Sanders CT Classification | Extensile Lateral Approach | Wound Complication Management
SANDERS CT CLASSIFICATION
Critical Must-Knows
- Sanders classification based on coronal CT through widest posterior facet
- Bohler angle under 20 degrees predicts poor outcome with conservative treatment
- Extensile lateral approach provides best exposure but 20-30% wound complications
- ORIF timing: Wait 10-21 days for swelling to resolve (wrinkle test positive)
- Primary subtalar fusion for Sanders IV in heavy laborers over 50 years
Clinical Pearls
- "Always assess for lumbar spine injury (10% concurrent with bilateral calcaneal fractures)
- "Compartment syndrome in 10% - clinical diagnosis, fasciotomy if suspected
- "ORIF benefit is selective, not universal - pragmatic UK Heel Fracture Trial (Griffin 2014) showed no overall advantage; Canadian RCT (Buckley 2002) showed benefit in younger, non-compensation patients
- "Sinus tarsi approach alternative for Sanders II - lower wound complication rate
Clinical Imaging
Imaging Gallery
Critical Calcaneal Fracture Exam Points
Classification Mastery
Sanders classification is CT-based. Type determined by number of fracture lines through posterior facet on coronal view. Type II (single line, 2 fragments) has best ORIF outcomes. Type IV (comminuted) consider primary fusion in older laborers.
Surgical Timing
Wait for swelling to resolve. ORIF performed at 10-21 days when wrinkle test positive (skin wrinkles with gentle pinch). Early surgery increases wound complications from 20% to over 40%. Document neurovascular status and soft tissue condition.
Wound Complications
20-30% wound dehiscence with extensile lateral approach. Risk factors: smoking, diabetes, obesity, swelling. Sinus tarsi approach reduces risk to under 10% but limited to Sanders II. Meticulous soft tissue handling and delayed closure critical.
Associated Injuries
10% have lumbar spine fracture (bilateral calcaneal fractures increase to 25%). Always examine spine and order imaging if bilateral. Check for compartment syndrome (10%) - clinical diagnosis based on pain out of proportion and pain with passive toe dorsiflexion.
Quick Decision Guide - Calcaneal Fracture Management
| Patient | Fracture Pattern | Treatment | Key Pearl |
|---|---|---|---|
| Any age, non-displaced | Sanders I (all subtypes) | NWB boot 6 weeks, progressive WB | Excellent outcomes with conservative care |
| Active, under 50 years | Sanders II (single fracture line) | ORIF extensile lateral at 10-21 days | Best outcomes - restoration of height and width |
| Active, any age | Sanders III (2 fracture lines) | ORIF extensile lateral at 10-21 days | Good outcomes but more challenging reduction |
| Heavy laborer, over 50 years | Sanders IV (comminuted) | Consider primary subtalar fusion | Better than delayed fusion after failed ORIF |
| Low demand, elderly | Sanders II-IV displaced | Conservative - NWB 6-8 weeks | Functional outcomes acceptable despite deformity |
Mnemonics and Memory Aids
SANDERSSanders Classification
| S | Single facet view Coronal CT through widest posterior facet |
| A | Articular split Fracture lines divide posterior facet |
| N | Number of fragments Type equals number of articular fragments |
| D | Dividing lines Type II = 1 line (2 pieces), III = 2 lines (3 pieces) |
| E | Everything shattered Type IV = comminuted, over 3 fragments |
| R | Results predict outcome Higher type = worse prognosis |
| S | Subtalar arthritis risk Type IV: 50% progress to fusion within 2 years |
| S | Single facet view Coronal CT through widest posterior facet | D | Dividing lines Type II = 1 line (2 pieces), III = 2 lines (3 pieces) | S | Subtalar arthritis risk Type IV: 50% progress to fusion within 2 years |
| A | Articular split Fracture lines divide posterior facet | E | Everything shattered Type IV = comminuted, over 3 fragments | ||
| N | Number of fragments Type equals number of articular fragments | R | Results predict outcome Higher type = worse prognosis |
Hook:SANDERS classification uses the Single view that matters - the coronal CT through the widest posterior facet - to count the Number of articular fragments!
ANGLESBohler and Gissane Angles
| A | Anterior process Forms anterior point of Bohler angle |
| N | Normal Bohler 20-40 degrees Measured on lateral radiograph |
| G | Gissane angle (Critical angle) Normally 120-145 degrees |
| L | Loss of height Bohler under 20 degrees indicates collapse |
| E | Elevation of posterior facet ORIF goal: restore Bohler to over 20 degrees |
| S | Sustentaculum preserved Medial fragment reference for reduction |
| A | Anterior process Forms anterior point of Bohler angle | G | Gissane angle (Critical angle) Normally 120-145 degrees | E | Elevation of posterior facet ORIF goal: restore Bohler to over 20 degrees |
| N | Normal Bohler 20-40 degrees Measured on lateral radiograph | L | Loss of height Bohler under 20 degrees indicates collapse | S | Sustentaculum preserved Medial fragment reference for reduction |
Hook:ANGLES guide your assessment - Normal Bohler over 20 degrees predicts Good outcomes, Loss of height (under 20) needs Elevation with surgery!
