The diagnosis and management of Morton's neuroma: a literature review

Morton's neuroma: who, when and how contributed to its description and treatment?

PURPOSE

The interdigital nerve neuroma of the forefoot is commonly known as Morton's Neuroma. Many authors have described and treated this condition before and after Morton. This study aims to investigate the past scientific literature to better understand what comprehension and treatments have been used to master this pathology.

METHODS

Historical and modern scientific accounts were searched for descriptions of interdigital nerve neuroma or metatarsalgia (as some authors described it) to have a thorough overview of the subject. The scientific literature was searched to highlight the evolution of the nomenclature and to summarise historical and current treatments, especially conservative ones.

RESULTS

Influential authors described the interdigital nerve neuroma and its symptoms. Durlacher, the King's podiatrist in England in the 1800s, was the first to understand that this was a neuralgic affection; with his practical approach, he treated the Neuroma using pressure-relieving footwear. The first anatomical description should be credited to the Italian anatomist Civinini. Morton, the American Civil War surgeon, was the first to understand the aetiology of pain better and the first to propose a surgical treatment to relieve symptoms. Tubby, the British alpine climber, linguist, archaeologist and orthopaedic surgeon, observed a nodular mass on the third common digital nerve and proposed surgical treatment with resection of the metatarso-phalangeal joint.

CONCLUSION

the use of a term widely accepted and recognised by all its users with a precise meaning and symbolisation makes it easily understandable and lasting. Also, if it is known that what is called Morton's neuroma is not a neuroma but a benign perineural fibrosis of a common plantar digital nerve, the use of the terminology Morton's neuroma is still universally accepted and recognised.

Retrospective Study of Morton's Neuroma: Clinical, Paraclinical, and Therapeutic Assessment of 10 Cases

Background Morton's neuroma is a common cause of forefoot pain, typically occurring in the third metatarsal space and characterized by symptomatic nerve compression. This condition often leads to significant functional impairment, affecting weight-bearing activities and limiting appropriate footwear due to pain and discomfort. Objective This study aims to evaluate the outcomes of conservative interventional treatment for Morton's neuroma, specifically focusing on corticosteroid injections. Methodology We reviewed 10 cases of Morton's neuroma in the field of physical medicine and rehabilitation. The average age of the patients was 45 years, with a higher prevalence among females. Diagnoses were confirmed through clinical assessment and ultrasound imaging. Results All 10 patients (100%) received conservative interventional treatment with corticosteroid injections. This approach effectively alleviated symptoms in 9 out of 10 patients (90%). Surgical options were considered only if symptoms did not improve with this treatment. Conclusions All 10 patients (100%) were treated with corticosteroid injections, which alleviated symptoms in 9 out of 10 patients (90%). Surgical options were considered only if this treatment was insufficient. This analysis highlights the effectiveness of this approach as a first-line management strategy for Morton's neuroma.

Diagnostic Accuracy of Subjective Features and Physical Examination Tests for Morton Neuroma: A Systematic Review

Background

Morton neuroma (MN) is a common pathology with many reported subjective features and physical examination tests. The objective of this systematic review was to examine the diagnostic accuracy of subjective features and physical examination tests for MN.

Methods

CINAHL, CENTRAL, EMBASE, MEDLINE, PubMed, Opengrey, PEDro, PsycINFO, Scopus and Trials register were searched in January 2021. Two reviewers independently screened studies for inclusion using the following criteria: (1) prospective or retrospective cohort studies, (2) participants aged ≥18 years with suspected MN, (3) primary data allowing construction of 2 × 2 diagnostic table or reported sensitivity and specificity figures, (4) diagnosis of MN using magnetic resonance imaging, ultrasonography, surgery, positive response to steroid and/or anesthetic injection, and (5) in English or translatable. Quality of included studies was assessed using the Quality Assessment for Diagnostic Accuracy Studies version-2 (QUADAS-2) tool.

Results

The search yielded 1170 results, of which 9 were included in this systematic review. Narrative synthesis revealed that subjective clicking reported by a patient was highly specific (0.96) and had a high positive likelihood ratio (13.14). The modified webspace tenderness test (thumb index finger squeeze test) was highly sensitive (0.96) with a low negative likelihood ratio (0.04). The commonly reported feeling of "walking on a pebble" and "burning pain" had sensitivities of 43% to 53% and 54% to 57% and associated specificities of 52% and 48%, respectively.Only 1 study had low risk of bias. The review was limited by the number of studies that included few or no patients without MN, and the impact this had on the ability to calculate diagnostic accuracy.

Conclusion

There is strong evidence that clicking reported by a patient rules in MN and that the modified webspace tenderness test rules out MN when negative.

Rare entrapment neuropathies of the lower extremity: A narrative review

Lower limb entrapment neuropathies comprise a wide range of disorders, including less common conditions like tarsal tunnel syndrome, Morton neuroma, obturator nerve entrapment syndrome, superior gluteal nerve entrapment, and cluneal nerve entrapment syndrome. Despite being less prevalent, these syndromes are equally significant, presenting with symptoms such as pain, dysesthesia, muscular weakness, and distinct physical signs. Accurate diagnosis of these less common disorders is crucial for successful therapy and patient recovery, as they can sometimes be mistaken for lumbar plexopathies, radiculopathies, or musculotendinous diseases. This narrative review highlights the significance of identifying and diagnosing these particular neuropathies through a comprehensive assessment of the patient's medical history, detailed physical examination, and the use of electrodiagnostic and/or ultrasound investigations. When the diagnosis is uncertain, advanced imaging techniques like magnetic resonance neurography or magnetic resonance imaging are necessary to confirm the diagnosis. A positive diagnosis ensures prompt and targeted treatments, preventing further nerve impairments and muscle wasting. This article explores the epidemiology, anatomy, pathophysiology, etiology, clinical presentation, and electrodiagnostic interpretation of lower limb entrapment neuropathies, highlighting the importance of precise diagnosis in achieving favorable patient outcomes.

A Characteristic Magnetic Resonance Imaging Finding to Identify Morton Neuroma: The Slug Sign

Background

Morton neuroma is a common cause of forefoot pain and sensory disturbances, but it is difficult to identify on magnetic resonance imaging (MRI). The aim of this study was to verify the usefulness of a characteristic MRI finding (slug sign) for identifying Morton neuroma and to clarify the relationship between excised neuroma characteristics and preoperative MRI findings.

Methods

Twenty-two web spaces were retrospectively assessed from the second and third intermetatarsal spaces of 11 feet of 10 patients (7 women and 3 men, aged average 59.5 years) who underwent surgical excision of Morton neuroma between 2017 and 2022. Asymptomatic web spaces were used as control. Neuromas with 2 branches of the plantar digital nerves on axial T1-weighted MRI (MRI-T1WI) were considered the slug sign. We investigated the preoperative presence of the slug sign in Morton neuroma and asymptomatic control web spaces. We also investigated the relationship between the maximum transverse diameter of the excised specimen and that estimated on coronal MRI-T1WI.

Results

A total of 15 Morton neuromas were excised and assessed. The slug signs were present in 10 intermetatarsal spaces in 15 web spaces with Morton neuroma whereas the sign was found in 1 intermetatarsal space in 7 asymptomatic web spaces. The sensitivity and specificity for the slug sign to diagnose Morton neuroma was 66.7% and 85.7%, respectively. The positive and negative predictive values were 90.9% and 54.5%, respectively. The mean maximum transverse diameter of excised neuromas was 4.7 mm. The mean maximum transverse diameter of neuromas on coronal MRI-T1WI was 3.4 mm. A significant positive correlation was found between the maximum transverse diameters of excised specimens and diameters estimated on coronal MRI-T1WI (r = 0.799, P < .001).

Conclusion

The slug sign may be a useful indicator of Morton neuroma on MRI to confirm nerve involvement after bifurcation.

Level of Evidence

Level IV, retrospective series.

