MSK: PART 2

Osteoarthritis (OA) and Rheumatoid Arthritis (RA) are chronic joint disorders, defined as lasting over 6 months. OA is a degenerative joint disease, a 'wear and tear' condition, while RA is an autoimmune inflammatory disease where the body attacks itself. Despite their differences, nursing care goals are similar: pain management, joint protection, and promoting mobility and independence. A healthy synovial joint features bones covered by articular cartilage acting as a shock absorber, a synovial membrane producing lubricating fluid, and a wide joint space for smooth movement without friction.

OA is a degenerative joint disease characterized by the progressive breakdown of cartilage, primarily due to wear and tear, aging, repetitive stress, or joint injury. This loss of cartilage removes the natural shock absorption between bones, leading to pain and inflammation as bones rub against each other. The body attempts to repair damage by forming osteophytes (bone spurs) at joint edges, causing deformity and limited movement. Cartilage loss also leads to joint space narrowing, visible on X-rays, resulting in severe pain, restricted mobility, and stiffness.

Key risk factors for OA include aging, where cartilage naturally degenerates, and obesity, as excess weight increases stress on joints like the knees. Joint injuries from repetitive stress occupations (farming, construction) or sports also increase OA risk. Clinical manifestations include joint pain and stiffness, commonly affecting large joints such as hips, knees, and hands. A hallmark of OA pain is that it worsens with activity but improves with rest. Patients may experience crepitus—a grating or crackling sound—during movement due to bone-on-bone contact or damaged cartilage. Characteristic bony enlargements of finger joints are Heberden's nodes (distal interphalangeal joints) and Bouchard's nodes (proximal interphalangeal joints), resulting from bone overgrowth due to cartilage damage.

Nursing interventions for OA aim to reduce pain and preserve joint function. These include weight reduction to lessen joint pressure, joint protection by avoiding excessive stress and using assistive devices, and pain management with analgesics, NSAIDs, and physical therapy. In severe cases, patients may undergo arthroplasty (joint replacement surgery).

Unlike OA, RA is an autoimmune disorder where the immune system attacks the synovial membrane of joints, leading to inflammation. This causes excess, cloudy synovial fluid with increased white blood cells. RA results in chronic systemic inflammation affecting the entire body. Symptoms include joint pain and swelling, primarily in small joints like hands and wrists, distinguishing it from OA, which affects large joints.

In RA, pain is typically worse after prolonged rest and improves with activity, as inflammation is more pronounced during inactivity. As a systemic inflammatory disease, RA can cause fatigue, anorexia, and weight loss. Long-term inflammation can lead to permanent joint deformities, such as swan neck deformity, where the PIP joint hyperextends and the DIP joint flexes. This abnormal positioning severely impairs hand function and mobility.

Diagnosis of RA involves arthroscopy with synovial fluid aspiration. Cloudy synovial fluid with increased WBCs indicates inflammation. Laboratory analysis of the aspirated fluid may show a positive rheumatoid factor (RF) or elevated levels (approximately 60 IU/mL). Elevated ESR (erythrocyte sedimentation rate) and CRP (C-reactive protein), both inflammatory markers, also suggest RA.

Nursing interventions for RA focus on managing pain and preventing complications. This includes administering DMARDs (e.g., methotrexate) and biologics (e.g., Enbrel, adalimumab), which suppress the immune system. Nurses must monitor for infection signs (fever, sore throat) due to immunosuppression. Patients must test negative for TB before starting biologics. Fatigue management involves rest during flares and splinting joints to prevent contractures, advising patients to sleep with a small, flat pillow, avoiding placing pillows under the knees. Patient teaching covers pain management techniques like applying cold compresses for swelling and hot compresses for pain/stiffness, and using analgesics/corticosteroids. Joint protection involves low-impact exercises, assistive devices (canes, Velcro fasteners), electrical openers, and long-handled hairbrushes. Patients should avoid prolonged standing, heavy lifting, and repetitive motions like knitting/typing, using large joints for tasks instead of small ones (e.g., pressing water from a sponge instead of wringing). Emotional support for altered body image and coping with chronic illness is vital. If chronic pain persists, synovectomy (removal of joint lining) or arthroplasty (joint replacement surgery) may be considered. Boutonniere deformity, another RA-related deformity, involves a flexed PIP joint and hyperextended DIP joint.

OA results from joint degeneration due to repetitive stress, while RA is an autoimmune disease causing systemic inflammation. In OA, pain worsens with activity and improves with rest; in RA, pain is worse after prolonged rest and improves with activity. Morning stiffness in OA is less than 30 minutes, but in RA, it can last over an hour. OA typically affects large, weight-bearing joints asymmetrically, like knees and hips. RA affects small joints symmetrically, such as fingers and wrists. OA primarily has localized joint findings, whereas RA causes systemic inflammation, leading to fatigue, anorexia, weight loss, and increased inflammatory markers like ESR and CRP.