Plantar Heel Pain Is Not Associated With Fatty Infiltration of the Abductor Digiti Minimi Muscle on Magnetic Resonance Imaging: A Cross‐Sectional Observational Study

BACKGROUND: Fatty infiltration, or fatty atrophy, of the abductor digiti minimi (ADM) muscle of the foot is proposed to be associated with entrapment of the first branch of the lateral plantar nerve (i.e., Baxter's neuropathy) as part of plantar heel pain (PHP). However, this association has not been rigorously investigated. The aim of this study was to determine if there is an association between PHP and fatty infiltration of ADM. METHODS: ). RESULTS: = 6.176, df = 3, p = 0.103) between PHP and fatty infiltration according to the four-point grading scale. CONCLUSIONS: After accounting for age, sex and BMI, there was no association between PHP and fatty infiltration of ADM. These findings suggest that adults with PHP do not have a greater predisposition for or amount of fatty infiltration of ADM compared to adults without PHP. Therefore, fatty infiltration of ADM is likely to be an incidental finding on MRI rather than a diagnostic sign of PHP, where Baxter's neuropathy may be present. Accordingly, clinicians should not focus on fatty infiltration of ADM on MRI to diagnose Baxter's neuropathy, or view it as a proxy marker, particularly when surgery for PHP is being considered.