›Immediate triage to monitored bed if severe pain with deformity
›Immediate triage to monitored bed if neurovascular concern
›Continuous pulse oximetry if respiratory distress or sedation planned
›Cardiac monitor if syncope or hemodynamic instability
›Two large bore IV if shock concern or major trauma
›Immediate analgesia within 15 minutes if severe pain
Vital sign danger thresholds
›Danger thresholds
›Systolic blood pressure less than 90 mmHg
›Heart rate greater than 120 per minute
›Respiratory rate greater than 24 per minute
›Oxygen saturation less than 92 percent on room air
›Temperature 38.0 C or higher
Limb threat red flags
›Limb threat
›Absent distal pulses
›Cool pale foot
›Severe pain out of proportion
›Pain with passive toe stretch
›Rapidly increasing swelling or tense compartments
›New motor weakness
Infection and necrotizing infection red flags
›Infection red flags
›Fever with hot swollen ankle
›Immunocompromised state with acute monoarthritis
›Rapidly spreading erythema
›Skin bullae
›Crepitus
›Systemic toxicity
03Medications/meds19
Current medications and recent changes
›Medication inventory
›Prescription analgesics
›OTC NSAIDs
›Acetaminophen exposure
›Recent antibiotics
›Recent systemic corticosteroids
›Recent intraarticular injection
Antithrombotic and bleeding risk medications
›Bleeding risk medications
›Warfarin
›DOACs
›Antiplatelets
›NSAID plus anticoagulant combination risk
High risk interactions relevant to ankle pain care
›Interaction and contraindication checks
›NSAID contraindications
›Chronic kidney disease risk
›Heart failure risk
›Pregnancy NSAID trimester cautions
›Colchicine interactions
›QT prolonging medication overlap if antiemetics used
04Diet/diet14
Hydration and recent intake
›Intake pattern
›Low oral intake due to illness
›Dehydration risk
›Recent vomiting or diarrhea
›High sodium intake with edema tendency
Gout relevant exposures
›Purine and alcohol exposure
›Recent binge alcohol
›Beer exposure
›High purine meals
›Sugary beverage exposure
Bone health nutrition
›Bone health
›Low calcium intake pattern
›Low vitamin D intake pattern
›Eating disorder risk pattern
05Review of Systems/ros19
Musculoskeletal
›MSK symptoms
›Knee pain
›Hip pain
›Back pain
›Other joint swelling
›Morning stiffness
Neurologic and vascular
›Neurovascular symptoms
›Numbness
›Tingling
›Weakness
›Color change
›Claudication symptoms
Infectious and systemic
›Systemic symptoms
›Fever
›Chills
›Night sweats
›Unintentional weight loss
›Recent skin infection
›Recent sore throat or diarrhea
06Collateral History and Family History/chafh14
Collateral source and reliability
›Collateral
›Witnessed mechanism details
›Baseline mobility confirmation
›Medication list confirmation
Family history relevant to ankle pain
›Family history
›Gout
›Inflammatory arthritis
›Early osteoporosis or fragility fractures
›Bleeding disorders
Exposure and household context
›Exposure context
›Sick contacts
›Recent travel
›Pet or animal exposure
›Support for crutch use and safe ambulation
07Risk Factors/rf26
Trauma and fracture risk
›Fracture risk
›Age over 65 years
›Known osteoporosis
›Prior fragility fracture
›Chronic glucocorticoid use
›High energy mechanism
›Intoxication at time of injury
Infection risk for septic arthritis
›Septic arthritis risk
›Diabetes mellitus (E11.9)
›Immunosuppression
›Recent bacteremia
›Skin breakdown near joint
›Recent joint injection
›IV drug use
Thrombosis and vascular risk
›Vascular and thrombosis risk
›Recent immobilization
›Prior venous thromboembolism
›Active malignancy
›Peripheral arterial disease (I73.9)
›Smoking
Tendon and ligament injury risk
›Soft tissue injury risk
›Prior ankle sprain
›Hyperlaxity
›High demand sport
›Poor footwear support
›Neuropathy (E11.40)
08Differential Diagnosis/ddx49
