Physiotherapy for Morton's Neuroma

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Introduction

Civinini Morton’s Syndrome (CMS)is better known as Morton’s Neuroma. Weinfield and Myerson proposed the more correct term of “interdigital neuri- tis” histological examination reveals the presence of inflammatory tissue—that is, perineural fibrosis. Diagnosis is usually made through history taking and clinical examination but may be aided by ultrasonography and magnetic resonance imaging. Current nonoperative treatment strategies include shoe-wear modifications, custom made orthoses, and injections of local anesthetic agents, sclerosing agents, and steroids. Operative management options primarily involve either nerve decompression or neurectomy. We have reviewed the published literature to evaluate the outcomes of the available diagnostic modalities and treatment options and present an algorithm for clinical practice.

Clinically Relevant Anatomy

The common digital nerve and its branches in the third planter webspace are most commonly affected

benign perineural fibrosis of a common plantar digital nerve, typically within the third intermetatarsal space.

compressive neuropathy of the common plantar digital nerve

Aetiology

ischemia and mechanical compression of the plantar nerve against the transverse intermetatarsal ligament

chronic repetitive trauma, ischemia, entrapment, and intermetatarsal bursitis

It is a common cause of metatarsalgia leading to debilitating pain. It prefers the female gender, with a female to male ratio of 5:1 and an average age of 50 years at time of surgery. Precise aetiology remains under debate, with four etiopathogenetic theories often cited in the literature.

It affects about 30% of the population and

prefers the female sex, with a female to male ratio of 5:1 (2) and an average age of 50 years at time of sur- gery (3).

The pathology is bilateral in 21% of cases, affects the third intermetatarsal space (IMS) in 66% of cases, the second in 32%, known as Hauser’s Neuroma, and the fourth in 2%. Multiple locations are almost rare

Mechanism of Injury / Pathological Process

A thicker third intermetatarsal nerve formed by the fusion of the medial and lateral plantar nerves is more easily entrapped by the overlying intermetatarsal ligament. However, later studies revealed that other intermetatarsal spaces can also be affected

Morton's neuroma most likely represents an entrapment neuropathy causing perineural fibrosis, nerve degeneration, leukocyte infiltration, and epineural and endoneural vascular hyalinization that results in a significantly thicker intermetatarsal nerve

Such thickening can create further trauma that results in more thickening and subsequently more entrapment. Excessive weight bearing on the forefoot related to the use of high-heeled shoes has also been implicated and may explain the higher prevalence of Morton's neuroma in middle-aged women

most common in the third intermetatarsal space followed by the second

Clinical Presentation

clinically symptomatic

Clinically asymptomatic

pain or paresthesias in the intermetatarsal region worsened by weight-bearing or the use of high-heeled shoes, often relieved by removing shoes and gentle massage of the forefoot. On physical examination, a positive web space compression test or a painful palpable click (Mulder's sign) was considered suggestive of Morton's neuroma.

Patients classically experience sharp pain, a burning sensation, and paresthesias during weight bearing in the region of the intermetatarsal spaces. The pain is relieved by rest and shoe removal. On physical examination, a mass can be palpated in one third of patients. This finding is often accompanied by a characteristic click or Mulder's sign

The classical description of a Morton’s neuroma is paraesthesia within the affected digital nerve, accompanied by forefoot pain and is more commonly seen in females. 17% of patients describe some trauma to the foot resulting in symptoms.5 The most common characteristic of the pain is burning in nature. Altered sensations and feeling a “pebble in the shoe” is reported by more than 50% of patients. The pain is often exacerbated by walking, use of tight or heeled shoes and is reported by runners

no visual cues to the presence of a neuroma. Any deformity of the foot specially hallux valgus can lead to overcrowding of the toes and increased pressure on the lesser toes, and is therefore an important predisposing factor.

describe abnormal forefoot sensations such as a burning or ache . Pain localisation is most common in the plantar aspect of the forefoot, followed by the toe(s) and then the dorsal web space. Diagnosis can reliably be made based on clinical presentation and testing with ultrasound proposed as an accurate and cost-effective imaging method to confirm the diagnosis, especially in cases where the clinical diagnosis is equivocal . Ultrasound without a clinical diagnosis may lead to a false diagnosis of MN for asymptomatic interdigital nerve enlargements

Diagnostic Procedures

Ultrasound has high diagnostic accuracy for Morton's neuromas, and is frequently used to guide corticosteroid with local anaesthetic injection following the diagnostic scan. However, ultrasound is a highly operator-dependent imaging method, thus technique and experience are extremely important.
if there is any doubt of the diagnosis, an MRI scan is the gold standard investigation to identify a neuroma,

A positive digital nerve stretch test 1 and a positive Mulder’s click test

Outcome Measures

add links to outcome measures here (see Outcome Measures Database)

Management / Interventions

Footwear

staged care approach from wider, low heeled footwear and metatarsal paddingProperly fitted footwear with a wide toe box, low heel and a metatarsal pad

The first approach in the early stages of this condition usually begins with shoe modifications and orthotics, designed to limit the nerve compression. In order to prevent or delay the development of CMS, shoes should be sufficiently long, comfortable, broad toe-boxed, should bear a flat heel and a sufficiently thick external sole which should not be excessively flexible. Most authors suggested that an insole with medial arch support and a retrocapital bar or pad, just proximal to the metatarsal heads, displaces the pressure sites and can be beneficial to relieve the pain from the pinched nerve. A threshold period of 4.5 months appears to emerge from the results of the analysed studies, indicating that, beyond this period and in neuromas larger than 5-6 mm, orthotics and/or shoes modifications do not seem to give convincing results, proving to be more a palliation for the clinical condition to allow an acceptable life with pain rather than a real treatment.

Orthotics

The commonest form of treatment (initially) is the Metatarsal Bar. This insole, made by orthotists spreads the heads of the metatarsals to relieve pressure on the neuroma and thus improve symptoms. However, this does require the patient to wear broad toe box shoes and use the inserts so a degree of compliance is required. There is no evidence to support the use of inversion or eversion insoles, with studies demonstrating no significant improvement in patient reported outcomes

de Oliveira HAV et al The study demonstrated that customized insole with metatarsal and arch support relieved walking pain and improved patient-reported measures of function in patients with Morton’s neuroma.

Varus/valgus foot wedge a cobra style hard compressed felt padding adhered to the plantar surface of a fibreboard insole to supinate or pronate the foot. These were worn in the participant’s usual footwear (low heeled lace-up or loose fitting slip on shoes)

Steroid Injections

The use of therapeutic injections is very common in the management of Morton’s neuroma, and multiple therapies have been used. The injection can be guided by USS or done using a landmark technique. A randomised trial by Mahadevan et al did not show any statistical difference in patient outcomes after a steroid injection using USS or without.12 Santiago et al. noted that short term improvement in visual analogue scale (VAS) over 3 months in the group of patients having USS guided injections wa

Modality

extracorporeal shockwave therapy ESWT may reduce pain in patients with Morton's neuroma.

Manipulation/Mobilisation

Manipulation/mobilisation (involving distraction and plantarflexion of the metatarsophalangeal joints and mobilisation of other foot and ankle joints as required)

Study by Cashley and Cochrane once a week for 4 weeks followed by 2 further visits at 14-day intervals

Differential Diagnosis

The differential diagnosis includes intermetatarsal bursitis, true neuroma, inflammatory arthritis, pigmented villonodular synovitis, osteomyelitis, foreign body granuloma, stress fracture, Freiberg's infraction, and metatarsophalangeal joint dislocation.

Resources

add appropriate resources here