Effect of surgical approach on the treatment of Morton's neuroma: a systematic review and meta-analysis

BACKGROUND

Surgical resection of Morton's neuroma includes dorsal and plantar approaches. However, there is no consensus on the choice of approach in clinic. The purpose of this study was to conduct a systematic review and meta-analysis to compare the surgical results of dorsal and plantar approaches.

METHODS

The literatures of PubMed, Cochrane library, Embase and Web of Science were searched on April 26th, 2023. A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The data were extracted after screening the literature and evaluating the quality of the methodology included in the study. The RevMan5.4 software was used to analyze and calculate the OR value and 95% confidence interval.

RESULTS

A total of 7 randomized controlled trials and comparative studies were published, of which only 5 were included. There were 158 feet via plantar approach (plantar group, PG) and 189 via dorsal approach (dorsal group, DG). There was no significant difference between PG and DG in overall adverse events, sensory problems, incision infection and deep vein thrombosis (p > 0.05). In terms of scar problems, PG showed more than DG (OR, 2.90[95%CI, 1.40 to 5.98]; p = 0.004). Other outcome indicators such as visual analogue scale (VAS) scores and American Orthopedic Foot and Ankle Society (AOFAS) scores were difficult to be included in the comparison.

CONCLUSIONS

Based on the relatively low quality and small amount of available evidence, the meta-analysis conducted produces a hypothesis that the frequency of adverse events in surgical treatment of Morton's neuroma, dorsal approach and plantar approach may be the same, but the types are different. More high-level evidence is needed to further verify this hypothesis.

Comparing Clinical Examination and Radiological Evaluation in the Preoperative Diagnosis and Location of Symptomatic Interdigital (Morton's) Neuroma

This study investigates whether clinical examination is as sensitive as ultrasound and magnetic resonance imaging (MRI) in the diagnosis and localization of symptomatic interdigital neuroma. A retrospective cohort study was conducted at two tertiary centers on all consecutive patients who underwent excision by a single foot and ankle specialist surgeon for a presumed interdigital neuroma between January 2008 and December 2020. Investigators collected preoperative clinical findings, radiological investigations, and postoperative outcomes. Sensitivity and positive predictive values were calculated and Z-score for 2 populations proportions was performed. One hundred fourteen consecutive patients were operated on for 131 suspected interdigital neuroma. Thirteen patients were excluded due to lack of adequate clinical documentation. Of the remaining 101 patients with 118 suspected interdigital neuroma, 115 were confirmed histologically (97.5%). The sensitivity of clinical assessment to accurately diagnose and place an interdigital neuroma in the correct space was calculated as 96.5%. The most common preoperative clinical feature was pain (99.2%). The calculated sensitivity for ultrasound to accurately diagnose an interdigital neuroma was 83.6%, and to correctly locate neuroma was 79.5% respectively, which were both statistically different compared to clinical assessment (p value: <.001 and p value: <.001). The calculated sensitivity for MRI to accurately diagnose an interdigital neuroma was 93.6%, which was statistically different to clinical assessment (p value: .005). Preoperative clinical assessment has the highest sensitivity to accurately diagnose interdigital neuroma when compared to MRI and ultrasound. Preoperative clinical assessment has higher sensitivity to accurately locate interdigital neuroma when compared to ultrasound.

Is Morton's neuroma in a pes planus or pes cavus foot lead to differences in pressure distribution and gait parameters?

Morton's neuroma (MN) is a compressive neuropathy of the common digital plantar nerve causing forefoot pain. Foot posture and altered plantar pressure distribution have been identified as predispoing factors, however no studies have compared individuls with different foot postures with MN. Thus, we aimed to compare the effect of MN on spatiotemporal gait parameters and foot-pressure distribution in individuals with pes planus and pes cavus. Thirty-eight patients with unilateral MN were evaluated between June and August 2021. Nineteen patients with bilateral pes planus and 19 age and gender-matched patients with pes cavus who had no prior surgery were recruited. A Zebris FDM-THM-S treadmill system (Zebris Medical GmbH, Germany) was used to evaluate step length, stride length, step width, step time, stride time, cadence, velocity, foot-pressure distribution, force and whole stance phase, loading response, mid stance, pre-swing and swing phase percentages. There were no significant differences between the groups in spatiotemporal gait parameters (p > 0.05). Patients with pes planus displayed the following results for step length (49.36 ± 8.38), step width (9.05 ± 2.12), stance phase percentage (65.92 ± 2.11), swing phase percentage (34.08 ± 2.12), gait speed (2.96 ± 0.55), and cadence (100.57 ± 8.84). In contrast, patients with pes cavus displayed the following results for step length (49.06 ± 8.37), step width (8.10 ± 2.46), stance phase percentage (64.96 ± 1.61), swing phase percentage (34.79 ± 1.60), gait speed (2.95 ± 0.65), and cadence (99.73 ± 13.81). Foot-pressure distribution values showed no differences were detected in force, forefoot, and rearfoot pressure distribution, except for midfoot force (p < 0.05). The forefoot, midfoot, and rearfoot pressure values for the pronated group were 32.14 ± 10.90, 13.80 ± 3.03, and 22.78 ± 5.10, and for the supinated group were 33.50 ± 11.49, 14.23 ± 3.11 and 24.93 ± 6.52. MN does not significantly affect spatiotemporal gait parameters or foot-pressure distribution in patients with pes cavus or pes planus.

Diagnostic Considerations of Intermetatarsal Bursitis: A Systematic Review

Intermetatarsal bursitis (IMB) is an inflammation of the intermetatarsal bursas. The condition causes forefoot pain with symptoms similar to those of Morton's neuroma (MN). Some studies suggest that IMB is a contributing factor to the development of MN, while others describe the condition as a differential diagnosis. Among patients with rheumatic diseases, IMB is frequent, but the scope is yet to be understood. The aim of this paper was to investigate the diagnostic considerations of IMB and its role in metatarsalgia by a systematic review approach. We identified studies about IMB by searching the electronic databases Pubmed, Embase, Cochrane Library, and Web of Science in September 2022. Of 1362 titles, 28 met the inclusion criteria. They were subdivided according to topic: anatomical studies (n = 3), studies of patients with metatarsalgia (n = 10), and studies of patients with rheumatic diseases (n = 15). We conclude that IMB should be considered a cause of pain in patients with metatarsalgia and patients with rheumatic diseases. For patients presenting with spreading toes/V-sign, IMB should be a diagnostic consideration. Future diagnostic studies about MN should take care to apply a protocol that is able to differ IMB from MN, to achieve a better understanding of their respective role in forefoot pain.

Complications of alcohol injections for Morton’s neuroma

Introduction

Morton’s neuroma (MN) is a neuropathic metatarsalgia that causes pain in the plantar aspect of the forefoot generally between the third and fourth metatarsal heads. Treatment can be nonoperative or surgical. Among nonoperative procedures, alcohol injections are still commonly used as considered simple, relatively safe and well-tolerated treatment. However, they present transient and minor complications.

Methods

Two hundred patients with a diagnosis of MN underwent ultrasound-guided injections with a 47.5% alcohol solution between 2013 and 2020. We reviewed the current literature to highlight the known complications of this treatment, comparing them to the complications developed by our patients.

Results

Three patients out of 200 patients, developed necrosis of skin and subcutaneous tissue not described in previous studies about MN.

Conclusions

Our study focuses attention on the complications subsequent to the alcohol injection therapy for MN. Patients and surgeons should be aware that in a small number of cases this therapy can be burdened by necrotic complications of the skin.

Treatment of Morton's neuroma with minimally invasive distal metatarsal metaphyseal osteotomy (DMMO) and percutaneous release of the deep transverse metatarsal ligament (DTML): a case series with minimum two-year follow-up

BACKGROUND

The optimal treatment of symptomatic Morton's neuroma remains unclear; conservative methods are sometimes ineffective and neurectomy has significant rates of patient dissatisfaction. The aim of this study was to evaluate the outcome of minimally invasive distal metatarsal metaphyseal osteotomy (DMMO) and percutaneous release of the deep transverse metatarsal ligament (DTML) in patients with Morton's neuroma.

