Medial Approach to Ankle (Medial Malleolus)

Why the Medial Approach Matters

The medial malleolus is involved in 60% of all ankle fractures (isolated 20%, bimalleolar 30%, trimalleolar 10%) - making the medial approach one of the most commonly performed lower extremity surgical approaches. Its importance extends beyond fracture fixation to deltoid ligament pathology, which is increasingly recognized as a critical stabilizer of the ankle joint.

Three Reasons This Approach Is Essential:

1. Medial Malleolus Biomechanics: The medial malleolus provides 30-40% of ankle joint stability (lateral malleolus 40%, syndesmosis 20%) - anatomic reduction is CRITICAL for ankle congruity and prevention of post-traumatic arthritis
2. Deltoid Ligament Complex: Deep deltoid ligament (talotibial component) is the PRIMARY restraint to lateral talar shift - injury creates "bimalleolar equivalent" requiring surgical treatment
3. Subcutaneous Location: Medial malleolus is subcutaneous with minimal soft tissue coverage - direct access BUT meaningful hardware-prominence risk (symptomatic removal in roughly 10-30% of patients)

Historical Evolution:

• 1950s-1970s: Lag screw fixation standard (perpendicular to fracture line - biomechanically optimal)
• 1980s-1990s: Tension band wiring introduced (AO principles - converts distraction to compression)
• 2000s-Present: Cannulated screw systems dominant (percutaneous vs open debate - open allows direct visualization, ensures anatomic reduction)

Global Burden: Ankle fractures are among the most common lower-limb fractures requiring operative fixation worldwide, with a population incidence of roughly 100-180 per 100,000 per year and a bimodal distribution (young men from high-energy injury, older women from low-energy falls). The medial malleolus is involved in the majority of operatively treated patterns, so the medial approach is a fundamental, examinable skill across every major training curriculum (FRCS Tr & Orth, FRACS, EBOT/FEBOT, ABOS, DNB/MS).

Fracture Indications (Primary Use)

Medial Malleolar Fractures:

1. Isolated Medial Malleolus Fracture (20% of ankle fractures)

• Displaced (>2mm displacement OR >2mm articular step)
• Unstable (medial clear space >4mm on mortise view - indicates concomitant deltoid/syndesmosis injury)
• Large fragment (>30% of tibial plafond articular surface on AP X-ray)

Lauge-Hansen Classification Context:

• Supination-External Rotation (SER) IV: Medial malleolus transverse fracture (most common pattern - 60%)
• Supination-Adduction (SAD) I: Medial malleolus vertical fracture (requires antiglide plate fixation - screws alone inadequate)
• Pronation-External Rotation (PER) IV: Medial malleolus transverse fracture (high-energy - associated syndesmotic injury)
• Pronation-Abduction (PAB) II: Medial malleolus oblique/comminuted fracture (deltoid avulsion common)

2. Bimalleolar Fractures (30% of ankle fractures)

• Medial + lateral malleolus fractures
• Lateral malleolus fixed first (restores fibular length), then medial (restores mortise congruity)
• Both sides must be anatomically reduced (stepwise fixation - lateral → medial → syndesmosis if needed)

3. Trimalleolar Fractures (10% of ankle fractures)

• Medial + lateral + posterior malleolus fractures
• Fixation sequence: Posterior → lateral → medial (restore posterior column first)
• Medial approach allows assessment of medial plafond (ensure no intra-articular fragments)

4. Bimalleolar Equivalent

• Lateral malleolus fracture + deep deltoid ligament rupture (NO medial malleolar fracture)
• Clinical: Medial ankle tenderness, medial ecchymosis, widened medial clear space >4mm
• Treatment: Lateral malleolus ORIF + deltoid ligament repair via medial approach

Non-Fracture Indications

Deltoid Ligament Pathology:

Acute Deltoid Rupture:

• Bimalleolar equivalent (lateral malleolar fracture + deltoid rupture - no medial malleolar fracture)
• Pure deltoid avulsion from talus (high-energy - eversion injury)
• Technique: Suture anchors into talus, repair deep deltoid (superficial can be left)

Chronic Deltoid Insufficiency:

• Flatfoot deformity with deltoid incompetence (stage IV posterior tibial tendon dysfunction)
• Medial ankle instability (chronic lateral talar shift on stress X-rays)
• Reconstruction: Deltoid augmentation with autograft (peroneus longus, Achilles tendon allograft)

Medial Ankle Joint Pathology:

Osteochondral Lesions (OCL):

• Medial talar dome OCL (medial lesions 60%, lateral 40% - medial deeper and more symptomatic)
• Access: Medial malleolar osteotomy (cut malleolus, flip down, access talus, repair malleolus)

Medial Ankle Impingement:

• Anteromedial impingement (bone spurs on medial malleolus and medial talus)
• Debridement via medial approach (remove spurs, synovectomy)

Tibialis Posterior Tendon Pathology:

• Tenosynovectomy (stage I posterior tibial tendon dysfunction - synovitis without rupture)
• Tendon debridement (stage IIA - partial tear)

Contraindications

Absolute:

• Active Infection: Soft tissue infection, osteomyelitis (stage treatment - antibiotics first, delayed ORIF)

Relative:

• Severe Open Fracture: Gustilo IIIB/IIIC with medial soft tissue loss (temporize with external fixation, delayed ORIF)
• Peripheral Vascular Disease: Critical limb ischaemia (ABI under 0.5 - wound healing concern, consider vascular consult)
• Neuropathic Arthropathy (Charcot): Relative - fracture may not heal, high complication rate
• Non-displaced Fracture in Elderly: Some advocate conservative management (CAM boot, NWB 6 weeks) - controversial

