Tarsal Coalition - A Rare Find
Tarsal coalition, a rare foot condition that can be difficult to spot, but super satisfying when you catch it. Tarsal coalitions are connections between two bones in the foot, which have developed from birth. Not a common diagnosis, as it has been reported to occur in less than 1% of the population. Here is a deeper look at these interesting cases and practical approach.
The things that make this condition difficult to spot is the presenting symptoms are vague and very similar to other minor sports injuries. Symptoms can include anything from chronic pain in the mid-foot, recurrent ankle sprains or nothing at all. In my experience, patients usually report long-standing pain in their foot that doesn't improve over a period of several months. The typical age of presentation for those young patients who actually have symptoms tends to be late school age to early adolescence. Children's bones start out as cartilage and become more solid as they age. Therefore, the first symptoms can vary depending upon when the bones in the foot transition from a more flexible cartilage to a more rigid bone. In my experience, many times the patient does not have a rigid flatfoot as is noted in the classic case.
If the diagnosis is suspected, tarsal coalition can typically be identified on plain x-ray, particularly in the oblique view (see below). Of note, if the patient's coalition is more fibrous tissue than bone, it may not always show up on a plain x-ray. When more detailed imaging is needed, typically CT scan is the gold standard.
Approach to Treatment
The treatment varies depending upon the specific situation. My approach for young athletes with tarsal coalition is a step-wise approcah. With mild pain, I will simply start with physical therapy to see if we can increase mobility of the midfoot and strengthen the supporting muscle of the foot and ankle. When an athlete has more significant pain I will try a boot or short leg cast for about 1 month to decrease the irritation and motion at the coalition, and follow with physical therapy. If the first two steps have failed or the patient has been in severe pain for a prolonged period, I then would consider surgical intervention. A commonly used successful approach is to transect the coalition and place a bit of the patient's fat tissue in between the bones to prevent the formation of a new connection.