SMOKEWound Complication Risk Factors
| S | Smoking Single greatest risk factor - relative risk 3.7 |
| M | Metabolic (Diabetes) Poor wound healing, infection risk |
| O | Obesity Increases soft tissue tension and swelling |
| K | Kick injury (open) Open fractures 40-50% infection rate |
| E | Early surgery Before swelling resolves (wrinkle test negative) |
| S | Smoking Single greatest risk factor - relative risk 3.7 | K | Kick injury (open) Open fractures 40-50% infection rate |
| M | Metabolic (Diabetes) Poor wound healing, infection risk | E | Early surgery Before swelling resolves (wrinkle test negative) |
| O | Obesity Increases soft tissue tension and swelling |
Hook:SMOKE signals danger - these factors turn a 20% wound complication rate into over 50%!
SAFEExtensile Lateral Approach Layers
| S | Skin flap full-thickness L-shaped incision, avoid sharp angles |
| A | Avoid sural nerve Protect nerve at posterosuperior corner |
| F | Flap elevation subperiosteally Leave periosteum on bone, dissect as one layer |
| E | Expose from calcaneocuboid to posterior tuberosity Complete lateral wall visualization |
| S | Skin flap full-thickness L-shaped incision, avoid sharp angles | F | Flap elevation subperiosteally Leave periosteum on bone, dissect as one layer |
| A | Avoid sural nerve Protect nerve at posterosuperior corner | E | Expose from calcaneocuboid to posterior tuberosity Complete lateral wall visualization |
Hook:Keep it SAFE - elevate the lateral wall as a single full-thickness flap to protect blood supply!
Overview and Epidemiology
Clinical Significance
Calcaneal fractures are devastating injuries occurring primarily in working-age males (mean age 35-45 years) from high-energy axial loading (falls from height, motor vehicle accidents). The injury mechanism - axial load driving talus into calcaneus - produces a predictable fracture pattern with the sustentaculum tali remaining attached to talus while lateral and posterior fragments displace. Outcomes depend on articular involvement, age, occupation, and achieving anatomical reduction of posterior facet.
Mechanism and Demographics
- Peak age: 30-50 years (working population)
- Male predominance: 75-80% of cases
- Fall from height: 60-70% (over 2 meters)
- Motor vehicle accident: 20-25%
- Other trauma: 10-15% (industrial, crush)
Most fractures occur in manual laborers and construction workers.
Clinical Impact
- Work disability: 30-40% never return to previous employment
- Subtalar arthritis: 50-70% by 2 years (Sanders III-IV)
- Persistent pain: 40-60% at 2 years despite treatment
- Healthcare cost: Over 75,000 AUD average per patient
- Bilateral fractures: 10% overall, 25% with lumbar spine injury
Economic impact includes lost productivity and long-term disability.
Pathophysiology and Mechanisms
Critical Anatomy - Sustentaculum Tali
The sustentaculum tali is the key to understanding calcaneal fracture patterns. This medial process remains attached to the talus via strong interosseous talocalcaneal ligament and deltoid ligament complex. During injury, the sustentaculum acts as a hinge - the primary fracture line runs lateral to it (primary fracture line of Sanders), and all other fragments displace relative to this stable medial fragment. This anatomical constant guides reduction - reduce all fragments to the sustentaculum fragment.
Key Anatomical Structures and Clinical Relevance
| Structure | Anatomical Detail | Fracture Relevance | Surgical Pearl |
|---|---|---|---|
| Posterior facet | Largest articular surface, bears 80% weight | Fracture disruption causes subtalar arthritis | Must restore to within 2mm step-off for good outcome |
| Sustentaculum tali | Medial shelf, supports talar head | Remains attached to talus - stable reference | Reduce all fragments to sustentaculum position |
| Lateral wall | Forms lateral border, thin cortex | Blowout fragment causes widening | Restore height and width to prevent impingement |
| Anterior process | Articulates with cuboid | Separate injury (avulsion), not Sanders classification | If isolated, treat conservatively |
| Calcaneal canal | Neurovascular bundle passage | Risk of tarsal tunnel syndrome (5-10%) | Decompress if acute compartment syndrome |
Classification Systems
Sanders Classification (1993)
The gold standard classification for intra-articular calcaneal fractures, based on coronal CT through the widest portion of the posterior facet. Classification determines treatment and predicts outcomes.
Classification Technique
Sanders classification is performed on coronal CT slice through widest posterior facet. Identify sustentaculum tali (medial, constant fragment). Count fracture lines from lateral to medial: A (lateral third), B (central third), C (medial third between central and sustentaculum). Subtypes based on which lines present: IIA (A only), IIB (B only), IIC (C only), IIIABC (all three lines present).