METHODS

Between January 2018 and November 2019, 27 patients (29 feet) diagnosed with Morton's neuroma after clinical and radiological evaluation underwent DMMO and percutaneous DTML release. The primary clinical outcomes were pain (VAS) and function (AOFAS score). Secondary outcomes included patient satisfaction, complications, and radiographic outcomes. Patients were followed up for a minimum of two years.

RESULTS

The median age of the participants was 66 years (range 48-79) and the follow-up time was 28 months (24-47). There was a decrease of 5.7 points in the VAS for pain (p < .001) and an increase of 19.9 in AOFAS (p < .001) after the surgical procedure. There was one case of superficial infection and one patient required resection of the neuroma (neurectomy). The majority of patients (89.7%) were satisfied and considered the procedure outcome as excellent or good.

CONCLUSION

Treatment of Morton's neuroma with minimally invasive distal metatarsal metaphyseal osteotomy and percutaneous release of the deep transverse metatarsal ligament showed significant improvement in pain and function with a low incidence of complications and a high rate of personal satisfaction.

The Management of Multiple Morton's Neuromas in the Same Foot: A Systematic Review

The optimal treatment strategy for the presentation of multiple Morton's neuromas in adjacent intermetatarsal spaces of the same foot is yet to be determined. We aimed to summarize and assess the efficacy of current treatment strategies. A systematic review, adhering to PRIMSA guidelines was performed. A computer base search was completed in PubMed, Embase, Cinahl, ISI Web of Science, Scopus and Emcare, for articles reporting the treatment of multiple neuromas in the same foot. The review is registered in the international prospective register of systematic reviews (CRD42020213631). A total of 253 articles were identified, with 7 articles being included in the review. The most common treatment strategy reported was simultaneous neuroma excision using a single incision, while 2 studies each describe simultaneous excision with 2 separate incisions and delayed excision respectively. There is no strong evidence favoring use of delayed excision or multiple incisions. Further high-quality research is required to make more definitive conclusions and future research should investigate other strategies such as non-operative treatment.

The Vulcan salute sign: a non-sensitive but specific sign for Morton's neuroma on radiographs

OBJECTIVES

To assess the value of the divergence of toes on conventional radiographs of the foot for diagnosing Morton's neuroma.

METHODS

This retrospective case-control study was approved by the local ethics committee. In 100 patients with MRI-proven Morton's neuroma 2/3 or 3/4 (study group) and 100 patients without (control group), conventional weight-bearing dorso-plantar view radiographs were evaluated for the subjective presence of interphalangeal divergence, called the Vulcan salute sign or V-sign, by two blinded, independent musculoskeletal radiologists. Interphalangeal angles (2/3 and 3/4) and intermetatarsal angle I/V were measured. The t test and chi-squared test were used to compare the groups. Diagnostic performance was calculated. Interobserver reliability was assessed using κ statistics and intraclass correlation coefficient (ICC).

RESULTS

The difference between the groups was significant (P < 0.05) regarding the presence of the V-sign, which was found in 30 of 100 patients with Morton neuroma and in 3 of 100 control patients, with a sensitivity of 30% and a specificity of 97%. The differences between interphalangeal angles were significant (P < 0.05) between the groups. The interphalangeal angle 2/3 mean values were 7.9° (± 4.8) for the study group vs 5.4° (± 2.6) for the controls; the 3/4 angle values were 6.5° (± 3.8) and 3.4° (± 2.5), respectively. There was no significant difference between the groups in the intermetatarsal angle I/V. Interobserver agreement was substantial for the V-sign, with a κ value of 0.78. The ICC was excellent concerning angle measurements, with all values ≥ 0.94.

CONCLUSION

The Vulcan salute sign on conventional radiographs is specific for Morton's neuroma.

The interphalangeal angle as a novel radiological measurement tool for Morton's neuroma - a matched case-control study

BACKGROUND

The aim of this retrospective study was to examine if a correlation between Morton's Neuroma (MN) and an increased interphalangeal angle (IPA) or intermetatarsal angle (IMA) can be found in preoperative weightbearing dorsal-plantar X-rays of the foot.

METHODS

Forty-five patients with forty-nine MN in the interspaces 2/3 or 3/4 and 49 controls were recruited for this study. Every MN was matched with an asymptomatic control without history of metatarsalgia. The diagnosis was made by clinical examination, magnetic resonance imaging (MRI) and positive histopathology after operative resection. IMA 1/5, 2/3, 2/4, 2/5, 3/4 and IPA 2/3, 3/4 were measured for both groups.

RESULTS

The IPA 3/4 was significantly enlarged by 2.8 degrees (p < 0.001) with Area under the curve (AUC) 0.75 (p < 0.001), sensitivity of 73% and specificity of 67% in feet with MN compared to controls. The IMA 3/4 was significantly enlarged by 1 degree (p < 0.048) with AUC 0.64 (p < 0.031), sensitivity of 71% and specificity of 43% in feet with MN compared to controls. No difference between IMA 2/4, 2/5, 1/5 or correlation between IPA or IMA and the size of the MN in the MRI was found.

CONCLUSION

The results confirm the clinical observation of an increased IPA in patients with MN. An increased IPA should therefore be considered in the diagnosis of MN.

Bilateral intraoral traumatic neuroma: Case report of a diagnostic challenge

Oral traumatic neuromas (TrNs) are relatively rare lesions and they originate from a damaged nerve. They present a diagnostic challenge, due to the complex clinical features that may mimic odontogenic, musculoskeletal, and other neuropathic pain conditions. We describe an interesting and challenging case of painful bilateral intraoral lesions in a 56-year-old South Indian female patient who presented with clinical features consistent with TrN lesions bilaterally, in relation to different branches of the trigeminal nerve. The patient had undergone numerous aggressive dental treatments and interventions over the past three decades, with little or no pain relief. Topical treatment with lidocaine gel utilizing a custom-made neurosensory stent rendered the patient significant and sustained pain relief.

Fascial Manipulation Technique in the Conservative Management of Morton's Syndrome: A Pilot Study

Background and Objective: Morton’s syndrome (MS) is a common cause of neuropathic chronic forefoot pain, characterised by the development of a swelling of the common digital plantar nerve, whose aetiology is not fully known. There is currently no gold standard of treatment; nonoperative management commonly involves manual therapies, orthoses therapy and infiltrative techniques, while surgery is indicated after failure of conservative measures. The present preliminary study prospectively evaluates patients affected by MS treated by Fascial Manipulation technique (FM), a noninvasive manual therapy, focused on the release of the deep fascia, reducing its stiffness. Materials and Methods: Patients with clinical and sonographic diagnosis of MS with at least a 4-month history of neuropathic symptoms underwent a cycle of three weekly FM sessions. Clinical follow-up, including VAS and AOFAS scores, was performed 21 days (T1) and 3 months (T2) after treatment. Results: Nine patients, among 28 recruited initially, completed the manual therapy sessions and relative follow-up points. This noninvasive pain treatment led to significant improvement of VAS (p = 0.0034) and AOFAS scores (p = 0.0240) at the first follow-up (T1). At 3-month follow-up (T2), both scores decreased slightly, remaining however superior to the pre-treatment values. Only VAS was still significant (p = 0.0184). Conclusions: Despite the small size of the case series, this pilot study is unique in supporting Fascial Manipulation in the nonoperative treatment of MS. Further studies are needed with a large cohort of gender balanced patients to confirm the encouraging results obtained.

Efficacy of a Single Corticosteroid Injection for Morton's Neuroma in Adults: A Systematic Review

BACKGROUND

Morton's neuroma is a common condition that routinely presents in podiatric practice. The aim of this study was to systematically synthesize the evidence relating to the effectiveness of a corticosteroid injection for Morton's neuroma.

