Ankle Sprain

Background

Of the many functions of the ankle joint, one allows the body to adapt to uneven terrain during ambulation. Failure to compensate for uneven footing may result in an ankle injury.

Eighty-five percent of ankle injuries are sprains, and 85% of those are lateral inversion sprains (Garrick, 1982; Balduini, 1982). Most ankle sprains occur on the lateral aspect of the ankle. Although athletes usually recover quickly from ankle sprains, failure to rehabilitate appropriately imposes an increased risk for future injury.

Frequency

United States

The most common ankle injury is a lateral sprain caused by inversion of the foot, with more than 25,000 occurring each day in the United States (Pfeffer, 2001). They are also the most commonly seen sports injury, comprising 14-21% of sports injuries (Liu, 1999; Renstrom, 1994). Athletes participating in basketball, volleyball, soccer, and football are at especially high risk for ankle sprains, comprising 25-45% of injuries in these sports (Renstrom, 1994).

International

In the United Kingdom's general population, the prevalence of ankle sprains is reportedly 52.7 cases per 10,000 patients (Bridgman, 2003).

Functional Anatomy

The bony and soft tissue anatomy of the ankle place the lateral side of the ankle at higher risk than the medial side. The distal end of the fibula (ie, the lateral malleolus) extends further inferiorly than the distal end of the tibia (ie, the medial malleolus). This discrepancy in length gives the medial ankle superior stability by improving bony resistance to eversion.

The ligaments of the medial ankle, collectively known as the deltoid ligament complex, form a broad strong ligamentous stability to prevent eversion. On the lateral side, there is only minimal bony stability. Ligamentous stability comes from 3 relatively small ligaments, the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL), and the posterior talofibular ligament (PTFL). The deltoid ligament is a complex of very strong thick ligaments, which provides medial ankle stability. The syndesmotic ligament complex consists of the anterior tibiofibular ligament, the posterior tibiofibular ligament, and the distal interosseus membrane between the tibia and the fibula. A sprain of the syndesmotic ligament complex is sometimes called a "high ankle sprain" and often presents with anterior ankle pain.

In plantar flexion, the talus of the ankle is more susceptible to inversion forces compared to dorsiflexion when the talus is more stable with bony stabilization in the mortise. In plantar flexion, the ATFL is under tension and is susceptible to injury.

Although, many classification systems for grading lateral ankle sprains exist, perhaps the most common system is based on the clinical examination. In this system, Grade I ankle sprains are painful, but they have no increased laxity when compared to the uninjured side. This correlates with mild stretching of the ATFL. Grade II ankle sprains are painful with increased laxity on testing. This correlates with complete tear of the ATFL and partial tear of the CFL. Grade III ankle sprains usually are painful with an unstable ankle joint on examination. This correlates with complete ruptures of both the ATFL and CFL.

Sport Specific Biomechanics

Jumping, cutting, and pivoting place the ankle at risk for inversion injuries. Close body contact between athletes also places the athlete's ankle at risk for inversion injury (eg, stepping on the opponent's foot).

Treatment

Acute Phase

Rehabilitation Program

Physical Therapy

Rest, ice, compression, and elevation (ie, RICE) are the mainstays of the acute treatment of lateral ankle sprains (see Other Treatment section below). The goal of acute treatment is to control pain and to maintain or regain range of motion (ROM). Athletes are encouraged to take their ankle out of the brace and move it through a pain-free ROM. Aggressive pain-free ROM is recommended. Having the athlete spell the letters of the alphabet with his/her foot and ankle several times per day is one simple activity to recommend even in an acute care setting.

Medical Issues/Complications

Pain control is the initial treatment goal.

• The use of nonsteroidal anti-inflammatory drugs (NSAIDs) is somewhat controversial (Stanley, 1998). Some physicians argue that the anti-inflammatory effects of NSAIDs are helpful in decreasing swelling, which ultimately increases the speed of recovery. Others believe that acutely used NSAIDs may increase swelling by increasing potential bleeding through platelet inhibition (Stanley, 1998).

• If NSAIDs are not used, acetaminophen or other pain medicines may be required for pain control in some athletes with moderate to severe ankle sprains.

Surgical Intervention

Surgical intervention may be considered for the treatment of third-degree ankle sprains in high-level athletes and for chronic ankle instability. In most cases normal biomechanical function is not completely restored; but for most patients with chronic ankle instability, satisfactory results can be obtained with various surgical procedures (Kaikkonen, 1997; Tohyama, 1997; Rosenbaum, 1997).

