High-yield overview
Medial Column Keystone | AVN Risk | Sangeorzan Classification | Athletes at Risk
47%Avulsion fractures (most common)
25%AVN rate in body fractures
86%Union rate with early treatment
6-8 wksNon-weight-bearing for stress fractures
SANGEORZAN CLASSIFICATION (BODY FRACTURES)
Type 1
PatternCoronal fracture, dorsal fragment, no forefoot angulation
TreatmentORIF if displaced greater than 1mm or unstable
Type 2
PatternDorsomedial to plantar-lateral, forefoot displacement
TreatmentORIF - restore medial column length
Type 3
PatternComminuted, central or lateral fragmentation
TreatmentORIF with possible bone grafting
Critical Must-Knows
- Precarious blood supply - central third is watershed zone (AVN risk)
- CT scan essential for body fractures - assess articular displacement
- Stress fractures - often missed initially, high index of suspicion in athletes
- Medial column length must be restored - avoid shortening
- 6-8 weeks non-weight-bearing minimum for stress fractures
Clinical Pearls
- "Blood supply: dorsal and plantar arteries, central zone relatively avascular
- "Sangeorzan Type 2 most common body fracture pattern
- "Stress fractures: central third, sagittal orientation, bone scan/MRI to diagnose
- "Associated injuries: cuboid, cuneiforms, tarsometatarsal joint
- "Malunion leads to planovalgus deformity and midfoot arthritis
Viva Danger Zones
Classic Viva Scenarios:
- High-energy midfoot trauma - systematic assessment of Chopart/Lisfranc complex
- Athlete with vague midfoot pain - navicular stress fracture until proven otherwise
- Displaced navicular body fracture - surgical approach and fixation options
- Post-operative AVN - recognition and salvage options
- Malunion with planovalgus - reconstructive options
Never Say:
- "X-rays are sufficient for surgical planning"
- "Weight-bear as tolerated for stress fractures"
- "Accept any displacement of navicular body fractures"
- "The navicular has good blood supply like other tarsal bones"
At a Glance Table
Navicular Fracture Types: Quick Reference
| Feature | Avulsion | Body | Stress | Tuberosity |
|---|---|---|---|---|
| Frequency | 47% (most common) | 26% | 3% | 24% |
| Mechanism | Capsule avulsion | High-energy axial load | Repetitive loading | PTT avulsion/direct trauma |
| Typical Patient | Any age, low energy | 20-40 years, trauma | Athletes (track/basketball) | Older patients or trauma |
| Key Imaging | X-rays sufficient | CT essential for planning | MRI gold standard | X-rays, CT if large |
| Treatment | Conservative if small | ORIF if displaced over 1mm | NWB 6-8 weeks | ORIF if large/displaced |
| AVN Risk | Very low | 25% (high) | Variable (central worse) | Low |
| Nonunion Risk | Rare | Moderate | High (central location) | Low |
| Return to Activity | 6-8 weeks | 4-6 months | 4-6 months | 8-12 weeks |
| Prognosis | Excellent | Good-Fair (type dependent) | Good if early treatment | Good |
Mnemonic
NAVICULAR
Key Features of Navicular Fractures
| N | No good blood supply to central third AVN risk |
| A | Athletes at risk for stress fractures |
| V | Very important for medial arch keystone |
| I | Imaging with CT essential for body fractures |
| C | Classification Sangeorzan for body fractures |
| U | Union problematic in central stress fractures |
| L | Length of medial column must be maintained |
| A | Avulsion fractures most common 47% |
| R | Rest and non-weight-bearing for stress fractures |
| N | No good blood supply to central third AVN risk | I | Imaging with CT essential for body fractures | L | Length of medial column must be maintained |
| A | Athletes at risk for stress fractures | C | Classification Sangeorzan for body fractures | A | Avulsion fractures most common 47% |
| V | Very important for medial arch keystone | U | Union problematic in central stress fractures | R | Rest and non-weight-bearing for stress fractures |
Hook:The NAVICULAR is critical for arch support but has fragile blood supply
Mnemonic
SANGEORZAN
Body Fracture Classification
| S | Single fragment dorsally Type 1 (coronal plane) |
| A | Angulation of forefoot (dorsomedial-plantarlateral) Type 2 |
| N | Numerous fragments (comminuted) Type 3 |
| G | Greater displacement = higher type = worse prognosis |
| E | Each type increases AVN and nonunion risk |
| O | ORIF indicated for all displaced body fractures |
| R | Restore medial column alignment |
| Z | Zone of comminution affects outcome |
| A | Articular congruity must be restored |
| N | Non-anatomic reduction leads to arthritis |
| S | Single fragment dorsally Type 1 (coronal plane) | G | Greater displacement = higher type = worse prognosis | R | Restore medial column alignment | N | Non-anatomic reduction leads to arthritis |
| A | Angulation of forefoot (dorsomedial-plantarlateral) Type 2 | E | Each type increases AVN and nonunion risk | Z | Zone of comminution affects outcome | ||
| N | Numerous fragments (comminuted) Type 3 | O | ORIF indicated for all displaced body fractures | A | Articular congruity must be restored |
Hook:Types 1-2-3: Coronal-Oblique-Comminuted (increasing severity)
Mnemonic
STRESS
Navicular Stress Fracture Features
| S | Sagittal orientation vertical fracture line |
| T | Track and field athletes most at risk |
| R | Rest non-weight-bearing) for 6-8 weeks |
| E | Early CT/MRI as X-rays often negative |
| S | Surgery if displaced or failed conservative |
| S | Slow healing due to poor blood supply |
| S | Sagittal orientation vertical fracture line | R | Rest non-weight-bearing) for 6-8 weeks | S | Surgery if displaced or failed conservative |
| T | Track and field athletes most at risk | E | Early CT/MRI as X-rays often negative | S | Slow healing due to poor blood supply |
Hook:STRESS fractures need REST - 6-8 weeks non-weight-bearing
Overview
Tarsal Navicular Fractures
The tarsal navicular is a key bone of the midfoot, serving as the keystone of the medial longitudinal arch. Fractures range from minor avulsions to complex body fractures with significant displacement and associated injuries.
