Posterolateral Approach to the Ankle

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
exanguinate
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

Peroneus brevis (superficial peroneal nerve)
FHL (tibial nerve)

Superficial Dissection

Mobilize 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 grastronemius & peroneal muscles
- Retract soleus with gastrocnemius medially
- Reflect FHL medially off fibula