What Is It?
An ankle ligament injury or “sprain “ occurs when a greater than normal stretching force is applied to the ligament, resulting in a range of damage from microscopic tearing (Grade 1) to complete rupture (Grade 3) of the ligament tissue.
Ankle sprains are among the most common of all orthopaedic injuries and are the most frequent type of musculoskeletal injury seen by primary care providers. In excess of 23,000 people each day in the United States seek medical care for ankle sprains. It is reported that the cost of diagnosis and treatment of these injuries is in excess of $ 4 billion USD annually. And 50-75% of patients suffering these injuries report long term morbidity and pain affecting their mobility 6-18 months after injury. Lateral (outside border) ankle sprains account for 85% of all ankle sprains and are typically caused by an inversion (foot rolling inward) mechanism of injury. The recurrence of lateral ankle sprains has been reported to be as high as 80%. Even with appropriate treatment of the acute ankle ligament injury some individuals will have persistent dysfunction (pain, swelling, popping, giving way and inability to perform) and ultimately require surgery for their chronic instability symptoms. Secondary ankle pathology such as osteochondral lesions of the talus and peroneal tendon tears are associated with ankle ligament tears and instability and may also require surgery. Recent studies have shown that approximately 50% of ankle sprains occur during sports or exercise training activities.
Predisposing factors or risk factors for ankle sprain and instability can include poor conditioning, lack of training or experience in the given activity, shortened tendons, structural malalignment of foot or ankle (cavovarus), and loose ligaments from prior sprains.
The ankle joint is composed of 3 bones: tibia, fibula and talus. The lateral ankle complex is composed of 3 ligaments: anterior talofibular, calcaneofibular, and posterior talofibular. The ATFL is the most likely component of the lateral ankle ligament complex to be injured in a lateral ankle sprain. Grade 1 injuries involve a stretch and microscopic tearing. Generally they exhibit minimal swelling with little or no functional loss and no joint instability. And the patient is able to fully bear weight. Grade 2 injuries stretch the ligament with partial macroscopic tearing, moderate to severe swelling, ecchymosis (visible bruising), moderate functional loss, mild to moderate joint instability and difficulty with weight bearing. Grade 3 injuries involve complete rupture of the ligament, immediate and severe swelling, ecchymosis, inability to bear weight and severe instability.
Diagnosis is most accurate when there is an opportunity to have a face to face encounter with the patient for an accurate history, physical exam and possible ancillary studies such as x-rays. During this encounter an important and thorough patient injury specific history is obtained (mechanism of injury, was there a pop?, information regarding prior treatment and prior evaluation). A thorough physical exam is performed assessing location of tenderness, swelling, ecchymosis, manual instability testing. Ancillary studies may be recommended and /or performed: x-rays, stress views, MRI, CT scan.
Initial treatment should consist of “ P.R.I.C.E.S.” – Pain reduction, Rest, Ice, Compression, Elevation, Support. Because NSAIDs (Advil, Aleve, Motrin, etc.) are platelet inhibitors they increase initial bleedingand should be avoided during the first 3-5 days. Tylenol can help with pain and does not increase bleeding. Crutches or another “non weightbearing “method should be used for severe or Grade 3 injuries pending orthopaedic evaluation. Pain reduction is essential along with improvement of any loss of motion, strength and proprioception. Protective devices such as splints or braces are used for up to 3 weeks and criteria for discontinuation include minimal pain or swelling at site of injury. Avoidance of activity that increases pain or swelling and encouraging progression toward full pain free range of motion are important. Those individuals involved in sporting activities have been shown to achieve earlier return to sport and reduced rate of reinjury via supervised physical therapy, prophylactic bracing / taping , and ongoing home or gym based proprioceptive ( balance and coordination) training. The majority of patients will recover and resume former level of activity with minimal or no pain within 8-12 weeks with conservative treatment.
Surgery is reserved for those lateral ankle sprain patients who, after appropriate prolonged conservative treatment, have continued pain and functionally limiting signs and/ or symptoms of chronic instability of the lateral ankle. Such symptoms may include pain, swelling, popping, locking and giving way, inability to perform, recurrent sprains. Surgery can include:
a) anatomic ligament repair (modified Brostrom ligament repair – see below)
b) ligament reconstruction with the patient’s own tendon tissue (tendon autograft) or ligament reconstruction with cadaver tissue (allograft).