Acute lateral ankle ligament injuries are often also referred to as ankle sprains. It is one of the most common injuries in orthopedic outpatient and emergency departments. According to statistics, ankle injuries account for 15% of all sports injuries, and 85% of these are lateral ligament injuries.
When the ankle joint is in plantar flexion and subjected to inversion stress, the anterior talofibular ligament is strained and the increase in inversion stress can cause the ligament to tear or avulsion fracture of its attachment point. Excessive inversion then acts on the heel-fibular ligament, causing it to tear. This injury is likely to occur when a basketball player jumps and falls with his foot on another person’s foot, for example. Continued stress can also cause injury to the posterior talofibular ligament, but this is rare.
With a rupture of the anterior talofibular ligament alone, there is only anterior instability of the talus. With a rupture of the talofibular ligament alone, there is little effect on ankle stability, but there is a significant increase in subtalar joint instability. If the rupture of the anterior talofibular ligament is combined with the rupture of the heel-fibular ligament, the talus tilts under the stress of internal rotation; if all three bundles of ligaments rupture, significant ankle instability will occur.
(I) Classification
1. The standard classification of American Medical Association (AMA). Classify the ligament injury according to the degree of ligament injury. Is now widely used in the clinical classification method.
I degree: ligament twist injury. This means that the ligament is stretched, but not significantly torn. The ankle joint is stable, mildly swollen, and function is largely unaffected.
Grade II: Partial tear of the ligament. There may be mild to moderate instability and ankle function may be affected.
Degree III: Complete rupture of the ligament. There is obvious swelling, ecchymosis and instability.
2. Anatomical classification. According to the ligament of the injury.
Degree I: Anterior talofibular ligament injury.
II degree: anterior talofibular ligament and heel-fibular ligament injury.
Degree III: Anterior talofibular, heel-fibular and posterior talofibular ligament injuries.
3. Classification according to the stability of the ankle joint after injury.
Type I: Stable joint.
Type II: Unstable joint.
Type IIA: Negative ankle stress test, but with symptoms of ankle instability. For example, pain, swelling, ankle tend to hit soft and sprain repeatedly. This type is also known as functional instability.
Type IIB: Negative ankle stress test. The anterior drawer test has an anterior displacement of the talus >25px and the talus tilt test >15°. This type is also known as mechanical instability.
Type IIC: Inferior talofibular joint instability.
4. Trevino classification. This classification takes into account both the ligament, the degree of injury and the combined injury.
Type I: Ligamentous tear.
Type II: partial tear of the ligament.
Type IIIa: complete rupture of the anterior talofibular ligament.
Type IIIb: complete rupture of the anterior talofibular ligament and the heel-fibular ligament.
Type IIIc1: Type IIIb plus peroneal tendon tear.
Type IIIc2: Type IIIb plus dislocation or subluxation of the peroneal tendon.
Type IVa: Type IIIb plus avulsion fracture of the external ankle.
Type IVb: Type IIIb plus osteochondral fracture of the talus.
Type IVc: Type IIIb plus lateral talar eminence fracture.
(II) Clinical manifestations and diagnosis
In acute injury, there is a history of inversion sprain of the ankle joint, and some patients can hear or feel the sound of tissue tearing at the time of injury. Some patients can continue to walk with weight after the injury. Twenty-four to forty-eight hours after the injury, there may be bruising and ecchymosis under the skin of the lateral ankle joint due to the absorption and decomposition of the hematoma. The patient’s anterolateral ankle joint may be swollen on examination. Early in the injury, when the swelling is not severe, careful search for pressure points can help determine the exact site of ligament injury. Anterior talofibular ligament injuries often have pressure points at the fibular attachment point, while heel-fibular ligament ruptures often have pressure points at the heel attachment point. When the ligament is completely ruptured, the ligament rupture gap can sometimes be palpated. However, if it has been several hours since the injury and the swelling is heavy, the pressure points are not clear. Passive inversion of the forefoot and inversion of the ankle can cause increased local pain. After complete rupture of this ligament, the talus may become unstable in the anterior-posterior direction.
According to the patient’s performance after the injury, the lateral ligament injury is divided into three degrees: mild, moderate and severe.
