Morton’s Neuroma or Its Mimics: Diagnostic Yield of MRI and Radiographic Markers in Patients Referred with a Clinical Suspicion

Objective To determine the prevalence of Morton’s neuroma (MN) among patients referred with a clinical suspicion of MN, to identify alternative diagnoses, and to assess whether angular measurements and the Vulcan sign may help differentiate MN from its mimics. Materials and Methods This retrospective study included 265 feet from 244 patients (mean age, 50.7 ± 13.0 years; 75% female) referred for MRI with a presumptive diagnosis of MN between January 2020 and June 2025. All patients underwent radiography and MRI. Morphometric parameters including hallux valgus angle, intermetatarsal angle (IMA), and interphalangeal angle (IPA) were measured according to the affected web space (2/3 or 3/4). The Vulcan sign was documented on radiographs. Statistical comparisons were performed using Mann–Whitney U, Chi-square, and Fisher’s exact tests. Results MN was diagnosed in 167 feet (63.0%), while 98 (37.0%) demonstrated alternative diagnoses. The most frequent mimics were bursitis (32.8%), hallux valgus (30.9%), adventitial bursitis (24.5%), hallux rigidus (12.5%), and stress reaction (8.3%). The 3/4 IPA was significantly greater in MN compared with non-MN feet (p < 0.001), while no significant differences were observed in the 2/3 IPA or IMA. Comparisons between groups of bursitis and non-bursitis revealed no significant differences in any angular parameters. The Vulcan sign was significantly associated with MN in both the 2nd (p = 0.006) and 3rd (p < 0.001) web spaces but showed no discriminatory value for bursitis. Conclusion In this first study conducted exclusively in patients referred with a clinical suspicion of MN, and one-third demonstrated alternative diagnoses. The 3/4 IPA provided diagnostic value, and the Vulcan sign emerged as a specific marker for MN but not for bursitis. These results underscore the importance of detailed imaging assessment in differentiating MN from its mimics in clinical practice.