Chronic Ankle Instability
What's the problem?
When an ankle sprain occurs the ligaments that hold the ankle together are torn. Ligaments are like ropes that hold the bones together. After repeated injuries the ligaments sometimes heal in such a way that they no longer are able to provide the necessary stability to the ankle joint. That results in more frequent sprains as the ankle is prone to "turn" or "give way" more easily. Often patients with chronic ankle instability experience their ankle giving way with only minor twists, uneven surfaces or even small rocks in a parking lot.
Repeated injuries to the ankle can lead to damage to the surfaces of the bones and sometimes loose fragments of bone or cartilage within the ankle joint. These loose fragments can cause a locking or catching sensation which can sometimes be very intermittent (like a rock in your shoe) or sometimes produce constant pain (depending on where the loose piece is at any given time).
X-rays are important to look for old fractures, avulsions (when a very small piece of bone is pulled of with the ligament tear), loose pieces of bone or arthritic changes when there have been longstanding symptoms. CT scans or MRI scans are sometimes used when a more detailed evaluation is necessary, but these studies are not needed in all patients with ankle instability.
Treatment without surgery
Often after repeated sprains, the muscle strength and balance of the ankle is poor. A dedicated exercise program, often under the guidance of a physical therapist or athletic trainer can result in marked improvement in function, decreased pain and less frequent sprains. In addition to maximizing your "natural stability" by working on your strength and coordination, the use of an ankle brace can be very helpful in preventing recurrent injury. Use of a brace is NOT an excuse to avoid the necessary strengthening and balance rehabilitation. We can discuss with you the different brace designs that are available to you and what might be best for your individual situation.
Surgical repair of chronic ankle instability
If symptoms continue and limit your function in athletic activity or even in your daily activity despite the above measures, surgery can be very effective. The purpose of the surgery is to repair or reconstruct the ligaments that have been torn and no longer provide the necessary joint stability.
What is done at surgery?
We begin each surgery for ankle instability with ankle arthroscopy. This involves inserting a small camera into the ankle joint to evaluate the entire joint surface and to search for any cartilage damage or loose fragments of bone or cartilage that may be within the ankle joint itself. If there are arthritic changes in the ankle, these can be treated arthroscopically in many cases, including removal of painful bone spurs that occur in some very chronic cases. Arthroscopy allows us to see parts of the ankle that would not be visualized during the later portion of the procedure.
After the ankle arthroscopy, the ligaments must be repaired or reconstructed. If the ankle ligaments are found to be of good tissue quality and are pulled directly off the bone, the ligaments are repaired back to their natural locations. This is essentially a "delayed repair" and is referred to commonly as a "reconstruction." If the ligaments have healed in a lengthened stretched out position) the ligaments are imbricated or sewn over on themselves to shorten the ligaments to restore stability. This approach is referred to as a "modified Brostrum" procedure and has an excellent success rate of 90% or better in properly selected cases.
In very unusual situations, the ligaments themselves can be damaged to the degree that a secure repair or imbrication is not possible, then a tendon graft is used. The tendon graft is attached to the ankle bones in the precise location of the natural ligaments thereby rebuilding the ligaments. As the ankle heals, new tissue grows into and around the graft tissue resulting in a new "rope between the bones" and restoring the natural stability. The use of a tendon graft makes this a bigger operation and prolongs the recovery somewhat. If necessary I would recommend the tendon graft be a hamstring tendon graft that is harvested through a one inch long incision just below your knee. It is unusual in my experience to need to use a tendon graft. In most all cases there is adequate natural ligament tissue to complete the procedure well. Nonetheless, it is important that you understand that this is a possibility since we would want and need your permission to harvest the graft if it is needed.
Students should expect to miss up to about one week. Many students or office workers can go back about 3 days post-operatively. You will come back to the office about 10-14 days after surgery in most cases. At that point you will be switched from your post op splint to a walking boot. You will be allowed then to start putting weight on your ankle and over the next two weeks you will wean out of your crutches. We have a detailed rehabilitation plan that you may refer to for details. After about 6 weeks you will no longer wear the boot and you will have a lightweight ankle brace for normal walking around activities. Light jogging begins around three months after surgery and sports progression after that. Please see our protocol for details.