Other Treatment

Rest, ice, compression and elevation are the mainstays of treatment; rest is especially critical. Athletes must modify activities that aggravate the condition; this modification may be as simple as decreasing the amount, frequency, or intensity of activity. Often, athletes are more compliant with a decreased level of activity, if they are allowed to increase other non-aggravating activities (Quillen, 1996).

• An ice pack is the first-line anti-inflammatory treatment; used appropriately, icing has been shown to significantly decrease healing time (Rubin, 1997). The pack can be made by placing crushed ice in a plastic bag that is wrapped in a towel; a good alternative is using a bag of prepackaged frozen corn kernels wrapped in a towel. Such an ice pack allows it to mold to the foot, thereby increasing the contact area. Ice packs (which should be used after completing exercise, stretching, and strengthening) are usually placed for 15-20 minutes.

• Placing a compression dressing over the ankle and elevating the ankle as soon as possible after the injury (for 24 h) are important in minimizing the swelling. Some useful commercial devices combine compression and ice treatments.

• Ankle braces

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• • Immobilization can both help and hinder healing. Acutely protecting the weakened, painful area is appropriate, but prolonged immobilization leads to muscle atrophy and loss of motion. Limited stress creates a stronger scar formation, as the collagen fibers line up parallel to the stress instead of at random. For these reasons, limited immobilization with a stirrup or lace-up ankle brace is usually used (see Media File 5) while casting is avoided.

• • Occasionally, the use of posterior splinting and crutches with non–weight-bearing ambulation is useful for more severe ankle sprains (ie, when foot motion and weight bearing is extremely painful). Usually, the use of a posterior splint is limited to a few days and weight bearing as tolerated is encouraged.

• • Ankle braces have been shown to be effective at preventing some types of ankle sprains (Anderson, 1995; Sitler, 1994; Surve, 1994; Rovere, 1988; Garrick, 1973). The use of high top shoes has been proposed to prevent ankle injuries, but study results have been mixed (Ottaviani, 1995; Barrett, 1993; Rovere, 1988; Garrick, 1973).

• Ankle taping

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• • Ankle taping can increase ankle stability by at least 2 mechanisms: limitation of motion and proprioception (Lephart, 1998). For a single treatment, ankle taping is less expensive than either a brace or an athletic shoe. Initially, the effectiveness of ankle taping is similar to bracing (Quinn, 2001; Arnold, 2004). However, studies have demonstrated a significant loss of effectiveness after 24 minutes of activity (Lohrer, 1999). Taping has also been found to become virtually ineffective after periods as short as 40 minutes (Manfroy, 1997).

• • The effectiveness of ankle taping is highly dependent on the expertise of the individual who performs the taping. Although the primary effect of taping is improved proprioceptive function, taping may also cause variable effects on motor performance. Taping has the potential to either enhance or hinder the function of the peroneal muscles depending on the location and technique with which the ankle was taped. Thus, having an experienced certified athletic trainer (ATC) or physical therapist do the taping usually produces optimal results. In general, athletes without easy access to an athletic trainer or physical therapist may find an ankle brace to be easier to use and more effective.

Recovery Phase

Rehabilitation Program

Physical Therapy

The treatment plan during the recovery phase is aimed at regaining full ROM, strength, and proprioceptive abilities. Strengthening is started with isometric exercises and advanced to the use of elastic bands or surgical tubing (see Media File 4). Strengthening is performed in the following 4 cardinal ankle motions: dorsiflexion, plantar flexion, eversion, and inversion. Strengthening of the peroneals, which act as dynamic stabilizers of the ankle, is critical.

• Proprioception rehabilitation begins with single leg stance exercises. The proprioception rehabilitation begins in a single plane and progresses to multiplanar exercises.

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• • The athlete stands on the injured side with the foot and arch in a neutral position and holds the foot of the uninjured side off the ground. This exercise should be completed near a wall for safety.

• • Initially, the athlete looks at the feet and attempts to hold the position. When the athlete can comfortably and easily hold the position for 3 minutes, he/she changes the focus of the eyes to a location in front of the body. When the athlete can comfortably and easily hold the position with the eyes looking forward for 3 minutes, the position is then held with the eyes closed. A modified Romberg test may be useful in evaluating proprioceptive rehabilitation progression.

