Chapter 122 - Ligamentous Injuries of the Knee Flashcards
what tunnel malposition does transtibial femoral tunnel preparation lead to in ACL reconstruction?
vertical tunnel placement
what does drilling the femoral tunnel NOT in hyperflexion put you at risk of?
posterior cortical blowout
when performing a double bundle reconstruction of the ACL what knee position should you fix each bundle in?
anteromedial bundle should be fixed in 30-40 degrees of FLEXION
posterolateral bundle should be fixed in full extension
what is the re-rupture rate for ACL reconstruction in the literature?
1-20%
what is the rate of contralateral ACL tear?
3-6%
who should NOT get an allograft acl?
young people who participate in cutting sports
clinical outcomes of double bundle ACL reconstruction?
no difference in clinical outcomes, double bundle = higher cost, longer surgical times
what is more common in BTB autografts than other types?
- more kneeling pain
- higher rate of return to elite level athletics than other autografts
when an ACL does get infected, what is the most common bacterial pathogen?
staph epi
what is the biggest risk factor for DVT following ACL?
previous blood clot
oral contraceptives
family history
chronic PCL injury leads to arthritis in what compartments?
patellofemoral and medial compartment
what indicates a positive quadriceps active test for PCL injury?
when the tibia translates anteriorly at 90 degrees of flexion with resisted knee extension (indicates the tibia is subluxated posteriorly at rest)
non-operative rehab for PCL injuries includes what?
isolated quadriceps strengthening
quadriceps/hamstring isometric co-contractions
**Isolated hamstring contraction, especially in flexion should be avoided
what is the most common ligament injured in the knee
MCL
most common injury associated with MCL injury?
ACL (95% of concomitant in jury)
meniscal injury
MCL resists what loads
valgus (especially at 30deg)
external rotation (especially in extension)
proximal MCL injuries
- more reliably heal non-operatively
- may have difficulty achieving full ROM
distal MCL injuries
- less likely to heal without surgery
- result in residual laxity
most common outcome of non-op management of grade II or III MCL injuries?
asymptomatic residual laxity
in concurrent ACL/MCL injury - timing of surgery
delay proportionally to grade of MCL injury to allow MCL to heal in
G1: 2-4 weeks
G2: 4-6 weeks
G3: 6-8 weeks
(also this is the return to sport time for isolated non-op MCL)
what degree of knee flexion should the graft be fixed for MCL recon, or should the repair occur in MCL repair?
30degrees flexion
popliteus restricts what?
anterior tibial translation, varus, and EXTERNAL rotation
combined ACL/LCL is more common than what?
isolated LCL/PLC injury
timing of lateral injuries - LCL, PLC, etc
acute - within 2-3 weeks
after 3 weeks, lateral/posterolateral structures are retracted and scarred