Life threatening
›Life threatening and limb threatening
›Acute compartment syndrome
›Disproportionate pain
›Pain with passive stretch
›Tense compartments
›Open fracture or fracture dislocation
›Wound communicating with joint or fracture
›Gross deformity
›Septic arthritis (M00.9)
›Hot swollen joint
›Fever or systemic toxicity
›Necrotizing soft tissue infection
›Rapid progression
›Severe pain out of proportion
›Acute limb ischemia (I74.9)
›Pain with pulselessness
›Pallor and coolness
Common
›Common causes
›Lateral ankle sprain
›Inversion mechanism
›Lateral swelling and ecchymosis
›Ankle fracture
›Bony tenderness
›Inability to bear weight
›Achilles tendinopathy
›Posterior heel pain
›Pain with plantarflexion loading
›Posterior tibial tendon dysfunction
›Medial pain
›Arch collapse tendency
›Gout flare (M10.9)
›Sudden severe monoarthritis
›Prior flares
Less common
›Less common and mimics
›Syndesmotic injury high ankle sprain
›External rotation mechanism
›Pain above ankle mortise
›Osteochondral lesion of talus
›Persistent pain after sprain
›Mechanical symptoms
›Stress fracture
›Overuse history
›Focal bony tenderness
›CPPD disease (M11.20)
›Acute hot swollen joint in older adult
›Chondrocalcinosis on imaging
›Deep vein thrombosis (I82.409)
›Calf swelling
›Risk factors for thrombosis
09Past Medical History/pmh17
Relevant chronic conditions
›Chronic conditions
›Diabetes mellitus (E11.9)
›Chronic kidney disease (N18.9)
›Peripheral vascular disease (I73.9)
›Rheumatoid arthritis (M06.9)
›Gout (M10.9)
›Neuropathy
Prior injuries and procedures
›Prior ankle history
›Prior sprains with instability
›Prior ankle fracture
›Prior tendon rupture
›Prior surgery with hardware
Baseline functional status
›Baseline function
›Baseline gait and endurance
›Baseline need for assistive device
›Baseline anticoagulation indication
›Baseline fall risk
10Physical Exam/exam30
General and vital signs
›General and vitals
›Appearance toxic or nontoxic
›Fever presence
›Hemodynamic stability
›Pain behavior disproportionate concern
Local ankle and foot exam
›Local exam
›Inspection for deformity
›Swelling distribution
›Ecchymosis pattern
›Skin integrity and open wounds
›Point tenderness mapping
›Range of motion active and passive
Neurovascular and compartment screening
›Neurovascular
›Dorsalis pedis pulse
›Posterior tibial pulse
›Capillary refill
›Sensation plantar and dorsal
›Motor toe extension and flexion
›Compartment firmness and pain with passive stretch
Proximal and adjacent joint exam
›Adjacent joint screening
›Proximal fibula tenderness
›Knee effusion or tenderness
›Midfoot tenderness
›Achilles tendon palpation
›Calf tenderness and asymmetry
Gait and function
›Functional testing
›Ability to bear weight for 4 steps
›Antalgic gait severity
›Single leg stance tolerance
›Ability to perform heel raise
11Lab Studies/labs20
Core labs when indicated
›Targeted labs
›CBC if infection concern
›CRP if septic arthritis concern
›ESR if inflammatory arthritis concern
›Blood cultures if febrile or septic
Metabolic and medication safety labs
›Medication safety
›Creatinine before NSAID escalation in risk patients
›Liver enzymes if acetaminophen overuse concern
›INR if warfarin use with bleeding concern
Arthrocentesis studies for suspected septic arthritis
›Synovial fluid studies
›Cell count with differential
›Gram stain
›Culture
›Crystal analysis
›Glucose and protein local protocol dependent
Pitfalls and limitations
›Interpretation limitations
›Serum uric acid may be normal during acute gout flare
›Normal WBC does not exclude septic arthritis
›CRP and ESR support inflammation but are nonspecific
›Antibiotics before aspiration may reduce culture yield
12Imaging/img39
Scoring Systems
›Decision rules for radiography
›Ottawa Ankle Rules
