Open Tibial Fractures

Incidence

• Open fractures: 10-15% of all tibial shaft fractures
• Tibia is most common long bone with open injury (subcutaneous location)
• Male predominance: 3:1, peak age 20-40 years
• Motorcycle accidents: Most common high-energy cause in Australia

Mechanism of Injury

• High energy: MVA, motorcycle, pedestrian vs car
• Moderate energy: Sports injuries, falls
• Low energy: Simple fall with puncture wound (Type I)

Risk Factors for Infection

• Type IIIB/IIIC classification
• Delay in antibiotics over 1 hour
• Inadequate debridement
• Delay in soft tissue coverage beyond 72 hours
• Smoking, diabetes, peripheral vascular disease
• Farm or water contamination

Tibial Anatomy Relevant to Open Fractures

Why the Tibia is Vulnerable:

• Subcutaneous anteromedial surface: Minimal soft tissue coverage over medial tibia
• Watershed zone distally: Poor blood supply to distal third
• Single bone of weight-bearing: High mechanical demands

Blood Supply:

• Nutrient artery: Enters posterior cortex, runs proximally - supplies inner 2/3
• Periosteal vessels: Supply outer 1/3 of cortex
• Endosteal supply: Disrupted by IM nailing but usually adequate healing

Soft Tissue Compartments: The leg has 4 compartments - all at risk in open tibial fractures:

1. Anterior: Tibialis anterior, EDL, EHL, deep peroneal nerve
2. Lateral: Peroneus longus and brevis, superficial peroneal nerve
3. Superficial posterior: Gastrocnemius, soleus, plantaris
4. Deep posterior: Tibialis posterior, FDL, FHL, posterior tibial nerve/vessels

Pathophysiology of Open Fractures

Zone of Injury:

• Extends beyond visible wound margins
• High-energy mechanisms create larger zones of devitalized tissue
• Periosteal stripping compromises blood supply to bone

Contamination vs Infection:

• Contamination = presence of bacteria (inevitable)
• Infection = bacterial multiplication with tissue invasion
• Goal: Prevent contamination from becoming infection

Time-dependent changes:

• 0-6 hours: Contamination phase - bacteria present but not established
• 6-12 hours: Bacterial multiplication begins
• Over 12 hours: Biofilm formation, infection establishing
• Early antibiotics prevent bacterial establishment regardless of surgery timing

Gustilo-Anderson Classification (Assessed Intraoperatively)

Differentiating IIIA from IIIB

Type IIIC - Vascular Injury

Defining feature: Arterial injury requiring repair, regardless of wound size

Assessment:

• Absent or diminished distal pulses
• Cool, pale foot
• Prolonged capillary refill over 3 seconds
• Ankle-brachial index under 0.9 (if measurable)

Critical Decision Points:

• Warm ischemia time over 6 hours leads to high amputation rate
• Consider shunting for temporary perfusion if delay to definitive repair
• Revascularization before or concurrent with skeletal stabilization

Initial ED Assessment

Primary Survey Essentials:

• ATLS assessment - polytrauma common with high-energy mechanisms
• Hemorrhage control if active bleeding
• Compartment syndrome assessment (pain out of proportion, passive stretch pain)

Limb-Specific Assessment:

1. Neurovascular examination - document before and after any manipulation
2. Photograph wound - single high-quality photo, then cover
3. Cover with saline-soaked gauze - do not probe or explore in ED
4. Align and splint - reduces bleeding and prevents further contamination
5. Check tetanus status - administer if not up to date
6. Administer antibiotics - WITHIN 1 HOUR of presentation

Antibiotic Therapy

Antibiotic Protocol:

If penicillin allergic:

• Type I-II: Clindamycin 900mg IV q8h
• Type III: Clindamycin + aminoglycoside or aztreonam

📊 Management Algorithm

Click to expand

Management Algorithm

Immediate Actions (ED):

1. ATLS primary and secondary survey
2. Antibiotics within 1 hour
3. Tetanus prophylaxis
4. Photo-document wound then cover
5. Align and splint
6. Theatre booking

Surgical Planning:

• Type I-II: Urgent (within 24 hours)
• Type III: Same-day theatre
• Type IIIB: Early plastics consult
• Type IIIC: Immediate OR with vascular

Conservative vs Operative

Conservative management is NOT appropriate for open tibial fractures. All require:

• Surgical debridement
• Skeletal stabilization
• Definitive soft tissue coverage

Decision Points:

• Primary vs staged fixation (depends on contamination)
• Wound closure timing (primary vs delayed)
• Need for flap coverage (IIIB always requires)

Wound Management

Timing - Fix-or-Flap Principle

Timing Recommendations:

• Under 72 hours: Optimal window - lowest infection and flap failure
• 72h - 7 days: Intermediate risk - still reasonable outcomes
• Over 7 days: Increased infection, flap failure, and non-union rates

Flap Selection by Location

Flap Details

Farm Injuries

Specific considerations:

• Organic contamination (soil, manure)
• Higher bacterial loads
• Clostridium species common in soil
• More aggressive debridement required
• Consider hyperbaric oxygen if gas gangrene develops

Pediatric Open Tibial Fractures

• Classification same as adults
• Better healing potential
• Lower infection rates
• More likely to tolerate non-operative management for Type I
• Growth plate injuries may affect management

