Knee Flashcards
What articulations occur at the knee?
Patellofemoral and tibiofemoral
Describe the landmarks of the distal femur
Medial condyle larger than lateral condyle, anterior intercondylar depression for patella articulation and posterior intercondylar fossa
Describe the difference between the lateral and medial menisci of the knee
Lateral connected to 2 ligaments allowing rotation, medial connected to tibial collateral ligament causing tears in trauma
Where do the cruciate ligaments originate and attach?
PAMs APpLes
Posterior originates at posterior tibia passes anteriorly and inserts medially.
Anterior originates at anterior tibia passes posteriorly and inserts laterally.
What are the functions of the cruciate ligaments?
Anterior prevents hyperextension
Posterior prevents hyperflexion
Which cruciate ligament is the main stabiliser in weight-bearing flexed knee?
Posterior
Which muscles stabilise the knee?
Vastus medialis and vastus lateralis
What occurs in knee locking and unlocking?
Femur rotates internally and is unlocked by rotating laterally by popliteus muscle.
What is the ‘unhappy triad’ and how is it caused?
Tibial collateral ligament, medial meniscus and anterior cruciate ligament injury caused by a blow to the side of the knee or lateral twisting
Describe how to perform the anterior and posterior drawer signs and what occurs in positive results for both.
Patient lays supine with hip flexed 45 degrees and knee flexed 80 degrees. Sit on foot to stabilise. Relax leg muscles (palpate posterior leg to check). Thumbs on tibia and push/pull. Excessive protrusion (anterior drawer) indicates ACL injury. Excessive depression (posterior drawer) indicates PCL injury.
Name a common way of damaging the posterior cruciate ligament.
Falling on a flexed knee
What is “housemaid’s knee”?
Prepatellar bursitis
What is “Clergyman’s knee”?
Superficial infrapatellar bursitis
What is a “Baker’s cyst”?
Abnormal fluid filled sac of synovial membrane in popliteal fossa due to chronic knee effusion
