ANKLE SPRAIN

ANKLE SPRAIN

A large percentage of musculoskeletal injuries observed in the outpatient setting involve the ankle.

Sprains constitute 85% of all ankle injuries.  

Of these, 85% are inversion sprains. Up to one sixth of participation time lost from sports results from ankle sprains.

Proper rehabilitation begins with accurate diagnosis, because up to 40% of patients with untreated or misdiagnosed ankle injuries develop chronic symptoms.

Most injuries respond to treatment. Pain reduction is essential, but improvement of any loss of motion, strength, and/or proprioception is equally important.

PATHOPHYSIOLOGY

The lateral ankle complex, which is composed of the anterior talofibular, calcaneofibular, and posterior talofibular ligaments, is the most commonly injured site.

Approximately 85% of such sprains are inversion sprains of the lateral ligaments, 5% are eversion sprains of the deltoid or medial ligament, and 10% are syndesmotic injuries.

The anterior talofibular ligament is the most likely component of the lateral ankle complex to be injured in a lateral ankle sprain.

Osteochondral or chondral injuries of the talar dome should be considered when diagnosing an ankle injury.

FREQUENCY

Sprains of the lateral ankle complex make up 38-45% of all injuries in sports. In one study, 50% of patients with ankle sprains had recurrence.

MORTALITY/MORBIDITY

Each day approximately 25,000 people suffer an ankle sprain. Up to 40% of these individuals have residual symptoms due to chronic instability.

Because instability is a potential problem following an ankle sprain, it is important that this injury be treated aggressively to prevent further disability.

AGE

Because older individuals tend to be less active than younger persons, and therefore often lack conditioning and proprioceptive conditioning, they are at risk for ankle sprain.

For similar reasons, weekend warriors and overweight individuals are at risk for ankle injuries.

CLINICAL

HISTORY

Determining the mechanism of injury is essential.

Sudden, intense pain and rapid onset of swelling and bruising suggest a ruptured ligament. Suspect neurovascular compromise if the patient complains of a cold foot or describes paresthesias.

Determine the presence of any complicating conditions, such as arthritis, connective tissue disease, diabetes, neuropathy, previous ankle sprain, or trauma.

PHYSICAL

Because most ankle sprains are tender during examination, observation can help the clinician to determine the severity of the injury.

• Observe for obvious deformity and note the location of ecchymosis and edema.

• The patient's ability to bear weight on the affected ankle and to ambulate also determines severity. In most cases, patients who are able to ambulate without severe pain are unlikely to have a fracture or instability.

• Ankle sprains commonly are classified into the following 3 grades:

  • Grade I - These sprains produce a mild degree of swelling, and stretch has occurred to the ligamentous structures. Weight bearing is possible.

  • Grade II sprains - These injuries are characterized by a moderate degree of swelling and an incomplete tearing of ligamentous structures. Mild instability may be present, but a definite endpoint is found on ligamentous testing. Pain may be noted with weight bearing.

  • Grade III - These sprains produce severe swelling and are defined by the complete rupture of at least 1 ligamentous structure. Evidence of instability may be noted.

• This grading system fails to characterize ankle injuries involving 2 or more ligamentous structures and excludes consideration of nonligamentous injuries.

• Drawer and talar tilt examination techniques are used to assess ankle instability; however, the use of these techniques in acute injuries is in question because of pain, edema, and muscle spasm. The fibular compression, or squeeze test, is used if a syndesmotic or fibular injury is suspected.

  • Perform the anterior drawer test with the ankle at 90° to the leg. Grasp the heel and pull forward while, with the other hand, placing posterior force on the tibia. If the test is positive, the so-called suction sign occurs. Dimpling is observed at the anterolateral aspect of the ankle, indicating compromise of the anterior talofibular ligament. A firm endpoint will be absent.

  • The talar tilt test also is performed with the ankle at 90° to the leg. Abduct and invert the heel. If a firm endpoint cannot be felt when compared with the opposite ankle, suspect damage to the calcaneal fibular ligament. Note that the degree of tilt ranges from 0-23°.

  • To perform the squeeze test, place the thumb on the tibia and the fingers on the fibula at the midpoint of the lower leg; then squeeze the tibia and fibula together. Consider pain along the length of the fibula, which indicates a positive test result.

CAUSES

Typically, plantarflexion and inversion of the foot occur, perhaps as a result of moving on uneven terrain or of landing on the foot of another athlete.

Overloading the peroneal muscles also may play a role. Invariably, ankle sprains involve trauma.

• Forced, external rotation of the ankle results in a syndesmotic, or high, ankle sprain. These injuries occur less frequently than do inversion injuries, but they are more disabling and require a prolonged recovery period.

• Recurrent ankle sprains or chronic, lateral instability are consequences of Grade III ankle sprains.

DIAGNOSIS

LABORATORY STUDIES

• Lab tests typically are not necessary for acute ankle sprains related to trauma or sports injury. Obtain appropriate studies if a rheumatologic condition is suggested.

IMAGING STUDIES

• Plain films of the ankle are not always necessary. Stress radiographic films may provide further assessment for ankle stability; however, patient cooperation may be limited, depending on the severity of the injury. Obtain radiographs in the following situations:

  • Bone tenderness is evidenced on palpation of the navicular, the base of the fifth metatarsal bones, or the posterior edge or tip of the medial or lateral malleolus.

  • The patient shows an inability to bear weight, which should alert the clinician to a possible fracture.

• Computed tomography (CT) scanning may be indicated if imaging of soft tissues is warranted or if bone imaging beyond radiography is indicated. In complex injuries, 3-dimensional CT scanning may be useful.

• Magnetic resonance imaging (MRI) may be useful when osteochondrosis or meniscoid injury is suspected in patients with a history of recurrent ankle sprains and chronic pain.