Special Considerations:

• Diabetes: Higher infection risk (5-10% vs 2-5% non-diabetic), optimize glucose control preop (HbA1c <7%)
• Smoking: Triples non-union risk (counsel cessation 6 weeks preop, restart 12 weeks postop)

Clinical Assessment

Mechanism of Injury (Predicts Fracture Pattern):

• Inversion injury: Lateral malleolus fracture + medial malleolus vertical fracture (SAD pattern)
• Eversion injury: Medial malleolus transverse fracture ± lateral malleolus (SER, PER patterns)
• Axial load + rotation: Pilon-type fracture (high-energy - articular comminution, medial plafond involvement)

Physical Examination:

Inspection:

• Deformity: Varus (SAD), valgus (PER), gross dislocation (emergent reduction required)
• Swelling: Massive swelling delays surgery (fracture blisters develop 12-36 hours post-injury - wait until wrinkle sign)
• Skin integrity: Open wounds, blisters, abrasions (infection risk)
• Fracture blisters: Clear fluid (epithelial separation - safe to operate through), hemorrhagic (dermis involved - avoid incision through blister)

Palpation:

• Medial malleolus tenderness: Fracture vs deltoid ligament avulsion
• Lateral malleolus tenderness: Associated lateral malleolus fracture (bimalleolar)
• Proximal fibula tenderness: Maisonneuve fracture (proximal fibula fracture + syndesmotic injury + medial malleolar fracture OR deltoid rupture)
• Syndesmosis: Squeeze test, external rotation test (pain at syndesmosis suggests injury)

Range of Motion:

• Defer if grossly displaced (fracture unstable - avoid further displacement)
• If minimally displaced: Assess dorsiflexion/plantarflexion (painful but possible)

Neurovascular Examination (MANDATORY):

• Dorsalis pedis pulse: Palpate (if absent - emergent reduction, reassess, if still absent = vascular surgery consult)
• Posterior tibial pulse: Posterior to medial malleolus (usually intact unless posterior tibial artery injury)
• Deep peroneal nerve: EHL function (great toe dorsiflexion), sensation first web space
• Superficial peroneal nerve: Sensation dorsum of foot (lateral 4 toes)
• Tibial nerve: FHL function (great toe plantarflexion), sensation plantar foot
• Saphenous nerve: Sensation medial foot/ankle (purely sensory - injury common from approach)

Imaging Essentials

Radiographs (AP, Lateral, Mortise - MANDATORY):

AP Ankle:

• Medial malleolus fracture line (transverse, vertical, oblique, comminuted)
• Talocrural angle (medial malleolus articular surface to horizontal - normal 80-85°)
• Medial clear space (distance between medial malleolus and medial talus - normal <4mm)

Lateral Ankle:

• Posterior malleolus fracture (25% of ankle fractures - assess size)
• Talar shift (anterior or posterior displacement)

Mortise View (Most Important for Medial Malleolus):

• Medial clear space: Normal <4mm (if >4mm = deltoid ligament injury or fracture displacement)
• Superior clear space: Normal 2-4mm (equal to medial/lateral clear space - asymmetry suggests talar shift)
• Talocrural angle: Assess for varus/valgus deformity
• Fracture displacement: Measure displacement (>2mm = surgical indication), articular step (>2mm = surgical)

Stress Views (If Bimalleolar Equivalent Suspected):

• Gravity stress: Lateral X-ray with ankle hanging off table (gravity stresses deltoid)
• External rotation stress: Mortise view with external rotation force (widens medial clear space if deltoid ruptured)
• Indication: Isolated lateral malleolus fracture with medial tenderness but NO visible medial malleolar fracture (assess for occult deltoid rupture)

CT Scan (Selected Cases):

• Intra-articular extension: Assess articular surface (step-off, impaction, comminution)
• Pilon fractures: Medial plafond involvement (coronal CT shows medial column fracture pattern)
• Occult fractures: Medial malleolus stress fracture (negative X-ray, positive bone scan/MRI)

MRI (Non-Fracture Pathology):

• Deltoid ligament injury: Assess deep vs superficial deltoid (MRI 90% sensitive for deep deltoid tear)
• Osteochondral lesions: Talar dome OCL (size, location, cartilage integrity)
• Tendon pathology: Posterior tibial tendon (stage PTTD), flexor tendons

Surgical Planning Decision Points

Fixation Strategy - Fracture Pattern Determines Method:

The Evidence:

• Biomechanical data (Pollard et al, J Foot Ankle Surg 2010) show construct strength depends on cortical purchase: two 3.5mm bicortical screws resisted pullout far better than 4.0mm partially threaded unicortical cancellous screws (327.6N vs 116.2N) - important in osteoporotic bone
• Union rates are high (over 95%) across screw, tension-band and plate techniques; the practical differentiator is symptomatic hardware prominence, which is highest for the most superficial constructs (plates/tension-band wires) and lower for buried screws

Key Decision Point:

• Transverse/short oblique (70% of medial malleolar fractures): Use 2× cannulated lag screws (4.0mm partially threaded)
• Vertical fracture (SAD pattern - 15%): Use antiglide plate (screws alone will fail - shear forces)
• Comminuted (15%): Use tension band OR plate (screws cannot compress multiple fragments)

Essential Instrumentation

Standard Orthopaedic Set:

