Morton neuroma

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

Ask the patient to point to the pain and name the toes that tingle. Typical symptoms arise in the third, less often second, web space, worsen in narrow shoes or high heels and feel like a hot pebble, electric shock or crumpled sock. Removing the shoe and rubbing the forefoot may help. Establish standing and running load, recent training change, diabetes, inflammatory disease, hallux valgus, previous injection and whether numbness is limited to adjacent toe surfaces or spreads across the sole.

Inspect standing alignment, toe splay, hallux valgus, lesser-toe deformity, callus and footwear. Palpate each metatarsal shaft, head, metatarsophalangeal joint and web space separately. Compress the forefoot while pressing the suspect space from plantar to dorsal; a click plus the patient's radiating pain supports the diagnosis, but an asymptomatic click is not diagnostic. Test plantar plates and joint drawer, calf length, tarsal tunnel, sensation, intrinsic power and pulses.

The diagnosis is often clinical. Weight-bearing AP, lateral and oblique radiographs do not show the nerve but identify metatarsal fracture, Freiberg change, arthritis and alignment that can produce metatarsalgia. Ultrasound is accessible and dynamic, differentiating a hypoechoic nerve lesion from a compressible bursa and guiding injection. Size alone correlates imperfectly with symptoms. MRI is used when ultrasound is inconclusive, multiple spaces or tumour are considered, or surgery requires clarification.

Begin by creating space: a wide and deep toe box, low heel and cushioned sole reduce transverse compression. Position a metatarsal dome just proximal to the metatarsal heads so it separates and unloads them; placing it directly under the painful web space can worsen symptoms. Trial taping or a prefabricated orthosis against walking or work goals. Modify repeated forefoot impact temporarily while maintaining tolerable conditioning, then rebuild calf and foot strength and activity exposure.

Topical NSAID may help surrounding mechanical pain but neural burning often responds incompletely. A targeted injection of local anaesthetic and corticosteroid can both support localisation and provide short-term relief. Ultrasound guidance helps accurate web-space placement and avoidance of plantar skin and vessels. Explain transient flare, skin change, fat-pad atrophy, hyperglycaemia, infection and recurrence. A short response is not a reason for indefinite repeat injection.

Persistent symptoms require diagnostic review before surgery. Re-examine the metatarsophalangeal joint and plantar plate, stress fracture, bursa, tarsal tunnel and lumbar source. Operative options include release of the transverse ligament with nerve preservation or excision of the diseased segment through dorsal or plantar approaches. Neurectomy predictably leaves numbness on facing toe surfaces. Scar sensitivity, infection, stiffness, persistent pain and stump neuroma must be understood.

Return to activity depends on wound, swelling, shoe tolerance, forefoot loading and underlying deformity rather than disappearance of the click. Podiatry can manage callus and orthotic placement. Diabetes and neuropathy require skin inspection because reduced sensation can hide pad or shoe injury. Peripheral arterial disease must be addressed before an invasive procedure. Smoking impairs wound healing. Anticoagulation needs a coordinated injection or surgical plan, never independent interruption.

During pregnancy, widening and fluid changes can alter footwear tolerance; begin with roomy shoes, pads and load strategies and select medicines or injection only after gestation-specific review. Older adults need insufficiency fracture and fat-pad atrophy considered. Bilateral several-space pain or prolonged morning stiffness should prompt inflammatory forefoot assessment rather than bilateral neuromas assumed from symptoms alone.

