History of the Procedure: In the spring of 1862 at the Royal College of Surgeons, John Hilton gave a series of lectures in which he described doing anatomic studies on an ankle sprain to increase his knowledge of the condition (Keith, 1919). Since its development, the radiograph has been used to study ankle sprains. On December 28, 1895, Roentgen presented his findings regarding radiographs to the president of the Wurzburg Physico-Medical Society. The radiograph is still the first-line investigation of ankle sprains, second only to the classic clinical history and physical examination, since radiographs make it possible to distinguish between ligamentous and bony injuries around the ankle. Currently, magnetic resonance imaging allows cartilage and ligament injuries to be diagnosed in ankle injuries.

Problem: Ankle sprains result from force around the ankle that exceeds the tensile limits of the supportive ligaments of the ankle mortice but is less than that which would break the ankle bones. Because the ankle joint is the dynamic link between the leg above and the foot planted on the earth below, it is the site of concentrated forces. The large muscle masses of the lower extremity and the momentum of the body weight are concentrated on the ankle, connected to the foot, which may be firmly planted on the ground. These factors make ankle sprains the second most frequently encountered outpatient orthopedic condition, after chronic back pain, in many orthopedic clinics.

The strongest ankle capsule-ligament complex is the deltoid ligament, which has 2 parts: superficial and deep. The superficial component runs the furthest from the medial malleoli to the medial aspect of the calcaneus, posteriorly. It also attaches to the sustentaculum tali of the talus in the center portion; anteriorly, it joins the spring ligament attaching to the tuberosity of the navicular. The deep portion of the deltoid ligament is short and attaches to the neck, body, and posterior portion of the talus. The greatest mechanical forces across the ankle joint are directed medially in the normal external rotation of the foot in walking and running. This is reflected in the great strength and thickness of the deltoid ligament. Usually, the medial malleolus fractures before the deltoid ligament fails mechanically.

The anterior and posterior capsular ankle ligaments are relatively thin compared to the medial and lateral ankle ligaments. The lateral ankle ligaments are the anterior talofibular ligament, the fibulocalcaneal ligament, and the posterior talofibular ligament. Their attachments and positions are designated by their names.

The ankle joint is a hinged synovial joint with up and down movement primarily (plantarflexion and dorsiflexion). The other joints around the ankle are responsible for the other movements, giving the ankle a total movement comparable to that of a ball and socket. The combined movement in the dorsiflexion and plantarflexion directions is greater than 100°, with bone-on-bone abutment beyond this range that limits and protects the anterior and posterior ankle capsular ligaments from injury. Ankle spurs may occur at any of the bony ligament attachments. An anterior spur observed on lateral radiograph at the neck of the talus, where the anterior ankle capsule attaches, is not uncommon. This occurs due to ossification of hematoma organization associated with anterior ligament sprains.

The lateral ligament of the ankle joint commonly experiences what is typically referred to as an ankle sprain. The lateral ankle ligament has 3 divisions that run from the lateral malleoli to the surrounding bones. The anterior talofibular ligament is most often injured. This ligament runs from the front of the lateral malleoli to the anterolateral aspect of the talus. The foot is not designed to withstand inversion strains because that is not the position in which it normally functions. When the ankle is stressed accidentally in this position, ankle sprain of the anterior talofibular ligament commonly results.

The middle portion of the lateral ankle ligament is called the fibulocalcaneal ligament. It is thicker, cordlike, and stronger than the anterior talofibular ligament. The fibulocalcaneal ligament runs from the tip of the lateral malleolus to the lateral aspect of the calcaneus directly below the fibula. The posterior portion of the lateral ankle ligament is the strongest of the 3 portions of the lateral ankle ligaments and is called the posterior talofibular ligament. It runs almost horizontally from the fossa in the inner aspect of the tip of the lateral malleolus to the posterior tubercle of the talus.

A fifth ankle ligament is rarely sprained because of its great strength. It is a strong syndesmotic ligament with a deep portion between the bones and superficial, anterior, and posterior portions of the ligament. This distal tibiofibular ligament holds the distal tibia and fibular bones together at the ankle joint and maintains the integrity of the ankle mortice. It takes a great amount of force to strain this ligament, which normally does not have much excursion. A tear of this ligament requires surgical treatment because a widened ankle mortice is not tolerated. Severe posttraumatic arthritis of the tibiotalar joint (ankle) can result in a short time if the tear of the distal tibiofibular ligament syndesmosis remains unrecognized and untreated. Tear of this syndesmotic ligament is usually a part of an ankle fracture that needs to be specifically treated. This is not generally true of the other ankle ligaments.