• Scalpel (15 blade)
• Self-retaining retractor (small Weitlaner)
• Army-Navy retractors
• Freer elevator (periosteal elevation)
• Electrocautery (bipolar preferred)

Fracture-Specific Instruments:

• Reduction Forceps: Pointed reduction clamps (reduce fracture, maintain reduction during fixation)
• Weber Clamp: Large reduction clamp (compresses medial malleolus to tibia - holds reduction)
• K-wires: 1.6mm or 2.0mm for provisional fixation
• Fluoroscopy: C-arm (MANDATORY - AP, lateral, mortise views during case)

Cannulated Screw System:

• Guidewires: 1.6mm (for 4.0mm cannulated screws)
• Cannulated Drill: 3.2mm (over guidewire - pilot hole for 4.0mm screw)
• Depth Gauge: Measure screw length over guidewire
• Cannulated Screws: 4.0mm partially threaded (16-32mm thread length - lag effect)
• Screw Lengths: 40-70mm typical (depends on fragment size, bone quality)

Tension Band System (If Using):

• K-wires: 1.6mm (2× parallel wires through malleolar fragment into tibia)
• Wire: 18-gauge or 20-gauge stainless steel (figure-8 around K-wire ends)
• Wire Tightener: Twist wire to tighten (compresses fracture)
• Wire Cutter: Cut excess wire, bend ends (bury beneath soft tissue)

Plate System (If Vertical Fracture):

• Antiglide plate: One-third tubular (3.5mm) OR mini-fragment (2.7mm)
• Screws: Cortical screws (3.5mm or 2.7mm depending on plate)
• Plate benders: Contour plate to medial malleolus anatomy

Implant Selection

Screw Fixation (Most Common):

• Cannulated screws (4.0mm partially threaded): Standard for transverse/short oblique fractures
  • Partially threaded = lag effect (thread only in far cortex - compression)
  • Cannulated = easier placement over guidewire (less soft tissue stripping)
• Solid cortical screws (3.5mm or 4.0mm): Alternative (non-cannulated - technically harder, less common)

Screw Configuration:

• Two screws (standard): Placed perpendicular to fracture line, parallel to each other (biomechanically optimal)
• Screw spacing: 10-15mm apart (distributes stress, prevents fracture line propagation)
• Thread length: Choose partially threaded screw with thread crossing fracture line (lag compression)

Tension Band (Alternative):

• K-wires: 1.6mm diameter, 2× wires parallel, 10-15mm apart
• Wire: 18-gauge stainless steel (stronger) or 20-gauge (easier to work with)
• Figure-8 pattern: Wire loops around K-wire ends (proximal and distal), tightened to compress fracture

Plate (Vertical Fractures Only):

• One-third tubular plate: 3.5mm screws (stronger, for larger patients)
• Mini-fragment plate: 2.7mm screws (lower profile, for smaller patients or children)
• Positioning: Plate on MEDIAL surface of medial malleolus (tension side - resists shear)

Standard Positioning - Supine

Setup:

1. Patient Position: Supine on OR table
2. Hip Position: Small bump (5-10cm) under ipsilateral hip (internally rotates leg - brings medial ankle superior for access)
3. Leg Position: Leg externally rotated 20-30° (medial malleolus faces surgeon)
4. Foot Position: Secured to table OR foot hanging free (allows intraop ROM assessment)
5. Tourniquet: Upper thigh pneumatic tourniquet (inflated to 300mmHg after exsanguination)

Advantages:

• Easy Access: Medial malleolus faces directly superior (natural surgical position)
• Fluoroscopy: C-arm easily positioned (AP, lateral, mortise views)
• Bilateral Surgery: If bimalleolar/trimalleolar fracture, can access lateral malleolus without repositioning

Disadvantages:

• Leg Instability: Leg may rotate during case (need assistant to stabilize OR secure with tape/sandbag)

Alternative Positioning - Lateral Decubitus

Setup (Rarely Used):

• Patient lateral decubitus, operative side UP
• Allows simultaneous medial and lateral malleolus access (for bimalleolar fractures)
• Used in some centres for simultaneous bimalleolar access; supine remains the default in most practice worldwide

Standard Practice: Most surgeons use supine positioning for medial malleolar fractures (easier, faster setup).

Tourniquet Considerations

Standard Practice:

• Upper thigh tourniquet (300mmHg after exsanguination with Esmarch)
• Bloodless field (improves visualization, faster surgery)
• Safe time: 2 hours (most medial malleolar ORIF under 60 minutes)
• Release BEFORE closure (achieve haemostasis, prevent postop haematoma)

No Tourniquet Alternative:

• PAD patients (arterial insufficiency), sickle cell disease
• Requires meticulous haemostasis with bipolar cautery

Surface Landmarks

Palpable Structures (Mark Preoperatively):

1. Medial Malleolus: Most prominent medial ankle landmark (palpate - distal tibia medial process)
2. Tibialis Posterior Tendon: Posterior border of medial malleolus (palpate - cord posterior to malleolus, ask patient to plantarflex/invert against resistance)
3. Posterior Tibial Artery Pulse: 1-2cm posterior to medial malleolus (palpate between malleolus and Achilles tendon)
4. Medial Ankle Joint Line: 5mm distal to medial malleolar tip (palpate - tibiotalar joint)

Incision Planning:

• Position: Directly over medial malleolus OR slightly anterior (0.5-1cm anterior to center)
• Orientation: Vertical (straight) OR curved (parallels malleolar contour)
• Length: 6-8cm (allows access from distal tibia metaphysis to talar neck)
• Avoid: Directly posterior incision (crosses posterior tibial NV bundle - high nerve injury risk)

Neurovascular Anatomy

Saphenous Nerve (HIGH RISK):

• Course: Terminal branch of femoral nerve, runs WITH great saphenous vein in subcutaneous tissue
• Position at Ankle: Crosses ANTERIOR to medial malleolus (variable - 30% of patients have nerve crossing directly in surgical field)
• Branches: Multiple small branches (innervate medial ankle and medial midfoot skin)
• Surgical Relevance: An anatomically constant branch crosses the anterior border of the medial malleolus, within the skin incision (Peng et al, PLoS One 2024) - it is at risk during the subcutaneous step and should be identified and protected
• Injury Consequences: Painful neuroma (hyperaesthesia medial ankle/foot), sensory loss (medial ankle/foot), pillar pain

Posterior Tibial Neurovascular Bundle:

• Position: 1-2cm POSTERIOR to medial malleolus (deep to flexor retinaculum)
• Contents:
  • Posterior tibial artery: Pulse palpable posterior to malleolus
  • Posterior tibial nerve: Terminal branches (medial plantar nerve, lateral plantar nerve)
  • Tendons: Tibialis posterior (most anterior), FDL, FHL (most posterior) - "Tom, Dick, And Harry" from anterior to posterior
• At Risk: If dissection extends too far posteriorly (>1-2cm posterior to malleolar tip), can injure nerve
• Protection: Stay ANTERIOR to medial malleolus during dissection (nerve is posterior - safe)

Deltoid Ligament Complex:

• Superficial Deltoid (Fan-Shaped):
  • Origin: Medial malleolus anterior colliculus
  • Insertions: Navicular (tibionavicular ligament), sustentaculum tali (tibiocalcaneal), talus (superficial posterior tibiotalar)
  • Function: Resists talar eversion (secondary restraint)
• Deep Deltoid (Cord-Like):
  • Origin: Medial malleolus posterior colliculus (intercollicular groove)
  • Insertion: Medial talus (deep posterior tibiotalar)
  • Function: PRIMARY restraint to lateral talar shift (CRITICAL for ankle stability)

Surgical Importance:

• Deep deltoid rupture + lateral malleolar fracture = "bimalleolar equivalent" (surgical treatment required even without medial malleolar fracture)
• If medial malleolar fracture anatomically reduced, deltoid tension restored (no separate deltoid repair needed UNLESS deltoid avulsed from talus)

Medial Malleolus Anatomy

Bony Anatomy:

• Anterior colliculus: Anterior prominence (superficial deltoid origin)
• Posterior colliculus: Posterior prominence (deep deltoid origin)
• Intercollicular groove: Between colliculi (deep deltoid fibers course through)
• Articular surface: Medial plafond (30-40% of tibiotalar joint weight-bearing surface)

Fracture Patterns (Lauge-Hansen):

• Transverse (SER, PER): Most common (70%), fracture line perpendicular to tibial long axis, stable fixation with screws
• Vertical (SAD): 15%, fracture line parallel to tibial axis, unstable fixation with screws (requires plate)
• Oblique (PAB): 10%, fracture line 45° oblique, variable stability
• Comminuted: 5%, multiple fragments, tension band or plate fixation

Step 1: Skin Incision and Superficial Dissection

Incision:

• Mark Medial Malleolus: Palpate prominent medial malleolus, mark center
• Incision Position: Vertical incision directly over medial malleolus OR 5mm anterior (allows easier exposure while avoiding posterior tibial NV bundle)
• Incision Length: 6-8cm (from distal tibia metaphysis 3cm proximal to malleolus, extending to talar neck)
• Alternative: Curved incision (parallels malleolar contour - slightly better cosmesis, same exposure)

Skin Incision:

• 15 blade scalpel, incise through dermis
• Subcutaneous dissection (2-3mm depth to deep fascia)
• Ligate superficial veins (great saphenous vein may be in field - preserve if possible, ligate if necessary)

Identify Saphenous Nerve (CRITICAL STEP):

During subcutaneous dissection:

1. Look for saphenous nerve: Small white nerve (1-2mm diameter) in subcutaneous fat, running with or near great saphenous vein
2. Variable Position: May cross anteriorly (30% of cases - directly in field), may be slightly medial or anterior to incision
3. If Identified: Place vessel loop around nerve, gentle retraction throughout case (protect from stretch/division)
4. If Not Seen: Assume it's nearby - gentle subcutaneous tissue handling, minimize traction

Step 2: Deep Fascial Incision and Periosteal Exposure

Incise Deep Fascia:

• Identify deep fascia (white glistening layer superficial to periosteum)
• Incise fascia longitudinally (parallel to skin incision - full length)
• Elevate fascial edges (exposes periosteum over medial malleolus)

Identify Fracture Line:

• Palpate medial malleolus (fracture line may be visible through periosteum - hematoma)
• Assess fracture pattern: Transverse vs vertical vs oblique (determines fixation strategy)

Periosteal Incision:

1. Incise periosteum longitudinally (along anterior border of medial malleolus)
2. Elevate periosteum anteriorly (Freer elevator - subperiosteal dissection)
3. Preserve Deltoid Ligament: If deltoid intact posteriorly, do NOT strip deltoid from malleolus (preserve attachment - no need to elevate posteriorly unless assessing deltoid injury)

Expose Fracture:

