Unique Considerations for Complete Surgical Analgesia for Below-the-Knee Amputations

Recent cadaver studies have suggested that posterior femoral cutaneous nerve (PFCN) may contribute to the sensory innervation of the posterior lower leg. Whether this is clinically relevant may be revealed in patients who underwent below-the-knee amputation (BKA) with monitored anesthesia care (MAC) and peripheral nerve blocks. We performed femoral and sciatic nerve blocks for a 55-year-old male patient who underwent BKA and subsequent formalization surgeries as the main surgical analgesia while providing MAC in the operating room. In both cases, the patient could not tolerate surgical incisions in the posteromedial aspect of the lower leg, despite reporting no pain in other areas of the lower leg with surgical stimulation. There may exist a small population of patients in which PFCN makes significant contribution to the sensory innervation of the posterior lower leg. For these patients, the combination of femoral and sciatic nerve blocks may not be adequate in providing surgical analgesia for BKA and related procedures.