Aim: To investigate the relationship between magnetic resonance imaging (MRI) findings and clinical features in patients with os naviculare.
Materials and methods: All patients with a foot or ankle MRI study showing an os naviculare were identified from a specialist orthopaedic hospital between 2014 and 2017. A total of 110 patients with 133 os naviculare were included. The MRI features were recorded, as well as the presence or absence of medial foot pain and/or tenderness over the navicular tuberosity. Fisher's exact test was used for categorical data and unpaired t-tests for continuous data. Specificity and sensitivity were calculated for MRI features.
Results: There were 80 female and 30 male patients with a mean age of 46±1.7 years at time of MRI (range 11-90.6 years). There was a significant correlation between os naviculare oedema (p=0.008) and navicular tuberosity oedema (p=0.001) with a history of medial foot pain. There were significant associations between mean age (p=0.003), type of os naviculare (p=0.004), os naviculare oedema (p<0.001), navicular tuberosity oedema (p=0.001), and soft tissue oedema (p=0.01) with examination findings of tenderness over the navicular tubercle. Oedema of the os naviculare, navicular tuberosity, or soft tissues were found to have a high specificity but low sensitivity for medial foot pain and tenderness.
Conclusion: When present, certain MRI findings indicate that an os naviculare is likely to be a cause of patient symptoms, but when absent they do not exclude the possibility of it causing symptoms.
Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.