• Subperiosteal elevation anteriorly exposes fracture site
• Use small Hohmann retractors (retract soft tissue anteriorly and posteriorly - visualize fracture edges)
• Evacuate hematoma (suction, curettage - improves visualization)

Step 3: Fracture Reduction

Reduction Maneuvers:

For Transverse/Short Oblique Fractures:

1. Clean Fracture Surfaces: Curette hematoma, fibrous tissue from fracture edges (promotes bone-to-bone contact)
2. Reduce Malleolar Fragment: Manually push malleolar fragment proximally (usually displaced distally + rotated)
   • Align articular surface (medial plafond must be flush with tibia - check on mortise fluoroscopy)
3. Provisional Fixation: 1.6mm or 2.0mm K-wire from malleolar tip into tibia (holds reduction while checking fluoroscopy)

For Vertical Fractures (SAD Pattern):

1. Disimpact Fragment: Vertical fractures often impacted (fragment driven proximally) - use small osteotome or elevator to disimpact
2. Reduce Fragment: Push fragment distally (restore malleolar length), align articular surface
3. Provisional Fixation: K-wire perpendicular to fracture line (resists shear during definitive fixation)

Fluoroscopy Check (CRITICAL):

• Mortise View: Medial clear space <4mm (if >4mm, fracture not reduced OR deltoid ruptured)
• AP View: Malleolar fragment aligned with tibia, no articular step
• Lateral View: Assess talar position (confirm no anterior/posterior shift - suggests syndesmotic injury)

Reduction Quality:

• Anatomic reduction required (>2mm step = post-traumatic arthritis risk 60% at 10 years)
• If cannot achieve anatomic reduction: Re-assess fracture (may need plate for comminution, may need medial malleolar osteotomy if OCL or impaction)

Step 4: Definitive Fixation - Cannulated Lag Screws (Standard Technique)

Guidewire Placement:

Screw 1 (Proximal):

1. Entry point: Distal tibia 2-3cm proximal to fracture line, slightly anterior on medial malleolus
2. Trajectory: Aim perpendicular to fracture line (crosses fracture obliquely), exits posterior cortex
3. Drill 1.6mm guidewire (check fluoroscopy - wire crosses fracture, good bone purchase distal fragment)

Screw 2 (Distal):

1. Entry point: 10-15mm distal to Screw 1, also slightly anterior
2. Trajectory: Parallel to Screw 1, perpendicular to fracture line
3. Drill 1.6mm guidewire (check fluoroscopy)

Key Principles:

• Screws perpendicular to fracture line (maximizes compression - lag effect)
• Screws parallel to each other (distributes load evenly)
• 10-15mm spacing (prevents stress concentration)

Drilling and Screw Insertion:

For Each Screw:

1. Measure Screw Length: Depth gauge over guidewire (to posterior cortex)
2. Cannulated Drill: 3.2mm drill over guidewire (pilot hole for 4.0mm screw)
   • Drill NEAR cortex only (stop before drilling far cortex - creates lag effect)
   • Far cortex will be threaded by screw (compression as screw tightens)
3. Insert Cannulated Screw: 4.0mm partially threaded (16-32mm thread length)
   • Thread must cross fracture line (lag compression)
   • Tighten screw (feel compression - fracture edges approximate)
4. Check Fluoroscopy: Screw position (not intra-articular, good purchase, crosses fracture)

Remove K-wires:

• Provisional K-wires removed (screws provide definitive fixation)

Final Fluoroscopy:

• Mortise View: Medial clear space <4mm (fracture reduced), screws do not violate joint
• AP View: Fracture reduced, screw heads buried (not prominent)
• Lateral View: Screws do not penetrate too far posteriorly (risk posterior tibial NV bundle)

Step 5: Alternative Fixation - Tension Band (If Comminuted)

K-wire Insertion:

1. Insert 2× K-wires (1.6mm) from distal malleolar fragment into tibia
   • Wires parallel, 10-15mm apart
   • Wires perpendicular to fracture line (crosses into proximal tibia - good purchase)
2. Cut K-wires 5mm proud of bone (will bend later to bury)

Figure-8 Wire Application:

1. Pass 18-gauge or 20-gauge stainless steel wire deep to K-wires at proximal and distal ends
2. Create figure-8 pattern (loops around proximal K-wire ends, crosses midline, loops around distal K-wire ends)
3. Tighten wire (wire tightener or needle driver) - compresses fracture
4. Cut excess wire, bend wire ends flat (bury beneath soft tissue - reduce prominence)

Bend K-wire Ends:

• Bend K-wire ends 90° (toward bone - bury tips to reduce subcutaneous prominence)

Check Fluoroscopy:

• Fracture compressed (gap closed)
• K-wires and wire do not violate joint

Step 6: Alternative Fixation - Antiglide Plate (If Vertical Fracture)

Plate Positioning:

1. Plate on Tension Side: Place plate on MEDIAL surface of medial malleolus (vertical fractures = shear forces, plate resists shear)
2. Contour Plate: Bend plate to match medial malleolar anatomy (one-third tubular plate malleable)

Screw Insertion:

1. Proximal Screws: 2-3 screws into tibia proximal to fracture (bicortical purchase)
2. Distal Screws: 1-2 screws into malleolar fragment distal to fracture
3. Lag Screw Across Fracture (Optional): One screw through plate crosses fracture (lag effect)

Check Fluoroscopy:

• Fracture reduced (plate provides buttress)
• Plate does not violate joint
• Screws good purchase (bicortical)

