Cortex- Pelvis and lower limb trauma Flashcards
what forms the pelvic ring
sacrum, ilium, ischium, pubic bones
+ supporting ligaments
what do you usually get when the pelvic ring is disrupted in one place
fracture or ligamentous injury somewhere else in the ring (polo mint)
what arteries and nerves are at risk in pelvic injuries
internal iliac arterial system
pre sacral venous plexus
branches of the lumbo-sacral plexus
what are the three main pattern of pelvic injuries
lateral compression fracture
vertical shear fracture
anteroposterior compression fracture
describe a lateral compression fracture of the pelvis
occurs with side impact, one half of pelvis (hemipelvis) is displaced medially
what accompanies fractures through the pelvic rami or ischium in lateral compression fractures
sacral compression fracture or SO joint disruption
describe a vertical shear fracture of the pelvis
occurs due to axial force on one hemi pelvis (fall from height, rapid deceleration)
affected hemi pelvis is displaced superiorly
leg on affected side will appear shorter
what is most at risk in a vertical shear fracture
sacral nerve roots
lumbo sacral plexus
(major haemorrhage may occur)
describe an anteropsterior compression injury
open book fractures- can cause wide disruption of the pubic symphysis, pelvis opens like the pages of a book
what is the main worry in anteroposterior compression injuries
substantial bleeding from torn vessels occurs, as pelvic volume increases with displacement several litres of blood may be lost before tamponade and clotting occurs
what must be done promptly in anteroposterior compression injuries
reduction of the disaplcement to minimise the pelvic volume to allow tamponade of the bleeding to occur
fluid resus
Application of a tied sheet or a special pelvic binder around the outside of the pelvis will hold the reduction temporarily and allow clotting of the vessels.
An external fixator will provide more secure initial stabilization.
what might ongoing haemodynamic instability need in pelvic fractures
angiongram and embolization or open packing of the pelvis
why is a PR exam mandatory in pelvic injuries
assess sacral nerve root function and to look for the presence of blood
blood may indicate a retal tear- open fracture- higher mortality
why should catheterisation be done with caution in pelvic injuries
as patient may also have bladder and urethral injuries (blood at the urethral meatus), catheterisation may risk further injury
what do the majority of low energy pubic rami fractures tend to be
minimally displaced lateral compression injuries with sacral fracture or SI joint disruption posteriorly
conservative management
what can acetabular posterior wall fractures be associated with
hip dislocation
what are the mortality rates for hip fractures
10% at one month, 20% at four months and 30% at one year
why do most hip fracture patients undergo surgery despite the risks
risks of non‐operative management are just as high. With non‐operative management, prolonged bed rest for several weeks would be required during which time the patient would be very sore for toileting and bathing whilst they would be at very high risk of problems with recumbency (pressure sores, chest infections) and the fracture may not heal, muscular atrophy makes subsequent rehabilitation difficult. Therefore, to maximize the chance of restoration of function and to promote early mobilization almost all hip fractures undergo surgery within the first 24 hours unless time is required for medical optimization.
how many hip fracture patients return to their pre-injury function
30%
what is the relevance of intra/extra capsular hip fractures
likelihood of disruption of the femoral head blood supply
what is the blood supply to the femoral head
ring of anastomosis of the circumflex femoral arteries at the insertion of the hip capsule at the base of the femoral neck
what are the medial and lateral circumflex arteries branches of
profunda femoral artery
what is at risk when the blood supply to the femoral head is disrupted
AVN and non union of the fracture
how are intracapsular fractures more reliably treated
with replacement femoral head (due to possible disruption of blood supply) - hemi arthroplasty/ THR
who should get THR
in the higher function hip fracture patient
who should get hemi arthroplasty in intracapsular hip fractures
restricted mobility/ cognitively impaired (THR would have increased risk of dislocation)
how are extracapsular fractures fixed
hive high union rate so usually internal fixation with compression or dynamic hip screws
what fracture does a fixated extracapsular hip fracture usually heal in
a shortened position
when can stress fractures of the femoral shaft occur
in osteoporotic bone, metastatic disease, pagets disease, long term bisphosphonate (ironically for osteoporosis)
how much blood loss can occur in displaced femoral shaft fractrues
up to 1.5 litres
what can cause the symptoms of confusion, hypoxia and risk of ARDs in a displaced femoral neck fracture
fat from the medullary canal entering the damaged venous system- fat embolism
what is the management for a femoral shaft fracture
after initial resuscitation: femoral nerve block Thomas splint- stabilizes the fracture minimizing further blood loss and fat embolism
closed reduction and stabilization with an intramedullary nail however minimally invasive plate fixation with minimal disruption to the fracture site blood supply can also be used
what can cause true knee dislocations
high energy injuries, severe hyperextension, rotational forces
why is knee dislocation a surgical emergency
high risk of vascular injury (intimal tears, vascular occlusion, complete transection), nerve injury, compartment syndrome
how can you revascularise a knee
endovascular procedures or bypass
what is usually required to treat a knee dilocations
reduction nerve and vascular assessment revascularisation multi ligament repair external fixator if knee very unstable
what can cause a proximal tibia plateau fracture
high energy in young or osteoporosis in old
describe tibial plateau fractures
intra articular fractures with either a split in the bone, depression of the articular surface or combo of both
what is the aim of treatment of most intra articular fractures
surgery is usually required with the aim of reduction of the articular surface and rigid fixation with early motion to combat the risk of stiffness and post traumatic OA
what type of tibial plateau fracture might a valgus stress injury cause
lateral plataeu fracture with failure of the MCL and possibly ACL
what might a proximal tibial plateau fracture caused by e.g. a car bumper be associated with
injury to the common peroneal nerve with foot drop (loss of power to tibialis anterior)
what type of tibial plateau fracture might a varus stress injury cause
medial plateau fracture, potential for LCL rupture and stretch to the peroneal nerve
what is the treatment for tibial plateau fractures
Plates and screws are usually used for fixation. Once a depressed fracture has been elevated, a void in the bone is left requiring bone grafting (usually morsellised packed cancellous autograft from the iliac crest) to provide support.