Clinical Significance
The navicular's tenuous blood supply makes it susceptible to avascular necrosis (AVN), similar to the scaphoid in the wrist. The central third is a watershed zone with limited vascularity, explaining the high nonunion rate in navicular stress fractures.
Classification by Location:
- Avulsion fractures - Most common (47%)
- Body fractures - Significant injuries, high complication rate
- Stress fractures - Important in athletes
- Tuberosity fractures - Posterior tibial tendon insertion
Epidemiology:
- Rare injuries - navicular fractures comprise 3-5% of all foot fractures
- Body fractures often associated with high-energy trauma
- Stress fractures common in athletes (track and field, basketball, football)
- Male predominance in body fractures
- Peak age: 20-40 years
Anatomy and Blood Supply
Navicular Anatomy - Know Cold for Viva
The navicular bone:
- Location: Keystone of medial longitudinal arch
- Articulations: Talus (proximally), three cuneiforms (distally), cuboid (laterally)
- Insertions: Posterior tibial tendon on tuberosity (major dynamic arch support)
- Shape: Boat-shaped (Latin: navicula = little boat)
Key relationships:
- Part of Chopart (transverse tarsal) joint with talus
- Forms talonavicular joint - critical for hindfoot motion
- Spring ligament supports plantar surface
Blood Supply - Critical Exam Topic
Watershed Zone
The navicular's blood supply is tenuous and similar to the scaphoid:
Arterial Supply:
- Dorsalis pedis artery - dorsal branches
- Medial plantar artery - plantar branches
- These vessels enter from the periphery (medial and lateral)
Watershed Zone:
- The central third of the navicular body is relatively avascular
- Blood supply enters peripherally and does not reach central zone reliably
- This explains high AVN rate in body fractures (25%) and stress fractures
Clinical Implication:
- Central stress fractures have high nonunion rate
- Displaced body fractures disrupt peripheral blood supply
- Open reduction should preserve soft tissue attachments
Functional Anatomy
Medial Column:
- Navicular is the "cornerstone" of the medial column
- Medial column: talus → navicular → medial cuneiform → first metatarsal
- Maintains longitudinal arch height
- Shortening leads to planovalgus deformity
Talonavicular Joint:
- Provides 80% of hindfoot inversion/eversion
- Essential for gait adaptation to uneven surfaces
- Loss of motion significantly affects function
Fracture Types by Location
| Fracture Type | Percentage | Mechanism | Key Features |
|---|---|---|---|
| Avulsion (dorsal lip) | 47% | Talonavicular capsule pull | Low energy, good prognosis |
| Tuberosity | 24% | PTT avulsion or direct trauma | May need fixation if large |
| Body | 26% | High-energy axial load | High complication rate |
| Stress | 3% | Repetitive loading | Athletes, central location |
Classification Systems
Sangeorzan Classification for Body Fractures
The Sangeorzan classification (1989) categorizes navicular body fractures based on fracture pattern and degree of displacement.
Type 1
Coronal plane fracture
- Transverse fracture line
- Dorsal fragment
- No forefoot angulation
- Talonavicular joint intact
- Treatment: ORIF if displaced
- Prognosis: Good if reduced
Type 2
Dorsomedial to plantar-lateral
- Main fracture oblique
- Forefoot displaced dorsally
- Medial column shortened
- Most common pattern
- Treatment: ORIF essential
- Prognosis: Moderate - AVN risk
Type 3
Comminuted
- Central/lateral comminution
- Severe articular damage
- Often high-energy
- Associated injuries common
- Treatment: ORIF + bone graft
- Prognosis: Poor - high AVN/arthritis
Clinical Application:
- Higher type = worse prognosis
- Type 2 most common in clinical practice
- All require CT for surgical planning
These fracture patterns guide treatment decisions and prognosis estimation.
