2026 FSA Podium and Poster Abstracts

Introduction: Below the knee amputation (BKA) is a procedure utilized in treatment and resection of lower extremity malignancy, including osteosarcoma. Regional anesthesia techniques, including single-shot and continuous catheter blocks, are frequently utilized, providing targeted pain management. While single-shot blocks traditionally offer shorter-duration analgesia of 8-14 hours¹, adjunctive agents may be utilized to prolong the effect^1,2. We describe a case of BKA for treatment of osteosarcoma utilizing adductor canal and popliteal sciatic nerve blocks, utilizing dexamethasone and dexmedetomidine to prolong anesthetic effect, with zero intraoperative and post-operative opioid use.  

Methods: An 18-year-old, 60kg male with osteosarcoma of the left lower leg with intra-articular extension to the ankle and previous neoadjuvant chemotherapy presented for BKA. Ketamine and gabapentin were utilized to reduce the risk of phantom limb pain. 

Preoperatively, popliteal sciatic and adductor canal blocks were administered with fentanyl (100mcg) and midazolam (2mg) for sedation. Both blocks were ultrasound-guided; the adductor canal block was administered with 0.5% ropivacaine (15mL), PF dexamethasone (4mg), dexmedetomidine (10mcg), and 1:400K epinephrine. The popliteal sciatic block was administered with 0.5% ropivacaine (25mL), PF dexamethasone (6mg), dexmedetomidine (20mcg), and 1:400K epinephrine. Aprepitant (40mg), acetaminophen (1g), and a scopolamine patch were given. Additional midazolam (2mg) was given for anxiolysis prior to OR transfer. 

General endotracheal anesthesia was utilized, with propofol and ketamine (20mg) for induction and rocuronium paralysis. Maintenance included sevoflurane, dexmedetomidine (0.4mcg/kg/hr), and ketamine (0.1mg/kg/hr). The patient exhibited no response to surgical incision or amputation. Intraoperatively, phenylephrine boluses were used to maintain blood pressure. Intraoperative antiemetics included ondansetron (4mg) and dexamethasone (4mg). Ketorolac (30mg) was given at closing. Estimated blood loss was 110mL, and 1600mL of crystalloid was given. Prochlorperazine (2.5mg) was given in PACU for nausea. Gabapentin (300mg TID), and acetaminophen (1g Q6H) were given postoperatively. No opioid was used intraoperatively, in PACU, or on the floor prior to discharge.   

Results: The adductor canal nerve block provided anesthesia to the medial leg and foot in tandem with the popliteal sciatic nerve block, which provided anesthesia to the sensory distribution of the lower leg not supplied by the saphenous nerve, as well as the hamstring muscles and posterior aspect of the knee. The single-shot nerve blocks utilized provided sufficient analgesia through the entirety of the patient’s hospital course, without the use of a continuous catheter or repeat blocks. The patient was discharged on post-operative day two, with minimal pain 3/10 and without the patient requesting his PRN Oxycodone or Dilaudid.  

Conclusions: The use of regional nerve blocks with a multimodal anesthetic approach provided adequate intraoperative anesthesia and post-operative analgesia while permitting early mobilization and zero intraoperative or post-operative opioid usage prior to discharge. Regional nerve blocks provided additional analgesia for a potentially painful amputation in a young patient, who is at higher risk of poor pain tolerance compared to older patients ^3,4. Single-shot adductor canal and popliteal sciatic nerve blocks extended with dexmedetomidine and dexamethasone provided regional anesthetic coverage while avoiding the use of a peripheral nerve block catheter and its associated risks, costs and follow-up logistics.