Indication
Diagnostic
Pain / Stiffness / Locking
Instability
- exclude OCD
Assess syndesmosis
Therapeutic
Synovitis
Osseous lesions / Tibiotalar impingement spurs
Osteochondral defects
Anterolateral impingement lesions (soft tissue)
Loose bodies
Technique
Set up
Position
- supine on table
- tourniquet
Traction
A. Assistant provide traction
B. Foot traction halter
C. Skeletal distracter
Instrumentations
- standard knee scope or
- 2.7mm 30° scope
- small scope better for getting across joint line without chondral damage
Portals
Ankle distended first
- 20 ml syringe, normal saline
- anteromedial
- insert needle, move ankle
- if on bone and needle moves, on talus and need to redirect proximally
- if on bone and needle doesn't move, on tibia and need to redirect inferiorly
- insufflate with 15 mls to create anterior space
Portals
- usually want instrumentation on side of pathology
- exception is anterior spurs
- usually large osteophyte laterally so first portal insert medially
Anterolateral
- lateral to peroneus tertius
- can then transilluminate and avoid saphenous nerve on AM portal
- structure at risk is branches SPN
- Just proximal to joint line
- incision in skin only
- blunt dissect down to capsule
- insert blunt trochar
- aim anterior to joint to create space
Anteromedial
- second portal
- medial to tibialis anterior
- structure at risk is G saphenous vein and saphenous nerve
- use transillumination to avoid
- insert and visualise needle
- skin incision, blunt dissection
- insert shaver, again anteriorly
- clear soft tisse until can visualise joint line
- beware anterior tendons and nerves
Technique
1. Inspect anterior talus
- plantarflex foot
- look for chondral lesions
2. Inspect distal tibia
- look for osteophytes
3. Inspect gutters
A. Medial
B. Lateral
- exclude meniscoid lesions
4. Look across joint
- distract
- insert probe or shaver and use as level
- look at tibial plafond and syndesmosis
5. Inspect syndesmosis
- probe and assess stability
6. Inspect posterior joint line
Posterior Ankle Arthroscopy
Posterolateral
- just lateral to tendo achilles
- medial to fibular
- 1.2-1.5cm above tip of fibula
- sural nerve & vein anterior
- remember joint 1cm higher at back
Subtalar Arthroscopy
Complications
Nerve Injury
Specific
Anterolateral portal - SPN
Anteromedial portal - Saphenous
Posterolateral portal - Sural
Anterocentral - Deep Peroneal
Posteromedial - Posterior Tibial
Minimise by
1. Marking of skin prior to arthroscopy
2. Transillumination to visualise nerves
3. Feel nerve
4. Use of blunt dissection
Mechanism injury
- penetration
- neural structures close to capsule
- anterior penetration by chondrotome may injure DPN
- traction device
- pins in talus and calcaneus may injure sural nerve
Other
Compartment syndrome
- From extravasation of fluid into calf
Articular cartilage damage
Infection
Pseudoaneurysm