Dr. Days .... - Muscat Private Hospital

Ankle sprain means traumatic lesion to the lateral ankle ligaments. It can be a simple stretching of the ligaments, the most important lesion being a complete rupture. The ankle sprain is the most frequent lesion seen in a pathology centre. 45% of all these injuries occur during sport. For example, a study about basketball players reveals that 76% of them sustained at least 1 ankle sprain. It is true that many of them heal spontaneously without any treatment. For this reason these trauma tend to be neglected as much by the patients as by the non specialist doctors. This is the most frequent cause of chronic post-sprains problems which could have been avoided in the case of an immediate and accurate diagnosis.

What happens to the ligaments and bones of an ankle in the case of a sprain?

A ligament is a band of solid fibrous tissue joining the bones between them. Concerning the ankle, we have a medial ligament joining the inferior tip of the tibia called medial malleolus and the medial aspect of the talus. This ligament is very solid and exceptionally impaired. The lateral ligament of the ankle presents 3 parts. Two of them join the tip of the fibula, called lateral malleolus to the lateral part of the talus and one joins the lateral malleolus and the lateral side of the calcaneus. For mechanical reasons, the different parts of the lateral ligament are permanently stressed during gait and exercise and are more prone to traumatic lesions. In an ankle sprain, the probability of a ligament rupture of any degree is maximal at the lateral side.

In the case of an ankle twist the lateral ligament can be stretched, partially or completely ruptured. Then the ankle becomes painful and swollen and it is difficult for the patient to walk on the impaired limb. At that stage, it is most important to assess the degree of rupture very carefully. This is done by stress X-rays of the ankle showing a loss of the normal anatomical relationship between the tibial articular surface and the dome of the talus. But the best and most useful exam is a careful clinical examination by an experimented doctor who will find clinically the abnormal displacements of the ankle. In the stress x-rays, we have often false negative exams due to the fact that the patient fights against the RX-technician because of fear and pain.

If one part of the ligament is torn the same treatment as above can be established, but an immobilisation for 4 to 6 weeks must be added. Most of the time the immobilisation consists in a compressive splint like Aircast®. Most of the time anti-inflammatory medication is prescribed for one week. Physiotherapy helps very much because many times, the sequence of activity of the ankle’s muscles is impaired by the sprain.

In case of complete rupture of all ligaments of the ankle, an immobilisation of the ankle by cast or immobilisation device is recommended for 4 to 6 weeks. During 2 weeks the patient will not be allowed to put his foot on the ground. Then he will be allowed to walk on the cast for 4 more weeks.

After removal of the cast physiotherapy with proprioceptive re-education of the ankle is recommended.

Surgical treatment

If fractures and small pieces of bone are seen on the X-Ray, an operation is then indicated. This will consist in removing or if possible fixing the piece of bone to its anatomical place and suture of the torn ligaments. After the operation the patient will have a cast for 2 weeks, a walking cast for 4 weeks after stitches removal and at the end physiotherapy.

What can happen in case of misdiagnosed or untreated ankle sprain?

1) As seen before, the occurrence of small pieces of bone (osteochondral fracture) is important in a high energy ankle sprain. If not diagnosed the pieces of bone irritate the ankle with chronic swelling and pain. Sometimes they can insert themselves between the bones and can cause a sudden block of the ankle with major pain. After some years, a arthritis of the ankle can occur because of the dysfunction of the ankle created by the osteochondral fracture. That’s the reason why they must be removed surgically.

2) In an untreated ankle with completely or partially torn ligaments, it is impossible for the ligaments to heal properly. The ligaments remain to long and weak and progressively a “Chronic instability of the ankle” develops itself. This condition is very invalidating: as soon as the patient puts his foot on the ground, he feels that his ankle is going away with major pain. The situation is aggravated in uneven ground like sand or stones. In small instabilities, a treatment of physiotherapy can be efficient but most of the time the patient must go to surgery. Fortunately the operations for chronic instability of the ankle are very good. Their goal is to make a reconstruction of the destroyed ligaments. The most habitual technique uses only the patient’s own soft tissue without any implant. After the operation the patient will have a cast for 2 weeks, a walking cast for 4 weeks after stitches removal and at the end physiotherapy.

Conclusion

Although it is considered by the public as a benign lesion, an ankle sprain if misdiagnosed or untreated can lead to major invalidity. The careful assessment of the degree of the ligament tear at the time of the accident is most important and must be clarified by a trained doctor. An X-ray is very important because of the frequent occurrence of chip fractures. In case of tear of the ligament, the treatment will be conservative most of the time depending of the degree of the lesion. Some rare cases necessitate surgery, particularly if there are small pieces of bone free in the joint. If the torn ligaments are untreated a chronic instability of the ankle can occur leading with time to arthritis with stiffening, pain and swelling of the joint. When an ankle sprain is diagnosed and treated properly, the prognosis is excellent leading to the normal function of the ankle with time.