Ch 4 - MSK: Knee Pathology Flashcards
What are meniscal injuries associated with?
Cutting maneuvers
Tibial rotation w/ knee partially flexed in WB
What sports are medial meniscal injuries associated with?
Football
Soccer
What sports are lateral meniscal injuries associated with?
Squatting
Wrestling
What is the clinical presentation of an acute meniscal tear?
– Pop after an incident
– May cause true locking
– Effusions ~24 hours
– Knee stiffness
What is the most common MOI for posterior horn meniscal tears?
Valgus and ER
What is the clinical presentation of a degenerative meniscal tear?
– Minimal trauma
– >40 yo
– Impingement episodes may be minimal
What is seen on physical exam in meniscal injury?
Dec ROM
Effusion limits flexion
Meniscal fragment limits extension
Medial/lateral joint line tenderness
What is the gold standard for diagnosing meniscal tears?
MRI
– Sagittal views will best show the anterior and posterior meniscal horns
– Coronal views are the best views for the meniscal body
How do meniscal tears appear on MRI?
Line of increased signal extending from articular surfaces
What is the treatment of an inner 2/3 meniscal injury?
Surgical resection because of avascularity and resultant poor tissue healing
WBAT 1-2 day post op
What is the treatment of an outer 1/3 meniscal injury?
Repaired due to better vascular supply
NWB 4-6 weeks
Strengthening at 6 weeks
What is the most common ligament injured in athletics?
ACL
Soccer
Football
Downhill skiing
What is the MOI for ACL injury?
Cutting, deceleration, and hyperextension of the knee
Valgus force to a flexed and rotated knee
Noncontact injuries MC
What is the terrible triad?
ACL, MCL and medial meniscus injury
What is the clinical presentation of an ACL injury?
– Sudden pop, anterior knee pain w/ posterior lateral joint line pain
– Instability of the knee
– Swelling ~24 hours, and significant effusion
What is seen on exam in an ACL injury?
– Effusion
– Tenderness is variable
– +/- anterior drawer test
– Lachman’s test may be positive or can yield a false negative in approximately 10% of cases. It is examiner dependent and also influenced by muscle guarding.
What can be seen on X-ray in ACL injury?
Avulsion fx of tibial insertion of the ACL or the lateral capsular margin of the tibia
What is the accuracy of MRI to detect ACL tear?
85-90%
What is the initial treatment for ACL injury?
Partial WB, ice, and compression are used while evaluation is ongoing
What is the treatment after ACL reconstruction surgery?
– Partial WB
– Flex ROM 1st 2 wks
– Progress to closed chain kinetics
– Avoid open chain exercises
– Resistive exercises b/w 0° and 45° flex avoided 3 to 6 mo
– Lenox Hill derotation orthosis controls knee axial rotation, AP and medial–lateral control
– Sports-specific exercises 6 to 12 wks
– Complete rehab in 6 mo-1 yr w/ max ROM, strength, and agility
What is the MOI of a PCL injury?
- MCC is impact to the front of the tibia with the knee flexed
- Athletics: hyperflexion
What is the clinical presentation of a PCL injury?
– (+/-) pop
– Swelling inc ~24 hr
– Impaired extension
– (+/-) pain w/ WB
What is seen on exam in PCL injury?
– Effusion
– Popliteal tenderness
– (+/-) Posterior drawer test and sag tests
What can be seen on x-ray with PCL injury?
Avulsion
What is the treatment of a PCL injury?
- Surgical repair if ligament is avulsed w/ tibial fragment
* Quadriceps strengthening
What is the most common injured ligament of the knee?
MCL injury
What is the MOI of MCL injury?
- Football and skiing
- Impact force to the lateral knee
- Sustained valgus force
What is the clinical presentation of a MCL injury?
– Pop
– Medial knee pain
– Complete tears may allow walking and running after initial pain
– Knee stiffness
What is seen on exam in MCL injury?
– Medial swelling/ tenderness
– Min effusion
– Medial instability on valgus stress testing
– Opening of 5 to 8 mm compared to the opposite side may indicate a complete tear
– Instability in slight flex 30° specific for MCL injury
– Instability in full extension: MCL and posterior capsule injury