Skip to main content
Symptom
dx.
Menu
Clinical Reference
Approaches
I have a symptom
Management
I know the diagnosis
Orthopedic Injuries
Fractures & dislocations
Medications
Drug reference
Calculators
Clinical calculators
OHIP Billing
Billing code lookup
Practical Skills
ECG
Interpretation guide
POCUS
Bedside ultrasound
Procedures
Step-by-step guides
Resuscitation
ACLS / PALS / NRP
Learn
Blog
Articles & updates
Deep Dive
In-depth clinical reviews
About
Our mission
Symptom
dx.
Clinical Reference
Approaches
I have a symptom
Management
I know the diagnosis
Orthopedic Injuries
Fractures & dislocations
Medications
Drug reference
Calculators
Clinical calculators
OHIP Billing
Billing code lookup
Practical Skills
ECG
Interpretation guide
POCUS
Bedside ultrasound
Procedures
Step-by-step guides
Resuscitation
ACLS / PALS / NRP
Learn
Blog
Articles & updates
Deep Dive
In-depth clinical reviews
About
Our mission
Get Started
Menu
Clinical Reference
Approaches
I have a symptom
Management
I know the diagnosis
Orthopedic Injuries
Fractures & dislocations
Medications
Drug reference
Calculators
Clinical calculators
OHIP Billing
Billing code lookup
Practical Skills
ECG
Interpretation guide
POCUS
Bedside ultrasound
Procedures
Step-by-step guides
Resuscitation
ACLS / PALS / NRP
Learn
Blog
Articles & updates
Deep Dive
In-depth clinical reviews
About
Our mission
Loading...
Syndesmotic injury (high ankle sprain)
Shoulder & Clavicle
AC separation
Biceps tendon rupture
Clavicle fracture
Humerus proximal fracture
Rotator cuff tear
Scapular fractures
Shoulder dislocations
SLAP tear
Sternoclavicular dislocation
Arm & Elbow
Compartment syndrome (anterior, lateral, deep - superficial posterior)
Coronoid process fracture
Elbow dislocations
Epicondylar fracture
Humeral shaft fracture
Intercondylar and condylar region fracture
Olecranon fracture
Radial head fracture (Mason I-IV)
Supracondylar fracture (pediatric and adult)
Triceps tendon rupture
Forearm, Wrist & Hand
Carpal bones fractures
Carpal dislocations and ligament injuries
Distal radius and ulna fracture
Fight bite (human bite over MCP)
Finger dislocations by joint
Finger open fractures - amputations
Forearm fractures
Hand and finger tendon and ligament injuries
Hand tendon injuries
Metacarpal fractures
Nail bed injuries
Phalangeal fractures
Tuft fracture
Spine
Cervical spine fracture (C1-C7)
Cord syndromes
Sacrum and coccyx fracture
Thoracic and lumbar spine fracture
Pelvis & Hip
Acetabular fractures
Hip dislocations
Pelvis fractures
Proximal femur fractures
Thigh & Knee
Distal femur fractures
Femoral shaft fractures
Knee dislocation
Knee ligament injuries
Patellar dislocation
Patellar fracture
Patellar tendon rupture
Pes anserine bursitis
Prepatellar bursitis
Quadriceps tendon rupture
Tibial plateau fracture
Tibial spine fracture
Tibial tubercle fracture
Leg & Shin
Achilles tendon rupture
Fibular shaft fracture
Proximal fibula fracture
Stress fracture (tibia-fibula)
Tibial and Fibular shaft fracture
Tibial shaft fracture
Toddler's fracture
Ankle
Ankle dislocation
Ankle fractures
Ankle sprain
Maisonneuve fracture (proximal fibula and syndesmosis)
Peroneal tendon dislocation or tear
Peroneal tendon tear or dislocation
Subtalar dislocation
Syndesmotic injury (high ankle sprain)
Foot
Calcaneus fracture
Cuboid fracture
Cuneiform fractures
Dancer's fracture (5th MT spiral shaft)
Jones fracture (5th MT base - metadiaphyseal junction)
Lisfranc injury (tarsometatarsal dislocation)
March fracture (metatarsal stress fracture)
Metatarsal fractures (1st-5th)
Navicular fracture
Plantar fascia rupture
Talus fracture
Tibialis posterior tendon dysfunction
Toe dislocations
Syndesmotic injury (high ankle sprain)
POCUS
Procedures
Medications
Calculators
Resuscitation
ECG Guide
Back
Clinical Assessment Checklist
Browse categories and answer follow-up questions to refine your symptom profile.
