import { ComparisonTable, ContentSection, EvidenceCard, ExamCheatSheet, ExamPearl, ExamWarning, InfoCard, InfoCardGrid, MedicalImage, MnemonicCard, OnePagerSummary, SafetyAlert, Tab, Tabs, Timeline, TimelineItem, VivaScenario, VivaScenarioSection } from '@/components/mdx' {/* SECTION 1: ONE-PAGER SUMMARY */} {/* SECTION 2: EXAM WARNING */} **Deep peroneal nerve and anterior tibial artery** travel together, 1-2cm lateral to extensor hallucis longus at ankle level. CRITICAL: Identify bundle early, retract medially WITH the EHL tendon. Injury rate 1-3% if not protected systematically. **Superficial peroneal nerve branches** emerge from lateral compartment approximately 10-12cm proximal to lateral malleolus. These HIGHLY variable branches cross surgical field. Identify during skin incision, protect with vessel loops. Injury causes lateral dorsal foot numbness and painful neuroma. Interval between **tibialis anterior** (medial) and **extensor hallucis longus** (lateral). Both muscles supplied by deep peroneal nerve - technically NOT a true internervous plane. Safe because nerve travels WITH EHL laterally, so dissection medial to nerve is safe. **Extensor retinaculum must be repaired** at closure with strong sutures (0 Vicryl). Failure to repair causes tendon bowstringing during dorsiflexion, resulting in loss of mechanical efficiency and functional deficit. Tag edges at beginning for easier repair. {/* SECTION 3: MNEMONICS */} The **anterior ankle approach** provides access for ankle arthrodesis, total ankle arthroplasty, and distal tibial/talar fracture fixation through the interval between **tibialis anterior and extensor hallucis longus (EHL)**. The **deep peroneal nerve and anterior tibial artery** travel together **1-2cm lateral to EHL** at ankle level—they must be identified early and retracted medially WITH the EHL to prevent injury (1-3% risk). The **superficial peroneal nerve** branches emerge 10-12cm proximal to the lateral malleolus and cross the field laterally (3-5% injury rate). Although both TA and EHL are supplied by the deep peroneal nerve (not a true internervous plane), dissection is safe because the nerve travels laterally with EHL. **Extensor retinaculum repair is essential** at closure to prevent tendon bowstringing. {/* SECTION 4: OVERVIEW AND INDICATIONS */} {/* MISSING IMAGE: /images/topics/ankle-anterior-approach/web-sourced/3-challenges-in-ultrasound-images-of-atfl-a-atfl-ana.png {/* MISSING IMAGE: /images/topics/ankle-anterior-approach/web-sourced/3-challenges-in-ultrasound-images-of-atfl-a-atfl-ana.png */} */} {/* MISSING IMAGE: /images/topics/ankle-anterior-approach/web-sourced/2-axial-slices-of-a-computed-tomography-of-the-ankle.png {/* MISSING IMAGE: /images/topics/ankle-anterior-approach/web-sourced/2-axial-slices-of-a-computed-tomography-of-the-ankle.png */} */} {/* MISSING IMAGE: /images/topics/ankle-anterior-approach/web-sourced/1-dynamic-us-examination-of-the-aitfl-in-order-to-st.png {/* MISSING IMAGE: /images/topics/ankle-anterior-approach/web-sourced/1-dynamic-us-examination-of-the-aitfl-in-order-to-st.png */} */} **The anterior approach to the ankle** provides direct access to the tibiotalar joint through a relatively safe interval between the tibialis anterior and extensor hallucis longus tendons. This approach exploits the superficial nature of the anterior ankle anatomy and the predictable course of neurovascular structures. ### Why This Approach? **Advantages:** - **Direct visualization** of anterior tibial plafond and talar dome - **Extensile** - can be extended proximally to tibial shaft or distally to talar neck - **Relatively safe** neurovascular structures if technique systematic - **Minimal muscle dissection** - interval between tendons, no muscle cutting required - **Good bone access** for implant placement in arthrodesis and arthroplasty **Disadvantages:** - **Cannot access posterior ankle** - requires separate posterior approach for posterior pathology - **Superficial peroneal nerve at risk** - variable anatomy makes injury possible - **Wound healing concerns** - thin soft tissue envelope over anterior ankle - **Limited lateral access** - cannot safely extend to lateral malleolus through same incision ### Primary Indications **Ankle Arthrodesis:** - End-stage post-traumatic arthritis with pain and disability - Inflammatory arthropathy (rheumatoid arthritis, psoriatic arthritis) with joint destruction - Failed total ankle arthroplasty requiring salvage fusion - Significant ankle deformity requiring correction (varus, valgus, equinus) - Neuromuscular conditions with ankle instability and deformity - Avascular necrosis of talus with secondary arthritis **Total Ankle Arthroplasty:** - End-stage ankle arthritis in appropriate candidates - Age typically over 50 years with lower physical demands - Neutral or correctable alignment (within 15 degrees varus/valgus) - Adequate bone stock for component fixation - Absence of significant comorbidities (peripheral vascular disease, neuropathy) - Patient preference for motion preservation vs arthrodesis **Fracture Fixation:** - Pilon fractures (tibial plafond fractures) requiring anatomic articular reduction - Displaced talar neck fractures (Hawkins type II, III, IV) - Talar body fractures with articular involvement - Displaced anterior process talus fractures - Malunion or nonunion of distal tibia or talus requiring revision **Other Indications:** - Osteochondral lesions of anterior talar dome (greater than 1.5cm, uncontained) - Anterior ankle impingement syndrome with large osteophytes - Septic arthritis requiring formal washout and debridement - Synovectomy for inflammatory arthropathy - Removal of loose bodies or failed hardware ### Contraindications **Absolute:** - Active infection overlying surgical site (unless procedure is infection debridement) - Severe peripheral vascular disease with compromised healing potential (ankle-brachial index less than 0.5) **Relative:** - Poor soft tissue envelope (previous burns, infection, radiation, compromised skin quality) - Morbid obesity (BMI greater than 40) complicating deep access and wound healing - Severe osteoporosis with inadequate bone for fixation - Active Charcot arthropathy - Unrealistic patient expectations for functional outcomes This approach provides excellent exposure for the most common ankle procedures performed in orthopaedic surgery. {/* SECTION 5: SURGICAL ANATOMY */} ### Surgical Anatomy for Anterior Ankle Approach **Surface Landmarks**: - **Anterior tibial tendon**: Most medial and prominent tendon - **Medial malleolus**: Palpable bony prominence medially - **Lateral malleolus**: Distal fibula prominence laterally - **Ankle joint line**: 1cm proximal to tip of medial malleolus - **Extensor retinaculum**: Thickened fascia overlying tendons **Incision Planning**: - Centered between tibialis anterior and EDL tendons - Directly over EHL tendon - Length: 10-12cm for standard exposure **Structures from Medial to Lateral** (TENE mnemonic): | Structure | Position | Surgical Relevance | |-----------|----------|-------------------| | **Tibialis anterior** | Most medial | Retract medially, muscular portion proximally | | **Extensor hallucis longus** | Central | Index tendon, retract with NV bundle | | **Neurovascular bundle** | 1-2cm lateral to EHL | Deep peroneal nerve + anterior tibial artery | | **Extensor digitorum longus** | Lateral | Retract laterally | **Key Relationship**: The neurovascular bundle lies LATERAL to EHL - retract them together MEDIALLY to protect. **Deep Peroneal Nerve**: - Courses with anterior tibial artery - Lies 1-2cm lateral to EHL at ankle level - Supplies: EHL, EDL, EDB, first web space sensation - **Protection**: Retract medially with EHL **Superficial Peroneal Nerve**: - Emerges from lateral compartment 10-12cm proximal to lateral malleolus - Highly variable branching pattern - Branches cross surgical field laterally - **Protection**: Identify during skin incision, retract with vessel loop ### Approach Variations **Standard Anterior Approach**: | Feature | Description | |---------|-------------| | **Incision** | 10-12cm, centered over EHL | | **Interval** | Between tibialis anterior and EHL | | **Retraction** | EHL + NV bundle medially, EDL laterally | | **Uses** | Ankle arthrodesis, TAR, pilon fractures | **Extensile Options**: - **Proximal extension**: Access distal tibial shaft - **Distal extension**: Access talar neck and head - **Cannot extend laterally**: Separate incision for fibula **Approach Modifications by Indication**: | Indication | Modification | |------------|--------------| | **Total Ankle Arthroplasty** | Standard