METHODS

Studies with a publication date of 1960 or later were eligible, and searches were performed within the Turning Research Into Practice database; the Cochrane Central Register of Controlled Trials; the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register; MEDLINE (Ovid); PubMed; Embase; Cumulative Index to Nursing and Allied Health Literature; and the gray literature. Study selection criteria included randomized and nonrandomized controlled trials where a single corticosteroid injection for Morton's neuroma pain was investigated. The primary outcome was Morton's neuroma pain as measured by any standard validated pain scale.

RESULTS

Ten studies involving 695 participants were included. The quality of the studies was considered low and subject to bias. Of the included studies, five compared corticosteroid injection to usual care, one compared corticosteroid injection to local anesthetic alone, one compared ultrasound-guided to non-ultrasound-guided injections, three compared corticosteroid injections to surgery, one compared small to large neuromas, six assessed patient satisfaction, four measured adverse events, one studied return to work, and one examined failure of the corticosteroid injection to improve pain. Overall, these studies identified a moderate short- to medium-term benefit of corticosteroid injections on the primary outcome of pain and a low adverse event rate.

CONCLUSIONS

A single corticosteroid injection appears to have a beneficial short- to medium-term effect on Morton's neuroma pain. It appears superior to usual care, but its superiority to local anaesthetic alone is questionable, and it is inferior to surgical excision. A very low adverse event rate was noted throughout the studies, indicating the intervention is safe when used for Morton's neuroma. However, the quality of the evidence is low, and these findings may change with further research.

Minimally Invasive Intermetatarsal Nerve Decompression for Morton's Neuroma: A Review of 27 Cases

Minimally invasive nerve decompression for operative management of Morton's neuroma has been shown to be an effective alternative to neurectomy; however, little is known about postoperative outcomes. In this retrospective case series, we reviewed 27 procedures in 25 patients who underwent minimally invasive nerve decompression as primary surgical management for Morton's neuroma. Most subjects (22, or 88%) had 12 or more months of health plan enrollment postoperatively; 3 (12%) had 4 to 7 months of enrollment after the procedure. Postoperative patient satisfaction, complications and the need for a follow-up neurectomy were ascertained from medical record review. Additionally, demographic and clinical data were extracted from electronic sources. Patient satisfaction was unknown for 5 (18.5%) of the 27 procedures. Among the 22 (81.5%) procedures for which there were valid patient satisfaction data, patient satisfaction was excellent for 11 (50%); good for 2 (9.1%), and poor for 9 (40.9%). During the follow-up period, 5 (18.5%) patients required an open neurectomy. Among the 6 (22.2%) patients who presented without a Mulder's sign on physical exam preoperatively, 83% reported excellent results. Minimally invasive nerve decompression may not be as effective as previously seen; however, it may be indicated in patients presenting with absence of a Mulder's sign, a physically small or nascent neuroma.

Should the webspaces be a review area for Mortons neuroma on computed tomographies performed for metatarsalgia?

Purpose

Morton’s neuroma-bursal complex (MNBC) is a common cause of metatarsalgia which is usually investigated with ultrasound. Patients presenting with metatarsalgia may also have computed tomography (CT) as part of their investigation to look for alternative causes such as stress fracture. Although CT is considered to be of most use in assessing the bones in this scenario, the soft tissues can also be reviewed. This study analyses whether MNBC can reliably be detected on CT in patients presenting with metatarsalgia.

Material and methods

43 cases were identified on the Radiology Information System where both CT and ultrasound had been undertaken to assess for metatarsalgia. Two blinded consultant musculoskeletal radiologists retrospectively reviewed the CTs to determine the presence or absence of MNBC and this was compared to the ultrasound reports.

Results

There was a mean sensitivity of 45.5% and mean specificity of 62.5%. Mean accuracy was 52.3% and Youden’s index was 0.080. There was fair agreement between the two reviewers with Cohen’s κ of 0.62.

Conclusions

Sensitivity and specificity of CT for MNBC are poor. CT should not be used as an isolated modality to make a definite diagnosis regarding the presence or absence of a MNBC.

Effectiveness of corticosteroid injections in Civinini-Morton's Syndrome: A systematic review

BACKGROUND

The aim of this paper is to analyze the effectiveness of corticosteroid injections (CI), in combination with or without a local anaesthetic, for Civinini-Morton's Syndrome to determine which protocol could be the most appropriate among conservative treatments.

METHODS

All selected articles were screened using a thorough database search of PubMed, EMBASE and SCOPUS to assess their suitability to the research focus.

RESULTS

Selection produced 10 articles as full-text, for a total of 590 patients, with a mean follow-up of 14 ± 14.2 (range 3-48) months. Johnson satisfaction scale, resulting from 6 studies, scored 25.6% (range 5-38) and 39.4% (range 15-51.8), respectively completely satisfied and satisfied with minor reservations. Mean VAS, declared in 5 studies, decreased from 70.7 ± 16.5 (range 67-89) to 33.4 ± 7.6 (26-42.5) points (p < 0.01). Most common complication was skin depigmentation in 7 (2.6%) cases.

CONCLUSIONS

CI appear to be a safe treatment allowing good results with a very low complications rate. A neuroma of 6.3 mm seems to be the cut-off size; below which CI could have best indications and be considered as an intermediate treatment between shoe modifications and more invasive procedures such as percutaneous alcoholization or surgery.

LEVEL OF EVIDENCE

Level II, systematic review.

Treating Morton's neuroma by injection, neurolysis, or neurectomy: a systematic review and meta-analysis of pain and satisfaction outcomes

BACKGROUND

Individual evidence suggests that multiple modalities can be used to treat entrapment pathology by Morton's neuroma, including injection, neurolysis, and neurectomy. However, their impacts on patient pain and satisfaction have yet to be fully defined or elucidated. Correspondingly, our aim was to pool systematically identified metadata and substantiate the impact of these different modalities in treating Morton's neuroma with respect to these outcomes.

METHODS

Searches of 7 electronic databases from inception to October 2019 were conducted following PRISMA guidelines. Articles were screened against pre-specified criteria. The incidences of outcomes were extracted and pooled by random-effects meta-analysis of proportions.

RESULTS

A total of 35 articles satisfied all criteria, reporting a total of 2998 patients with Morton's neuroma managed by one of the three modalities. Incidence of complete pain relief after injection (43%; 95% CI, 23-64%) was significantly lower than neurolysis (68%; 95% CI, 51-84%) and neurectomy (74%; 95% CI, 66-82%) (P = 0.02). Incidence of complete satisfaction after injection (35%; 95% CI, 21-50%) was significantly lower than neurolysis (63%; 95% CI, 50-74%) and neurectomy (57%; 95% CI, 47-67%) (P < 0.01). The need to proceed to further surgery was significantly greater following injection (15%; 95% CI, 9-23%) versus neurolysis (2%; 95% CI, 0-4%) or neurectomy (5%; 95% CI, 3-7%) (P < 0.01). Incidence of procedural complications did not differ between modalities (P = 0.30).

CONCLUSIONS

Although all interventions demonstrated favorable procedural complication incidences, surgical interventions by either neurolysis or neurectomy appear to trend towards greater incidences of complete pain relief and complete patient satisfaction outcomes compared to injection treatment. The optimal decision-making algorithm for treatment for Morton's neuroma should incorporate these findings to better form and meet the expectations of patients.

Patient-Related Outcome Measures (PROMs) With Nonoperative and Operative Management of Morton's Neuroma

BACKGROUND

Morton's neuroma is associated with chronic pain and disability. There is a paucity of literature regarding patient-related outcome measures (PROMs) in patients managed nonoperatively. We sought to investigate nonoperative and operative management of Morton's neuroma using PROMs in patients with follow-up to 1 year.

METHODS

We conducted a prospective observational study and collected data on all patients with a new diagnosis of Morton's neuroma treated from February 2016 until April 2018. Primary outcome measures were the Manchester-Oxford Foot Questionnaire (MOXFQ) for pain, EuroQoL (EQ) time trade-off (TTO), and EQ visual analog scale (VAS) taken preoperatively and at 52 weeks postoperatively. Forty-four patients were treated nonoperatively and 94 patients were treated operatively.

