ANKLE SPRAINS Dr. J. Shawn Leatherman

ANATOMY & FUNCTION

Joints are formed where bones come together. The bones are held together by tissue called ligaments. Ligaments allow for controlled motion of the bones at the joint and limit excessive motion. Sprains occur when ligaments are stretched more than normal and result in a partial tear or complete tear of the ligament. This ligament damage results in the development of abnormal motion at the joint due to the loss of stability.

The ankle is a joint which is formed by the TIBIA and FIBULA (bones above the ankle in the foreleg) and the TALUS (below the ankle joint). The ankle joint allows for the upwards (dorsi-flexion) and downwards (plantar-flexion) motion. The end of the shin bone (tibia) forms the inner bony prominence of the ankle called the medial malleolus. The outer bony prominence is called the lateral malleolus and is formed by the small outer bone called the fibula.

Stability arises from two important factors: the unique structural arrangement of the bones forming the joint, and the surrounding ligaments. Joint instability may develop after damage occurs to one or more of the bones surrounding the joint, a fracture, but instability from surrounding ligament damage is more common.

KEY TERMS:

• Tibia, Fibula, Talus, Calcaneus
• Medial and Lateral Malleolus
• Inversion and Eversion
• Plantar Flexion (PF) and Dorsi-flexion (DF)
• Isotonic Exercise

SPRAIN
The term sprain merely indicates that a ligament has been damaged. Sprains are divided into several groups depending on the severity of damage to the involved ligament. The sprain occurs when the ankle is turned unexpectedly in any direction that is further than the ligaments are able to tolerate. Typically, the sprain occurs with running, jumping, sharp direction changes, or stepping on uneven ground. The risk factors for having an ankle sprain include, uneven ground, previous untreated ankle injuries, being overweight, or using poorly fitting or worn out shoes.

Grade I Sprain (First Degree)
A Grade I sprain is the most common and requires the least amount of treatment and recovery. The ligaments connecting the ankle bones are often over-stretched and damaged microscopically, but not actually torn. The ligament damage has occurred without any significant instability developing.

• Mild sprain, mild pain, little swelling, and joint stiffness may be apparent
• Stretch and/or minor tear of the ligament without laxity (loosening)
• Usually affects the anterior talofibular ligament
• Minimum or no loss of function
• Can return to activity within a few days of the injury (with a brace or taping)

Grade II Sprain (Second Degree)
A Grade II injury is more severe and indicates that the ligament has been more significantly damaged, but there is no significant instability. The ligaments are often partially torn.

• Moderate to severe pain, swelling, and joint stiffness are present
• Partial tear of the lateral ligament(s)
• Moderate loss of function with difficulty on toe raises and walking
• Takes up to 2-3 months before regaining close to full strength and stability in the joint
  

Grade III Sprain (Third Degree)
A Grade III sprain is the most severe. This indicates that the ligament has been significantly damaged, and that instability has resulted. A grade III injury means that the ligament has been torn.

• Severe pain may be present initially, followed by little or no pain due to total disruption of the nerve fibers
• Swelling may be profuse and joint becomes stiff some hours after the injury
• Complete rupture of the ligaments of the lateral complex (severe laxity)
• Usually requires some form of immobilization lasting several weeks
• Complete loss of function (functional disability) and necessity for crutches
• Usually managed conservatively with rehabilitation exercises, but a small percentage may require surgery
• Recovery can be as long as 4 months

On the medial (inside) of the ankle is the deltoid ligament complex which goes from the medial malleolus of the tibia to the talus, but is not frequently injured.

The lateral ligaments are the most commonly injured. The mechanism of injury is the forceful INVERSION of the foot in relation to the lower leg. On the lateral side, the ligaments are typically damaged in a direction that goes from the front to the back, with the most severe injury being in the front (anterior) and the least severe being in the back (posterior). Therefore, the most commonly damaged ligament is the anterior talo-fibular ligament and the least commonly damaged is the posterior talofibular ligament.

• ANTERIOR TALO-FIBULAR LIGAMENT (goes from the talus to the fibula)
• CALCANEO-FIBULAR LIGAMENT (goes from the calcaneus to the fibula)
• POSTERIOR TALO-FIBULAR LIGAMENT (goes from the talus to the fibula)

DIAGNOSIS (DX)
DX is determined by examination of the location of the bruising, swelling, and tenderness. It is also necessary to perform stress testing of the ligaments to determine whether the ligament has been torn. Stress testing of the ligaments is done by pushing on the ankle and attempting to determine if there is any abnormal motion at the joint which would indicate that a ligament has been torn. In addition, x-rays are often performed to check for the possibility of a chipped bone or fracture.