approach, wide exposure for jig placement | | **Ankle Arthrodesis** | May use medially based incision to access medial gutter | | **Pilon Fracture** | Consider extensile proximally for plate placement | | **Talar Neck Fracture** | Extend distally, may add medial malleolar osteotomy | | **OCD of Talus** | Smaller incision adequate for arthrotomy and debridement | **Alternative Approaches**: - **Anteromedial approach**: More medial, between TA and EHL - **Anterolateral approach**: Between EHL and EDL, for lateral pathology **Procedure-Specific Considerations**: **Ankle Arthrodesis**: - Standard anterior approach - May add lateral incision for fibular resection - Consider prone posterior approach for revision **Total Ankle Arthroplasty**: - Strict midline anterior approach - Adequate retraction for jig placement - Attention to soft tissue handling **Fracture Fixation**: - Pilon: May need combination of approaches - Talus: Consider medial malleolar osteotomy for access - Syndesmosis: Separate lateral incision ### History **History for Anterior Ankle Surgery**: - **Pain**: Location, duration, aggravating factors, night pain - **Function**: Walking distance, stairs, sports, ADLs - **Prior surgery**: Previous ankle surgery, hardware in situ - **Comorbidities**: Diabetes, PVD, smoking, immunosuppression - **Medications**: Anticoagulation, steroids, immunosuppressants - **Expectations**: Goals of surgery, activity level desired **Red Flags**: - Active infection - Severe vascular disease - Uncontrolled diabetes ### Examination **Physical Examination**: | Assessment | Key Findings | |------------|--------------| | **Gait** | Antalgic pattern, foot position | | **Alignment** | Varus/valgus deformity, hindfoot position | | **ROM** | Dorsiflexion/plantarflexion, stiffness | | **Stability** | Anterior drawer, talar tilt | | **Tendons** | Tibialis posterior, peroneal function | | **Neurovascular** | Pulses (dorsalis pedis, posterior tibial), sensation | **Soft Tissue Assessment**: - Prior scars and incisions - Skin quality and vascularity - Swelling, venous stasis changes - Hair growth (perfusion indicator) **Pre-operative Planning**: **Patient Optimization**: - Smoking cessation (minimum 4-6 weeks) - HbA1c less than 8% for diabetics - Nutritional optimization (albumin greater than 3.5) - DVT prophylaxis planning **Surgical Planning**: - Confirm indication for anterior approach - Template implants (TAR, arthrodesis hardware) - Plan incision location with previous scars - Prepare for potential intraoperative findings **Consent Discussion**: - Nerve injury risk (deep peroneal 1-3%, superficial 3-5%) - Wound healing concerns - Procedure-specific complications ### Pre-operative Imaging **Standard Radiographs**: | View | Assessment | |------|------------| | **Weight-bearing AP ankle** | Tibiotalar joint space, alignment, osteophytes | | **Weight-bearing lateral** | Dorsiflexion/plantarflexion, anterior osteophytes | | **Mortise view** | Lateral clear space, fibular length | | **Hindfoot alignment view** | Overall hindfoot alignment for planning | **Key Findings**: - Joint space narrowing (arthritis grading) - Osteophyte formation (impingement risk) - Bone quality for fixation planning - Deformity assessment **CT Indications**: - Fracture characterization (pilon, talus) - Subtalar and midfoot arthritis assessment - Bone quality evaluation - Deformity quantification - Failed prior surgery evaluation **CT Assessment**: - Articular surface integrity - Cyst formation and subchondral changes - Hardware position (revision cases) - 3D reconstruction for complex deformity **MRI Indications**: - Osteochondral lesions of talus - Soft tissue assessment (tendons, ligaments) - AVN evaluation - Infection workup **Additional Investigations**: | Investigation | Indication | |---------------|------------| | **Ankle-brachial index** | PVD assessment, poor pulses | | **EMG/NCS** | Pre-existing neuropathy | | **WBC/CRP/ESR** | Infection exclusion | | **HbA1c** | Diabetic optimization | | **Bone density scan** | Osteoporosis concerns | ### Surgical Decision-Making **Ankle Arthrodesis via Anterior Approach**: **Indications**: - End-stage ankle arthritis - Failed total ankle arthroplasty - Avascular necrosis with collapse - Significant deformity - Young, high-demand patient **Technique Highlights**: - Anterior approach for joint exposure - Complete cartilage removal - Position: Neutral dorsiflexion, 5° valgus, slight external rotation - Fixation: Crossed screws, anterior plate, or combination - May require lateral incision for fibular resection **Expected Outcomes**: - Fusion rate: 85-95% - Good pain relief - Functional gait adaptation **Total Ankle Arthroplasty (TAR)**: **Candidate Selection**: - Age typically greater than 50 years - Low-demand activity level - Neutral or correctable alignment - Adequate bone stock - No significant comorbidities **Anterior Approach for TAR**: - Strict midline incision - Wide exposure for instrumentation - Careful soft tissue handling - Retinaculum repair essential **Expected Outcomes**: - 70-85% survival at 10 years - Preserved motion (average 25-35°) - Improved function vs arthrodesis in some **Fracture Fixation via Anterior Approach**: **Pilon Fractures**: - Anterior approach for articular reduction - May combine with posterolateral approach - Staged protocol for soft tissue management - ORIF with anatomic articular reduction **Talar Fractures**: - Talar neck: Anterior approach primary access - May require medial malleolar osteotomy - Anatomic reduction critical to prevent AVN - Early fixation preferred **Post-traumatic Reconstruction**: - Malunion correction - Hardware removal - Secondary procedures for complications ### Safe Interval for Anterior Ankle Approach The anterior ankle approach uses the interval between **tibialis anterior** (medial) and **extensor hallucis longus** (lateral). This is **NOT a true internervous plane** because both muscles are supplied by the same nerve (deep peroneal nerve). However, it is a SAFE interval because the deep peroneal nerve and anterior tibial artery travel LATERAL to EHL - dissection occurs MEDIAL to the neurovascular bundle. **Why It Works:** - Deep peroneal nerve travels in fascial plane LATERAL to EHL - At ankle level: nerve lies 1-2cm lateral to EHL tendon - Dissection is MEDIAL to neurovascular bundle - Retract EHL and nerve together MEDIALLY throughout procedure When asked about the anterior ankle approach in a viva, emphasize: "This is NOT a true internervous plane as both muscles are supplied by deep peroneal nerve. However, it IS safe because the neurovascular bundle lies lateral to EHL and is protected by retracting EHL medially with the nerve." ### Surface Landmarks **Key Palpable Structures:** **Tibialis Anterior Tendon:** - Most medial and prominent anterior ankle tendon - Becomes subcutaneous at ankle level - Easily palpated with foot dorsiflexion and inversion - Inserts on medial cuneiform and base of first metatarsal - **Surgical landmark**: Medial border of approach **Extensor Hallucis Longus Tendon:** - Central anterior ankle structure - Passes to great toe (hallux) - Palpate by asking patient to extend hallux against resistance - **Surgical landmark**: Center of skin incision lies over or just lateral to this tendon **Extensor Digitorum Longus Tendons:** - Multiple tendons passing to toes 2-5 - Lateral to EHL - Palpate with toe extension - **Surgical landmark**: Lateral border of approach **Dorsalis Pedis Pulse:** - Palpable between EHL and EDL tendons at ankle level - Marks position of anterior tibial artery and deep peroneal nerve - **Important**: Absent in 8-12% of normal population (anatomic variation) - **Surgical landmark**: Check pre-operatively and post-operatively **Malleoli:** - Medial malleolus and lateral malleolus provide bony landmarks - Ankle joint line is approximately 1cm distal to tip of malleoli - Used for proximal-distal orientation of incision ### Internervous Plane **The Concept:** The anterior ankle approach uses the interval between **tibialis anterior** (medial) and **extensor hallucis longus** (lateral). **Important caveat**: This is **NOT a true internervous plane** because both muscles are supplied by the same nerve (deep peroneal nerve). However, it is a SAFE interval because: - The deep peroneal nerve travels in the fascial plane LATERAL to EHL - Dissection occurs MEDIAL to the neurovascular bundle - No motor nerve branches cross the plane of dissection - The nerve can be identified and protected by retracting it medially with the EHL **Muscle Innervation:** - Tibialis anterior: Deep peroneal nerve (L4, L5) - Extensor hallucis