knee Flashcards
where are the femoral condyles and epicondyles?
on the top of the femur on both the medial and lateral side
what are the two major structures of the patella?
- femoral sulcus
- patellar tendon
what are the 3 main joints in the knee
- tibio-femoral
- patello-femoral
- proximal tibio-fibular
what are the extra-articular ligaments?
MCL and LCL
which are the intra-articular ligaments?
ACL/PCL
what is the physiologic movement of the knee?
flexion and extension
how does the knee flex and extend (with respect to the condyles)
the femoral condyles roll on tibial plateaus
what is the accessory movement of the knee?
the tibial plateau spins and glides on the femoral condyles
what is the normal degree range of a Q-angle?
15-20
how is the Q-angle computed?
a line drawn from the center of the patella up to the ASIS is compared to a line from the patella to the tibial tubercle
what does a Q-angle of greater than 20 degrees indicate?
knock knees (genu valgum)
what does a Q-angle of less than 15 degrees indicate?
low legs (genu varum)
what are three conditions that could result in anterior knee pain?
- patellar tendinopathy
- chondromalacia patellae
- patellar dislocation/subluxation
what is the MOI of patellar tendinopathy?
eccentric loading through jumping/landing activities
what are signs and symptoms patellar tendionpathy?
-quad weakness
-pain when loading the quads
-point tender
what are 3 risk factors to patellar tendon-related injuries?
-limited dorsiflexion (ankle)
-muscle weakness of the glutes
-muscle tightness
how many stages are there when examining patellar tendon related injuries?
4
what is the first stage of symptoms with patellar tendon related injuries?
pain after activity without functional limitation
what is the second stage of symptoms with patellar tendon related injuries?
pain during and after activity without functional limitation
what is the third stage of symptoms with patellar tendon related injuries?
prolonged pain during and after activity with functional limitations
what is the fourth stage of symptoms with patellar tendon related injuries?
complete tendon tear or rupture that will require surgical repair
what does the “opathy” ending mean?
symptomatic
what does the “osis” ending mean?
degenerative changes
what do degenerative changes lead to?
a loss of tensile strength, mucoid present, and the tendon thickening
how to manage patellar tendon related injuries?
strengthen the quadriceps and strapping
what is osgood-schlatter’s disease?
a growth disorder that is common in adolescents
what occurs during osgood-schlatter’s disease?
an outgrow of bone from the tibial tuberosity; there could be an avulsion fracture (separation form the TT)
what is chondromalacia patellae?
degenerative softening or wearing away of the articular cartilage.
What forces cause chondromalacia patellae?
compression and shear forces
what is the MOI for chondromalacia patellae?
an excessive Q-angle, and abnormal tracking of the patella
what are signs and symptoms of chondromalacia patellae?
pain during quad activities and patellar motion
what occurs to the nerve endings with chondromalacia patellae?
there is irritation and exposure of the nerve endings on the undersurface of the patella
what are risk factors of a dislocation/subluxation of the patella?
excessive Q-angle, weakness of the quads, and loose ligaments
what are some MOIs of a dislocation/subluxation?
a direct blow to the knee and/or a quick start or cutting motion
what could occur as a secondary injury due to a dislocation/subluxation?
a tear of the medial retinaculum or medial patello-femoral ligament (MPFL)
what is the #1 benefit of patellar bracing?
it prevents abnormal tracking of the patella
what are secondary benefits of patellar bracing?
prevents lateral displacement and maintains normal sliding motion
what are common tibio-femoral joint injuries?
ligament tears and cartilage tears
what three ligaments tear the most with tibio-femoral joint injuries?
MCL, ACL, and PCL
what is the MOI for a MCL injury?
valgus loading of the knee in extension
true or false: MCL ligament injuries only occur through contact mechanisms?
false
True of false: the ACL is the primary restraint to valgus loading?
false, the MCL is the primary, but the ACL is secondary
what is the most frequently injured knee ligament?
the MCL
do you want to treat the MCL conservatively?
yes, PRICE protocol and then crutches to keep them off the knee for a while
what is the goal of the valgus stress test?
to open the medial compartment of the knee and to evaluate if there is any damage to the MCL or medial capsule
how does a prophylactic knee brace prevent injuries?
-lateral blows to the knee
-stresses are absorbed and directed away from the joint
-prevents valgus loading and extra strain on the MCL
are prophylactic knee braces effective?
no, they tend to interfere with performance
why is the ACL known as the “watchdog of the knee”
it is the major static stabilizer
what are the 3 MOIs for ACL injuries?
- valgus loading with tibial rotation
- anterior tibial displacement
- hyperextension
what is the terrible triad?
when 3 structures in the knee are damaged from one event occurring
what three things occur and lead to the terrible triad?
- valgus loading
- compression of postern-lateral tibio-femoral compartment
- tibial rotation and anterior displacement of the femur
does the ACL require surgery?
yes
Why do you not want a conservative management?
the knee would continue to give out and buckle, and this would cause additional damage to the joint.
What is the special ACL test to get for issues?
The Lachman
What is the golden period?
the period of time from the moment of rupture until the joint swells
how long is the golden period typically?
15-20 minutes
what is hemarthrosis?
joint inflammation followed by muscle guarding
true or false: women how higher rates of ACL tears than men
true
what are theories for why women show higher rates of ACL tears?
- excessive Q-angle
-progesterone decreases tensile strength of c-tissue
-they have slower muscle activation patterns
-genetic predispositions (weaker collagen)
what are the functions of the menisci?
they absorb and distribute loads, stabilize the joint, and are involved in proprioception
which meniscus is larger?
the medial one
Which medial meniscus is less mobile and torn more often?
the medial one
what is the MOI of a meniscus tear?
the knee is flexed and rotated
where is the location of most meniscus tears?
the posterior horn of meniscus
does the red zone or the white have the capacity to heal?
the red zone
what do meniscus tears tend to start as?
radial.
can the white zone heal?
no, it would start to degenerate
what is a meniscectomy?
a surgery used to remove loos fragments. They trim around the torn section
what is a repair when looking at a meniscus tear?
then the meniscus is sutured down to the tibial plateau
what are the two tests used for meniscus tears?
- Appley’s compression test
- McMurray’s test
does the PCL provide rotary stability for the knee
no
what gets inflamed for ITBFS?
the lateral synovial recess (bursae)
what is a bursae?
a fluid filled sac
