Prophylaxis reserved for post-pubertal or high-risk
Background
Epidemiology
Frequency and burden
Proportion of ankle fractures
Trimalleolar represents about 7 percent
Highest complication rates among subtypes
Demographic distribution
Young males from sports
Older females from osteoporotic falls
Long-term outcome
30 percent report inferior function at 15 to 22 years
Hardware removal in about 17 percent within 3 years
Complication rates
Infection
Approximately 4.4 percent after ORIF
Higher with diabetes
Thromboembolism
1.6 to 3 percent of operative cases
Preoperative DVT 6.4 percent
Mechanical complications
Approximately 0.4 percent
Post-traumatic arthritis over time
Pathophysiology
Mortise instability
Three-column disruption
Lateral malleolus
Medial malleolus
Posterior malleolus
Talar shift
Medial clear space 4 mm or greater
Loss of congruent contact area
Injury mechanics
Rotational force transmission
Supination-external rotation common
Pronation patterns with syndesmotic injury
Posterior malleolus role
Posterior tibiofibular ligament attachment
Syndesmotic stability contribution
Articular consequence
Step-off and incongruity
Step-off greater than 1 mm raises arthritis risk
Altered joint contact stress
Therapeutic Considerations
Operative principle
Anatomic reduction of articular surface
Minimize step-off
Restore mortise congruity
Soft-tissue respect
Two-stage approach when swelling severe
Reduce wound complications
CT-guided planning
Posterior fragment morphology
Bartonicek classification
Approach and fixation selection
Smaller-fragment fixation trend
Step-off greater than 1 mm threshold
Improved syndesmotic stability
Thromboprophylaxis strategy
LMWH default in operative immobilization
Lower VTE incidence
Continue through non-weight-bearing
Risk-targeted approach
TRiP(cast) score guides selection
Aspirin alternative per PREVENT CLOT
Patient Discharge Instructions
copy discharge instructions
Splint and weight-bearing care
Strict non-weight-bearing on the injured leg
Keep leg elevated above heart level
Do not remove or modify the splint
Wiggle toes frequently to maintain circulation
Pain and swelling control
Ice 20 minutes on and off over the splint
Take pain medication as prescribed
Take blood thinner exactly as prescribed if given
Warning signs to return to ER
Increasing pain despite elevation and medication
Numbness or color change in the toes
Splint becoming too tight or too loose
Fever or drainage from any wound
Calf swelling, warmth, or new shortness of breath
Follow-up plan
Orthopedic surgery appointment within 5 to 7 days
Surgery typically within 1 to 2 weeks once swelling subsides
Full recovery commonly 3 to 6 months
References
Guidelines and key sources
Guideline and consensus sources
ACR Appropriateness Criteria acute trauma to the ankle
American College of Surgeons best practices in orthopedic trauma
Western Trauma Association VTE prevention algorithm
Landmark trials and studies
PREVENT CLOT aspirin versus LMWH for fracture thromboprophylaxis
TRiP(cast) stepped-wedge implementation trial for targeted prophylaxis
Intra-articular hematoma block versus procedural sedation trials
Decision tools and coding
Ottawa Ankle Rules clinical decision rule
ICD-10 S82.853 for displaced trimalleolar fracture
AO/OTA and Bartonicek classification systems
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