Diagnostic Accuracy of Subjective Features and Physical Examination Tests for Morton Neuroma: A Systematic Review

Background: Morton neuroma (MN) is a common pathology with many reported subjective features and physical examination tests. The objective of this systematic review was to examine the diagnostic accuracy of subjective features and physical examination tests for MN.

Methods: CINAHL, CENTRAL, EMBASE, MEDLINE, PubMed, Opengrey, PEDro, PsycINFO, Scopus and Trials register were searched in January 2021. Two reviewers independently screened studies for inclusion using the following criteria: (1) prospective or retrospective cohort studies, (2) participants aged ≥18 years with suspected MN, (3) primary data allowing construction of 2 × 2 diagnostic table or reported sensitivity and specificity figures, (4) diagnosis of MN using magnetic resonance imaging, ultrasonography, surgery, positive response to steroid and/or anesthetic injection, and (5) in English or translatable. Quality of included studies was assessed using the Quality Assessment for Diagnostic Accuracy Studies version-2 (QUADAS-2) tool.

Results: The search yielded 1170 results, of which 9 were included in this systematic review. Narrative synthesis revealed that subjective clicking reported by a patient was highly specific (0.96) and had a high positive likelihood ratio (13.14). The modified webspace tenderness test (thumb index finger squeeze test) was highly sensitive (0.96) with a low negative likelihood ratio (0.04). The commonly reported feeling of "walking on a pebble" and "burning pain" had sensitivities of 43% to 53% and 54% to 57% and associated specificities of 52% and 48%, respectively.Only 1 study had low risk of bias. The review was limited by the number of studies that included few or no patients without MN, and the impact this had on the ability to calculate diagnostic accuracy.

Conclusion: There is strong evidence that clicking reported by a patient rules in MN and that the modified webspace tenderness test rules out MN when negative.