Diagnostic Accuracy of Clinical Tests for Morton's Neuroma Compared With Ultrasonography

Sonographic anatomy and technique to image the plantar digital nerves and aid identification of a Morton's neuroma

Introduction

The anatomy of the forefoot is complex, and the sonographic assessment to image the plantar digital nerves and exclude, diagnose or discriminate between a Morton's neuroma and intermetatarsal bursitis can be challenging.

Topic description and discussion

A good appreciation of the sonographic anatomy, technique, normal and abnormal appearances is required to undertake a sonographic assessment of the forefoot and its interspaces, particularly the plantar digital nerves. This is unpacked in this paper with associated pictorial aids. Muscles, tendons, and ligaments of the interspaces and the nearby metatarsophalangeal joints and their associated soft-tissue structures are helpful sonographic landmarks to guide imaging and assessment of the common and proper plantar digital nerves and the intermetatarsal bursa. These need to be appreciated from both dorsal and plantar sonographic approaches, in both short- and long-axis imaging planes.

Conclusion

Improved understanding of the anatomy and sonographic appearances of the interspace structures can enhance the sonographic assessment of the forefoot and improve diagnosis of a Morton's neuroma and/or intermetatarsal bursitis when present to guide patient management.

Treatments for Morton's neuroma

BACKGROUND

Morton's neuroma (MN) is a painful neuropathy resulting from a benign enlargement of the common plantar digital nerve that occurs commonly in the third webspace and, less often, in the second webspace of the foot. Symptoms include burning or shooting pain in the webspace that extends to the toes, or the sensation of walking on a pebble. These impact on weight-bearing activities and quality of life.

OBJECTIVES

To assess the benefits and harms of interventions for MN.

SEARCH METHODS

On 11 July 2022, we searched CENTRAL, CINAHL Plus EBSCOhost, ClinicalTrials.gov, Cochrane Neuromuscular Specialised Register, Embase Ovid, MEDLINE Ovid, and WHO ICTRP. We checked the bibliographies of identified randomised trials and systematic reviews and contacted trial authors as needed.

SELECTION CRITERIA

We included all randomised, parallel-group trials (RCTs) of any intervention compared with placebo, control, or another intervention for MN. We included trials where allocation occurred at the level of the individual or the foot (clustered data). We included trials that confirmed MN through symptoms, a clinical test, and an ultrasound scan (USS) or magnetic resonance imaging (MRI).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We assessed bias using Cochrane's risk of bias 2 tool (RoB 2) and assessed the certainty of the evidence using the GRADE framework.

MAIN RESULTS

We included six RCTs involving 373 participants with MN. We judged risk of bias as having 'some concerns' across most outcomes. No studies had a low risk of bias across all domains. Post-intervention time points reported were: three months to less than 12 months from baseline (nonsurgical outcomes), and 12 months or longer from baseline (surgical outcomes). The primary outcome was pain, and secondary outcomes were function, satisfaction or health-related quality of life (HRQoL), and adverse events (AE). Nonsurgical treatments Corticosteroid and local anaesthetic injection (CS+LA) versus local anaesthetic injection (LA) Two RCTs compared CS+LA versus LA. At three to six months: • CS+LA may result in little to no difference in pain (mean difference (MD) -6.31 mm, 95% confidence interval (CI) -14.23 to 1.61; P = 0.12, I2 = 0%; 2 studies, 157 participants; low-certainty evidence). (Assessed via a pain visual analogue scale (VAS; 0 to 100 mm); a lower score indicated less pain.) • CS+LA may result in little to no difference in function when compared with LA (standardised mean difference (SMD) -0.30, 95% CI -0.61 to 0.02; P = 0.06, I2 = 0%; 2 studies, 157 participants; low-certainty evidence). (Function was measured using: the American Orthopaedic Foot and Ankle Society Lesser Toe Metatarsophalangeal-lnterphalangeal Scale (AOFAS; 0 to 100 points) - we transformed the scale so that a lower score indicated improved function - and the Manchester Foot Pain and Disability Schedule (MFPDS; 0 to 100 points), where a lower score indicated improved function.) • CS+LA probably results in little to no difference in HRQoL when compared to LA (MD 0.07, 95% CI -0.03 to 0.17; P = 0.19; 1 study, 122 participants; moderate-certainty evidence), and CS+LA may not increase satisfaction (risk ratio (RR) 1.08, 95% CI 0.63 to 1.85; P = 0.78; 1 study, 35 participants; low-certainty evidence). (Assessed using the EuroQol five dimension instrument (EQ-5D; 0-1 point); a higher score indicated improved HRQoL.) • The evidence is very uncertain about the effects of CS+LA on AE when compared with LA (RR 9.84, 95% CI 1.28 to 75.56; P = 0.03, I2 = 0%; 2 studies, 157 participants; very low-certainty evidence). Adverse events for CS+LA included mild skin atrophy (3.9%), hypopigmentation of the skin (3.9%) and plantar fat pad atrophy (2.6%); no adverse events were observed with LA. Ultrasound-guided (UG) CS+LA versus non-ultrasound-guided (NUG) CS+LA Two RCTs compared UG CS+LA versus NUG CS+LA. At six months: • UG CS+LA probably reduces pain when compared with NUG CS+LA (MD -15.01 mm, 95% CI -27.88 to -2.14; P = 0.02, I2 = 0%; 2 studies, 116 feet; moderate-certainty evidence). (Assessed with a pain VAS.) • UG CS+LA probably increases function when compared with NUG CS+LA (SMD -0.47, 95% CI -0.84 to -0.10; P = 0.01, I2 = 0%; 2 studies, 116 feet; moderate-certainty evidence). We do not know of any established minimum clinical important difference (MCID) for the scales that assessed function, specifically, the MFPDS and the Manchester-Oxford Foot Questionnaire (MOXFQ; 0 to 100 points; a lower score indicated improved function.) • UG CS+LA may increase satisfaction compared with NUG CS+LA (risk ratio (RR) 1.71, 95% CI 1.19 to 2.44; P = 0.003, I2 = 15%; 2 studies, 114 feet; low-certainty evidence). • HRQoL was not measured. • UG CS+LA may result in little to no difference in AE when compared with NUG CS+LA (RR 0.42, 95% CI 0.12 to 1.39; P = 0.15, I2 = 0%; 2 studies, 116 feet; low-certainty evidence). AE included depigmentation or fat atrophy for UG CS+LA (4.9%) and NUG CS+LA (12.7%). Surgical treatments Plantar incision neurectomy (PN) versus dorsal incision neurectomy (DN) One study compared PN versus DN. At 34 months (mean; range 28 to 42 months), PN may result in little to no difference for satisfaction (RR 1.06, 95% CI 0.87 to 1.28; P = 0.58; 1 study, 73 participants; low-certainty evidence), or for AE (RR 0.95, 95% CI 0.32 to 2.85; P = 0.93; 1 study, 75 participants; low-certainty evidence) compared with DN. AE for PN included hypertrophic scaring (11.4%), foreign body reaction (2.9%); AE for DN included missed nerve (2.5%), artery resected (2.5%), wound infection (2.5%), postoperative dehiscence (2.5%), deep vein thrombosis (2.5%) and reoperation with plantar incision due to intolerable pain (5%). The data reported for pain and function were not suitable for analysis. HRQoL was not measured.