Clinical: History, physical examination, and radiograph are the only investigations typically indicated in an ankle sprain. Many osteochondral lesions heal with standard ankle sprain care.

History of an ankle sprain is usually of an inversion-type twist of the foot followed by pain and swelling. An individual with an ankle sprain can almost always walk on the foot carefully with pain. The ability to walk on the foot usually excludes a fracture and indicates that a sprain has been experienced in an individual with normal local sensation and cerebral function. A person with a third-degree ankle sprain often provides a history of an audible snap followed by pain and swelling.

The physical examination is performed to confirm the diagnosis made based on history and to differentiate an ankle sprain from a fracture. A sprain is usually well defined by pain over the ligament that is sprained. Ankle motion is painful, and the ankle appears to be in the normal anatomic position. The skin is usually intact with local swelling and bruising in third-degree ankle sprains. A positive anterior drawer sign finding on the injured ankle is evidence of anterior talofibular ankle ligament rupture. The degree of swelling or ecchymosis is proportional to the likelihood of fracture.

The drawer sign is best elicited with two hands, with the patient sitting so the weight of the foot distracts the ankle joint to its normal degree. With one hand cupped over the heel and the other hand providing counter pressure over the front of the tibia at the level of the ankle, carefully assess the degree of movement. Repeat these steps for the other ankle, and compare results. In a person with lax joints, several millimeters of movement bilaterally is a negative ankle drawer sign finding. A positive ankle drawer sign finding is a difference of movements in a relaxed patient between the injured and uninjured side, with the injured side having more movement than the uninjured.

Women often have more tibial varus than men because the pelvis is wider in females. When this increased tibia varus is associated with increased calcaneal eversion range of motion, these women are at greater risk for ankle ligament trauma. Men with increased talar tilt are at greater risk of ankle sprain.

Indications for surgery are limited in patients with sprained ankles. One of the few absolute indications for surgery is a distal talofibular ligament third-degree sprain that causes widening of the ankle mortice. When this is found on radiograph, screwing the distal tibiofibular articulation together is absolutely indicated to restore the ankle mortice. The usual postoperative course entails avoiding weightbearing for 6 weeks followed by removal of the screw and then continuing external immobilization while allowing weightbearing for an additional 6 weeks. One of the reasons for this program is to avoid breakage of the syndesmotic screw and the attendant difficulties that may present.

An isolated medial complete ankle sprain with a palpable defect and demonstrable clinical instability, particularly if the deltoid ligament is caught in the medial ankle joint, is an indication for surgery to remove the ligament from the joint and repair the ligament.

Evans reported the outcome of 100 randomly selected patients with isolated lateral ligament sprains 2 years after injury. Patients were divided into 2 groups, each with 30 individuals with anterior ligament sprains only and 20 individuals with both anterior and middle ligament ruptures. Fifty patients were treated surgically, and 50 patients were treated with cast immobilization. This study demonstrated no functional or symptomatic advantage for those who were treated surgically. The nonsurgically treated group returned to work earlier and had less morbidity than the surgically treated group of patients (Evans, 1984).

However, Staples reported that young, active, athletic patients with tears of both anterior talofibular ligaments and calcaneofibular ligaments are best treated surgically. He reported a group of young athletic patients with only 58% satisfactory results after immobilization and later reported a group of similar patients who had surgical repair with 88.9% satisfactory results (Staples, 1972; Staples, 1975).

The average age of the young, athletic patients that Staples reported on was 19.7 years. The average hospital stay was 7.6 days in the group of patients who underwent surgery. Six of the 27 patients who underwent surgery had complications (22.2%). Two postoperative complications were reported, namely, marginal necrosis of the skin at the wound edge and hypesthesia of the 4th and 5th toes and adjacent forepart of the foot. In select young patients with high athletic demands who have both anterior talofibular and fibulocalcaneal complete ruptures, surgical repair may be the treatment of choice. In Staples’ discussion, the group who underwent surgery had more careful postoperative supervision than did the group who underwent cast treatment alone. Five of 8 (62.5%) of the patients with double lateral ligament complete rupture demonstrated by arthrograms who had refused surgical treatment were completely asymptomatic at one or more years after injury.

