Ankle Sprains

Aetiology

  • Commonly due to 'twisted ankle'

Pathophysiology

Lateral ankle sprains (85%)

  • Most commonly due to inversion of the plantar flexed foot, which leads to excessive supintion of the rearfoot about an externally rotated leg
  • AFTL (weakest ligament) injured first
  • CFL has ~3x higher load to failure than AFTL
  • PFTL rarely torn
notion image

Grading of ankle sprains

  • Grade 1: microscopic tear (stretch)
  • Grade 2: partial tear
  • Grade 3: complete rupture
  • Chronic sprains: recurrent sprains or giving way, persisting for more than 6 months

Clinical presentation

  • Tenderness and swelling
  • Bruising
  • Functional loss e.g. pain on weight-bearing
  • Mechanical instability

Investigations

  • X-ray to rule out fracture

Management

  • Initial management - protection, rest, ice, compression and elevation (PRICE)
  • Most patients have an element of functional instability
    • Phyio first
    • Arthroscopy for pain
    • Reconstruction if needed