Lateral ankle sprains are one of the most common in sports medicine. Considering the sprains in general, they represent an 85% of the ankle lesions. The incidence in high performance athletes range from 16 to 21%. It is estimated that 10,000 to 25,000 peoples suffers a lateral ankle sprain per hour in the United States. The objective of the treatment is to normalize the articular function and allow the patient to return to his or her normal physical activities. Platelet rich plasma is a simple of autologous blood with concentrations of platelets above baseline values. This is rich in platelet derived growth factor which stimulates cell replication, angiogenesis, transforming growth factor B1, fibroblast growth factor, epidermal growth factor, and insulin like growth factor. The risks of its applications are minimal and are usually involved with allergic reactions to other medications that are applied in combination with the platelet-rich plasma.

To establish that the use of platelet rich plasma and immobilization with a short leg cast in acute lateral ankle sprains will enhance an early recovery in comparison with just immobilization with the cast.

Lateral ankle sprains are one of the most common in sports medicine. Considering the sprains in general, they represent an 85% of the ankle lesions. The incidence in high performance athletes range form 16 to 21%. It is estimated that 10,000 to 25,000 suffers a lateral ankle sprain per hour in the United States. The objective of the treatment is to normalize the articular function and allow the patient to return to his or her normal physical activities.

The lateral ligamentous complex of the ankle consists of three ligaments: the anterior talofibular, the calcaneofibular, and the posterior talofibular. The anterior talofibular ligament is the most affected. The patient describes a tear sensation in the ankle after an acute inversion of it. The injuries occur during physical activities as running. The patients presents with pain, swelling and tenderness over the affected ligaments. The proper diagnosis of the sprain includes anteroposterior, lateral and mortise view X rays of the affected ankle; if there is any suspicion of instability of the ankle, the physician shall order a Magnetic Resonance Image (MRI) to evaluate the ligaments.

Lateral ankle sprains have been classified by numerous methods. By anatomic site, lateral ankle sprains can be classified as grade I: anterior talofibular sprain, grade II: anterior talofibular and calcaneofibular sprains, and grade III: anterior talofibular, calcaneofibular and posterior talofibular sprains. By clinical system the sprains can be classified as mild with minimal function loss, no limp, minimal swelling, tenderness, pain with reproduction of mechanism of injury; moderate with moderate functional loss, unable to rise on toes, limp when walking, localized swelling; and severe with diffuse tenderness, patient use crouches for ambulation.

Conventional treatment for lateral ankle sprains is conservative, but a 32% of the patients have chronic complications as edema, pain, and ankle instability. The treatment for acute sprains have good to excellent results. Ankle dorsiflexion allows the fibers of the affected ligament to approximate and gives stability of the ankle. The first phase of the treatment requires rest, immobilization, compression with orthesis, and the use of non steroidal anti-inflammatory drug.

Platelet rich plasma is a sample of autologous blood with concentrations of platelets above baseline values, is rich in platelet derived growth factor which stimulates cell replication, angiogenesis, transforming growth factor beta-1, fibroblast growth factor, epidermal growth factor, and insulin like growth factor. The risks of its applications are minimal and are usually involved with allergic reactions to other medications that are applied in combination with the platelet rich plasma.

Purpose To establish that the use of platelet rich plasma and immobilization with a short leg cast in acute lateral ankle sprains will enhance an early recovery in comparison with just immobilization with the cast.

Inclusion Criteria:

• Acute lateral ankle sprain with no more of 48 hours of evolution
• First time lateral ankle sprain
• Grade 2 or 3

Exclusion Criteria:

• Associated pathologies like diabetes mellitus, osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, neurologic or psychiatric issues
• Pregnant women
• Previous surgery of the foot and ankle
• Blood dyscrasias

All included patients were evaluated at 24 weeks after the protocol interventions were initiated.

The diagnosis of Lateral Ankle Sprain was based on a clinical classification. We didn't use an Ultrasound scan, to perform the application of the Platelet Rich Plasma, or to assess morphologically the affected area before and after the treatment

Application of autologous platelet-rich plasma