Basics
Description
- Injuries to ligamentous supports of the ankle
- Ankle joint is a hinge joint composed of the tibia, fibula, and talus.
- Injuries may range from stretching with microscopic damage (grade I) to partial disruption (grade II) to complete disruption (grade III).
Etiology
- Forced inversion or eversion of the ankle
- Forceful collisions
- 85-90% of ankle sprains involve lateral ligaments:
- Anterior talofibular (ATFL)
- Posterior talofibular (PTFL)
- Calcaneofibular (CFL)
- Usually the result of an inversion injury
- The ATFL is the most commonly injured.
- If the ankle is injured in a neutral position, the CFL is often injured.
- The PTFL is rarely injured alone.
- Injury to the deltoid ligament (connecting the medial malleolus to the talus and navicular bones) is usually the result of an eversion injury:
- Often associated with avulsion at the medial malleolus or talar insertion
- Rarely found as an isolated injury
- Suspect associated lateral malleolus fracture or fracture of the proximal fibula (Maisonneuve fracture).
- Syndesmosis sprains (injury to the tibiofibular ligaments or the interosseous ligament of the leg):
- Occur most commonly in collision sports
- Syndesmosis injuries ("high ankle sprains") have a higher morbidity and potential for long-term complications.
- Children <10 yr with traumatic ankle pain and no radiologic evidence of fracture most likely have a Salter-Harris I fracture.
- The ligaments are actually stronger than the open epiphysis.
Diagnosis
Signs and Symptoms
History
History may predict the type of injury found and should include:
- Time of injury
- Mechanism
- The presence of a "pop" or "crack"
- History of previous trauma
- Relevant medical conditions (e.g., bone or joint disease)
- Treatments attempted prior to arrival
- Ability to bear weight subsequent to the injury at scene and ED
Physical Exam
- Aimed at detecting joint instability and any associated injuries:
- Note the presence or absence of bony tenderness at posterior edge of medial and lateral malleoli as well as at the base of the 5th metatarsal.
- Document neurovascular status distal to the injury.
- Assess range of motion and compare it with the uninjured side.
- Stress testing in the ED is often limited by pain and may impair detection of ligament injury.
- The squeeze test helps identify syndesmosis injuries:
- Squeeze tibia and fibula together at the midcalf; pain felt in the ankle indicates a positive test.
Essential Workup
- The Ottawa Ankle Rules, a selective strategy for obtaining ankle radiographs in adults, suggest that foot or ankle radiographs are unnecessary except when any of the following are present:
- Bony tenderness at the posterior edge of the distal 6 cm or tip of either malleolus
- Bony tenderness along the base of the 5th metatarsal or navicular bone
- Inability to take 4 unassisted steps both immediately after the injury and in the ED
- The rules have been prospectively validated by the original authors as well as independently by groups in the US, the UK, France, and other countries.
Diagnosis Tests & Interpretation
Imaging
- Ankle injuries should be radiographed if there is concern for fracture.
- Stress radiographs are rarely useful in the ED and should not be routinely ordered unless requested by a consultant.
Differential Diagnosis
- Ankle fracture (lateral, medial, or posterior malleolus) or dislocation
- Achilles tendon injury
- Maisonneuve fracture
- Os trigonum fracture
- 5th metatarsal fracture (Jones fracture)
- Transchondral talar dome fracture
- Peroneal tendon dislocation or injury
Treatment
Pre-Hospital
Immobilize ankle as necessary.
Initial Stabilization/Therapy
- Prevent further injury; avoid weight bearing if painful.
- RICE (rest, ice, compression, elevation)
Ed Treatment/Procedures
- The goal of treatment is reduction of pain and return to normal activity without long-term pain or joint laxity.
- Existing evidence supports early mobilization and functional treatment:
- Unstable ankles (i.e., grade III) or those with severe pain may benefit from brief immobilization followed by early return to functional treatment.
- Grade I or II sprains can be treated with functional support (elastic bandage, air splint, gel splint, etc.):
- Recent evidence suggests an elastic bandage dressing coupled with an air stirrup splint is superior to other forms of immobilization.
