Rheumatology:OSTEOARTHRITIS

RHEUMATOID ARTHRITIS

Dr. Meg-angela Christi Amores

OSTEOARTHRITIS

• Most common type of arthritis• leading cause of disability in the elderly• Mostly affects >65 yrs old

Osteoarthritis

• Commonly affected joints:• cervical and lumbosacral

spine, hip, knee, and first metatarsal phalangeal joint (MTP)

• distal and proximal interphalangeal joints and the base of the thumb

• Usually spared are the wrist, elbow, and ankle

Osteoarthritis

• Structural changes:• nearly universal by the elderly years• cartilage loss (seen as joint space loss on x-rays) and

osteophytes

Severe osteoarthritis in...

• distal interphalangeal joints (Heberden's nodes)

• proximal interphalangeal joints (Bouchard's nodes)

Osteoarthritis

• OA is joint failure– a disease in which all structures of the joint have

undergone pathologic change– hyaline articular cartilage loss– increasing thickness and sclerosis of the

subchondral bony plate, by outgrowth of osteophytes at the joint margin, by stretching of the articular capsule, by mild synovitis

Joint protective mechanism

• Joint protectors include: joint capsule and ligaments*, muscle, sensory afferents~, and underlying bone

• *Fixing the range of joint motion• ~providing feedback , anticipating joint loading

• Synovial fluid: major protector against friction-induced cartilage wear

• depends on the molecule lubricin• concentration diminishes after joint injury

Osteoarthritis

• Major risk factors:– Joint vulnerability and joint loading – vulnerable joint whose protectors are

dysfunctional can develop OA with minimal levels of loading

– in a young joint with competent protectors, a major acute injury or long-term overloading is necessary to precipitate disease

Osteoarthritis

• Other risk factors:– Age (incidence of disease rising dramatically with age)

– hormone loss with menopause – Highly heritable– Hip OA is rare in China, Knee OA is frequent– Major injuries to a joint : e.g. Fracture– Obesity– Repeated use of joint : e.g sports, farming, etc– Malalignment: e.g. varus, valgus

• varus, in which the stress is placed across the medial compartment of the knee joint, and valgus, which places excess stress across the lateral compartment of the knee

Clinical features: OA

• Activity-related joint pain• during or just after joint use

• knee or hip pain with going up or down stairs• pain in weight-bearing joints when walking• for hand OA, pain after cooking

• Brief morning stiffness <30 mins

Treatment• mild and intermittent symptoms may need

only reassurance or nonpharmacologic treatments:

• altering loading across the painful joint • avoid activities that precipitate pain• Exercise• Correction of malalignment

• with ongoing, disabling pain are likely to need both nonpharmaco- and pharmacotherapy

• Acetaminophen, Nonsteroidal Anti-Inflammatory Drugs (NSAIDs), and COX-2 Inhibitors

Rheumatoid arthritis

Rheumatoid Arthritis

• chronic multisystem disease of unknown cause

• persistent inflammatory synovitis, usually involving peripheral joints in a symmetric distribution

• Hallmark: potential of the synovial inflammation to cause cartilage damage and bone erosions and subsequent changes in joint integrity

Rheumatoid Arthritis

• Epidemiology– prevalence of RA is ~0.8% of the population – Women > men ( 3:1 )– seen throughout the world and affects all races– onset is most frequent during the fourth and fifth

decades of life– genetic predisposition

Rheumatoid Arthritis

• Unknown cause• might be a manifestation of the response to

an infectious agent in a genetically susceptible host

• Mycoplasma, Epstein-Barr virus (EBV), cytomegalovirus, parvovirus, and rubella virus• but convincing evidence that these or other infectious

agents cause RA has not emerged

Rheumatoid Arthritis

• propagation of RA is an immunologically mediated event

• earliest event appears to be a nonspecific inflammatory response

• cascade of cytokines produced in the synovium activates a variety of cells in the synovium, bone, and cartilage to produce effector molecules that can cause tissue damage

Rheumatoid Arthritis

Clinical features

• chronic polyarthritis• begins insidiously with fatigue, anorexia,

generalized weakness, and vague musculoskeletal symptoms

• hands, wrists, knees, and feet, become affected in a symmetric fashion

• by constitutional symptoms, including fever, lymphadenopathy, and splenomegaly (10%)

Clinical features

• Prolonged morning stiffness (>1 hr)• swelling, tenderness, and limitation of motion• distal interphalangeal joints are rarely involved• Synovitis of the wrist joints is a nearly uniform

feature of RA

Rhuematoid Arthritis- hand

• “Z” deformity• radial deviation at the wrist with ulnar deviation of the

digits, often with palmar subluxation of the proximal phalanges

• swan-neck deformity• hyperextension of the proximal interphalangeal joints,

with compensatory flexion of the distal interphalangeal joints

• boutonnière deformity• flexion contracture of the proximal interphalangeal joints

and extension of the distal interphalangeal joints

Extraarticular manifestations

• a systemic disease with a variety of extraarticular manifestations– Rheumatoid nodules – Clinical weakness and atrophy of skeletal muscle – Rheumatoid vasculitis – Pleuropulmonary manifestations– Felty's syndrome – Osteoporosis

Laboratory tests

• RF (rheumatoid factor)• 2/3 of patients• not specific for RA, present in 5% of healthy

• Anti-CCP• Normochromic, normocytic anemia • ESR increased• Synovial fluid analysis

• fluid is usually turbid, with reduced viscosity, increased protein content, and a slightly decreased or normal glucose concentration

Treatment

• Goals:– 1) relief of pain, (2) reduction of inflammation, (3)

protection of articular structures, (4) maintenance of function, and (5) control of systemic involvement

• Pain meds:– First line: NSAIDS– 2nd line: steroids (glucocorticoids)– 3rd line: DMARDS (methotrexate, gold)

OA vs RAOSTEOARTHRITIS RHEUMATOID ARTHRITIS

Age frequent

Hand involvement

Wrist involvement

Onset of pain

Morning stiffness

Special features: