Surgical Scrub Guide

Right Ankle Bimalleolar Fracture - ORIF

PATIENT SNAPSHOT

WHY ORIF IS INDICATED

• ~10% nonunion with closed treatment
• 20% have intraarticular injuries to talus/tibia that are missed without surgical exploration
• Randomized prospective long-term studies confirm superior outcomes with ORIF over nonoperative treatment for bimalleolar fractures

TIMING NOTE

DANIS-WEBER CLASSIFICATION (know before you scrub)

• Type A - fibula fracture at or below the plafond (infrasyndesmotic) - internal rotation + adduction mechanism
• Type B - oblique fibula fracture at level of syndesmosis (transsyndesmotic) - external rotation mechanism - most common, likely what Brundha has
• Type C - fibula fracture above the syndesmosis (suprasyndesmotic) - syndesmosis always disrupted

SETUP & POSITIONING

• Position: Supine, ipsilateral hip bumped to internally rotate the limb OR lateral decubitus depending on surgeon preference
• Tourniquet: Upper thigh pneumatic tourniquet (inflate ~250-300 mmHg or 100 mmHg above systolic)
• C-arm: Standard ankle views - AP, mortise (15-20° internal rotation), lateral
• Limb prep: Knee to toes, free-draped
• Table: Radiolucent

IMPLANTS TO HAVE READY

Lateral Malleolus (Fibula)

• 1/3 semitubular plate, 3.5 mm (standard lateral plating) - most common construct
• 3.5 mm cortical screws (multiple lengths - have 30 mm to 55 mm range)
• 3.5 mm lag screws (if oblique fracture - interfragmentary compression before plating)
• Optional: Posterior antiglide plate if posterolateral approach chosen

Medial Malleolus (CC Screw)

• Two 4.0 mm cannulated cancellous (CC) screws - standard fixation, oriented perpendicular to fracture line
• Guidewires x2 (for CC screws)
• Alternative: 3.5 mm bicortical lag screws or tension band wiring if fragment is small

Syndesmosis (Have Available - assess intraoperatively)

• One or two 3.5 mm or 4.5 mm cortical syndesmotic screws (quadricortical or tricortical)
• Usually placed 2-4 cm above the plafond, through distal plate hole if possible
• Assess with Cotton test + external rotation stress under fluoro after lateral fixation

SURGICAL SEQUENCE (Campbell's Technique 59.1)

Step 1 - Lateral Malleolus First (standard order)

Fix lateral before medial UNLESS the lateral is comminuted, in which case fix medial first to avoid over-reduction of the coronal plane.

1. Incision: Lateral longitudinal incision over distal fibula
   • Protect the superficial peroneal nerve - identify and retract
   • Alternatively: posterolateral incision for antiglide plating (avoids palpable implant over lateral surface)
   • Expose fibula extraperiosteally
2. Fracture reduction:
   • Reduce fracture and hold with reduction clamp / K-wires provisionally
   • If oblique fracture with good bone stock - place one or two 3.5 mm lag screws anterior to posterior (1 cm apart, at least 1 cm from fracture line) for interfragmentary compression first
3. Plate application:
   • Apply 1/3 semitubular plate to lateral surface of fibula
   • Proximal screws: bicortical fixation (3.5 mm cortical)
   • Distal screws: bicortical where possible
   • Confirm length, rotation and alignment on fluoroscopy (AP + mortise + lateral)
4. Intraoperative syndesmosis assessment (Cotton test + external rotation stress):
   • Hook the fibula and pull laterally while stabilizing the tibia
   • >3-4 mm displacement = syndesmotic fixation needed
   • If stable: proceed to medial side
   • If unstable: place syndesmotic screw through distal plate hole, 2-4 cm above plafond, parallel to joint (NOT in dorsiflexion)

Step 2 - Medial Malleolus (CC Screw Fixation - Technique 59.2)

1. Incision: Medial longitudinal incision directly over medial malleolus, curving slightly anteriorly
   • Protect the saphenous nerve and vein anteriorly
   • Identify fracture, clear hematoma and any soft tissue interposition (periosteum can block reduction - clean the fracture site)
2. Reduction:
   • Direct reduction with periosteal elevator
   • Hold with two K-wires bent to stay out of the way (as per AO technique, Fig 59.6)
3. Guidewire placement (for cannulated screws):
   • Drill 3.2 mm guide hole perpendicular to fracture line
   • Measure depth
   • Two parallel guidewires
4. Screw insertion:
   • Insert two 4.0 mm CC screws without tapping
   • Screws oriented perpendicular to fracture - lag effect for compression
   • Remove K-wires after screws tightened
   • If fragment tends to rotate: add a smaller screw or K-wire
5. Confirm on fluoroscopy: Mortise view - assess medial clear space (normal ≤4 mm), tibiotalar congruence, screw position (should not enter joint)

FLUOROSCOPIC CHECKPOINTS

NERVES AT RISK - KNOW BEFORE YOU CUT

SYNDESMOTIC FIXATION - QUICK REFERENCE

• Fibula fracture above the distal tibiofibular joint (Weber C)
• Cotton test positive (>3-4 mm displacement)
• External rotation stress test positive on fluoro after lateral fixation
• Syndesmotic disruption extending >5 cm proximal to plafond

