Lateral ankle ligament injuries are very common, especially in basketball and soccer players. If it is not diagnosed and treated in time, it can lead to many diseases and bring great inconvenience to daily life, study and work. Therefore, it is important to make a correct diagnosis and take effective treatment for patients with lateral ankle ligament injury in time.
What are the consequences of an improper treatment of lateral ankle ligament injury?
I. Overview
(A) Lateral ankle ligament injury
Lateral ankle ligament injuries are very common, with inversion sprains being the most common, accounting for 85%. Injuries to the lateral collateral ligament of the ankle account for 53% of basketball injuries, 21% of soccer injuries, and 23,000 ankle sprains per day in the United States.
(B) Comorbidities of lateral ankle ligament injuries
Injuries to the lateral collateral ligament of the ankle are often associated with.
1, peroneal tendonitis: when the ankle joint is turned inward, two tendons in the lateral part, namely the peroneal long and short muscles, develop tendonitis due to chronic strain.
2 . Anterolateral ankle impingement sign.
3. Ankle synovitis: the patient’s lateral collateral ligament scar heals, the collateral ligament is relatively lengthened, the ankle joint loses balance medially and laterally, and the patient will walk with talus inversion, which will lead to ankle synovitis for a long time.
Synovitis, free bodies, osteochondral lesions and bone redundancy secondary to lateral collateral ligament injury can be found arthroscopically in 93% of patients.
Therefore, if the lateral collateral ligament injury of the ankle is not treated in time, many diseases may develop in the long term.
(3) Chronic instability of the ankle joint
The incidence of chronic instability after acute lateral ankle ligament injury is 10-30%, and the patient shows repeated ankle sprains. When walking on uneven surfaces, patients report a feeling of instability. Therefore, it is imperative that lateral ankle ligament injuries are treated promptly. If not treated properly, the ankle ligament rupture will become scarred joint, resulting in ligament lengthening and laxity, causing imbalance of the medial and lateral ligaments of the ankle joint, which will result in excessive movement of the talus in daily activities and repeated sprains of the ankle joint, thus leading to traumatic arthritis of the ankle joint and degenerative changes of the medial side of the joint for a long time. There is no particularly good treatment for lateral ankle ligament injuries.
What are the ligaments of the lateral ankle joint? How strong are they? What is the role of each?
II. Functional anatomy of the lateral ankle joint
The anterior talofibular ligament, the heel fibular ligament and the posterior talofibular ligament are the most important ligaments of the lateral ankle joint.
(I) Anterior talofibular ligament
The anterior talofibular ligament is the weakest ligament among these three ligaments, its course is horizontal and its function is to prevent forward dislocation of the foot, i.e., to counteract forward displacement of the talus; its function is to limit inversion of the foot during plantarflexion.
(B) heel-fibular ligament
The heel-fibular ligament is moderately strong, with a posterior orientation, and when the foot is dorsiflexed, the ligament becomes vertical and downward, and relaxes when the foot is plantarflexed. The heel-fibular ligament restricts the inversion of the foot and has the greatest effect when the foot is dorsiflexed.
(iii) Posterior talofibular ligament
Among the lateral ankle ligaments, the posterior talofibular ligament is the strongest and its main role is to prevent excessive dorsiflexion of the ankle joint.
As can be seen, the anterior talofibular ligament and the heel fibular ligament are relatively weak and easily damaged. The role of both is to prevent inversion of the foot. When the foot is turned inward, these two ligaments are subjected to the greatest tension and are therefore the most prone to rupture.
What is the mechanism of lateral ankle ligament injury?
III. Mechanism of lateral ankle ligament injury
The lateral ligament is most likely to be injured in this position because all the ligaments of the lateral fibula are under the greatest tension when the talus is in internal retraction and internal rotation with plantarflexion. The heel-fibular ligament is the main tissue that prevents the talus from tilting, and the anterior talofibular ligament is the second line of defense. These two ligaments are the most commonly injured ligaments in clubfoot and lateral ankle sprains and must be repaired after injury.
What are the clinical manifestations of lateral ankle ligament injuries? How to diagnose lateral ankle ligament injury?
