Definition
Benign enlargement of the common digital branch
- usually 3rd webspace
Anatomy
Found at level of or just distal to MT heads
- deep to the deep transverse MT ligament
Epidemiology
Classically women between 40 and 60
Aetiology
Can be traumatic but usually degenerative
Pathology
Demyelination of nerve fibres with fibrosis
History
Pain with weight bearing
- worse with wearing tight shoes
- in the ball of foot
- may be shooting type pain
Numbness / tingling in the affected toes
Examination
Mulder sign
- palpate webspace with fingers superiorly and inferiorly
- with other hand compress metatarsal heads together
- either palpate the lump or feel a click
Xray
Usually normal
- can have splaying of MT heads
US / MRI
Aid in confirming the diagnosis
Management
Non operative
Wide toe box
Metatarsal Pads
HCLA - Temporary relief
Sclerosing injections / phenol
- can solve problem
Operative
Options
- resection (dorsal or plantar)
- decompression
Resection Technique
Dorsal incision
- beginning at webspace edge
- separate MT with lamina spreader / retractor
- divide deep MT ligament / can preserve especially in athletes
- identify common digital nerve proximally
- identify neuroma / place forceps under
- resect proximal to neuroma
- resect distal to bifurcation
- send to pathology to confirm
Complications
Patient will have numbness
Painful stump neuroma (revise via plantar approach)
Hammer toe (inadvertant lumbrical resection)
Pain secondary to instability / division intermetatarsal ligament