Flashcards in 1. The Hip Joint Deck (23)
What type of joint is at the hip?
Ball and socket synovial joint
Which bones articulate at the hip joint?
Acetabulum of pelvis and head of femur
Name an intracapsular ligament of the hip.
Ligament of head of femur
Describe the location of the ligament of head of femur.
Runs from acetabular fossa to fovea of femur.
What structure does the ligament of head of femur enclose?
Branch of obturator artery - blood supply to femoral head during childhood.
Name the extracapsular ligaments of the hip joint.
1. Iliofemoral ligament
2. Pubofemoral ligament
3. Ischiofemoral ligament
Describe the location and function of the iliofemoral ligament.
- Runs from anterior inferior iliac spine to femoral intertrochanteric line.
- Prevents hyperextension of the hip joint.
Describe the location and function of the pubofemoral ligament.
Runs from superior pubic rami to femoral intertrochanteric line.
Prevents hyperextension and hyperabduction.
Describe the location and function of the ischiofemoral ligament.
Runs from body of ischium to greater trochanter of femur.
Prevents hyperextension and limits medial rotation.
Describe the arterial supply to the hip joint.
1. Mainly via branches of the profunda femoris arteries: medial and lateral circumflex arteries - anastomose at base of femoral neck to form a ring from which smaller retinacular arteries arise.
2. Artery to head of femur (mainly during childhood)
Why might avascular necrosis of humeral head occur?
1. Can occur in childhood after disruption of artery to head of femur - circumflex artery not fully developed to compensate.
2. Can occur in adults after disruption of circumflex arteries, e.g. Intracapsular femoral neck fracture.
Which nerves innervate the hip joint?
1. Femoral nerve (anteriorly)
2. Nerve to quadratus femoris (posteriorly)
3. Superior gluteal nerve (superiorly)
4. Obturator nerve (inferiorly)
Name 4 factors providing stability at the hip joint.
1. Acetabular labrum
2. Joint capsule
How does the acetabular labrum stabilise the hip joint?
- Fibrocartilaginous collar attached to margin of acetabulum.
- Increases depth of acetabulum, providing a larger articular surface.
How does the joint capsule stabilise the hip joint?
Attaches at the intertrochanteric line anteriorly - limits extension at the hip along with iliofemoral ligament.
(Posteriorly, lateral part of neck is extra-capsular).
How do ligaments stabilise the hip joint?
1. Anteriorly and superiorly by iliofemoral - prevents hyperextension (screws femoral head into acetabulum)
2. Inferiorly and anteriorly by pubofemoral - prevents overabduction
3. Posteriorly by weaker ischiofemoral
4. Accessory ligaments: transverse acetabular ligament - strengthens inferior portion of acetabulum where acetabular notch is.
How do muscles stabilise the hip joint?
Muscles (medial and lateral rotators) and ligaments work in reciprocal fashion to pull femoral neck medially into acetabulum.
- anteriorly where ligaments are stronger, medial flexors are fewer and weaker
- Posteriorly where ligaments are weaker, medial rotators are greater in number and stronger - pull head of femur into acetabulum
Which muscles mediate flexion of the hip joint?
2. Rectus femoris
Which muscles mediate extension of the hip joint?
1. Gluteus maximum
2. Biceps femoris - Long head
Which muscles mediate abduction of the hip joint?
1. Gluteus medius
2. Gluteus minimus
3. Deep gluteals
4. Tensor fascia latae
Which muscles mediate adduction of the hip joint?
1. Adductor brevis, longus & magnus
Which muscles mediate lateral rotation of the hip joint?
1. Obturator externus & internus
4. Quadratus femoris
5. Gluteus maximus