When performing a stress test of the ligaments, a posteriorly directed force is applied to the front of the tibia (shin bone). If the ankle ligaments are completely torn, the tibia will visibly shift backwards at the ankle joint. When the force is removed, the tibia will snap back into its proper position at the ankle joint. When this abnormal motion occurs, the anterior talo-fibular ligament (ATFL) has been torn.

Compare the normal ankle with the abnormal ankle. In the later x-ray, the torn ATFL has allowed the tibia to shift backwards. Notice how the joint surfaces of the tibia and the talus (red circle) are not lined up in the second x-ray.

TREATMENT (TX)

Depending on the severity of the sprain, treatment may range from simply wearing a supportive brace, to using a walking cast, or even having the ankle operated on. The type of treatment depends on several factors including severity of injury, presence of associated injuries, the routine stresses that are placed upon the ankle, and the general medical condition of the injured patient.

Many problems resulting from sprains are due to blood and edema (swelling) in and around the ankle. Minimizing swelling helps the ankle heal faster. Most sprains heal completely within a few weeks. With increasing injury severity, the rehabilitation process becomes more complex and extensive. Chronic or recurrent lateral ankle sprains usually receive some type of strengthening program and proprioception training due to poor balance on the injured leg.

Treatment-Phase I (Early Phase):
Goal: Decrease post-injury swelling, bleeding, and pain. Protect the healing ligament(s).

Avoid the first 24 hours:

• Hot showers, Hot packs
• Heat rubs (e.g. Ben Gay)
• Drinking alcohol
• Aspirin–it prolongs the clotting time of blood and may cause increased bleeding into the ankle (Tylenol or ibuprofen (Advil) may be taken to help with pain, but will not speed up the healing process)

The PRICE regimen is the most important aspect of the initial management of a sprain:

PROTECTION

• Ligaments must be maintained in a stable position so healing can occur
• Get off your feet if pain persists
• Use an ankle stirrup or brace if necessary
• Non-weight bear or partial weight bear with crutches to control other inhibitors of healing
• Early walking is essential, since weight bearing inhibits contractures (tightness) of tendons, which may lead to tendonitis
  

REST

• Allow injured ankle to rest for approximately 24 hours after the injury
• Caution should be taken against vigorous exercise
• Exercise for the uninjured leg may be performed
• Isometric exercises (to increase static strength and assist in decreasing atrophy) with toes pointing up (DF) and then down (PF), progressing to toes pointing in (Inv) and then out (Ev)–done in pain free motion (each exercise held for 6-8 count)

ICE

• Ice the ankle every 2 hours for 20 minutes to decrease pain, swelling, and spasticity for the first 48-72 hours
• Do not place ice on the ankle for over 20 minutes

COMPRESSION

• Done with ice
• Place air or cold water within enclosed bag to provide pressure to decrease swelling
• Ace wraps, which may be wet to facilitate the passage of cold, could be used - wrap distal to proximal
• To add more compression, a horseshoe-shaped felt pad may be inserted under the wrap over the area of maximum swelling

ELEVATION

• Elevate as much as possible with ice and compression
• Elevate foot higher than the waist to reduce swelling and pain
• Keep the leg elevated while sleeping
• Elevation allows gravity to work with lymphatic system rather than against it
• Elevation also decreases hydrostatic pressure to decrease fluid loss and also assists in venous and lymphatic return through gravity

Treatment-Phase II (Rehabilitation Phase):
Goal: To increase motion and strength, aid in circulation and help eliminate residual inflammatory agents.
This phase begins when swelling stops increasing and pain lessens, so that the ligament(s) have reached a point in the healing process at which they are not in danger given minimal activity. Pain is the guide as to how much activity is enough.

