Knee Joint, Tibiofibular Joints, Ankle Joint and Joints of the Foot Flashcards
Study the two femoral condyles and state which condyle:
(a) is wider transversely?
(b) has a longer antero-posterior tibial articular surface?
(c) is more curved?
(d) has a more prominent buttress?
(e) groove for insertion of the tendon of popliteus muscle?
(a) lateral condyle
(b) lateral condyle
(c) medial condyle (It has a more symmetrical curvature, while the lateral condyle has a sharply increasing radius of curvature posteriorly)
(d) lateral condyle
(e) lateral condyle
NOTE:
The popliteus muscle originates from the lateral condyle of the femur by a strong tendon called the popliteus tendon. This tendon courses in the groove for the popliteus muscle on the lateral aspect of the lateral femoral condyle. This muscle plays an important role in the gait cycle by initiating the flexion of the fully extended (“locked”) knee. Thus, the popliteus is referred to as the “key to unlock the knee”.
State the functions of the ACL.
● Prevent posterior displacement of the femur on a fixed tibia or anterior displacement of the tibia on the femur
● Limits posterior rolling of the femoral condyles on the tibial plateau during flexion
● Prevents hyperextension of the knee joint (this ligament is taut during knee extension)
● [Diagram] [Cadaveric image]
State the function of the PCL.
It is taut during knee flexion and prevents anterior dislocation of femur on tibia, and posterior dislocation of tibia on femur.
Name the superior and inferior attachments of the anterior cruciate ligament.
Superior: posteromedial surface of the lateral condyle of the femur
Inferior: anterior intercondylar area of the tibia
Name the superior and inferior attachments of the posterior cruciate ligament.
Superior: anterolateral surface of medial condyle of the femur
Inferior: posterior part of intercondylar area of tibia
Which ligaments maintain side-to-side stability of the knee joint?
Medial and lateral collateral ligaments
State the key function of the:
1. medial collateral ligament
2. lateral collateral ligament
- prevent valgus stability to the knee joint
- prevent excess varus stress and posterolateral rotation of knee
Which ligaments maintain anteroposterior stability of the knee joint?
The cruciate ligaments
Describe the points of attachment of the tibial (medial) collateral ligament.
Superiorly: the medial condyle of the femur, just below the adductor tubercle
Inferiorly: medial condyle and medial surface of the proximal part of shaft of tibia
Describe the points of attachment of the fibular (lateral) collateral ligament.
Superiorly: the lateral epicondyle of the femur
Inferiorly: the lateral surface of the fibular head
State the significance of the intercondylar eminence of the tibia with respect to the stability of the knee joint.
It helps to prevent the sideways slipping of the femur on the tibia.
State 5 factors that maintain the stability of the knee joint (other than the intercondylar eminence of the tibia).
- The strength and actions of the surrounding muscles and tendons
- The medial and lateral collateral ligaments maintain the side-to-side stability of the knee joint.
- The cruciate ligaments maintain anteroposterior stability.
- The iliotibial band helps in stabilizing a partly flexed knee.
- The menisci increase the concavities of the tibial condyles for better congruence with the femoral condyles.