High-yield overview
Intermetatarsal Nerve Entrapment
65% Cases3rd Web
8Female
PathognomonicMulder's
80-85% SuccessSurgery
10-15%Stump Neuroma
Web Space Involvement
3rd Web
PatternBetween 3rd and 4th metatarsals
Treatment65% of cases - most common
2nd Web
PatternBetween 2nd and 3rd metatarsals
Treatment30% of cases
4th Web
PatternBetween 4th and 5th metatarsals
Treatment3% of cases - rare
1st Web
PatternBetween 1st and 2nd metatarsals
Treatment2% of cases - very rare
Critical Must-Knows
- 3rd Web Space: Most common location (65%), followed by 2nd web (30%).
- NOT a True Neuroma: Perineural fibrosis from compression, not nerve tumor.
- Mulder's Click: Pathognomonic - palpable/audible click with lateral metatarsal squeeze.
- Conservative First: Wide shoes, metatarsal pad, corticosteroid injection (30-40% response).
- Surgical Neurectomy: Dorsal (most common) or plantar approach; expect permanent numbness.
Clinical Pearls
- "3rd web space most common (not 2nd)
- "Mulder's click is pathognomonic sign
- "Not a true neuroma - it's perineural fibrosis
- "Conservative fails in 60-70% - surgery indicated
- "Warn patient: numbness is EXPECTED after surgery
Clinical Imaging
Imaging Gallery
Key Exam Points - Morton's Neuroma
The 3rd web space is most common - NOT the 2nd.
- Mulder's Click: Compress metatarsal heads laterally while pressing web space plantarly. Positive = click + symptom reproduction.
- NOT a True Neuroma: Perineural fibrosis from compression, not neoplastic.
- Post-Op Numbness is EXPECTED: Warn patients they will have permanent numbness between affected toes after neurectomy.
- Stump Neuroma: Most common surgical complication (10-15%).
Morton's Neuroma vs Other Forefoot Pathology
| Feature | Morton's Neuroma | Metatarsalgia | MTP Synovitis |
|---|---|---|---|
| Web space (plantar) | Under MT heads | MTP joint | |
| Burning, shooting | Aching, pressure | Aching, swelling | |
| To adjacent toes | Local | Local | |
| Mulder's click +ve | Callus under MT | Drawer test +ve | |
| Removing shoes | Rest | Splinting |
3rd Web Space
Mulder's Click
Not a Neuroma
Stump Neuroma
At a Glance
Morton's neuroma is a compressive neuropathy of the common digital nerve, most commonly affecting the 3rd web space (65%), not the 2nd. It is NOT a true neuroma but rather perineural fibrosis from repetitive compression beneath the transverse metatarsal ligament, with an 8:1 female predominance. Patients report burning, shooting pain radiating to adjacent toes, often relieved by removing shoes. Mulder's click (palpable click with lateral metatarsal squeeze while pressing the web space) is pathognomonic. Conservative management (wide shoes, metatarsal pad, corticosteroid injection 30-40% response rate) is first-line. Surgical neurectomy (dorsal or plantar approach) achieves 80-85% good outcomes; permanent numbness between affected toes is expected and must be counseled. Stump neuroma (10-15%) is the most common surgical complication.
Mnemonic
3MBMorton's Neuroma - 3MB
| 3 | 3rd Web Most common location (not 2nd!) |
| M | Mulder's Pathognomonic click test |
| B | Burning Burning, shooting pain to toes |
| 3 | 3rd Web Most common location (not 2nd!) |
| M | Mulder's Pathognomonic click test |
| B | Burning Burning, shooting pain to toes |
Hook:3MB - 3rd web, Mulder's click, Burning pain. The three key features of Morton's neuroma.
Mnemonic
CLICKMulder's Test - CLICK
| C | Compress Compress metatarsal heads laterally |
| L | Locate Locate and press affected web space |
| I | Identify Identify palpable/audible click |
| C | Confirm Confirm symptom reproduction |
| K | Know Know it's pathognomonic |
| C | Compress Compress metatarsal heads laterally | C | Confirm Confirm symptom reproduction |
| L | Locate Locate and press affected web space | K | Know Know it's pathognomonic |
| I | Identify Identify palpable/audible click |
Hook:CLICK - perform Mulder's test to get the diagnostic click.
