Basic principles

1. Rest/analgesia/activity modification
2. Some joints may benefit from splinting e.g. rheumatoid hands, thumb CMC OA
3. Steroid injections may provide temporary relief
4. Surgery - fusion, replacement, excision

Arthroplasty

• Involves either replacement of part of the joint (hemiarthroplasty) or the whole joint (total joint replacement)

Choice of materials

• Joint replacements can be made of stainless steel, cobalt chrome, titanium alloy, polyethylene and ceramic
• Components may or may not be cemented (bone cement - PMMA) - advantages and disadvantages of both
• The surfaces can consist of a metal‐polyethylene, ceramic‐polyethylene, ceramic–ceramic or metal‐metal bearing couple
• There is no single ideal material or combination of materials for a joint replacement
• Ultimately the joint replacement will fail due to loosening (caused by wear particles producing an inflammatory response or high stresses) or breakage of the joint replacement components
• Metal particles can cause an inflammatory granuloma (known as a pseudotumour) which can cause muscle and bone necrosis
• Polyethylene particles can cause an inflammatory response in bone with subsequent bone resorption (osteolysis) resulting in loosening
• Ceramics can shatter with fatigue due to their brittleness

Indications for a Total Knee Replacement

• Only for older, medically fit appropriate patient with end stage arthritis and severe pain refractory to chronic management
  • Constant severe pain, sleep disturbance, pain limiting function/walking distance, frequent bad 'flare-ups'
  • Those with milder OA and severe pain tend not to do well - increased chance of developing chronic pain
• Older patient where replacement will last for good - 60+ as a guide
  • Expect TKR to last 15-20 years in older, low demand patients if put in well

Indications for a Total Hip Replacement