Clinical Assessment and Radiographic Evaluation
History
Mechanism:
- Fall from height (most common)
- Motor vehicle accident (dashboard injury)
- Industrial crush injury
Key questions:
- Height of fall (energy assessment)
- Bilateral injury? (always examine both feet)
- Back pain? (10% lumbar fracture with bilateral)
- Timing of injury (swelling progression)
- Medical comorbidities (diabetes, smoking, PVD)
- Occupation (manual labor affects treatment choice)
Examination
Inspection:
- Swelling and ecchymosis (lateral and plantar)
- Heel widening (compare to contralateral)
- Loss of normal heel contour
- Skin integrity (open fractures 5-10%)
- Fracture blisters (delay surgery)
Palpation:
- Tenderness over calcaneus
- Palpable step-off lateral wall
- Compartment assessment (firm, tense)
Neurovascular:
- Dorsalis pedis and posterior tibial pulses
- Sensation (tibial, sural, superficial peroneal)
- Pain with passive toe dorsiflexion (compartment syndrome)
Compartment Syndrome Recognition
10% of calcaneal fractures develop compartment syndrome. This is a clinical diagnosis - do not wait for pressure measurements. Key signs: pain out of proportion to injury, pain with passive toe dorsiflexion (stretches deep flexors), tense swollen foot. Presence of pulses does NOT exclude compartment syndrome. If suspected: urgent fasciotomy of all 9 foot compartments. Delayed diagnosis leads to clawing, contractures, and chronic pain.
Differential Diagnosis of Acute Hindfoot Pain after Axial Load
| Diagnosis | Distinguishing features | Key investigation | Why it matters |
|---|---|---|---|
| Intra-articular calcaneal fracture | Heel widening, plantar/lateral bruising, reduced Bohler angle, posterior facet involvement | Lateral/axial X-ray then fine-cut CT (Sanders classification) | Index diagnosis - drives operative vs non-operative decision |
| Extra-articular calcaneal fracture (anterior process, tuberosity, sustentaculum) | Localised tenderness, posterior facet spared, often lower-energy or avulsion | X-ray and CT; oblique views for anterior process | Usually managed non-operatively; not Sanders-classified |
| Talar fracture (body/neck) or peritalar dislocation | Pain anterior to calcaneus, deformity, talar dome tenderness | CT - high rate of associated injury and AVN risk | Different fixation and AVN counselling; commonly coexists |
| Calcaneal stress/insufficiency fracture | Insidious onset, low energy or repetitive load, positive squeeze test | MRI (marrow oedema) when X-ray normal | Non-operative; missing it delays diagnosis in athletes/elderly |
| Severe ankle sprain / lateral ligament injury | Tenderness over ATFL, no bony point tenderness, intact Bohler angle | X-ray to exclude fracture (Ottawa rules) | Avoid mislabelling an occult fracture as a sprain |
| Achilles tendon avulsion / tuberosity avulsion fracture | Palpable gap or bony fragment, weak plantarflexion, skin at risk posteriorly | Lateral X-ray; assess overlying skin urgently | Tuberosity avulsion threatens skin - may need urgent fixation |
Investigations
Plain Radiographs (Initial)
Essential views:
- Lateral foot: Assess Bohler angle (normal 20-40 degrees) and Gissane angle (normal 120-145 degrees)
- Axial (Harris view): Assess varus/valgus angulation and calcaneal width
- AP and oblique foot: Evaluate anterior process and calcaneocuboid joint involvement
Measurements:
- Bohler angle under 20 degrees predicts poor outcome
- Compare calcaneal height and width to contralateral side
CT Scan (Gold Standard)
Protocol:
- Fine-cut (1-2mm) slices with coronal, sagittal, and axial reconstructions
- Coronal view through widest posterior facet is critical for Sanders classification
- 3D reconstruction helpful for surgical planning (not for classification)
Assessment:
- Sanders type and subtype determination
- Fracture line location and number of fragments
- Posterior facet step-off and displacement
- Lateral wall comminution and widening
- Calcaneocuboid joint involvement
Imaging Investigation Protocol
| Investigation | Timing | Purpose | Key Information |
|---|---|---|---|
| Plain radiographs (lateral, axial, AP, oblique) | Emergency Department (initial) | Confirm fracture, assess displacement, measure angles | Bohler angle, Gissane angle, calcaneal height/width, open fracture |
| CT scan (1-2mm slices, multiplanar) | Within 24-48 hours of presentation | Sanders classification, surgical planning, assess comminution | Sanders type, posterior facet fragments, lateral wall integrity, calcaneocuboid joint |
| Lumbar spine X-ray or CT | If bilateral calcaneal fractures or back pain | Rule out associated lumbar fracture (10-25% incidence) | L1-L2 compression fracture most common (axial loading mechanism) |
| MRI | Rarely indicated | Occult fracture, stress fracture, ligament injury assessment | Useful if high clinical suspicion with negative X-ray, or for suspected bifurcate ligament injury |
Management Algorithm
Non-Operative Treatment
Indications:
- Sanders Type I (non-displaced)
- Extra-articular fractures (anterior process, sustentaculum, body)
- Sanders IV elderly or low-demand patients
- Severe medical comorbidities precluding surgery
- Patient preference after informed consent
Conservative Protocol
- Non-weight bearing in CAM boot or short leg cast
- Elevate leg above heart level 23 hours/day first 2 weeks
- Ice therapy and compression
- Early ankle ROM exercises (plantarflexion/dorsiflexion)
- DVT prophylaxis (LMWH if immobilized, high-risk)
- Monitor for compartment syndrome first 48 hours
- Start protected weight bearing at 6 weeks
- Progress from partial (20kg) to full WB over 4 weeks
- Continue boot until 12 weeks
- Subtalar ROM exercises
- Gait re-education (avoid antalgic patterns)
- Full weight bearing in supportive footwear
- Heel cup or orthotic for persistent heel pain
- Gradual return to activities
- Consider subtalar fusion if persistent pain over 1 year
Understanding these conservative options helps guide treatment selection.
