Morton's Neuroma Does Not Cause Toes to Spread Apart
Morton's neuroma does not cause the toes to spread apart. In fact, the opposite may be observed on imaging—when visible on radiographs, splaying of the metatarsals or soft-tissue density may be demonstrated, but this is not diagnostic and represents a radiographic finding rather than a clinical presentation 1.
Understanding the Pathology
Morton's neuroma is a benign perineural fibrosis of the common plantar digital nerve, typically occurring in the third intermetatarsal space (the webspace between the third and fourth toes) 2, 3. The condition results from:
- Entrapment or repeated microtrauma to the nerve
- Compression of the nerve between metatarsal heads
- Secondary fibrotic changes rather than a true neuroma
Clinical Presentation
Patients with Morton's neuroma present with characteristic symptoms that do not include toe spreading:
- Burning or shooting pain in the webspace that extends to the toes (sensitivity 54-57%) 4
- Sensation of "walking on a pebble" (sensitivity 43-53%) 4
- Subjective clicking reported by the patient (highly specific at 96%, positive likelihood ratio 13.14) 4
- Pain exacerbated by tight, high-heeled shoes 5
- Paroxysmal neuralgia so severe patients become anxious about weight-bearing 6
Key Diagnostic Features
The modified webspace tenderness test (thumb-index finger squeeze test) is highly sensitive (96%) with a low negative likelihood ratio (0.04), making it excellent for ruling out Morton's neuroma when negative 4.
Important Caveat
If you observe actual toe spreading or splaying in a patient, consider alternative diagnoses such as:
- Plantar plate tears (which can cause toe deviation and spreading)
- Metatarsophalangeal joint arthritis
- Interdigital bursitis
- Hallux valgus deformity
These conditions can be differentiated using MRI, which has 93% sensitivity and 68% specificity for Morton's neuroma 1, and can also identify plantar plate pathology with 95% sensitivity 1.