FAB Block vs. Placebo for Hip Arthroplasty Patients

Hip arthroplasty procedure is frequently associated with severe post-operative pain despite the practice of injecting the hip joint with local anesthetics at the end of the procedure and the use of intraoperative opioids. These patients usually receive a spinal anesthetic as well. The ideal analgesic technique that provides adequate pain relief following this procedure has not been established yet. The femoral articular branch block (FAB) has recently been proposed to collectively block the terminal femoral and accessory obturator nerve branches to the hip joint with a single injection, theoretically blocking most of the innervation relevant to hip arthroscopy while sparing the main femoral nerve branches to the quadriceps muscle. The investigators aim to demonstrate the analgesic benefits of FAB.