Approach to the Critical Patient
Triage and limb threat
Initial priorities
▶
Open injury
▶
Gross contamination
Bone or tendon visible
Neurovascular compromise
▶
Dorsalis pedis pulse
Posterior tibial pulse
Compartment syndrome risk
▶
Pain out of proportion
Pain with passive toe motion
Unstable ankle mortise concern
▶
Inability to bear weight
Gross deformity
Immediate escalation triggers
▶
If pulseless or cool foot, immediate reduction if deformity and urgent vascular and orthopedics
▶
Bedside Doppler if pulses not palpable
If persistent deficit after reduction, urgent CT angiography lower extremity
If open injury, antibiotics and tetanus pathway before definitive splinting when feasible
▶
Sterile saline dressing
Avoid probing the wound
If fracture-dislocation, urgent reduction and post-reduction films
▶
Sedation readiness
Post-reduction neurovascular documentation
Key concepts
Syndesmotic injury framework
▶
Distal tibiofibular syndesmosis injury
▶
Anterior inferior tibiofibular ligament
Posterior inferior tibiofibular ligament
High ankle sprain terminology
▶
External rotation mechanism common
Deltoid injury increases instability risk
Stability decision point
▶
Stable syndesmosis
Unstable syndesmosis requiring operative stabilization
History
Mechanism and risk mapping
Injury context
▶
Mechanism
▶
External rotation on planted foot
Dorsiflexion with rotation
Energy
▶
Sports contact
High-energy twist with fall
Timing
▶
Time since injury
Prior reduction attempt
Function
▶
Ability to bear weight
Ability to push off or pivot
Associated injury clues
▶
Medial ankle pain
▶
Deltoid ligament injury concern
Occult medial malleolus injury concern
Proximal fibula pain
▶
Maisonneuve injury concern
Knee pain or instability symptoms
Persistent deep ankle pain
▶
Osteochondral talar lesion concern
Occult fracture concern
Patient factors
▶
Prior ankle sprains or instability
▶
Chronic syndesmotic insufficiency concern
Prior surgery or hardware
Bone health risk
▶
Osteoporosis risk factors
Chronic steroid use
Anticoagulation
▶
Bleeding risk
Hemarthrosis concern
Physical Exam
Inspection and palpation
Soft tissue and deformity
▶
Swelling distribution
▶
Anterolateral distal tibiofibular swelling
Medial swelling suggesting deltoid injury
Skin integrity
▶
Abrasions
Fracture blisters
Ecchymosis pattern
▶
Medial ecchymosis
Proximal fibula ecchymosis
Point tenderness mapping
▶
Syndesmotic region
▶
Anterior distal tibiofibular tenderness
Posterior distal tibiofibular tenderness
Medial structures
▶
Deltoid tenderness
Medial malleolus tenderness
Lateral structures
▶
Lateral malleolus tenderness
Peroneal tendon tenderness
Proximal fibula
▶
Fibular head tenderness
Proximal fibular shaft tenderness
Stability tests and neurovascular
Provocative maneuvers
▶
External rotation stress test
▶
Pain at syndesmosis
Medial clear space symptom reproduction
Squeeze test
▶
Mid-calf squeeze reproducing distal syndesmosis pain
Limited utility in acute swelling
Crossed-leg test
▶
Pain at syndesmosis with leg crossed and pressure on knee
Reproduction of deep ankle pain
Single-leg hop
▶
Avoid if suspected fracture or gross instability
Functional pain reproduction if safe
Neurovascular exam
▶
Pulses and perfusion
▶
Capillary refill
Skin temperature
Sensation
▶
Superficial peroneal nerve distribution
Deep peroneal nerve first web space
Motor
▶
Ankle dorsiflexion
Great toe extension
PITFALLS
▶
Normal pulses do not exclude evolving compartment syndrome
Isolated syndesmotic tenderness can coexist with occult fibular fracture
Failure to examine proximal fibula risks missing Maisonneuve injury
Differential Diagnosis
Acute ankle pain after twist
Primary consideration
▶
Syndesmotic sprain
▶
ICD-10 S93.43
SNOMED CT concept for distal tibiofibular ligament sprain
Unstable syndesmosis with mortise widening
▶
Deltoid injury association
Operative stabilization consideration
Fracture patterns
▶
Lateral malleolus fracture
▶
Weber B
Weber C with syndesmotic disruption risk
Posterior malleolus fracture
▶
PITFL avulsion association
CT for fragment size and incisura involvement
Medial malleolus fracture
▶
Mortise instability association
Deltoid equivalent pattern
Maisonneuve fracture
▶
Proximal fibula fracture with syndesmosis injury