The consistent observation of most authors seems to be that the cause of continued symptoms after ankle sprain, regardless of the method of treatment, is incompletely understood. Equal supervision of the postinjury course may tend to lessen the difference in outcomes between the surgical and conservative treatment protocols. Newer methods of bracing, such as a controlled ankle motion (CAM) walker and the air cast type braces, protect well while allowing mobility and may provide better outcomes than rigid casting. Further research is needed to determine the best treatment for complete double ligament lateral ankle sprains.

Lab Studies:

• No laboratory studies are indicated for isolated ankle sprains.

Imaging Studies:

• Radiographs

• Plain radiographs may be clinically indicated to diagnose a fracture of the ankle or foot.

• Ankle stress radiographs contribute little to the management of acute ankle sprains because surgical treatment of the acute sprain is rarely indicated. Abnormal swelling or clinical ankle instability in an acute sprain may be documented with bilateral stress radiographs of the ankle.

• MRI

• MRI is not indicated unless unusual features, such as extensive swelling, ecchymosis, and pain, are present that may suggest an osteochondral lesion not observed on plain films.

• Even if MRI demonstrated bone bruising or actual articular cartilage damage, conservative ankle sprain treatment is indicated initially.

• Arthrogram

• Ankle arthrograms may be useful to determine capsular damage and number of ankle ligaments damaged. However, arthrogram is only indicated if surgery is indicated, and indications for surgery for double lateral ligament complete tears are still under debate. Staples found that arthrogram provided the most preoperative information.

• Ankle arthrograms are not indicated in every patient considered for surgical treatment. Marked clinical instability in a young individual with great physical demands being considered for surgery would mean that an ankle arthrogram is required.

Staging:

• Ankle sprains are classified into the following 3 grades:

• Grade 1 is a symptomatic stretch within the tensile limit but without failure.

• Grade 2 exceeds the limits of tensile strength, with failure of part of the ligament fibers.

• Grade 3 is complete failure of the ligament fibers.

• Ankle sprains are primarily staged or graded clinically. The degree of swelling and ecchymosis and the clinical stability of the ankle determine whether the ankle ligaments are stretched without significant tear (grade 1), partially torn (grade 2), or completely torn (grade 3). Arthrograms, stress radiographs, and MRI add little to the management of the ordinary ankle sprain. In order to have any significance, stress radiographs should be performed on both ankles.

Medical therapy: Most ankle sprains heal spontaneously with immediate ice applied locally, elevation for the first 24 hours after injury, the use of an ankle support as long as symptoms persist, and avoidance of activity that hurts. Many immobilization devices are comfortable and conform to the ankle with air cushion pads (eg, air cast). Immobilization that allows movement until healing has taken place (3-6 weeks) is the criterion standard for ankle sprain treatment because the collagen fibers heal the fastest and orientate along the lines of force where protected movement occurs. Early movement also helps in decreasing swelling and the danger of fibrosis that normally develops in chronic swelling.

After the immediate swelling has subsided for acute third-degree ankle sprains, cast immobilization is indicated for 3 weeks followed by a walking boot or other ankle immobilization device. The physiologic rational for immediate ice and elevation is to decrease the swelling and reduce the danger of long-term postswelling fibrosis.

Surgical therapy: The 2 indications for surgical treatment of acute ankle sprains that are generally agreed upon are (1) deltoid sprain with the deltoid ligament caught intraarticularly widening the medial ankle mortice and (2) inferior tibiofibular syndesmosis sprain causing real or potential widening of the ankle mortice. Acute grade 3 tears of the interior tibiofibular ligament can occur with a normal radiographic appearance on images in which the patient is not bearing weight, which is the standard of care in acute ankle sprains because of the discomfort associated with bearing weight. Thus, keep in mind that normal radiographic findings may be compatible with the need for surgery.

Pain and swelling localized over the inferior tibiofibular syndesmosis should alert the clinician to tears in the syndesmosis complex that may be best treated with surgical fixation. Controversy remains concerning the surgical treatment of complete anterior talofibular and fibulocalcaneal tears (double ligament tears) or the rare cases in which all 3 lateral ankle ligaments are torn. In a young patient with athletic requirements, surgical repair of severe lateral ankle sprains are sometimes indicated.

Treatment of distal tibiofibular syndesmosis sprains consists of screw placement across the syndesmosis that remains in place for 6 weeks and is removed before weightbearing is allowed to avoid the difficult problem of screw breakage.

