S3: the lower limb (1) Flashcards
What three bones form the hip bone?
Ischium
Ilium
Pubis
What type of joint is the hip?
Ball and socket synovial joint
Articulation between the head of the femur and acetabulum
Name the intra and extracapsular ligaments of the hip joint (+ the movements they prevent)
Intracapsular = ligamentum teres Extracapsular = iliofemoral, ischiofemoral and pubofemoral ligaments Iliofemoral = prevents hyperextension of the hip Pubofemoral = prevents excessive abduction and extension of the hip joint Ischiofemoral = prevents excessive internal rotation
Describe the factors that stabilise the hip joint
The cup-shaped acetabulum The acetabular labrum, which deepens the acetabulum The capsule The ligamentum teres The extracapsular ligaments The muscles surrounding the hip joint
Which muscles cause and assist hip flexion?
Cause = iliopsoas (iliacus + psoas major) Assist = rectus femoris, sartorius & pectineus
Which muscles cause hip extension?
Cause = gluteus maximus, hamstrings (semimembranosus, semitendinosus & long head of bicreps femoris)
Which muscles cause and assist hip abduction?
Cause = gluteus medius, gluteus minimus Assist = sartorius, tensor fascia lata
Which muscles cause and assist hip adduction?
Cause = adductor magnus, adductor brevis, adductor longus Assist = pectineus, gracilis, obturator externus
Which muscles cause and assist lateral rotation of the hip?
Cause = obturator externus, piriformis, obturator internus, superior & inferior gemelli, quadratus femoris Assist = gluteus maximus, sartorius
Which muscles cause and assist medial rotation of the hip?
Cause = anterior fibres of gluteus medius & minimus, tensor fascia lata Assist = adductor brevis, adductor longus, superior portion of adductor magnus, pectineus
What nerves is the hip joint innervated by?
Posteriorly = sciatic nerve Anteriorly = femoral nerve Inferiorly = obturator nerve
Describe the blood supply of the head of the femur
Mainly by the medial femoral circumflex artery in adults (intracapsular fracture carries a high risk of avascular necrosis of the bone)
In children = artery of the ligamentum teres is the major blood supply (in adults only a small part is adequately nourished by this due to epiphyseal fusion)
What are the branches of the lumbar plexus and their nerve roots?
Ilioinguinal – L1 Genitofemoral – L1, L2 Lateral femoral cutaneous – L2, L3 Obturator – L2, L3, L4 Femoral – L2, L3, L4 ‘I got leftovers on Friday’
What are the branches of the sacral plexus and their nerve roots?
Superior gluteal – L4, L5, S1 Inferior gluteal – L5, S1, S2 Sciatic – L4, L5, S1, S2, S3 Posterior femoral – S1, S2, S3 ‘Salmon is so pink’
Indicate the safe sites for intramuscular injection in the gluteal region
3-7 years old = dorsogluteal site
>7 years old = ventrogluteal site is preferred (further from neurovascular structures but requires better patient compliance)
To locate the ventrogluteal site, you should place the palm of your hand over the greater trochanter of the femur, point your thumb towards the inguinal region and your index finger toward the anterior superior iliac spine
Spread your index and middle fingers to make a V and carefully inject between the hand joints into the patient’s gluteus medius muscle