RESULTS

Pretreatment and 52-week scores were 55.7 and 43.10 (nonoperative) and 63.7 and 40.1 (operative) for MOXFQ (pain), 0.72 and 0.82 (nonoperative) and 0.68 and 0.82 (operative) for EQ-TTO, and 71.5 and 76.2 (nonoperative) and 73.1 and 68.7 (operative) for EQ-VAS. There was a statistically significant improvement in MOXFQ (pain) in nonoperative (P = .02) and operative groups (P < .001). There was a statistically significant improvement in EQ-TTO in the operative group only (P = .01).

CONCLUSION

This is the largest study investigating outcomes to 12 months of both nonoperative and operatively managed patients with Morton's neuroma. Both nonoperative and operative management lead to symptom improvement at 12 months.

LEVEL OF EVIDENCE

Level III, comparative study.

An Updated Nerve Sparing Surgical Technique for Addressing Morton's Neuroma

Morton's neuroma is a common painful pathology that occurs in the plantar forefoot. Many treatment options exist and surgical management is used after conservative treatment options fail. While within the literature, there is a high success rate with primary neurectomy procedures, the risk of recurrence of symptoms or "stump neuromas" remains difficult to treat and can lead to debilitating pain. This article expands on a previously published article to discuss an update on a nerve sparing, microneurosurgical, procedure for the management of Morton's neuromas.

Morton's neuroma: review of anatomy, pathomechanism, and imaging

Morton's neuroma is a commonly encountered cause of forefoot pain, which may limit weight-bearing activities and footwear choices. Although the aetiology and pathomechanism of this condition is controversial, the histological endpoint is well established as benign perineural fibrosis of a common plantar digital nerve, typically within the third intermetatarsal space. The diagnosis of Morton's neuroma is mainly based on characteristic symptoms and clinical findings, but may be confirmed by ultrasonography. Although ultrasound is a highly accurate diagnostic tool for Morton's neuroma, it is subject to interoperator variability due to differences in technique and level of experience. In this paper, the authors review the anatomy of the common plantar digital nerves and surrounding structures in the forefoot, which are deemed relevant to the understanding of Morton's neuroma, especially from a sonographic point of view. Several theories of the pathomechanism of Morton's neuroma are briefly discussed. The main purpose of this article is to illustrate the ultrasound techniques for evaluating Morton's neuroma and performing ultrasound-guided corticosteroid injections.

ACR Appropriateness Criteria® Chronic Foot Pain

Chronic foot pain is a frequent clinical complaint, which can significantly impact the quality of live in some individuals. These guidelines define best practices with regards to requisition of imaging studies based on specific clinical scenarios, which have been grouped into different variants. Each variant is accompanied by a brief description of the usefulness, advantages, and limitations of different imaging modalities. The present narrative is the result of an exhaustive assessment of the available literature and a thorough review process by a panel of experts on Musculoskeletal Imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Ultrasound-Guided Decompression of the Intermetatarsal Nerve for Morton's Neuroma: A Novel Closed Surgical Technique

BACKGROUND

This study describes the technique for decompression of the intermetatarsal nerve in Morton's neuroma by ultrasound-guided surgical resection of the transverse intermetatarsal ligament. This technique is based on the premise that Morton's neuroma is primarily a nerve entrapment disease. As with other ultrasound-guided procedures, we believe that this technique is less traumatic, allowing earlier return to normal activity, with less patient discomfort than with traditional surgical techniques.

METHODS

We performed a pilot study on 20 cadavers to ensure that the technique was safe and effective. No neurovascular damage was observed in any of the specimens. In the second phase, ultrasound-guided release of the transverse intermetatarsal ligament was performed on 56 patients through one small (1- to 2-mm) portal using local anesthesia and outpatient surgery.

RESULTS

Of the 56 participants, 54 showed significant improvement and two did not improve, requiring further surgery (neurectomy). The postoperative wound was very small (1-2 mm). There were no cases of anesthesia of the interdigital space, and there were no infections.

CONCLUSIONS

The ultrasound-guided decompression of intermetatarsal nerve technique for Morton's neuroma by releasing the transverse intermetatarsal ligament is a safe, simple method with minimal morbidity, rapid recovery, and potential advantages over other surgical techniques. Surgical complications are minimal, but it is essential to establish a good indication because other biomechanical alterations to the foot can influence the functional outcome.

The effects of a combined physical therapy approach on Morton's Neuroma. An N-of-1 Case Report

INTRODUCTION

There is a lack of supporting evidence for conservative treatments involving Morton's Neuroma, which has often a clinical presentation with many associated complications such as functional impairment and chronic pain. This case study assessed the effects of a combined physical therapy treatment for Morton's Neuroma, an injury often referred for surgery.

METHODS

The patient suffered a long-standing Morton's Neuroma and received 6 combined physical therapy sessions that included soft-tissue massage, joint mobilization, strengthening therapeutic exercises and pain education. Values for pain with deep pressure, pain maladaptive beliefs and functionality were taken using clinical testing and questionnaires.

RESULTS

After the intervention was successfully completed, pain when applying deep pressure resolved. Functionality involving the toe-to-wall test showed an improvement in ankle dorsiflexion and better results were found in both the LEFS and FAAM questionnaires. Pain maladaptive beliefs, assessed with the Pain Catastrophizing Scale and the Pain Awareness Questionnaire also reflected an improvement.

CONCLUSION

A combined physical therapy approach shows encouraging results in the treatment of Morton's Neuroma.

A Morton's Neuroma Invading the Proper Digital Nerve

We report a case of a 55-year-old female with extreme right fourth toe pain of unknown origin that was resistant to conservative care. Resection confirmed invasion of the neuroma into the fourth digit with hypertrophy and herniation of the proper digital nerve. The patient experienced an uneventful recovery with some minor neurogenic symptoms experienced at six months postoperatively that resolved with off-loading padding and heat massage. Complete pain relief was reported at her 12-month review. Isolated neuroma within a toe results in digital pain that may respond to excision.

The effectiveness of shoe modifications and orthotics in the conservative treatment of Civinini-Morton syndrome: state of art

Civinini Morton’s Syndrome (CMS), better known as Morton’s Neuroma, is a benign enlargement that typically affects the third common digital branch of the plantar nerve. 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. Clinical symptoms, physical exam and instrumental evidence are important in assessing and grading the disease. Biomechanics seem to play an important role, especially regarding the usefulness of correct footwear. 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. (www.actabiomedica.it)

Can percutaneous alcoholization of Morton's neuroma with phenol by electrostimulation guidance be an alternative to surgical excision? Long-term results

BACKGROUND

Percutaneous alcoholization with phenol by electrostimulation guidance for the treatment of Morton's neuroma is proposed to determine a permanent chemical neurolysis.

METHODS

115 patients for 125 Morton's neuromas were treated. Ten patients were affected by multiple neuromas. Visual Analogue Scale and AOFAS score were used for the clinical assessment.

RESULTS

The mean follow-up was 8,3 years. The pre-alcoholization VAS was 85.84 ± 12.00, while at follow-up scored 28.85 ± 31.35, showing a significant decrease improving in 113/125 cases (90.4%). Treatment was considered successful with a reduction of the VAS value superior to 50% in 89 out of 125 patients (71.2%). The mean overall AOFAS score at -up was 85.09 ± 13.41.

CONCLUSIONS

Needle-electrode guided percutaneous alcoholization is an outpatient, minimally invasive procedure with low rate of complications. Better results of those obtained with traditional conservative treatments and comparable with those reported with other alcohols injections or surgical nerve excision were observed.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Intra- and Interobserver Reliability of Size Measurement of Morton Neuromas on Sonography

OBJECTIVES

Sonography is often used for analysis of Morton neuromas, but the measurement reliability is unknown. The aim of this study was to determine the intra- and interobserver reliability and precision of sonographic measurement of Morton neuromas.

