Medium-term Incidence Study of Phantom Limb Syndrome in Trans Femoral and Trans Tibial Amputated Patients

The prevalence of phantom limb varies from 50-90% in amputated patients. When present, it is difficult to manage and has a significant impact on the patient's quality of life. The causes that determine the development and above all the persistence of this remote syndrome are not known, however some studies report the importance of psychological factors, also related to the time of use of the prosthesis.

After an amputation it is possible to have different pictures of residual pain that are classified as:

• Stump pain (residual limb pain -RLP): described as burning, shock, cut, hypersensitivity of the stump (post-surgical nociceptive, neurogenic, protesigenic, arthrogenic, ischemic, sympathetic, from adhesive scar tissue or hetero topical ossifications, has a incidence of 74% and may persist up to 14 years after amputation.
• Phantom limb pain (PLP) pain: described as a similar neuropathic (cutting, traction, shock pain) and as a similar nociceptive (deaf, cramp-like, compressive), is present in the first 6 months after amputation, but can last for years, and affects up to 85% of patients.
• Phantom limb sensations (phantom sensations - PSs): non-painful perceptions from the part of the body lost after deafferentation or amputation (kinetic, kinesthetic and exteroceptive), is common in the postoperative period, in one third of patients within 24 hours , in three quarters of patients within 4 days, and in 90% of patients, persist within 6 months of surgery.

At present, the scientific evidence shows that the infusion of local anesthetics with perioperative epidural and perineural catheters correlates with good pain control in the immediate post-operative period expressed in terms of reduced opiate demand by of the patient undergoing limb amputation. However, there are no studies on the medium to long-term incidence of phantom limb syndrome in patients who have been treated with multimodal analgesic protocols. Only the observational study performed by Borghi et al. showed that a 3% incidence of phantom limb syndrome in patients treated with prolonged infusion for an average of 30 days with a 0.5% ropivacaine perineural catheter was shown 12 months after limb amputation surgery. Based on this experience for years at the Rizzoli Orthopedic Institute, peridural and peripheral catheters are applied with a dedicated protocol. At present, however, there is no further assessment of the incidence of phantom limb in patients amputated to the IOR who have followed the protocols in use.

Aim The study aims to evaluate the incidence of phantom pain in the medium term, the sensation of phantom limb and the pain of the stump in amputated trans femoral and trans tibial patients operated on the IOR who followed the perioperative analgesic protocol with use of catheters peridural and peripheral nerves. The results of the study could provide indications about the need to modify the perioperative and rehabilitative analgesic therapy protocol for lower limb amputation surgery to favor a reduction in the intensity, prevalence and frequency of phantom limb syndrome with consequent improvement in the quality of life.