Morton’s neuroma

• Intermetatarsal disorder
• Morton’s metatarsalgia
• Plantar nerve lesion

• 355.6 Lesion of plantar nerve

• G57.6 Lesion of plantar nerve
• G57.60 Lesion of plantar nerve, unspecified lower limb

• 4E: Impaired Joint Mobility, Motor Function, Muscle Performance, and Range of Motion Associated with Localized Inflammation

Description

• Painful condition that affects the ball of the foot
• Growth of scar tissue from chronic irritation of compression
• Most common area is between the 3rd and 4th toes, but also can be in between the 2nd and 3rd toes
• Involves a thickening of the tissues (neuroma) around one of the intermetatarsal plantar nerves
• Branches from the medial and lateral plantar nerves
• May alter mechanics during the push-off phase of gait

Essentials of Diagnosis

• Can be an independent diagnosis and not associated with a disease process
• Characterized by numbness, burning, and pain
• Sometimes relieved by removing shoes
• No visible deformity
• Higher risk for individuals with bunions and flat feet

General Considerations

• Feeling like you are stepping on something like a pebble
• A burning pain in the ball of the foot that radiates to the toes
• Tingling or numbness in the toes
• Titled a neuroma, but is not a tumor formation as “oma”

Demographics

• Ladies wearing high heels
• Rock climbers with repetitive forefoot pressure

Signs and Symptoms

• Burning pain in the ball of the foot
• Numbness and tingling in the toes, especially between the 3rd and 4th toes
• Difficulty wearing/finding shoes, especially pointy ones
• Limited motion of the MTP joint

Functional Implications

• Pain with standing
• Pain with ambulation at the toe
• Inability to wear regular shoes
• Need to wear larger shoes with a larger toe box
• Alteration of gait pattern and mechanical issues of the forefoot

Possible Contributing Causes

• Poor footwear: improper fit
  • Toe comes to a point (boots)
  • Narrow forefoot (high heels)
• Certain sports
  • Repetitive trauma from high-impact activities, such as jogging or running
  • Those requiring tight shoes, such as snow skiing or rock climbing
• Foot deformities: bunions, hammer toes, flat feet, excessive flexibility

Differential Diagnoses

• Metatarsalgia
• Metatarsal stress fracture
• Capsulitis
• Synovitis
• Stress fracture
• Tendinitis
• Degenerative arthritis
• Bursitis
• Lumbar radiculopathy
• Freiburg’s disease: osteochondritis of the metatarsal head

Imaging

• X-ray
• Diagnostic ultrasound
• MRI

Diagnostic Procedures

• Mulder’s Sign (Pinch Test)2: Lateral squeezing of the forefoot with one hand and the opposite hand pushing up on the nerve

• Rule out fracture
• Reveal soft tissue abnormalities
• Mulder’s Sign2: A positive test is a click or snap at the nerve with severe pain