Morton's Neuroma Flashcards
1
Q
What is Morton’s Neuroma?
A
- Compression neuropathy of INTERDIGITAL NERVE
2
Q
Describe its epiemiology?
A
- More common in females 9:1
- Most Frequent between 3rd/4th Metatarsals
- 2nd most common between 2/3rd Metatarsals
3
Q
What is the pathology of Morton’s Neuroma?
A
- Poorly understood
- COMPRESSION/ Tension around TRANSVERSE INTERDIGITAL LIGAMENT
- Repeptitive microtrauma
- Endoneural oedema
- Excessive bursal tissue
- All of the above can -> fibrosis
4
Q
What is the anatomy of the plantar nerves to the foot?
A
- From the tibial nerve
- Lateral plantar nerve supplies sole of little, 4th toes and 4/5 and 3/4 webspaces
- Medial plantar nerve supplies sole of great toe, 1st websapace and 2/3 web space
- Note the 3rd interspace recieves branches from noth medial and lateral plantar nerves
5
Q
What webspace has dual nerve supply?
A
- Between 3rd/4th Metatarsals- the third webspace
6
Q
What does a patient with Morton’s Neuroma present with?
A
Symptoms
- Pain- 60% -RADATION TO TOE DISTALLY
- Pain often DURING PUSH OFF
- Feelig like a stone on ball of foot
- PARATHESIA- 40% numbness/ dysesthesia plantar web space
Signs
- Plantar tenderness with palpation just DISTAL to METATARSAL heads
- A Mulder’s click ( bursa click) may be elicited when squeeze Metatarsals together
- Metatarsalgia, MTP synovitis or instability must be ruled out
7
Q
What investigations are helpful in DDX Morton’s neuroma?
A
- Xrays
- 3 weight bearing views of feet to rule out bony deformity
- MRI
- Rule out other pathology
- not required for diagnosis
- USS
- maybe helpful to evaluate nerve
- Dependent on size
- not necessary for diagnosis
8
Q
What is the DDx of Morton’s Neuroma?
A
- MT synovItis
- can mimic interdigital neuroma
- Tx of neuroma by steriod injection can exacerbate pathologic ocndition of MTP joint
- MT instability
9
Q
Describe tx of Morton’s Neuroma?
A
- Non operative
-
WIDE SHOE BOX, w FIRM SOLE, MT PAD
- first line of TX
-
CORTICOSTERIOD INJECTION
- Usually dorsal
- Nerve is below transverse mt ligament
- Avoid injecting MTPJ due to risk of iatrogenic instability
-
WIDE SHOE BOX, w FIRM SOLE, MT PAD
- Operative
- NEUROMA EXCISION
- when non op fails
-
NEUROMA DECOMPRESSION
- alternative to resection, esp in adjacent neuroma as excision would -> complete numb toe
10
Q
Describe surgical tx of Morton’s Neuroma?
A
NEUROMA EXCISION
- dorsal longitudinal incision in central web space incise fascia in line
- Incise TRANSVERSE METATARSAL LIG to reveal NEUROMA BENEATH
- EXCISE NEUROMA 2-3CM PROXIMAL to Transverse metatarsal ligament
- BURY STUMP IN INTRINSICS
11
Q
What are the surgical complications?
A
-
STUMP NEUROMA
- most common from **INADEQUATE RETRACTION **(traction neuritis)
- tethering of plantar neural branches that prevent retraction following resection
- INADEQUATE RESECTION ( not proximal enough)
- ** PAINFUL PLANTAR SCAR**- 5% increased risk cf dorsal