Ankle Arthroscopy

Surgical Indications

Anterior Ankle Arthroscopy

• Anterior bony or soft-tissue impingement refractory to at least 3 months of conservative treatment
• Osteochondral lesions of the talus (OLT) accessible from anterior portals (typically anterolateral or central talar dome)
• Loose bodies within the anterior or central ankle joint
• Synovitis or arthrofibrosis limiting motion after trauma or previous surgery
• Assisted reduction and fixation of certain intra-articular fractures (e.g. Tillaux, Chaput fragments)
• Diagnostic arthroscopy when MRI is equivocal and symptoms persist

Posterior Ankle Arthroscopy

• Posterior impingement (os trigonum, Stieda process, posterior talar process fracture non-union)
• Flexor hallucis longus tenosynovitis or stenosis
• Posterior loose bodies or osteochondral lesions not accessible anteriorly
• Posterior ankle arthrofibrosis or capsular contracture
• Assisted posterior ankle fusion in selected cases

Absolute Contraindications

• Active septic arthritis or open wound at portal sites
• Severe ankle arthritis with less than 50 percent joint space remaining (consider arthrodesis)
• Vascular insufficiency precluding tourniquet use or wound healing

Relative Contraindications

• Previous extensive open surgery with distorted anatomy
• Complex regional pain syndrome (may worsen with arthroscopy)
• Patient unable to comply with post-operative rehabilitation

Evidence Summary

Key Evidence

Anterior Ankle Joint Anatomy Relevant to Arthroscopy

Joint Access and Capsular Landmarks

• The anterior ankle joint capsule attaches approximately 5-8 mm proximal to the tibial plafond and 8-12 mm distal to the talar dome articular margin
• The anterior gutter and both medial and lateral gutters must be inspected systematically
• The talar dome articular surface is visible from anterior portals with distraction; the posterior 20-30 percent of the talus requires posterior portals or 70-degree scope

Anteromedial Portal

• Located immediately medial to the tibialis anterior tendon at the level of the joint line
• Structures at risk: saphenous vein and nerve (lie 3-5 mm medial to the portal)
• Established first under direct vision after anterolateral portal and scope insertion in most techniques

Anterolateral Portal

• Located lateral to the peroneus tertius or extensor digitorum communis tendon, just lateral to the talar dome
• Structures at risk: superficial peroneal nerve (intermediate dorsal cutaneous branch) — crosses 8-15 mm proximal to joint line in most ankles
• Transillumination with the ankle in plantarflexion and inversion is mandatory before incision

Posterior Ankle Joint Anatomy Relevant to Arthroscopy

Prone Position Landmarks

• The Achilles tendon is the central landmark; portals are placed immediately on either side
• The flexor hallucis longus tendon is the critical medial boundary for safe posterior work
• The posterior tibial neurovascular bundle lies within the tarsal tunnel, medial and slightly anterior to the FHL tendon

Posterolateral Portal

• Placed immediately lateral to the Achilles tendon at the level of the posterior joint line (approximately 1.5-2 cm proximal to the tip of the lateral malleolus)
• Structures at risk: sural nerve and small saphenous vein (lie 1-2 cm lateral to the portal)
• First posterior portal created; allows initial visualisation of the posterior compartment

Posteromedial Portal

• Placed immediately medial to the Achilles tendon under direct vision from the posterolateral scope
• Structures at risk: posterior tibial neurovascular bundle (medial to FHL); FHL tendon itself
• All instrumentation stays strictly lateral to the FHL tendon; the safe working space is the interval between the FHL and the peroneal tendons

Positioning and Preparation

Patient position: Supine for anterior arthroscopy with non-invasive distraction strap applied to the foot and attached to a distractor or sandbag. For combined anterior and posterior work, the patient is positioned prone after anterior arthroscopy is complete, or a single posterior procedure is performed prone from the outset.

Anaesthesia: General or spinal anaesthesia with a thigh tourniquet at 250-300 mmHg. Regional ankle block can be added for post-operative analgesia. Prophylactic antibiotics are given at induction.

Equipment: 2.7 mm or 4.0 mm 30-degree arthroscope (4.0 mm preferred for posterior work), non-invasive distraction device or padded strap, radiofrequency ablation device, 3.5 mm or 4.5 mm shaver, microfracture awls, curved curettes, and a 70-degree scope for posterior visualisation.

Consent: Counsel regarding risk of nerve injury (2-5 percent temporary, less than 1 percent permanent), incomplete resolution of impingement, iatrogenic chondral injury, infection (less than 1 percent), and the possibility of conversion to open surgery.

