Incidence of Phantom Limb Pain and Method of Anesthesia After Lower Extremity Amputation

Phantom limb pain (pain originating from where an amputated limb once was) is a common occurrence after lower extremity amputations, with some sources noting incidence to be as high as 60-80% six months after surgery. This pain can eventually subside, however, cases have been reported of incidence 10 years after surgery. This pain is not only physically detrimental, but can also be psychologically detrimental after a difficult to accept change in the body. Prior studies have been performed using regional anesthetic techniques (including spinals and epidurals) and different medications to attempt to reduce the incidence of phantom limb pain, however, the data have been mostly inconclusive. Of interest, prior studies have not addressed peripheral nerve blocks, a method of anesthesia/analgesia more commonly employed for amputations recently. The purpose of our retrospective study is to look at the incidence of phantom limb pain at our institution over a two year period to determine if peripheral nerve blocks result in a significantly reduced incidence compared to other techniques (spinal, epidural, general anesthesia only). In addition, there is little data on relation of reason for amputation and presence of preoperative neuropathy and incidence of phantom pain. As secondary endpoints, the investigators wish to investigate if certain reasons for amputation (trauma, peripheral vascular disease, diabetes, and others) and/or neuropathy lead to a higher incidence of phantom limb pain. The results of this study could impact future management of patients who are to receive amputations and may lead to further prospective studies on the topics involved.