Conservative Outcomes
Sanders Type I: 85-90% good outcomes with conservative care. Sanders II-III displaced: 50-60% good outcomes (inferior to ORIF). Sanders IV: 40-50% good outcomes, similar to ORIF - conservative reasonable choice for low-demand elderly. Key prognostic factor: Bohler angle under 0 degrees predicts poor outcome regardless of treatment.
Surgical Technique - ORIF via Extensile Lateral Approach
Alternative Fixation Techniques
Pre-operative Assessment and Planning
Timing Considerations
Optimal timing: 10-21 days post-injury
Reasons for delay:
- Allow soft tissue swelling to resolve
- Wrinkle test positive (skin wrinkles with gentle pinch)
- Fracture blisters to epithelialize
- Patient optimization (smoking cessation, glucose control)
Early surgery (under 7 days): 40-50% wound complication rate
Delayed surgery (over 3 weeks): Fracture fragment malunion, difficult reduction
Consent Points
Key risks to discuss:
- Wound complications: 20-30% (dehiscence, necrosis)
- Infection: 5-10% superficial, 2-5% deep
- Sural nerve injury: 5-10% (numbness lateral foot)
- Hardware prominence: 10-15% (may require removal)
- Subtalar arthritis: 30-50% by 5 years (disease, not surgery)
- Need for subtalar fusion: 15-25% within 5 years
- DVT/PE: 2-5% (prophylaxis given)
- Chronic pain: 30-40% despite anatomical reduction
Pre-operative Checklist
- Smoking cessation (minimum 4 weeks ideal, 2 weeks acceptable)
- Diabetic control (HbA1c under 8%)
- Nutrition optimization (albumin over 3.5)
- Weight loss if obese (BMI over 35 high risk)
- Review CT to template plate size and screw lengths
- Standard: Lateral calcaneal locking plate (7-9 holes)
- Screws: 3.5mm cortical and locking, 35-50mm lengths
- K-wires: 1.6mm and 2.0mm for provisional fixation
- Consider calcium phosphate bone void filler for voids
- C-arm fluoroscopy (confirm positioning before draping)
- Lamina spreaders or Schantz pins for distraction
- Dental picks or curettes for fracture debris removal
- Self-retaining retractors (avoid excessive tension)
- Headlight or surgical loupe magnification
Ensuring proper equipment facilitates successful reduction.
Wrinkle Test
The wrinkle test determines surgical timing. Gently pinch lateral skin over fracture site - if skin wrinkles, swelling has resolved sufficiently for surgery. If skin remains tense and shiny (negative wrinkle test), delay surgery. Operating on swollen tissue increases wound complication rate from 20% to over 40%. No specific number of days - assess clinical swelling.
Complications
Complications of Calcaneal Fractures and ORIF
| Complication | Incidence | Risk Factors | Management |
|---|---|---|---|
| Wound dehiscence/necrosis | 20-30% (ORIF), 0% (conservative) | Smoking, diabetes, obesity, early surgery (under 10 days), extensile approach | Local wound care, negative pressure therapy, delayed closure, skin graft if needed, flap rarely |
| Infection (superficial) | 5-10% | Wound dehiscence, diabetes, immunosuppression, obesity | Oral antibiotics, wound care, remove superficial sutures, allow drainage |
| Deep infection / osteomyelitis | 2-5% | Open fracture, wound dehiscence, diabetes, smoking | IV antibiotics, surgical debridement, retain hardware if stable, remove if loose, bone culture |
| Sural nerve injury | 5-10% | Extensile lateral approach, excessive retraction, direct laceration | Numbness lateral foot - usually well-tolerated, no treatment, neuropathic pain rare |
| Compartment syndrome | 10% (acute injury) | High-energy injury, crush mechanism, swelling, vascular injury | Urgent fasciotomy all 9 compartments (medial, lateral, superficial/deep central, interosseous ×4) |
| Subtalar arthritis | 30-50% by 5 years (all treatments) | Sanders III-IV, step-off over 2mm, high-energy injury, age over 50 | Conservative initially (NSAIDs, injections), subtalar fusion if persistent pain limiting function |
| Peroneal tendonitis / impingement | 10-15% | Lateral wall widening, hardware prominence, fibular impingement | Conservative (NSAIDs, physio), hardware removal if prominent, lateral wall decompression osteotomy |
| Hardware prominence | 10-15% | Thin soft tissue, prominent plate, weight gain post-op | Observation if asymptomatic, hardware removal after 12 months if symptomatic (fracture healed) |
| Malunion (loss of height/width) | 15-25% (conservative), 5-10% (ORIF) | Inadequate reduction, loss of fixation, non-compliance NWB | Salvage options: corrective osteotomy, subtalar fusion, triple arthrodesis |
