Effects of Dietary Supplement on Osteoarthritis

This study evaluates the effects arginine on osteoarthritis (OA) in adults. Participants will be randomly divided into two groups, taking arginine and nothing, respectively. Outcomes will be evaluated by lab test results on OA joint cartilage and self-administered questionnaires. The hypothesis is that arginine can slow down or reverse OA.

1. Patients that meet the inclusion criteria will be approached by a member from their care team, details of this study will be explained. Verbal consent to screening will be obtained during this phone interview and recorded in the clinical trial database; patients will be screened for their eligibility, and a clinical visit will be arranged for eligible patients.
2. Consent form and questionnaires that are commonly used to collect general health information and assess OA patients' mental and physical functions (General Questionnaire, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and 36-Item Short Form Health Survey (SF-36)) will be mailed to eligible patients. Patients will read consent form and fill up questionnaires.
3. Eligible patients will be reached by phone by the research assistant at a later date to obtain their verbal consent to further contact regarding participating in the study, and consent status will be recorded in the clinical trial database.
4. Initial clinical visit:

   1. All questions and concerns will be answered by researchers, consent form will be signed by participants, research assistant, and one of the investigators, and participants will be given a copy as record.
   2. Questionnaires (baseline) will be collected.
   3. 6.5 ml of blood sample (baseline) will be collected by a qualified research nurse.
   4. Participants will be randomly divided into 2 groups, each group will receive arginine and instruction or nothing, and will take arginine or nothing for 6 months:

      * Group I (n=50): 1.5 g of L-arginine daily.
      * Group II (n=50): No supplement.
5. Pre-admission clinical vist:

   * WOMAC and SF-36 questionnaires (at 6 months of the trial) will be administered.
   * 6.5 ml of blood sample (at 6 months of the trial) will be collected.
6. During total joint replacement surgery, small pieces of replaced joint cartilage tissue, which are normally thrown away, will be collected.
7. At 6 and 12 months after the surgery, participants will be reached via phone by the research assistant to complete WOMAC and SF-36 questionnaires. A blood requisition form will be mailed to participants after the last phone interview for their next scheduled routine fasting blood work; 4 ml of blood sample will be collected for the study and sent to the clinical trail lab by the blood collection centre.
8. Lab testing will be conducted; all outcome data will be obtained and analyzed.

Eligibility Criteria:
Inclusion Criteria:

* Undergoing total knee replacement surgery in 6 months due to primary knee OA
* Must be ambulatory
* Must live in 50 kilometers perimeter of St. John's, capital city of Newfoundland and Labrador, Canada

Exclusion Criteria:

* Clinical diagnosis of secondary OA or inflammatory arthritis
* Cod liver oil supplementation within 6 months
* Supplementation containing arginine within 6 months
* Osteoporotic fracture, previous knee surgery or arthroscopy within 6 months
* Use of bisphosphonates within 2 years
* Use of Intra-articular viscosupplementation or platelet rich plasma at any point