Morton's Neuroma Excision

Indication. Symptomatic Morton's neuroma — disabling forefoot pain localised to an intermetatarsal space with a positive Mulder's click and webspace point tenderness — that has failed conservative treatment for a minimum of 3–6 months and at least one, preferably two, corticosteroid injection trials. Imaging (ultrasound or MRI showing a lesion greater than 5 mm) supports the diagnosis but is not mandatory when the clinical picture is clear. Contraindicate surgery when the diagnosis is uncertain (diffuse forefoot pain without a focal finding), conservative care has not had a fair trial (less than 3 months), there is overlying skin breakdown or active infection, the forefoot is poorly perfused (peripheral arterial disease), or uncontrolled diabetic neuropathy masks the symptoms. Exhaust conservative care first. Before offering surgery, optimise each step: - Footwear — wide, deep toe box, heel height less than 4 cm. First-line and always re-checked (many patients are given correctly-shaped but wrongly-fitted shoes).

• Metatarsal pad or dome — placed proximal to the metatarsal heads to splay the interspace.
• Corticosteroid injection — ultrasound-guided into the webspace. A systematic review (Edwards 2021, 10 studies, 695 patients) found a moderate short- to medium-term benefit, superior to usual care but inferior to surgical excision; two injections are standard before recommending surgery, and more than two add limited benefit while risking plantar fat-pad atrophy and skin depigmentation.
• Sclerosing alcohol injection — an emerging option with mixed evidence. The largest series (Hughes 2007, 101 patients, mean 4.1 injections) reported 94% improved and 84% pain-free at a mean 21 months, but later cohorts showed substantial relapse and high-quality RCT data are lacking. Consent specifically for permanent numbness to the adjacent skin surfaces of the two toes in the cleft — this is the expected result of removing the nerve, not a complication — plus a realistic satisfaction figure (approximately 80–85% good or excellent at one year), stump neuroma (10–20%), and (for a plantar approach) a painful weight-bearing scar. The one decision that matters — dorsal or plantar. Both routes excise the neuroma reliably; the determinant of outcome is the adequacy of proximal excision, not the route. The choice is about the scar:

Setup. Supine with a sandbag under the ipsilateral buttock to rotate the foot to neutral, the foot at the end of the table for plantar access if needed. An ankle tourniquet (250 mmHg) is preferred over a thigh cuff — less blood in the field and less post-operative aching. Anaesthesia may be general, spinal, or an ankle block (deep peroneal, sural, saphenous and superficial peroneal nerves), which gives excellent post-operative analgesia.

The goal: expose the correct intermetatarsal space, divide the deep transverse metatarsal ligament to reach the neuroma lying plantar to it, confirm the neuroma, and excise the nerve cleanly at least 3 cm proximal to the bifurcation so the stump retracts into intrinsic muscle. The dorsal route is laid out below; the plantar alternative follows.

View larger

View larger

Rehabilitation | Phase | Timing | Mobilisation | Therapy / milestones | |-------|--------|--------------|----------------------| | 1 | 0–2 weeks | Dorsal: weight-bearing in a stiff-soled post-op shoe from Day 1. Plantar: non-weight-bearing on crutches | Bulky dressing changed at 48–72 h; elevation above heart level for 48 h; ankle-block analgesia | | 2 | 2–6 weeks | Dorsal: wide cushioned trainers at 2 weeks. Plantar: transition at 3–4 weeks | Suture or staple removal at 10–14 days; scar care (silicone gel, massage) from suture removal — vital after a plantar incision | | 3 | 6–12 weeks | Normal footwear; a metatarsal pad proximal to the heads during recovery | Standing work 3–4 weeks (dorsal) or 4–6 weeks (plantar); swimming at ~4 weeks; cycling 4–6 weeks | | 4 | 8–16 weeks | Full activity | Running at 8–12 weeks (dorsal) or 10–16 weeks (plantar) | Most patients note significant improvement within 4–6 weeks; full recovery is 8–12 weeks (dorsal) or 10–16 weeks (plantar). Permanent numbness of the cleft skin between the two toes is expected and normal — it is the direct result of removing the nerve, and patients should be counselled pre-operatively so they do not report it as a complication. Overall satisfaction for primary excision is approximately 80–85% good or excellent. Follow-up. Wound check and suture removal at 2 weeks; review at 6 weeks (pain, function, footwear tolerance); final review at 12 weeks, arranging ultrasound or MRI only if symptoms persist or recur. Complications

Revision surgery principles. Always obtain MRI or ultrasound before revision to locate a residual or stump neuroma, confirm the space, and exclude alternatives (MTP synovitis, Freiberg's infraction, plantar plate tear, stress fracture). The plantar approach is preferred in revision — it avoids the dorsal scar and gives proximal access through virgin tissue. At revision, excise the stump further proximally and bury the new cut end deeply into intrinsic muscle or between the metatarsal shafts; centrocentral neurorrhaphy is a described option to prevent end-bulb formation. Counsel the patient that revision outcomes are substantially inferior to primary surgery.

Epidemiology. Morton's neuroma predominantly affects women (female-to-male ratio approximately 5:1) in the fourth to sixth decades. The 3rd webspace accounts for approximately 70% of cases and the 2nd webspace for 15–20%; true simultaneous bilateral neuromas occur in less than 5%. High-heeled, narrow footwear is the strongest modifiable risk factor. Pathoanatomy. The lesion arises from chronic perineural fibrosis of the common plantar digital nerve, driven by repetitive microtrauma and compression between adjacent metatarsal heads during toe dorsiflexion. The traditional teaching — that a communicating branch from the lateral plantar nerve makes the 3rd webspace nerve thicker and so more prone to neuroma — is not supported by the best anatomical evidence. Levitsky's cadaveric study of 71 feet found the communication present in only 27%, the 3rd-webspace nerve was not thicker when it existed, and neuroma incidence was no greater. The favoured explanation is mechanical: the intermetatarsal head distance (and the head-distance-to-nerve-diameter ratio) is significantly smaller in the 2nd and 3rd spaces, predisposing both to compression. Dorsal versus plantar — the evidence. The definitive comparative study is the prospective RCT by Akermark and colleagues (Foot & Ankle Int 2013), which randomised 76 patients (93% follow-up to a mean of 34 months) to a plantar or dorsal incision. Contrary to a widely repeated misconception, this Level I trial found no significant difference between the routes in pain at daily activities, restriction of activities, or scar tenderness — good outcomes in 87% (plantar) and 83% (dorsal), pain reduced 96–97% in both. The only meaningful difference was the type of complications, not overall outcome. Where the evidence does favour a route it favours dorsal: the Cochrane review (Thomson 2004) found limited evidence that dorsal incisions produce fewer symptomatic post-operative scars, and Faraj's comparative series reported fewer scar problems and faster rehabilitation dorsally. The practical conclusion is that both routes give equivalent excision when performed correctly, and the determinant of outcome is the adequacy of proximal nerve excision — which is why most surgeons default to the dorsal route for its scar advantage. Conservative injection evidence. A systematic review of a single corticosteroid injection (Edwards 2021, 10 studies, 695 patients) found a moderate short- to medium-term benefit superior to usual care but inferior to surgical excision, with a very low adverse-event rate — justifying one to two injection trials before surgery. Sclerosing alcohol injection (Hughes 2007, 101 patients) gave 94% improved and 84% pain-free at a mean 21 months, but longer-term cohorts show relapse and high-quality RCT data are lacking.