| Chronic pain syndrome | 30-40% (all treatments) | High-energy injury, Sanders IV, depression/anxiety, litigation | Multidisciplinary pain management, psychological support, avoid repeat surgery unless clear indication |
Postoperative Care and Rehabilitation
Post-ORIF Rehabilitation Timeline
- Elevation: Leg above heart level continuously (pillows, CPM device)
- Ice: 20 minutes on, 40 minutes off around dressing
- NWB: Strict non-weight bearing, crutches or knee walker
- Pain control: Multimodal (paracetamol, NSAID, opioid prn)
- DVT prophylaxis: LMWH (enoxaparin 40mg daily) or DOAC
- Wound check: 48 hours (remove drain if present, mark ecchymosis)
- Discharge: When pain controlled, mobile NWB, safe at home
- NWB continues: 6 weeks minimum (fracture healing)
- Splint: Backslab first 2 weeks, then CAM boot (allows removal for hygiene)
- Wound check: Week 2 (assess healing, watch dehiscence), Week 3-4 (suture removal - delayed healing expected)
- Elevation: Continue elevating leg when seated (above heart level 6-8 hours/day)
- Ankle ROM: Gentle active plantarflexion/dorsiflexion in boot (avoid inversion/eversion)
- X-rays: 6 weeks (check hardware, no loss of reduction)
- DVT prophylaxis: Continue until mobile or 6 weeks
- Start PWB: 20-30kg (toe-touch) in boot at 6 weeks if X-ray shows healing
- Progress WB: Increase 10-20kg every 1-2 weeks based on pain tolerance
- FWB target: 10-12 weeks
- Boot weaning: Transition to supportive shoe with heel cup (12 weeks)
- Physical therapy: Gait re-education, subtalar/ankle ROM, strengthening (intrinsics, gastrocnemius)
- Swelling: Expect significant swelling with WB (compression sock, continue elevation when seated)
- Footwear: Supportive shoes with cushioned heel (avoid flat shoes, high heels)
- Orthotic: Custom orthotic or heel cup for persistent heel pain
- Activity progression: Walking → incline → stairs → jogging (if desired and pain-free)
- Work: Light duty 3-4 months, heavy labor 6-9 months
- Sport: Low-impact (cycling, swimming) 4-6 months, high-impact (running) 9-12 months
- Hardware removal: Consider if prominent and symptomatic after 12 months (fracture healed)
- Follow-up: 6 months, 1 year, then annually or prn
- X-rays: Annual for first 2 years (assess subtalar arthritis)
- Subtalar fusion: If progressive arthritis with pain limiting function (15-25% by 5 years)
- Chronic pain: Multidisciplinary if persists (pain clinic, psychology, physio)
- Realistic expectations: 30-40% have some persistent pain despite anatomical reduction
Long-term surveillance identifies late complications requiring intervention.
Weight Bearing Progression
NWB for minimum 6 weeks is mandatory - calcaneal bone is cancellous and slow to heal. Early weight bearing (before 6 weeks) risks loss of reduction and fixation failure. PWB starts at 6 weeks only if X-ray shows early healing (fracture lines blurring). Progress slowly - aggressive WB causes swelling, pain, and potential secondary displacement. Many patients take 12-16 weeks to achieve comfortable FWB. Set expectations early.
Outcomes and Prognosis
Prognostic Factors for Calcaneal Fracture Outcomes
| Factor | Good Prognosis | Poor Prognosis | Impact |
|---|---|---|---|
| Sanders Type | Type I or II | Type IV | Type predicts outcome regardless of treatment |
| Age | Under 40 years | Over 60 years | Younger patients tolerate residual stiffness better |
| Occupation | Sedentary, light manual | Heavy laborer, prolonged standing | Heavy labor 60% cannot return to same job |
| Articular reduction (ORIF) | Step-off under 2mm | Step-off over 2mm | Over 2mm step-off: 2x increased arthritis rate |
| Bohler angle restoration | Restored to over 20 degrees | Remains under 15 degrees | Under 15 degrees: 3x worse functional score |
| Bilateral fractures | Unilateral | Bilateral | Bilateral: 50% worse function, disability higher |
| Workers compensation/litigation | No claim | Active claim | Compensation claim: 2x worse outcome scores |
Realistic Outcome Expectations
Counsel patients realistically: Even with perfect ORIF of Sanders II, 20-25% will have suboptimal outcomes. Sanders IV has poor outcomes regardless of treatment (40-50% good results with ORIF or conservative). Subtalar arthritis develops in 30-50% by 5 years (reflects injury severity, not treatment failure). Heavy laborers: Only 40-60% return to same occupation. Set expectations early to avoid dissatisfaction and chronic pain syndrome.