›Ankle radiographs if pain in malleolar zone and any of
›Bone tenderness posterior edge or tip of lateral malleolus
›Bone tenderness posterior edge or tip of medial malleolus
›Inability to bear weight for 4 steps immediately and in ED
›Reported sensitivity near 100 percent for clinically significant fracture in validation studies
›Ottawa Foot Rules
›Foot radiographs if pain in midfoot zone and any of
›Bone tenderness at base of fifth metatarsal
›Bone tenderness at navicular
›Inability to bear weight for 4 steps immediately and in ED
MRI
›MRI ankle
›Indications
›Persistent pain with normal radiographs
›Suspected osteochondral lesion
›Suspected tendon rupture
›Suspected syndesmotic injury with instability
›Contraindications and cautions
›Non MRI compatible implanted device
›Severe claustrophobia
›Gadolinium use caution in severe CKD
CT
›CT ankle
›Indications
›Complex fracture definition
›Suspected occult fracture with high pretest probability
›Preoperative planning
›Cautions
›Radiation exposure
›Contrast nephropathy risk if contrast used
Ultrasound
›Ultrasound and POCUS
›Uses
›Joint effusion detection and guided arthrocentesis
›Achilles tendon rupture assessment
›Tendon subluxation assessment
›DVT evaluation when calf symptoms present
›Pitfalls
›Effusion does not distinguish septic from inflammatory arthritis
›Operator dependence for tendon findings
13Special Tests/spec14
Bedside ligament and syndesmosis maneuvers
›Ankle instability maneuvers
›Anterior drawer test
›Talar tilt test
›Squeeze test for syndesmosis
›External rotation stress test
Tendon integrity maneuvers
›Tendon tests
›Thompson test for Achilles rupture
›Single leg heel raise for Achilles function
›Posterior tibial tendon single heel rise test
Procedural diagnostics
›Procedural tests
›Arthrocentesis for hot swollen ankle
›Bedside Doppler pulse assessment if weak pulses
›Ankle brachial index if arterial insufficiency concern
›Compartment pressure measurement if compartment syndrome concern
14ECG/ecg9
When ECG is relevant in ankle pain presentations
›ECG indications
›Syncope associated with fall or injury
›Palpitations preceding injury
›Chest pain or dyspnea with calf swelling concern
High risk ECG patterns that change disposition
›ECG red flags
›Ischemic changes
›Ventricular arrhythmia
›High grade AV block
›Prolonged QT with planned QT prolonging medications
15Assessment/ax16
Problem representation and severity
›Synthesis
›Traumatic ankle pain with suspected sprain
›Traumatic ankle pain with suspected fracture
›Atraumatic hot swollen ankle concerning for septic arthritis versus crystal arthritis
›Posterior ankle pain concerning for Achilles tendon injury
Risk stratification
›Risk stratification
›Neurovascularly intact versus compromised
›Open injury versus closed injury
›Weight bearing ability
›High energy mechanism versus low energy mechanism
Key complications to rule out
›Cannot miss complications
›Compartment syndrome
›Syndesmotic instability
›Maisonneuve pattern with proximal fibula injury
›Osteochondral injury after sprain
›Septic arthritis in atraumatic monoarthritis
16Plan/plan41
Analgesia and symptom control
›Pain control
›Acetaminophen PO 1000 mg every 6 hours as needed
›Maximum 3000 mg per 24 hours typical
›Lower maximum with liver disease or heavy alcohol use
›Ibuprofen PO 400 mg every 6 to 8 hours as needed
›Avoid with GI bleed history
›Avoid with advanced CKD
›Avoid with decompensated heart failure
›Topical diclofenac gel local protocol dependent
›Prefer for older adults with NSAID risk
›Avoid on broken skin
Immobilization and functional support
›Support
›Compression wrap if mild sprain
›Air stirrup brace for lateral sprain
›Walking boot for severe sprain or occult fracture concern
›Crutches with protected weight bearing as tolerated
Diagnostic sequencing
