Knee Flashcards
What are the 3 joints of the knee?
Medial tibiofemoral
Lateral tibiofemoral
Patellofemoral
What are the 4 ligaments?
Anterior cruciate ligament
Posterior cruciate ligament
Medial collateral ligament
Lateral collateral ligament
What is the role of the ACL?
To prevent internal rotation of the tibia.
What is the role of the PCL?
To prevent hyperextension and anterior translation of the femur.
Which menisci is most commonly injured?
Medial meniscus
What % of meniscal tears occur alongside an ACL tear?
Around 25%.
Which test can be used to assess for a meniscal injury?
Steinmann’s test
How does a meniscal injury present?
Will show effusion, joint line tenderness and pain upon tibial rotation.
An MRI can be used to confirm the diagnosis.
Why do meniscal repair procedures have a high rate of failure?
As area has a poor blood supply.
What surgical procedure is recommended in meniscal injuries?
Arthroscopic partial menisectomy
What type of injury is indicated by a positive anterior drawer test?
ACL rupture
What is Lachmann’s test?
When the femur is stabilised, and the lower leg is drawn forwards.
If excessive anterior translation of the proximal tibia, it is suggestive of an ACL injury.
What group are the only patients in which reconstruction of a ruptured ACL is considered?
Professional sportspersons
All others are recommended to await natural healing.
Rupture of all 4 knee ligaments is referred to as what?
Complete knee dislocation
This is a medical emergency as there is usually an accompanying neurovascular injury.
What complications are at-risk in a complete knee dislocation?
Thrombosis
Ischaemia (distally)
Compartment syndrome
What is compartment syndrome?
When pressure within muscles builds to dangerous levels, following long periods of ischaemia to the distal muscles.
What structures are referred to as the extensor mechanism of the knee?
Tibial tuberosity
Patellar tendon
Patella
Quadriceps tendon
Quadriceps muscles
What injury type may be associated with patellar tendon/quadriceps tendon rupture?
Heavy weight-lifting
What must not be given to treat extensor mechanism tendonitis?
Steroids - may cause rupture.
Which antibiotic group is associated with the development of tendonitis as a side-effect?
Quinolones (e.g. ofloxacin)
What test can be used to assess integrity of the extensor mechanism of the knee?
Straight leg test
What are potential causes of patellofemoral dysfunction?
Chondromalacia patellae
Adolescent knee pain
Lateral patellar compression syndrome
How may patellofemoral dysfunction present?
Anterior knee pain
Locking
Stiffness
How is patellofemoral dysfunction treated?
Physiotherapy in 90% of cases.
What injury may result from a leg forced into valgus?
MCL injury/tear
