Neurovascular supply to lower limb Flashcards
what kind of joint is the hip joint and what movements can it do?
Hip joint= flexion, extension, abduction, adduction, circumduction movements
* Ball and socket synovial joint - highly mobile
Large volume of load, increased stability needs
what are the 3 extracapsular ligaments that support + stabilize the hip joint
- ishchiofemoral ligament= limits internal rotation and hip adduction with flexion
- iliofemoral ligament= is the strongest ligament in the body and attaches the anterior inferior iliac spine (AIIS) to the intertrochanteric crest of the femur= prevents hyperextension
*pubofemoral ligament= arises from the iliopubic ramus, the superior pubic ramus and the obturator crest of the pubic bone= prevents excess abduction + extension
what arteries supply vasculature to the head of the femur
The blood supply to the femoral head comes from three main sources, i.e. medial femoral circumflex artery, lateral femoral circumflex artery and small branch of obturator artery through intracapsular terminal branches which run parallel to the neck. Any femoral neck fracture disrupts the terminal blood vessels producing AVN {avascular necrosis }
what does the obturator artery branch into + what does it supply
anterior branch of obturator artery follows the inner margin of the inferior pubic ramus to anastomose with the posterior branch of femoral artery and medial circumflex femoral artery. It supplies the obturator externus muscle, hip adductors and the skin over the medial thigh
what kind of hip dislocation is more common and why
Posterior hip dislocations are the most common; as anterior has stronger ligament support
femoral head is displaced posteriorly P tears through postero-inferior part of the joint capsule (weakest point)
which fracture of neck of femur is more at risk of avascular necrosis
*intracapsular fractures [occur within capsule of hip joint] can damage medial femoral and circumflex artery can cause avascular necrosis (AVN) of femoral head
- extracapsular fractures [occur outside joint capsule] so blood supply to head of femur is intact (AVN is rare complication)
the inguinal ligament is a landmark to find which artery?
The femoral artery can only be palpated below the inguinal ligament at the mid-inguinal point. The inguinal ligament is rounded and oblique laterally.
Mid-inguinal point - where external iliac becomes femoral
femoral vessels are the most commonly injured vascular structure (almost 70% of injuries), what is located in the femoral triangle?
femoral triangle:
superior border= inguinal ligament
lateral border= sartorius muscle
medial border= adductor longus
this triangle contains (lateral to medial)
-Nerve (femoral nerve
-Artery (femoral artery)
-Vein (femoral vein)
-Lymphatics (inguinal lymph nodes)
within what ligament is the artery to the head of the femur
ligamentum teres/ligament to head of femur
ligamentum teres artery descends from the posterior branch of the obturator artery and attaches at the fovea. This artery is commonly disrupted with dislocations. It is the main blood supply to the femoral head in children.
What artery + nerve supplies the anterior thigh?
what movement is anterior compartment of thigh responsible for?
femoral artery +femoral nerve (L2-L4)
= ANTERIOR THIGH (aka quadriceps)
anterior compatment;
-extension of knee
-flexion of hip
what artery + nerve supplies posterior thigh
what movement is posterior compatment of thigh in charge of?
the muscles of the posterior thigh aka hamstrings
- inferior gluteal artery, profunda femoris artery, perforating branches of the deep femoral artery
*sciatic nerve (L4-S3)
posterior compatment of thigh is in charge of knee flexion and thigh extension
what artery + nerve supplies medial thigh
what movement is medial compartment of thigh responsible for
medial thigh muscles are innervated by the obturator nerve (L2-L4) + obturator artery
Medial compartment = adductors
* **Adduction of hip **
the anterior tibial artery is a branch of the popliteal artery and becomes the [] in the foot
the anterior tibial artery is a branch of the popliteal artery and becomes the dorsalis pedis artery in the foot
which veins are at highest risk of becoming varicose?
