Rheumatoid Arthritis

Pathophysiology

Inflammatory reaction Swelling & hypertrophy of synovial membrane Formation of lymphoid nodules (granulomas) in lungs, pericardium and sclera Destruction of joint cartilage, capsule & ligaments Synovial sac protrusion & rupture (eg. Baker's cyst) Secondary muscle atrophy, due to disyse

Clinical Features

Sites   Hands - intercarpal joints, metacarpophalangeal joints, proximal interphalangeal joints Feet - Tarsal and lateral metatarsophalangeal joints Knees Cervical spine Joints   Morning stiffness Rest pain Symmetrical polyarthritis - affects multiple joints Joint Swelling around the joint - (in hands, valley filling) Cyclic pattern - flare ups followed by remissions Restricted movement Joint crepitus Joint instability Deformity   Boutonniere Swan neck Z Extra articular   Rheumatoid nodules - forearm & elbow Granulomas occur in sclera of eye, myocardium, pericardium, pleura Inflammation - scleritis, pericarditis, pleuritis, arteritis, vasculitis Entrapment neuropathy - Carpal tunnel syndrome, due to inflammed synovium Peripheral neuropathy - glove & stocking sensory loss, dur to vasculitis

Investigations

Diagnostic   Bloods   FBE   Iron deficiency anaemia - GI blood loss due to treatment with NSAIDs Normochromic, normocytic anaemia of Chronic disease ESR   Elevated RF   Positive in 70% of patients ANA   May be positive Radiology   X-Ray of affected joints     Periarticular osteopaenia Joint space narrowing Errosions Subluxation Joint ankylosis Periarticular soft tissue swelling

Treatment

Conservative   Education Resting affected joints during active inflammation Physiotherapy - Heat treatment & increasing movement range NSAIDs - intermittently because it may depress joint healing Disease modifying antirheumatic drugs   Sulfasalazine - response seen in 3 - 6 months Methotrexate - response in 4 - 6 weeks Intra-articular hydrocortisone injections - for immediate relief of inflammatory pain Prednisolone - severe execcerbations, unresponsive to other treatment. Analgesics Operative   Only considered if conservative treatment is inadequate Debridement   Removing osteophytes to increase movement range Only performed on small joints with severe movement restriction (hand), not on large weight bearing joints (hip & knee) Arthrodesis   Fusion of joints - converting a stiff, painful joint in bad position to a stiff, painless joint in good position Useful for smal joints in the hand, where loss of movement in one joint can be disguised by the joints around it Not performed in rheumatoid arthritis, or if joints above and below are impaired Realignment osteotomy   Cutting of bone to correct alignment Slows deterioration Performed in young, active patients Long rehabilitation required Arthroplasty   Total joint replacement with a prosthesis Performed in older, inactive patients