Key points

Morton neuroma causes burning or electric plantar forefoot pain radiating into adjacent toes, often described as a pebble in the shoe and relieved by removing tight footwear or massaging the foot.
The third web space is most commonly affected; local web-space tenderness and symptom reproduction with forefoot squeeze or a Mulder click support the diagnosis.
First-line investigation is a careful clinical examination including metatarsophalangeal joints, plantar plates, bony stress sites, sensation, pulses and footwear.
Weight-bearing radiographs exclude fracture, arthritis and metatarsal alignment disease; ultrasound is the preferred focused soft-tissue test when confirmation or injection planning is needed, with MRI for unresolved cases.
First-line management is a wide toe box, lower heel, reduced forefoot compression and a metatarsal pad placed proximal to the metatarsal heads, not directly beneath the painful nerve.
Progress calf flexibility, foot strength and activity load while treating coexisting hallux valgus, lesser-toe or metatarsophalangeal instability that alters forefoot pressure.
One ultrasound-guided local anaesthetic and corticosteroid injection can provide diagnostic and temporary therapeutic benefit; repeated injection risks plantar fat atrophy and nerve injury.
Refer persistent disabling, well-localised disease for decompression or neurectomy discussion, including expected adjacent-toe numbness, scar tenderness and stump-neuroma recurrence.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Interdigital nerve compression

Repeated forefoot compression beneath the deep transverse metatarsal ligament irritates a plantar digital nerve, most often in the third intermetatarsal space.

Footwear and load

A narrow toe box, high heel, repeated forefoot impact and some sports increase metatarsal crowding and symptoms without being the only cause.

Forefoot mechanics

Hallux valgus, lesser-toe instability, calf tightness and altered metatarsal loading can increase interdigital pressure and coexist with other pain generators.

Local bursal contribution

Intermetatarsal bursal inflammation lies close to the nerve and can produce or amplify a similar web-space pain syndrome.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Perineural fibrosis
Chronic mechanical irritation causes nerve degeneration and fibrotic thickening rather than a true proliferating nerve tumour, despite the name neuroma.
2
Compression during toe-off
Metatarsal heads approximate under narrow footwear and forefoot load, squeezing the thickened nerve and provoking burning radiation into adjacent toes.
3
Clicking displacement
Manual forefoot compression can displace the thickened nerve and bursa beneath the transverse ligament, creating a palpable or audible Mulder click.
4
Pain sensitisation and avoidance
Repeated neural pain leads to reduced toe-off and lateral loading, which may create callus, calf weakness and secondary metatarsalgia.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Pebble-in-shoe sensation

A burning plantar forefoot feeling with radiation into the facing surfaces of adjacent toes is the characteristic symptom description.

Web-space tenderness

Focal pain between metatarsal heads is more supportive than diffuse tenderness directly beneath every metatarsal head.

Mulder symptom reproduction

Forefoot compression with plantar pressure produces the patient's click and radiating pain, but a painless click is not sufficient.

Footwear relationship

Narrow toe-box or high-heeled shoes provoke symptoms that ease when the forefoot is released and massaged.

Red flags requiring action

An ulcer, spreading warmth, fever or immune compromise requires urgent forefoot infection assessment and pressure offloading.
Cool discoloured toes, rest pain, tissue loss or absent pulses requires vascular assessment before shoe, injection or operative treatment.
Focal metatarsal bony tenderness and pain after abrupt load increase suggests stress fracture even when early radiographs are normal.
Progressive constant numbness, motor weakness or symptoms extending beyond adjacent toes requires proximal nerve, tarsal-tunnel or spinal localisation.
A palpable enlarging mass, night pain or destructive imaging warrants tumour assessment rather than a routine neuroma pathway.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
First-line clinical forefoot examinationFirst stepFirst line
Why
Localise web-space neural pain and distinguish joint, plantar plate, bony, bursal and proximal nerve disease.
Interpretation and limitations
Concordant web tenderness and radiating squeeze pain support diagnosis; an incidental click without symptoms does not.
02
First-line weight-bearing foot radiographs when symptoms persistFirst line
Why
Assess metatarsal alignment, stress fracture signs, Freiberg disease, arthritis and deformity.
Interpretation and limitations
Normal films do not exclude neuroma or early stress fracture; imaging must be matched to focal examination findings.
03
Diagnostic ultrasound
Why
Confirm a symptomatic interdigital lesion, distinguish bursa or mass and guide accurate injection.
Interpretation and limitations
Correlate lesion size and compressibility with the exact symptomatic space because asymptomatic thickening occurs.
04
MRI for unresolved or complex forefoot pain
Why
Map several spaces, plantar plate, marrow, tumour and soft-tissue alternatives when ultrasound and examination disagree.
Interpretation and limitations
MRI is not automatically superior for a typical case and should precede surgery only when it changes localisation or procedure.
05
Diagnostic local-anaesthetic injection
Why
Test whether a precisely localised web space is the dominant pain source when several lesions coexist.
Interpretation and limitations
Temporary concordant relief supports localisation but does not guarantee durable steroid or surgical outcome.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Metatarsophalangeal synovitis

