Morton’s Neuroma

Normal Anatomy Intermetatarsal plantar nerves are terminal branches of the medial and lateral plantar nerves Run into the webspace plantar to the intermetatarsal ligaments Each nerve passes within the plantar aponeurosis and splits into 2 branches supplying the skin The 3rd common nerve receives a large communicating branch from the lateral plantar nerve which passes deep to the deep transverse metatarsal ligament at the 3rd web space

Pathology Benign neuroma (a growth of neural tissue) or irritation of an intermetatarsal plantar nerve Causes neuropathic pain most commonly the 2nd and 3rd metatarsal spaces

Mechanism of Injury Insidious Chronic Trauma Theory Ischemia Theory Multiple different theories that may be occurring in isolation or concurrently Chronic Trauma Theory Repetitive trauma to the forefoot and plantar intermetatarsal structure Dorsiflexion of the toes and contraction of the flexor digitorum brevis stretches intermetatarsal plantar nerves causing repeated traction Ischemia Theory Degenerative changes to the plantar digital arteries Intermetatarsal Bursitis Theory Inflammation of a bursa in the 2nd and 3rd webspace can cause fibrosis of the adjacent nerve Entrapment Theory Intermetatarsal nerve becomes trapped by the anterior edge of the deep transverse metatarsal ligament Pronation Theory During over-pronation the 3rd intermetatarsal space is reduced leading to neural compression

Subjective Examination Pain, burning or tingling on the plantar aspect of the foot Usually the 3rd webspace Worse with wearing tight shoes Relieved by rest or removing the shoe

Objective Examination Tenderness direct palpation of the web space of the toes Tenderness on stretching of the web space of the toes Reduced sensation in between the affected toes

Special Tests Mulder’s Click Tinel- Hoffman sign Audible or palpable ‘click’ with exacerbation of pain when side compression is applied to the metatarsal heads whilst isolating the painful web space using the other hand Tinel- Hoffman sign Pins and needles over a nerve trunk on tapping the suspected web space of the foot

Further Investigation Ultrasound MRI

Management Aim is to reduce pressure, inflammation and nerve irritation Surgery is often considered before conservative interventions

Conservative Reduce pain and inflammation Massage Ice NSAID’s Orthotics Wide flat shoes Restore Normal Range of Movement Ankle and Foot Soft tissue massage Foam rolling Stretching Dry needling Joint mobilisations Joint manipulations Neurodynamic mobilisations Restore Normal Muscle Activation Intrinsic foot muscles

Plan B Corticosteroid injection Decompression Surgery Neurectomy

References Jain, S. and K. Mannan (2013). "The diagnosis and management of Morton's neuroma: a literature review." Foot Ankle Spec 6(4): 307- 317. Pastides, P., S. El-Sallakh and C. Charalambides (2012). "Morton's neuroma: A clinical versus radiological diagnosis." Foot Ankle Surg 18(1): 22-24. Sault, J. D., M. V. Morris, D. J. Jayaseelan and A. J. Emerson-Kavchak (2016). "Manual therapy in the management of a patient with a symptomatic Morton's Neuroma: A case report." Man Ther 21: 307- 310.