Tarsal coalition in paediatric patients.

Tarsal coalition is due to failure of segmentation between two or more foot bones during embryological development at a site where the joint cleft fails to develop. Depending on the nature of the tissue connecting the bones, the abnormality is a syndesmosis, synchondrosis, or synostosis. Although the coalition exists at birth, synostosis usually develops only late during growth. Talo-calcaneal and calcaneo-navicular coalitions account for over 90% of all cases of tarsal coalition. The joint at the site of the coalition is stiff. Pain during physical activity is the main symptom, although recurrent ankle sprain is another possible presenting manifestation. During the physical examination, range-of-motion limitation at the hindfoot or midfoot should be sought, as well as varus or valgus malalignment of the hindfoot. Either pes planus or pes cavus may be seen. Calcaneo-navicular coalition may be visible on the standard radiograph, whereas talo-calcaneal coalition is best visualised by computed tomography or magnetic resonance imaging. As growth proceeds, the coalition becomes ossified and range-of-motion diminishes. Onset of the pain is often in the second decade of life or later. In patients with symptomatic tarsal coalition, the initial management should always consist in non-operative treatment for at least 6 months. A consensus exists that surgery should be offered when non-operative treatment fails. Open resection of the coalition is the treatment of choice, although endoscopic resection is also an option. Sound evidence exists that resection of the coalition can produce favourable outcomes even in the long-term. Fusion should be reserved for failure of resection, extensive coalitions, multiple coalitions, and patients with advanced osteoarthritis.