Clinical Assessment
History
Body Fractures:
- High-energy mechanism (MVA, fall from height)
- Axial loading through foot
- Immediate inability to weight-bear
- Associated injuries common (25%)
Stress Fractures:
- Insidious onset of midfoot pain
- Worse with activity, improves with rest
- Often delay in presentation (weeks to months)
- Athletes: recent increase in training intensity
- May recall specific incident when "stress" became "complete"
Examination
Inspection:
- Swelling over dorsum of midfoot
- Ecchymosis (body fractures)
- May appear grossly normal (stress fractures)
- Assess overall foot alignment
Palpation:
- N spot - focal tenderness over navicular body (dorsal, medial, plantar)
- Tuberosity tenderness (posterior tibial tendon insertion)
- Assess adjacent joints (talonavicular, cuneonavicular)
Special Tests:
- Single-leg hop test (stress fractures) - reproduces pain
- Navicular compression test
- Assess posterior tibial tendon function
- Assess hindfoot alignment
The N Spot
Navicular Stress Fracture Sign: The "N spot" is focal tenderness over the proximal dorsal navicular at the junction of the proximal and middle thirds - this is the site of stress fractures in the watershed zone.
Sensitivity: 81% Specificity: 100%
If N spot tenderness present in an athlete with activity-related midfoot pain, pursue advanced imaging even with negative X-rays.
Differential Diagnosis
Differential Diagnosis of Activity-Related Dorsal Midfoot Pain
| Condition | Distinguishing Features | Key Investigation |
|---|---|---|
| Navicular stress fracture | N-spot tenderness, insidious onset, athlete with high running load | MRI (oedema) then CT (sagittal central line) |
| Navicular stress reaction | Pain without a fracture line; bone-marrow oedema only | MRI - oedema, no cortical break |
| Tibialis posterior tendinopathy | Pain/tenderness along tendon and tuberosity, weak inversion, planovalgus | Ultrasound or MRI of tendon |
| Accessory navicular / os tibiale externum syndrome | Medial bony prominence, tenderness at accessory ossicle, often bilateral | X-ray (oblique), MRI for synchondrosis oedema |
| Midtarsal (Chopart) sprain / Lisfranc injury | Plantar ecchymosis, pain on midfoot stress, weight-bearing films abnormal | Weight-bearing X-ray, CT |
| Talonavicular osteoarthritis | Older patient, chronic stiffness, dorsal osteophyte, reduced hindfoot motion | Weight-bearing X-ray |
| Kohler disease (paediatric) | Child 4-7y, sclerotic/fragmented navicular, self-limiting | X-ray; clinical age context |
| Extensor tendinopathy / dorsal ganglion | Superficial dorsal pain, no bony tenderness on N-spot | Ultrasound |
Associated Injuries
Body fractures often occur with:
- Cuboid fractures (nutcracker injury)
- Cuneiform fractures
- Lisfranc injuries
- Talus fractures
- Chopart joint injuries
Assessment:
- Examine entire foot systematically
- Compare to contralateral side
- Document neurovascular status
- Check for compartment syndrome (rare)
Investigations
Imaging Protocol
X-Rays (Standard Foot Series):
- AP, lateral, oblique views
- Body fractures usually visible
- Stress fractures often negative initially (up to 70%)
- Look for subtle cortical break or sclerosis
CT Scan:
- Essential for body fractures - surgical planning
- Assess articular displacement
- Identify comminution pattern
- Evaluate adjacent injuries
- Sangeorzan classification confirmed
MRI:
- Gold standard for stress fractures
- T2 bone marrow edema before cortical break
- 97% sensitivity for stress fractures
- Also evaluates soft tissue injury
Bone Scan:
- Alternative to MRI for stress fractures
- Highly sensitive (early uptake)
- Less specific than MRI
- "Hot" navicular in stress fracture/reaction
Imaging Findings
Body Fractures on CT:
- Fracture pattern (Sangeorzan type)
- Articular step-off measurement
- Comminution assessment
- Medial column length
Stress Fractures on MRI:
- T1: Low signal linear fracture line
- T2/STIR: High signal bone marrow edema
- Location: Central third, sagittal orientation
- Assess for complete vs partial fracture
CT vs MRI
Choose based on fracture type:
- Body fractures: CT for surgical planning
- Stress fractures: MRI for diagnosis and staging
- Both: May be needed for complete evaluation
CT shows bone detail; MRI shows stress reaction before cortical break.
