Steps for Below Knee Amputation Surgery (Without Bone Bridge)
Following are the gross steps for doing a below knee amputation surgery, for detailed steps please check out these links ( Link1 and Link2 ) .Marking the incision for flap using following parameters
- Anterior incision 10cm distal to tibial tubercle
- Anterior incision 2/3 total circumference
- Posterior incision 1/3 total circumference
- Posterior flap should be distal to the musculotendinous junction of the gastrocnemius
- Round out the distal ends of the posterior skin flap to reduce redundancy of skin upon closure
Putting the Incision and Anterior Soft Tissue Dissection
- Incision is deepened in layers
- Saphenous vein is clamped and ligated;
- Anterior incision is then carried through all tissues to bone
- Now one can identify anterior tibial artery and veins, and deep peroneal nerve anterior to interosseous membrane; anterior neurovascular bundle can always be identified by spreading between the tibialis anterior and the EHL muscles
- Incision is carried out thru lateral compartment, superficial peroneal nerve is identified, ligated proximally and cauterized
Transection of Fibula
- Fibula is transected 1-2 cm proximal to the level of the tibial transection. Periosteum of the fibula is elevated proximally before transection
Tibial transection
- Periosteal layer of the tibia is cut sharply 1 cm distal to the level of the skin and elevated proximally about 1-1.5 cm, leaving a layer for suture of the posterior musculature
- Tibia is sectioned with power saw 1 cm distal to skin edge and anterior cortex is beveled obliquely
Posterior Flap Dissection
- Posterior muscle mass is sharply and carefully freed from its attachments to the tibia and fibula distally to the level of the posterior skin incision
- Posterior tibial artery & veins and the peroneal artery and veins are individually clamped and tied
- Tibial nerve is pulled, cut proximally and allowed to retract
- Deep muscles: tibialis posterior, FDL, FHL are transected just distal to the level of the tibia and allowed to retract;
- Soleus muscle is isolated and excised, leaving the gastrocnemius as sole muscle of the myocutaneous flap
- Sural nerve is pulled, cut proximally and allowed to retract
Myodesis
- Drill holes just anterior to the bone bevel for myodesis
- Use a locking style Krackow suture through the gastrocnemius aponeurosis and secure it to the tibia
- Place a submuscular drain
- Secure the borders of the gastrocnemius to the proximal anterior fascia
- Wound is closed in layers
- Soft dressing is applied
- Cast is applied to immobilize the knee to avoid a postoperative flexion contracture