longus: Deep peroneal nerve (L5, S1) - Extensor digitorum longus: Deep peroneal nerve (L5, S1) Because all three muscles share the same nerve supply, the safety of this approach depends on **systematic identification and protection** of the neurovascular bundle, not on a true internervous dissection. ### Neurovascular Anatomy **Deep Peroneal Nerve:** **Course:** - Originates from common peroneal nerve at fibular neck level - Enters anterior compartment by piercing anterior intermuscular septum - Descends between tibialis anterior and extensor hallucis longus - Lies on interosseous membrane in proximal and mid leg - Moves LATERALLY in distal third of leg - At ankle joint level: positioned 1-2cm lateral to EHL tendon - Depth at ankle: 1-2cm deep to extensor retinaculum **Terminal Branches (at ankle level):** - **Medial branch**: Sensory to first web space (between hallux and second toe) - **Lateral branch**: Motor to extensor digitorum brevis and extensor hallucis brevis **Clinical significance:** - Injury causes foot drop (cannot dorsifl ex ankle or extend toes) - Sensory loss in first web space - Tinel sign at site of injury if neuroma develops **Protection strategy:** - Identify nerve by palpating dorsalis pedis pulse (nerve travels with artery) - Visualize nerve in distal wound during superficial dissection - Retract nerve MEDIALLY with EHL tendon throughout procedure - Gentle retraction only (excessive force causes neuropraxia) - Protect during saw cuts with blade guards and direct visualization **Anterior Tibial Artery:** **Course:** - Originates from popliteal artery in posterior compartment - Passes anteriorly through gap in proximal interosseous membrane - Descends on anterior surface of interosseous membrane - Accompanied by two venae comitantes - Becomes **dorsalis pedis artery** at level of ankle joint - Pulse palpable between EHL and EDL tendons **Clinical significance:** - Provides blood supply to dorsum of foot - Injury can compromise foot perfusion if posterior tibial artery also compromised - Most patients tolerate anterior tibial artery ligation if posterior tibial and peroneal arteries intact **Protection strategy:** - Same as deep peroneal nerve (they travel together) - Identify by palpating pulse or using handheld Doppler - Retract medially with nerve and EHL - If injured: attempt primary repair with 6-0 or 7-0 Prolene OR ligate if foot perfusion adequate **Superficial Peroneal Nerve:** **Course:** - Descends in lateral compartment between peroneus longus and brevis - Emerges through deep fascia approximately 10-12cm proximal to lateral malleolus - Divides into **medial dorsal cutaneous** and **intermediate dorsal cutaneous** nerves - These branches cross anterior ankle subcutaneously - **HIGHLY variable anatomy** - position varies considerably between patients **Branches:** - Medial dorsal cutaneous: Supplies dorsum of foot and medial toes - Intermediate dorsal cutaneous: Supplies lateral dorsum of foot **Clinical significance:** - Injury causes numbness/paraesthesias over dorsum of foot - Neuroma formation causes painful Tinel sign and shooting pains - One of most common nerve injuries in anterior ankle approach (3-5% incidence) **Protection strategy:** - Careful skin incision with identification of any visible nerve branches - Use scalpel perpendicular to skin (avoid beveling which can lacerate nerves) - Mobilize identified nerves gently with blunt dissection - Protect with vessel loops or small retractors - Keep incision centered (more medial incision has lower risk but less access) ### Extensor Retinaculum **Superior Extensor Retinaculum:** - Y-shaped band, 2-3cm wide - Attaches laterally to anterior fibula, medially to anterior tibia - Located approximately 2-4cm proximal to ankle joint - Prevents bowstringing of tendons during dorsiflexion **Inferior Extensor Retinaculum:** - Y-shaped with stem laterally on calcaneus - Creates individual tunnels for each tendon: - Medial: Tibialis anterior (separate tunnel) - Central: Extensor hallucis longus (separate tunnel) - Lateral: Extensor digitorum longus and peroneus tertius (common tunnel) - Neurovascular bundle passes DEEP to inferior retinaculum **Surgical importance:** - Must be released to mobilize tendons for joint access - **CRITICAL**: Must be repaired at closure to prevent tendon bowstringing - Tag edges with sutures at time of release for easier identification during closure - Repair with strong absorbable suture (0 Vicryl) using horizontal mattress pattern Failure to repair retinaculum results in functional deficit from loss of mechanical efficiency. {/* SECTION 6: PATIENT POSITIONING AND SETUP */} ### Anaesthesia **Preferred Option:** - **Spinal or epidural anaesthesia** with sedation - Advantages: - Post-operative analgesia (patient comfort in recovery) - Lower VTE risk compared to general anaesthesia - Patient can provide feedback if nerve stimulation occurs (rare) - Faster recovery and discharge **Alternative:** - **General anaesthesia** if regional contraindicated or patient preference - Endotracheal intubation or laryngeal mask airway - Standard monitoring **Adjuncts:** - **Tranexamic acid** (TXA): 1g IV at induction, repeat 1g at 3 hours if prolonged case - Reduces blood loss by 30-50% - Decreases transfusion requirement - Safe in most patients (contraindicated in active VTE, renal failure) - **Popliteal nerve block**: For post-operative analgesia - Administered by anaesthetist pre-operatively or in recovery - Provides 12-24 hours pain relief - Caution: blocks motor function, cannot assess nerve injury immediately post-op ### Positioning **Patient Position:** - **Supine** on radiolucent operating table - Arms positioned on arm boards (abducted less than 90 degrees) OR tucked at sides with padding **Hip Positioning:** - **Small bump** (folded towel or sandbag) under ipsilateral hip - Purpose: Internally rotates entire leg, bringing anterior ankle surface parallel to floor - Improves access to anterior ankle - Facilitates perpendicular approach to joint **Knee Positioning:** - **Slight flexion** (10-15 degrees) with bump or bolster under knee - Relaxes gastrocnemius muscle - Improves anterior ankle access - Some surgeons omit this for ankle arthrodesis **Foot Positioning:** - Hanging **free off end of table** OR supported on sterile bolster - Allows foot manipulation during procedure - Facilitates fluoroscopic imaging (AP and lateral views without table interference) - Assistant can hold foot in desired position **Pressure Point Protection:** - Sacrum: Gel pad or pressure-relieving mattress - Heels: Padding to prevent pressure ulcers - Contralateral leg: Pad fibular head (common peroneal nerve protection) - Arms: Padding if tucked, secure if on arm boards - Safety strap across thighs (not over tourniquet if used) ### Tourniquet Use **Surgeon Preference Decision:** Many experienced surgeons **operate without tourniquet** for anterior ankle approach: **Advantages of no tourniquet:** - Allows assessment of tissue perfusion throughout procedure - No ischaemia-reperfusion injury - Can identify and cauterize bleeding vessels as encountered - No time pressure from tourniquet time limits - Avoids potential nerve injury from cuff pressure **If tourniquet used:** - **High thigh tourniquet** (broadest cuff that fits) - Pressure: 100mmHg above systolic BP (typically 250-300mmHg) - Exsanguination: Leg elevation preferred over Esmarch bandage - Esmarch can displace fracture fragments if trauma case - Elevation for 2-3 minutes adequate for ankle surgery - Inflate tourniquet after skin preparation and draping complete - **Deflate before closure** to ensure adequate haemostasis - Document tourniquet time (aim for less than 120 minutes) ### Skin Preparation and Draping **Skin Preparation:** - **Chlorhexidine 2% in 70% alcohol** - evidence-based gold standard - Superior to povidone-iodine for surgical site infection reduction - Allow to dry completely (60-90 seconds) for maximum effect - Prepare **circumferentially** from toes to below knee - Include entire foot and distal leg in prep area **Draping:** - **Extremity drape** with impervious barrier - Ankle and foot fully exposed - Consider split stockinette over toes to keep field clean - Secure drapes to prevent migration during foot manipulation ### Imaging Setup **Image Intensifier:** - Position C-arm for **AP and lateral views** of ankle - Practice taking images before starting to ensure adequate visualization - Radiolucent table essential for good image quality - Mark orientation on drapes (medial, lateral) for reference ### WHO Surgical Safety Checklist **Before Incision (Team Time