Editing Lower extremity amputation operatives (section)

== '''Above-knee amputation''' ==

* Principles
** Divide femur at the junction of middle and distal thirds, or approximately 12cm proximal to the condyles
** If necessary, division can be more proximal as long as tissue coverage exists
** Aim for equal anterior and posterior flaps
** There is a tendency for the hip flexors to abduct and flex the hip because the adductors are not attached, and therefore can't oppose it. These muscles need to be detached from the femur.
* Technique:
** Consider tourniquet, unless doing it for ischaemia
** Prep leg with U drape underneath and stockinette on foot
** Mark thigh - divide femur at junction of middle and distal thirds, with the corners of the fish mouth at the same level, and the distal extent of the flap as far as possible
** Fish-mouth incision (see below)
** Dissect through subcutaneous tissue with diathermy (watch out for GSV medially - ligate)
** Divide muscle with diathermy, leaving medial to last
*** Remaining gracilis, sartorius, semimembranosus, and semitendinosus are divided approximately 1-2cm distal to the point of transection of the femur.
*** Detach quadriceps proximal to the patella, leaving some of the tendinous portion intact. Reflect the vastus medialis laterally off the intermuscular septum to expose the adductor magnus, and sharply divide it off the medial epicondyle, and it is reflected medially to expose the femoral shaft.
** Identify SFA bundle lateral/deep to sartorius. Transfix and ligate the vessels traversing the Hunter canal (SFA and femoral vein).
** Femur transected proximal to the corners of the fish-mouth incision using a mechanical saw. File back edges to smooth them as needed. 
*** Myodesis - optional (may benefit patients more likely to ambulate with a prosthesis):
**** Wrap adductor magnus over the end of the bone, with the femur held in maximal adduction, then anchored using the lateral holes.
**** Quadriceps muscles then wrapped over the end of the femur and anchored posteriorly.
** Sciatic nerve stretched, divided and allowed to retract.
** ?sciatic block/catheter
** 10Fr Blake's drain
** Closure - fascia with 2/0 Vicryl, skin with nylon if dirty or monocryl if clean
** Dressings - clear opsite, velband, crepe
* Post-op:
** See BKA section below
* Complications:
** See BKA section for full list
** Wound infection
*** Higher rate than BKA
*** Leave dressings intact for 5 days unless clinically compelled to remove them earlier.
** Inability to ambulate
*** <10% of elderly AKA ambulate effectively
** Mortality
*** 16%
*** One year survival approx 50%