Management Algorithm
Algorithm
Body Fracture Management
Non-Operative Treatment:
Indications:
- Non-displaced fractures (less than 1mm articular step-off)
- No medial column shortening
- Stable fracture pattern
- Patient able to comply with restrictions
Protocol:
- Short leg cast, non-weight-bearing for 6-8 weeks
- X-rays at 2, 4, 6 weeks to assess alignment
- CT at 6 weeks to confirm union
- Transition to weight-bearing boot at 8-10 weeks
- Progressive rehabilitation
Operative Treatment:
Surgical Indications
Absolute indications:
- Displacement greater than 1mm articular step-off
- Medial column shortening
- Unstable fracture pattern (Sangeorzan 2 and 3)
- Open fracture
Relative indications:
- Associated midfoot injuries requiring surgery
- High-demand patient
- Inability to comply with non-weight-bearing
Fixation Options:
- Screws: 3.5mm or 4.0mm cortical lag screws
- K-wires: Temporary or definitive for small fragments
- Mini-fragment plates: 2.0-2.4mm for comminuted fractures
- Bridge plating: Talonavicular to cuneiforms for severe comminution
- External fixation: Severely comminuted with soft tissue compromise
Choice depends on fracture pattern and comminution degree.
Mnemonic
FIXATION
Surgical Principles for Navicular Fractures
| F | Fix displaced fractures greater than 1mm step-off |
| I | Incision dorsomedial to preserve blood supply |
| X | X-rays intraoperatively to confirm reduction |
| A | Anatomic articular reduction essential |
| T | Temporary K-wires to hold reduction while screwing |
| I | Interfragmentary compression if pattern allows |
| O | ORIF with screws or mini-plates |
| N | Non-weight-bearing postoperatively 6-8 weeks |
| F | Fix displaced fractures greater than 1mm step-off | A | Anatomic articular reduction essential | O | ORIF with screws or mini-plates |
| I | Incision dorsomedial to preserve blood supply | T | Temporary K-wires to hold reduction while screwing | N | Non-weight-bearing postoperatively 6-8 weeks |
| X | X-rays intraoperatively to confirm reduction | I | Interfragmentary compression if pattern allows |
Hook:FIXATION principles guide surgical treatment of navicular body fractures
Surgical Technique
Preoperative Planning
Essential Steps:
- Review CT scan for fracture pattern and comminution
- Assess soft tissue envelope - may need staged surgery
- Plan approach based on fracture location
- Prepare for bone grafting if comminution present
Patient Positioning
- Supine with bump under ipsilateral hip
- Thigh tourniquet
- Image intensifier positioned for AP and lateral views
Thorough planning ensures optimal surgical execution.
Complications
Common Complications
Early Complications
- Wound dehiscence
- Infection
- Hardware prominence
- Neurovascular injury
- Compartment syndrome (rare)
Late Complications
- Avascular necrosis (25%)
- Nonunion (especially stress fractures)
- Malunion and planovalgus
- Post-traumatic arthritis
- Chronic pain
Avascular Necrosis
AVN - Major Complication
Risk Factors for AVN:
- Sangeorzan Type 2 and 3 fractures
- Delayed treatment
- Open reduction with extensive soft tissue stripping
- Associated injuries disrupting blood supply
Presentation:
- Persistent pain despite apparent healing
- Progressive collapse on imaging
- Sclerosis followed by fragmentation
Management:
- Early: Protected weight-bearing, may revascularize
- Established AVN with collapse:
- Bone grafting (vascularized or non-vascularized)
- Talonavicular fusion
- Triple arthrodesis (severe cases)
Nonunion
Risk Factors:
- Central stress fractures (watershed zone)
- Inadequate immobilization
- Smoking
- Delayed diagnosis
- Poor blood supply
Treatment:
- Bone stimulator (electrical/ultrasound)
- Surgical fixation with bone grafting
- Consider vascularized bone graft for resistant cases
Malunion
Consequences:
- Medial column shortening → planovalgus deformity
- Talonavicular arthritis
- Altered gait mechanics
- Chronic midfoot pain
Treatment:
- Osteotomy and bone grafting (rarely successful)
- Typically requires talonavicular fusion
- May need triple arthrodesis for severe deformity
Postoperative Care
Immediate Postoperative Period (0-2 weeks)
Hospital Care:
- Posterior splint, strict elevation above heart
- Non-weight-bearing with crutches
- Ice and analgesia
- Neurovascular checks
- DVT prophylaxis if high risk
Discharge Instructions:
- Maintain non-weight-bearing status
- Keep splint dry and clean
- Elevation as much as possible
- Watch for excessive pain, swelling, numbness
Early Phase (2-6 weeks)
Week 2:
- Wound check, suture removal
- Convert to short leg cast or CAM boot
- Continue strict non-weight-bearing
- Begin ankle pumps and toe exercises
Week 4:
- X-rays to assess alignment
- Continue non-weight-bearing
- If stable, may begin gentle ankle ROM in boot
Week 6:
- X-rays to assess early healing
- CT if healing questionable
- Continue non-weight-bearing until bridging callus seen
Mid Phase (6-12 weeks)
Week 8:
- If healing progressing, begin progressive weight-bearing