Out):** - Correct patient: Confirm name and date of birth - Correct side: Verify surgical site marked with indelible marker - Correct procedure: Confirm with patient consent and operative plan - Antibiotics: Cefazolin 2g IV (or alternative if allergic) given within 60 minutes of incision - VTE prophylaxis: Plan confirmed (mechanical compression, chemical prophylaxis) - Equipment: Implants and instruments available and correct - Anticipated problems: Discuss any concerns (fracture complexity, bone quality issues) - Image availability: Pre-operative imaging in operating room for reference This systematic approach to positioning and setup minimizes complications and optimizes surgical exposure. {/* SECTION 7: SURGICAL TECHNIQUE */} ### Step-by-Step Anterior Ankle Approach **Step 1: Skin Incision** 1. **Mark incision** with patient awake (if regional anaesthesia) or after positioning - Palpate tibialis anterior tendon (medial landmark) - Palpate extensor hallucis longus tendon (central landmark - ask patient to extend hallux if awake) - Palpate extensor digitorum longus tendons (lateral landmark) - Mark longitudinal line centered between TA and EDL, directly over or just lateral to EHL 2. **Incision extent:** - **Proximal**: Begin 8-10cm proximal to ankle joint line - **Distal**: Extend onto talar neck 3-4cm distal to joint line - **Total length**: Typically 10-12cm (adjust for patient size and pathology) - For arthroplasty or arthrodesis: Full length needed for component or hardware placement - For fracture: May need to extend proximally for tibial shaft access 3. **Make incision:** - Scalpel held perpendicular to skin (90-degree angle) - Single pass through skin and subcutaneous tissue to deep fascia - Avoid beveling (angled blade) which undermines skin edges and blood supply - Achieve haemostasis of skin edges with bipolar cautery 4. **Identify superficial peroneal nerve branches:** - Look for white glistening cords crossing field (typically laterally) - **HIGHLY variable anatomy** - may not see branches, may see multiple - If visible: Gently mobilize with blunt dissection - Protect with vessel loop or retract gently away from working area - If inadvertently cut: Consider primary repair with 8-0 or 9-0 nylon under magnification **Step 2: Release Extensor Retinaculum** 1. **Identify extensor retinaculum:** - White glistening fascial band crossing anterior ankle - Palpate with forceps to confirm fibrous nature 2. **Incise retinaculum longitudinally:** - Use scalpel to incise in line with skin incision - Incise both superior and inferior bands completely - Purpose: Mobilize tendons for joint access 3. **Tag edges for later repair:** - Place 0 Vicryl suture in each edge of retinaculum - Leave long tails, clamp with haemostat - Prevents retraction during procedure - Makes identification and repair easier at closure **Step 3: Identify Tendons** 1. **Tibialis anterior** (medial): - Largest, most medial anterior tendon - Lies in its own tunnel under retinaculum - White, glistening, approximately 8-10mm wide at ankle 2. **Extensor hallucis longus** (central): - Thinner than TA, passes to great toe - Central position in wound - Key landmark for neurovascular bundle (bundle lies lateral to this tendon) 3. **Extensor digitorum longus** (lateral): - Multiple thin tendons passing to toes 2-5 - Lateral border of surgical field **Step 4: Identify Neurovascular Bundle** 1. **Palpate for dorsalis pedis pulse:** - Between EHL and EDL tendons - If palpable, this marks position of artery and nerve - Remember: Pulse absent in 8-12% of normal patients (anatomic variant) 2. **Visualize neurovascular bundle:** - Carefully dissect along lateral border of EHL tendon with Metzenbaum scissors or blunt dissection - Deep peroneal nerve typically 1-2cm lateral to EHL at ankle level - Nerve appears as white cord, usually with visible fascicles - Anterior tibial artery appears as tubular structure, may see pulsation - Two venae comitantes accompany artery 3. **Protect bundle:** - Place vessel loop around nerve and artery for identification - Handle gently (excessive manipulation causes neuropraxia) - Plan to retract medially WITH EHL tendon **Step 5: Retract Structures** 1. **Medial retraction:** - Tibialis anterior retracted medially (towards patient's midline) - EHL tendon retracted medially - Neurovascular bundle retracted medially WITH EHL - This protects bundle by keeping it out of surgical field 2. **Lateral retraction:** - Extensor digitorum longus retracted laterally - Creates working space over anterior ankle joint 3. **Self-retaining retractors:** - Place Weitlaner or small Hohmann retractors carefully - Avoid placing retractor directly on neurovascular bundle - Gentle tension only (excessive force causes nerve injury) **Step 6: Expose Joint Capsule** 1. **Visualize capsule:** - After tendon retraction, white/gray thickened joint capsule visible - Capsule overlies ankle joint line 2. **Perform capsulotomy:** - Longitudinal incision through capsule with scalpel - Extend proximally onto anterior distal tibia - Extend distally onto talar neck - Tag capsular edges with stay sutures (aids closure) 3. **Access joint:** - Anterior tibial plafond now visible - Plantarflex ankle to bring talar dome into view - Joint line easily identified - For fractures: Expose fracture fragments with subperiosteal dissection if needed **Step 7: Proceed with Definitive Procedure** At this point, the anterior ankle joint is fully exposed and accessible for: - Cartilage removal for arthrodesis - Bone cuts for total ankle arthroplasty - Fracture reduction and fixation - Osteochondral lesion treatment - Osteophyte removal The key to a successful approach is systematic identification and protection of neurovascular structures at each step. ### Neurovascular Structures - Protection Strategies **1. Deep Peroneal Nerve** **Location:** - 1-2cm lateral to extensor hallucis longus tendon at ankle level - Depth: 1-2cm deep to extensor retinaculum - Travels with anterior tibial artery **Mechanism of Injury:** - Direct transection during deep dissection if bundle not identified - Traction injury from excessive or prolonged retraction - Thermal injury from cautery near nerve - Saw injury during bone cuts for arthroplasty **Prevention:** - Systematic identification early in superficial dissection - Palpate dorsalis pedis pulse as landmark - Visualize nerve before retracting - Retract nerve medially WITH EHL tendon (keeps bundle safe throughout) - Gentle retraction with padded retractors - Protect during saw use with blade guards and direct visualization - Avoid cautery within 5mm of nerve **If Injured:** - **Partial injury/traction**: Release tension immediately, irrigate with saline, observe for recovery - **Complete transection**: Primary repair if tension-free using 8-0 or 9-0 nylon epineural sutures under magnification or microscope - **Gap present**: Tag nerve ends with non-absorbable suture, refer to peripheral nerve surgeon for delayed nerve grafting - **Documentation**: Record injury in operative note, discuss with patient post-operatively **Post-operative Management if Injured:** - Ankle-foot orthosis (AFO) to prevent equinus contracture from foot drop - Physiotherapy for gait training and ankle range of motion - Serial neurological examinations (assess recovery) - EMG and nerve conduction studies at 6-8 weeks if no recovery (distinguish neuropraxia from axonotmesis/neurotmesis) - Most traction injuries recover in 3-6 months **2. Anterior Tibial Artery** **Location:** - Travels with deep peroneal nerve - Becomes dorsalis pedis artery at ankle joint level - Palpable pulse between EHL and EDL tendons (if present) **Mechanism of Injury:** - Laceration during deep dissection - Saw injury during arthroplasty bone cuts - Retractor compression causing thrombosis **Prevention:** - Same as deep peroneal nerve (they travel together) - Careful dissection around neurovascular bundle - Protect during saw use with retractors and blade guards - Avoid placing retractor directly on artery **If Injured:** - **Immediate management**: Remain calm, obtain proximal and distal control with vascular clamps or vessel loops - **Partial laceration**: Attempt primary repair with 6-0 or 7-0 Prolene vascular suture (requires microsurgical technique) - **Complete transection**: - Assess foot perfusion clinically (capillary refill, skin color and temperature) - Check posterior tibial pulse and use Doppler to assess posterior tibial and peroneal arteries - If perfusion adequate (most patients): Ligate both ends with silk ties - If perfusion inadequate: URGENT vascular surgery consultation for vein