• A bone scan can detect subtle bone abnormalities (eg, stress fracture, osteochondral defects). A bone scan can also detect syndesmotic disruption.

OTHER TESTS

• Arthroscopy of the ankle may be used diagnostically and therapeutically in subacute or chronic ankle problems. Arthroscopy is indicated if osteophytes, meniscoid lesions, foreign bodies, or osteochondral defects are present.

TREATMENT

PHYSICAL THERAPY

Physicians frequently recommend physical therapy for patients who have suffered moderate to severe ankle sprains, especially persons who have chronic instability and recurring symptoms.

Following the acute injury, the physical therapist may provide therapeutic modalities (eg, cryotherapy, electric muscle stimulation)

to speed the reduction of pain and swelling.

As the patient progresses and is able to tolerate further therapy, the goals should be aimed at regaining the full range of motion (ROM), strength, and stability of the ankle joint.

The physical therapist also completes patient education throughout the rehabilitation process and establishes an appropriate home exercise program for each patient.

The goal of the program should be to enable the patient to return to his/her previous level of activity.

For less severe injuries, immediate, protected ambulation should be encouraged, and physical therapy should emphasize the return of ROM, strength, endurance, and proprioception.

MEDICAL ISSUES/COMPLICATIONS

Treatment during the acute phase of injury is meant to minimize swelling and allow the patient to begin walking.

The acute phase of treatment should last for 1-3 days after the injury.

A combination of protection, relative rest, ice, compression, elevation, and support is used. This approach can be remembered by using the mnemonic PRICES.

• Protection - Protective devices include air splints or plastic and Velcro braces. Most sprains can be treated without casting. Depending on the severity of the sprain, protective devices are used for 4-21 days. Criteria to discontinue use of the device include minimal swelling and pain at the site of injury. The ROM should be smooth, particularly with dorsiflexion and plantarflexion.

• Relative rest - Relative rest is advocated, because it promotes tissue healing. Advise the patient to avoid activities that cause increased pain or swelling. Advocate early, pain-free movements during this time. The patient may perform alphabet exercises or towel stretches, if tolerated, to maintain his/her ROM.

• Ice - Use ice to control swelling, pain, and muscle spasm. As a rule, do not apply ice or cold pack directly to the skin; wrap the pack in a towel before use. Recommend that the patient apply ice for 15-20 minutes, 3 times daily. Contrast baths can be used 24-48 hours after injury.

• Compression - Recommend the use of compression with an ACE wrap, an elastic ankle sleeve, or a lace-up ankle support. Advise the patient that further support of the ankle can be facilitated by wearing high-top, lace-up shoes. This can help to minimize edema.

• Elevation - Encourage elevation of the injured ankle to facilitate the reduction of swelling. Advise the patient to keep the ankle above the level of the heart.

• Support - This can include taping or the use of lace-up ankle supports with combination hook-eye (ie, Velcro) straps.

SURGICAL INTERVENTION

Surgery may be indicated when the fibulocalcaneal ligament is torn or a displaced or unstable fracture is identified. Most ankle sprains do not require surgical intervention.

MEDICATION

Analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) frequently are used to control pain and inflammation. Ultimately, the clinician has the prerogative to determine the most appropriate medication.

ANALGESICS

Pain control is essential to quality patient care. Analgesics ensure patient comfort, promote pulmonary toilet, and have sedating properties, which are beneficial for patients who have sustained trauma or injuries.

ACETAMINOPHEN (Tylenol, Panadol, Aspirin-Free Anacin)

Used for mild pain or if patient cannot tolerate NSAIDs.

Adult: 325-1000 mg PO/PR q4-6h; not to exceed 1 g/dose or 4 g/24 h

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Common reactions include rash, urticaria, and nausea; serious reactions include hepatotoxicity, nephrotoxicity, agranulocytosis, pancytopenia, thrombocytopenia, hemolytic anemia, pancreatitis, and angioedema; caution in impaired liver or renal function; hepatotoxicity possible in chronic alcoholics following various dose levels; severe or recurrent pain or high or continued fever may indicate a serious illness; acetaminophen (APAP) is contained in many OTC products and combined use with these products may result in cumulative APAP doses exceeding recommended maximum dose

NONSTEROIDAL ANTI-INFLAMMATORY DRUGS

If significant ecchymoses is observed at presentation of acute injury, consider not prescribing for 24-48 h, which may prevent further hemorrhage into the site of injury.

Several other NSAIDs are available. The ones listed here are considered first-line drugs on most formularies.

IBUPROFEN (Ibuprin, Motrin)

Used for analgesia and anti-inflammatory effect; take with food.

Adult: Mild to moderate pain: 400 mg PO q4-6h; not to exceed 2400 mg/d

Anti-inflammatory use: 600 mg PO qid or 800 mg PO tid x 7-14 d; not to exceed 2400 mg/d

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Caution in congestive heart failure (CHF), hypertension, and decreased renal and hepatic function; caution in anticoagulation abnormalities or during anticoagulant therapy

Common reactions include dyspepsia, nausea, abdominal pain, headache, dizziness, rash, elevated liver enzymes, urticaria, drowsiness, fluid retention, and tinnitus; serious reactions include anaphylaxis, GI bleed, acute renal failure, bronchospasm, thrombocytopenia, Stevens-Johnson syndrome, interstitial nephritis, hepatotoxicity, and agranulocytosis

NAPROXEN (Aleve, Naprelan, Naprosyn, Anaprox)

Used as an analgesic and anti-inflammatory medication; take with food.

Adult: Mild to moderate pain and anti-inflammatory uses: 250-500 mg PO bid; not to exceed 1500 mg/d x 3-5d