Morton’s neuroma: the clinical picture revisited

D. Mahadevan, M. Venkatesan, R. Bhatt, M. Bhatia

Introduction: Various tests to clnically detect Morton´s neuroma (MN) have been described but none are pathognomonic and the most reliable technique has yet to be established.

Methods: A prospective study was undertaken on 54 feet with symptomatic Morton’s neuroma (MN) to identify the most common reported symptoms and clinical signs. Patients in a foot and ankle clinic with features of MN had their symptoms and clinical signs recorded. An ultrasound was subsequently performed by a radiologist who was kept blind to clinical findings.

Results: MN was detected on ultrasound at the site of symptoms in all but one case. Adjacent webspace neuromas were symptomatic in 27% and asymptomatic in 5%. Forefoot pain was the presenting feature in 96% and 72% characterised the pain as burning. 60% complained of altered sensation. The sensation of ´like having a pebble in the shoe´ was reported in only 52%. The thumb-index-finger squeeze test was the most consistent clinical finding (94%). Mulder’s click was only positive in 63% and was size dependent (10.9mm in positive tests vs. 8.5mm in negative tests, p=0.016). Other tests were less consistent and were positive in 42% for foot squeeze, 35% for plantar percussion, 31% for dorsal percussion and 28% for sensory changes.

Results: The diagnosis of MN can be reliably made through clinical assessment (98% chance of having an ultrasound detectable MN). A history of forefoot ‘burning’ pain with a positive thumb-index-finger squeeze test may be considered as pathognomonic of MN.