The anterior process of the calcaneus articulates with the cuboidal bone and the most lateral part of the navicular bone, it is part of the bottom of the sinus tarsi at the entrance of the calcaneal canal. The woman, in this case, made a fall from the stairs during her work as a district nurse. The bifurcated ligament is a strong band, divided in a Y-shape manner into a calcaneocuboid and a calcaneonavicular part. The proximal attachments of both ligaments originate from the superoanterior calcaneal process, and they course distally to attach on the navicular and cuboid bones, respectively. Her foot plantarflexed and her hindfoot inverted and the forefoot adducted in relation to the hindfoot in a downward direction, and the calcaneocuboidal ligament pulled off a portion of the bone (avulsion fracture). The patient reported pain and swelling in front of and outside the ankle; there was almost immediately a hematoma visible. These fractures are often misdiagnosed as ankle sprains because the presentation is so similar.
On examination, there was tenderness and swelling over the injured area left anterolateral ankle The injured area was similar to that of an ankle sprain, although the hematoma was located more plantar and distally than in a standard ankle sprain left foot (Clinical photo 1). There was no numbness indicating that the sural nerve or the superficial peroneal nerve was involved. The first evaluation was the quality of the anterosuperior and inferior talofibular ligament (US image) and the calcaneofibular ligament (US image). These ligaments were intact. The dynamic assessment of the talocrural joint was negative. The hematoma directed us to the calcaneocuboidal joint. A fracture of the anterior process was immediately visible with ultrasound by the cleft visible, and the widening of the jintspace of the calcaneocuboidal joint (US image calcaneal process). However, this injury can often be quite subtle and can easily be missed on X-ray. In the left-to-right comparison (US-left-right-image) the fracture was evident, because of the fragment visible and the absent upper fascicle of the calcaneocuboid ligament could indicate a rupture in combination with an avulsion. The fragment did not indicate a nutcracker fracture.
Calcaneal anterior process fracture, the fracture fragment is not interfering with the function of the calcaneal cuboid joint. The patient is treated non-surgically with immobilization in a walker for six weeks until the soft tissue injury, and fracture have healed. In some incidences, the fracture will not completely heal, which is only problematic if it interferes with the joint function.
Robert is a specialist in foot and ankle sonography. He studied Podiatry and in 2004, Robert founded Podiatry Care Netherlands. Since 2007 he specialized in rheumatism and ultrasonography.
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