Mnemonic
SWIMTreatment Ladder - SWIM
| S | Shoes Wide toe box, low heel |
| W | Wedge/Pad Metatarsal pad proximal to heads |
| I | Injection Corticosteroid injection (30-40% relief) |
| M | Metatarsectomy Neurectomy if conservative fails |
| S | Shoes Wide toe box, low heel | I | Injection Corticosteroid injection (30-40% relief) |
| W | Wedge/Pad Metatarsal pad proximal to heads | M | Metatarsectomy Neurectomy if conservative fails |
Hook:SWIM through treatment - Shoes, Wedge pad, Injection, then (neuro)Mectomy.
Mnemonic
SNComplications - SNaP
| S | Stump Neuroma Most common (10-15%) |
| N | Numbness Expected - warn patient |
| P | Plantar Scar Painful scar if plantar approach |
| S | Stump Neuroma Most common (10-15%) |
| N | Numbness Expected - warn patient |
| P | Plantar Scar Painful scar if plantar approach |
Hook:SNaP - Stump neuroma, Numbness (expected), Plantar scar. Key complications to discuss.
Overview and Epidemiology
Morton's Neuroma (interdigital neuroma, Morton's metatarsalgia) is a common cause of forefoot pain representing compression neuropathy of the common digital nerve.
Terminology
- Misnomer: Not a true neuroma (not neoplastic)
- Correct Term: Interdigital nerve compression or perineural fibrosis
- Historical: Named after Thomas Morton (1876), though Durlacher described it earlier (1845)
Epidemiology
- Prevalence: 30% of patients with forefoot pain
- Gender: Female predominance 8:1 (high heels, narrow shoes)
- Age: 4th-6th decade most common
- Bilateral: 15-20% bilateral involvement
Web Space Distribution
- 3rd Web: 65% (between 3rd and 4th metatarsals) - MOST COMMON
- 2nd Web: 30% (between 2nd and 3rd metatarsals)
- 4th Web: 3% (rare)
- 1st Web: 2% (very rare)
- Multiple: 2-3% have involvement of more than one web space
Why 3rd Web Most Common?
- Junction of medial and lateral plantar nerve branches
- Nerve thicker at this level
- More tethered → less mobile → more susceptible to compression
Pathophysiology and Anatomy
Relevant Anatomy
Common Digital Nerves:
- Branches of medial and lateral plantar nerves
- Pass beneath transverse metatarsal ligament
- Divide into proper digital nerves to adjacent toes
3rd Web Space Peculiarity:
- Receives branches from BOTH medial and lateral plantar nerves
- Results in thicker, less mobile nerve
- More susceptible to compression
Pathophysiology
Compression Mechanism:
- Nerve passes between metatarsal heads
- Compressed against transverse metatarsal ligament (above)
- Metatarsal heads compress from sides
- Toe extension stretches nerve
Histopathology:
- Perineural fibrosis (NOT neoplastic)
- Demyelination and axonal degeneration
- Renaut bodies (subperineurial fibrosis)
- Endoneurial and epineurial fibrosis
- Small vessel thrombosis and arteriolar thickening
Risk Factors
- Footwear: High heels (transfers weight forward), narrow toe box
- Foot Type: Pes planus, hypermobile first ray
- Activities: Running, ballet, activities with repetitive forefoot loading
- Anatomical: Long metatarsals, tight intermetatarsal space
Clinical Features
History
Pain Characteristics:
- Location: Web space (plantar aspect)
- Quality: Burning, shooting, electric shock-like
- Radiation: To adjacent toes (3rd and 4th in 3rd web neuroma)
- Numbness: Tingling or numbness in affected toes
- Aggravating: Tight shoes, high heels, walking, prolonged standing
- Relieving: Removing shoes, massaging forefoot, rest
Red Flags for Alternative Diagnosis:
- Night pain (consider tumor, infection)
- Swelling (synovitis, gout)
- Constitutional symptoms
- Multiple toe involvement (peripheral neuropathy)
Physical Examination
Mulder's Test (Key Examination)
Technique:
- Hold foot with one hand around metatarsal heads
- Apply lateral compression (squeeze metatarsals together)
- With other hand, press affected web space from plantar to dorsal
- Positive = palpable/audible CLICK + symptom reproduction
Sensitivity/Specificity:
- Sensitivity: 62-98%
- Specificity: 95%