METHODS

Three observers with different levels of sonography experience (observer A, expert; observer B, intermediate; observer C, beginner) performed repeated measurements of the size of Morton's neuroma in 20 patients. Intraclass correlation coefficient and limit of agreement were used to evaluate reliability and measurement precision.

RESULTS

The intraclass correlation coefficient for intraobserver reliability was 0.80, 0.71, and 0.43 (limit of agreement, 20%, 18%, and 47%) in observers A, B, and C, respectively. The intraclass correlation coefficient for interobserver reliability was 0.72, 0.38, and 0.38 (limit of agreement, 25%, 36%, and 35%) between observers A/B, A/C, and B/C, respectively.

CONCLUSIONS

The intra- and interobserver reliability values for sonographic measurement of Morton neuroma size were dependent on observer experience. Experienced observers had higher reliability, while observers who were less familiar with sonography showed moderate to low reliability.

Mechanical diagnosis and therapy and Morton's neuroma: a case-series

Objectives: Morton's neuroma (MN) is a neuralgia involving the common plantar digital nerves of the metatarsal region. Evidence-based treatment options for MN are sparse, and utility of physical therapy (PT) is unknown. Mechanical Diagnosis and Therapy (MDT) is a classification system utilizing direction-specific treatment for orthopedic conditions based on mechanical and symptomatic response to repeated end range movements. The purpose of this case series is to describe the management of three patients with a medical diagnosis of MN using the MDT classification system.Methods: Three female patients aged 54-75 years with unilateral plantar forefoot pain for 6 weeks to 8 years were referred by a podiatrist following positive clinically accepted diagnostic criteria for MN including radiological imaging and provocation testing. Patients were evaluated and treated utilizing MDT assessment and treatment principles. The intervention consisted of repeated movements matched to the patient's directional preference at either the lumbar spine (1 patient) or distal extremity (2 patients).Results: Immediate and one-year outcomes were excellent, demonstrating rapid and lasting improvement. Following discharge, the patients have been asymptomatic or able to self-manage without seeking additional medical intervention for this condition. Total visit frequency per patient averaged 2-3 visits total across 8-16 days.Discussion: Responses to repeated end range movements testing allowed for classification and prescription of exercise to rapidly improve symptoms and function in three patients referred to PT services with medically diagnosed MN. This series provides preliminary evidence that MDT may be effective in classifying and treating patients with MN.

Mechanical Diagnosis and Therapy and Morton's Neuroma: A Case Report

Purpose: Morton's neuroma (MN) is a neuralgia involving the common plantar digital nerves of the metatarsal region. Evidence-based treatment options for this condition are sparse, and physiotherapy's usefulness is limited. Client Description: A woman aged 44 years was referred to physiotherapy for left forefoot pain lasting 3 months. The podiatrist diagnosed MN using ultrasonography. Examination found positive squeeze test, painful interphalangeals and metatarsal heads, and painful metatarsophalangeal joint (MPJ) extension. Intervention: Repeated flexion of MPJ digit II relieved the patient's pain. She was treated six times over 3 months to progress treatment, achieve longer lasting pain relief, and recover function to full pain-free status, including running. Measures and Outcome: The patient's pain reduced after treatment from a variable 2-7 out of 10 on the Numeric Pain Rating Scale to 0 out of 10. After two sessions, the patient's Lower Extremity Functional Scale score improved, from 56 out of 80 to 70 out of 80, and by discharge, it was 73 out of 80. At 6-month follow-up, the patient was still running pain-free. Implications: This article describes the rapid and lasting improvement in chronic forefoot pain associated with MN after mechanical diagnosis and therapy assessment and treatment. Finding new, effective, conservative interventions is important for this condition because so few evidence-supported treatments exist. The findings from this case report demonstrate the benefit derived from exercise-based treatment and may indicate a role for physiotherapy in managing MN.

Etiology and Treatment Outcomes for Sural Neuroma

BACKGROUND

Neuroma results from disorganized regeneration following nerve injury and may be symptomatic. The aim of this study was to investigate the causes, treatment, and outcomes of operatively treated sural neuromas, and to describe the factors associated with persistent or unchanged postoperative pain symptoms.

METHODS

Consecutive patients with surgically treated sural neuromas in a 14-year period were identified using Current Procedural Terminology (CPT) codes ( n = 49), followed by a chart review to collect patient and treatment characteristics. Postoperative pain symptoms were categorized as complete resolution of pain, improvement of pain, no change in pain, or worse pain. The median patient age was 46.5 years (interquartile range [IQR], 39.1-51.3), and median follow-up was 4.0 years (IQR, 1.9-9.2).

RESULTS

Ninety percent of symptomatic sural neuromas developed as a result of previous lower extremity surgery. Initial surgery of sural neuroma led to improvement in pain in 63% of patients, and an additional 8.2% of the patients had improvement after secondary neuroma surgery. Pain relief after diagnostic injection showed a trend toward an association with postoperative pain improvement. Neuroma excision and implantation in muscle was the most common surgical technique used (67%). Four of the 7 patients that underwent a second neuroma operation reported symptom improvement.

CONCLUSION

Sural neuromas may arise from prior surgery or trauma to the lower extremity. Surgical intervention resulted in either improvement or complete resolution of pain symptoms in 71% of patients, although occasionally more than one procedure was required to obtain symptomatic relief. Preoperative anesthetic injection may help identify patients that benefit from neuroma surgery. Level of Evidence: Level IV, retrospective case series.

The effectiveness of non-surgical interventions for common plantar digital compressive neuropathy (Morton's neuroma): a systematic review and meta-analysis

BACKGROUND

Morton's neuroma (MN) is a compressive neuropathy of the common plantar digital nerve. It is a common compressive neuropathy often causing significant pain which limits footwear choices and weight bearing activities. This paper aims to review non-surgical interventions for MN, to evaluate the evidence base for the clinical management of MN.

METHODS

Electronic biomedical databases (CINAHL, EMBASE, MEDLINE and Cochrane) were searched to January 2018 for studies evaluating the effectiveness of non-surgical interventions for Morton's neuroma. Outcome measures of interest were treatment success rate (SR) (binary) and pain as measured using 100-point visual analogue scale (VAS) (continuous). Studies with and without control groups were included and were evaluated for methodological quality using the Downs and Black Quality Index. Results from randomised controlled trials (RCT) were compared between-groups, and case series were compared pre- versus post-treatment. Effect estimates are presented as odds ratios (OR) for binary data or mean differences (MD) for continuous data. Random effects models were used to pool effect estimates across studies where similar treatments were used. Heterogeneity was assessed using the I 2 statistic.

RESULTS

A total of 25 studies met the inclusion criteria, seven RCTs and 18 pre/post case series. Eight different interventions were identified, with corticosteroid or sclerosing injections being the most often reported (seven studies each). Results from a meta-analysis of two RCTs found corticosteroid injection decreased pain more than control on VAS (WMD: -5.3, 95%CI: -7.5 to - 3.2). Other RCTs reported efficacy of: manipulation/mobilisation versus control (MD: -15.3, 95%CI: -29.6 to - 1.0); extracorporeal shockwave therapy versus control (MD: -5.9, 95%CI: -21.9 to 10.1). Treatment success was assessed for extracorporeal shockwave therapy versus control (OR: 0.3, 95%CI: 0.0 to 7.1); and corticosteroid injection vs footwear/padding (OR: 6.0, 95%CI: 1.9 to 19.2). Sclerosing and Botox injections, radiofrequency ablation and cryoneurolysis have been investigated by case series studies, however these were of limited methodological quality.

CONCLUSIONS

Corticosteroid injections and manipulation/mobilisation are the two interventions with the strongest evidence for pain reduction, however high-quality evidence for a gold standard intervention was not found. Although the evidence base is expanding, further high quality RCTs are needed.

Role of imaging methods in diagnosis and treatment of Morton's neuroma

Among the many causes of forefoot pain, Morton's neuroma (MN) is often suspected, particularly in women, due to its high incidence. However, there remain controversies about its relationship with symptomatology and which diagnostic and treatment choices to choose. This article mainly focuses on the role of the various imaging methods and their abilities to support an accurate diagnosis of MN, ruling out other causes of forefoot pain, and as a way of providing targeted imaging-guided therapy for patients with MN.