- Weight-bearing as tolerated in boot
- Physical therapy: ROM, proprioception
- Pool therapy if available
Week 10-12:
- Transition to supportive shoe
- Continue progressive weight-bearing
- Advance strengthening exercises
- Address gait abnormalities
Late Phase (3-6 months)
Months 3-4:
- Full weight-bearing in supportive footwear
- Sport-specific rehabilitation begins
- Impact activities avoided
Months 4-6:
- Gradual return to running (if athlete)
- Sport-specific drills
- Full return to sport if pain-free and full ROM
- Hardware removal if prominent (rarely needed)
Red Flags During Recovery
Concerning Signs
- Persistent pain despite adequate healing time - consider AVN
- Loss of reduction on serial X-rays - may need revision
- No progression of healing at 12 weeks - nonunion risk
- Wound complications - infection risk
- Progressive collapse on imaging - AVN developing
Return to Sport Criteria
Must achieve before clearance:
- Pain-free weight-bearing and walking
- Full or near-full ROM compared to contralateral
- Radiographic union (bridging callus on CT)
- Successful completion of sport-specific drills
- Single-leg hop test equal to contralateral
- Psychological readiness
Typical timeline:
- Office workers: 8-12 weeks
- Manual laborers: 12-16 weeks
- Athletes (non-impact): 4-6 months
- Athletes (impact/running): 6-9 months
Outcomes and Prognosis
Overall Outcomes by Fracture Type
Body Fractures - Operative
Good-Excellent Outcomes: 70-85%
- Type 1 (coronal): 85-90% good outcomes
- Type 2 (oblique): 70-80% good outcomes
- Type 3 (comminuted): 50-60% good outcomes
- AVN rate: 16-25%
- Arthritis rate: 20-30% at 5 years
Stress Fractures
Union Rate: 86-95% with early treatment
- Partial fractures: 95% union
- Complete non-displaced: 85-90% union
- Central location: Higher nonunion rate
- Return to sport: 80-90% of athletes
- Recurrence rate: 10-15%
Prognostic Factors
Good Prognosis Indicators:
- Early diagnosis and treatment (within 2 weeks)
- Anatomic reduction achieved
- Non-displaced or minimally displaced fractures
- Peripheral location (stress fractures)
- Younger age
- Non-smoker
- Good compliance with rehabilitation
Poor Prognosis Indicators:
- Delayed treatment (beyond 3 weeks)
- Sangeorzan Type 3 (comminuted)
- Severe articular damage
- Associated injuries (cuboid, cuneiforms)
- Central stress fracture location
- Smoking
- Poor soft tissue envelope
Functional Outcomes
Return to Work:
- Sedentary work: 8-12 weeks
- Light manual work: 12-16 weeks
- Heavy manual work: 16-24 weeks
Return to Sport:
- Low-impact activities: 3-4 months
- Running/jumping sports: 6-9 months
- Elite athletes: May require 9-12 months
- 10-20% of athletes unable to return to pre-injury level
Long-Term Complications
5-Year Follow-up Data:
- Post-traumatic arthritis: 20-40% (body fractures)
- Chronic pain: 15-25%
- Reduced activity level: 20-30%
- Need for fusion surgery: 5-10%
AVN Natural History:
- Develops within first 2 years post-injury
- May revascularize in 30% of cases
- Progressive collapse in 50-70% if severe
- Often requires salvage fusion procedures
Quality of Life
Patient Counseling
Key messages for patients:
-
Body fractures: "Most patients do well with surgery, but there is a 1 in 4 chance of blood supply problems (AVN) and a 1 in 5 chance of arthritis developing over time."
-
Stress fractures: "With strict rest for 6-8 weeks, 9 out of 10 athletes heal and return to sport. The bone heals slowly because of limited blood supply."
-
Time off sport: "Expect 6-9 months before full return to impact sports. Rushing increases risk of re-fracture or failure to heal."
Evidence Base
Sangeorzan Classification of Navicular Body Fractures (1989)
Sangeorzan BJ, Benirschke SK, Mosca V, Mayo KA, Hansen ST • J Bone Joint Surg Am (1989)
Key Findings:
- 21 displaced body fractures treated with ORIF over 1980-1987, classified into 3 types by fracture-line direction and forefoot displacement (Type 1 coronal, no forefoot angulation; Type 2 dorsal-lateral to plantar-medial with medial forefoot displacement; Type 3 sagittal comminution with lateral forefoot displacement). Satisfactory reduction achieved in 100% of Type 1, 67% of Type 2 and 50% of Type 3. Good result in 67%, fair in 19%, poor in 14%. Fracture type and accuracy of reduction both correlated directly with outcome.
Clinical Implication: Defining classification for navicular body fractures. Guides surgical planning and prognosis - higher type and imperfect reduction predict worse results.
Conservative vs Surgical Management of Navicular Stress Fractures (Khan, 1992)
Khan KM, Fuller PJ, Brukner PD, Kearney C, Burry HC • Am J Sports Med (1992)
Key Findings:
- 82 athletes with 86 CT-confirmed navicular stress fractures. 19 of 22 (86%) treated with at least 6 weeks of non-weight-bearing cast immobilisation returned to sport, versus only 9 of 34 (26%) who continued weight-bearing with activity restriction (p less than 0.001). CT appearance of healing did not reliably mirror clinical union.