- Grade III sprains can be treated by immobilization (sugar tong with posterior splint or elastic bandage dressing coupled with air stirrup splint) and early orthopedic consultation or referral.
- Crutches may be needed initially for comfort, but encourage weight bearing as tolerated for grades I and II.
- Once acute pain and swelling have resolved, strengthening exercises and proprioceptive training (e.g., balance board, small circle walking) improve ankle strength and function and prevent reinjury.
- Full sports activities may be resumed only when running and turning are pain free.
- Ankle taping, air splints, or gel splints reduce the risk of recurrent injury in high-risk sports such as basketball, volleyball, soccer, and running.
Medication
- NSAIDs are useful in treating acute pain:
- Ibuprofen: 800 mg (peds: 5-10 mg/kg) PO TID
- Topical NSAIDs have been shown to control pain and shorten healing time with acute ankle sprain:
- Diclofenac sodium 1% gel: Apply 4g to affected area QID
- Narcotic analgesics may be required for severe pain.
Follow-Up
Disposition
Admission Criteria
An isolated ankle sprain should not require admission.
Discharge Criteria
An isolated ankle sprain may be safely discharged from the ED with appropriate treatment, prescriptions, aftercare instructions, and referrals.
Issues for Referral
Patient copies of any radiographs obtained may facilitate early follow-up.
Follow-Up Recommendations
- Patients with grade I and II sprains should be instructed to follow up with the primary care physician in 1-2 wk.
- Patients with grade III sprains and syndesmosis injuries should be referred to an orthopedic surgeon or sports medicine specialist within 7-10 days.
Pearls and Pitfalls
- The Ottawa Ankle Rules may decrease the need for radiographs.
- Immobilization with an elastic bandage dressing coupled with an air stirrup splint followed by early functional therapy may shorten healing time.
Additional Reading
- Beynnon BD, Renstr ¶m PA, Haugh L, et al. A prospective, randomized clinical investigation of the treatment of 1st-time ankle sprains. Am J Sports Med. 2006;35:1401-1402.
- Ho K, Abu-Laban RB. Ankle and foot. In: Marx JA, Hockberger RS, Walls RM, et al., eds. Rosens Emergency Medicine: Concepts and Clinical Practice, 7th ed. Philadelphia, PA: Mosby/Elsevier; 2010:670-697.
- Jones MH, Amendola AS. Acute treatment of inversion ankle sprains: Immobilization versus functional treatment. Clin Orthop Relat Res. 2007;455:169-172.
- Predel HG, Hamelsky S, Gold M, et al. Efficacy and safety of diclofenac diethylamine 2.32% gel in acute ankle sprain. Med Sci Sports Exerc. 2012;44(9):1629-1636.
- Stiell IG, McKnight RD, Greenberg GH, et al. Decision rules for use of radiography in acute ankle injuries: Refinement and prospective validation. JAMA. 1993;269:1127-1132.
Codes
ICD9
- 845.00 Sprain of ankle, unspecified site
- 845.02 Sprain of calcaneofibular (ligament) of ankle
- 845.09 Other sprains and strains of ankle
- 845.03 Sprain of tibiofibular (ligament), distal of ankle
- 845.01 Sprain of deltoid (ligament), ankle
- 845.0 Ankle sprain
ICD10
- S93.409A Sprain of unsp ligament of unspecified ankle, init encntr
- S93.419A Sprain of calcaneofibular ligament of unsp ankle, init
- S93.499A Sprain of other ligament of unspecified ankle, init encntr
- S93.429A Sprain of deltoid ligament of unspecified ankle, init encntr
- S93.439A Sprain of tibiofibular ligament of unsp ankle, init encntr
SNOMED
- 44465007 sprain of ankle (disorder)
- 209532000 Sprain, ankle joint, lateral (disorder)
- 209531007 Sprain, ankle joint, medial (disorder)
- 24730004 Sprain of calcaneofibular ligament
- 74383007 Sprain of distal tibiofibular ligament