MRI and ultrasonography in Morton’s neuroma: Diagnostic accuracy and correlation

Abstract

Background:The diagnosis of Morton's neuroma is based primarily on clinical findings. Ultrasonography (US) and magnetic resonance image (MRI) studies are considered complementary diagnostic techniques. The aim of this study was to establish the correlation and sensitivity of both techniques used to diagnose Morton's neuroma.Materials and Methods:Thirty seven patients (43 intermetatarsal spaces) with Morton's neuroma operated were retrospectively reviewed. In all cases MRI or ultrasound was performed to complement clinical diagnosis of Morton's neuroma. In all cases, a histopathological examination confirmed the diagnosis. Estimates of sensitivity were made and correlation (kappa statistics) was assessed for both techniques.Results:Twenty seven women and 10 men participated with a mean age of 60 years. Double lesions presented in six patients. The second intermetatarsal space was affected in 10 patients and the third in 33 patients. An MRI was performed in 41 cases and a US in 23 cases. In 21 patients, both an MRI and a US were performed. With regard to the 41 MRIs performed, 34 were positive for Morton's neuroma and 7 were negative. MRI sensitivity was 82.9% [95% confidence interval (CI): 0.679–0.929]. Thirteen out of 23 US performed were positive and 10 US were negative. US sensitivity was 56.5% (95% CI: 0.345–0.768). Relative to the 21 patients on whom both techniques were carried out, the agreement between both techniques was poor (kappa statistics 0.31).Conclusion:Although ancillary studies may be required to confirm the clinical diagnosis in some cases, they are probably not necessary for the diagnosis of Morton's neuroma. MRI had a higher sensitivity than US and should be considered the technique of choice in those cases. However, a negative result does not exclude the diagnosis (false negative 17%).

The accuracy of ultrasonography and magnetic resonance imaging for the diagnosis of Morton's neuroma: a systematic review

“…Besides the information regarding size and location, it provides more information about the nature of the lesion and surrounding changes, 12,13,26 and is able to distinguish the lesion from other soft-tissue masses with high signal intensity, such as bursae, schwannomas, and neoplasms. 2,27 Bencardino et al 19 reported that MRI had a sensitivity of 100% and a specificity of 68% in the investigation of Morton's neuroma, whereas Sharp et al 12 reported 86% and 100%, respectively.…”

“…16 Biasca et al 28 found that in contrast to the clinical findings, preoperative localization and diagnosis of Morton's neuroma was better achieved with MRI. 28 TorresClaramunt et al 13 came to the conclusion that MRI had a higher sensitivity than ultrasound and should be considered the technique of choice in some cases. The results of the present study support the former opinion, because ultrasound has a similar sensitivity, lower negative likelihood ratio, and higher specificity and positive likelihood ratio than MRI.…”

Diagnostic Value of Elastography in the Diagnosis of Intermetatarsal Neuroma

“…US sensitivity has been reported to be 56.5% to 100% in published studies (4,7,29,(32)(33)(34)(35). Likewise, the mean size of interdigital neuromas has been reported to vary from 4.9 to 7.4 mm (3,4,11,33,35,36).…”

Is it time to rethink the diagnosis of Morton’s Neuroma?

“…The fact that none of our patients required neurectomy leads us to seriously question the existence of this condition as initially described. Numerous authors have noted the inaccuracy between the various diagnostic methods available for Morton's Neuroma [10,11]. These inaccuracies can result in illadvised and unnecessary treatment and even surgical interventions.…”