Rheumatoid foot

Clinical image

Radiograph of feet affected by rheumatoid arthritis. Source: Wikimedia Commons — Lariob; CC BY-SA 4.0. Image binary is embedded locally in this package; original source and licence are retained.

Key points

Deformities

• Forefoot
• Hind foot
• Soft tissue

Fore foot

• Hallus valgus
• 1st MTP joint erosive arthritis
• Dorsal sub/dis of MTP joint (Synovitis, plantar plate laxity)
• Prominent MT head in the sole (callosities)
• Hammer and claw toes (intrinsic contracture)

Hind foot

• Valgus ankle and instability
• Valgus hind foot due to subtalar arthritis
• Medial arch collapse and foot pronation (TN subluxation)
• Subfibular impingement

Soft tissue

• Tenosynovitis TP and Peroneals: ankle swelling
• Medial arch collapse: TP rupture and TC ligament
• Distal migration of fore foot fat pad
• TT syndrome
• Morton neuroma
• Retrocalcaneal buristis

C/E

• History:
  • Drug
• Hip and Knee problems to be addressed first
• Look
  • Skin, deformity
• Feel
  • Pulse
  • Neurology
  • Tenderness
• Move
  • Joint involvement
  • Tendon rupture

MDT approach

• Special shoes/footwear
• Accommodating orthosis
• Steroid inj
• DMARD
• Surgery goal
  • Stable pain free plantigrade foot
    • Both hindfoot and forefoot involved
      • Hind foot flexible: forefoot first
      • Hindfoot rigid: Hind foot first

Forefoot

• 1st MTPJ arthrodesis (10 degree DF, 10 degree valgus)
• 2-5 MT head resection (fowler)
• Realign lesser toes
• Main compli is recurrence
• Pobble amputation: 2-4 toe resection

Hind foot

• Triple arthrodesis
• TTC arthrodesis FABER (0,5,10)
  • Cannulated screw
  • Plate
  • Retrograde Nail
  • Ex Fix
  • Arthroscopy
• Artroplasty: STAR 10 year survival 80%
• Both arthrodesis and arthroplasty has similar intermediate and long term outcome but TAR has more complications