Hip arthroplasty surgery can be associated with significant pain. A regional anesthesia technique, the femoral articular branch block (FAB), has recently been proposed to collectively block 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 muscles. The investigators aim to demonstrate the analgesic benefits of FAB. The investigators hypothesize that FAB will reduce opioid consumption and improve postoperative quality of recovery in patients having hip arthroplasty. This is a randomized, controlled, double-blind study and half the patients will be randomized to receive the femoral articular branch block and the other half of patients will be randomized to receive a placebo block. A comparison of pain will be made between both groups.

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.

Inclusion Criteria:

• ASA I-III patients
• Ages 18-60yrs
• BMI ≤ 35 kg/m2

Exclusion Criteria:

• Preexisting neurological deficits or peripheral neuropathy in the distribution of femoral, obturator, or lateral cutaneous nerves
• Local infection
• Contra-indication to regional anesthesia e.g. bleeding diathesis, coagulopathy
• Chronic pain disorders
• History of use of over 30mg oxycodone or equivalent per day
• Contraindication to a component of multi-modal analgesia
• Allergy to local anesthetics
• History of significant psychiatric conditions that may affect patient assessment
• Pregnancy
• Inability to provide informed consent
• Patient refusal of FAB
• Revision arthroscopy surgeries

The anesthesiologist performing the nerve block will be aware of group allocation; but a separate anesthesiologist providing intra-operative care will remain blinded. The patient and the research staff collecting outcome data will remain blinded until all data are collected.