Definition
Disorder of immune system
- antigen-antibody complexes
- stimulate release of proteolytic enzymes
- leading to vasculitis, synovitis and cartilage destruction
Characterised
Articular Effects
- synovitis
- ligamentous and capsular laxity
- cartilage destruction
- osseous erosion
Vasculitis
- rheumatoid nodules
- digital ischaemia
- skin ulceration
- poor wound healing
Neuropathy
- mononeuritis multiplex
General
90% will have foot problems
Forefoot
Most commonly involves forefoot
- 10x more common than hindfoot
1. Hallux Valgus
2. Dorsal Subluxation MTPJ
3. Clawing of toes
Midfoot
TNJ OA
Hindfoot
STJ > AKJ
A. STJ / Planovalgus (50%)
- destruction of soft tissues especially STJ capsule and interosseous ligament
- + Destruction of TNJ
- leads to Planovalgus foot
- May be initiated or exacerbated by rupture of Tibialis Posterior (common)
- hindfoot valgus leads to T Achilles contracture
B. Ankle
- Rarely affected (10%)
- Destroyed Ankle rarely occurs in isolation
- i.e. typically would have pan-talar arthritis
Management
Multiple Joint Surgery Timing
1. Forefoot OT
- great symptomatic relief
- minimal patient stress
- eliminates pedal sepsis
- wound problems common & occur before prostheses implanted
2. THR
- easier to rehabilitate following THR with deformed knees
- allows correction of proximal limb contractures & lordosis
3. TKR
4. Hindfoot OT
- usually for planovalgus
Pre-operative
Vascular assessment
- ABI > 0.7
- ankle pressure > 90 mmHg
Examine for neuropathy
Medications
- stop MTX
- ? stop steroids
Infection prevention
- clean skin meticulously prior to surgery
- repeat in OT
- prophylactic ABx for 72hrs
C spine x-ray
Post operatively
Leave sutures in for 3/52 due to delayed healing on steroids
- elevate feet for 2-3/7 post-op
- change dressing that evening if large drainage or oedema