Osteoarthritis Flashcards
What is OA?
- ** slowly progressive non-inflammatory disorder of the diarthrodial (synovial) joints.**
- Not a normal consequence of aging but growing older continues to be consistently identified as one risk factor for disease development.
- Cartilage destruction **can actually begin between ages 20 and 30, but the majority of adults are affected by age 40. **
Pathological Changes
Breakdown of joint cartilage and narrowing of the joint space. Cartilage loss can cause bone to rub on bone in a joint
Cause
Idiopathic (primary) - spontaneous origin and without apparent cause.
Secondary - caused by a known event or condition that directly damages cartilage or causes joint instability.
- Trauma i.e. dislocations, fractures
- Mechanical stress - overuse of joints
- Inflammation
- Joint instability
- Obesity
- Neurologic disorders
- Skeletal deformities
- Side effects of medications
- Genetic predisposition
Behaviors
Joints
- Range from mild discomfort to significant disability.
- In early stages - joint pain increases with use, relieved with rest.
- Early morning stiffness usually resolved within 30 minutes after movement.
- In advanced stage - the client may complain of pain with rest or experience sleep disruptions caused by increasing joint discomfort.
- Pain may become worse as barometric pressures fall before inclement weather. Clients may experience more arthritis pain on cold, rainy days and less pain on warm, dry days.
- Overactivity can cause a mild joint effusion that temporarily increases stiffness.
- Crepitation, a grating sensation caused by loose particles of cartilage in the joint cavity, can also contribute to stiffness.
_OA usually affects joints asymmetrically
Joints most frequently involved in OA:_
- Distal interphalangeal (DIP)
- Proximal interphalangeal (PIP)
- Carpometacarpal joint of thumb
- Weight being joints (hips, knees)
- Metatarsophalangeal (MTP) joint of the foot
- Cervical and lower lumbar vertebrae
Deformity
- Specific to the involved joint
- Heberden’s nodes - DIP joints
- Bouchard’s nodes - PIP joints
- Both are often red, edematous, and tender
- Do not usually cause significant loss of function but the client may be distressed by the visible disfigurement
Diagnostic Studies
- Bone scan, Computed tomography (CT) scan, Magnetic resonance imaging (MRI), X-ray
- Radiologic changes do not always correlate with the degree of pain experienced by the client.
- Synovial fluid analysis allows differentiation between OA and other forms of inflammatory arthritis
- In the presence of OA, the fluid remains clear yellow with little or no sign of inflammation
- The erythrocyte sedimentation rate (ESR) or “sed rate” is normal except in instances of acute synovitis, when minimal elevations may be noted
- _WBC count of synovial fluid is less _
Acetaminophen
Mild-to-moderate joint pain
· Analgesic, not an anti-inflammatory
· Inhibits synthesis of prostaglandins in the CNS, has only minimal effects at the peripheral sites
· Not to exceed 4 g/24 hrs
· Adverse effect is liver toxicity, esp. in chronic alcoholics
Topical agent (Capsaicin cream)
- May be beneficial, either alone, or in conjunction with acetaminophen.
- Blocks pain by locally interfering with substance P, which is responsible for the transmission of pain impulses.
- Made from chili peppers - warn patients to expect a strong initial sensation of burning, to wash their hands after application, and to keep their hands away from their eyes.
NSAIDS
- For the client who fails to obtain adequate pain management with acetaminophen or for the client with moderate to severe joint pain, NSAIDs may provide greater relief - Advil, Motrin, Naproxen
- Analgesic and anti-inflammatory
- Traditional NSAIDs act by inhibiting Cox-1 and Cox-2
- Risk for GI irritation, decrease platelet aggregation - prolongs bleeding time.
- Take with food or milk to reduce gastric upset. For more severe GI upset, Misoprostol or a proton pump inhibitor i.e. Pantoloc.
- When given in equivalent anti-inflammatory dosages, all NSAIDs are considered comparable in efficacy but vary widely in cost.
- Individual responses to the NSAIDs are also variable.
- Aspirin should not be used in combination with NSAIDs because both inhibit platelet function and prolong bleeding time.
Selective NSAIDS
· Inhibits Cox-2 enzyme (responsible for inflammation)
· Little effect on Cox-1 (important for stomach protection and blood clotting)
· Similar anti-inflammatory to traditional NSAID action but lower risk for GI side effects
· Cardiovascular risk (Vioxx) - withdrawn from the market
Intraarticular Injections
Cortisone (steroid) - locally reduces pain and swelling - acts by inhibiting synthesis and/or release mediators of inflammation
Hyaluronic acid (e.g. Synvisc) - exact mechanism of action is unclear, although increasing the viscoelasticity of the synovial fluid appears to play a role
- May be appropriate for the client with local inflammation and effusion.
- May temporarily relieve the pain and inflammation associated with flare-ups.
Surgery
· In general, arthroscopic surgery for debridement is usually not recommended for OA.
· However, arthroscopic surgery to repair cartilage or ligament tears or remove bone bits or cartilage is effective.
Last resort: Joint replacements (arthroplasty)