- Highly specific but variable sensitivity
Web Space Compression Test
- Direct pressure on affected web space (plantar and dorsal)
- Reproduces symptoms
- Less specific than Mulder's
Sensory Examination
- May have decreased sensation in adjacent toes
- Two-point discrimination may be abnormal
- Often normal early in disease
Investigations
Clinical Diagnosis
- Diagnosis is primarily CLINICAL
- Imaging not always required if classic presentation
- Used to confirm diagnosis or exclude other pathology
Ultrasound
Findings:
- Hypoechoic, ovoid mass in web space
- Often at level of metatarsal heads
- Dynamic compression may demonstrate lesion
Advantages:
- Widely available, low cost
- No radiation
- Dynamic assessment
- Operator-dependent
Size Threshold:
- Lesions more than 5mm are significant
- Correlation with symptoms improves with size
MRI
Indications:
- Atypical presentation
- Failed treatment (exclude other pathology)
- Preoperative planning for large or recurrent neuromas
Findings:
- T1: Low to intermediate signal mass
- T2: Low signal (fibrosis)
- Located between metatarsal heads
Diagnostic Injection
- Local anaesthetic injection into web space
- Relief confirms diagnosis
- Can be combined with corticosteroid for treatment
Clinical Pearl
Morton's neuroma is a CLINICAL diagnosis. Imaging confirms but a positive Mulder's click with classic symptoms is often sufficient for diagnosis and conservative treatment initiation.
Management
Algorithm
Non-Operative Management
First-Line - Shoe Modification:
- Wide toe box (MOST IMPORTANT)
- Low heel (under 2.5cm)
- Soft, cushioned sole
- Avoid pointed shoes
Metatarsal Pad:
- Placed PROXIMAL to metatarsal heads
- Spreads metatarsals apart
- Reduces nerve compression
- 50-60% improvement with shoe mods + pad
NSAIDs:
- Short-term symptom relief
- Not disease-modifying
Corticosteroid Injection:
- 30-40% long-term relief
- Temporary response common
- Technique: Inject into web space from dorsal
- Multiple injections increase risk of fat pad atrophy
- Maximum 3 injections recommended
Other Injections:
- Alcohol sclerosing injections (30% ethanol)
- Multiple sessions required
- Variable results (60-80% in some studies)
Expected Outcomes:
- 30-40% achieve adequate relief
- 60-70% eventually require surgery
- Conservative trial 3-6 months before surgery
Post-Operative Numbness is EXPECTED
Neurectomy involves excising the nerve, so permanent numbness between the affected toes is an EXPECTED outcome, not a complication. Patients MUST be counselled about this preoperatively to avoid dissatisfaction.
Complications
Surgical Complications
Morton's Neuroma Surgery Complications
| Complication | Incidence | Risk Factors | Prevention/Management |
|---|---|---|---|
| Stump neuroma | 10-15% | Insufficient proximal resection, traction | Adequate proximal cut, avoid tension |
| Numbness | 100% | Expected outcome (not complication) | Warn all patients preoperatively |
| Recurrence | 5-10% | Incomplete excision, adjacent web neuroma | Confirm diagnosis, adequate resection |
| Plantar scar pain | 5-8% | Plantar approach, hypertrophic scar | Prefer dorsal approach when possible |
| Wound infection | 2-3% | Diabetes, poor sterility | Standard perioperative antibiotics |
| Transfer metatarsalgia | 3-5% | Altered gait mechanics | Address forefoot mechanics, orthotics |
Stump Neuroma - Most Common Surgical Complication
Occurs in 10-15% of cases. The cut nerve end forms a painful neuroma at the stump. Prevention includes adequate proximal resection without excessive traction. Management includes revision surgery with more proximal resection into the plantar fat pad.
Numbness is Expected - Not a Complication
Neurectomy involves excising the nerve, so permanent numbness between the affected toes is an EXPECTED outcome. Patients MUST be counselled about this preoperatively to avoid dissatisfaction. This is not a complication but a predictable consequence of the procedure.