Clinical Implication: Strict non-weight-bearing cast immobilisation is the treatment of choice; weight-bearing with activity restriction fails in most athletes. Healing should be judged clinically, not by CT alone.
NWB vs Surgery for Navicular Stress Fracture - Meta-analysis (Torg, 2010)
Torg JS, Moyer J, Gaughan JP, Boden BP • Am J Sports Med (2010)
Key Findings:
- Systematic review and mixed-model meta-analysis comparing three strategies. Non-weight-bearing conservative treatment gave 96% successful outcomes versus 82% for surgery, with no statistically significant difference (p=0.64) but a trend favouring NWB. Weight-bearing conservative treatment was significantly inferior to both NWB (p=0.0001) and surgery (p less than 0.0003).
Clinical Implication: Non-weight-bearing immobilisation is the standard of care for both partial and complete navicular stress fractures; surgery offers no proven advantage over NWB. Weight-bearing 'rest' is inadequate.
CT-Based Classification of Navicular Stress Fractures (Saxena, 2000)
Saxena A, Fullem B, Hannaford D • J Foot Ankle Surg (2000)
Key Findings:
- 22 navicular stress fractures with a proposed frontal-plane CT classification: Type I dorsal cortical break, Type II propagation into the body, Type III propagation through a second cortex. Type III took significantly longer to return to activity (mean 6.8 months) than Type I (3.0) or Type II (3.6). Operative cases returned faster than conservative (3.1 vs 4.3 months, p=0.02). Sclerotic margins were associated with persistent symptoms.
Clinical Implication: CT depth of the fracture (Saxena type) stratifies prognosis and informs the operative threshold; Type III and sclerotic-margin fractures heal slowly and may warrant surgery.
Prospective Study of Navicular Stress Fractures (Saxena, 2006)
Saxena A, Fullem B • Foot Ankle Int (2006)
Key Findings:
- Prospective series of 19 athletes (compared with 22 historical controls). Mean return to activity was 4.0 months across all CT types, with no major difference between Type I (3.8), Type II (3.7) and Type III (4.2) when treated per protocol (non-op for Type I, ORIF for Type II/III). 15 of 16 competitive athletes returned to full competition, including all who had ORIF.
Clinical Implication: Both operative and well-managed non-operative pathways achieve approximately 4-month return to activity; CT type should guide the choice, with surgery reserved for deeper (Type II/III) injuries.
Bridge Plating of the Medial Column in Midfoot Injuries (Schildhauer, 2003)
Schildhauer TA, Nork SE, Sangeorzan BJ • J Orthop Trauma (2003)
Key Findings:
- Describes temporary internal bridge plating of the medial column with an 8-10 hole 2.7mm reconstruction plate spanning the talar neck to the first metatarsal for severe comminuted midfoot (cuneiform/navicular) crush injuries, maintaining medial column length and alignment until union, as an alternative to spanning external fixation.
Clinical Implication: For comminuted navicular body fractures too fragmented for lag-screw fixation, span the medial column to preserve length and arch; outcomes after midfoot injury correlate with restoring the medial longitudinal arch.
Minifragment Plate Fixation of High-Energy Navicular Body Fractures (Evans, 2011)
Evans J, Beingessner DM, Agel J, Benirschke SK • Foot Ankle Int (2011)
Key Findings:
- 24 navicular body fractures treated with minifragment plate ORIF at a Level I trauma centre. All fractures united with no loss of reduction and no deep infection. Only 1 patient (4%) developed radiographic avascular collapse; 4 (17%) developed talonavicular arthrosis and 4 (17%) required removal of prominent hardware.
Clinical Implication: Minifragment plating is a reliable alternative to independent lag screws for comminuted body fractures, achieving union with a low rate of avascular collapse when soft-tissue handling is careful.
Tarsal Navicular Stress Fractures - Original Series (Torg, 1982)
Torg JS, Pavlov H, Cooley LH, Bryant MH, Arnoczky SP, Bergfeld J, Hunter LY • J Bone Joint Surg Am (1982)
Key Findings:
- Foundational retrospective review of 21 tarsal navicular stress fractures in athletes. Established that the diagnosis is frequently delayed because routine radiographs are often normal, that the fracture characteristically lies in the central third in a sagittal plane, and that immobilisation with non-weight-bearing was more reliable than continued activity.
Clinical Implication: The original description of navicular stress fracture - central sagittal location, radiographically occult, and dependent on rest/immobilisation for healing. A high index of suspicion in athletes remains essential.
Viva Scenarios
Clinical Decision Scenarios
Use these scenarios to practise clinical reasoning and management decisions
CLINICAL SCENARIOStandard
CLINICAL PROMPT
"A 25-year-old track athlete presents with 6 weeks of worsening midfoot pain during running. The pain localizes to the dorsum of the foot over the navicular. X-rays appear normal."