Step 7: Assess Deltoid Ligament (If Bimalleolar Equivalent)

When to Assess:

• Lateral malleolar fracture ORIF completed, but medial clear space still >4mm on fluoroscopy
• Clinical suspicion of deep deltoid rupture (medial ankle tenderness, ecchymosis, but NO medial malleolar fracture)

Technique:

1. Extend medial incision distally (to deltoid insertion on talus)
2. Incise deep fascia, identify deltoid ligament (fan-shaped superficial deltoid, cord-like deep deltoid)
3. Assess deltoid integrity:
   • Superficial deltoid: If torn, can often be left (secondary stabilizer)
   • Deep deltoid: If ruptured, MUST repair (primary restraint to lateral talar shift)

Deltoid Repair (If Deep Deltoid Ruptured):

1. Identify Tear: Deep deltoid usually avulses from talus (less commonly from tibia)
2. Suture Anchor Insertion: 3.5mm suture anchor into medial talus (at deltoid insertion site)
3. Suture Deltoid: Pass suture through deltoid ligament (mattress sutures), tie down (re-tensions deltoid)
4. Check Fluoroscopy: Medial clear space should reduce to <4mm after deltoid repair

Step 8: Final Checks and Closure

Remove Provisional K-wires:

• All provisional K-wires removed (definitive fixation complete)

Assess Stability:

• Manual stress (varus/valgus, AP drawer) - ankle should be stable (no opening medial joint)
• Assess ROM (passive dorsiflexion/plantarflexion - smooth motion, no crepitus)

Fluoroscopy Final Check:

• Mortise View: Medial clear space <4mm, fracture reduced, hardware not intra-articular
• AP View: Fracture anatomically reduced, screws parallel, good position
• Lateral View: Talar position normal (no anterior/posterior shift)

Irrigation:

• Copious saline irrigation (wash out hematoma, bone debris)

Haemostasis:

• Release tourniquet (identify bleeding vessels)
• Bipolar cautery (coagulate vessels)
• Check posterior tibial artery pulse (palpate posterior to medial malleolus - ensure intact)

Closure:

• Periosteum: 2-0 Vicryl interrupted (re-approximate periosteum over malleolus - not critical)
• Deep Fascia: 2-0 Vicryl interrupted (reduces dead space)
• Subcutaneous: 3-0 Vicryl interrupted (invert skin edges, meticulous haemostasis)
• Skin: 4-0 Nylon vertical mattress OR 4-0 Monocryl subcuticular

Dressing:

• Sterile gauze, cotton padding (generous - absorb drainage)
• Posterior splint (short leg - ankle neutral, well-padded)
• Elevate leg postop (reduce swelling)

Pre-Closure Verification

Fluoroscopy Final Check:

• Mortise: Medial clear space <4mm (fracture reduced, deltoid tensioned)
• AP: Fracture anatomically reduced, hardware position acceptable
• Lateral: Talar position normal, no hardware prominence posteriorly

Hardware Position:

• Screws/plate do NOT violate joint (intra-articular hardware = arthritis)
• Screws parallel (distributes load)
• Screw heads buried (minimize subcutaneous prominence - though 30% removal rate regardless)

Neurovascular:

• Posterior tibial artery pulse present (palpate posterior to medial malleolus)
• Saphenous nerve protected (vessel loop if identified, gentle tissue handling if not seen)

Deltoid Assessment (If Applicable):

• Medial clear space <4mm after fixation (if >4mm, assess for deltoid rupture and repair if needed)

Haemostasis:

• Tourniquet deflated, bleeding controlled
• No active bleeding

Layer-by-Layer Closure

Deep Layers:

1. Periosteum: 2-0 Vicryl × 3-4 interrupted (optional - not critical)
2. Deep Fascia: 2-0 Vicryl × 4-5 interrupted

Superficial Layers: 3. Subcutaneous: 3-0 Vicryl × 6-8 interrupted (invert edges, careful haemostasis) 4. Skin: 4-0 Nylon vertical mattress × 8-10 OR 4-0 Monocryl subcuticular

Splint:

• Posterior short leg splint (ankle neutral, well-padded)
• Non-weight-bearing instructions (crutches 6 weeks)

Intraoperative Complications

Saphenous Nerve Injury (one of the commonest iatrogenic complications of this approach)

• Mechanism: Not identified during subcutaneous dissection, divided during incision, or stretched during retraction
• Presentation: Cannot test intraop (patient asleep), postop sensory loss medial ankle/foot, painful neuroma (hyperesthesia)
• Management:
  • If recognized intraop (nerve cut): Primary repair (microsurgical 8-0 nylon - approximate nerve ends)
  • If recognized postop: Observation 3-6 months (many neuropraxia improve), persistent painful neuroma = excision + nerve burial
• Prevention: Active search during subcutaneous dissection, vessel loop if identified, gentle tissue handling

Posterior Tibial Nerve Injury (<1%)

• Mechanism: Dissection extended too far posteriorly (>2cm posterior to medial malleolus), drill bit penetrates posterior cortex into NV bundle
• Presentation: Postop weakness FHL/FDL (toe flexion), numbness plantar foot
• Management: Usually neuropraxia (observation 3-6 months), EMG at 6 weeks if no improvement
• Prevention: Stay anterior during dissection, check drill depth on lateral fluoroscopy (avoid excessive posterior penetration)

Posterior Tibial Artery Injury (<1%)