Special Considerations
Multiple Neuromas
- 2-3% have multiple web space involvement
- MRI helpful for preoperative planning
- May require staged surgery
- Higher risk of complications
Recurrent Morton's Neuroma
Causes:
- Stump neuroma (most common)
- Incomplete excision
- Adjacent web space neuroma (missed)
Management:
- Confirm diagnosis (MRI, diagnostic injection)
- Conservative measures first
- Revision surgery with proximal resection
- Consider plantar approach for better visualization
Differential Diagnosis
- Metatarsalgia: Pain under metatarsal heads, no radiation
- Stress Fracture: Point tenderness over bone, swelling
- MTP Synovitis: Joint swelling, positive Drawer test
- Freiberg's Disease: 2nd MT head AVN, adolescent female
- Plantar Plate Injury: MTP instability, Drawer positive
- Peripheral Neuropathy: Multiple toes, bilateral
Evidence Base
Level I (RCT)
Thomson et al - Methylprednisolone Injection RCT
Key Findings:
- 131 patients (85% female, mean age 53), ultrasound-guided injection
- Corticosteroid + anaesthetic vs anaesthetic alone (placebo)
- Global foot-health 14.1 VAS points better at 3 months (p=0.002)
- Neuroma size on ultrasound did not influence treatment effect
Clinical Implication: Corticosteroid injection gives symptomatic benefit for at least 3 months over placebo — supports its role as a first-line non-operative measure, but the effect is time-limited.
Source: J Bone Joint Surg Am, 2013
Level I (RCT)
Lizano-Diez et al - Steroid vs Local Anaesthetic RCT
Key Findings:
- 41 patients, double-blind, 3 injections each arm
- Corticosteroid + anaesthetic NOT superior to anaesthetic alone at 3 and 6 months
- 48.5% requested surgical excision by study end (44% vs 53%, p=1.0)
- Tempers expectations of durable benefit from steroid
Clinical Implication: The added benefit of corticosteroid over local anaesthetic alone is questionable beyond a few months, and roughly half of injected patients still progress to surgery.
Source: Foot Ankle Int, 2017
Level I (Systematic Review/Meta-analysis)
Matthews et al - Non-Surgical Interventions Meta-Analysis
Key Findings:
- 25 studies (7 RCTs, 18 case series); 8 interventions
- Corticosteroid injection reduced VAS pain vs control (WMD -5.3, 95% CI -7.5 to -3.2)
- Steroid superior to footwear/padding (OR 6.0, 95% CI 1.9 to 19.2)
- No single gold-standard non-surgical intervention identified
Clinical Implication: Corticosteroid injection and manual therapy have the strongest evidence among non-operative options, but overall evidence quality is modest — counsel realistically.
Source: J Foot Ankle Res, 2019
Level I (Diagnostic Meta-analysis)
Bignotti et al - Ultrasound vs MRI Meta-Analysis
Key Findings:
- 14 studies, surgery as reference standard
- Ultrasound sensitivity 0.91 vs MRI 0.90 (no significant difference, p=0.88)
- MRI pooled specificity 1.00; ultrasound 0.85
- Ultrasound is the most cost-effective first-line imaging
Clinical Implication: Ultrasound matches MRI for detection and is cheaper and dynamic — use it first; reserve MRI for atypical, recurrent or multi-space cases.
Source: Eur Radiol, 2015
Level IV (Case Series)
Lee et al - Neurectomy 10-Year Follow-up
Key Findings:
- 13 feet, mean 10.5-year follow-up after interdigital neurectomy
- VAS improved 8.6 to 2.4; good satisfaction in 61%
- 11/13 reported plantar numbness; 2 found it disabling
- Long-term results modestly worse than short/mid-term
Clinical Implication: Neurectomy gives durable pain relief, but expected numbness can itself be bothersome in a minority — explicit pre-operative counselling is essential.
Source: Foot Ankle Spec, 2011
Level IV (Prospective Case Series)
Kundert et al - Plantar Longitudinal Approach
Key Findings:
- 51 feet / 56 neuromas, mean 54-month follow-up
- VAS pain fell from 8 to 0.4 after plantar excision
- Complications 7.1%, scar problems 5.2%
- Plantar scar not bothersome if correctly positioned
Clinical Implication: A correctly placed plantar incision gives excellent relief with a low scar-problem rate, and is particularly useful for adjacent-space or recurrent neuromas where exposure matters.
Source: Foot Ankle Spec, 2015
Level IV (Case Series)
Ettehadi et al - Revision Neurectomy (Dorsal)
Key Findings:
- 25 feet, recurrent interdigital neuroma, mean 75-month follow-up
- Primary excision success quoted at ~74% in literature
- Revision via dorsal approach: 78% excellent/good (SEFAS)
- All re-excised masses confirmed neuroma histologically
Clinical Implication: Recurrent (stump) neuroma can be salvaged with revision dorsal excision and high satisfaction, though outcomes remain less predictable than primary surgery.
