Soft Tissue Knee Injuries Flashcards
Radial fibres of the menisci can resist what?
Tears
What part of the meniscus has a blood supply
The outer third only - most is avascular
What is one of the main differences between the lateral and medial menisci?
The lateral is flexible and the medial is fixed
What do the knees pivot on
The medial compartment through flexion and extension
Why are medial meniscus tears more common than lateral?
It is under a greater amount of shear stress
MCL resists what type of stress
Valgus
LCL resists what type of stress
Varus
What does the ACL resist
Anterior subluxation of the tibia and internal rotation of the tibia in extension
What does the PCL resist
Posterior subluxation of the tibia i.e. anterior sublucation of the femur and hyperextension of the knee
Why do we usually expect the medial collateral ligament to heal
It has a great blood supply
Where does the lateral ligament run form and to where
From the lateral epicondyle to the fibular head
A MCL rupture may lead to what
Valgus instability
What might an ACL rupture lead to
Rotatory instability
What might a PCL rupture lead to
Recurrent hyperextension or instability descending the stairs
Multiligament injuries often require what
Surgery
Why will a radial tear not heal
Due to the lack of blood supply
What do Bucket- Handle tears cause
Locking of the knee
Who are at risk of having a meniscal tear
Young through sporting injuries or getting up form a squatting position.
Atraumatic spontaneous degenerate tears in older patients
50% of ACL ruptures also have what
A meniscal tear
What is the investigation of choice for knee ligaments
MRI
What is the point in operating on a meniscal tear when there is a 40% failure rate
You can still preserve the cartilage
What should be considered in a patient with mechanical symptoms with an irreparable tear or failed meniscal repair
Arthropscopic menisectomy
What does an acute locked knee signify
Displaced bucket handle meniscal tear
What is required for a Displaced bucket handle meniscal tear
Urgent Surgery
What is meant by a grade 1 knee ligament injury
Sprain - tear some fibres but macroscopic structure intact
What is meant by a grade 2 knee ligament injury
Partial tear - some fascicles disrupted
What is meant by a grade 3 knee ligament injury
Complete tear
What is the management for an MCL injury
Brace, early motion and physio
What ligament is the main stabiliser against Internal rotation of tibia
ACL
What can be done to help an ACL rupture
reconstruction only - autograft, allograft or donor tendon
What can an LCL cause
Varus and rotatory instability
If the LCL is completely ruptured what is required
Urgent repair
An isolated PCL rupture is common. True or False
False, it is rare (i.e. with another injury)
What are some of the complications of a knee dislocation
Popliteal artery injury
Nerve injury
Compartment syndrome
Patellar dislocation is more common in men, True or false
False - more common in women
what other groups are at an increased risk of a patellar dislocation
Adolescents
Ligamentous laxity
Valgus knee
torsinal abnormalities
What is the common presentation for an extensor mechanism rupture
Fall onto flexed knee with quads contraction
Unable to straight leg raise
Palpable gap
What does an extensor mechanism rupture require
Surgical repair
Twisting results in
ACL or meniscal injury
If there is a haemarthrosis, what does this indicate
ACL or fracture
If there is effusion, what does this indicate
Meniscal or chondral injury