Treatment of Morton's neuroma: A systematic review

BACKGROUND

The treatment of Morton's neuroma (MN) can be operative, conservative and infiltrative. Our aim was the evaluation of evidence on outcomes with different types of conservative, infiltrative and surgical treatment in patients affected by primary MN.

METHODS

The bibliographic search was conducted in MEDLINE, Cochrane Library, DARE. Only studies in English were collected. The last search was in August 2015. Case series and randomized controlled trials (RCTs) assessing patients' satisfaction or pain improvement at an average follow-up of at least 6 months after treatment of primary MN were included. Two reviewers selected the studies, evaluated their methodological quality, and retrieved data independently.

RESULTS

Of 283 titles found, only 29 met the inclusion criteria. Data showed better outcomes with operative treatment.

CONCLUSIONS

The evaluated case series and few RCTs showed better results with invasive treatment. More and better RCTs which evaluate risk-benefit ratio are required to confirm these results.

Short term comparison between blind and ultrasound guided injection in morton neuroma

OBJECTIVE

The aim of this work is to compare the effectiveness of blind and ultrasound-guided injection for Morton's neuroma (MN) to determine which is more appropriate as the initial procedure in conservative treatment.

METHODS

This is an evaluator-blinded randomised trial. Of the 56 included patients, 27 were assigned to the blind group (A) and 29 to the ultrasound-guided group (B). Injection includes 1 ml of 2% mepivacaine and 40 mg of triamcinolone in each web space with MN. The included patients were assessed clinically by VAS score and the Manchester Foot Pain and Disability Score (MFPDS). The follow-up was performed at 15 days, 1 month, 45 days, 2 months, 3 months and 6 months after the initial injection.

RESULTS

No differences in age or clinical measurements were found at presentation between group A and group B. At the follow-up, the ultrasound-guided group showed greater symptomatic relief at several stages of the follow-up: 45 days (VAS 3.0 ± 0.5 versus 5.5 ± 0.5, p = 0.001; MFPDS: 32.2 ± 1.8 versus 38.8 ± 2.0, p = 0.018), 2 months (VAS: 3.1 ± 0.5 versus 5.6 ± 0.5, p = 0.002; MFPDS: 31.5 ± 1.9 versus 38.5 ± 2.1, p = 0.020) and 3 months (VAS: 3.1 ± 0.4 versus 5.2 ± 0.6, p = 0.010; MFPDS: 31.2 ± 1.9 versus 37.7 ± 2.4, p = 0.047).

CONCLUSION

Injection of MN under ultrasound guidance provides a statistically significant improvement at some stages of the follow-up (45 days, 2 and 3 months), compared with blind injection.

KEY POINTS

• Ultrasound-guided steroid injections in Morton's neuroma provide short-term pain relief to over 60% of the patients. • Ultrasound-guided injections in Morton's neuroma lead to a higher percentage of short-term pain relief than blind injections. • Ultrasound-guided injections in Morton's neuroma lead to a lower percentage of skin side effects than blind injections.

Plantar Pressure Measurements and Geometric Analysis of Patients With and Without Morton's Neuroma

BACKGROUND

The purpose of this research was to see if there were any differences in peak pressure, contact time, pressure-time integrals, and geometric variables such as forefoot width, foot length, coefficient of spreading, and arch index between subjects with Morton's neuroma (MN) and control subjects.

METHODS

Dynamic peak plantar pressure, contact time, pressure-time integral, and geometric data were extracted using the EMED-X platform in 52 subjects with MN and 31 control subjects. Differences in peak pressure, contact time, pressure-time integral, and geometric data between participants with and those without MN were determined using independent-samples t tests. There were no significant differences in age, weight, height, and body mass index between patients with MN and control subjects.

RESULTS

There were no significant differences in the peak pressures of all masked areas and pressure-time integrals under metatarsal 2 to 4 heads between patients with MN and control subjects. In addition, no significant differences were observed between patients with MN and control subjects in geometric measurements of forefoot length, width, coefficient of spreading, foot progression angle, and arch index.

CONCLUSION

No relationship was found in this study between peak pressure, contact time, and pressure-time integral under the metatarsal heads, forefoot width, foot length, coefficient of spreading, and foot progression angle in a symptomatic MN group compared with a control group. The need to perform osteotomies to treat MN not associated with other lesser metatarsal phalangeal joint pathologies is questionable.

LEVEL OF EVIDENCE

Level III, Case-Control Study.

Sclerosing alcohol injections for the management of intermetatarsal neuromas: A systematic review

An intermetatarsal neuroma is a plantar digital neuritis causing metatarsalgia of the affected inter-metatarsal space. At present the evidence to support the management of the condition is poor with only some quality evidence supporting the short-term management of intermetatarsal neuromas using steroid injections. Some authors have supported the use of alcohol sclerosing intra-lesional injections to treat intermetatarsal neuromas. Following a search of the evidence 11 articles were identified. The systematic review found that alcohol injections appear to be safe although some papers report a short-term side effect of a flogistic reaction and there are variances in the alcohol concentration used and guiding verses not guiding the injection using ultrasound imaging. Some of the evidence may suggest a sclerosing histological effect of the nerve. However, all the studies reviewed present a research design offering a low level of evidence that is open to methodological biases and interpretation. Thus, this review found insufficient high-quality research evidence to afford conclusions on the management of intermetatarsal neuromas with alcohol sclerosing agent injections.

Clinical Utility of High-Frequency Musculoskeletal Ultrasonography in Foot and Ankle Pathology: How Ultrasound Imaging Influences Diagnosis and Management

The use of high-frequency (high-resolution) musculoskeletal ultrasonography is increasing and has shown promising utility in many areas of medicine. The utility of musculoskeletal ultrasonography for foot and ankle complaints has not been widely investigated, however. Although some conditions of the foot and ankle are easily diagnosed by physical examination, others can have nonspecific examination findings, making optimal treatment decisions difficult. We hypothesized that high-resolution musculoskeletal ultrasound scanning of the foot and ankle can affect the diagnosis and/or treatment for patients presenting with foot or ankle complaints. Retrospectively, the cases of 98 patients who had undergone musculoskeletal ultrasound scanning of the foot or ankle were reviewed. The pre-ultrasound clinical diagnosis and treatment were compared with the post-ultrasound diagnosis and treatment. In 64% of the patients, the diagnosis or treatment changed after the ultrasound examination. In 43% of patients, both the diagnosis and the treatment changed after ultrasound scanning. For those patients for whom the diagnosis and treatment were unchanged after the ultrasound examination, the ultrasound findings were concordant with the pre-ultrasound clinical diagnosis for 100% of the patients. These results suggest that in a large proportion of patients, high-resolution musculoskeletal ultrasonography of the foot or ankle can facilitate appropriate diagnosis and management.

The clinical diagnosis of symptomatic forefoot neuroma in the general population: a Delphi consensus study

BACKGROUND

There is limited evidence for defining what specific method or methods should be used to clinically influence clinical decision making for forefoot neuroma. The aim of this study was to develop a clinical assessment protocol that has agreed expert consensus for the clinical diagnosis of forefoot neuroma.

METHODS

A four-round Delphi consensus study was completed with 16 expert health professionals from either a clinical or clinical academic background, following completion of a structured literature review. Clinical experience ranged from 5 to 34 years (mean: 19.5 years). Consensus was sought on the optimal methods to achieve the clinical diagnosis of forefoot neuroma. Round 1 sought individual input with an open ended question. This developed a list of recommendations. Round 2 and 3 asked the participants to accept or reject each of the recommendations in the list in relation to the question: "What is the best way to clinically diagnose neuroma in the forefoot?" Votes that were equal to or greater than 60% were accepted into the next round; participant's votes equal to or less then 20% were excluded. The remaining participant's votes between 20 to 60% were accepted and placed into the following round for voting. Round 4 asked the participants to rank the list of recommendations according to the strength of recommendation they would give in relation to the question: "What is the best way to clinically diagnose neuroma in the forefoot?" The recruitment and Delphi rounds were conducted through email.