Any vein that is close to the skin’s surface, called superficial, can become varicosed
such as the great + small saphenous vein (both are superficial)
varicose veins= the valves lose integrity and blood pools here, so the vein walls become weakened
what is the sensory supply to the lateral leg vs medial leg (dermatome)
lateral leg =L5
medial leg= L4
what spinal nerve is responsible for patellar reflex
L2-L4 spinal nerve
The patellar reflex is a deep tendon reflex, mediated by the spinal nerves from the levels L2, L3, and L4 in the spinal cord, predominantly in the root L4
The greater and lesser sciatic foramens are separated by the [] ligament
The greater and lesser sciatic foramens are separated by the sacrospinous ligament
what movements are lost in a femoral nerve palsy?
paralysis of quadriceps (instability of knee)=
no extension of knee
no flexion of hip
sensory loss of anterior thigh + medial leg
as anterior compartment is innervated by femoral nerve!
causes of femoral nerve palsy;
-compression (treatment for congenital hip dysplasia)
-pelvic fractures
-anterior hip dislocations
the sciatic nerve runs inferiorly to which muscle?
sciatic nerve (L4-S3) runs inferiorly to piriformis
what artery crosses the medial malleolus
posterior tibial artery crosses the medial malleolus
what are some of the causes of a tibial nerve palsy– what kind of paralysis + sensory loss does it cause
causes:
-fracture of tibia
-compression of tarsal tunnel
paralysis of plantar flexors; so no invertion of foot, no toe curling, no foot flexion
sensory loss to back of leg + sole of foot
what nerve innervates the lateral compartment of leg
what nerve innervates the anterior compartment of leg
common fibular nerve (responsible for dorsiflexion + eversion) has 2 branches deep + superficial
superficial fibular nerve innervates the lateral compartment of leg
deep fibular nerve innervates anterior compartment of leg
N.B. the common fibular nerve wraps around the neck of the fibular, and so any fractures of the fibular neck can cause nerve palsy. common fibular nerve damage will mean; loss of dorsiflexion + eversion of foot, as well as sensory loss to the dorsum of foot
in a sciatic nerve palsy, what kind of sensory loss + paralysis will patient present with + what are some of the causes of sciatic nerve palsy
Sciatic nerve is higher up in gluteal muscle fibres (just under piriformis)
cause of sciatic nerve palsy= posterior hip dislocations
- Foot drop when sat down
- Muscle wasting of:
- Hamstrings
- Calves (gastrocnemius and soleus)
Dorsiflexors
Patient looses ability to plantarflex and dorsiflex and there is muscle wasting + loss of achilles reflex
what are the 3 gluteal muscles and their action
the gluteal muscles are powerful hip extensors!
gluteal muscles; gluteus maximus, gluteus medius, gluteus minimus
piriformis is a powerful [] rotator
piriformis is a powerful lateral rotator
what does a positive trendelenburg sign indicate?
- +ve Trendelenburg sign indicates weakness in hip abductor muscles - gluteus medius/minimus (innervated by superior gluteal muscle)
- +ve sign - contralateral pelvic drop during single leg stance on affected side
this indicates its a potential superior/inferior gluteal nerve lesion - Tested by asking patient to raise left foot - left pelvis want to drop but right gluteus medius/minimus contract to elevate right pelvis - balances out (norm)
- If damaged - patient raises left foot, pelvis on right side moves up and pelvis on left side drops - damage to right superior gluteal muscle
where are intramuscular injections carried out + where exactly on the thigh
several possible locations for administering intramuscular injections, including the shoulder, hip, and thigh
Should be done on right upper lateral quadrant (superloateral) aka top side of bum; since it is superior to sciatic nerve
damage to which nerve causes foot drop and why is this dangerous?
common cause is damage to COMMON FIBULAR NERVE aka peroneal nerve. Foot drop is an inability to lift the forefoot (no dorsiflexion) due to the weakness of dorsiflexors of the foot. This, in turn, can lead to an unsafe antalgic gait, potentially resulting in falls.
antalgic gait= an abnormal pattern of walking secondary to pain that ultimately causes a limp, whereby the stance phase is shortened relative to the swing phase.