Segmental Injuries

• Automatically classified as at least Type IIIA
• Higher non-union risk
• Often need specialized fixation (IM nail with blocking screws)
• May need bone transport for bone loss

Infection

Risk factors:

• Type IIIB/C classification
• Antibiotic delay over 1 hour
• Inadequate debridement
• Delayed soft tissue coverage
• Smoking, diabetes

Management:

• Prevention is key (early antibiotics, adequate debridement)
• Culture-directed antibiotics if infection develops
• May need repeat debridement
• Consider antibiotic beads or cement spacers
• Hardware removal if infection persists

Non-union

Risk factors:

• Type III injury
• Bone loss
• Infection
• Smoking
• Inadequate fixation

Treatment options:

• Exchange nailing
• Plate augmentation
• Bone grafting (autograft, RIA)
• Masquelet technique for segmental defects
• Free vascularized fibula for massive defects

Compartment Syndrome

Amputation

Consider primary amputation if:

• Crush injury with non-viable limb (MESS score over 7)
• Prolonged warm ischemia (over 6 hours)
• Severe polytrauma where limb salvage compromises life
• Mangled extremity with no prospect of function

MESS Score: Mangled Extremity Severity Score

• Skeletal/soft tissue injury
• Limb ischemia
• Shock
• Patient age
• Score over 7 predicts amputation, but imperfect predictor

Antibiotic Duration

Type I-II:

• Continue 24-48 hours post-closure
• Can discontinue if wound closed and clean

Type III:

• Continue 72 hours or until definitive closure
• May extend if ongoing wound issues
• No benefit beyond 72h in closed wounds

Farm injuries:

• Continue penicillin for 7 days
• Higher risk of late Clostridium complications

Wound Monitoring

First 48 hours:

• Monitor for compartment syndrome (even with open wound)
• Watch for signs of infection (fever, increased pain, discharge)
• Neurovascular checks every 4 hours
• Consider second-look surgery if concern

Dressing Changes:

• NPWT changed every 48-72 hours
• Inspect wound at each change
• Document progression toward closure
• Plan definitive coverage within 72 hours

Weight-Bearing Protocol

External fixator:

• Touch weight-bearing initially
• Progress as tolerated once callus visible
• Usually 6-8 weeks to partial WB

IM nail:

• Touch to partial weight-bearing initially
• Full weight-bearing once callus bridging 3 cortices
• Usually 8-12 weeks for Type I-II, 12-16 weeks for Type III

After flap coverage:

• Non-weight-bearing for 2 weeks (flap healing)
• Then progress as per fracture stability

Rehabilitation

• Early ankle/knee ROM to prevent stiffness
• Quadriceps strengthening from day 1
• Gait training with assistive devices
• Address return to work/sport expectations early

Union Rates by Type

Infection Outcomes

Early infection (under 2 weeks):

• Usually responds to debridement and antibiotics
• May require hardware removal if persistent
• Can still achieve union with appropriate treatment

Late infection (over 6 weeks):

• More difficult to eradicate
• Often requires hardware removal
• May need chronic suppressive antibiotics
• Risk of non-union significantly increased

Functional Outcomes

Type I-II:

• Most patients return to pre-injury function
• 80-90% satisfied with outcome
• Return to work: 3-6 months average

Type IIIA:

• Good function in 70-80%
• May have some ankle/subtalar stiffness
• Return to work: 6-9 months

Type IIIB/C:

• Only 50-60% achieve good function
• High rate of chronic pain
• Return to work: 9-18 months, many with restrictions
• Amputation may give better function than poor salvage

Prognostic Factors

Favorable:

• Younger age (under 50)
• Non-smoker
• No medical comorbidities
• Early soft tissue coverage
• Adequate initial debridement

Unfavorable:

• Type IIIB/C classification
• Smoking
• Diabetes, PVD
• Delayed coverage beyond 7 days
• Bone loss over 2cm
• Infection

Long-term Considerations

• Post-traumatic arthritis in 20-30% (especially with intra-articular extension)
• Chronic pain in 30-40% of Type III
• Leg length discrepancy possible with bone loss
• Need for eventual hardware removal in 10-20%

Epidemiology

Open tibial fractures represent approximately 10-15% of all tibial fractures treated in Australian major trauma centers. Motorcycle accidents are the leading cause of high-energy open tibial fractures, reflecting Australia's high motorcycle usage rates. Rural and agricultural injuries account for a significant proportion of contaminated open fractures, necessitating awareness of Clostridial coverage protocols.

Management Considerations

Australian orthopaedic practice has widely adopted the BOAST (British Orthopaedic Association Standards for Trauma) guidelines for open fracture management. Major trauma centers operate combined ortho-plastics models, with early involvement of plastic surgery for Type IIIB injuries becoming the standard of care. The emphasis on antibiotic administration within 1 hour aligns with national antimicrobial stewardship principles.

Transfer Protocols

Patients with Type III open tibial fractures are preferentially transferred to major trauma centers with combined ortho-plastics capability. Regional centers play a crucial role in initial stabilization, antibiotic administration, and urgent debridement prior to transfer. State-based retrieval services facilitate timely transfer for definitive soft tissue coverage within the 72-hour window.

Antibiotic Access

Standard antibiotics for open fracture management (cefazolin, gentamicin, penicillin G) are readily available through PBS listings for hospital use. All are included in standard hospital formularies without requiring special authority for acute trauma indications.