Lower limb anatomy / fractures Flashcards
where does the femoral artery branch from
external iliac
where does the obturator artery branch from
internal iliac
what does the femoral nerve (L2-L4) supply
hip flexors and knee extensors
what does the obturator nerve (L2-L4) supply
medial muscles (the adductors)
nerve roots of sciatic nerve
L4-S3
where does the sciatic nerve supply
posterior thigh, and all muscles of lower leg and foot (splits into tibial and common perineal)
what is piriformis syndrome
where the piriformis muscle compress the sciatic nerve - get radicular pain, numbness and buttock tenderness
femoral shaft fracture damages which nerve / artery
femoral
what happens to the proximal segment in a femoral shaft fracture
gets pulled into external rotation by gluteus medius and minimus and then flexion by iliopsoas
complications of femoral shaft fracture
fat embolism, non union
how would a fat embolism present
resp signs (tachycardia, tachypnoea and hypoxia) and petechial rash and confusion
ABG - T1 resp failure
blood film - fat globules
CXR - diffuse bilateral pulmonary infiltrates
CTPA
how do you Tx fat embolism
supportive care but do prompt fixation to prevent it occurring
surgery for a femoral shaft fracture
IM nail
most common open fracture is
phalanx
Ix for tibial shaft fracture
full length AP and lateral Xray
MX of tibial shaft fracture
reduction and above knee backslab
IM nail
when might you have to do ORIF and plates in a tibial shaft fracture
if it is particularly proximal or distal
what causes a tibial plateau fracture (normally lateral)
high energy (jumping)
with any fracture what is is essential to assess for and SAY IN EXAM
assess for neurovascular problems
high risk of what in a tibial shaft fracture
compartment syndrome
if there is an associated fibula fracture with a tibia shaft fracture, what does the level of the fracture indicate
high energy will be at the same level and low energy will be at a different level
why would a tibial plateau fracture lead to rapid degenerative changes
as there is disruption of the articular surface
main complication of tibial plateau fracture
OA
in what direction does the hip normally dislocate
posterior
how is the hip held in a dislocation
adducted, internally rotated and shortened
timeframe to reduce the hip when it is dislocated in order to prevent avascular necrosis s
4 hours
what is a hip dislocation normally associated with and why
high energy force so normally has fractures too
pain in trochanteric bursitis exacerbated by what (pain typically over GT and will radiate down thigh)
external rotation
how to treat trochanteric bursitis
should resolve, advise avoid excessive adduction (crossing legs) and do some gluteal strengthening
most common site for a metatarsal stress fracture
2nd
damage to which peripheral nerve causes foot drop
common peroneal nerve (supplies anterior and lateral leg)
the deep peroneal nerve supplies muscles where
anterior leg
the superficial peroneal nerve supplies muscles
lateral leg
how is the superficial peroneal nerve normally injured
fracture of the head of the fibula
apart from common peroneal nerve injury, what else can cause foot drop
L5 radiculopathy (loss of ankle dorsiflexion)
which nerve supplies sensation to the sole of the foot
the tibial (medial plantar, lateral plantar and medial calcaneal)
what nerve supplies sensation to the top of the foot
the superficial peroneal, with the deep peroneal supplying the first webspace
which imaging modality is best for nerve injuries
MRI
what nerves makes up the sural nerve
the common fibular and the tibia nerve (no motor function but sensation to the lateral foot)
firstline pain Mx for peripheral nerve injury
NSAID (same as BNF guidance for back pain)
Mx of weber A
remain weight bearing in a CAM boot (controlled ankle movement) for 6 weeks
advise after hip fracture surgery
patient can immediately fully weight bear
compartment syndrome most commonly associated with
tibial shaft fractures and supracondylar fractures
what is a buckle fracture
in paeds - get a swelling of the cortex of a longbone due to incomplete fracture where the cortex is not breached, can be tx conservatively
what is an initial mx step in compartment syndrome
keep the limb at the level of the heart
firstline pain med for back pain
ORAL NSAID!!!
what is fat pad atrophy
we have a fat pad under our calcaneus. As we age/obesity/trauma this reduces which causes pain, especially when in bare foot
where is Mortons neuroma most likely to affect (pain and sensation of lump)
between third and fourth metatarsal
test of Mortons neuroma
pain elicited by deep pressure to intermetatarsal space of mulders click test (where the foot is manipulated)
Tx of Mortons neuroma
conservative –> good footwear, activity modification, NSAIDs, steroid injection
May do surgery if above does not work
first sign of compartment syndrome
parasthesia (pulselessness is a late sign)
what is a greenstick fracture
unilateral cortex breach
what nerves are responsible for the knee reflex and what is the significance of this
L2/3/4 –> so when one of these nerve routes are compressed –> the knee reflex is affected
L5 compression –> nerve root unaffected
when is VTE prophylaxis with LMWH started post surgery
after 6 hours
signs of avascular necrosis on Xray
flattening of the femoral head and crescent sign
pressure over what is diagnostic of compartment syndrome
40mmHg
Mx of compartment syndrome
1) fasciotomy
2) IV fluid resus as fasciotomy releases myoglobin –> AKI
3) if necrotic –> debride and amputate
for a flare of RA what is recommended
1) intraarticular steroids
2) IM or PO steroids