Source: Foot Ankle Surg, 2022
Level II (Economic Analysis)
Ross et al - Injection vs Surgery Cost-Effectiveness
Key Findings:
- Decision-analytic model after failed conservative care
- Sequential steroid then alcohol injection was the dominant strategy
- ICER $4402/QALY vs no treatment; favoured in 74% of simulations
- If alcohol success fell under 40%, steroid-only became most cost-effective
Clinical Implication: A trial of ultrasound-guided injections before surgery is cost-effective, supporting an injection-first pathway when conservative measures fail.
Source: AJR Am J Roentgenol, 2021
Guideline
AAOS / BOFAS Consensus - Diagnosis & Management
Key Findings:
- Diagnosis is primarily clinical (web-space pain, Mulder's sign)
- Imaging (ultrasound first-line) to confirm or exclude alternatives
- Stepwise care: footwear/orthoses then injection then surgery
- Counsel expected post-neurectomy numbness and stump-neuroma risk
Clinical Implication: Society guidance endorses a clinical diagnosis with a conservative-first, escalation pathway and mandatory counselling on permanent sensory loss.
Source: AAOS / British Orthopaedic Foot & Ankle Society guidance
Controversies & Areas of Uncertainty
- Does corticosteroid add anything over local anaesthetic? The 2013 Edinburgh RCT (Thomson) showed benefit over placebo, but the 2017 double-blind RCT (Lizano-Diez) found steroid no better than anaesthetic alone — the durable advantage of the steroid component remains contested.
- Neurectomy vs nerve-preserving surgery. Decompression (transverse intermetatarsal ligament release) avoids permanent numbness and stump neuroma but carries a higher recurrence risk; excision sacrifices sensation but is more definitive. The optimal choice is unsettled and patient-specific.
- Dorsal vs plantar incision. The dorsal approach avoids a weight-bearing scar and allows earlier mobilisation; the plantar approach gives superior exposure and, when correctly placed, a low scar-problem rate. High-level comparative evidence is lacking — largely surgeon preference.
- Size threshold for significance. A commonly cited cut-off is greater than 5mm, but symptoms correlate imperfectly with size and asymptomatic lesions are seen on imaging — imaging should confirm, not drive, the diagnosis.
- Minimally invasive alternatives. Alcohol sclerosing injection, radiofrequency ablation and cryoneurolysis show promise in case series but lack robust RCT support; reported success rates vary widely and reflect heterogeneous protocols.
- Bursa vs nerve. Whether the dominant pain generator is perineural fibrosis or an associated intermetatarsal bursitis is debated, which partly explains variable response to injection placement.
Viva Scenarios
Use these scenarios to practise clinical reasoning and management decisions
CLINICAL SCENARIOStandard
Classic Morton's Neuroma
CLINICAL PROMPT
"A 48-year-old woman presents with burning pain in the forefoot radiating to the 3rd and 4th toes. The pain is worse with high heels and relieved by removing her shoes. Mulder's click is positive."
PRACTICAL APPROACH
Diagnosis: This is a Morton's neuroma of the 3rd web space (classic presentation). Key findings: burning pain, radiation to adjacent toes, positive Mulder's click, exacerbated by footwear.
Pathophysiology: This is perineural fibrosis (NOT a true neuroma) from compression of the common digital nerve beneath the transverse metatarsal ligament. The 3rd web is most common as the nerve receives branches from both medial and lateral plantar nerves, making it thicker and less mobile.
Management:
- Conservative first:
- Shoe modification - wide toe box, low heel (most important)
- Metatarsal pad placed PROXIMAL to MT heads
- Corticosteroid injection if persists
- Surgery if fails conservative (3-6 months):
- Neurectomy via dorsal approach (avoid plantar scar)
- Excise neuroma proximal to MT heads
- 80-85% good outcomes
Counsel Patient:
- Numbness between 3rd and 4th toes is EXPECTED after surgery - permanent
- Stump neuroma risk 10-15%
KEY CLINICAL POINTS
3rd web space most common
Mulder's click is pathognomonic
Not a true neuroma - perineural fibrosis
Conservative first (shoes, pad, injection)
Surgery: dorsal neurectomy, warn about numbness
COMMON PITFALLS
Calling it a 'true neuroma' (it's perineural fibrosis)
Saying 2nd web is most common (it's 3rd)
Operating without conservative trial
Not warning about expected post-op numbness
FURTHER QUESTIONS
"What is Mulder's test?"