Surgical repair of the lateral ligaments is still debated. The exposure must be carefully made to avoid the sural nerve posteriorly and the lateral branch of the superficial peroneal nerve anteriorly. Nonabsorbable flexible suture is preferred to suture the tendons and the capsule. The peroneal tendon sheaths are opened and the tendons retracted to repair the calcaneus fibular ligament. The peroneal tendon sheaths should be repaired along with the joint capsule. Careful skin handling and meticulous repair are indicated, as the skin is thin and fragile over the lateral ankle, even in young athletes.

Intraoperative details: Open reduction of a deltoid ligament caught in the medial ankle is performed through a curved incision below the medial malleolus. For greater exposure, some surgeons prefer a vertical incision. The incision that the physician believes provides the least skin problems and heals the best in that physician’s hands is the best incision for that physician to use. Release the caught ligament, and suture the ligament together or suture it to bone with a trocar needle using a nonabsorbable pliant suture. A standard postoperative course should be followed, including splinting in the same manner as for conservative treatment of ankle sprains.

Postoperative details: Acute sprains that do not heal and become painless should alert the clinician to possible complications, such as loose body, posttraumatic arthritis, and occult fracture. An MRI could be helpful in defining a mechanical cause of continued symptoms that could be corrected surgically.

Follow-up care: Follow-up care is very important because ankle sprains tend to recur and progress to ankle instability if neglected. The goals of follow-up care are 3-fold.

First, the range of motion must be completely restored. This is most important to help prevent recurrence of ankle sprain. The desired range of motion is 10-15° of dorsiflexion of the ankle with the knee extended and a full 90° of plantarflexion. Stretching exercises, particularly for the tendo-Achillis and for both muscles that attach to the tendo-Achillis, are needed.

Home exercises after appropriate physiotherapy instruction are important.

Muscle strengthening after immobilization for any length of time is the second goal. Muscle strength can be targeted specifically with a physical therapist or simply with self-directed walking exercises; ideally, the individual walks 2 miles a day for 5 days a week for life. Daily walking exercise affords many health benefits besides increased ankle strength and fewer recurrences of ankle sprains. Thera-Band exercises for all muscle groups around the ankle can be self-directed after instructions from a physical therapist or other office staff personnel. Exercising specific muscle groups lacks the synergistic effect that is obtained from activities such as walking or using a proprioceptive board as described below.

The third goal is to restore and facilitate or develop proprioception sense in the ankle joint. Proprioception is facilitated or developed with physiotherapy instruction and help if necessary. A half- to three-quarter–inch thick piece of plywood measuring as long and as wide as the foot can be made and used economically at home for 6 weeks of self-directed exercises by a compliant and motivated patient. This proprioceptive board also helps with the stretching and strengthening exercises.

Half of a 3- or 4-inch diameter plastic or wooden ball is fixed to the center of one surface of the board. This device affords 2 levels of range of motion. The patient steps on it with the half of a ball down on the floor to perform 10 sets of ankle motion in plantarflexion and dorsiflexion. Then the foot is placed on the wood cross-wise, and side-to-side motions are performed 10 times. These sets of exercises are performed once or twice a day with the attention directed to what the foot is doing to facilitate the cerebellar-foot neural connections.

When these exercises are performed easily (after approximately 3 weeks), the range of motion is increased and the device in the opposite fashion. The plantarflexion and dorsiflexion motions can be performed with the foot sideways on the proprioceptive board. The side-to-side movements can be performed with the foot on the board so it fits the foot. Care must be taken with these exercises to avoid causing another ankle sprain, which is what the proprioceptive exercises are designed to prevent.

Criteria for the patient to return to sports are important. When the athlete can run without a limp or hesitation or pain, the patient can be approved to return to sports. Figure-of-8 measurement around the ankle and midfoot and compared to the contralateral side can be used to accurately measure swelling. Lack or presence of ankle swelling has been reported to poorly correlate with function ability; hence, running without pain or limp is the preferred criteria for returning to sports, assuming that the patient has regained proprioceptive sensation, muscle strength around the ankle, and a full range of motion or has reached a plateau for several weeks with range of motion (particularly postoperative) and is pain free with a clinically stable ankle. Meeting all of these criteria is necessary to minimize the recurrence rate for repeat ankle sprains and to minimize chronic symptoms following a severe ankle sprain.

Protective strapping and use of an ankle support or high-topped footwear are strategies that may help reduce the ankle sprain recurrence rate. There is no substitute for a full range of motion, ankle strength, and proprioception function in decreasing the recurrence rate for ankle sprains.