Left anterior knee joint dislocation with tibia located anteromedially relative to the distal femur. Associated lipohaemarthrosis of the left knee joint. Comminuted avulsion fracture of the proximal left tibia at the site of biceps femoris insertion. The proximal tibiofibular joint is intact. No further lower limb or pelvic fracture.
Haematoma lateral to the left biceps femoris and left vastus lateralis. Further haematoma extends between the deep and superficial posterior compartments of the leg.
Injury to the left popliteal artery with a long segment of non-opacification. Non-opacification commences just distal to the origin of muscular branches which supply the left gastrocnemius muscle. Reduced calibre of the popliteal artery distally which re-opacifies secondary to collateral supply from the the inferior lateral geniculate artery.
High origin of the left anterior tibial artery at the level of the tibial plateau with non-opacification of the popliteal artery at this level. The proximal left anterior tibial artery faintly opacifies secondary to collateral supply, however absent opacification in the vessel is seen at the level of the middle third of the tibia. Re-opacification distally also secondary to collateral supply is thready with faint opacification of the proximal left dorsalis pedis.
Reduced calibre of the left tibioperoneal trunk which is supplied by collateral supply. Normal opacification of the left posterior tibial artery which is visible to the level of the midfoot. Normal opacification of the left peroneal artery which is visible to the level of the ankle joint.
The bilateral common iliac, external iliac, common femoral and superficial femoral arteries are normal.
Impression
1. Left anterior knee joint dislocation with associated lipohaemarthrosis. Avulsion fracture of the proximal left fibula.
2. Left popliteal artery injury with segment of absent opacification. The left anterior tibial artery opacifies secondary to collateral supply, however opacification is absent within the mid-portion and thready distal to this. Normal opacification of the left posterior tibial and peroneal arteries.