Review Question - QID 3016

The clinical presentation and image are consistent with a calcaneonavicular tarsal coalition. For symptomatic patients, a trial of nonoperative treatment is the first line of treatment. A firm orthosis to decrease inversion and eversion stress can be utilized or a short leg casting may be tried.

Tarsal coalition is the most common cause of peroneal spastic flatfoot (pes planus). It is a disorder of mesenchymal segmentation leading to fusion of tarsal bones and rigid flatfoot. Calcaneonavicular coalitions are the most common form, and usually present in children 10-12 yrs of age.

Vincent reviewed tarsal coalitions and painful flatfeet in adolescent children, determining an overall prevalence of 1%. He found calcaneonavicular coalitions to be the most common, followed by a middle facet talocalcaneal coalition. He advocated initial immobilization, followed by surgical treatment in recalcitrant cases.

Cowell et al reviewed the radiographic films recommended for coalition diagnosis. They suggested an oblique view for a calcaneonavicular coalition, an axial (Harris) view for middle and posterior facet coalitions and a lateral view to view irregularities of the anterior facet. In symptomatic calcaneonavicular coalitions without degenerative changes, bar resection and extensor digitorum brevis (EDB) interposition is advocated.

Swiontkowski et al retrospectively reviewed 40 patients with 57 operations for tarsal coalitions. In 10 patients with talocalcaneal coalitions, 4 underwent successful excisions, while 6 had successful fusions. Out of the calcaneonavicular coalitions, 39 had resections and 5 underwent fusion. Overall, 2 patients had poor results that were attributed to poor technique and failed calcaneonavicular resection secondary to advanced degenerative changes.

Illustration A is an oblique radiograph demonstrating a calcaneonavicular coalition.

Incorrect Answers:
Answer 1: Triple arthrodesis is indicated in advanced coalitions that fail resection.
Answer 2: Coalition excision is indicated in calcaneonavicular coalitions that fail conservative treatment. In talocalcaneal coalitions that involves < 50% of joint, do not have degenerative changes of the subtalar joint and have failed nonoperative treatment, excision may also be option.
Answer 3: Subtalar arthrodesis is indicated in talocalcaneal coalition that involves > 50% of joint and have failed nonoperative treatment.
Answer 4: Plantar fascia repair is not an indicated treatment tarsal coalitions.