• Other useful exercises include the use of a balance or tilt board (see Media File 3); these can be made by attaching a dowel or half of a croquet ball to the bottom of a piece of plywood. The athlete stands on the board and attempts to control balance while touching the board to the floor in a controlled manner to complete various patterns (eg, 4 points of the compass). Finally, the athlete advances to functional drills, jogging, sprinting, cutting, and then progresses to figure-of-eight and carioca drills (Osborne, 2003).

Surgical Intervention

Surgical intervention may be considered for the treatment of third-degree ankle sprains and for chronic ankle instability. In most cases, normal biomechanical function is not completely restored; but for most patients with chronic ankle instability, satisfactory results can be obtained with various surgical procedures (Kaikkonen, 1997; Tohyama, 1997; Rosenbaum, 1997). Symptoms of chronic instability may include chronic pain and instability despite a course of adequate physical therapy.

Maintenance Phase

Rehabilitation Program

Physical Therapy

A maintenance program of ankle strengthening, stretching, and proprioception exercises helps decrease the risk of future ankle sprains, particularly in individuals with a history of multiple ankle sprains or of chronic instability (Lephart, 1997; Sitler, 1994; Osborne, 2003; Stasinopoulos, 2004; Verhagen, 2004).

Medication

The use of nonsteroidal anti-inflammatory drugs in acute musculoskeletal injuries is somewhat controversial (Stanley, 1998). NSAIDs may or may not be beneficial to the physiologic processes of soft tissue healing. They have been found to be useful in controlling pain and allowing more rapid progression in physical therapy. Disadvantages of NSAIDs include the risk of gastrointestinal bleeding, gastric pain, and renal damage (McCarthy, 1998).

Drug Category: Nonsteroidal anti-inflammatory drugs

These agents are used to control acute inflammation and pain. They may also be used for pain control as an adjunct to physical therapy.

Drug Name	Ibuprofen (Ibuprin, Advil, Motrin)
Description	Member of the propionic acid group of NSAIDs. Available in low dose form as an over-the-counter medication. Highly protein bound, metabolized in liver and eliminated primarily in urine. May reversibly inhibit platelet function.
Adult Dose	600-800 mg PO tid/qid
Pediatric Dose	Recommended maximum daily dose: 40 mg/kg PO divided tid/qid
Contraindications	Documented hypersensitivity; peptic ulcer disease, recent GI bleeding or perforation, renal insufficiency, or high risk of bleeding
Interactions	Coadministration with aspirin increases risk of inducing serious NSAID-related adverse effects; probenecid may increase concentrations and, possibly, toxicity of NSAIDs; may decrease effect of hydralazine, captopril, and beta-blockers; may decrease diuretic effects of furosemide and thiazides; monitor PT closely (instruct patients to watch for signs of bleeding); may increase risk of methotrexate toxicity; phenytoin levels may be increased when administered concurrently
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Category D in third trimester of pregnancy; caution in congestive heart failure, hypertension, and decreased renal and hepatic function; caution in anticoagulation abnormalities or during anticoagulant therapy

Drug Name	Naproxen (Aleve, Naprelan, Naprosyn, Anaprox)
Description	Member of the propionic acid group of NSAIDs. Available in low dose form as an over-the-counter medication. Highly protein bound, metabolized in liver and eliminated primarily in urine. May reversibly inhibit platelet function.
Adult Dose	Dose range: 250-550 mg PO bid/tid; maximum 1100 mg/d when used for pain control and acute musculoskeletal injury; maximum daily dose is 1650 mg for all conditions
Pediatric Dose	10 mg/kg PO divided bid recommended
Contraindications	Documented hypersensitivity; peptic ulcer disease; recent GI bleeding or perforation; renal insufficiency
Interactions	Coadministration with aspirin increases risk of inducing serious NSAID-related adverse effects; probenecid may increase concentrations and, possibly, toxicity of NSAIDs; may decrease effect of hydralazine, captopril, and beta-blockers; may decrease diuretic effects of furosemide and thiazides; monitor PT closely (instruct patients to watch for signs of bleeding); may increase risk of methotrexate toxicity; phenytoin levels may be increased when administered concurrently
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Category D in third trimester of pregnancy; acute renal insufficiency, interstitial nephritis, hyperkalemia, hyponatremia, and renal papillary necrosis may occur; patients with preexisting renal disease or compromised renal perfusion risk acute renal failure; leukopenia occurs rarely, is transient, and usually returns to normal during therapy; persistent leukopenia, granulocytopenia, or thrombocytopenia warrants further evaluation and may require discontinuation of drug