This case series describes a novel, regional anesthesia technique in three dogs of various breeds, aged 2.5, 8, and 10 years old, weighing 42.6, 32.6, and 13.4 kg, respectively, presenting for tibial plateau levelling osteotomy.
Physical examination was unremarkable aside from evidence of a ruptured cranial cruciate ligament. After anesthetic premedication and induction of general anesthesia, the affected limb was aseptically prepared. A combination of regional nerve blocks was performed, including the inFiLtrating Around Genicular Structures (FLAGS) block, saphenous block, and periarticular knee infiltration; together, termed the Flags Assisted WalKing block for Enhanced recovery after Surgery (FAWKES). A mixture of 0.5% ropivacaine (4 mg kg-1), dexmedetomidine (1.6 ug kg-1), dexamethasone sodium phosphate (0.004 mg kg-1), and epinephrine (4 ug kg-1) was used for the FLAGS (0.2 mL kg-1), saphenous (0.1 mL kg-1), and periarticular knee infiltration (0.125 mL kg-1 per site; four sites). There were no increases in heart rate, respiratory rate, or mean arterial blood pressure greater than 20% from surgical start time to end time, aside from expected elevations following administration of anticholinergics or vasopressors.
All dogs retained motor function postoperatively. Two of the three dogs ambulated on the operated limb within one hour of recovery. The third was nonweight-bearing but able to flex the stifle and elevate the limb. One dog was given a single postoperative dose of intravenous methadone (0.2 mg kg-1) 12 hours after surgery, whereas the remaining dogs required no rescue analgesia. All dogs ate within 12 hours of surgery and were discharged without complications.
These findings suggest that the described multimodal analgesic plan, including the FAWKES block, provided adequate intraoperative analgesia while preserving motor function postoperatively. Controlled studies are required to evaluate the efficacy and safety of the FAWKES block, along with more detailed anatomical investigations of the canine stifle joint.