Medial ankle injury common
Soft tissue mimics
▶
Lateral ankle sprain
▶
ATFL and CFL injury
Faster recovery typical than syndesmotic injury
Peroneal tendon injury
▶
Subluxation symptoms
Pain posterior to lateral malleolus
Osteochondral lesion of talus
▶
Persistent deep ankle pain
Locking or catching symptoms
Achilles injury
▶
Posterior ankle pain
Weak plantarflexion
Laboratory Tests
Routine labs and special scenarios
Labs generally not required
▶
Isolated closed stable sprain
▶
No routine CBC or chemistry
No routine inflammatory markers
Imaging-driven diagnosis
▶
Radiographs determine fracture pathway
MRI driven by clinical course and specialist plan
Trauma or operative pathway labs
▶
Procedural sedation consideration
▶
Point-of-care glucose if altered mental status
Pregnancy test if applicable
Open injury or polytrauma
▶
CBC for bleeding concern
Electrolytes and creatinine for contrast planning
Anticoagulation or significant bleeding concern
▶
INR if warfarin use
Platelets if thrombocytopenia concern
Diagnostic Tests
Scoring Systems
Classification and implications
▶
Weber ankle fracture classification
▶
Type A below syndesmosis
Type B at syndesmosis
Type C above syndesmosis
Implications for syndesmotic injury
▶
Weber C increased syndesmotic disruption risk
Weber B can have syndesmotic injury with instability
Ottawa Ankle Rules for radiographs
▶
Malleolar zone pain
Bone tenderness posterior edge or tip of malleolus
Inability to bear weight immediately and in ED
Radiographs
Initial imaging set
▶
Ankle series
▶
AP view
Mortise view
Lateral view
Tibia-fibula series when indicated
▶
Proximal fibula pain or tenderness
Weber C pattern or medial clear space widening
Mortise alignment metrics
▶
Tibiofibular clear space
▶
Increased clear space suggests syndesmotic disruption
Compare to contralateral if uncertain
Tibiofibular overlap
▶
Decreased overlap suggests syndesmotic disruption
Technique dependent and position sensitive
Medial clear space
▶
Increased space suggests deltoid disruption or talar shift
Mortise view required for interpretation
Stress and weight-bearing views
▶
External rotation stress radiographs
▶
Widening of medial clear space
Increased tibiofibular clear space
Gravity stress view
▶
Alternative to manual stress
Deltoid equivalent assessment
Weight-bearing mortise view
▶
Functional instability detection
Specialist-directed timing based on pain and safety
PITFALLS
▶
Normal non-stress films do not exclude unstable syndesmotic injury
Malrotation during X-ray can mimic syndesmotic widening
Proximal fibula imaging omission can miss Maisonneuve injury
MRI
Indications and yield
▶
Persistent symptoms with normal or equivocal radiographs
▶
Syndesmotic ligament grading
Deltoid ligament assessment
Return-to-sport planning and chronic pain
▶
Osteochondral talar lesion detection
Tendon injury detection
Surgical planning adjunct
▶
Extent of syndesmotic disruption
PITFL and interosseous ligament injury mapping
Interpretation pearls
▶
AITFL disruption common in syndesmotic sprain
▶
Edema pattern supports acute injury
Chronic scarring supports chronic instability
Deltoid injury increases instability risk
▶
Medial clear space correlation
Operative referral threshold lower
CT
Indications
▶
Suspected posterior malleolus fracture
▶
Fragment size estimation
Incisura involvement
Complex ankle fracture patterns
▶
Surgical planning
Occult fractures not seen on radiographs
Syndesmotic reduction assessment post-fixation
▶
Tibiofibular alignment comparison
Malreduction detection
Limitations and pearls
▶
Ligament injury not directly visualized as well as MRI
▶
Bony avulsions better detected than soft tissue
Use with clinical and radiographic correlation
Disposition
Stability-based pathways
ED discharge criteria
▶
Stable mortise on imaging
▶
No medial clear space widening on appropriate view
No concerning tibiofibular widening pattern
Neurovascularly intact
▶
Normal pulses
Normal motor and sensation
Pain controlled with oral regimen
▶
Safe mobilization with crutches or boot
Safe home supports
Urgent orthopedics criteria
▶
Mortise instability on stress or weight-bearing views
▶
Talar shift concern
Deltoid equivalent concern
Associated fracture
▶
Weber C pattern
Posterior malleolus fracture
