Anatomy Joints of the Lower Limb Questions and Answers — Questions and Answers
Question 1: A patient is unable to perform inversion and eversion of the foot following an injury. Damage to which of the following joints is most likely responsible for this deficit?
- Talocrural joint
- Subtalar joint (Correct answer)
- Distal tibiofibular joint
- Metatarsophalangeal joints
Correct answer: Subtalar joint
The subtalar joint, formed by the articulation of the talus and calcaneus, is primarily responsible for the movements of inversion and eversion of the foot. The talocrural (ankle) joint is a hinge joint mainly for dorsiflexion and plantarflexion.
Question 2: A football player sustains a severe lateral blow to the knee, resulting in the classic 'unhappy triad' injury. Which of the following structures is NOT part of this specific combination of injuries?
- Anterior cruciate ligament (ACL)
- Medial meniscus
- Lateral meniscus (Correct answer)
- Medial collateral ligament (MCL)
Correct answer: Lateral meniscus
The 'unhappy triad,' as classically described by O'Donoghue, involves simultaneous injury to the anterior cruciate ligament (ACL), medial collateral ligament (MCL), and the medial meniscus. Although subsequent studies have shown that lateral meniscus tears can also be common with ACL/MCL injuries, the classic triad specifically names the medial meniscus.
Question 3: Which of the following ligaments provides the primary passive support to the medial longitudinal arch of the foot by supporting the head of the talus?
- Long plantar ligament
- Plantar calcaneonavicular (spring) ligament (Correct answer)
- Deltoid ligament
- Short plantar ligament
Correct answer: Plantar calcaneonavicular (spring) ligament
The plantar calcaneonavicular ligament, also known as the spring ligament, is the key ligamentous structure that supports the head of the talus and, consequently, is the primary passive supporter of the medial longitudinal arch.
Question 4: The primary function of the anterior cruciate ligament (ACL) in the knee joint is to resist which movement?
- Posterior translation of the tibia on the femur
- Valgus stress at the knee
- Anterior translation of the tibia on the femur (Correct answer)
- External rotation of the tibia
Correct answer: Anterior translation of the tibia on the femur
The anterior cruciate ligament (ACL) is the primary ligamentous restraint preventing the anterior translation (forward movement) of the tibia relative to the femur. An injury to the ACL often results in significant knee instability.
Question 5: A patient is diagnosed with a fracture of the talus. This bone is unique because it articulates with all the following bones EXCEPT:
- Tibia
- Fibula
- Calcaneus
- Cuboid (Correct answer)
Correct answer: Cuboid
The talus articulates with the tibia and fibula superiorly (talocrural joint), the calcaneus inferiorly (subtalar joint), and the navicular anteriorly (talonavicular joint). It does not have a direct articulation with the cuboid bone; the calcaneus articulates with the cuboid.
Question 6: Which extracapsular ligament of the hip joint is considered the strongest ligament in the human body and is crucial for preventing hyperextension while standing?
- Ischiofemoral ligament
- Pubofemoral ligament
- Ligamentum teres
- Iliofemoral ligament (Correct answer)
Correct answer: Iliofemoral ligament
The iliofemoral ligament, also known as the Y-ligament of Bigelow, is an exceptionally strong ligament on the anterior aspect of the hip joint. Its primary function is to limit and prevent hyperextension of the hip, providing stability during standing and walking.
Anatomy Joints of the Lower Limb Questions and Answers
A patient is unable to perform inversion and eversion of the foot following an injury.
Damage to which of the following joints is most likely responsible for this deficit?