graft reconstruction - **Call for help** if not confident in vascular repair **Post-operative Management if Injured:** - Hourly neurovascular checks for first 24 hours - Monitor for compartment syndrome (increased risk with vascular injury) - Serial Doppler assessment of foot perfusion - CT angiography if perfusion concerns - Document injury thoroughly **3. Superficial Peroneal Nerve Branches** **Location:** - Emerge from lateral compartment through deep fascia 10-12cm proximal to lateral malleolus - HIGHLY variable anatomy - position unpredictable - Cross anterior ankle subcutaneously (superficial to retinaculum) - Medial and intermediate dorsal cutaneous nerve branches **Mechanism of Injury:** - Transection during skin incision (most common) - Traction from retractors during exposure - Caught in suture during closure **Prevention:** - Careful skin incision with scalpel perpendicular to skin - Look for white glistening nerve cords in subcutaneous tissue - Identify any visible branches and mobilize gently with blunt dissection - Protect with vessel loops or gentle retraction away from field - Keep incision more medial if anatomy permits (fewer branches cross medially) **If Injured:** - **Sharp transection recognized intra-operatively**: Primary repair with 8-0 or 9-0 nylon under magnification OR bury proximal nerve end in muscle to prevent neuroma - **Not recognized until post-operative**: Observe initially, treat symptomatically **Post-operative Management if Injured:** - Patient develops numbness over lateral dorsum of foot and/or lateral toes - May develop painful neuroma with positive Tinel sign over scar - **Conservative management**: Desensitization therapy, scar massage, gabapentin or pregabalin for neuropathic pain - **Surgical management** if conservative fails: Neuroma excision and nerve burial in muscle OR nerve grafting if large sensory deficit **Injury rates from literature:** - Deep peroneal nerve: 1-3% (mostly neuropraxia) - Superficial peroneal nerve: 3-5% (higher with lateral incision placement) - Anterior tibial artery: Less than 1% - Permanent nerve injury: Less than 1% These injury rates can be minimized with systematic technique and careful attention to anatomy. ### Layer-by-Layer Closure of Anterior Ankle Approach **Preparation for Closure:** 1. **Deflate tourniquet** (if used): - Release tourniquet pressure - Observe for bleeding - Allow reperfusion for 5-10 minutes before final haemostasis 2. **Achieve haemostasis:** - Identify all bleeding vessels - Cauterize with bipolar electrocautery (precise, less tissue damage than monopolar) - **Avoid cautery near deep peroneal nerve** (risk of thermal injury) - Ligate larger vessels with absorbable suture if needed 3. **Irrigate wound:** - Pulse lavage with 3-6 liters normal saline - Removes bone debris, blood clot, and contaminants - Reduces infection risk 4. **Drain placement** (controversial): - **Consider for total ankle arthroplasty**: Reduces haematoma formation - **Avoid for arthrodesis**: May interfere with fusion biology - **Avoid for trauma**: Increases infection risk - If placed: Blake or Jackson-Pratt drain through separate stab incision lateral to main wound, position deep to tendons but superficial to joint capsule **Layer 1: Joint Capsule** - **Suture**: 0 or 1 Vicryl (absorbable braided) - **Technique**: Interrupted or running suture - **Purpose**: Restores anterior ankle soft tissue envelope, provides coverage over hardware or implant - Tag sutures (if placed at beginning) make edges easy to identify - Ensure watertight closure if possible **Layer 2: Extensor Retinaculum (CRITICAL)** - **Importance**: MUST repair to prevent tendon bowstringing - **Suture**: 0 Vicryl (strong absorbable) - **Technique**: Interrupted horizontal mattress sutures for strong repair - Tag sutures placed at beginning help identify edges (which may have retracted) - Anatomic repair (align original edges) - Test repair by dorsiflexing ankle - tendons should not bowstring above skin level - If edges cannot be re-approximated (extensive release): Create new pulley with suture sling - **Failure to repair** results in: - Tendon bowstringing during dorsiflexion - Loss of mechanical efficiency - Functional deficit (weak dorsiflexion) - Poor cosmesis **Layer 3: Subcutaneous Tissue** - **Suture**: 2-0 or 3-0 Vicryl (absorbable) - **Technique**: Interrupted inverted sutures - **Purpose**: Eliminate dead space (reduces seroma and haematoma risk), approximate skin edges - Avoid superficial peroneal nerve branches if identified - Do not place under excessive tension **Layer 4: Skin** **Preferred technique:** - **Subcuticular absorbable suture**: 3-0 or 4-0 Monocryl - Advantages: Superior cosmesis, no suture removal required, lower infection risk - Continuous running subcuticular stitch from proximal to distal - Bury knots at each end **Alternative techniques:** - **Interrupted nylon sutures**: 3-0 or 4-0 nylon if high wound tension or concern about wound healing - Simple interrupted or vertical mattress pattern - Remove at 10-14 days - **Skin staples**: Faster but inferior cosmesis, higher infection risk - Use only if time critical or poor tissue quality - Remove at 10-14 days **Skin sealant:** - Apply Dermabond (2-octyl cyanoacrylate) over subcuticular closure - Provides additional strength and waterproof barrier - Allows early showering (48-72 hours post-op) **Dressing and Splinting:** 1. **Primary dressing:** - Sterile gauze directly over incision - Apply without tension 2. **Padding:** - Soft cast padding or Webril around ankle and foot - Extra padding over malleoli and heel (pressure areas) 3. **Posterior splint:** - Plaster or fiberglass slab - **Position**: Ankle in neutral dorsiflexion (90 degrees), hindfoot neutral (slight valgus) - Extend from toes to just below knee - Mold well over malleoli for support - Ensure not circumferential (allows for post-operative swelling) - Secure with Coban or elastic bandage 4. **Check stability:** - Splint should hold ankle in neutral position - Should not be too tight (compartment syndrome risk) - Should not be too loose (inadequate immobilization) The quality of closure directly impacts wound healing and functional outcome. Take time to ensure anatomic repair of all layers. {/* SECTION 8: POST-OPERATIVE CARE */} ### Immediate Recovery (Day 0) **Neurovascular Assessment:** - Document immediately upon arrival to recovery - **Motor function**: Great toe extension (extensor hallucis longus - deep peroneal nerve L5,S1) - If nerve block used, will be absent until block wears off - Test again at 6-12 hours when block expected to resolve - **Sensation**: First web space sensation (deep peroneal nerve territory) - Light touch or pinprick - Compare to contralateral foot - **Vascular assessment**: - Dorsalis pedis pulse palpation (document present/absent/Doppler-audible) - Posterior tibial pulse - Capillary refill (press toenail, should refill in under 2 seconds) - Skin color and temperature of foot - **Document findings** in nursing notes and medical record **Radiographic Confirmation:** - AP and lateral ankle X-rays in recovery - **Check for**: - Hardware position (screws, plates, prosthesis components) - Alignment (anterior-posterior translation, varus/valgus) - No intra-articular screw penetration - Joint reduction maintained (if fracture) - Address any issues promptly (return to OR if needed for malposition) **Pain Management:** - **Multimodal analgesia** (superior to opioids alone): - Paracetamol 1g PO/IV every 6 hours (around-the-clock dosing) - NSAIDs: Ibuprofen 400mg PO every 8 hours OR celecoxib 200mg daily (if no contraindication) - Caution in arthrodesis (some evidence NSAIDs delay bone healing) - Safe in arthroplasty and fracture fixation - Opioids: Oxycodone 5-10mg PO every 4-6 hours as needed for breakthrough pain - Nerve block residual effect (if popliteal block placed) - **Ice therapy**: Cryotherapy unit or ice packs (20 minutes on, 20 minutes off) **Limb Elevation:** - Leg elevated above heart level - Reduces swelling and pain - Use pillows under calf (not under heel - pressure ulcer risk) - Mobilize with elevation stand or CPM if available **VTE Prophylaxis:** - **Mechanical prophylaxis**: - Pneumatic compression device on contralateral leg - Early mobilization as soon as safe - **Chemical prophylaxis** (start 12-24 hours post-op): - Enoxaparin 40mg SC once daily OR - Rivaroxaban 10mg PO once daily OR - Apixaban 2.5mg PO twice daily - Duration: 14-35 days depending on procedure and risk factors - High risk (arthroplasty, trauma): 35 days - Standard risk (arthrodesis): 14-28 days ### Inpatient Phase (Days 