Ankle Sprains

Kenneth G. Venos, M.D.

The most common injury in sports involves a sprain of the ankle ligaments located on the outside or lateral aspect of the foot and ankle. Approximately 27,000 ankle sprains occur daily in the United states. Despite the high incidence of ankle sprains, there is a vast variety in treatment recommendations and treatment plans.  The literature suggests that 80 to 90% of all ankle sprains will heal without surgery and a successful outcome. Unfortunately, 20 to 40% of patient’s who have complete tears of the lateral ligamentous structures of the ankle (the outside of the ankle) will have enough pain and stiffness to limit their activities significantly.

The ligament most frequently sprained is the anterior talofibular ligament (ATFL) and is actually the most frequently injured ligament in the body. In addition to the lateral ligamentous complex, there is a distal tibiofibular syndesmosis between the tibia or shin bone and fibula which is prone to injury and diagnosed as a high ankle sprain.

The medial collateral or deltoid ligament is a fan-shaped ligament composed of a deep and superficial layer that stabilizes the inside or medial aspect of the ankle.

Third degree sprain or rupture of ankle ligamentous structures can lead to mechanical instability. The muscles crossing the ankle joint can compensate for an unstable ligament structure and provide a functionally stable ankle in many incidences. Conservative, nonsurgical ankle rehabilitation attempts to improve the muscle function especially of the peroneal muscles and tendons on the outside of the ankle and can be augmented by taping, bracing, strengthening and proprioceptive training (learning where the foot and ankle are in space without actually looking at them).

When an ankle injury occurs, it is important to note exactly where the ankle hurts, the position of the foot and ankle at the time of the injury and the direction of the force applied to the extremity. Point tenderness is usually very localized and when it occurs, x-rays should be taken.

Early examination before swelling occurs is important to help understand which structures were injured. Often times, injuries involving the midfoot, forefoot or the peroneal tendons are overlooked. Ligamentous stress testing in the early stages of the examination are often unproductive as pain limits the ability of the patient to cooperate. stress x- rays can be helpful at that point.

Classification of soft tissue injuries or sprains of the ankle is somewhat controversial. Type I sprains are commonly described as a mild injury to the lateral ligament complex with minimal swelling and tenderness, no functional loss of activity and a mechanically stable joint. Normal activity is the norm but somewhat painful.

A grade 2 injury is described as a moderate ankle injury. In this case, there is usually difficulty weightbearing, tenderness over the outside of the ankle, swelling and bruising. Activity is significantly limited. The ankle often is slightly unstable.

Grade 3 ankle sprains are as a result of severe double ligament injury on the outside of the ankle and weightbearing is usually not possible because of pain, there is marked swelling, bruising and tenderness.

A complete disruption of the syndesmosis between the distal tibia or shin bone and fibula can occur. This is described as a high ankle sprain and can lead to gross instability of the ankle and arthritis. Isolated deltoid injuries are rare and often times are associated with syndesmotic injuries.

Treatment of Acute Ankle Injuries

Most ankle sprains are initially treated with the conservative PRICE protocol. This includes protection, rest, ice, compression and elevation. This is to help reduce the swelling and minimize pain. Anti-inflammatories are indicated to help reduce tissue swelling in the early injury phase. Mechanically stable grade 1 and grade 2 ankle sprains may improve with short term immobilization such as a rockerbottom ankle/foot orthosis or an ankle lacer. During this protection period, range of motion exercises are gradually progressed as is weightbearing and strengthening. Eventually, agility training and endurance training are added. Crutch use is suggested until there is no significant limp involved with walking activities. Grade 1 ankle sprains usually recover fully within one to two weeks and grade 2 ankle sprains within two to three weeks although sometimes can take up to six weeks to be pain free and functional. High ankle sprains are often under appreciated and may be the cause for some of the prolonged recovery times. Grade 3 ligament injuries of the ankle are treated differently. Even in aggressive athletes, most research indicates that a nonsurgical early treatment protocol gives the best results.

Short term immobilization in a cast or ankle/foot orthosis is the most accepted treatment protocol in the United States today. Rapid mobilization once pain permits with functional rehabilitation often leads to a satisfactory outcome in 60% or more of these patients.

In cases where the patient has recovered from their initial injury and mechanical and functional instability occur, there are indications for both surgical and nonsurgical treatment. Nonsurgical treatment includes a lateral heel wedge in the shoe, a reinforced counter in the shoe, avoidance of high heels and the use of an ankle/foot orthosis (AFO) and rehabilitation of the ankle muscle groups especially the peroneal muscles on the outside of the ankle.

In the case of failed conservative care and persistent functional and mechanical instability, surgical reconstruction is helpful. In most cases, a modified Brostrom procedure will directly reattach the injured ligaments and ankle range of motion is maintained and stability returned. Suture anchoring techniques have improved vastly over the past decade and have allowed many patients to resume aggressive activities such as ballet and soccer without limitation.

Prevention of ankle sprains, however, is the goal of most orthopedic practices. Ankle sprains are significantly reduced in frequency by an injury prevention program. These programs include break away bases in baseball, a return to natural turf surfaces, a change in cleat pattern on athletic shoes and a conditioning program concentrating on the peroneal muscles and tendons on the outside of the ankle. Bracing, taping and high top shoes are effective forms of preventing inversion injuries to the foot and ankle and lateral ankle sprains. Taping while often preferred by higher level athletes is time consuming, expensive and does not appear to offer superior protection as opposed to well-fitting ankle lacers. Bracing does not appear to interfere with athletic performance and is recommended in athletes who have had prior ankle injuries if they hope to compete safely in the future.

Bibliography

Bennett, WF: Lateral ankle sprains: Part I. Anatomy biomechanics, diagnosis and natural history. Orthopedic Review 1994;23:381.-387

Frey C, Bell J, Tresi L, Kerr R, Freder, K: A comparison of MRI and clinical examination of acute lateral ankle sprains. Foot Ankle Int 1996;17:533-537

Hamilton WG, Thompson FM, Snow SW: The modified Brostrom procedure for lateral ankle instability. 1993;14:1-7

Ottaviani RA, Ashton-Miller JA, Hutchinson C, Wojtysen: What best protects the inverted weightbearing ankle against further inversion? Evertor muscle strength compares figuratively with shoe height, ankle tape, and orthosis. American Journal and Sports Medicine 1996;24:800-809

Pieankowski D, McMorrom, Shappiro R, Caborin DN, Stayton J: Affective ankle stabilizers on athletic performance: A randomized prospective study. American Journal of sport Medicine 1995;24:757-762

Sitler M, Ryan J, Wheeler B,: Efficacy of semi-rigid ankle stabilizer to reduce acute ankle injuries in basketball: A randomized clinical study at West Point. American Journal Sports Medicine 1994;22:454-461

Mizel M, Miller R, Scioli M.: Soft tissue injuries of the ankle. Orthopedic Knowledge Update Foot and Ankle 2 1998;229-242

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