PRACTICAL APPROACH
Differential Diagnosis:
- Navicular stress fracture - most likely given history and location
- Midfoot sprain/ligament injury
- Posterior tibial tendinopathy
- Stress reaction (pre-fracture)
- Extensor tendinopathy
Clinical Assessment:
- Test for N spot tenderness - dorsal navicular at proximal-middle third junction
- Single-leg hop test - positive if reproduces pain
- Assess posterior tibial tendon function
- Examine entire midfoot
Imaging:
- X-rays often negative in early stress fractures (up to 70%)
- MRI is investigation of choice - shows bone marrow edema before cortical break
- CT if MRI confirms fracture - assess displacement
Management if Stress Fracture Confirmed:
- Strict non-weight-bearing for 6-8 weeks - critical for healing
- Short leg cast or CAM boot
- Repeat imaging at 6 weeks to confirm healing
- Gradual return to activity over 4-6 weeks
- Address training errors and biomechanics
KEY CLINICAL POINTS
Navicular stress fracture - high index of suspicion
N-spot tenderness is specific sign
MRI is gold standard (X-rays often negative)
Strict Non-Weight Bearing (6-8 wks)
COMMON PITFALLS
Diagnosing 'midfoot sprain' without imaging
Allowing weight-bearing in a boot (high nonunion risk)
Missing the central location (watershed zone)
FURTHER QUESTIONS
"Why is the central third prone to nonunion?"
"When is surgery indicated for stress fractures?"
"What is the N-spot?"
CLINICAL SCENARIOChallenging
CLINICAL PROMPT
"A 35-year-old man is brought to ED after a motorcycle accident. He has a swollen, deformed midfoot. X-rays show a displaced navicular body fracture with associated cuboid fracture. CT shows a Sangeorzan Type 2 pattern with 5mm of medial column shortening."
PRACTICAL APPROACH
Preoperative Assessment:
- ATLS assessment - exclude other injuries
- Neurovascular exam of foot
- Assess soft tissue envelope - may need staged surgery
- CT review: Sangeorzan Type 2, medial column shortening, cuboid involvement
Surgical Planning:
- Timing: Ideally within 2 weeks if soft tissues allow
- Approach: Dorsomedial for navicular, separate lateral approach for cuboid
- Goals: Restore medial column length, anatomic articular reduction
Surgical Technique:
- Dorsomedial incision between tibialis anterior and EHL
- Protect dorsalis pedis artery and deep peroneal nerve
- Identify and expose fracture fragments
- Reduce medial column length with distraction
- Temporary K-wire fixation
- Definitive fixation: 3.5mm lag screws or mini-fragment plate
- Address cuboid through lateral approach
- Intraoperative fluoroscopy to confirm reduction
Postoperative:
- Posterior splint, strict non-weight-bearing
- 6-8 weeks NWB, then progressive weight-bearing
- Monitor for AVN - common in Type 2 fractures
KEY CLINICAL POINTS
High energy injury - check Compartment Syndrome
Medial Column Shortening leads to Planovalgus deformity
Sangeorzan Type 2 (Dorsomedial to Plantar-lateral)
ORIF required: Restore length and articular surface
COMMON PITFALLS
Fixing navicular but leaving medial column short
Missing the associated Nutcracker cuboid fracture
Damaging dorsalis pedis during approach
FURTHER QUESTIONS
"What is the Sangeorzan classification?"
"How does malunion affect foot biomechanics?"
"What approach would you use?"
CLINICAL SCENARIOAdvanced
CLINICAL PROMPT
"A 30-year-old athlete is 4 months post-operatively from navicular body fracture ORIF. She has persistent midfoot pain. X-rays show sclerosis and partial collapse of the navicular. What is your diagnosis and management?"
PRACTICAL APPROACH
Diagnosis:
- Avascular necrosis (AVN) of the navicular
- Incidence: 25% in body fractures, higher in Type 2/3
- Confirm with MRI: T1 hypointensity, lack of enhancement
Classification and Staging:
- Stage 1: Normal X-rays, MRI changes only
- Stage 2: Sclerosis without collapse
- Stage 3: Partial collapse, subchondral fracture
- Stage 4: Complete collapse, secondary arthritis
Management Options:
Early AVN (Stage 1-2):
- Protected weight-bearing - may allow revascularization
- Core decompression (limited evidence)
- Observation with serial imaging
Established AVN with Collapse (Stage 3-4):
- Bone grafting: Non-vascularized or vascularized (medial femoral condyle)
- Talonavicular fusion: If articular destruction, provides pain relief
- Triple arthrodesis: Severe deformity, pantalar involvement
Counseling:
- Prognosis guarded for return to high-level sport
- May require activity modification long-term
- Fusion procedures eliminate talonavicular motion
KEY CLINICAL POINTS
AVN is common (25%) due to watershed supply
Diagnosis: MRI confirms early, CT shows collapse
Early: NWB and observation
Late (collapse): Fusion (Talonavicular or Triple)
COMMON PITFALLS
Confusing AVN with infection
Promising full return to elite sport after fusion
Ignoring adjacent joint arthritis
FURTHER QUESTIONS
"What are the stages of AVN?"
