Tarsal coalitions: review of the literature and case report of bilateral dual calcaneonavicular and talocalcaneal coalitions.

Inasmuch as midfoot coalitions do not occur frequently, a preadolescent or early adolescent patient who has persistent complaints of painful flat foot with peroneal or anterior tibial muscle spasm warrants special evaluation. The patient may complain of becoming easily tired or report the onset of pain with increased activity. Clinical examination may reveal local tenderness over the area of the coalition, but this is not a consistent finding. Restricted inversion of the foot with spasm of the peroneals, forefoot abduction or pronation should alert the examining physician that a tarsal coalition may be present. Appropriate roentgenograms examining all of the possibly involved joints should be obtained. These include 45 degrees oblique views of the foot, which usually give a satisfactory view of the calcaneonavicular joint. Coalitions may occur in any of the facets of the talocalcaneal joint and therefore all facets must be evaluated. The anatomic location of the facets can be variable and multiple-angle axial views may be required. We recommend a 45 degrees axial view to visualize the posterior and middle facets, since they are normally parallel in the axial view. If fibrous coalitions are present, the middle facet may be oblique. Tomography is necessary to visualize the anterior facet or to confirm a coalition either in the middle or in the posterior facets.