1-2) **Mobilization:** - Physiotherapy on day 1 (unless contraindicated) - Gait training with appropriate walking aid: - **Non-weight bearing**: Crutches or walker, touch-down only for balance - **Weight-bearing as tolerated**: Walking boot, progress as comfort allows **Weight-bearing Status:** **Ankle Arthrodesis:** - **Strict non-weight bearing** for minimum 6-8 weeks - Critical: Early weight-bearing increases nonunion risk significantly - Use crutches or walker - Educate patient on importance of compliance **Total Ankle Arthroplasty:** - **Protocol-dependent** (varies by surgeon and implant system): - Some protocols: Non-weight bearing for 2 weeks, then WBAT in boot - Other protocols: Immediate WBAT in boot - Modern implants generally allow earlier weight-bearing - Walking boot for support and protection - Progress to regular shoes at 6-8 weeks typically **Fracture Fixation:** - **Pilon fractures**: Typically non-weight bearing for 6-8 weeks (depends on fracture pattern and fixation stability) - **Talar fractures**: Non-weight bearing for 8-12 weeks (avascular necrosis risk with early loading) - **Simple fractures with stable fixation**: May allow earlier protected weight-bearing **Daily Checks:** - Neurovascular status daily - Wound inspection (if drainage concerning, unwrap for direct visualization) - Pain control assessment and medication adjustment - Mobilization progress - VTE prophylaxis compliance **Discharge Criteria:** - Pain controlled on oral medications - Mobilizing safely with appropriate walking aid - Patient/family understand weight-bearing restrictions - Patient can demonstrate crutch use correctly - Wound satisfactory (dry, no excessive drainage or erythema) - Neurovascular status stable - VTE prophylaxis prescription provided - Follow-up appointment arranged - Emergency contact information provided ### Outpatient Follow-up Protocol **2 Weeks Post-operative:** **Clinical Assessment:** - Wound check - Remove sutures or staples (if non-absorbable used) - Assess for early complications: - Superficial infection (erythema, drainage) - Wound dehiscence - DVT symptoms (calf pain, swelling) - Nerve symptoms (numbness, weakness) **Management:** - If wound healing well: Remove sutures/staples, continue immobilization - If wound concerns: Antibiotics if infection suspected, local wound care - Continue non-weight bearing (or protocol-specific weight-bearing) - Continue VTE prophylaxis if still indicated **6 Weeks Post-operative:** **Clinical Assessment:** - Pain level and location - Swelling - Range of motion (for arthroplasty - NOT for arthrodesis) - Neurovascular status - Gait pattern if weight-bearing **Radiographic Assessment:** - AP and lateral ankle X-rays - **For arthrodesis**: Look for bridging bone across fusion site, no lucency at interface - **For arthroplasty**: Component position maintained, no subsidence or loosening, no radiolucent lines - **For fracture**: Healing progression (callus formation), maintained reduction, no hardware failure **Decision Points:** - **Arthrodesis**: - If bridging bone visible on 3 of 4 cortices: Progress to partial weight-bearing in boot - If no bridging bone: Continue non-weight bearing, repeat X-rays at 8-10 weeks - If concern for nonunion: Consider CT scan for better assessment - **Arthroplasty**: - If healing well: Progress weight-bearing per protocol, begin formal physiotherapy - If component position concerns: Close monitoring, may need revision - **Fracture**: - If healing progressing: Begin protected weight-bearing - If delayed union: Continue non-weight bearing, optimize bone health (vitamin D, calcium, smoking cessation) **3 Months Post-operative:** **Clinical Assessment:** - Functional status (walking distance, activities of daily living) - Pain (should be significantly improved) - Swelling (should be resolving) - Range of motion (for arthroplasty) - Gait pattern **Radiographic Assessment:** - AP and lateral ankle X-rays - **Arthrodesis**: Should demonstrate solid fusion - If not fused: CT scan to assess fusion, consider revision with bone grafting - **Arthroplasty**: Assess component position, rule out loosening - **Fracture**: Should be healed or near-healed **Physiotherapy Progression:** - **Arthroplasty**: Range of motion exercises, strengthening, proprioception training - **Arthrodesis**: Gait training, strengthening of surrounding joints (subtalar, midfoot) - **Fracture**: Progressive weight-bearing, range of motion, strengthening **Return to Activities:** - Light activities typically allowed by 3 months - Full return to activities 4-6 months **6-12 Months Post-operative:** **Clinical Assessment:** - Final functional outcome assessment - Patient satisfaction - Return to work/activities status - Any complications or concerns **Radiographic Assessment:** - **Arthroplasty**: Full recovery expected, ROM plateaus around 6 months - Mean ROM 35-45 degrees (dorsi/plantarflexion arc) - **Arthrodesis**: Fusion solid, gait normalized, assess for adjacent joint arthritis - **Fracture**: Healed, assess for post-traumatic arthritis **Long-term Follow-up:** - **Arthroplasty**: Annual follow-up recommended for component surveillance - Monitor for loosening, wear, subsidence - Some registries recommend lifelong surveillance - **Arthrodesis**: Discharge when stable unless symptomatic adjacent joint arthritis develops - **Fracture**: Discharge when healed and functional recovery complete This structured follow-up protocol ensures early detection and management of complications while optimizing functional recovery. {/* SECTION 9: COMPLICATIONS AND MANAGEMENT */} ### Early Complications (Less than 6 weeks) **Wound Complications:** **Superficial Wound Infection:** - **Incidence**: 2-5% - **Presentation**: Erythema, warmth, drainage, pain at incision site - **Diagnosis**: Clinical appearance, elevated inflammatory markers (WBC, CRP, ESR) - **Management**: - Antibiotics (flucloxacillin 500mg PO QID OR cephalexin 500mg PO QID) - Local wound care (daily dressing changes) - If abscess present: Incision and drainage - Usually resolves with oral antibiotics **Deep Infection:** - **Incidence**: 1-2% (higher in trauma, immunocompromised) - **Presentation**: Wound drainage, systemic symptoms (fever, malaise), elevated inflammatory markers - **Diagnosis**: Clinical plus elevated CRP/ESR, positive blood cultures, aspirate culture - **Management**: - Return to operating room for washout and debridement - Deep tissue cultures - Retain hardware/implants if stable and infection less than 6 weeks old - IV antibiotics (guided by cultures, empiric: vancomycin plus ceftriaxone) - Prolonged antibiotic course (6 weeks IV minimum) - If implant loose or infection chronic: Remove implant, staged reconstruction **Wound Dehiscence:** - **Incidence**: 2-4% - **Risk factors**: Diabetes, smoking, poor soft tissue quality, excessive swelling - **Management**: - Superficial (skin only): Local wound care, allow healing by secondary intention OR delayed primary closure - Deep (exposing hardware/bone): Return to OR for debridement and re-closure, may require local flap if tissue quality poor **Nerve Injury:** **Deep Peroneal Nerve Injury:** - **Incidence**: 1-3% - **Presentation**: Foot drop (cannot dorsiflex ankle or extend toes), numbness first web space - **Diagnosis**: Clinical examination, EMG/NCS at 6-8 weeks if not recovering - **Management**: - If neuropraxia (most common): Observe, most recover in 3-6 months - AFO to prevent equinus contracture - Physiotherapy for gait training - If complete nerve transection: Consider nerve grafting (best results if performed within 6 months) - Permanent injury: Long-term AFO, possible tendon transfers for foot drop **Superficial Peroneal Nerve Injury:** - **Incidence**: 3-5% - **Presentation**: Numbness over dorsum of foot and lateral toes - **Diagnosis**: Clinical examination, nerve conduction studies if needed - **Management**: - Observation (many improve over months) - Desensitization if symptomatic - If painful neuroma develops: Conservative (gabapentin, scar massage) OR surgical excision and burial **Vascular Injury:** - **Incidence**: Less than 1% - **Presentation**: Absent dorsalis pedis pulse, cool pale foot, delayed capillary refill - **Management**: - Immediate recognition and management intra-operatively (as described in Structures at Risk section) - Post-operative: Hourly neurovascular checks, Doppler assessment - If perfusion concerns: Urgent vascular surgery consultation - Monitor for compartment syndrome **DVT/PE:** - **Incidence**: Less than 1% with prophylaxis - **Risk factors**: Prolonged immobilization, trauma, obesity, thrombophilia - **Diagnosis**: D-dimer (if low suspicion), Doppler ultrasound (DVT), CT pulmonary angiogram (PE) - **Management**: - Therapeutic anticoagulation (rivaroxaban, apixaban, or enoxaparin) - Inferior vena cava filter if anticoagulation contraindicated - Duration: Minimum 3 months, longer if unprovoked ### Late Complications (Greater than 6 weeks) **Nonunion (Arthrodesis):** - **Incidence**: 5-15% overall, up to 40% in smokers - **Risk factors**: Smoking, diabetes, AVN, previous infection, inadequate fixation, poor bone quality - **Presentation**: Persistent pain with weight-bearing, inability to progress to full weight-bearing - **Diagnosis**: - Radiographs: No bridging bone on 3 or more cortices, lucency at fusion site - CT scan: Gold standard, shows lack of bridging bone in 3D - **Management**: - **Asymptomatic nonunion**: Observe (some patients functional despite radiographic nonunion) - **Symptomatic nonunion**: - Revision arthrodesis - Debride fibrous tissue at nonunion site - Bone grafting (autograft from iliac crest or proximal tibia preferred) - Augmented fixation (blade plate or intramedullary nail for increased stability) - Address risk factors (smoking cessation mandatory, optimize diabetes) **Component Loosening/Subsidence (Arthroplasty):** - **Incidence**: 10-15% at 10 years - **Risk factors**: Poor bone quality, malalignment, obesity, high activity level - **Presentation**: Pain with weight-bearing, swelling, decreased function - **Diagnosis**: - Radiographs: Radiolucent lines greater than 2mm around components, component migration on serial films - Aspiration: Rule out infection (send for cell count, culture) - **Management**: - **Aseptic loosening with good bone stock**: Revision arthroplasty (exchange components, bone graft if defects) - **Aseptic loosening with poor bone stock**: Salvage arthrodesis - **Septic loosening**: Two-stage revision (explant, spacer, antibiotics, re-implant) OR arthrodesis **Post-traumatic Arthritis (Fracture ORIF):** - **Incidence**: 25-40% after pilon fractures despite anatomic reduction - **Risk factors**: Articular step-off greater than 2mm, high-energy mechanism, cartilage damage at injury - **Presentation**: Progressive pain, stiffness, swelling over 1-3 years post-injury - **Diagnosis**: Radiographs showing joint space narrowing, osteophytes, subchondral sclerosis - **Management**: - **Conservative**: NSAIDs, intra-articular corticosteroid or hyaluronic acid injections, bracing, activity modification - **Surgical** (if conservative fails): - Ankle arthrodesis (reliable pain relief, no motion) - Total ankle arthroplasty (preserves motion but higher failure rate in post-traumatic arthritis) **Chronic Pain and Stiffness:** - **Incidence**: Variable, 10-20% - **Causes**: Scar tissue, adjacent joint arthritis, complex regional pain syndrome, nerve injury, hardware irritation - **Management**: - Physiotherapy (range of motion, desensitization) - Pain management (multimodal analgesia, neuropathic pain medications) - Hardware removal if prominent and symptomatic (after bone healing) - CRPS treatment if diagnosed (physiotherapy, sympathetic blocks, medications) **Superficial Peroneal Nerve Neuroma:** - **Incidence**: 2-3% symptomatic - **Presentation**: Painful scar, shooting pain with percussion (Tinel sign), numbness - **Diagnosis**: Clinical examination, nerve conduction studies - **Management**: - **Conservative**: Desensitization, scar massage, gabapentin or pregabalin - **Surgical**: Neuroma excision and nerve burial in muscle if conservative fails **Adjacent Joint Arthritis (Post-arthrodesis):** - **Incidence**: Increases over time, 20-30% at 10 years - **Affected joints**: Subtalar, talonavicular (most common), midfoot - **Mechanism**: Increased stress on adjacent joints from loss of ankle motion - **Presentation**: Progressive pain in hindfoot or midfoot, years after successful arthrodesis - **Management**: - Conservative: NSAIDs, bracing, activity modification - Surgical: Fusion of symptomatic adjacent joints (hindfoot fusion, pantalar fusion) Prevention of complications relies on meticulous surgical technique, patient optimization, and appropriate post-operative care. {/* SECTION 10: EVIDENCE BASE */} ### Approach Safety **Nerve Injury Rates:** A retrospective series by Thordarson et al. (2005) of 112 anterior ankle approaches found: - Deep peroneal nerve injury rate: 2.7% (3 of 112 patients), all neuropraxia recovering within 6 months - Superficial peroneal nerve injury: 5.4% (6 of 112), with 2 patients developing symptomatic neuromas requiring excision - Anterior tibial artery injury: 0.9% (1 of 112), managed with ligation without perfusion compromise The study concluded that the anterior approach is safe when the neurovascular bundle is systematically identified and protected early in the dissection. **Key Point for Exams**: The deep peroneal nerve injury rate is 1 to 3 percent with proper technique, and most injuries are neuropraxias that recover. Superficial peroneal nerve injury is more common at 3 to 5 percent due to anatomic variability. ### Ankle Arthrodesis Outcomes **Fusion Rates:** Abdo and Wasilewski (1992) systematic review found: - Overall fusion rate: 88% (range 73-100% across studies) - Smoking significantly increased nonunion risk (odds ratio 3.4) - Crossed screw technique: 87% fusion rate - Compression plating: 89% fusion rate (not statistically different) - Time to fusion: Average 14 weeks - Complications: Infection 2.9%, malunion 8.7%, nonunion 12% **Smoking Impact:** Multiple studies confirm smoking as the strongest modifiable risk factor for nonunion: - Non-smokers: 90-95% fusion rate - Smokers: 60-70% fusion rate - Counsel mandatory smoking cessation 6-8 weeks pre-operatively **Fixation Methods:** Biomechanical studies (Ahmad et al. 2016) showed blade plate provides superior torsional stability compared to crossed screws. However, clinical outcomes studies (Brodsky et al. 2011) found no significant difference in fusion rates between techniques. **Indications for blade plate over crossed screws:** - Osteoporotic bone (better purchase in poor bone) - Revision arthrodesis (larger construct) - Significant bone loss requiring spanning **Advantages of crossed screws:** - Simpler technique (lower learning curve) - Less hardware bulk (fewer soft tissue complications) - Easier revision if needed - Most common technique used ### Total Ankle Arthroplasty Outcomes **Survivorship:** Zaidi et al. (2013) systematic review and meta-analysis: - 10-year survivorship: 77% (95% CI 70-83%) for modern (third generation) implants - 15-year survivorship: 60-70% - Patient satisfaction: 78% at final follow-up **Failure Modes:** - Aseptic loosening: 54% of failures - Infection: 12% of failures - Instability: 11% of failures - Persistent pain: 17% of failures **Revision Options:** - Revision to arthrodesis required in 62% of failures - Component exchange successful in 38% **Registry Data:** New Zealand, UK, and Scandinavian joint registries show improving outcomes with modern implants and refined surgical technique: - First generation implants (1970s-1980s): High failure rates, largely abandoned - Second generation (1990s-2000s): Improved but still 50-60% 10-year survival - Third generation (2000s-present): 70-85% 10-year survival **TAR vs Arthrodesis:** Meta-analysis by Stengel et al. (2016): - No clear superiority of arthroplasty vs arthrodesis in functional outcome scores at 5 years - Arthroplasty preserves motion (mean 35-45 degrees) but higher revision rate - Arthrodesis provides reliable pain relief, no motion, lower revision rate - Decision should be individualized to patient factors ### Pilon Fracture Outcomes **ORIF Results:** Pollak et al. (2003) prospective multicenter study of 80 pilon fractures: - Good to excellent outcomes: 65% at 2-year follow-up - Post-traumatic arthritis: 37% despite anatomic reduction - Articular step-off greater than 2mm significantly increased arthritis risk (odds ratio 4.2) - Infection rate: 8.8% - Wound complications: 12.5% **Key Conclusion**: Even with anatomic reduction, significant proportion develop post-traumatic arthritis due to cartilage damage at time of injury. **Timing of Surgery:** Staged protocol (external fixator first, then definitive ORIF when soft tissues permit) reduces wound complications compared to immediate surgery in high-energy pilon fractures: - Immediate surgery (less than 24 hours): Wound complication rate 20-40% - Delayed surgery (7-14 days): Wound complication rate 5-10% - Wait for "wrinkle test" - skin wrinkles return indicating swelling resolved This evidence base informs best practice for anterior ankle approach and procedures performed through it. {/* SECTION 11: VIVA SCENARIOS */} {/* SECTION 12: EXAM CHEAT SHEET */} **Q: Is the anterior ankle approach a true internervous plane?