Below Knee Amputation (Maham Rahimi, MD, and Erica Xue, MD)

this video shows a below-the-knee amputation for a patient with dry gangrene of the right foot the desired tibial bone length is marked approximately four finger breaths or around ten centimetres below the tibial tuberosity the skin incision is marked 1 to 2 centimetres distal to this transverse marking envelops the anterior two-thirds of the leg the posterior flat markings are extended medially and laterally as distally as possible ensuring enough soft tissue coverage for the BKA stump later the skin is incised with a 10 blade down to the fascia

circumferentially the fashion and muscles are further divided using electric cautery down to bone here the muscles of the anterior compartment such as the tibialis anterior extensor hallucis longus and extensor digitorum longus are divided and the anterior compartment the anterior tibial pedicle is encountered proximal and distal control of the anterior tibial pedicle are obtained with hemostats on the proximal end a stick tied with 3o silk to ensure hemostasis of the vessel

the distal end can be freely tied as this part of the leg will be removed the muscles are further divided off the tibia and fibula to separate bone from muscle a laparotomy pad is passed through the space and can be used to further bluntly dissect off the periosteum from the tibia and fibula by pushing proximally Bovie cautery can also be used here for a particularly tough connective tissue an oscillating bone saw is used to create the tibial osteotomy

And bevel the anterior tibial surface and corners removing sharp and rough edges a bone cutter is used to push the soft tissues as proximately as possible the bones are now completely separated an amputation blade is used to free the posterior flap from the bones and interior soft tissue here you can see that there is plenty of soft tissue coverage over the bone bleeding vessels are identified and tied off including the posterior tibial artery here which is being ligated with a silk tie next the tibial nerve is identified injected with 1% lidocaine which is not shown the tibial nerve

you can see is placed on traction suture ligated and cut when the holding suture is cut you can appreciate the nerve retracting which helps avoid neuroma formation the BK stop is irrigated copiously with warm saline removing any clots for final hemostasis before closure the fashion dermis are reapply Crowell and the skin with staples it is important to leave a few millimeters distance between dermal sutures to avoid ischemic necrosis of the skin here at some institutions a sub threshold rain may be left the incision is stressed with xeroform and abd pad and racked with kerlix the stressing is removed on post-operative day too