Patient case (clinical description): A 66-year-old woman comes to the office due to joint pain in the hands and periodic morning stiffness that lasts less than 15 minutes.  The pain is moderately severe and worsens with daily activity. The patient used Tylenol with minimal relief.  Past medical history is notable for hypertension and hypercholesteremia.  Physical examination shows firm nodules over the distal interphalangeal joints, bilaterally. The patient has pain in her knees as well. The knees are stiff in the morning for less than 30 minutes and become worse with climbing stairs. She has some sensation of bone friction during activity. X-ray shows narrowing of the joint space, subchondral bone sclerosis and osteophyte formation along the joints.

Patient's own account: I'm a 66-year-old woman and I went to my doctor's office because of a bloody joint pain in my hands that has been lasting for a while. The pain comes and go in the morning usually. I feel like a stiffness that last less than 15 minutes. The pain is moderately severe but it gets worse when I'm using my hands. I used Tylenol which helped a little. Apart from that, I suffer from hypertension and high cholesterol. The doctor made me notice that I have bumps around both of my hand joints. I also suffer from my knees and they are also stiff in the morning for around 30 min. It's even worse when I climb up the stairs! I also feel like my bones are rubbing against each other when I'm moving. The X-ray showed that I have narrow joint space, I have sclerosis, and abnormal growths of bone along my joints.

Clinical trial: A Four-Arm Study Comparing the Analgesic Efficacy and Safety of Tramadol Once a Day 100, 200 and 300 mg Versus Placebo for the Treatment of Pain Due to Osteoarthritis of the Knee (With 7-Day Follow-up)

Eligibility criteria:
Inclusion Criteria:

          1. Males or Females between the ages of 40-75 with a diagnosis of moderate to severe
             osteoarthritis of the knee, consistent with the ACR Clinical Classification Criteria
             for Arthritis of the Knee:

               -  Current knee pain.

               -  Less than 30 minutes of morning stiffness with or without crepitus on active
                  motion.

               -  Confirmation either by arthroscopy or radiologist's report (X-rays showing
                  osteophytes, joint space narrowing or subchondral bone sclerosis {eburnation})
                  within five years prior to entry into the study.

          2. CRP < 8 ug/mL (if available at local lab) or ESR < 40 mm/hr.

          3. Total WOMAC (Western Ontario and McMaster University Osteoarthritis Index) Pain
             Subscale Score of > 150 mm at Baseline corresponding with moderate to severe
             Osteoarthritis.

          4. Oral and written language comprehension at a level sufficient to comply with the
             protocol and complete study-related materials.

          5. REB approval of the written Informed Consent Form in Spanish or English which was
             signed and dated by the patient and Investigator, prior to study participation.

        Exclusion Criteria:

          1. Known rheumatoid arthritis or any other rheumatoid disease.

          2. Secondary arthritis i.e. any of the following: septic arthritis; inflammatory joint
             disease; gout; pseudogout; Paget's disease; joint fracture; acromegaly; fibromyalgia;
             Wilson's disease; ochronosis; haemochromatosis; osteochondromatosis; or collagen gene
             mutations.

          3. Evidence of effusion greater than 15 cc upon physical examination of the joint at
             Baseline (Visit 1).

          4. BMI greater than or equal to 38.

          5. Major illness, requiring hospitalization during the 3 months before commencement of
             the screening period.

          6. Unwillingness to stop taking pain medication (for arthritis or other types of pain) or
             was unwilling to stop taking other medications for the treatment of OA.

          7. Previous failure or discontinuation (due to adverse events) of tramadol HCl therapy.

          8. Treatment within the last 3 weeks with any of the following medications: monoamine
             oxidase inhibitors; tricyclic antidepressants and other tricyclic compounds (e.g.
             cyclobenzaprine, promethazine); neuroleptics; selective serotonin reuptake inhibitors;
             or any other drug that reduces seizure threshold.

          9. Treatment with another investigational agent within the last 30 days.

         10. A history of seizure disorder other than Infantile Febrile Seizures.

         11. Previous or current opioid dependency.

         12. Bowel disease causing malabsorption.

         13. Pregnancy or lactating or childbearing potential and unwilling to utilize a medically
             approved method of contraception during participation in this clinical trial.

         14. Significant liver disease, defined as active hepatitis or elevated liver enzymes >3
             times the upper boundary of the normal range.

         15. Significant renal disease, defined as creatinine clearance <30 mL/min as estimated by
             the method of Levey et al., 1999.

         16. Current substance abuse or dependence, other than nicotine.

         17. Allergy or adverse reaction to tramadol or any structurally similar drugs e.g.
             opiates.

         18. Any other condition that, in the opinion of the Investigators, would have adversely
             affected the patient's ability to complete the study or its measures.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 40 Years old.
Subject must be at most 75 Years

Eligibility (NLI label): Entailment