Background: Proximal fifth metatarsal fractures are common. The authors previously performed a study examining the inter- and intraobserver reliability of the Lawrence and Botte Classification, which showed poor interobserver reliability of 16.67%. A novel approach was proposed for the classification of fifth metatarsal fractures using a mortise ankle radiographic view. Methods: The observers from the authors’ prior study reviewed non-weight bearing mortise views of 20 patients with isolated fifth metatarsal base fractures. These radiographs were identified from the 60 radiographs from the authors’ prior study. Five physicians evaluated the radiographs and classified the fractures as type 1, 2, or 3. Results were then analyzed for interobserver reliability. Results: Five observers reviewed 20 radiographs. Total interobserver reliability was 55.0% (11/20) with a Fleiss’ kappa of 0.565 (moderate agreement). The ankle mortise radiograph agreed with previous anteroposterior, oblique, and lateral radiographs at 56.0%, 57.0%, and 57.0%, respectively. Conclusion: There is poor inter- and intraobserver reliability in the current proximal fifth metatarsal classification system. The use of a mortise radiographic view for classification provides equivocal results in the reliability of classifying proximal fifth metatarsal fractures when compared to the typical 3- view of the foot. A future study should be aimed at a classification system with higher reliability.
Yeager, Kathryn; Benjamin Packard; Richard A. Miller; and Shravin Sridhar. "A Novel Method in the Classification of Proximal Fifth Metatarsal Fractures." Western Journal of Orthopaedics 10, 1 (2021). https://digitalrepository.unm.edu/wjo/vol10/iss1/8