see also [[Knee soft tissue injury]], [[Neurovascular assessment]] see : [tintinalli - knee dislocation](x-devonthink-item://4DC06646-5810-41FF-BA6D-8ECCEF6431E7?page=89), [Rosen - knee dislocation](x-devonthink-item://BDD7DC9A-394E-4DE4-89FD-5FFE9E8DBEE5?page=6), and [Dunn - knee dislocation](x-devonthink-item://D9DA78EE-40C7-4C1E-89C9-4F61C823DC41) > don't confuse knee dislocation complications with [[Supracondylar humerus fractures#Complications|supracoundylar humerus complications]] > [!key points] > - *popliteal artery injury* - must ==restore circulation <8 hours==. measure distal pulses and ankle-brachial index > - *peroneal nerve injuries* (stretch or rarely transection). > - deep peroneal nerve → sensation to first dorsal web space of toes and allows dorsiflexion of foot and extension of toes. injury: *foot drop and gait difficulty* > - tibial nerve injury - weakness of posterior compartment of leg muscles, weakness of intrinsic foot muscles, paraesthesia of skin to sole of feet > - popliteal vein: swelling/bruising popliteal fossa and swelling lower leg > - often associated with [[tibial plateau fracture]] **hard and soft signs of vascular injury to knee** | hard signs | soft signs | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- | | - lack of distal pulses<br>- thrill<br>- pulsatile haemorrhage<br>- expanding haematoma<br>- 5 ps (pain, pallor, parasthesia, poikloiothermia, paralysis)<br><br> | - decrease pulse relative to un-injured side<br>- significant haemorrhage<br>- non-expanding haematoma<br>- peripheral nerve deficits | **indications for CTA** - confirmed dislocation - suspected spontaneously reduced dislocation - multiple ligamentous injuries/laxity - potentially unstable bony injuries ot knee - large knee effusion - reduced distal pulses - abnormal [[Ankle Brachial Index (ABI)]] **management** - reduce dislocation - trauma slab at 15-20 deg and ability to do neurovascular obs - **may need to go right to theatre** if: ==absent pedal pulses, cool, mottled foot, expanding popliteal haematoma, or popliteal haemorrhage== - observe for asymmetrical pedal pulses and dorsilateral foot/leg paresthesias - CTA (historically all got them) - measure [[Ankle Brachial Index (ABI)]] → <0.9 concerning - observe for 24 hours - posterior splint - pedal pulse check every 2-3 hours *popliteal fossa anatomy* ![[Pasted image 20240820145237.png]]