Take a look at your ankle bones. Are they straight across from each other? Is one in front of the other? Research shows that the position of these bones might have something to do with ankle injuries. Ankle sprains are a common sports injury. Identifying risk factors could help prevent ankle injuries. Could bone position be an identifying risk factor? This study compared the ankle bone position of two groups. One group of 61 patients had just sprained their ankles. The other group of 101 adults without ankle injury was the control group.
The researchers used CT scans to look at the position of the bones around the ankle. They found a range of positions for the control group from -8 to +16 degrees. If the bones are exactly across from each other, the angle is zero. If the outside bone (lateral malleolus) is in front of the inside bone (medial malleolus), the angle is negative. If the lateral malleolus is in back of the medial malleolus, the angle is positive. This measurement is called the malleolar index.
The group with ankle sprains had a wider index range, from -6 to +39 degrees. After analyzing the results, the authors report a higher number of injuries in patients with a positive malleolar index. In this group the lateral malleolus is behind the medial malleolus. The lateral malleolus is the bottom part of the bone along the outside of the lower leg, called the fibula.
How does knowing this help us? It shows us that some people may be more likely to injure their ankle than others. The authors point out this difference in anatomy doesn’t lead to injury until the body is in action. Many factors can cause ankle sprains. A posterior fibula is only one and may not make a difference by itself.
These scientists say the next step is to study the specific effect of this anatomic difference on ankle sprains. They will do this during athletic events. It may be that players with a posterior fibula should use an ankle brace or splint during sports to prevent injury. Perhaps special exercises will could also help.