Anterior Ankle Arthroscopy — Step-by-Step

Step 1: Portal Placement — Anterolateral First

With the ankle distracted, mark the joint line by palpation. Transilluminate the proposed anterolateral portal site with the ankle in plantarflexion and inversion to identify the superficial peroneal nerve. Make a vertical 5 mm skin incision just lateral to the peroneus tertius tendon. Use a haemostat to spread bluntly down to the capsule, then insert a blunt trocar and cannula.

Step 2: Anteromedial Portal under Direct Vision

Insert the 30-degree scope through the anterolateral portal and inspect the anterior joint. Identify the tibialis anterior tendon. Make the anteromedial portal immediately medial to the tendon under direct intra-articular vision using an 18-gauge needle first to confirm position. Spread bluntly and insert the cannula.

Step 3: Systematic Diagnostic Arthroscopy

Perform a systematic inspection: medial gutter, medial talar dome, central talar dome, lateral talar dome, lateral gutter, anterior tibial plafond, and anterior capsule. Document any chondral lesions, loose bodies, synovitis, or impingement lesions with a probe.

Step 4: Resection of Anterior Impingement

Use a 3.5 mm shaver or radiofrequency probe to resect anterior osteophytes and hypertrophic synovium from the tibial plafond and talar neck. Preserve at least 50 percent of the talar dome articular surface. Remove loose bodies with a grasper.

Step 5: Treatment of Osteochondral Lesions

For contained OLT less than 15 mm, debride unstable cartilage flaps with a curette, then perform microfracture with 2 mm awls spaced 3-4 mm apart to a depth of 3-4 mm until fat droplets appear. For larger or uncontained lesions, consider OATS or ACI after discussion.

Posterior Ankle Arthroscopy — Step-by-Step

Step 1: Prone Positioning and Portal Placement

Position the patient prone with non-invasive distraction. Mark the Achilles tendon and the level of the posterior joint line. Create the posterolateral portal immediately lateral to the Achilles tendon. Insert the scope and identify the FHL tendon.

Step 2: Posteromedial Portal under Direct Vision

With the scope in the posterolateral portal, identify the FHL tendon. Create the posteromedial portal immediately medial to the Achilles tendon under direct vision, staying lateral to the FHL. Insert a cannula.

Step 3: Posterior Compartment Work

All work occurs in the safe interval lateral to the FHL tendon. Resect os trigonum or posterior talar process with a shaver or burr. Debride FHL tenosynovitis. Remove posterior loose bodies. Inspect the posterior talar dome and tibial plafond.

Step 4: Closure and Dressing

Close portals with 3-0 nylon or absorbable suture. Apply sterile dressing and posterior splint if microfracture was performed; otherwise a compression bandage suffices.

Immediate Post-operative Protocol (Day 0-14)

• Dressing and wound care: Keep portals dry for 48 hours. Remove dressings at 48 hours and begin daily portal cleaning with chlorhexidine.
• Weight bearing: Touch weight bearing for 48 hours, then progress to full weight bearing as tolerated unless microfracture was performed.
• Range of motion: Begin active ankle dorsiflexion, plantarflexion, inversion and eversion from day 1. No formal immobilisation unless microfracture or ligament repair performed.
• Analgesia: Paracetamol and NSAIDs; short course of opioids if required. Ice and elevation for 48-72 hours.
• Suture removal: 10-14 days.

Microfracture-Specific Protocol

• Non-weight bearing for 6 weeks in a removable boot or cast.
• Continuous passive motion device for 6 hours daily during the non-weight-bearing phase.
• Begin active range of motion from week 2.
• Progressive weight bearing from week 6 with physiotherapy supervision.
• Return to running at 4-6 months; return to sport at 6-9 months depending on lesion size and sport demands.

Return to Function and Sport

• Sedentary work: 1-2 weeks
• Manual labour: 4-6 weeks
• Running and impact sports: 3-4 months for impingement resection; 6-9 months for microfracture
• Professional athletes: Individualised; anterior impingement resection often allows return by 8-12 weeks with structured rehabilitation

Physiotherapy Milestones

• Week 2: Full active range of motion, scar massage, proprioception training
• Week 6: Strengthening (theraband, isometrics), gait normalisation
• Week 12: Sport-specific drills, plyometrics if microfracture healed
• Ongoing: Maintenance proprioception and peroneal strengthening to prevent re-injury