Maisonneuve concern
▶
Proximal fibula fracture
Medial injury with distal syndesmosis tenderness
Admission or transfer criteria
▶
Open injury
▶
IV antibiotics required
Operative debridement pathway
Neurovascular compromise
▶
Persistent deficit after reduction
Vascular imaging and specialist involvement
Compartment syndrome concern
▶
Escalation for pressure measurement or surgical evaluation
Serial exams and monitoring
Follow-up timing
▶
Stable injury
▶
Sports medicine or orthopedics within 7 to 10 days
Repeat assessment for instability if swelling limited exam
Suspected unstable injury without definitive stress imaging
▶
Orthopedics within 3 to 5 days
Consider delayed stress or weight-bearing imaging per specialist
Treatment
Immediate life-saving interventions
Time-critical actions
▶
If open injury, initiate open fracture pathway
▶
Cefazolin IV 2 g
▶
Repeat every 8 hours
If weight 120 kg or higher, 3 g dosing per local protocol
If gross contamination or farm injury, add gentamicin IV 5 mg/kg
▶
Single daily dosing strategy
Renal dosing adjustment if impaired kidney function
Tetanus prophylaxis based on immunization status
▶
Tdap if not up to date
Tetanus immune globulin for unknown or incomplete series with dirty wound
If fracture-dislocation with threatened skin, reduction and splint
▶
Procedural sedation pathway if needed
Post-reduction neurovascular and imaging
If vascular compromise, immediate reduction if deformity and urgent vascular and orthopedics
▶
CT angiography if persistent deficit
Heparinization decision by vascular surgery
Immobilization and Splinting
Immobilization choice
▶
Posterior short leg plus stirrup
▶
Neutral dorsiflexion positioning
Swelling-phase non-circumferential construct
CAM boot for stable injuries
▶
Early protected motion protocol when appropriate
Remove for hygiene if safe and instructed
Immobilization principles
▶
Swelling accommodation
▶
Avoid circumferential cast in first 5 to 7 days if swelling expected
Two-finger tightness check
Post-application checks
▶
Pain trend after splinting
Distal perfusion and sensation reassessment
Weight-bearing status
▶
Suspected syndesmotic injury
▶
Non-weight-bearing initially if moderate to severe pain
Crutches instruction and safety
Confirmed stable low-grade injury
▶
Protected weight-bearing in boot as tolerated
Avoid pivot and external rotation
Reduction
Reduction scenarios
▶
Fracture-dislocation reduction pathway
▶
Traction and countertraction
▶
Recreate deformity to disengage if needed
Gentle sustained traction
Analgesia and sedation options
▶
Acetaminophen PO 1000 mg
▶
Maximum daily dose per patient factors
Lower maximum in liver disease
Ibuprofen PO 400 to 600 mg
▶
Every 6 to 8 hours as needed
Avoid in significant renal disease or GI bleed risk
Fentanyl IV 0.5 to 1 microgram/kg
▶
Repeat every 5 minutes to effect
Respiratory monitoring and readiness
Procedural sedation when required
▶
Ketamine IV 1 to 2 mg/kg
▶
Additional 0.5 mg/kg every 5 to 10 minutes as needed
Airway equipment at bedside
Propofol IV 0.5 to 1 mg/kg
▶
Additional 0.25 to 0.5 mg/kg every 2 to 3 minutes as needed
Continuous capnography
Post-reduction requirements
▶
Immediate neurovascular reassessment
Post-reduction ankle radiographs
Syndesmotic sprain without dislocation
▶
No reduction typically required
Avoid forceful manipulation
Open fracture medications and timing
Antibiotic timing targets
▶
As early as possible after identification
▶
First dose ideally within 60 minutes of presentation
Do not delay for imaging if clinically obvious
Contamination-based adjustments
▶
Freshwater exposure, add gram-negative coverage per local protocol
Soil contamination, broaden anaerobic coverage per local protocol
Tetanus prophylaxis logic
▶
Clean minor wound
▶
Booster if more than 10 years since last dose
No immune globulin if completed series
Dirty or major wound
▶
Booster if more than 5 years since last dose
Immune globulin if unknown or incomplete series
DVT prophylaxis when relevant
Risk assessment for lower limb immobilization
▶
High-risk features
▶
Prior venous thromboembolism
Active cancer
Major trauma or surgery planned
Contraindications
▶
Active bleeding
High bleeding risk
Prophylaxis options per local protocol
▶
Low molecular weight heparin example
