Mastering The Treatment Of Complex Ankle Sprains
My biggest complaint about typical ankle examinations is the lack of understanding and poor early treatment of high ankle sprains and syndesmosis injuries. To check this problem, the patient bends the knee and hangs the leg off the bed. The patient holds the knee tight and one performs an internal and external rotation of the ankle with the foot dorsiflexed to check the ankle and distal tibiofibular stability. If external motion causes pain, suspect a syndesmosis injury. Furthermore, one should also suspect a syndesmosis injury if pain is present with anterior distal ankle palpation.
What The Diagnostic Imaging Can Reveal
Following the physical examination, conduct radiographic examination of the ankle. If the patient has a severe lateral ankle sprain, obtain foot and ankle views to rule out a fifth metatarsal base fracture. Check the ankle views for fracture, cartilage damage, osteochondral lesion findings and syndesmosis injury. Increased medial clear space is a clear indicator of a syndesmosis injury.
However, more subtle cases can occur when there is a gapping of the tibiofibular overlap with more than 3 mm of overlap change. Comparing views of the anterior ankle to the contralateral ankle can be helpful in subtle syndesmosis injury cases. High fibular views can also be useful to check for a fibular neck fracture, which may cause common peroneal nerve irritation.
It is rare to order a magnetic resonance image (MRI) with an acute injury but in certain cases, MRI may be beneficial. In cases of potential tendon tear, osteochondral lesions with suspected loose body or subtle syndesmosis injury, it may be useful to obtain a MRI. This is especially true with syndesmosis injuries. In such cases, if one notes a sole anterior or posterior tibiofibular tear, it may be beneficial to stabilize the area acutely to avoid long-term complications, especially if mild anterior or posterior shift of the fibula is present. Again, syndesmosis injuries can cause severe long-term complications so err on the side of aggressive treatment to avoid problems.
Pertinent Treatment Tips
Treatment of an acute ankle sprain is mainly conservative in nature. In most cases, the treatment is an ankle brace of some sort. The type of ankle sprain varies but the main goal of the brace should be to stabilize the ankle in dorsiflexion and protect against excess medial and lateral motion. I prefer an over the counter ankle foot orthotic brace in order to support the ankle and the foot, and prevent overpronation. I also prefer this brace because it allows the ankle to be held in a dorsiflexed position and also gives some squeeze to the distal tibiofibular region for added stability.
When the patient has a very unstable ankle, such as a grade 3 sprain with complete ligament tears, I prefer a short period of either casting or boot use to allow the ligaments to heal prior to bracing. My patients usually use the boot for about two weeks until there is moderate healing of the ankle ligaments prior to bracing and therapy.
I also have found physical therapy on an acute care basis to be very helpful. By starting early soft tissue therapy, there is less swelling and improved circulation leading to improved tissue repair. Soft tissue laser therapy has been exceptionally helpful in soft tissue healing and tissue repair. Furthermore, early proprioception exercises are helpful in returning the ankle to stability and a feeling of balance.
In cases of loose bone or intra-articular cartilage damage that is loose in the joint, one should consider early arthroscopy to remove the intra-articular lesion and prevent arthritis. Early diagnosed osteochondral lesions without loose bodies usually undergo treatment with boot use. In order to allow for healing, patients are non-weightbearing for a period of about four weeks. One should subsequently obtain a repeat MRI to check the improvement in cartilage healing.
At our institute, we treat syndesmosis injuries aggressively with open fixation. One may perform this with one or two syndesmotic screws, or tightrope syndesmosis fixation. I prefer the tightrope technique, which allows early motion and does not need to be removed at a later date like screws.