• 1-2 cortical screws (3.5 or 4.5 mm), placed 2-4 cm above plafond
• Through both fibular cortices + 1 or 2 tibial cortices
• Ankle in neutral/slight dorsiflexion during placement (prevents over-compression)
• Reduce syndesmosis with pointed reduction forceps before drilling
• Confirm fibular position in incisura on axial fluoro/CT if uncertain

INSTRUMENTS NEEDED

• Standard trauma set
• Small fragment set (3.5 mm screws, 1/3 tubular plates)
• Cannulated screw set (4.0 mm CC for medial malleolus)
• Large pointed reduction forceps x2
• Bone hook
• K-wires (1.6 mm and 2.0 mm)
• Drill bits: 3.2 mm (for CC guidewire / screw prep), 2.5 mm
• Depth gauge, tap (if non-cannulated)
• C-arm
• Small Hohmann retractors x2

POSTOPERATIVE PLAN (standard)

• Below-knee backslab initially (wait for swelling to settle)
• Non-weight bearing x 6 weeks
• Convert to boot at 6 weeks if union progressing
• Partial WB at 6-8 weeks, full WB at 10-12 weeks
• Physiotherapy for ROM and strengthening

POTENTIAL INTRAOPERATIVE ISSUES

Trimalleolar Fracture - The Posterior Malleolus (Volkmann's Fragment)

WHAT IS IT?

• Posterior displacement of the talus
• Lateral displacement of the talus
• External rotation + supination of the foot
• Loss of tibiotalar contact area = rapid post-traumatic arthritis if left unreduced

DO YOU FIX IT? - THE DECISION

Key insight: Fixing the posterior malleolus provides greater syndesmotic stability than a syndesmotic screw - it reconstructs the native PITFL attachment.

THE POSTERIOR MALLEOLUS FRAGMENT

SURGICAL SEQUENCE - CRITICAL POINT

Fix the posterior malleolus FIRST before lateral or medial malleolus (if it requires fixation).

APPROACHES TO THE POSTERIOR MALLEOLUS

Option 1 - Posterolateral Approach (most common, preferred for laterally located fragments)

• Incision: 7.5 cm longitudinal, lateral to the Achilles tendon
• Internervous plane: between peroneal tendons (lateral) and Achilles/FHL (medial)
• Steps:
  1. Protect the sural nerve
  2. Retract Achilles tendon medially, peroneal tendons laterally
  3. Elevate flexor hallucis longus (FHL) off the posterior tibia - FHL is your depth guide to the posterior malleolus
  4. Expose the posterior tibial surface directly
• Advantage: Can fix posterior malleolus AND lateral malleolus through the same posterolateral window simultaneously

Option 2 - Posteromedial Approach (for medially located fragments)

• Incision: Posteromedial, adjacent to Achilles, posterior to the medial malleolus
• Incise posterior tibial tendon sheath adjacent to posterior border of tibia
• Displace the medial malleolar fragment and dissect subperiosteally to access posterior malleolus
• Limitation: Fixation is limited to screws or minifragment plates (less mechanical advantage)

Option 3 - Indirect reduction from anteromedial + anterior-to-posterior screws

• Used for smaller fragments
• K-wires inserted 1-3 cm above anterior tibial lip, directed anterior to posterior
• Small fragment screws from anterior to posterior

FIXATION TECHNIQUE (Campbell's Technique 59.4)

If approaching posterolaterally (preferred for large fragments):

1. Establish normal tibiotalar relationship - anterior traction on foot, adduction and inversion
2. Use a joystick to correct the proximal displacement of the posterior lip
3. Hold reduction with K-wires
4. Fix with one or two lag screws from posterior to anterior into tibial metaphysis

1. Posterior antiglide plate - preferred for biomechanical advantage (small buttress/minifragment plate applied to posterior tibial surface)

If approaching anterior to posterior (for small fragments):

• Two K-wires from anterior, 1-3 cm above anterior tibial lip, directed posteriorly to engage fragment
• Drill through both fragments, measure depth, insert small fragment screw with lag technique (over-drill anterior cortex if not using a partially-threaded screw)
• Avoid partially-threaded screw from anterior to posterior - the threads will sit across the fracture and not compress it; use a fully threaded screw in lag technique instead

IMPLANTS TO ADD TO YOUR TRAY (if trimalleolar)

STRUCTURES AT RISK - POSTERIOR APPROACHES

AFTER POSTERIOR FIXATION

• Proceed to lateral malleolus ORIF + plating (same posterolateral wound can handle both)
• Then medial malleolus CC screw fixation via anteromedial incision
• Inspect articular surface through anteromedial incision at the end to confirm anatomic reduction
• Assess syndesmosis - in a trimalleolar fracture, fixing the posterior malleolus may render the syndesmosis stable (because PITFL is now re-tensioned) - still do Cotton test to confirm

QUICK MEMORY AID

TRIMALLEOLAR = Bi + Posterior lip (Volkmann's)
Fragment pulled by PITFL → posterolateral location
Fix >25% articular surface OR any posterior talar subluxation
Sequence: Posterior FIRST → Lateral → Medial
Approach: Posterolateral (lateral to Achilles) - protect sural nerve, retract FHL
Fix: Posterior to anterior lag screws OR posterior antiglide plate