▶
Enoxaparin 40 mg subcut daily
Renal dosing adjustment if eGFR low
Documentation of decision and rationale
▶
Risk tier
Planned duration linked to immobilization
Special Populations
Pregnancy
Maternal and fetal considerations
▶
Imaging approach
▶
Radiographs acceptable with shielding when indicated
MRI preferred for ligament assessment when needed and feasible
Analgesia selection
▶
Acetaminophen preferred
NSAID avoidance in later pregnancy per obstetric guidance
VTE risk
▶
Pregnancy increased baseline thrombosis risk
Immobilization increases thrombosis risk further
Geriatric
Age-related considerations
▶
Occult fracture risk
▶
Lower threshold for advanced imaging if persistent pain
Osteoporosis and fragility fracture context
Mobility and fall risk
▶
Early physiotherapy referral when appropriate
Home safety planning
Medication safety
▶
NSAID renal and GI risk higher
Opioid delirium risk higher
Pediatrics
Pediatric-specific issues
▶
Physeal injury mimic
▶
Salter-Harris consideration with normal radiographs
Immobilize and re-evaluate if high suspicion
Exam limitations
▶
Pain-limited stress testing avoidance
Parent-assisted observation of gait when safe
Follow-up needs
▶
Early reassessment if persistent pain
Sports clearance individualized
Background
Epidemiology
Frequency and contexts
▶
Proportion of ankle sprains
▶
Reported range 1% to 11% of ankle sprains
Higher proportions reported in collision and cutting sports
Athletic populations
▶
Reported rates up to 25% in some sport cohorts
Under-recognition common with normal radiographs
Pathophysiology
Mechanism to injury mapping
▶
External rotation force
▶
AITFL injury common earliest component
Interosseous membrane extension with higher energy
Dorsiflexion component
▶
Wider anterior talar dome increases syndesmosis stress
Talar external rotation drives tibiofibular separation
Instability determinants
▶
Deltoid ligament disruption increases talar shift risk
Posterior malleolus and PITFL involvement affects stability
Therapeutic Considerations
Recovery and prognosis
▶
Longer recovery than lateral ankle sprain
▶
Return to sport often 6 to 8 weeks or longer in moderate to severe injury
Persistent pain common if instability missed
Stable versus unstable treatment divergence
▶
Stable injuries respond to immobilization and rehab
Unstable injuries often require syndesmotic fixation
Guideline alignment and evidence levels
▶
Imaging for instability guided by orthopedic consensus
▶
Stress or weight-bearing radiographs for suspected instability
MRI for persistent symptoms with equivocal films
Operative stabilization indications based on expert consensus
▶
Mortise widening
Talar shift
Patient Discharge Instructions
copy discharge instructions
Copy
Discharge instructions
▶
Weight-bearing restriction
▶
Non-weight-bearing unless explicitly cleared
Crutches or walker use
Immobilization care
▶
Keep splint dry
Do not insert objects into splint
Swelling control
▶
Elevation above heart level
Ice over splint as tolerated
Pain control plan
▶
Acetaminophen as directed
NSAID only if safe for kidneys and stomach
Return immediately for
▶
Increasing pain not controlled
New numbness or weakness
Toes cold, pale, or blue
Splint too tight or worsening swelling
Fever or drainage if wound present
Follow-up
▶
Orthopedics or sports medicine within 7 to 10 days
Earlier follow-up in 3 to 5 days if instability suspected or severe pain
References
Guidelines and key sources
Source set
▶
Orthopedic and sports medicine consensus statements on syndesmotic injury evaluation and stability
▶
Stress radiographs for instability assessment
Operative fixation for mortise widening or talar shift
Ottawa Ankle Rules validation literature
▶
Radiograph decision support for ankle injuries
High sensitivity for clinically significant fractures
Imaging references for syndesmotic injury
▶
MRI for ligament injury characterization
CT for posterior malleolus and reduction assessment
Project instruction source :contentReference[oaicite:0]{index=0}
▶
Formatting and nesting rules followed
Checkbox-only database-optimized structure
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.
← Orthopedic Injuries
Home
Orthopedic Injuries
Syndesmotic injury (high ankle sprain)