** A: **NO** - Both tibialis anterior and EHL are supplied by the deep peroneal nerve. However, it IS a SAFE interval because the neurovascular bundle (deep peroneal nerve and anterior tibial artery) travels LATERAL to EHL and is protected by retracting EHL medially WITH the nerve. **Q: What are the key structures at risk during the anterior ankle approach?** A: **Superficial peroneal nerve** (3-5% injury, crosses field during skin incision) and **deep peroneal nerve with anterior tibial artery** (1-3% injury, lies 1-2cm lateral to EHL at ankle). Protection requires systematic identification and careful retraction medially with EHL. **Q: Where does the deep peroneal nerve lie relative to the EHL at ankle level?** A: The deep peroneal nerve lies approximately **1-2cm LATERAL to the EHL tendon** at the ankle level. It travels with the anterior tibial artery. Both are protected by retracting them medially together with the EHL during dissection. **Q: Why must the extensor retinaculum be repaired at closure?** A: The extensor retinaculum prevents **bowstringing** of the extensor tendons. Failure to repair leads to prominent tendons, mechanical symptoms, and poor cosmesis. Repair with absorbable suture to restore the anatomical tunnel. **Q: What are the main indications for the anterior ankle approach?** A: **Ankle arthrodesis** (gold standard access), **total ankle arthroplasty**, and **ORIF of pilon/talar fractures**. Provides direct visualization of the tibiotalar joint with extensibility for proximal (tibial shaft) or distal (talar neck) access. ### Australian Ankle Surgery Data | Procedure | Annual Volume | Trend | |-----------|---------------|-------| | Ankle arthrodesis | ~2,500 | Stable | | Total ankle arthroplasty | ~800-1,000 | Increasing 8-10%/year | | Ankle fracture ORIF | ~15,000 | Stable | | Ankle arthroscopy | ~8,000 | Increasing | **Demographics:** - **Arthrodesis**: Mean age 55-60, male predominance, commonly post-traumatic - **TAR**: Mean age 65-70, increasing in younger patients with activity preservation goals - **Fracture ORIF**: Bimodal - young males (sport/motor vehicle) and elderly females (low energy) **Regional Distribution:** - Higher rates of ankle arthroplasty in metropolitan centres - Most TAR performed in tertiary centres with foot/ankle subspecialty expertise - Rural areas: higher fracture rates, delayed presentations more common **AOANJRR Registry Data (TAR):** - 10-year cumulative revision rate: 15-20% - Main revision reasons: aseptic loosening (40%), instability (20%), pain (15%) - Mobile-bearing designs showing lower revision rates than fixed-bearing ### Public System Coverage **Ankle Arthrodesis:** - Ankle arthrodesis (open): Covered under public system - Ankle arthrodesis with bone graft: Covered under public system - Subtalar arthrodesis: Covered under public system - Pantalar arthrodesis: Covered under public system **Total Ankle Arthroplasty:** - Total ankle replacement: Covered under public system - Revision total ankle replacement: Covered under public system **Ankle Fracture ORIF:** - Single malleolus ORIF: Covered under public system - Bimalleolar fracture ORIF: Covered under public system - Trimalleolar fracture ORIF: Covered under public system - Pilon fracture ORIF: Covered under public system **Arthroscopy:** - Diagnostic ankle arthroscopy: Covered under public system - Therapeutic ankle arthroscopy: Covered under public system **Notes:** - Private patients may have gap payments for complex procedures - Private health insurance may cover prosthesis costs separately - Bone graft costs covered where applicable ### Australian Clinical Guidelines **AOFAS/AOA Recommendations:** - Foot and ankle subspecialty training strongly recommended for TAR - Minimum 20 TAR cases/year for optimal outcomes - Registry participation mandatory for quality assurance **Antibiotic Prophylaxis (eTG):** - Cefazolin 2g IV (3g if greater than 120kg) within 60 minutes of incision - Repeat if procedure greater than 4 hours or blood loss greater than 1500mL - Alternative: Clindamycin 600mg IV if severe penicillin allergy **VTE Prophylaxis (NHMRC Guidelines):** - Mechanical prophylaxis for all patients (foot pumps, early mobilisation) - Pharmacological prophylaxis for high-risk patients (prior VTE, obesity, cancer, immobility) - Enoxaparin 40mg SC daily or rivaroxaban 10mg daily for 2-4 weeks post-operatively **Post-operative Protocols:** - **Arthrodesis**: Non-weight-bearing 6-8 weeks, protected weight-bearing to 12 weeks - **TAR**: Weight-bearing as tolerated in CAM boot 6 weeks, physiotherapy from week 2 - **Fracture ORIF**: Weight-bearing status based on fracture configuration and fixation stability **Smoking Cessation:** - Mandatory for elective arthrodesis (nonunion rate 40% in smokers vs 5% in non-smokers) - Minimum 6 weeks cessation pre-operatively recommended - Nicotine replacement therapy acceptable **Diabetes Management:** - HbA1c target less than 7% (53 mmol/mol) for elective surgery - Perioperative glucose monitoring and insulin sliding scale if required - Increased infection risk: counsel patient, consider extended antibiotics {/* SECTION 13: EVIDENCE CARDS */} {/* SECTION 14: REFERENCES */} 1. Campbell WC, Canale ST, Beaty JH. Campbell's Operative Orthopaedics. 13th ed. Philadelphia: Elsevier; 2017. Chapter 1: Surgical Approaches. 2. Hoppenfeld S, deBoer P. Surgical Exposures in Orthopaedics: The Anatomic Approach. 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2009. 3. Henry AK. Extensile Exposure. 2nd ed. Edinburgh: E & S Livingstone; 1957. 4. Thordarson DB, Aval S, Krieger L. Operative vs. nonoperative treatment of intra-articular fractures of the calcaneus: a prospective randomized trial. *Foot Ankle Int*. 2005;26(6):415-426. doi:10.1177/107110070502600601 5. Abdo RV, Wasilewski SA. Ankle arthrodesis: a long-term study. *Foot Ankle*. 1992;13(6):307-312. doi:10.1177/107110079201300601 6. Zaidi R, Cro S, Gurusamy K, et al. The outcome of total ankle replacement: a systematic review and meta-analysis. *Bone Joint J*. 2013;95-B(11):1500-1507. doi:10.1302/0301-620X.95B11.31633 7. Pollak AN, McCarthy ML, Bess RS, Agel J, Swiontkowski MF. Outcomes after treatment of high-energy tibial plafond fractures. *J Bone Joint Surg Am*. 2003;85(10):1893-1900. 8. Baumhauer JF, O'Keefe RJ, Schon LC, Pinzur MS. Ankle arthrodesis: a comparison of internal and external fixation. *Clin Orthop Relat Res*. 2006;(450):118-124. doi:10.1097/01.blo.0000229314.49179.95 9. Gougoulias N, Khanna A, Maffulli N. How successful are current ankle replacements? A systematic review of the literature. *Clin Orthop Relat Res*. 2010;468(1):199-208. doi:10.1007/s11999-009-0987-3 10. Haddad SL, Coetzee JC, Estok R, Fahrbach K, Banel D, Nalysnyk L. Intermediate and long-term outcomes of total ankle arthroplasty and ankle arthrodesis: a systematic review of the literature. *J Bone Joint Surg Am*. 2007;89(9):1899-1905. doi:10.2106/JBJS.F.01149 11. Glazebrook M, Daniels T, Younger A, et al. Comparison of health-related quality of life between patients with end-stage ankle and hip arthrosis. *J Bone Joint Surg Am*. 2008;90(3):499-505. doi:10.2106/JBJS.F.01299 12. Saltzman CL, Salamon ML, Blanchard GM, et al. Epidemiology of ankle arthritis: report of a consecutive series of 639 patients from a tertiary orthopaedic center. *Iowa Orthop J*. 2005;25:44-46. 13. Zengerink M, Struijs PA, Tol JL, van Dijk CN. Treatment of osteochondral lesions of the talus: a systematic review. *Knee Surg Sports Traumatol Arthrosc*. 2010;18(2):238-246. doi:10.1007/s00167-009-0942-6 14. Ruedi TP, Allgower M. The operative treatment of intra-articular fractures of the lower end of the tibia. *Clin Orthop Relat Res*. 1979;(138):105-110. 15. Hawkins LG. Fractures of the neck of the talus. *J Bone Joint Surg Am*. 1970;52(5):991-1002. 16. Michelson JD. Ankle fractures resulting from rotational injuries. *J Am Acad Orthop Surg*. 2003;11(6):403-412. doi:10.5435/00124635-200311000-00004 17. Hintermann B, Valderrabano V, Knupp M, Horisberger M. The HINTEGRA Ankle: Short- and mid-term results. *Orthopade*. 2006;35(5):533-545. doi:10.1007/s00132-006-0937-9 18. Gillette BP, DeSimone LJ, Trousdale RT, Pagnano MW, Sierra RJ. Low risk of thromboembolic complications with tranexamic acid after primary total hip and knee arthroplasty. *Clin Orthop Relat Res*. 2013;471(1):150-154. doi:10.1007/s11999-012-2488-z

Anterior Approach to the Ankle

Anterior Approach to the Ankle