›Diagnostic plan
›Radiographs if Ottawa rules positive or clinical concern
›CT if radiographs show complex fracture or high suspicion occult fracture
›MRI if persistent pain with negative radiographs and concern for osteochondral or ligament injury
›Arthrocentesis before antibiotics if septic arthritis suspected and patient stable
Condition specific treatment pathways
›Pathway selection
›Suspected sprain
›Early protected mobilization when stable
›Physical therapy referral for proprioception and strength
›Suspected fracture
›Immobilize and keep non weight bearing until stability confirmed
›Orthopedics consult if unstable or displaced fracture
›Suspected septic arthritis
›Immediate orthopedic consultation
›IV antibiotics after cultures and aspiration when feasible
›Suspected gout
›NSAID if low risk
›Colchicine PO 1.2 mg once then 0.6 mg 1 hour later
›Then 0.6 mg once or twice daily as tolerated
›Avoid or reduce dose in CKD and with interacting drugs
Reassessment loop
›Reassessment
›Repeat neurovascular exam after splinting
›Repeat pain score within 30 to 60 minutes after analgesia
›Recheck swelling progression before discharge
›Escalate if increasing pain out of proportion or new neurologic deficit
17Disposition/dispo20
ICU and high acuity criteria
›High acuity disposition
›Septic shock or sepsis criteria
›Limb ischemia signs
›Suspected compartment syndrome
›Open fracture with hemodynamic instability
Inpatient admission criteria
›Admission indications
›Septic arthritis requiring operative management
›Unstable fracture requiring urgent surgery
›Inability to ambulate with unsafe home situation
›Uncontrolled pain despite ED therapy
Observation pathway criteria
›Observation
›Severe sprain with need for mobility training
›Possible occult fracture needing serial exam and follow up imaging plan
›Atraumatic monoarthritis awaiting synovial results and clinical trend
Discharge criteria and follow up
›Discharge
›Neurovascularly intact
›Pain controlled on oral regimen
›Safe ambulation plan with brace or crutches
›Clear follow up plan within 3 to 7 days for fracture concern
›Sports medicine or physiotherapy follow up within 1 to 2 weeks for sprain rehab
18Discharge Instructions/di14
Copy discharge instructions
›Patient facing instructions
›Your ankle pain is most consistent with a sprain or soft tissue injury unless imaging showed a fracture
›Use the brace or boot as instructed and use crutches if needed to limit pain with walking
›Elevate the ankle when resting and use compression if advised
›Use acetaminophen and or ibuprofen as directed unless you were told to avoid them
›Do not take ibuprofen or other NSAIDs if you have kidney disease severe stomach ulcer bleeding or are on blood thinners unless your clinician said it is safe
›Return to the emergency department urgently if
›Your foot becomes cold pale blue or numb
›You cannot move your toes
›Pain rapidly worsens or pain is severe with gentle toe movement
›You develop fever or the ankle becomes hot very red and more swollen
›You notice new drainage from a wound
›Follow up with your clinician or a fracture clinic within the recommended time window
›Do not drive if you cannot safely brake or if you are taking sedating pain medication
19References/r6
Guidelines and decision tools
›Key sources
›Stiell IG et al Decision rules for the use of radiography in acute ankle injuries 1993
›Martin RL et al JOSPT Clinical Practice Guideline Lateral Ankle Ligament Sprains Revision 2021
›Ravn C et al Guideline for management of septic arthritis in native joints SANJO 2023
›IDSA and PIDS Clinical Practice Guideline Acute Bacterial Arthritis in Pediatrics 2023
Evidence & Review
Reviewed by SymptomDx Medical Team·Last reviewed
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.