Adductor canal blocks (ACB) have been recommended in total knee arthroplasty (TKA) to provide better control of post-operative pain, facilitate early ambulation, and reduce length of stay in the hospital. ACB is typically done before surgery by an anesthesiologist, which may increase time per case, cost, and requires the specialized skills of an anesthesiologist trained in regional anesthesia. Recent studies have suggested that surgeons can safely and reliably administer the adductor canal blocks (sACB) during surgery. However, there is currently very limited data on the clinical efficacy of such sACBs, and no studies assessing this technique in the context TKA that are discharged the same day. As such, this randomized control trial (RCT) is being done to compare sACBs to conventional anesthesiologist-performed adductor canal blocks (aACB).

Inclusion Criteria:

1. Male and female patients aged 18 years or older
2. Primary TKA booked as SDD
3. Diagnosis of osteoarthritis

Exclusion Criteria:

1. Inability or refusal to sign informed consent form
2. Non-English or French speaking, and no licensed translator, family member or substitute decision maker available.
3. Non-osteoarthritis primary diagnosis
4. Allergy to analgesic medications
5. Contraindication to spinal and/or regional anaesthesia
6. Any use of opioid pain medication within four weeks of the index procedure(13)
7. Pain catastrophizing scale score ≥16 (8, 9, 14)
8. History of cirrhosis
9. History renal insufficiency
10. History or sensory and/or motor neuropathy to the ipsilateral limb
11. Simultaneous, bilateral TKA
12. Non-TKA prosthesis
13. Scheduled for non-SDD TKA.
14. Preoperative varus/valgus of >10 degrees.
15. Planned General Anaesthetic
16. Use of Intrathecal Morphine