The ankle joint is a hinge between the leg and the foot. The bones of the leg (tibia and fibula) form a sort of slot and the curved top bone of the foot (talus) fits between them. The talus is held to the tibia and fibula by strong bands of tissue called ligaments. Each ligament is made of many strands or fibres of a material called collagen, which is extremely strong.
The ligament on the inside of the ankle (medial or deltoid ligament) has two layers; the deepest one is most important. This ligament is mainly torn in association with severe fractures of the ankle bones.
The ligament on the outside of the ankle (lateral ligament) is made up of three bands: one at the front (anterior talo-fibular ligament), one in the middle (calcaneo-fibular ligament) and one at the back (posterior talo-fibular ligament). The front band is the usual ligament injured in sprains or tears of the ankle ligaments, and the middle band is sometimes affected.
The tibia and fibula have a small joint between themselves just above the ankle. This also has strong ligaments, one at the front and one at the back. (tibio-fibular ligaments). The ligament at the front is involved in 10-20% of ankle sprains; the ligament at the back, like the deltoid ligament, is mainly damaged in association with severe fractures of the ankle bones.
Most ankle ligament injuries are caused when the foot twists so that the sole is pointing inwards (inversion), usually when the foot is pointing downwards rather than flat on the ground. When this happens, the full force of the body's movement is placed on the anterior talo-fibular ligament. This may stretch, with tearing of some of its fibres (sprain) or it may tear completely. If there is a major injury of the anterior talo-fibular ligament, the forces transfer to the calcaneo-fibular ligament and the tibio-fibular ligaments, which may also be sprained or torn. Occasionally small pieces of bone may be torn off with the ligaments.
In a few cases, a twisting force on the ankle may cause other damage. The bones around the ankle may be broken, a piece of the joint surface inside the ankle may be chipped off, ligaments connecting other bones in the foot may be sprained or torn, or the tendons around the ankle may be damaged.
Most ankle sprains are fairly minor injuries which will get better with simple self-care treatment. For a south Indian it is easy to remember the word PRICE which forms the basic treatment of a sprained joint:
If there is no bony fracture and X rays are normal then protected weight bearing is useful. Also start to exercise and stretch the injured ankle as soon as possible after the swelling and acute inflammation decreases.
Normally a sprained ankle will recover within 6-8 weeks, although it may tend to swell for a few weeks longer.
If you have a severe ankle injury it is best to get professional advice immediately. Things that suggest a severe injury include:
Most ankle injuries get better completely and cause no long-term problems. Sometimes, however, there is some permanent damage to the ankle. The ligaments may fail to heal properly and become weak, or there may be damage to the joint cartilage itself or some other structure nearby. You would feel this as a tendency for your ankle to "give way", often with minor stresses. This might make you prone to repeated ankle sprains. This is referred to as "ankle instability" and is more commonly due to damage to the ligaments
Foot and Ankle Surgeon should examine you and he/she will try to see if there is anything, which makes you more liable to ankle instability than average. They will look for any sign that you have some other problem around your ankle, such as damage to the joint surface. They will stretch your ankle in various directions to see if the ligaments are abnormally weak.
An Xray will usually be taken to see if there is any damage to the bones of your ankle. Ligaments do not show on Xrays. A magnetic resonance imaging (MRI) scan is helpful in clinching the diagnosis in chronic cases.
As most people with ankle instability have proprioceptive nerves which are not working properly, the first treatment is a physiotherapy programme to re-train these nerves how to respond to movements of the ankle, by doing various exercises and activities. If your ankle or Achilles tendon are stiff, you will also be shown exercises to stretch these, and the strength of the muscles around the ankle will be increased by exercises. Many people will find their ankle much more stable and comfortable after physiotherapy. However, in some people problems continue. At this point the opinion of an orthopaedic foot and ankle surgeon would be helpful. If you have not already had the special tests mentioned above, these may be done now.
If no other treatment makes your ankle comfortable and tests show that the ligaments are weak, an operation will help. During the surgery, the damaged ligaments are tightened up and re-attached to the bone – often known as the Brostrum procedure. This surgery aims to achieve an anatomical repair of the ligaments. In sports personal an "internal bracing" may be used to further augment the repair for the harsh playing in future.
You would usually be in a plaster or brace for several weeks after an operation and would need further physiotherapy to help regain normal function.
The other problems which may occur after a ligament reconstruction operation include: pain in the ankle, either because of damage of the cartilage at the time of the original injury. If that is also involved , cartilage surgery also has to be done.
Your ankle may be just taking longer than usual to recover. However, there may be some other damage to the ankle if it is still causing trouble three months after injury. It would be worth consulting your Foot and Ankle Orthopaedic Surgeon.
You can't absolutely prevent another injury, but there are things you can do to reduce the risk. Obviously, take care when walking to avoid catching your foot on uneven bits of pavement (especially when you are in a hurry or have had a few drinks). High-heeled shoes put extra stress on your ankle and should be avoided. If your ankle or Achilles tendon are stiff this puts extra stress on your ankle ligaments when you walk or run, and exercises would probably improve this.
If you play sport, you should take extra care to warm up and down properly, with plenty of stretches to your ankle and Achilles tendon. Strapping your ankle or wearing a sports ankle support may reduce the risk of another injury but this has not been conclusively proven. If your injury was a bad one, it would be worth asking a physiotherapist about a re-training program for the proprioceptive nerves in your ankle.