Evidence Base and Key Trials
UK Heel Fracture Trial - Operative vs Non-Operative for Displaced Intra-Articular Calcaneal Fractures
- Pragmatic, assessor-blinded multicentre RCT (22 UK hospitals): 151 patients with closed displaced intra-articular fractures randomised to ORIF (n=73) or non-operative care (n=78)
- Primary outcome was the Kerr-Atkins pain/function score at 2 years (not SF-36): 69.8 (operative) vs 65.7 (non-operative), adjusted 95% CI of difference -7.1 to 7.0 - no significant difference
- No significant difference in any secondary outcome (AOFAS hindfoot, SF-36, EQ-5D, walking speed, gait symmetry)
- Complications and reoperations were markedly MORE common after surgery (odds ratio 7.5, 95% CI 2.0 to 41.8)
- Authors concluded ORIF is NOT recommended for typical displaced intra-articular calcaneal fractures
Exam Viva Scenarios
Use these scenarios to practise clinical reasoning and management decisions
Scenario 1: Sanders Classification and Initial Management (Standard, 2-3 min)
"A 42-year-old builder presents after falling 3 meters from scaffolding, landing on both feet. He has bilateral heel pain and swelling. X-rays show bilateral calcaneal fractures with loss of Bohler angles. You order CT scans. The right calcaneus shows a single fracture line through the posterior facet on the coronal view (Sanders IIB), and the left shows two fracture lines with three articular fragments (Sanders IIIAB). How do you manage this patient?"
Scenario 2: ORIF Surgical Technique - Extensile Lateral Approach (Challenging, 3-4 min)
"You are performing ORIF for a Sanders Type IIA calcaneal fracture in a 38-year-old patient. Walk me through your surgical approach and reduction technique. The examiner hands you a model calcaneus and asks you to describe the key steps."
Scenario 3: Post-operative Wound Dehiscence Management (Critical, 2-3 min)
"You performed ORIF via extensile lateral approach for a Sanders IIB calcaneal fracture 2 weeks ago. The patient returns with 3cm wound dehiscence over the lateral incision, exposing the plate but no purulence. The patient is a smoker and diabetic (HbA1c 8.5%). How do you manage this complication?"
MCQ Practice Points
Sanders Classification Question
Q: On which imaging view is the Sanders classification of calcaneal fractures determined?
A: Coronal CT through the widest portion of the posterior facet of the calcaneus. The classification is based on the number of articular fragments created by fracture lines on this single critical coronal slice. Type I = non-displaced (any number of lines), Type II = 1 fracture line (2 fragments), Type III = 2 fracture lines (3 fragments), Type IV = comminuted (over 3 fragments). Subtypes (IIA, IIB, IIC, etc.) based on which fracture lines (A=lateral, B=central, C=medial) are present.
Bohler Angle Question
Q: What is the normal range for Bohler angle, and what value predicts poor outcome with conservative management?
A: Normal Bohler angle is 20-40 degrees (typically 30-35 degrees). Measured on lateral foot radiograph as the angle formed by: (1) line from posterior superior calcaneus to highest point of posterior facet, intersecting (2) line from highest point of posterior facet to anterior process. Bohler angle under 20 degrees (especially under 10 degrees) predicts poor functional outcome with conservative management, indicating significant loss of calcaneal height. ORIF goal is restoration to over 20 degrees minimum.
ORIF Timing Question
Q: What is the optimal timing for ORIF of calcaneal fractures and why?
A: Optimal timing is 10-21 days post-injury. Rationale: Allow soft tissue swelling to resolve to minimize wound complications (20-30% rate, increases to 40-50% if surgery under 7 days). The wrinkle test determines readiness - gently pinch lateral skin; if wrinkles form, swelling resolved and safe to operate. Early surgery (under 7 days) has double the wound complication rate. Delayed surgery (over 3 weeks) makes reduction more difficult due to early fracture healing and fibrous tissue formation. The window of 10-21 days balances wound healing risk against ease of reduction.
Compartment Syndrome Question
Q: What is the incidence of compartment syndrome with calcaneal fractures and how is it diagnosed?
A: 10% of calcaneal fractures develop acute compartment syndrome - highest rate of any foot injury. This is a clinical diagnosis based on: (1) Pain out of proportion to injury, (2) Pain with passive toe dorsiflexion (stretches deep flexor muscles in deep compartments), (3) Tense, swollen foot. Key point: pulses are usually present (compartment syndrome is increased pressure in fascial compartments, not arterial occlusion). Do not delay for pressure measurements if clinically suspected. Treatment: urgent fasciotomy of all 9 foot compartments (medial, lateral, superficial central, deep central, 4 interosseous, calcaneal). Delay over 6 hours causes irreversible muscle necrosis leading to clawing, contractures, chronic pain.
Landmark RCT Question
Q: What did the two major RCTs (Griffin/UK Heel Fracture Trial and Buckley/Canadian trial) show for ORIF vs non-operative treatment of displaced calcaneal fractures?
