Cortical Avusion & Tuberosity Frx of Navicular

- Discussion:
    - most common type of navicular frx;
    - caused by a twisting force (usually eversion) applied to the foot;
    - acute eversion of foot, resulting in increased tension on posterior tibial tendon or anterior fibers of deltoid ligament, places avulsion pull on navicular tuberosity, producing this fracture;
    - note that this fracture often occurs along w/ compression frx of cuboid; & is part of a larger midtarsal frx;
            - often avulsion of navicular tuberosity are considered to be an isolated injury, & attention is not given to entire mid tarsal joint complex;

- Exam:
    - local tenderness, combined w/ pain on passive eversion or active inversion of the foot;

- Radiographs:
    - frx is best viewed on AP and medial oblique x-rays of foot in equinus;
    - accessory bones of the foot:
            - two accessory osscicles, os supranaviculare & os supraatalare, can occur in this region;

- Treatment:
    - small avulsion fractures are treated w/ short leg cast for 4 to 6 weeks;
    - larger avulsion fractures can be treated w/ internal fixation;
    - in some cases, a painful exostosis will develop, and this can be excised after frx healing

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Wednesday, September 5, 2012 3:44 pm