Soft Tissue Knee Injuries Flashcards
Which meniscus is more flexible?
Lateral (the medial one is more fixed)
Purpose of menisci?
Distribute load from the convex femoral condyles to the relatively flat tibial articular surfaces
A valgus stress on the knee will damage…
MCL
A varus stress on the knee will damage…
LCL
What are the function(s) of the ACL?
1) Prevent anterior subluxation of tibia
2) Prevent internal rotation of tibia in knee extension
What are the function(s) of the PCL?
1) Prevent posterior subluxation of the tibia
2) Prevent knee hyperextension
Instability descending stairs and recurrent hyperextension suggest damage to which ligament?
PCL
Rotatory instability of the tibia suggests damage to which ligament?
ACL
In young patients, meniscal tears tend to be traumatic/atruamatic?
Traumatic
50% of ACL ruptures will also have what injury
Meniscal tear
What’s the imaging modality of choice for meniscal tears?
MRI
Most common area of meniscal tear
Medial
T/F: The meniscus generally has good healing potential.
False - only the peripheral 1/3rd of it has a blood supply. Radial tears will not heal at all.
Which surgery is useful in acute peripheral meniscal tears in young patients?
Arthroscopic repair
An arthroscopic menisectomy should be considered if what is present with meniscal tear?
Symptoms of locking or failed repair
An acute locked knee signifies what type of meniscal tear?
Bucket-handle tear
Degenerate tears are common in which group of patients?
> 50 (grey hair - meniscal tear)
Degenerate tears of the meniscus usually are the 1st indicator of which other disease
OA
What are the 3 grades of knee ligament injury?
Grade 1 = sprain
Grade 2 = partial tear
Grade 3 = complete tear
MCL tear treatment options
Brace, early motion and physio.
Most resolve very well without surgery.
T/F: ACL repairs are more common than reconstruction.
False - repairs usually don’t work, reconstruction is the mainstay
What tendons can be used in an ACL reconstruction?
Patellar or semitendinosus tendon. Achilles tendon (less similar).
What is the “rule of 1/3rds” in reference to ACL?
1/3rd do well, 1/3rd can avoid instability, 1/3rd get frequent instability
(younger patients more likely to have poorer outcomes)
What % of ACL injuries have to have surgery?
40%
What is the main indication for surgery in ACL rupture?
Rotatory instability not responding to therapy.
ACL reconstruction means how long in rehab?
3 months to 1 year
LCL injury commonly gives damage to which nerve?
Common fibular nerve
LCL tends to heal well by itself, T/F?
False - doesn’t heal well and often leads to varus and rotatory instability if not corrected
A direct blow to the anterior tibia OR a hyperextension injury is likely to damage which structure?
PCL
How is complete knee dislocation treated?
ORIF (emergency due to risk of compartment syndrome and common fibular nerve injury)
Risk factors for patellar dislocation (4)
1) Female sex
2) Adolescent age
3) Ligamentous laxity
4) Valgus knee
A fall onto the flexed knee with quadriceps contracted is likely to cause which type of injury
Extensor mechanism rupture
What are the risk factors for extensor mechanism rupture?
Tendonitis, steroids, chronic renal failure, fluroquinolones (ciprofloxacin)
Extensor mechanism rupture can be managed conservatively, T/F?
False - needs surgery to correct
Which ligament damage: valgus force?
MCL
Which ligament damage: twisting?
ACL or meniscal injury
Which ligament damage: varus?
LCL
Dashboard or hyperextension injury will damage which ligament?
PCL
Getting up from squatting will damage which structure?
Meniscus
Spot diagnosis: football injury, twist and pop, haemarthrosis, generalised knee pain, pain settles after a few days but rotatory instability present.
ACL rupture
Spot diagnosis: getting up from squatting, sudden sharp pain in medial joint line, effusion, recurrent medial pain & locking?
Meniscal tear (bucket handle-possible)
Which cartilage covers the surface of the bones in synovial joints?
Hyaline cartilage
T/F: Partial articular cartilage injuries will heal quickly.
False - only full thickness injuries tend to heal.
What is the underyling pathology of osteochondritis dessecans?
An area of the surface of the knee loses it blood supply and cartilage (plus bone sometimes) can fragment off.
Treatment of choice for osteochondritis dessecans?
Pinning if detaching
Will osteochondritis dessecans continue to progress to further injury?
Sometimes - can also heal or resolve spontaneously.
All cartilage regeneration techniques will heal with what
Fibrocartillage
Most common cartilage regeneration technique
Drilling
Contraindications to cartillage regeneration
Radiographic signs of OA, inflammatory arthritis, joint instability.
What’s a surgical treatment option for early knee OA?
Osteotomy - only if varus knee with pure medial OA.
Knee replacements should be given as early as possible in OA, T/F?
False - wait for end-stage arthritis.
What has a better success rate: partial or total knee replacement?
TKR
How long should a TKR usually last?
15-20 years
T/F: ACL reconstruction surgery involves drilling into the femur.
True