A: The UK Heel Fracture Trial (Griffin et al, BMJ 2014, PMID 25059747) was a pragmatic multicentre RCT of 151 patients. The primary outcome was the Kerr-Atkins score at 2 years (69.8 operative vs 65.7 non-operative, 95% CI of difference -7.1 to 7.0) - no significant difference, with higher complications/reoperations after surgery (OR 7.5), leading the authors to conclude ORIF is not recommended for typical displaced fractures. The earlier Canadian RCT (Buckley et al, JBJS Am 2002, PMID 12377902) of 424 patients found overall equivalence (SF-36 64.7 vs 68.7, p=0.13) but, after excluding Workers' Compensation patients, identified subgroups that benefited from surgery - younger patients, women, light-workload patients, moderately reduced Bohler angle (0-14 degrees), and anatomically reducible fractures (step-off 2 mm or less). Clinical implication: surgery should be selective, targeting younger, non-compensation patients with reducible fractures, rather than offered routinely. (Note: "ORCA" is an informal label sometimes applied to these trials; cite the named trials and authors in the exam.)
Primary Fusion Question
Q: In which patients should primary subtalar fusion be considered instead of ORIF for calcaneal fractures?
A: Primary subtalar fusion indications: (1) Sanders Type IV fractures in heavy laborers over 50 years, (2) Severe comminution precluding stable fixation, (3) Pre-existing subtalar arthritis. Rationale: Sanders IV fractures have poor outcomes with any treatment and a high rate of progression to subtalar arthritis requiring late fusion. Primary fusion (ORIF + primary subtalar arthrodesis) aims to achieve the definitive endpoint in one operation and pre-empt a secondary procedure. Evidence: the only RCT in this area (Buckley/Canadian Orthopaedic Trauma Society, J Orthop Trauma 2014, PMID 24983433) randomised 31 Sanders IV fractures and found no statistically significant difference between ORIF alone and ORIF + primary subtalar arthrodesis (SF-36 PCS 30.2 vs 37.8, p=0.10), but noted primary fusion may speed recovery and avoid late secondary fusion. Consider especially in heavy labourers in whom subtalar arthritis is near-inevitable.
Guidelines, Registries & Global Practice
Global Epidemiology
Calcaneal Fracture - Global Epidemiology (PubMed-verified)
| Parameter | Figure | Source |
|---|---|---|
| Share of all tarsal fractures | Calcaneus is the most commonly fractured tarsal bone; ~60-75% are intra-articular | Sanders R 1993 (PMID 8472475) and standard texts |
| Demographics and mechanism | Predominantly working-age men injured by axial loading (fall from height / road trauma) | Tennent TD 2001 two-centre series (PMID 11476816): 76% male, 88% falls from height |
| Long-term disability | Significantly lower health-related quality of life than population norms; chronic disability common, though ~85% return to some work | Alexandridis G, Injury 2016 (PMID 27156040) |
| Late subtalar fusion - high-risk group | Male Workers' Compensation heavy labourers with Bohler angle under 0 degrees and Sanders IV are at greatly increased risk of secondary fusion | Csizy M / Buckley R, J Orthop Trauma 2003 (PMID 12571499) |
Guideline & Practice Comparison Across Systems
How Major Systems Approach Displaced Intra-Articular Calcaneal Fractures
| Body / region | Stance on routine ORIF | Evidence basis | Level |
|---|---|---|---|
| UK / BOA-BOFAS practice (post UK Heel Fracture Trial) | Routine ORIF not recommended for typical displaced fractures; selective surgery for specific patterns | Griffin BMJ 2014 pragmatic RCT (PMID 25059747) | Level 1 |
| North American (AAOS / OTA, Canadian) practice | Selective ORIF favoured - benefit concentrated in younger, non-compensation, anatomically reducible fractures | Buckley JBJS Am 2002 RCT (PMID 12377902) | Level 1 |
| AO Foundation principles | Anatomic restoration of posterior facet, Bohler/Gissane angles, height and width when operating; increasing use of minimally invasive sinus tarsi exposure | Bai OTSR 2018 meta-analysis (PMID 29410159) | Level 2 |
| European (EFORT / German-speaking) practice | Active operative tradition (Zwipp/Rammelt); CT-based planning, with primary subtalar fusion considered for non-reconstructable Sanders IV | Buckley/COTS RCT, J Orthop Trauma 2014 (PMID 24983433) | Level 2 |
Registry & Practice-Variation Note
There is no dedicated international calcaneal-fracture implant registry comparable to arthroplasty registries (AOANJRR/NJR/AJRR), because fixation uses generic trauma plates and screws rather than tracked implants. Evidence therefore rests on RCTs and meta-analyses rather than registry data. Practice varies widely: the pragmatic UK trial pushed many UK units toward non-operative management, whereas North American and continental European centres maintain a more operative, anatomic-reduction philosophy with growing adoption of minimally invasive approaches. In the exam, defend your plan from the trial evidence and the individual patient (age, occupation, compensation status, soft tissues, fracture pattern) rather than from a single national guideline.
Australian Context
Australian Epidemiology & Access to Care
Calcaneal fractures in Australia predominantly affect working-age men injured in falls from height (notably construction) and road trauma, mirroring the international pattern (male predominance and high-energy axial loading documented by Tennent 2001, PMID 11476816). A large proportion present through workers' compensation pathways, which - as the Canadian RCT data show (Buckley 2002, PMID 12377902; Csizy 2003, PMID 12571499) - is itself associated with poorer functional outcomes and a higher rate of late subtalar fusion.