"What is the most common complication of surgery?"
"What approach would you use?"
CLINICAL SCENARIOStandard
Failed Conservative Treatment
CLINICAL PROMPT
"A 52-year-old woman has had Morton's neuroma symptoms for 9 months despite shoe modifications, metatarsal pad, and two corticosteroid injections. She wants to discuss surgical options."
PRACTICAL APPROACH
Assessment: This patient has failed adequate conservative treatment (9 months, shoe mods, pad, 2 injections). Surgery is now indicated.
Pre-Operative Workup:
- Confirm diagnosis - positive Mulder's click?
- Ultrasound or MRI to confirm lesion size, exclude other pathology
- Check for multiple web space involvement
- Assess adjacent toes for other pathology
Surgical Options:
- Dorsal Approach (Preferred):
- Longitudinal incision between 3rd and 4th MT heads
- Divide transverse metatarsal ligament
- Identify nerve, trace proximally, excise at least 3cm
- Allow nerve to retract into soft tissue
- Advantages: avoids plantar scar, early weight-bearing
- Plantar Approach (Alternative):
- Better visualization, reserved for revision or large neuromas
- Disadvantage: plantar scar pain 10-15%
Post-Operative Counselling:
- Numbness between 3rd/4th toes is EXPECTED and permanent
- Heel weight-bearing immediately, normal shoes 4-6 weeks
- 80-85% achieve good outcomes
- Stump neuroma risk 10-15%
KEY CLINICAL POINTS
Surgery indicated after failed conservative trial
Dorsal approach preferred (avoids plantar scar)
Divide transverse MT ligament, excise nerve proximally
80-85% success rate
MUST counsel about permanent numbness
COMMON PITFALLS
Not confirming diagnosis before surgery
Not discussing expected post-op numbness
Using plantar approach without good reason
Not mentioning stump neuroma risk
FURTHER QUESTIONS
"What are the advantages of dorsal approach?"
"How would you manage a stump neuroma?"
"What size lesion on imaging is significant?"
CLINICAL SCENARIOStandard
Recurrent Symptoms After Surgery
CLINICAL PROMPT
"A patient returns 6 months after Morton's neuroma excision with recurrent burning pain in the same web space. They are unhappy with the result."
PRACTICAL APPROACH
Differential Diagnosis:
- Stump Neuroma - most likely (10-15%)
- Incomplete excision
- Adjacent web space neuroma (missed)
- Other pathology (metatarsalgia, stress fracture)
Assessment:
- History: Was there a symptom-free interval? (suggests stump neuroma)
- Examination: Mulder's test, web space tenderness (may be more proximal)
- Imaging: MRI to identify stump neuroma location and size
- Diagnostic injection: Local anaesthetic to affected area
Management of Stump Neuroma:
- Conservative: May try injection, desensitization
- Revision Surgery: More proximal resection
- Plantar approach may provide better visualization
- Cut nerve in deep soft tissue to allow retraction
- Consider nerve capping or translocation to muscle
Prognosis:
- Revision surgery less predictable than primary
- 60-70% success with revision
- Manage patient expectations carefully
KEY CLINICAL POINTS
Stump neuroma is most common cause of recurrence
MRI helpful to locate stump neuroma
Revision surgery less predictable (60-70% success)
More proximal resection required
Manage expectations - outcomes less reliable
COMMON PITFALLS
Not considering stump neuroma as cause
Promising excellent results with revision (outcomes are worse)
Not imaging before revision surgery
Missing adjacent web space involvement
FURTHER QUESTIONS
"What is a stump neuroma?"
"What approach would you use for revision?"
"What other causes of recurrence should be considered?"
MCQ Practice Points
Classic Location Question
Q: Which intermetatarsal space is MOST commonly affected by Morton's neuroma?
A: 3rd web space (65%) - NOT the 2nd. This is a common exam trap. The 3rd common digital nerve receives branches from both medial and lateral plantar nerves, creating a larger and more susceptible nerve.
Pathology Definition
Q: What is the histological nature of Morton's neuroma?