Clinical manifestations and diagnosis of lateral ankle ligament injury
(A) History of injury
There must be a clear history of injury; local swelling, ecchymosis, and pressure pain can be seen on physical examination, and there may be joint swelling. The reason why ligament injury can also cause joint swelling is that the lateral ankle ligament is woven together with the fibers of the joint capsule, so if the ligament is injured by torsion or violence, many patients will have joint capsule tears at the same time, and bleeding can enter the joint cavity through the fissure of the joint capsule, and then joint swelling and pressure pain can occur.
(ii) Physical examination
Examination of lateral ankle ligament injury: First, draw three pillar-like strips (the projection of the ligament on the body surface) on the lateral side of the foot, below the lateral ankle, indicating the anterior talofibular ligament, heel fibular ligament and posterior talofibular ligament respectively. The anterior talofibular ligament is the most prone to avulsion and rupture. This ligament can be identified by direct palpation.
Ankle sprains are actually more than just injuries to the lateral ligaments. If the violence is particularly high and the energy is particularly high, ankle inversion can also result in injury to the inferior tibiofibular joint ligament, which is common in clinical work. Treatment is very complicated when the inferior tibiofibular joint ligament is involved in addition to the lateral ankle ligament injury. Injuries to the inferior tibiofibular joint ligament must be diagnosed clinically, and if the diagnosis is missed and only the lateral collateral ligament is treated, the outcome will not be satisfactory.
The squeeze test can help to identify whether a patient with an external ankle sprain also has an injury to the inferior tibiofibular joint ligament by squeezing the calf muscle with both hands medially.
(iii) X-ray examination
The foot and ankle is composed of 26 bones, and the joint surfaces are facing different directions, and the shape of each bone is also very strange. Therefore, X-ray examination is important for the diagnosis of foot and ankle fracture, which can provide information on the type of fracture and help to decide the appropriate treatment. However, fracture lines may not be visible on plain X-rays. X-rays of the foot and ankle need to be taken in a special or stress position. X-rays are of very limited value for ligaments, as they are mainly for soft tissues to determine the presence or absence of swelling. There are many films of the foot and ankle, and they should be taken selectively according to the patient’s condition, in conjunction with the Ottawa Differential Diagnostic Criteria for Foot and Ankle Injuries, to reduce unnecessary radiation exposure and medical costs. However, this criterion is only applicable to skeletally mature adults with an injury within 10 days. For patients with foot and ankle injuries, weight-bearing standard anterior-posterior, lateral and ankle point x-rays must be taken. The main purpose of ankle point films is to help identify whether the inferior tibiofibular joint ligament is injured. This is because the diagnosis of inferior tibiofibular ligament injury is very critical to the overall treatment.
(iv) Special tests
In addition to X-ray examination, there are some special tests for ankle injury, such as stress test, including internal and external stress test and anterior and posterior stress test.
1. Inversion stress test: When taking the film, make sure to compare both sides so that the foot is in the extreme inversion position, take the film and measure the angle between the joint surface of the talus and the joint surface of the lower tibia. The normal angle should not exceed 5 degrees. If the angle between the affected joint surfaces is greater than 9 degrees or more on the normal side, the lateral collateral ligament of the affected ankle is damaged.
2. Anterior-posterior stress test: Check whether the foot can move forward and how far it can move. Make the knee joint flex 45 degrees (gastrocnemius relaxed), the examiner holds the distal calf with one hand and the heel bone with the other hand, push the foot forward and check the distance the talus moves forward (as shown in the figure on the right). Of course, the distance moved is very small (millimeter level) and cannot be seen with the naked eye, but can only be seen on an x-ray with or without force. This test is mainly to examine the anterior talofibular ligament.
Therefore, the inversion test is to check the stability of the anterior talofibular ligament and the heel-fibular ligament, and the talus is normally tilted no more than 5 degrees within the ankle cavity. If it is greater than 9 degrees compared to the contralateral side, it has diagnostic value. The anterior-posterior stress test, also known as the anterior drawer test, examines the stability of the anterior talofibular ligament: a shift of > 3 mm on the affected side compared to the contralateral side is clinically significant. This must be accurately measured on x-ray.
(v) MRI examination
MRI has a significant advantage over plain X-rays for ankle ligament injuries, as it can directly show the ankle ligament