RESULTS

In round 1, the 16 participants identified 68 recommendations for the clinical diagnosis of forefoot neuroma. In round 2, 27 recommendations were accepted, 11 recommendations were rejected and 30 recommendations were assigned to be re-voted on. In round 3, 36 recommendations were accepted, 22 recommendations were rejected and 11 recommendations were assigned to be re-voted on. In round 4, 21 recommendations were selected by the participants to form the expert derived clinical assessment protocol for the clinical diagnosis of forefoot neuroma. From these 21 recommendations, a set of themes were established: location of pain, non weight bearing sensation, weight bearing sensation, observations, tests and imaging.

CONCLUSION

Following the identification of 21 method recommendations, a core set of clinical diagnostic methods have been prepared as a clinical assessment protocol for the diagnosis of forefoot neuroma. Based on expert opinion, the core set will assist clinicians in forming a clearer diagnosis of forefoot neuroma.

A randomized, double-blind, placebo-controlled trial of injected capsaicin for pain in Morton's neuroma

Intermetatarsal neuroma or Morton's neuroma is a painful condition of the foot resulting from an entrapment of the common digital nerve typically in the third intermetatarsal space. The pain can be severe and especially problematic with walking. Treatment options are limited and surgery may lead to permanent numbness in the toes. Capsaicin, the pungent ingredient of hot peppers, produces analgesia by inducing retraction of nociceptive afferents from the area of innervation and is effective in treating certain neuropathic pain disorders. A randomized double-blind placebo-controlled study was conducted to test the efficacy, tolerability, and safety of a single 0.1 mg dose of capsaicin vs placebo injected into the region of the neuroma. A total of 58 subjects diagnosed with Morton's neuroma with foot pain ≥4 (0-10 numerical pain rating scale) were injected with 2 mL of lidocaine into the intermetatarsal space proximal to the neuroma to provide local anesthesia. After 5 minutes, 0.1 mg capsaicin or placebo was injected into the intermetatarsal space containing the painful neuroma. Average foot pain was rated for 2 weeks before through 4 weeks after injection. At weeks 1 and 4, the decrease in pain was significantly greater in the subjects treated with capsaicin (P = 0.021 and P = 0.019, respectively). A trend toward significance was noted at weeks 2 and 3. Improvements in functional interference scores and reductions in oral analgesic use were also seen in the capsaicin-treated group. These findings suggest that injection of capsaicin is an efficacious treatment option for patients with painful intermetatarsal neuroma.

Radiographic Analysis of Feet With and Without Morton's Neuroma

BACKGROUND

The aim of this research was to investigate the association of various structural measurements of the forefoot with Morton's neuroma (MN).

METHODS

Weightbearing anteroposterior and lateral foot radiographs of subjects attending the University of Western Australia (UWA) Podiatry Clinic and the first author's private practice were included in this study. A single assessor measured the following angles: lateral intermetatarsal angle (LIMA), intermetatarsal angle (IMA), hallux valgus angle (HVA), digital divergence between the second and third digits (DD23), digital divergence between the third and fourth digits (DD34) and relative metatarsal lengths of the first to fifth metatarsals (Met1-5), and the effect of MN size as measured by ultrasonograph on digital divergence. Intratester reliability of all radiographic measurements was assessed on all radiographic measurements. The study included 101 subjects, of whom 69 were diagnosed with MN and 32 were control subjects without MN. The mean (± standard deviation) age of MN subjects was 52 (±15) years and for control subjects, 48 (±12) years.

RESULTS

When comparing all feet, there were no significant differences in the LIMA, HVA, IMA, digital divergence angles and the relative metatarsal distances between subjects with MN and control subjects. No relationship between MN size and digital divergence was found in either foot, or in either neuroma location.

CONCLUSION

We were unable to demonstrate any relationship in this study between radiographic metatarsal length and angular measurements in a symptomatic MN group compared to a control group. In addition, we did not find any correlation between the size of MN as measured from ultrasonographic images and radiographic evidence of digital divergence.

LEVEL OF EVIDENCE

Level III, case control study.

Interdigital Neuroma in the Second Intermetatarsal Space Associated with Metatarsophalangeal Joint Instability

The entrapment theory is the most commonly accepted theory concerning the development of interdigital neuroma; it incriminates the deep transverse metatarsal ligament as the major causative factor of the condition. This report presents a patient with interdigital neuroma in the second intermetatarsal space, which was strongly suspected to be caused by the metatarsophalangeal joint instability due to plantar plate injury. Surgical intervention revealed that the neuroma was located more distally and dorsally than the deep transverse metatarsal ligament and was pinched between the adjacent metatarsal heads, suggesting the involvement of the metatarsophalangeal joint instability and chronic trauma as etiologies in this case.

The relationship between foot posture index, ankle equinus, body mass index and intermetatarsal neuroma

Background

The main purpose of this study was to investigate the presence of an association between intermetatarsal neuroma and foot type, as measured by the Foot Posture Index. The study also examined whether there was a relationship between foot type and the interspace affected with intermetatarsal neuroma, and whether ankle equinus or body mass index had an effect.

Methods

In total, 100 participants were recruited from The University of Western Australia’s Podiatry Clinic, 68 of whom were diagnosed with inter-metatarsal neuroma from 2009 to 2015. There were 32 control participants recruited from 2014 to 2015. The age of subjects was recorded, as were weight and height, which were used to calculate body mass index. The foot posture index and ankle dorsiflexion were measured using standard technique. Independent t-tests and Kruskal-Wallis tests were used to compare differences in foot posture index, body mass index and ankle dorsiflexion between the inter-metatarsal neuroma and control groups. Multivariable logistic regression was also used to model relationships for outcome.

Results

The 68 intermetatarsal neuroma subjects had a mean age of 52 years (range 20 to 74 years) and comprised of 56 females and 12 males. The 32 control subjects had a mean age of 49 years (range 24 to 67 years) with 26 females and six males. There were no significant differences between the control and the intermetatarsal neuroma groups with respect to the mean foot posture index scores of the left and right foot (p = 0.21 and 0.87, respectively). Additionally no significant differences were detected between the affected intermetatarsal neuroma interspace and foot posture index (p = 0.27 and 0.47, respectively). There was no significant difference in mean body mass index between the intermetatarsal neuroma (26.9 ± 5.7) and control groups (26.5 ± 4.1) (p = 0.72). There was, however, a significant difference in mean ankle dorsiflexion between the intermetatarsal neuroma and control groups (p < 0.001 for both feet). Logistic regression models, adjusted for age, sex, foot posture index and body mass index estimated that the odds of having an intermetatarsal neuroma in the right foot increased by 61% (OR 1.61; 95% CI 1.32–1.96) with each one degree reduction of ankle dorsiflexion, and in the left foot by 43% (OR 1.43; 95% CI 1.22–1.69).

Conclusion

No relationships were found between foot posture index and body mass index with intermetatarsal neuroma, or between foot posture index and the interspaces affected. However, a strong association was demonstrated between the presence of intermetatarsal neuroma and a restriction of ankle dorsiflexion.

Skin depigmentation along lymph vessels of the lower leg following local corticosteroid injection for interdigital neuroma

Steroid injection is frequently used in the treatment of interdigital neuroma and has a high rate of success. We report the case of a patient who develops skin depigmentation at the injection site and linear streaks of depigmentation over the foot, the ankle and half way up to the knee after a steroid injection for interdigital neuroma. Minor disadvantages such as subcutaneous fat atrophy and depigmentation of the skin at the injection site are well known problems following steroid injection. Depigmentation of the skin with a lymphatic distribution in the foot after steroid injection for interdigital neuroma however, has not yet been reported before. This complication is a serious aesthetic problem and clinicians should be aware of this complication when treating patients with steroid injections for interdigital neuroma.