Anatomy Exam Joints of the Lower Limb 2 — Questions and Answers
Question 1: Which structure forms the acetabular labrum's primary function in the hip joint?
- Deepens the socket and improves stability (Correct answer)
- Provides arterial supply to the femoral head
- Acts as the primary restraint against hip flexion
- Transmits weight from pelvis to femur
Correct answer: Deepens the socket and improves stability
The acetabular labrum deepens the acetabular socket, increasing joint congruency and stability while also creating a negative pressure seal.
Question 2: The zona orbicularis of the hip joint capsule is best described as:
- Circular fibers that grip the femoral neck (Correct answer)
- Longitudinal fibers reinforcing the anterior capsule
- A synovial fold covering the femoral head
- The thickened inferior portion of the iliofemoral ligament
Correct answer: Circular fibers that grip the femoral neck
The zona orbicularis consists of circular capsular fibers that encircle the femoral neck, helping retain the femoral head in the acetabulum.
Question 3: Which nerve is most at risk during a posterior surgical approach to the hip?
- Sciatic nerve (Correct answer)
- Femoral nerve
- Obturator nerve
- Superior gluteal nerve
Correct answer: Sciatic nerve
The sciatic nerve passes posterior to the hip joint and is the structure most at risk during posterior hip surgery or posterior hip dislocation.
Question 4: The ligament of the head of the femur (ligamentum teres) transmits which artery in adults?
- Obturator artery branch (Correct answer)
- Medial circumflex femoral artery
- Inferior gluteal artery
- Lateral circumflex femoral artery
Correct answer: Obturator artery branch
The ligamentum teres carries a branch of the obturator artery to the femoral head, though its contribution to femoral head vascularity is minor in adults.
Question 5: During hip abduction, which ligament becomes taut to limit excessive movement?
- Pubofemoral ligament (Correct answer)
- Iliofemoral ligament
- Ischiofemoral ligament
- Ligamentum teres
Correct answer: Pubofemoral ligament
The pubofemoral ligament, oriented horizontally, tightens during abduction and external rotation to limit excessive hip abduction.
Question 6: The hip joint's blood supply to the femoral head is primarily from which vessel?
- Medial circumflex femoral artery (Correct answer)
- Lateral circumflex femoral artery
- Superior gluteal artery
- Profunda femoris artery
Correct answer: Medial circumflex femoral artery
The medial circumflex femoral artery provides the dominant blood supply to the femoral head via retinacular vessels running along the femoral neck.
Question 7: Which movement at the hip joint is most restricted by the iliofemoral ligament (Y-ligament of Bigelow)?
- Hyperextension (Correct answer)
- Flexion
- Internal rotation
- Adduction
Correct answer: Hyperextension
The iliofemoral ligament is the strongest hip ligament and primarily limits hyperextension, allowing humans to stand upright with minimal muscular effort.
Anatomy Exam Joints of the Lower Limb 2
Which structure forms the acetabular labrum's primary function in the hip joint?