Conditions of the Knee Flashcards
what muscles cross the knee?
Anterior: quads, sartorius
Medial: adductors (magnus, longus, brevis), gracilis, obturator externus
Posterior: hamstrings
Describe the role the pes anserine group plays in protecting the knee
the pes anserine group includes muscles from each compartment of the thigh: gracilis (medial), sartorius (anterior), and semitendinosus (posterior). They attach to the medial proximal aspect of the tibia and protect against valgus forces.
What are the pillars of joint stability at the knee?
- Bony congruency: menisci increase congruency of the femoral condyles on the tibial plateau, patella stabilizes knee anteriorly (floating bone)
- Ligaments and capsule: ACL, PCL, and MCL are the three intracapsular ligaments that prevent anterior and posterior translation of the tibia, and valgus forces. The LCL attaches distally to the head of the fibula and protects against varus forces. Popliteal ligaments protect against hyperextension
- Muscles that cross the joint: quads protect PCL, hamstrings protect ACL
MCL tears
MOI: valgus w foot planted
S/S: depending on severity, empty end-feel w grade III, often ACL and meniscus are involved (MCL has some attackment to meniscus)
Treatment: PIER, grade-dependent, VMO stimulation via NEMS (VMO checks out and atrophies w knee injuries)
ACL tears
MOI: rapid change in direction + planted foot + valgus force + forceful medial rotation of tibia
S/S: intracapsular swelling, ‘pop’ may be heard, severe pain which diminishes, tenderness anterior tibial plateau
Treatment: ROM limiting device, success of surgery dependent on rehab (must strengthen hamstrings)
Gracilils
O: inferior pubic ramus
I: medial proximal tibia
A: adduction, knee flexion, medial rotation
Sartorius
O: ASIS
I: medial proximal tibia
A: hip and knee flexion, lateral rotation, abduction
Semitendinosus
O: ischial tuberosity
I: medial proximal tibia
A: hip extension, knee flexion
Why should we do adductor strengthening following MCL tear?
Gracillis (pes anserine) is an adductor and protects against knee valgus
Why do MCL tears happen more often than LCL tears?
Valgus forces more common in sports, LCL has more laxity since it attaches to the head of the fibula + can handle force a little better
Menisci Ruptures
MOI: twisting/ fixed foot w asymmetrical WB
S/S: swelling, ‘catching’, recurrent swelling w activity, positive McMurray’s
Treatment: PIER, non-invasive surgery
Types of meniscal tears
- longitudinal
- bucket handle
- transverse
4.parrot beak
Why are medial meniscal tears more common than lateral?
- the coronary ligament of the medial meniscus is tighter and does not handle torsion very well.
- follows the trend of more MCL injuries
Patellofemoral Pain Syndrome
Any condition causing pain in patellar region; often due to tracking issues
Why does a steeper Q angle increase the risk of ACL tears?
the angle of the femur causes the MCL to bear more load as the knee is in a little more valgus than it should be. Valgus forces place more tension on ACL.
Describe the “Terrible Triad” or the “Queasy Quartet”
TT: Valgus force + torsion (MCL + meniscus, ACL)
QQ: add in pinching injuries to lateral meniscus
Patellar tendonitis
MOI: repetitive extension injuries + repetitive heavy eccentric loading
S/S: pain, patellar tracking issues (VMO vs vastus lateralis battle)
Treatment: PEIR, rest/rehab, appropriately prescribed exercise: stretch + address imbalances, eccentric rehab focus
IT Band Syndrome
MOI: IT band repeatedly rubbing over lateral epicondyle
S/S: increase pain w activity, pain w resisted knee extension (VL and IT band are connected)
Treatment: stretch TFL and IT band fascia, address mechanics, PIER
