Analgesia following leg amputation is based on morphine administration. For elderly patients
of ASA physical status 2 or 3, morphine sparing is possible when perinervous block techniques
are used. Phantom limb pain complicates leg amputation in 50 to 80% of cases. Prevention of
these pains has been studied in various clinical trials but the interest of perinervous block
technique remains to be evaluated.
The purpose of the study is to evaluate the benefit of perioperative locoregional analgesia
by ropivacaine via a popliteal sciatic catheter on intravenous morphine consumption during
the 72 first postoperative hours following leg (below knee) amputation The study will be
randomized, double blinded, controlled clinical trial and 84 patients undergoing leg
amputation (below knee) will be included Patients will be divided into 2 groups: one group of
patients who will benefit perioperative locoregional analgesia by ropivacaine via a popliteal
sciatic catheter and morphine for analgesia and the other one who will benefit placebo
through the catheter and morphine.
The investigators will evaluate the efficacy of the continuous popliteal sciatic nerve block
in postoperative analgesia after leg amputation and prove the efficacy of a perioperative
analgesia by continuous popliteal sciatic nerve block to prevent phantom limb pain after leg
amputation in patients of ASA physical status 2 or 3.