Ligament injuries to the knee Flashcards
MOI for MCL injury
valgus stress to the knee
Physical exam of MCL
Valgus stress test at both 30 degrees of flexion and at 0 degrees.
Grade 1 sprain: 5 mm
Grade 3 sprain: >10mm
MOI for LCL injury
varus stress to the knee
Physical exam of LCL
Varus stress test at both 30 degrees of flexion and at 0 degrees.
Grade 1 sprain: 5 mm
Grade 3 sprain: >10mm
Tx of MCL and LCL injuries
Rest, ice, immobilize
Non operative care for MCL and grade 1 or 2 LCL
Refer if there is a severe injury with instability or a refractory case (don’t improve within a normal timeframe)
MOI for ACL injury
Hyperextension (tibia moving forward)
Marked internal rotation
What can be assoc. with ACL injury
Meniscus tear and MCL tear
What is a big inspection finding with ACL or PCL ligament tears
Hemarthrosis (swelling of the knee immediately after tearing) due to the high vascularization of the cruciate ligaments
Physical exam of ACL injury
Lachman’s test (Most sensitive)
Anterior Drawer test (less helpful)
ACL tx
Initial: rest, ice, immobilization, crutches, qua/hamstring strengthening
Refer to ortho especially with young active pts.
Replace with autograft or allograft (patellar or hamstring tendon)
MOI for PCL injury
hyperflexion of the knee (isolated PCL injury)
“Dashboard” injury (occurs in MVA)
Fall on flexed knee with plantarflexion
Hyperextension of knee, severe ACL tear
Evaluation of PCL injury
Check popliteal artery and other soft tissues
Initial: Effusion and decreased ROM
Posterior Drawer Test
Posterior Sag Sign
PCL tx
Conservative tx
Can have surgery if other injuries occurred or in young, active pts