A: Perineural fibrosis - NOT a true neuroma. The pathology shows fibrosis around the digital nerve, not proliferation of nerve tissue. This is why it's more accurately called "interdigital neuritis" or "intermetatarsal bursal swelling."
Clinical Examination
Q: What is Mulder's test and how is it performed?
A: Squeeze the metatarsal heads together with one hand while applying pressure in the interspace from plantar aspect. Positive test: Painful click (Mulder's click) as the neuroma subluxes between metatarsal heads. Sensitivity 60-80%.
Surgical Approach Decision
Q: What is the advantage of the dorsal approach over the plantar approach for neurectomy?
A: Dorsal approach avoids a plantar scar (weight-bearing surface) and allows immediate weight-bearing. The plantar approach has better direct visualization but requires non-weight-bearing for 3 weeks and risks painful plantar scarring.
Guidelines, Registries & Global Practice
Global Epidemiology
- One of the commonest causes of forefoot neuralgia worldwide; strongly associated with constrictive footwear and elevated heels
- Marked female predominance (commonly quoted around 8:1) across populations; peak in the 4th-6th decades
- 3rd web space dominates, followed by the 2nd; multiple/bilateral involvement in a minority
- Lower reported prevalence in habitually barefoot or wide-footwear populations, supporting a footwear-driven mechanical aetiology
Guidelines & Society Positions (Side by Side)
How Major Bodies Frame Morton's Neuroma
| Theme | AAOS / AOFAS (US) | BOFAS / NICE (UK) | EFORT / European consensus |
|---|---|---|---|
| Clinical first; Mulder's sign | Clinical; ultrasound as first imaging | Clinical with imaging confirmation | |
| Ultrasound (cost-effective) | Ultrasound preferred; MRI if atypical | Ultrasound or MRI (equivalent sensitivity) | |
| Footwear/orthoses, then injection | Footwear/metatarsal dome, then injection | Footwear, padding, injection trial | |
| After failed conservative trial | After failed conservative trial | After failed conservative trial | |
| Expected numbness, stump neuroma | Expected numbness, recurrence | Expected numbness, scar/recurrence |
Registry & Evidence Notes
- No dedicated implant registry applies (no implant is used); evidence is driven by RCTs (steroid injection) and surgical case series rather than arthroplasty-style registries
- Imaging meta-analysis confirms ultrasound is equivalent to MRI for detection and is the more cost-effective first-line test
- Economic modelling supports an injection-first pathway (steroid then alcohol) before surgery when conservative measures fail
High- vs Limited-Resource Practice Variation
- Well-resourced settings: ultrasound-guided diagnosis and injection, day-case dorsal neurectomy, MRI for atypical/recurrent cases
- Limited-resource settings: clinical diagnosis with Mulder's sign and footwear/padding emphasised; diagnostic local-anaesthetic injection substitutes for advanced imaging; surgery reserved for refractory disease
- Workforce: depending on jurisdiction, surgery is performed by orthopaedic foot-and-ankle surgeons or, where licensed, podiatric surgeons; complex/revision cases are typically referred to specialist foot-and-ankle units
MORTON'S NEUROMA
Clinical summary
KEY FACTS
- •3rd web space MOST COMMON (65%) - not 2nd!
- •NOT a true neuroma - perineural fibrosis
- •Female 8:1, 4th-6th decade
- •Burning pain radiating to adjacent toes
MULDER'S TEST
- •Squeeze metatarsals laterally
- •Press affected web space plantar to dorsal
- •Positive = CLICK + symptom reproduction
- •PATHOGNOMONIC (95% specificity)
CONSERVATIVE
- •Wide toe box shoes (MOST IMPORTANT)
- •Metatarsal pad PROXIMAL to MT heads
- •Corticosteroid injection (30-40% relief)
- •Trial 3-6 months before surgery
SURGERY
- •Neurectomy - dorsal approach (most common)
- •Divide transverse MT ligament, excise nerve
- •80-85% good results
- •Plantar approach: better view but scar risk
COMPLICATIONS
- •NUMBNESS is EXPECTED - warn patient
- •Stump neuroma 10-15% (most common complication)
- •Plantar scar pain if plantar approach
- •Recurrence 10-20%
EXAM TIPS
- •Always say '3rd web most common'
- •Call it 'perineural fibrosis' not 'neuroma'
- •Emphasize post-op numbness is EXPECTED
- •Know Mulder's technique