Ligamentous Injuries of Knee Flashcards
What is the primary role of the ACL?
primary restraint to anterior tibial translation, greatest stress at 20-30 degrees flexion
secondary restraint to tibial ER
What is primary MOI for ACL?
fixation, rotation and valgus force and also deceleration and hyperextension
What percentage of ACL injuries also damage meniscus?
70%- usually with valgus stress
What is PP of ACL?
hearing or feeling a pop, acute onset of pain, sensation of giving way, delayed onset of swelling
What is the gold standard for ACL testing?
Lachman’s
When is a primary repair indicated?
true avulsion- teens, ligaments stronger than bones
What are two types of grafts for an ACL reconstruction?
allo- cadaver, possible longer healing time
auto- creates another morbidity in knee
How long does it take a patellar graft to be vascularized and innervated?
8 weeks- blood
innervation - 6 months
What is an important thing to remember about a patella tendon autograft?
donor site may need 6-8 weeks healing prior to tolerating quad load greater than 60 degrees
Which type of graft will have the strongest holding strength?
semitendinosous graft
What are advantages of a PT graft?
excellent strength, excellent long term results, allows for aggressive rehab (biological tissue healing as its bone to bone healing)
What are disadvantages of PT graft?
possible extensor weakness, may lead to patella fracture, tendon rupture, tendinitis, excessive scar tissue
Why is their a potential for excessive scar tissue for PT graft?
because they are doing two procedures there is going to be a lot of bleeding which leads to scar tisseu
What can be done to help prevent scar tissue?
soft tissue work and patella mobs
What are advantages of a HS graft?
much stronger than patella, extensor mechanism intact
What are disadvantages of a HS graft?
limited long term F/U studies, rehab is slower as its only soft tissue healing
What is rationale behind doing a double bundle ACL reconstruction?
single does not adequate restore mobility and may lead to OA sooner, double replicates natural ACL which has 2 bundles
What does the term ligamentization refer to?
graft is strongest on day its implanted but will decrease in strength and will be lowest at 3 months post op
Which kind of graft has a slower recovery time?
HS slower than patella but won’t affect outcome measures
What are the major success criteria for ACL rehab from a PT prospective?
restore LE strength and full ROM, normal gait, pain free activity, return to pre injury function
When is the ACL under most amount of strain?
stressed throughout all ROM but most when quad activity is between 40-0 degrees
What are major treatment principles for ACL?
increase weight bearing, knee complex strength, edema control, proprioceptive training, endurance training, agility activities
What are precautions for post op if pt also has a meniscal injury?
may not be WBAT, no deep squats, no isolated HS for 8 weeks
What should goals for pre-op rehab be before ACL reconstruction?
- ROM should be equal to contralateral knee
- volitional quad activation, no lag with SLR
- minimal to absent joint swelling
What are goals for first week after surgery?
passive knee extension to 0 degrees
flexion to 90 degrees- patella mobs, bike with no resistence
What are goals for week 2 of rehab?
full knee extension, SLR without lag, flexion greater then 110 for knee(unless meniscus involved), walking without crutches, reciprocal stair climbing
What are sample interventions during week 2?
Patella mobs, prone hangs, wall squats, hip/calf strengthening, balance
What are goals for weeks 3-5 post op ACL?
improve quad strength to 60% of uninvolved, flexion ROM within 10 degrees of opposite side, enhanced proprioception, improve endurance
What are interventions weeks 3-5 post op ACL?
bike over 10 minutes, balance- perturbation, single leg work
What are goals for weeks 6-8 post op ACL?
normal gait, symmetrical ROM, quad strength 80% of uninvolved
When can a running program potentially begin?
for patella graft around 8-12 weeks must have little to no swelling, adequate strength, and must not have pain or swelling after run
What are goals and interventions for weeks 9-12 post op ACL?
quad strength 80% opposite leg, hop tests 85 % (12 weeks)
sports specific and agility work
When can return to activity work resume post op ACL?
16 weeks potentially need to have no swelling full ROM, completion of running program, 90% quad and hop test
What are two areas for female athletes can PT control most in ACL prevention?
neuromuscular strength and coordination
What are intrinsic risk factors for ACL injury in females?
age, strength, flexibility, joint geometry, joint laxity, anatomical alignment, hormones
What are 4 major risk factor categories for ACL in females?
- environment
- anatomical
- hormonal
- neuromuscular
What anatomical features in females lead to more ACL injuries?
larger Q angle, APT, wider pelvis, hip ante version , increased genu valgum, increased laxity and flexibility, less developed thigh muscles
What is the main difference in femoral notch between males and females?
females is smaller which can lead to impingement on the ACL
What two hormones are causes for higher ACL injury rate?
estrogen and relaxin
What happens at distal leg that can lead to ACL injury in females?
limited dorsiflexion can lead to pronation as compensation which cause genu valgum
What is difference in landing mechanics in males vs females?
males- Gastroc - hammys then quads fire
females- opposite meaning females land with less hip and knee flexion
What planes do females use to decelerate?
frontal and transverse while men uses mostly saggital
Why is endurance training for female athletes important for quad and hamstring?
when these muscles are fatigued then anterior tibial translation is increased by 33%
What is typical MOI for PCL?
dash board, trauma usually a major knee injury with other structures involved
What special tests are used for PCL?
posterior drawer, posterior sag
What are treatment interventions for PCL?
edema and pain control, gait training, mobility and strength exercises, closed chain to promote stability
What should be avoided during PCL rehab?
kneeling
What special tests are used for MCL?
Valgus at 0 and 30 degrees
What can results of special tests for MCL and LCL tell you?
if pain at 0 degrees it could be ligaments or capsule injury
if pain at 30 likely ligament injury
Along with MCL what is usually also damaged?
ACL and meniscus
What are special considerations for conservative rehab for MCL?
normalize quad function, avoid valgus stress, PRE with tibial IR, dynamic stabilization and HIP strength
What is a common co morbidity with LCL injuries?
fibula head and peroneal nerve
same rehab as MCL except avoiding varus stress
What are the main structures of the PLC?
LCL- stabilizes varus 0-30 and assists with control of tibial ER
Popliteus- dynamic stability against tibial ER
Popliteofibular ligament- similar functions
What are other structures that could be consider part of PLC?
ITB, Bicep femoris, lateral gastroc, lateral joint capsule
What is main role of PLC?
augments PCL and helps prevent hyperextension, tibial ER and varus angulation through static and dynamic stability
What is typical MOI for PLC?
force to anteromedial knee, knee hyperextension, tibial ER with knee in flexion or hypertext.
What is PP for PLC?
varus thrust due to instability, hyperextension, foot drop due to damage to peroneal nerve
What are sensory and motor function for peroneal nerve?
sensory- 1st dorsal web space
motor- DF, EV, greta toe extension
What are major tests for PLC injury?
PL drawer, Dial test, ER recurvartum, varus test
What is ER recurvartum test used for?
suspected ACL and PLC injury
