Arthritis, Joint Replacement and Mobility Aids
OA vs. RA, hip and knee replacement, canes, crutches and walkers
| Osteoarthritis (OA) | Rheumatoid arthritis (RA) | |
|---|---|---|
| Cause | Cartilage wear | Autoimmune inflammation of the joint lining |
| Joints | Weight-bearing joints (hips, knees, spine), often one side | Small joints, symmetric (hands, wrists, feet) |
| Stiffness | Morning stiffness <30 min; pain worse with use | Morning stiffness >1 hour; better with movement |
| Other signs | Bony nodes: Heberden's (end finger joints), Bouchard's (middle joints) | Fatigue, fever, nodules, swan-neck and ulnar deviation deformities; RF and anti-CCP positive |
| Treatment | Exercise, weight loss, acetaminophen, topical or oral NSAIDs, injections, joint replacement | DMARDs early: methotrexate (folic acid, no alcohol, liver and blood tests, birth defects), biologics (TNF inhibitors: TB screening, no live vaccines), JAK inhibitors; short-term steroids |
Total hip replacement
- Follow the surgeon's precautions: they depend on the approach.
- Posterior approach (classic): no hip flexion >90°, no crossing legs (adduction), no turning the leg inward; abduction pillow; raised toilet seat; chair with arms.
- Anterior approach: fewer restrictions (avoid extending and turning the leg out).
- Dislocation: sudden severe pain, shortened or rotated leg, can't move it → notify.
- DVT prophylaxis, early walking, infection signs.
Total knee replacement
- Early physical therapy and walking; work toward full extension and flexion.
- Pain control before PT sessions; ice.
- Don't put a pillow under the knee (causes contracture).
- DVT prophylaxis; watch the incision; neurovascular checks.
Mobility aids
Cane
Held on the strong side (opposite the weak leg). Move the cane and weak leg together. Top at hip level; elbow bent ~15–30°.
Crutches
Top 2–3 finger widths (1–2 in) below the armpit; weight on the hands, not the armpits; elbows bent 20–30°. Gaits: 3-point (non-weight-bearing), 2-point, 4-point, swing-through.
Walker
Lift (or roll) it forward ~6–10 in, step into it with the weak leg first, then the strong leg. Don't use it on stairs.
Memory hook: stairs"Up with the good, down with the bad." Going up: strong leg first, then crutches/cane and weak leg. Going down: crutches/cane and weak leg first.
Osteoporosis
DEXA scan: T-score ≤ −2.5 = osteoporosis (−1 to −2.5 = low bone mass). Calcium and vitamin D, weight-bearing and resistance exercise, fall prevention, no smoking, limit alcohol; medications (see Part 1, Pharmacology).