Sprains

A sprain in an adult is a tear, or stretch, of a ligament:

• Most common around the ankle though may occur in the shoulder, knee, wrist or fingers
• Less common in children because the developing child’s ligaments are very strong and relatively lax
• Trauma tends to cause damage at the bony attachment of the ligament which is often around the physeal plate area

Learning bite

The Ottawa ankle rules, used in adults to distinguish sprains from fractures, apply to children down to the age of 5 years and have been validated for such use in an ED setting [5].

The Ottawa ankle rules

Ankle X-ray is only required if there is any pain in the malleolar zone and any one of the following:

• Bone tenderness along the distal 6 cm of the posterior edge of the tibia or tip of the medial malleolus, OR
• Bone tenderness along the distal 6 cm of the posterior edge of the fibula or tip of the lateral malleolus, OR
• An inability to bear weight both immediately and in the emergency department for four steps.
• Additionally, the Ottawa ankle rules indicate whether a foot X-ray series is required. It states that it is indicated if there is any pain in the midfoot zone and any one of the following:
• Bone tenderness at the base of the fifth metatarsal (for foot injuries), OR
• Bone tenderness at the navicular bone (for foot injuries), OR
• An inability to bear weight both immediately and in the emergency department for four steps.

Certain groups are excluded, in particular pregnant women, and those with diminished ability to follow the test (for example due to head injury or intoxication). Several studies strongly support the use of the Ottawa Ankle Rules in children over 6 (98.5% sensitivity);[2] however, their usefulness in younger children has not yet been thoroughly examined.