Review Question - QID 1042

Coalition resection and interposition of extensor digitorum brevis is an appropriate surgical option for most cases of calcaneonavicular coalition. Alternatively, fat interposition may be performed as some authors have demonstrated superior results with this method. Contraindications to resection of calcaneonavicular coalitions are advanced degenerative changes in adjacent joints or multiple coalitions, whereby an arthrodesis procedure is indicated. Obtaining a foot CT in a patient with a calcaneonavicular coalition can be helpful to identify a co-existing subtalar coalition not seen on the radiographs.
In contrast, for talocalcaneal coalitions, if involvement is less than 50%, then the coaltion should be resected; if greater than 50% involvement is present then subtalar arthrodesis is preferred. Advanced cases and cases that fail attempts at resection often require triple arthrodesis. Options 1, 3, and 4 are surgical options for talocalcaneal coalitions.

Swiontkowski et al reviewed 40 patients who had undergone 57 operations for tarsal coalition. Thirty patients had 39 calcaneonavicular resections and five primary triple arthrodeses. In the entire series only two patients had a poor end result due to either technically poor surgery or failed calcaneonavicular resection because of advanced degeneration.

The Level 4 articles by Comfort et al and Wilde et al reviewed patients with talocalcaneal coalitions. They found that there was better results if the talocalcanealcoalition resections were less than 33% or 50% of the total joint space, respectively.

Illustration A shows a drawing of a calcaneonavicular coalition.