The most common type of ankle sprains is one to the lateral ankle. Typically, these are minor and are due to an inversion injury when the ankle is plantarflexed. Sprains are categorized into three grades. Grade I involves no tearing of the ligaments with minimal functional loss, pain, swelling, and ecchymosis. Weight bearing is tolerable. Grade II sprains occur with a partial tear and some loss of functional ability. Grade II sprains tend to be more painful, with swelling, ecchymosis, and difficulty bearing weight. Grade III sprains result from a complete tear, with significant functional loss, pain, swelling, and bruising, and almost a universal inability to bear weight.6 It has been argued, however, that assigning a grade to the sprain is less important than the stability of the joint.24 Joint stability is the primary determinant of a treatment plan for a sprain.
An isolated sprain of the medial deltoid ligament is rare. Medial deltoid ligament tears are usually associated with a fibular fracture or tear of the tibial-fibular syndesmosis from an eversion injury. If there is significant medial malleolus tenderness and swelling, suspect a Maisonneuve fracture of the proximal fibula and fibular shaft. Negative radiographs should suggest syndesmosis tears.
Injuries to the tibiofibular syndesmotic complex are associated with hyperdorsiflexion injuries when the talus moves superiorly and separates the tibia and fibula. This leads to a partial or complete tear of the syndesmosis with complaints of pain just above the talus.
If there is concern for an unsTable ligamentous injury, weight-bearing views of the ankle can help diagnosis—an unsTable ligamentous injury may demonstrate talar shift.
The immediate goals are to decrease pain and swelling and protect ligaments from further injury. The PRICE protocol (protection, rest, ice, compression, elevation) involves elevating the ankle and protecting it with a compressive device along with applying ice and resting up to 72 hours to allow the ligaments to heal.6 There is controversy as to whether or not early immobilization versus functional treatment results in the best outcomes. There is a trend toward favoring early functional treatment over immobilization.7 Patients returned to mobility anywhere between 4.6 and 7.1 days sooner with functional treatment when compared with immobilization.25 Functional treatment usually consists of three phases: (1) PRICE protocol within the first 24 hours of injury; (2) motion and strength exercises to begin within 48 to 72 hours; and (3) endurance training, focused toward specific sports when applicable, and training to improve balance after the second phase begins.6
In patients with a lateral ligament sprain, a sTable joint, and the ability to bear weight, treatment consists of analgesics, an elastic bandage or ankle brace, and no sports involvement, with follow-up in a week if no improvement. Lace-up supports may reduce persistent swelling when compared to elastic bandages or rigid ankle supports.26 For patients who are unable to bear weight but have a sTable joint, provide an ankle brace and crutches and have them follow-up with either their primary care provider or orthopedic surgeon within 1 week for repeat evaluation. Given the trend for early immobilization, functional braces, such as semirigid (e.g., Aircast) and soft, lace-up braces, are commonly used. There is no consensus as to which leads to a more favorable outcome,27 although early rehabilitation of low-grade ankle sprains results in a good outcome.28 Another option is an inflaTable cast boot (also called walking fracture boot or air cast boot) that molds to the foot with inflaTable air bladders. This device can also be used for sTable ankle fractures.
Treat medial ligament sprains with PRICE and early referral to an orthopedic surgeon given the risk for undetected underlying fractures. Consider early orthopedic referral for syndesmotic complex sprains given the expected prolonged recovery time.
Refer patients with an unsTable joint to an orthopedic surgeon after placement of a posterior splint for stabilization. Establish contact with the orthopedic surgeon early because the timing of treatment and follow-up is ultimately at his or her discretion.
There is no consensus as to whether surgery versus conservative treatment results in more favorable outcomes.29 Cryotherapy with ice will help decrease pain and limit swelling and should be applied directly to the ankle or splint but not left on for >20 minutes at a time. Therapeutic ultrasonography is not helpful.5