Case report: First description of a calcaneal fracture in a patient with cuboid navicular coalition

Cuboid navicular coalition (CN) is a rare type of osseous, cartilaginous, or fibrous congenital bridge arising from failure of differentiation of more than two tarsal bones. We report the first reported case of a 36-year-old male presenting with a calcaneus fracture associated with an osseous CN coalition with no prior coalition symptoms. CT and MRI demonstrated unusual fracture patterns extending into the middle facet with a middle facet and talonavicular subluxation. Initial emergency talonavicular reduction and delayed calcaneal open reduction and internal fixation (ORIF) was undertaken. The coalition was not excised as there were no prior coalition symptoms. This is the first reported case presentation of a rare CN osseous coalition presenting with a calcaneal fracture. Variations in presentation of calcaneal fractures may allude to the presence of a coalition requiring careful consideration of both pathologies when considering treatment.