STRETCHING

• Do stretches before and after activity
• Vigorous heel cord/calf stretches initiated ASAP (hold stretches for 20 seconds each, performed every 2 hours) - moderate pull but no pain
• Begin with active Dorsi-flexion and Plantar-flexion activities
• Progress to Inversion and Eversion exercises when tenderness over the ligaments decrease
• All activities should be done slowly without pain at high repetitions (3 sets of 20)
• Toe curls–place a towel on the floor and curl your toes to pick up the towel
• Marble pickups–pick up marbles with your toes
• Perform alphabet exercise–rest heel on floor and write the alphabet in the air with your big toe, making the letters as large as you can
• Stationary bike

STRENGTH
Begin with isometric exercises with progression to isotonic exercises (with and without resistance) in a pain free motion .As the ligament heals further and ROM increases, strengthening exercises may begin in all planes of motion . Pain should be used as the basic guideline for deciding when to start Inversion and Eversion isotonic exercises.

Obtain a strip (about 2 feet long) of elastic belting material, surgical tubing (from a medical supply store), or a bike tire inner tube and work your ankle in four directions. Pull the tubing taut, making sure that the tube is placed at the base of your toes, and do the exercises only with your foot and ankle, not the whole leg

• Out and up: sit on floor or chair, loop tubing over foot and around table leg, with heel on floor, work ankle out and up
• In and up: as above, but loop tubing to provide tension against an inward motion, with heel on floor, work ankle in and up
• Straight up: as above, but with heel on floor, work ankle straight up
• Straight down: hold tube loop against bottom of foot, with heel on floor, work ankle down
• At the beginning of the rehabilitation process, use ankle weights (1-2 lbs) for light resistance in the four directions described above (2-4 sets of 20)
• Heel/toes raises–stand on a step with your heels slightly off the step and slowly rise up on your toes and equally slowly lower heel down; when this exercise becomes simple to perform, do the exercise using only the injured leg in a pain free motion
• Single knee flexion exercises–stand on injured leg and bend that knee and straighten it

PROPRIOCEPTION

• Defined as the knowledge of where one's body is in space
• Following ankle sprains, the injury can cause balance deficits (from loss of proprioception), and therefore increasing the risk of re-injury and poor healing
• The greater ligament disruption, the greater proprioception loss
• Early weight bearing on the ankle (e.g. standing/walking) decreases proprioception loss - begin by standing with eyes closed and progress to standing on injured leg with eyes closed
• Wobble-board ankle activities

Treatment-Phase III (Full Functional Level):
Goal: Return to prior level; return to activity

• Must have full ROM
• Must have 80-90% strength in injured ankle compared to the uninjured ankle
• Strengthen the uninjured leg
• Run in a pool, using a floating device; swimming
• Tape the ankle if necessary
• High-topped footwear to stabilize the ankle
• Cleats should be outset along periphery of the shoe to provide stability
• Gradual progression of functional activities that slowly increase stress on ligaments
• Full weight bearing when you can walk without a limp
• Lunges forward, on a 45° angle, and sideways with injured and uninjured leg
• Pain-free hopping on affected side (start with hopping with both legs and progress to hopping with only injured leg)–four-square hopping drills
• Step up and over, forward and sideways, on high step in pain free motion
• Stand on your toes of the injured ankle for 20 seconds, and hop on your toes 10 times
• Begin Stairmaster, treadmill, biking
• Running can be started as soon as you can walk in a fast pace without pain; initially, start jogging in a straight line, and progress to running from smooth, flat surface to uneven surfaces
• Cutting exercises: run in figure eights, cross-over walking
• Jump rope

RESIDUAL ANKLE INSTABILITY
Occasionally, when the ligaments heal, they are weaker or looser then prior to the injury. This results in an ankle that is more likely to be unstable and twist more easily. When this happens, PT often allows the adjacent muscles to strengthen and stabilize that joint. Sometimes, it is necessary to wear a brace when walking on uneven ground or during sports to support the ankle. Rarely, it is necessary to surgically reconstruct the ligaments. Prevention is the best way to protect the ankle from initial and further injury.

Prevention:

• Wear the correct shoes for the event. Proper footwear provides comfort and balance
• Wear hiking shoes or boots in rough terrain
• Different sports activities call for specific footwear to protect feet and ankles. Use the correct shoe for each sport. Don't wear any sports shoe beyond its useful life. Remember that wet conditions may necessitate a change in footwear.
• Do not walk barefoot on paved streets or sidewalks.
• Watch out for slippery floors at home and at work
• Be aware of uneven terrain, potholes, and high curbs.
• If you get up during the night, turn on a light. Wear a brace or have ankle taped when doing activities that have a high incidence of ankle injuries (such as basketball, volleyball, soccer, tennis, and other sports requiring a lot of stopping, starting, and twisting motions)