soft tissue knee injuries Flashcards
What do menisci do?
distribute load from convex femoral condyles to relatively flat tibial articular surfaces
Lateral an medial menisci are fixed T/F
F
Medial meniscus is fixed while lateral meniscus Is more mobile
MCL resists valgus stress T/F
T (its rupture may lead to values instability)
LCL resists valgus stress T/F
F- it resists varus stress
ACL resists anterior _____ of the tibia and _____ rotation of the tibia in extension
subluxation
internal
(its rupture may lead to rotatory instability)
PCL resists _____ subluxation of the tibia i.e. anterior subluxation of the femur and hyperextension of the knee
posterior
its rupture may lead to various and rotatory instability
who are meniscal tears usually found in?
usually sporting injuries in younger patients or getting up from squatting position in younger patients
(can get atraumatic spontaneous degenerative tears in older patients -over 40)
What should you investigate a meniscal tear with?
MRI
Lateral meniscal tear is 10 times more common than medial T/F
F- medial meniscal tears approx 10 times more common than lateral meniscal tears
Meniscal tears heal very well T/F
F
only peripheral 1/3 has a blood supply
radial tears won’t heal
When should arthroscopic repair be considered?
In acute peripheral tears in younger patients Mechanical symptoms (painful catching or locking) for irreparable tears or failed meniscal repair
What does acute locked knee signify
displaced bucket handle meniscal tear
What is the management for acute locked knee?
urgent surgery required - may be repairable by arthroscopic repair
If knee remains locked- may develop FFD
If irreparable needs partial meniscectomy to unlock knee and prevent further damage
Degenerate meniscal tears are common T/F
T- 20% over 50s , many asymptomatic (injection may help)
What is the grading for knee ligament injuries
grade 1- sprain-tear some fibres but macroscopic structure intact
Grade 2-Partial tear-some fascicles disrupted
Grade 3-complete tear
some ligaments heal more than others and some stabilise over time
What is the treatment for MCL injury
brace, early motion and physio
Pain can take several months to settle
rarely requires surgery
What is the main stabiliser against IR of tibia
ACL
The best way to treat ACL rupture is repair T/F
F
ACL repair does not work- reconstruction only
autograft-patellar tendon or hamstrings
allograft-achilles
What is the ACL rupture rule of thirds?
1/3 compensate and are able to function well
1/3 can avoid instability by avoiding certain activities
1/3 do not compensate and have frequent instability or can’t get back to high impact sport
What is the role of surgery in ACL rupture
when the rotatory instability is not responding to physio
LCL injury is relatively uncommon. Where is it found?
varus and hyperextension
What is the management of complete rupture of the LCL ligament
need urgent repair if early (within 2-3 wks)
later–> reconstruction (hamstring or other tendon)
What causes a PCL rupture?
Direct blow to anterior tibia, or hyperextension injury
there will be popliteal knee pain and bruising
In 90% of cases PCL rupture is isolated T/F
F- isolated PCL rupture rare
A knee dislocation is a serious high energy injury. What are the high incidence complications?
Popliteal artery injury (tear, intimal tera and thrombosis)
nerve injury-common perineal nerve
compartment syndrome
What is the treatment for a knee dislocation?
Emergency reduction
re check neuromuscular status
What may cause a patellar dislocation
Rapid turn or direct blow
Patellar dislocation is more common in…
females adolescents ligamentous laxity valgus knee torsional abnormalities
What is the risk of recurrent dislocation in patellar dislocation?
10%
What is the management for patellar dislocation?
Some may benefit from surgical stabilisation-bony or soft tissue procedures
what is the likely soft tissue knee injury as a result of falling onto a flexed knee with quads contraction?
Extensor mechanism rupture
What are the RF for extensor mechanism rupture
previous tendonitis
steroids
chronic renal failure,ciprofloxacin
What does an extensor mechanism rupture practically look like?
Unable to straight leg raise
palpable gap
Getting from squatting - what is the most likely injury?
meniscal tear
Hypeextension- what is the most likely injury?
PCL
Varus- what is the most likely injury?
LCL
Valgus- what is the most likely injury?
MCL
Twisting- what is the most likely injury?
ACL or meniscal injury
Football injury, twist, pop, haemarthrosis, generalised pain, pain settles after a few days, rotatory instability. What is the most likely diagnosis?
ACL rupture
Getting up from squatting, sudden sharp pain medial joint line, effusion, recurrent medial pain & catching +/- locking. What is the most likely diagnosis?
Meniscal tear