• Mechanism: Same as nerve (dissection too posterior, drill penetration)
• Presentation: Loss of posterior tibial pulse, foot ischemia (rare - foot has collateral blood supply via dorsalis pedis)
• Management: If pulseless postop, urgent vascular surgery consult (primary repair vs observation if dorsalis pedis pulse intact)
• Prevention: Stay anterior, check PT pulse after tourniquet release

Inadequate Reduction (5-10%)

• Mechanism: Soft tissue interposition (periosteum, deltoid), comminution, inadequate visualization
• Presentation: Fluoroscopy shows medial clear space >4mm, articular step >2mm
• Management: Remove hardware, re-reduce fracture, re-fix (may need different fixation method - e.g., plate if screws inadequate)
• Prevention: Direct visualization of fracture reduction, systematic fluoroscopy (mortise view critical)

Early Postoperative Complications (0-6 weeks)

Wound Complications (5-10%)

• Mechanism: Medial malleolus subcutaneous (minimal soft tissue coverage), tension on closure, poor vascularity (diabetes, smoking)
• Presentation: Wound edge necrosis, dehiscence, drainage
• Risk Factors: Diabetes (doubles risk), smoking (triples), obesity, fracture blisters operated through
• Management:
  • Superficial dehiscence: Local wound care, allow secondary healing
  • Deep dehiscence (hardware exposed): Possible flap coverage (medialis pedis flap), hardware retention if fracture stable
• Prevention: Avoid operating through fracture blisters (wait for wrinkle sign), meticulous tissue handling, no tension on closure

Infection (2-5%)

• Presentation: Wound erythema, purulent drainage, fevers, pain out of proportion
• Organisms: Staph aureus (70%), Strep species (20%), polymicrobial (diabetes)
• Diagnosis: Wound culture, blood cultures if systemic, CRP/ESR elevated
• Management:
  • Superficial (cellulitis): Oral anti-staphylococcal antibiotics (e.g. flucloxacillin or, in MRSA-prevalent settings, an agent guided by local antibiogram) for 1-2 weeks
  • Deep (hardware contamination, fracture stable): Surgical debridement with hardware retention (debridement, antibiotics and implant retention principle) plus a prolonged course of culture-directed IV/oral antibiotics
  • Severe (osteomyelitis, fracture unstable): Hardware removal, external fixation, delayed ORIF after infection cleared
• Prevention: Single-dose perioperative prophylaxis at induction (first-generation cephalosporin such as cefazolin per WHO/ASHP/SIGN guidance, with glycopeptide cover where MRSA is endemic), avoid operating through fracture blisters, optimise diabetes preoperatively

Loss of Reduction (2-5%)

• Mechanism: Inadequate fixation (osteoporotic bone, comminution), premature weight-bearing, hardware failure
• Presentation: Postop X-rays (week 2-6) show fracture displacement, widened medial clear space
• Management: Revision ORIF (if early, under 4 weeks - bone not yet healed), accept malunion (if late, over 6 weeks, elderly low-demand)
• Prevention: Adequate fixation (bone graft if osteoporotic), strict NWB compliance, patient counseling

Late Postoperative Complications (>6 weeks)

Hardware Prominence (30-40%)

• Mechanism: Medial malleolus subcutaneous (minimal soft tissue coverage), screw/plate/wire prominence, patient discomfort with shoewear
• Presentation: Painful bump medial ankle (screw head palpable), skin irritation (redness over hardware)
• Diagnosis: Clinical (palpable hardware), X-ray (confirms hardware position)
• Management: Hardware removal (>12 months postfracture - bone healed), counsel patient preop (30-40% removal rate is expected)
• Timing: Remove after fracture union (12-18 months), earlier if severe symptoms

Malunion (5-10%)

• Mechanism: Inadequate reduction accepted, loss of reduction postop (see above)
• Presentation: Valgus ankle deformity, widened medial clear space, medial ankle pain
• Diagnosis: Weight-bearing X-rays (mortise shows medial clear space >4mm, valgus talar tilt)
• Consequences: Post-traumatic ankle arthritis - quality of articular reduction is the most consistent long-term predictor of arthritis and poor function (Stufkens et al, Injury 2011), so residual mortise incongruity should not be accepted
• Management:
  • Symptomatic malunion: Corrective osteotomy (cut malleolus, re-reduce, re-fix) OR ankle arthrodesis (if arthritis established)
• Prevention: Anatomic reduction intraop, systematic fluoroscopy

Non-Union (<2%)

• Mechanism: Rare (medial malleolus good blood supply), risk factors smoking, diabetes, inadequate fixation
• Presentation: Persistent medial ankle pain (3-6 months postop), fracture line visible on X-ray (no bridging callus)
• Diagnosis: X-ray at 3-6 months (persistent fracture line), CT confirms (no trabecular bridging)
• Management: Revision ORIF (remove hardware, freshen fracture surfaces, bone graft, re-fix with plate or screws)
• Prevention: Smoking cessation (6 weeks preop, 12 weeks postop), optimize diabetes, adequate fixation

Post-Traumatic Arthritis (10-30% at 10 years)

• Mechanism: Intra-articular injury (cartilage damage at time of fracture), residual articular incongruity (step >2mm)
• Presentation: Chronic ankle pain, stiffness, swelling (develops 2-10 years postinjury)
• Diagnosis: Weight-bearing X-rays (joint space narrowing, osteophytes, subchondral sclerosis)
• Management:
  • Conservative: NSAIDs, bracing (AFO), activity modification, intra-articular corticosteroid injections
  • Surgical: Ankle arthrodesis (young active) OR total ankle replacement (elderly low-demand)
• Prevention: Anatomic reduction (articular step <2mm), early ROM (prevent stiffness - start 6 weeks postop)