Definitive care is concentrated in trauma centres with foot-and-ankle and orthopaedic-trauma expertise, reflecting the wound-complication risk of the extensile approach. Rural and remote patients are typically transferred for CT planning and surgical timing once soft tissues settle, and the long non-weight-bearing rehabilitation carries a substantial productivity and disability burden consistent with the reduced quality-of-life findings of Alexandridis 2016 (PMID 27156040).
Australian Guidelines & Standards
VTE prophylaxis (immobilised lower-limb fracture): pharmacological prophylaxis (LMWH such as enoxaparin 40 mg daily, or a DOAC) is standard, continued until the patient is mobile, with extended duration for higher-risk patients, in line with national safety-and-quality standards.
Antibiotic prophylaxis for ORIF (per Therapeutic Guidelines): cefazolin 2 g IV at induction; for severe penicillin allergy, substitute a glycopeptide (e.g. vancomycin) per local protocol; re-dose for prolonged surgery or major blood loss.
Smoking cessation is a modifiable wound-risk factor and should be actively supported (Quitline 13 7848) before elective ORIF.
(Doses follow current Therapeutic Guidelines; verify against the local formulary at the time of use.)
Medicolegal Documentation Requirements
Critical documentation for calcaneal fracture management:
Consent discussion (must document):
- Wound complication risk 20-30% (higher with smoking, diabetes)
- Infection risk 5-10%
- Nerve injury (sural nerve) 5-10%
- Subtalar arthritis 30-50% by 5 years (disease progression, not surgical failure)
- Need for future subtalar fusion 15-25%
- Alternative treatments discussed (conservative, primary fusion)
- Realistic return to work expectations (40-60% return to heavy labor)
Operative documentation (critical details):
- Pre-operative soft tissue assessment (wrinkle test positive, no fracture blisters)
- Fluoroscopy-confirmed reduction (Bohler angle, step-off measurement)
- Hardware used (plate type, screw sizes and positions)
- Intra-operative complications and management
- Estimated blood loss, tourniquet time
- Post-operative instructions (NWB duration, elevation, wound check timing)
Common litigation issues:
- Wound complications not consented - patients surprised by dehiscence
- Compartment syndrome missed - delayed fasciotomy with permanent damage
- Operating too early - swelling present, wound breakdown blamed on timing
- Poor functional outcome - patient expected return to normal (unrealistic expectations)
Protection: Document detailed consent, realistic outcome discussion, appropriate timing (wrinkle test), and compartment syndrome surveillance in first 48 hours.
Calcaneal Fractures
Clinical summary
Key Anatomy
- •Posterior facet = 80% weight bearing surface, articular with talus
- •Sustentaculum tali = medial shelf, attached to talus (stable reference for reduction)
- •Bohler angle = 20-40 degrees normal, under 20 degrees poor outcome
- •Gissane angle (critical angle) = 120-145 degrees normal
- •Sural nerve = 1-2cm posterior to fibula, at risk in extensile lateral approach
- •Lateral calcaneal artery = from peroneal, supplies lateral wall and skin
Sanders Classification (CT Coronal View)
- •Type I = Non-displaced (any lines), conservative, 85-90% good outcomes
- •Type II = 1 fracture line, 2 fragments (IIA lateral, IIB central, IIC medial), ORIF, 75-85% good outcomes
- •Type III = 2 fracture lines, 3 fragments (AB, AC, BC, ABC), ORIF, 60-70% good outcomes
- •Type IV = Comminuted over 3 fragments, conservative or primary fusion, 40-50% good outcomes
- •Coronal slice through WIDEST posterior facet used for classification
Treatment Algorithm
- •Sanders I → Conservative (NWB 6 weeks, boot)
- •Sanders II-III active under 60 years → ORIF extensile lateral at 10-21 days
- •Sanders II simple pattern → Consider sinus tarsi approach (lower wound complications)
- •Sanders IV heavy laborer over 50 years → Primary subtalar fusion
- •Sanders IV elderly low-demand → Conservative
- •ORIF timing = 10-21 days (wrinkle test positive), early surgery doubles wound complications
ORIF Surgical Pearls
- •Extensile lateral approach: L-shaped incision, full-thickness flap (no undermining)
- •Protect sural nerve (1cm below fibula tip with horizontal limb)
- •Reduction sequence: (1) Height (distraction), (2) Posterior facet to sustentaculum, (3) Width
- •Goal: Bohler angle over 20 degrees, step-off under 2mm
- •Key fixation: Screws from lateral plate to sustentaculum medially (40-50mm locking)
- •Closure: Meticulous, no tension, drain 24-48h, strict elevation post-op
Complications
- •Wound dehiscence = 20-30% (ORIF), higher with smoking/diabetes/obesity/early surgery
- •Compartment syndrome = 10%, clinical diagnosis, pain with passive toe dorsiflexion, urgent fasciotomy 9 compartments
- •Sural nerve injury = 5-10%, lateral foot numbness
- •Subtalar arthritis = 30-50% by 5 years (disease, not treatment failure), 15-25% need fusion
- •Infection = 5-10% superficial, 2-5% deep
- •Chronic pain = 30-40% despite anatomical reduction