Ankle Sprain

Ankle sprains are among the most common sports injuries. Inversion injuries cause 85% of ankle sprains, with damage most commonly at the lateral collateral ligament complex. Only 15% involve the medially located deltoid ligament. Severe pain and swelling may warrant immobilization and orthopedic follow-up to assess for joint stability and to protect against another insult during the healing phase.

Fractures about the ankle tend to occur more frequently than sprains in the young child and preadolescent because the ligaments in this age group are much stronger than the physes or even the bone, leading to avulsion fractures and fractures through the growth plate. In the skeletally mature adolescent or adult, sprains are more likely to result from ankle trauma because the physes have fused and the bone has increased strength.

A young child who has pain and swelling over a physis should be presumed to have at least a Salter-Harris type I fracture and should be immobilized in a plaster splint with orthopedic follow-up. The skeletally mature female who has mild pain but whose radiographs are normal can be managed with compression and crutches. 

Adolescents who have fused physes are skeletally mature. If they sustain a sprain to the lateral ligaments of the ankle, such as the girl described in the vignette, they are at low risk for an occult fracture, obviating the need for either a cast or orthopedic consultation. Moderate-to-marked swelling and tenderness over the injury site accompanies a significant sprain. The R-I-C-E mnemonic delineates the important components of therapy for a sprain: Rest, Ice, Compression, and Elevation. Ice packs should be applied for at least 20 minutes, and frequent reapplication is recommended for the first 36 to 48 hours after the injury. Heat is contraindicated during the acute stage of the injury. Range of motion exercises can shorten the period of disability, but vigorous physical therapy with weight bearing is not helpful or necessary.

References:
Anderson AC. Injury-ankle. In: Fleisher GR, Ludwig S, eds. Textbook of
Pediatric Emergency Medicine. 4th ed. Philadelphia, Pa: Lippincott
Williams & Wilkins; 2000:321-329
Huurman WW, Ginsburg GM. Musculoskeletal injury in children. Pediatr
Rev. 1997;18:429-440
Staheli LT. Sports. In: Fundamentals of Pediatric Orthopedics. 2nd ed.
Philadelphia, Pa: Lippincott-Raven; 1998:111-128