16 Jan Tarsal Coalition
A tarsal coalition is described as an abnormal connection that develops between two tarsal bones in the foot. The abnormal connection itself can be bony, cartilaginous or fibrous, and may lead to decreased range of motion as well as pain
The most common cause of tarsal coalition improper formation of the tarsal bones during fetal development. It can also occur secondary to infection, arthritis or a previous injury.
Many people have a tarsal coalition with no overt symptoms. In some cases, however, the symptoms appear between the ages of 9 and 16. These symptoms include mild to severe pain when walking or standing, fatigued legs, muscle spasms in the leg, flatfoot, limping, and stiffness of the foot and ankle.
A tarsal coalition can be difficult to diagnose, especially during childhood. But as the bones mature, it becomes easier to detect in adulthood. s Careful history taking and a thorough examination of the foot and ankle are required for the diagnosis. Special tests such as reverse Coleman block test can be performed to test for subtalar rigidity. X-rays imaging may also be required to confirm the diagnosis and plan management. This includes getting anteroposterior, standing lateral foot, and 45-degree internal oblique views, as well as the Harris view of the heel. In some cases, a CT scan is ordered as part of the preoperative workup to rule out additional coalitions, as well as to determine the size, location, and extent of the coalition. Occasionally, an MRI may be ordered to visualize a fibrous or cartilaginous coalition.
Nonsurgical treatment of tarsal coalition is aimed at relieving the symptoms and to reduce the motion at the affected joint. For pain relief, oral nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may be effective. Physical therapy is also helpful. Steroid injections can be administered into the affected joint to reduce the inflammation and pain. Orthotic devices can be used to help in distributing weight away from the joint and limiting motion at the joint. Medial arch support can be provided with preserved hindfoot alignment
outcomes. The foot needs to be immobilized using a cast/cast boot to give the affected area a rest for up to 6 weeks. Up to 30% of symptomatic patients will become pain-free with a short period of immobilization.
In refractory or advanced cases, surgery is chosen as a last resort, in cases where there are persistent symptoms despite nonoperative management. The surgical approach is determined based on the patient’s age, condition, arthritic changes, and activity level. The typical approach includes coalition resection with interposition graft, with or without correction of associated foot deformity. This can be an open or arthroscopic coalition resection. In about 80-85% cases, there will be pain relief. But in patients who had to undergo coalition resection of >50% size of the joint surface area, uncorrected hindfoot valgus, associated degenerative changes or subtalar arthrodesis, there are increased chances of failure. Postoperatively, the patients have to wear a short-leg, non-weight bearing cast for 3-4 weeks.
Complications include recurrence of the coalition, residual pain or stiffness due to misalignment or associated arthritis, or due to unrecognized 2nd coalition.