Mild: Ankle function is mildly affected. There is no claudication and no or mild swelling. There are limited pressure points that can cause pain when the mechanism of trauma is repeated.
Moderate: Ankle function is moderately compromised. Walking limp, inability to actively dorsiflex the ankle, localized swelling and pressure pain.
Severe: extensive swelling and pressure pain. Patients need crutches
Whether the injury is acute or chronic instability, an examination of stability is important. The anterior drawer test and talar tilt test are often required in clinical practice to help determine whether the ankle is stable.
The anterior drawer test can be performed with the patient in the prone or sitting position. The patient’s knee is flexed to relax the calf muscles, and the examiner holds the patient’s heel with one hand and applies force forward, while the other hand holds the lower part of the distal tibia and applies force backward, pushing and squeezing with both hands and comparing both sides. A misalignment of the ankle joint can be felt on the unstable side. The talus tilt test can be done with the patient in a sitting position, with the ankle joint flexed 10°-20°. The examiner fixes the distal calf with one hand and holds the heel bone with the other hand to make it strongly inward, while feeling with the hand whether there is any separation of the lateral tibial talar joint.
X-ray examination: take routine frontal and lateral ankle joint and ankle cavity x-ray. If the ankle joint is unstable due to severe ligament injury or old injury, stress position X-ray should be done. Take lateral ankle radiographs under the drawer test to measure the relative displacement of the distal tibia and talus, and take orthogonal ankle radiographs under the passive strong inversion of the heel to measure the tilt angle of the talus. There is no consistent standard for normal and abnormal values of the two measurements due to individual differences, different ligament laxity, different stresses applied to the foot during the radiograph, and the effect of whether anesthesia is used. For example, Clanton believes that the anterior talofibular ligament is likely to rupture if it is greater than 5 mm, and the heel and anterior talofibular ligaments are likely to rupture if the talus tilt is greater than 15°. Patel believes that the anterior talofibular ligament is likely to rupture if the foot is displaced 6 mm anteriorly in neutral position and 8 mm anteriorly in plantarflexion; the heel and anterior talofibular ligaments are likely to rupture if the talus tilt is greater than 15° or 10° greater than the contralateral side. rupture is likely.
CT: Not very discriminating of soft tissues. In the case of lateral ligament injuries, CT can help to exclude osteochondral fractures of the talar bone, tarsal sinus fractures, tarsal bone bridges, and osteoid osteomas of the talus.
MRI: has a high resolution of soft tissues and can better differentiate between partial and total ligament tears. MRI is a useful test when the extent of ligament damage is needed to determine whether to operate, or when the patient needs further testing for poor results of non-operative treatment. However, it is less significant for the evaluation of joint instability.
Arthroscopy: In acute lateral ligament injuries, arthroscopy is generally not used as a means of examination. In chronic instability, arthroscopy can be used to examine and treat certain diseases of the ankle joint, such as talar osteochondral fractures, free bodies, and anterolateral soft tissue impingement syndrome of the ankle joint.
After an inversion injury of the ankle joint, not only the lateral ligaments of the ankle joint can be ruptured, but also other lateral structures can be injured or accompanied by ligament injuries. For example, ankle fracture, fifth metatarsal base fracture, talar osteochondral fracture, lateral talar eminence fracture, anterior calcaneal tuberosity fracture, inferior tibiofibular joint injury, inferior talocrural joint interosseous ligament injury, peroneal tendon and peroneal tendon support band injury, superficial peroneal nerve injury, and medial ankle ligament injury. Attention should be paid to the differentiation.
(C) Treatment
The choice of treatment modality after acute injury is still controversial. Most physicians believe that non-surgical treatment of Grade I and II injuries can provide satisfactory results. For degree III injuries, some doctors believe that early surgical repair can make the joint mechanically stable and thus achieve good clinical results; while other doctors believe that non-operative treatment can also make most patients get satisfactory results, even if a small number of patients become chronically unstable later, surgical repair can also achieve better results. For patients with severe 3rd degree injuries after repeated sprains, large avulsion fractures of the outer ankle, combined with more severe medial ankle injuries or osteochondral fractures of the talus, there are indications for stage I surgery.