Immediate Postoperative Care (Day 0-1)

Recovery Room:

• Neurovascular check (posterior tibial pulse, sensation medial foot - document)
• Pain control: Popliteal nerve block (sciatic block - 12-18 hour analgesia), oral opioids
• X-ray (AP, lateral, mortise - confirm hardware position, reduction maintained)

Ward Care:

• Elevation: Leg elevated above heart (24-48 hours - CRITICAL for swelling reduction, fracture blister prevention)
• Cryotherapy: Ice packs 20 min Q2h (reduces swelling, pain)
• DVT Prophylaxis: Enoxaparin 40mg SC daily OR rivaroxaban 10mg PO daily (until mobile)
• Splint: Posterior short leg splint (ankle neutral, well-padded - maintain 2 weeks)

Discharge Criteria (Day 0-1):

• Pain controlled (NRS under 4/10 on oral meds)
• Neurovascularly intact
• Safe mobilization (crutches NWB - patient independent)
• Understands NWB restrictions (6 weeks minimum)

Outpatient Follow-up Protocol

Week 2:

• Wound Check: Remove splint/dressing, assess for infection, dehiscence
• Suture Removal: If interrupted nylon (vertical mattress), remove alternate sutures OR leave all 2 weeks
• X-ray: AP, lateral, mortise (assess hardware position, early healing)
• Splint Change: Re-apply posterior splint OR transition to CAM boot (if wound healthy, swelling improved)
• Weight-Bearing: Continue NWB (crutches)

Week 6:

• X-ray: AP, lateral, mortise (assess fracture healing - expect callus formation)
• Clinical Exam: Palpate fracture site (should be non-tender), assess ROM (ankle likely still stiff)
• Transition to CAM Boot: Remove splint, apply CAM boot
• Weight-Bearing: Begin weight-bearing as tolerated (WBAT) in CAM boot (if fracture shows healing on X-ray)
• Physiotherapy: Begin ankle ROM exercises (dorsiflexion/plantarflexion), no resistance

Week 12:

• X-ray: Confirm union (bridging callus on 3/4 cortices)
• Weight-Bearing: Full weight-bearing (FWB) in regular shoes (if union confirmed)
• Physiotherapy: Progress to strengthening (Theraband resistance, proprioception training)

Month 6:

• Final X-ray: Confirm mature union, assess for hardware complications
• ROM Assessment: Dorsiflexion 70-80% of contralateral, plantarflexion 80-90%
• Return to Activity: Unrestricted (union solid)
• Hardware Removal Counseling: Discuss hardware removal (30-40% will request - symptomatic prominence)

Month 12-18:

• Hardware Removal: If symptomatic (painful hardware prominence, shoe wear irritation)
  • Timing: After union confirmed (>12 months)
  • Technique: Same incision, remove screws/plate/wire, close

Physiotherapy Protocol

Phase 1 (Weeks 0-6): Protection

• Goals: Protect fracture, prevent DVT, maintain knee/hip ROM
• Exercises:
  • Toe wiggling (prevent toe stiffness)
  • Ankle pumps (calf pump - DVT prevention) - gentle, pain-free
  • Knee ROM (flexion/extension)
• Restrictions: NWB (crutches), ankle immobilized (splint/boot)

Phase 2 (Weeks 6-12): Progressive Weight-Bearing + ROM

• Goals: Restore ankle ROM, progressive weight-bearing
• Exercises:
  • Active ankle ROM (dorsiflexion/plantarflexion - seated, no resistance)
  • WBAT progression (partial → full weight-bearing in CAM boot)
  • Gait training (normalize gait pattern - reduce limp)
• Restrictions: CAM boot until 12 weeks (union confirmed)

Phase 3 (Months 3-6): Strengthening + Proprioception

• Goals: Restore strength, improve balance
• Exercises:
  • Theraband resistance (plantarflexion, dorsiflexion, inversion, eversion)
  • Proprioception (single-leg stance, wobble board - prevent chronic instability)
  • Functional activities (stairs, uneven ground)
• Restrictions: No running/jumping until month 6

Phase 4 (Months 6-12): Return to Sport

• Goals: Return to pre-injury activity level
• Exercises: Sport-specific training (agility drills, plyometrics if appropriate)
• Return to Sport: Low-impact OK (cycling, swimming), high-impact gradual (running at 6 months, contact sports 9-12 months)

Return to Function, Work and Driving (Global Guidance)

Return to Work:

• Sedentary: 6-8 weeks (desk work, minimal ambulation)
• Light Manual: ~3 months (standing work, occasional lifting under 10kg)
• Heavy Manual: ~6 months (prolonged standing, repetitive lifting, manual labour)

Driving:

• Operative (brake-pedal) side fracture: typically 6-9 weeks, only once the patient can perform an emergency stop safely - brake-reaction-time studies support resuming once weight-bearing and out of a cast/boot
• Non-pedal side fracture (automatic transmission): often 2-4 weeks once comfortable
• Advise patients to confirm with their insurer/licensing authority, as medico-legal driving rules differ by jurisdiction

Hardware Removal: Counsel patients pre-operatively that a meaningful minority (literature ~10-30%) request hardware removal for symptomatic prominence, because the medial malleolus is subcutaneous. Defer removal until union is confirmed (usually after 12 months).