The ‘peek-a-boo’ heel sign in the evaluation of hindfoot varus

Abstract

Basic to the diagnosis of foot disorders is a clinical appreciation of the shape and attitude of the hindfoot. We have found it helpful in evaluating patients for hindfoot shape to pay particular attention to the frontal clinical view to note if the heel can be seen medially, or if it is obscured from view by the foot. If the heel can be visualized medially when viewing the standing patient from the front, we describe it as a ‘peek-a-boo’ heel and use it as a clinical clue to the presence of hindfoot varus. In the normal limb, the heel cannot be seen from the front. In the standing patient, the normally valgus hindfoot places the heel ‘behind’ the foot. If the heel can be seen from the front in the standing patient, it may indicate hindfoot varus (Fig. 1). The ‘peek-a-boo’ heel can be seen with a plantarflexed first ray, a fixed hindfoot varus deformity, or in combination with external rotation of the limb with an equinocavovarus deformity.’ Possible etiologies of hindfoot varus include neuromuscular disorders such as CharcotMarie-Tooth disease, established leg compartmental syndromes, and idiopathic cavovarus deformity. Most clinicians view the patient from the back to determine heel position. It is from this position that hindfoot varus and valgus are defined. For example,