1. Non-operative treatment consists of early RICE treatment and later functional rehabilitation. The whole rehabilitation process can be generally divided into 4 phases (Table). Generally functional rehabilitation takes 4-6 weeks. It depends on the severity of the injury, the length of fixation time, and the patient’s response to the rehabilitation training. The rehabilitation process is also long, requiring ankle protection for 3-6 months.
Table Rehabilitation plan for lateral ligament injuries
Phase 1 (acute phase)
Duration
1st degree injury: 1-3 days
2nd degree injury: 2-4 days
3rd degree injury: 3-7 days
Rehabilitation goals
Reduce swelling
Reduce pain
Prevent re-injury
Maintain proper weight-bearing status
Rehabilitation measures
1.RICE therapy
(1)Rest: Avoiding activities can reduce pain.
Cold compress (ice): cold compress with ice or ice water can make local vasoconstriction, reduce bleeding and swelling, also can reduce pain. It can be used for 20 minutes every hour, 3-4 times a day for 3 days. A cold compress can also be used (Figure 10-3-3).
(2) Compression fixation (compression); use various elastic bandages, adhesive tape, soft splints, braces, etc. for a short time to reduce swelling and pain and make the patient feel more comfortable. In case of severe sprain, apply plaster fixation (Figure 10-3-4, 5, 6).
(3) Elevation of the foot (elevation): promote lymphatic reflux and reduce limb edema.
2.According to the patient’s pain condition, non-steroidal anti-inflammatory painkillers can be given.
3. If the pain is not severe, the patient can walk with weight. The patient should be encouraged to walk with weight early. This can reduce proprioceptive damage and reduce muscle atrophy. Active muscle activity is also conducive to the reduction of swelling. If the pain is severe, crutches are required for walking.
If the pain decreases, the patient can enter phase 2 rehabilitation.
Phase 2 (subacute phase)
Duration
1st degree injury: 2-4 days
2nd degree injury: 3-5 days
3rd degree injury: 4-8 days
Rehabilitation goals
1.Reduce swelling
2. Reduce pain
3. Move within the pain-free range
4. Start muscle pulling exercises
5. Start non-weight bearing proprioceptive training
6. Appropriate protection
Rehabilitation measures
1. Reduce pain and swelling
Physiotherapy, gentle massage, elastic bandage fixation
2. Weight-bearing
If the pain and swelling are reduced, you can gradually start to walk with weight.
3. Mobility exercises
Active dorsiflexion and plantar flexion of the ankle joint, internal and external rotation exercises (Figure 10-3-7)
4.Muscle strength exercises
Isometric contraction of the peroneal muscle against assistance (Figure 10-3-8)
Toe pushing towel on the ground (Figure 10-3-9)
Toe clenching objects (Figure 10-3-10)
5.Proprioception training
Seated balance board exercises (Figure 10-3-11)
6. Joint pulling exercises
Passive dorsiflexion and plantarflexion activities in a painless state. You can start with one plane, such as dorsiflexion and plantarflexion. Later, gradually transition to multiple planes (except for internal and external rotation) (Figure 10-3-12)
Achilles tendon pulling (Figure 10-3-13)
Phase 3 (rehabilitation period)
Duration
1st degree injury: 1 week
2nd degree injury: 2 weeks
3rd degree injury: 3 weeks
Rehabilitation goals
Increase mobility
Increase muscle strength
Increase proprioceptive training
Increase daily activities
Full weight bearing
Rehabilitation measures
1. Muscle strength exercises
Heel lift exercises
Toe lifts
Alternating steps with both feet
Half squat
2.Anti-assist muscle strength exercises
Back extension, plantar flexion, internal and external rotation
3.Proprioception training
Standing balance board exercises or balance meter exercises (Figure 10-3-14)
Stretch soft bed exercises (Figure 10-3-15)
4. Brace protection to avoid re-injury
Phase 4 (functional recovery period)
Time
1 degree of injury: 1-2 weeks
2nd degree injury: 2-3 weeks
3rd degree injury: 3-6 weeks
Rehabilitation goals
Return to normal activities.
If there is mild joint instability, protect it and continue the exercises.
Rehabilitation measures
1. Continue joint mobility and muscle strength exercises.
2. Practice jogging under reduced weight (Figure 10-3-16).
3. Jogging under normal conditions.
4. Participate in various activities.
5. Participate in various competitions.
6. Use brace for protection for 3-6 months.