Joint-centred tenderness, swelling and pain with joint drawer or plantar-plate stress suggests synovitis or instability rather than web-space nerve pain.

Metatarsal stress fracture

Focal shaft or neck tenderness, training change and progressive weight-bearing pain require protective imaging even when the first radiograph is normal.

Intermetatarsal bursitis

Bursal fluid and dorsal web tenderness can closely mimic or coexist with neuroma and are distinguished by targeted ultrasound and examination.

Freiberg disease

Dorsal second or third metatarsal-head pain, stiffness and radiographic flattening or fragmentation indicates osteonecrosis and collapse.

Tarsal tunnel or radiculopathy

Broader plantar numbness, proximal provocation, weakness or reflex change localises neural symptoms above the interdigital space.

Additional chapter-specific clues

Joint alternative

Metatarsophalangeal swelling, drawer instability and plantar-plate tenderness localise pain to the joint rather than the interdigital nerve.

Proximal nerve alternative

Whole-sole sensory change, tarsal-tunnel provocation, weakness or radicular signs indicate a lesion above the web space.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01First-lineLocalise the symptomatic web spaceFirst stepFirst lineBurning forefoot pain radiates into adjacent toes without infection, vascular threat or acute fracture findings.

1Map web-space, joint, plantar-plate and metatarsal tenderness and reproduce the familiar symptom rather than a painless click.
2Assess standing deformity, callus, calf length, tarsal tunnel, sensation, pulses and the patient's actual shoes.
3Use weight-bearing radiographs when bony or alignment disease is plausible and ultrasound only when confirmation changes treatment.
4Explain that the lesion is fibrotic nerve irritation rather than a malignant tumour and agree a functional goal.

02Stepwise non-operativeCreate forefoot spaceA coherent neuroma pattern limits shoes, standing, walking or sport.

1Change to a wide deep toe box and lower heel and reduce only the specific repetitive forefoot load temporarily.
2Position a metatarsal pad proximal to the heads and adjust or remove it if it creates direct focal pressure.
3Progress calf flexibility, foot strength and walking or sport exposure while managing coexisting deformity and callus.
4Review symptom radiation and activity rather than lesion size after six to twelve weeks.

03InjectionUse precise temporary treatmentFootwear, pad placement and rehabilitation do not provide adequate function and the web space is well localised.

1Confirm absence of ulcer, infection and significant ischaemia and review diabetes and anticoagulation.
2Offer one ultrasound-guided local anaesthetic and corticosteroid injection with realistic duration and recurrence counselling.
3Use relief to progress shoe and load tolerance rather than returning immediately to compressive footwear.
4Reconsider joint, bursal, fracture and proximal nerve diagnoses before repeating a short-lived injection.

04SurgicalDecompress or excise refractory diseasePersistent disabling pain remains well localised despite credible non-operative and selected injection treatment.

1Confirm symptomatic level clinically and with imaging when needed and document other forefoot deformity that may require treatment.
2Discuss decompression versus neurectomy, approach, recovery, expected sensory change and uncertain complete pain relief.
3Explain scar pain, wound problems, infection, persistent metatarsalgia and stump neuroma.
4Plan postoperative shoe, swelling control and gradual forefoot loading with attention to skin and circulation.

