osteoarthritis

Question 1

what is osteoarthritis?

Answer 1

degenerative joint disorder in which there is progressive loss of hyaline cartilage + new bone formation at the joint surface + its margine

Question 2

what are risk factors for osteoarthritis?

Answer 2

age >75
female
obesity
joint abnormality- developmental dysplasia of the hip

Question 3

what are the classifications of osteoarthritis?

Answer 3

primary- no underlying cause
secondary- obesity, joint abnormality

Question 4

what are the symptoms of osteoarthritis?

Answer 4

• Affects: knees, hips, DIPs, PIPs, thumb CMC
• Pain: worse w movement, improved by rest,
  worse at end of day
• Stiffness: especially after rest, lasts ~30min in morning-
  >2 hours may suggest inflammatory cause
• Deformity
• ↓ROM

Question 5

what are red flag symptoms of joint pain?

Answer 5

rest pain
night pain
morning stiffness>2hrs

Question 6

what system is used to assess severity?

Answer 6

oxford hip score

Question 7

what are the sign of osteoarthritis?

Answer 7

• Bouchards (prox) and Heberdens (dist) nodes
• Thumb CMC squaring
• Fixed flexion deformity

Question 8

what is the history of osteoarthritis?

Answer 8

• Pain severity, night pain
• Walking distance
• Analgesic requirements
• ADLs and social circumstances
• Co-morbidities
• Underlying causes: trauma, infection, congenital

Question 9

what is the pathophysiology of osteoarthritis?

Answer 9

• Softening of articular cartilage → fraying and fissuring of smooth surface → underlying bone exposure.
• Subchondral bone becomes sclerotic w cysts.
• Proliferation and ossification of cartilage in unstressed
  areas → osteophytes.
• Capsular fibrosis → stiff joints.

Question 10

what investigations are needed to diagnose OA?

Answer 10

can be clinical if typical features
otherwise X Ray

Question 11

what are the X ray changes in osteoarthritis?

Answer 11

• Loss of joint space * Osteophytes
• Subchondral cysts
• Subchondral sclerosis * Deformity

Question 12

what are the blood test results in osteoarthritis?

Answer 12

• CRP may be mildly elevated
• Ca, PO4 and ALP all normal

Question 13

what is the conservative management of osteoarthritis?

Answer 13

MDT- GP, OT, physio, dietician, ortho

• Lifestyle: ↓ wt., ↑ exercise
• Physio: muscle strengthening
• OT: walking aids, supportive footwear, home mods

Question 14

what is the medical management of osteoarthritis?

Answer 14

• Analgesia
  -Paracetamol
  -NSAIDs: e.g. arthrotec (diclofenac + misoprostol)
  -Tramadol
• intra-articular injections: local anaesthetic and steroids

Question 15

what is the definitive treatment of OA?

Answer 15

total hip replacement

Question 16

what are the complications of total hip replacement?

Answer 16

1. perioperative
   - venous thromboembolism
   - intraoperative fracture
   - nerve injury
   - surgical site infection
2. leg length discrepancy
3. posterior dislocation
   - may occur during extremes of hip flexion
   - typically presents acutely with a ‘clunk’, pain and inability to weight bear
   - on examination there is internal rotation and shortening of the affected leg

• aseptic loosening (most common reason for revision) -> prosthetic joint infection

Question 17

what is the surgical management of osteoarthritis?

Answer 17

1. athroscopic washout- mainly knees, trim cartilage, remove loose bodies
2. realignment osteotomy
   - small area of bone cut out, useful in younger <50 w medial knee OA
   - high tibial valgus osteotomy redistributes weight to lateral part of joint
3. arthroplasty- replacement/excision
4. arthrodesis- last resort for pain management
5. novel techniques:
   - microfracture- stem cell release leads to fibrocartilage formation
   - autologous chondrocyte implantation