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- Discussion:
    - larger than the anterior and middle facets and is convex in shape;
    - tarsal canal separates the posterior facet from the anterior and middle facets;

- Radiographs:
    - medial oblique axial view:
           - demonstrates middle & post facets of sub-talar joint;
    - lateral oblique axial view
           - demonstrates the posterior subtalar facet;
    - harris view:
           - for visualizing subtalar joint is enhanced by measuring angle of posterior facet on lateral view & then adjusting harris view to this inclination;
           - angulation of middle facet by > 20 degrees off horizontal is consistent with a coalition, even if the joint appears open

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Posterior subtalar joint arthrography. A useful tool in the diagnosis of hindfoot disorders.