Key medicines and prescribing safety2 treatments · regimens, roles and cautions

May reduce surrounding mechanical pain while footwear space and metatarsal unloading are corrected.

Topical diclofenac for associated forefoot pain

Spread 2–4 g of diclofenac 1.16% gel across intact painful forefoot skin per application, up to three or four applications daily for a short trial within the label maximum.

Avoid ulcers, broken or insensate uninspected skin and NSAID hypersensitivity, consider other NSAIDs and pregnancy, and do not expect topical treatment to reverse neural fibrosis.

Provides diagnostic localisation and temporary symptom reduction when shoe and pad treatment is insufficient.

Ultrasound-guided web-space corticosteroid injection

Under an aseptic trained local protocol, give one low-volume local anaesthetic and corticosteroid injection into the symptomatic intermetatarsal space, avoiding intraneural and plantar fat-pad placement, then review before any repeat.

Warn about flare, depigmentation, plantar fat atrophy, infection, nerve injury and transient hyperglycaemia; assess anticoagulation and never inject through ulcerated or infected tissue.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Persistent neuropathic pain

Burning forefoot symptoms can restrict shoes, standing, running and work and may persist despite removal of the original compression.

Transfer metatarsalgia

Avoided toe-off and coexisting deformity redistribute plantar load, causing callus and pain at neighbouring metatarsal heads.

Injection-related atrophy

Corticosteroid can thin plantar fat or depigment skin, increasing pressure pain even when neural symptoms temporarily improve.

Permanent sensory loss

Neurectomy intentionally produces numbness in the supplied adjacent toe sides, which must be discussed before surgery.

Stump neuroma

The divided nerve end can form a painful recurrent neuroma, while incomplete localisation may leave an unrecognised second pain generator.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

Track shoe tolerance, standing time, walking distance and radiation into the same adjacent toes rather than click alone.
Check metatarsal-pad position and skin after fitting and remove direct pressure promptly in neuropathy or vascular disease.
Re-examine metatarsophalangeal stability, focal bone tenderness and proximal neurology when improvement is absent.
After injection, record concordant anaesthetic response, duration of benefit, glucose where relevant and skin or sensory complications.
After surgery, monitor wound, swelling, scar sensitivity, expected numbness, recurrent neural pain and transfer metatarsalgia.
Advance forefoot impact only when cushioned-shoe walking and calf-foot loading are controlled without sustained flare.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Neuroma is a misnomer

The lesion is reactive perineural fibrosis and degeneration rather than a true neoplastic growth, which helps explain management and reassure patients.

A painless click proves little

Mulder clicking can occur without symptoms; the test matters when it reproduces the patient's exact web-space pain and radiation.

Pad position determines benefit

A dome placed behind the metatarsal heads spreads them, whereas one placed directly under the nerve becomes another compressive load.

Size does not equal symptoms

Small lesions can be painful and larger findings incidental, so ultrasound measurements cannot replace clinical concordance.

Numbness is part of neurectomy

Excision removes the sensory segment and predictably leaves altered sensation between the supplied toes, not merely as a complication.

The joint often mimics the nerve

Plantar-plate and metatarsophalangeal synovial disease sit beside the web space and must be tested separately before injection or excision.

11Common pitfallsFrequent interpretation and management errors.

01
Diagnosing Morton neuroma from diffuse metatarsalgia or a painless Mulder click without adjacent-toe radiation.
02
Placing a metatarsal pad directly beneath the painful web space and increasing compression.
03
Skipping weight-bearing radiographs and missing stress fracture, Freiberg disease or joint arthritis.
04
Repeating corticosteroid injections despite brief response and developing plantar fat-pad atrophy.
05
Offering neurectomy without explaining expected numbness, persistent pain and stump-neuroma risk.
06
Ignoring ulcer, arterial insufficiency or neuropathy before a pad, injection or surgical approach.