Medial subtalar dislocation with navicular and posterior talar process fracture: the first report in the literature.

To cite: Eisenstein N, Hillier D, Ahmad S. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2012007763 DESCRIPTION Subtalar dislocations are rare types of injury and account for approximately 1% of all dislocations. There is simultaneous disruption of both the talocalcaneal and talonavicular joints, whereas the tibiotalar and calcaneocuboid joints remain undisturbed. Medial subtalar dislocations are the most common (up to 85%), with lateral types making up the majority of the rest. 2 Total anterior or posterior dislocations are extremely rare. These injuries may be associated with fractures of the bones of the foot and ankle. Reviewing the literature reveals no previous reports of posterior talar process and navicular fracture, in the presence of a total medial subtalar dislocation (as in this case). Fotiadis et al have reported on a medial subtalar dislocation with nondisplaced fractures of the talar body and navicular (figure 1). Papers describing total talar dislocation have shown that open reduction is required in most cases. This should be undertaken urgently as it reduces deformity and subsequent nerve, blood vessel or skin damage. Talectomy may be required as an interval procedure due to the development of avascular necrosis or osteomyelitis (eg, after open total dislocation). Ankle fusion is also described as a second procedure in cases of complicated total talar dislocation with or without accompanying fracture. Xarchas et al describe a closed method of reduction under general anaesthetic whereby the knee is flexed and the talus is pushed posteromedially. In this case, closed reduction under general anaesthetic failed. Open reduction was successful and revealed that the talus had ‘button-holed’ through the dorsal facia preventing closed reduction.