon, and bone of tibial tuberosity
what is a complication that may occur with BPTB autograft
up to 1/3 develop anterior knee pain
graft strength timeline
initial weakining within 1st 4 weeks
incorporation of graft into bone at 6-8 weeks
dense fibrous tissue at 8-12 weeks
symptom difference with BPTB allograft
symptoms improve faster than the graft incoorporates into the body
pt may feel like they can due more since they didn’t have the extra trauma of an autograft but it actually takes longer for the donor graft to incorporate into the body than if it was their own tissue
graft strength for allograft
incorporation if graft into bone at 8-12 weeks
dense fibrous tissue at 8-12 weeks
delayed timeline and longer rehab
why might one choose an allograft vs auto
if pediatric pt = dont want to interrupt growth plate
if pt has already had multiple ACL repairs and no longer has viable tissue to donate
can avoid anterior knee pain from graft being taken
advantages of STG graft
prepubescent youth to avoid growth plate complications
avoids anterior knee pain
Rx if STG graft is performed
may start pure strengthening of hamstrings at 6-8 weeks
delay heavy strengthening with hams for 12 weeks
prognosis for ACL recovery
18-24 months post op
muscle weakness and impaired neuromuscular control remain
all grafts and bone show continued healing on imaging
inhibition, atrophy, and weakness are common out to 2 years and 4 years post op (even in both LEs)
prognosis for BPTB grafts at 40 months
45% resumed pre injury level
29% returned to competitive sport
failure rate for ACL
up to 30%
75% of 2nd tears occur between 18 and 24 months
reduced injury rate by waiting at least 9 months to return to play
*worse if meniscal or articular cartilage involvement or ext lag
describe PCL
thicker/stronger
attaches central/posterior on tibial plateau
runs superior/anterior
attaches anteriorly on medial aspect of intercondylar fossa
PCL primarily restrains what
excessive posterior tibial glide and IR
least injured knee ligament
PCL
etiology of PCL sprain
hyperflexion primarily but also some with hyperext
S&S of PCL injury
consistent with any ligament injury
limited and painful ROM (least pain in ER)
+ PCL special tests
special tests for PCL
quads active
post drawer
post sag
reverse pivot shift
PT RX for PCL
ligament Rx plus emphasis on limiting posterior tibial gliding
describe MCL
flat broad ligament with 2 bands
runs from medial condyles of femur and tibial
restraint of MCL
anterior band = limits flexion
posterior band = limits hyperext
MCL attaches to
medial meniscus
posterior capsule
adj muscle and tendon units
SO if you have a pt with MCL sprain you need to check other surrounding structures
most injured knee lig
MCL
etiology of MCL sprain
excessive valgus and or ER stress and or hyper ext
S&S of MCL sprain
general ligament S&S plus
impaired ROM least limits with IR
+ MCL special tests adn possibly medial meniscus special tests
TTP
special tests for MCL
valgus stress at 0 and 30 degrees
more extended position tests other structures like cruciates and capsules
Rx for MCL
ligament RX plus
early protection with valgus and ER stress and end ranges of flx/ext
most wont need sx bc ligament is extraacrticualr and can scar/heal on blended capsule
describe the LCL
round cordlike ligemetn
attaches to lateral condyle of femur and fibular head
no attachment to menisci
primary restraint to excessive varus and ER stresses
prevalence of LCL injury
string ligament so rarely injured
etiology of LCL injury
excessive varus and or ER stress and hyperext
S&S of LCL injury
consistent woth ligament injury plus
ROM limited and painful especially in ext and ER
+ LCL special tests
TTP
special tests for LCL
varus in 0 and 30
PT Rx for LCL injury
like ligament Rx plus
early protection with varus and ER stress
may need sx because ligament remains from the capsule even though its extraarticular
MET for all sprains
combo of supervised and HEP better than either alone
combo of open and closed chain exercises
coordination training
