Ankle sprains are one of the commonest injuries from sports and dancing. They are often underestimated. Most people have heard of the RICE protocol (rest – ice- compression – elevation) for ankle sprains, however this is only appropriate for Grade 1 tears.

Grade 2 and 3 tears require more focused treatment or they will not heal well, with the result that the ankle is at risk for further injury, permanent damage, and surgery.

Any ankle sprain where there is any degree of significant swelling, any bruising or difficulty walking after the injury requires proper evaluation by an appropriate expert. A thorough physical examination of the leg, ankle and foot is also often supplemented with x-rays (Ottawa Rules). This will catch Grade 2 + 3 sprains, as well as more serious injuries such as high ankle sprains, Achilles or other tendon tears, and fractures of the ankle and foot.

In the absence of any other significant injuries, Grade 2 sprains are best treated with 1 week of immobilisation in a non-removable backslab and u-slab. Full weightbearing is permitted as tolerated. For Grade 3 sprains, the length of immobilisation is 2 weeks. 

While immobilisation in a backslab is generally unpopular with people active with sports and life, it is also true that most people who eventually require surgery for their ankles after serious ankle sprains were either never placed into a backslab with u-slab at the start, or they removed the backslab themselves at home after a few days because they believed that they felt fine. Do not underestimate a significant ankle sprain!

After removal of the backslab, referral to physiotherapy is important, in order to strengthen tibialis anterior and peroneal muscles, and then restore balance and position sense with proprioception training. 

Around 95% of all ankles will return to normal with this protocol, with only 5% requiring consideration for surgical treatment.

Note that there is no role for routine MRI of the ankle in the initial stages following an uncomplicated low ankle sprain. In the surgical world, there is a truism “treat the patient, not the MRI”. MRI research on completely “normal” ankles without any history of injury and no symptoms, shows that abnormalities are found in 30% of normal ankles on MRI. After a proper physical examination has confirmed the ankle sprain, and x-ray has ruled out any other significant problem, performing an early MRI does not bring peace of mind. MRI will not predict the chances of successful healing in the individual patient. In fact, early MRI increases the uncertainty and therefore also increases the number of people undergoing needless surgery in the early stages after an ankle sprain.

Also note that after any significant sprain, the MRI will never again look normal, ever. This is because scar tissue does not look like normal ligament on MRI (because they are made of different type of collagen). Therefore, there is also no place for MRI in deciding when healing is complete. Healing is determined by expert clinical examination at the end of the rehabilitation programme, not by MRI.

The correct time to use MRI is when it is already clear that surgery is likely to be needed, for example in the small group of people who still do not have satisfactory ankle stability after the correct rehabilitation programme is complete. The MRI will then show which structures need to be surgically repaired, will assist in surgical planning and will inform length of post-operative healing time.

However, if unstable ankles that should have surgery, are not operated upon, risk of further injuries include peroneal tendon tears, osteochondral fractures of the talus dome, and eventual ankle arthritis.

Surgery is relatively straightforward, with satisfactory results. The surgery only takes about 1 hour, and the healing time requires 3 - 4 weeks of non-weight bearing on crutches in a cast, followed by 3 - 4 weeks of full-weight bearing in a foam walker boot with the same physiotherapy protocol. In most cases, people can return to previous normal levels of activity with sports compared to before the injury.