often need TKR
how do tibial shaft fractures usually occur
with indirect force + either bending (transverse fracture), rotational energy (spiral fracture), compressive force from deceleration (oblique fracture), or a combination- high energy (comminuted fracture)
what is the commonest cause of compartment syndrome post trauma
tibial shaft fractures (particularly anterior compartment)
when can tibial shaft fractures be treated non operatively
up to 50% displacement and 5 degrees of angulation
how are tibial shaft fractures non operatively treated
above knee cast
what way can tibial fractures drift
If the fibula is not fractured, the tibia often drifts into varus whilst if the fibula is also fractured valgus alignment is more common
how are tibial shaft fractures treated operatively
internal fixation
if comminuted or open require surgical stabilisation - usually intramedullary nailing (less disruption to periosteal blood supply)
how long do tibial shaft fractures take to heal
16 weeks to a year
what is a common side effect of intramedullary nailing of a tibial fracture
anterior knee pain- nail inserted behind patellar tendon
what might non unions require
bone grafting or special circular frames
what causes most ankle injuries
inversion/ rotational force on a planted foot
what are the lateral ankle ligaments
anterior and posterior talofibular ligaments and calcaneofibular ligament
what are the symptoms of a sprain of the lateral ankle ligaments
pain, bruising, mild to moderate tenderness
what criteria determines the likelihood of a broken ankle and the need for xray
ottawa
what merits an x ray for a ankle injury
severe localised tenderness (bony tenderness) of the distal tibia/ fibula
inability to bear weight for four steps
what are stable ankle fractures
treatment is walking cast or splint for 6 weeks e.g. insolated distal fibular fracture with no medial fracture/ rupture of the deltoid ligament
what is an unstable ankle fracture
usually required ORIF e.g. distal fibular fractures with rupture of the deltoid ligament
or
bimalleolar fracture
what suggests rupture of the deltoid ligament
bruising and tenderness medially
what is talar shift
asymmetric increased space around the talus within the ankle mortise
what is talar tilt
when talus and tibial plafond being non parallel
what does talar tilt and shift mean
the deltoid ligament must have torn (if there is no medial malleolar fracture)
what does talar shift/ tilt risk
post traumatic OA
what treatment is required for talar tilt
anatomical reduction and rigid internal fixation
what does gross talar shift result in
fracture dislocation
why may ORIF in ankle fracture be delayed 1-2 weeks
as associated with substantial soft tissue swelling and fracture blisters- allowed to settle to reduce the risk of wound healing problems and infection
what is a lis franc fracture
fracture of the base of the 2nd metatarsal with dislocation of the base of the 2nd metatarsal with/without dislocations of the other metatarsals (at the tarso-metatarsal joints)
what happens to the ligaments is a lisfranc fracture
The ligament from the medial cuneiform to the base of the 2nd metatarsal no longer holds the metatarsal in joint
how does a lisfranc present
grossly swollen, bruised foot- be aware of normal x ray - unable to weight bear
how do you treat a lisfranc
closed/open reduction with fixation using screws
what usually causes a fracture of the 5th metatarsal
inversion injury - results in an avulsion fracture at the insertion of the peroneus brevis tendon
what is the treatment for a metatarsal (2-5) fracture
walking cast, supportive bandage or wearing stout boot for 4-6 weeks
if multiple fractures stabilised with K wires
why are 1st metatarsal fractures usually fixed
as important to foot function
when are stress fractures seen on x ray
might not be seen until a callus response/ healing has begun
how are toe fractures treated
protection in a stout boot.
Intra‐articular fractures of the base of the proximal phalanx of the hallux may benefit from reduction and fixation if the fragment(s) are sizeable.
Open fractures require debridement and may be stabilized with a wires
how are toe dislocations treated
neighbour strapping or wiring
