Joint Replacement | Spine | Trauma Solutions

Introduction

  • Compressive neuropathy of the interdigital nerve
  • Epidemiology
    • more common in females (9:1)
    • location
      • most frequently between the 3rd and 4th metatarsals
      • 2nd most common is between 2nd and 3rd metatarsal
  • Pathophysiology
    • poorly understood
      • Compression/tension around the transverse intermetatarsal ligament
      • Repetitive Microtrauma
      • Excessive Bursal Tissue
      • Endoneural Edema

 

Anatomy

  • 3rd and 4th inter-metatarsal space
    • unique anatomy in that medial branch of LPN and lateral branch of MPN merge and share a common perineum

 

Presentation

  • Symptoms
    • pain
      • 60% of patients report pain radiating into toe distally
      • often pain elicited during push-off phase of running athletes
      • shoes with narrow toe box or high heels can make symptoms worse
    • paresthesia
      • 40% report numbness or dysesthesia in plantar aspect of web space
  • Physical exam
    • Plantar tenderness with palpation just distal to metatarsal heads
    • A bursal click (Mulder’s click) may be elicited by squeezing metatarsals together

 

Imaging

  • Radiographs
    • Weight bearing views of foot to rule out bony deformity
  • MRI
    • indications
      • rule out other pathology
      • not required for diagnosis

 

Treatment

  • Nonoperative
    • wide shoe box with firm sole and metatarsal pad
      • indications
        • first line of treatment
    • corticosteroid injection
      • usually approached dorsal
      • nerve is below intermetatarsal ligament
  • Operative
    • neuroma resection
      • indications
        • when nonoperative management fails
      • technique
        • Dorsal incision used most commonly
        • Resection of neuroma 2-3 cm proximal to deep transverse intermetatarsal ligament (incise transverse intermetatarsal ligament)
        • Bury proximal stump within intrinsic muscles

 

Case

57/F with pain in the sole of the foot since 4 months.

OE: tenderness in between the 3rd and 4th metatarsal space

Operative findings :

Neuroma in the branch to 4th toe,

Branch to 3rd toe found to be normal

Neuroma resected and the branch to 3rd toe preserved.