Arthroplasty, Replacement, Knee
Conditions
Keywords
Pain Management; Analgesics, Opioid; Cannabis
Brief summary
Total knee replacement is a major and painful orthopaedic (joint and bone) surgery where the knee joint is replaced with an artificial joint. It is an effective and successful procedure to treat severe knee arthritis and reduce pain, but many patients report intense pain after the surgery. Postoperative pain control is predominated by opioids (morphine-based drugs). While opioids are effective to manage the pain, they can have acute and chronic complications, including confusion, nausea, vomiting, constipation and high risk of addiction. Medical cannabis is an effective and safe alternative for pain treatment. Recent studies showed that patients have reported a reduction in opioid usage when taking cannabis as a substitute for pain relief. This study aims to investigate whether adding medical cannabis (cannabidiol - CBD) treatment will decrease the amount of opiates needed in the first 2 weeks after knee replacement compared to a group given placebo.
Detailed description
COPE (Cannabinoids to Obviate Pain Experiment after knee replacement) will be a single-centre, prospective, randomized, placebo-controlled, superiority trial, with two parallel groups designed to investigate the effect of cannabis as postoperative pain treatment compared to placebo on total opioid consumption after total knee replacement. Eligible patients are: men and non-pregnant women aged ≥18 years scheduled to undergo primary total knee replacement. and with no opioid usage within the last 3 months or history of narcotic abuse. Patients will be recruited at the department of orthopaedic surgery at St Michael's Hospital (Toronto - Canada), and informed consent will be obtained from those eligible. Central computer-generated randomization will be used to randomly assign participants to cannabis or placebo groups (1:1 ratio). Only the study pharmacist will know allocated treatments.
Interventions
DRUGCannabinol
Postoperative pain treatment
DRUGPlacebo oral capsule
Placebo comparator
Sponsors
Unity Health Toronto
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Intervention model description
Parallel Assignment
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 18 years of age and older * Men and women * Patients with radiographic confirmation and clinical correlation for severe osteoarthritis diagnosis with an indication for total knee replacement * Patients undergoing primary unilateral total knee replacement * Patient is able to provide informed consent to participation in the study
Exclusion criteria
* Pregnancy * Breastfeeding * Current opioid use * Cognitive impairment or mental illness (e.g., dementia, Alzheimer disease and psychoses), which will prevent patients from reliably providing primary outcome data * Unable to swallow an oral tablet (medication) * History of opiate, narcotic and alcohol abuse * Revision total knee replacement surgery * High risk of falls as determined by the treating physician * Patients refusing participation * Pre-existing/ regular cannabis use
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Opioid consumption | 2 weeks after total knee replacement | Assess cumulative opioid consumption (morphine equivalent dose) by means of drug reconciliation (medication diaries and pill counts) i.e. patients will self report how many opioid pills they took each day, by means of the medication diaries and at 4 weeks follow up will bring the pills back to clinic appointment. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Oxford knee score | Questionnaire will be completed by patients at 6 weeks after knee replacement | A short questionnaire consists of 12 questions ranging from 0 to 48 points, designed to assess function and pain after knee replacement surgery. Higher values represent a better outcome. Scores between 40-48 indicate satisfactory joint function |
| Health status and quality of life | Questionnaire will be completed by patients at 6 weeks after knee replacement | EQ-5D is a questionnaire where patients self-rate their level of severity of health status and health-related quality of life. Consists of 5 dimensions (mobility, self care, usual activities, pain/discomfort, anxiety/depression) and each one of them has 5 levels (no problems, slight problems, moderate problems, severe problems, and extreme problems) where patients will indicate how they feel regarding their health status and quality of life. |
| Visual Analog Pain Scale | Pain scale will be assessed at 24 hours, 2, 6 and 12 weeks after knee replacement | Assess pain from a visual scale that ranges from 0 to 10. Straight line with the endpoints defining extreme limits such as 'no pain at all' (zero) and 'pain as bad as it could be' (ten) |
| Self-reported opioid use and urinalysis | The test will be completed at 12 weeks after knee replacement | Patients will self report whether they are still using opioids (yes or no) and they will undergo a urinalysis (urine test). Patients will pee in a designed cup and a trained assessed will test the urine (with chemical strip) to detect the presence of one or more opioids in urine. |
| Narcotic monitoring prescription | Will be assessed at 12 months after knee replacement | Using data from the Narcotics Monitoring System from ICES (Institute for Clinical Evaluative Sciences) which already captures all opioid prescriptions dispensed in retail pharmacies across Ontario, the investigators will assess if participants have had any filled prescription after knee replacement and record the number of prescriptions filled. |
| Quality of recovery - 15 (QoR-15) | Questionnaire will be completed by patients at 12 weeks after knee replacement | Quality of recovery scores are patient-reported outcome measures evaluating recovery after surgery regarding the last 24h. It is a short-form score with 15 questions that assess the 5 dimensions (pain, physical comfort, physical independence, physiological support and emotional state) and has 2 parts (A and B). Part A scores from 0 \[poor\] to 10 \[excellent\] - as higher is the score as better is the recovery. Part B scores from 10 \[excellent\] to 0 \[poor\] - as higher is the score as better is the recovery. |
Countries
Canada
Contacts
Primary ContactLuana Melo, PhD
Outcome results
None listed