What are the indications for applying the Ottawa ankle rule in patients of all ages?

Ottawa Ankle Rules: Age Criteria and Indications

Validated Age Range

The Ottawa Ankle Rules are validated for patients 5 years of age and older, and should not be applied to children younger than 5 years. 1, 2

• The rules demonstrate 92-100% sensitivity for detecting ankle fractures in patients ≥5 years of age 2
• No upper age limit exists for application of the rules, though specificity decreases significantly in geriatric populations 3

Core Indications for Radiography

Radiographs are indicated when there is pain in the malleolar zone AND any of the following 1, 2:

Ankle Rules

• Bone tenderness along the distal 6 cm of the posterior edge or tip of either the medial or lateral malleolus 2
• Inability to bear weight both immediately after injury and for four steps in the emergency department 1, 2

Foot Rules

• Point bone tenderness at the navicular bone 2
• Point bone tenderness at the base of the fifth metatarsal 2
• Inability to bear weight both immediately after injury and for four steps in the emergency department 2

Critical Exclusionary Criteria

The Ottawa Ankle Rules should NOT be used in the following situations 1, 2:

• Children under 5 years of age 2
• Penetrating trauma 2
• Pregnancy 2
• Injuries more than 10 days old 2
• Return visits for the same injury 2
• Polytrauma 2
• Altered sensorium or neurologic abnormality affecting the foot 2
• Underlying bone disease 2
• Obvious deformity 4

When exclusionary criteria are present, radiographs should be obtained regardless of Ottawa Ankle Rules findings 1

Age-Specific Considerations

Geriatric Population (≥65 years)

Consider a lower threshold for imaging in patients 65 years and older, as specificity drops significantly in this age group. 3

• Specificity decreases from 60% in non-geriatric patients to 33% in geriatric patients 3
• Some evidence suggests mandating imaging for all patients ≥65 years with ankle pain to achieve 99% sensitivity 3
• The American College of Radiology recommends considering age-specific modifications for elderly patients 2

Pediatric Population (5-12 years)

• The rules maintain excellent sensitivity when applied by physicians in children 5-17 years 5
• Some guidelines suggest radiographs may be beneficial for children 5-12 years despite lack of clinical symptoms 2
• When applied by non-physician providers, sensitivity remains very good (88-100%) but inter-observer reliability is lower 5

Clinical Performance Across Ages

The Ottawa Ankle Rules achieve 96.8-100% sensitivity for detecting clinically significant fractures, with negative predictive values of 97-99%. 1, 2

• Specificity ranges from 25-46% for ankle rules and is lower in older populations 1, 3
• The rules reduce unnecessary radiography by approximately 30-35% 2, 4
• Adding swelling as a criterion increases sensitivity to 100% for the malleolar zone 1, 2

Common Pitfalls

• Do not apply the rules to patients under 5 years - they have not been validated in this population and may miss clinically significant fractures 2
• Ensure proper assessment of all criteria before ruling out imaging need 2
• Be cautious in geriatric patients - consider a lower threshold for imaging given decreased specificity 3
• The rules do not address metatarsal head, toe injuries, or penetrating trauma with concern for foreign body 2