Most Imp. technical consideration at the time of doing below knee amputation is -
Ans. is 'a' ie. Post flap should be longer than the anterior flop Posterior flap should be longer than the anterior flap as the posterior skin has a good blood supply (and anterior skin has poor due to lack of muscle on anterior aspect). A good blood supply helps in easy healing of stump. - Equally sho anterior and posterior flaps are used only when the long post flap technique is not feasible because of previous wounds or extensive tissue ischemia. 'The longer (the stump) the better', is the general rule for amputation at all sites, but below knee amputation is an exception. The amputation level is kept proximal to the lower third of tibia, since the preponderance of tendinous structures in the lower third predispose to poor circulation and an unstable painful lump. The best level below the knee as, for, as prosthetic fitting is concerned is at the distal musculotendinous junction of the gastrocnemius muscle. Some other imp. points about BK amputation The fibula is transected slightly above the tibial level. No essential differences in healing rate is noted in pts. with or without popliteal pulses, but the absence of a femoral pulse is associated with a high failure rate for BK amputation. The nerves are pulled gently down, transected and then allowed to retract, and the vessels are ligated above the level of the end of tibia.
Post. flap should be longer than the anterior flap
Stump should be long
Stump should be sho
Ant flap should be longer than post flap