Perioperative Vitamin C to Reduce Persistent Pain After Total Knee Arthroplasty

PeRiOperative VItamin C to Reduce perSistent paIn After tOtal kNee Arthroplasty (PROVISION): a Pilot Multicentre Randomized Controlled Trial

Phase II Multicentre, pilot, parallel-group, blinded, 1:1 randomized controlled trial to determine the feasibility of conducting a larger definitive trail of using vitamin C to reduce persistent pain in patients undergoing total knee arthroplasty surgery.

PROVISION is a multicentre, pilot, parallel-group, blinded, randomized controlled trial of 400 patients undergoing total knee arthroplasty surgery. Consented eligible patients will be randomized to receive vitamin C: 2000 mg taken orally within 4 hours of the start of surgery, followed by 500 mg of vitamin C taken twice daily from post-operative day 1 to day 56 (8 weeks). Patient in the control group will receive placebo lactose monohydrate capsules. Study medications will be prepared to look similar and labelled as per regulatory requirements. Patients will follow up on post-operative days 1-3, weeks 2,4,6, and 8 post-operatively, and at 3- and 12-months post-operatively to report on pain, opioid and analgesic consumption, medication adherence, adverse events, functional, mood, and quality of life outcomes.

Inclusion Criteria:

• Patients >18 years old
• Undergoing a unilateral or bilateral primary total knee arthroplasty for advanced osteoarthritis of the knee

Exclusion Criteria:

• TKA for infection (septic joint), fracture, ankylosing spondylitis, lupus, or psoriatic arthritis
• History of kidney stones, acute or chronic renal failure, hemochromatosis, or glucose-6-phosphate deficiency
• Unlikely to comply with follow-up (e.g., no fixed address, plans to move out of town)
• Language difficulties that would impede valid completion of questionnaires
• Planned staged bilateral TKA
• Treating surgeon deems patient inappropriate for inclusion in trial
• Any allergy or sensitivity to milk
• Pregnant or planning to become pregnant during the study