"What is the blood supply of the navicular?"
"Why is the central third vulnerable?"
MCQ Practice Points
High-Yield Facts for MCQs
Stress Fracture Diagnosis
Q: A young athlete has vague midfoot pain but normal X-rays. What is the next step? A: MRI - X-rays are negative in 70% of early stress fractures. MRI is the gold standard (97% sensitive) showing bone marrow edema before a cortical break appears.
N-Spot Tenderness
Q: What is the 'N-Spot' and what does it signify? A: Dorsal Navicular Tenderness - Located at the junction of the proximal and middle thirds. It is 81% sensitive and 100% specific for navicular stress fractures.
Watershed Zone
Q: Why do central navicular fractures have a high nonunion rate? A: Poor Vascularity - The central third is a watershed zone between the dorsalis pedis and medial plantar arterial supplies. This tenuous blood supply impairs healing.
Sangeorzan Classification
Q: Which Sangeorzan type is the most common? A: Type 2 - The fracture line runs from dorsomedial to plantar-lateral. It results in forefoot medialization and dorsal displacement, requiring ORIF to restore length.
Treatment of Stress Fractures
Q: What is the critical management principle for navicular stress fractures? A: Variables: Strict NWB vs Surgery - Conservative management requires 6-8 weeks of strict non-weight-bearing in a cast. Weight-bearing leads to nonunion or recurrence.
Surgical Threshold
Q: When is surgery indicated for a navicular body fracture? A: Greater than 1mm Displacement - Any articular step-off greater than 1mm or loss of medial column length warrants ORIF to prevent post-traumatic arthritis and deformity.
Guidelines, Registries & Global Practice
Global Epidemiology
Navicular fractures are uncommon. Across published series the navicular accounts for only a small fraction of foot fractures, with body fractures usually following high-energy axial loading and stress fractures clustering in running and jumping athletes. There is no dedicated international registry for navicular fractures (unlike arthroplasty), so the evidence base is built from case series and a single meta-analysis rather than registry data.
Defining Evidence and Diagnostic Benchmarks
| Parameter | Figure | Source (PubMed) |
|---|---|---|
| NWB cast return-to-sport (stress #) | 86% vs 26% for weight-bearing | Khan 1992 (PMID 1456359) |
| NWB vs surgery success (meta-analysis) | 96% vs 82% (NS; WB inferior) | Torg 2010 (PMID 20197494) |
| Good/fair/poor after body-# ORIF | 67% / 19% / 14% | Sangeorzan 1989 (PMID 2592390) |
| Union after minifragment plating | 100% union, 4% avascular collapse | Evans 2011 (PMID 21733456) |
| Return to activity by CT type | Type I/II ~3.7 mo, Type III ~6.8 mo | Saxena 2000/2006 (PMID 10789100, 17144953) |
Guideline & Society Positions
No single national body publishes a stand-alone navicular-fracture guideline; recommendations are drawn from foot-and-ankle society consensus, AO principles and the sports-medicine literature. The table below summarises the practical position of the major bodies.
Society / System Guidance Compared
| Body / System | Position | Evidence level |
|---|---|---|
| AO Foundation | Restore medial column length and articular congruity; lag screws for simple patterns, bridge/minifragment plating for comminution | Expert consensus / Level IV-V |
| AAOS (USA) | CT for surgical planning of body fractures; ORIF for displacement greater than 1-2mm or medial column shortening | Expert opinion |
| BOA / BOAST (UK) | Open midfoot injuries follow BOAST open-fracture and dislocated/deformed-limb standards (early reduction, prompt senior review) | Standard of care |
| EFORT / European F&A | CT mandatory for body fractures; medial-column preservation is the key prognostic target | Expert consensus |
| Sports-medicine consensus | Non-weight-bearing immobilisation is standard of care for stress fractures; surgery for Type III / failed conservative | Level III meta-analysis (Torg 2010) |
Registry & Practice Variation
- No arthroplasty-style registry captures navicular fractures, so practice variation is large and outcome data come from single-centre series.
- Stress-fracture management has converged internationally on strict non-weight-bearing immobilisation following Khan 1992 and the Torg 2010 meta-analysis; however, real-world audits (e.g. Burne 2005, PMID 16157855) show many patients still do not receive guideline non-weight-bearing treatment, and only about half of those return to their previous sporting level.
- Body-fracture fixation varies between independent lag screws and minifragment/bridge plating depending on comminution and surgeon preference; both achieve high union when medial column length is restored.
Australian Context
Within Australia, high running-load football codes (AFL, rugby league/union) and track and field generate most stress fractures, while construction and mining account for high-energy body fractures. MRI and CT are available through both public and private systems, and operative care for displaced fractures is provided at major trauma centres with foot-and-ankle subspecialists, with regional and remote patients often transferred or followed up via telehealth. Australian Institute of Sport return-to-running protocols and bone-health screening for recurrent stress fractures are widely applied. Reimbursement schedule codes are deliberately omitted as they are not clinically relevant to exam practice.