Posterolateral Approach to the Ankle

Posterolateral approach to the ankle, with the posterior malleolar fragment seen in the interval between the peroneal tendons and flexor hal
Posterolateral approach to the ankle, with the posterior malleolar fragment seen in the interval between the peroneal tendons and flexor hallucis longus. Image from Duan X, Kadakia AR. Operative Treatment of Posterior Malleolar Fractures. Open Orthop J. 2017, 11, 732-742. CC BY 4.0.
Gray’s Anatomy illustration of the tendon sheaths on the lateral ankle
Synovial sheaths of the tendons around the ankle from the lateral side. The posterolateral approach passes between the peroneal tendons and flexor hallucis longus. Image by Henry Vandyke Carter, Gray’s Anatomy (1918), Wikimedia Commons, public domain.

Indications

  • ORIF posterior malleolar Fracture
  • Excision of sequestra
  • Removal of benign tumours
  • Arthrodesis of posterior facet of subtalar joint
  • Posterior capsulotomy & syndesmotomy of ankle
  • Elongation of tendons

Position

  • prone
    • longitudinal pads under pelvis & chest
    • abdomen free
  • exsanguinate
  • tourniquet

Landmarks

  • lateral malleolus
  • achilles tendon

Incision

  • 10cm incision halfway between posterior border of lateral malleolus & lateral border of achilles tendon
  • Start: level with tip of fibula
  • End: extend it proximally

Internervous Plane

Superficial Dissection

  • Mobilise skin flaps
  • Beware
    • Short saphenous vein
    • Sural nerve
    • These run behind the lateral malleolus & should be well anterior of the incision
  • Identify 2 peroneal tendons
    • Peroneus brevis
      • anterior to longus
      • muscular almost down to ankle
  • incise peroneal retinaculum to release tendons
  • retract muscles laterally & anteriorly to expose FHL
    • FHL
      • most lateral of deep flexor muscles of calf
      • muscle to joint

Deep Dissection

  • Reflect part of FHL off fibula & retract it medially
  • To reach distal tibia
    • Incise periosteum & strip it medially
  • To enter ankle joint
    • Follow posterior aspect of tibia to posterior ankle joint capsule & incise it transversely

Dangers

  • Short saphenous vein
  • Sural nerve

Procedure

  • Proximally
    • Identify plane between lateral head of gastrocnemius & peroneal muscles
    • Retract soleus with gastrocnemius medially
    • Reflect FHL medially off fibula

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.