Rheumatoid Arthritis Treatment and Biopsy Study Assessing Certolizumab Pegol (Cimzia)

Inclusion Criteria: * Signed and dated informed consent document * Subjects must be at least 18 years of age or older * Subject must be willing and able to comply with scheduled visits, arthroscopy, laboratory tests, and other procedures * Diagnosis of RA based on American College of Rheumatology (ACR) 1987 Revised Criteria * Active disease at screening visit * Methotrexate taken continuously for at least 12 weeks at a stable dosage * Sexually active women of child-bearing potential and men whose partners are women of child-bearing potential are required to use adequate contraceptive methods during participation on this trial * Treatment with non-steroidal anti-inflammatory drugs (NSAIDS)and oral corticosteroids (less than or equal to 10 mg/day prednisone or equivalent)is accepted Exclusion Criteria: * Diagnosis of any other inflammatory arthritis * History of infected joint prosthesis that is still in situ * History of allergy to local anesthetic agents * Pregnant or lactating women * Current or recent history of uncontrolled clinically significant conditions(e.g..,kidney disease, liver disease, class III or IV congestive heart failure, according to the New York Heart Association) * History or suspected demyelinating disease of the central nervous system, e.g. multiple sclerosis or optic neuritis * Current participation in clinical trial