AUTHORS' CONCLUSIONS

Although there are many interventions for MN, few have been assessed in RCTs. There is low-certainty evidence that CS+LA may result in little to no difference in pain or function, and moderate-certainty evidence that UG CS+LA probably reduces pain and increases function for people with MN. Future trials should improve methodology to increase certainty of the evidence, and use optimal sample sizes to decrease imprecision.

Common Painful Foot and Ankle Conditions: A Review

Importance

Morton neuroma, plantar fasciitis, and Achilles tendinopathy are foot and ankle conditions that are associated with pain and disability, but they can respond to nonoperative treatment.

Observations

Morton neuroma, consisting of interdigital neuronal thickening and fibrosis, is characterized by burning pain in the ball of the foot and numbness or burning pain that may radiate to the affected toes (commonly the third and fourth toes). First-line nonoperative therapy consists of reducing activities that cause pain, orthotics, and interdigital corticosteroid injection; however, approximately 30% of patients may not respond to conservative treatment. Plantar fasciitis accounts for more than 1 million patient visits per year in the US and typically presents with plantar heel pain. Fifteen years after diagnosis, approximately 44% of patients continue to have pain. First-line nonoperative therapy includes stretching of the plantar fascia and foot orthotics, followed by extracorporeal shockwave therapy, corticosteroid injection, or platelet-rich plasma injection. Midportion Achilles tendinopathy presents with pain approximately 2 to 6 cm proximal to the Achilles insertion on the heel. The primary nonoperative treatment involves eccentric strengthening exercises, but extracorporeal shockwave therapy may be used.

Conclusions and Relevance

Morton neuroma, plantar fasciitis, and Achilles tendinopathy are painful foot and ankle conditions. First-line therapies are activity restriction, orthotics, and corticosteroid injection for Morton neuroma; stretching and foot orthotics for plantar fasciitis; and eccentric strengthening exercises for Achilles tendinopathy.

Longitudinal Plantar Approach for Excision of Morton's Neuroma: Long-Term Results

Longitudinal plantar approaches are generally considered at risk for wound healing problems. Thus, we wanted to investigate long-term outcomes after a primary Morton's neuroma excision through a longitudinal plantar approach. A retrospective study of patients with primary neuroma excision was conducted. Twenty-four patients (28 feet) were evaluated at a mean 9-year follow-up (range, 6-14) by a single trained examiner using a specific postoperative evaluation protocol, including AOFAS Forefoot subjective and objective scores. Good-to-excellent outcomes were reported in 25 (89.3%) cases. A hypertrophic scar formation and keratosis occurred in only 2 cases (7.1%). All the patients, with a single exception, achieved full weightbearing with a postoperative shoe from the first day after the operation. A longitudinal plantar approach can lead to long-term, good-to-excellent outcomes with no case of recurrence or reoperation. Accurate wound closure and immediate weightbearing with a postoperative shoe can minimize the rate of complications. This approach should be considered for primary resection of Morton's neuromas.

Long-term comparison between blind and ultrasound-guided corticoid injections in Morton neuroma

OBJECTIVES

This work compares the effectiveness of blind versus ultrasound (US)-guided injections for Morton neuroma (MN) up to 3 years of follow-up.

METHODS

This is an evaluator-blinded randomised trial in which 33 patients with MN were injected by an experienced orthopaedic surgeon based on anatomical landmarks (blind injection, group 1) and 38 patients were injected by an experienced musculoskeletal radiologist under US guidance (group 2). Patients were assessed using the visual analogue scale and the Manchester Foot Pain and Disability index (MFPDI). Injections consisted of 1 ml of 2% mepivacaine and 40 mg triamcinolone acetonide in each web space with MN. Up to 4 injections were allowed during the first 3 months of follow-up. Follow-up was performed by phone calls and/or scheduled consultations at 15 days, 1 month, 45 days, 2 months, 3 months, 6 months and 1, 2 and 3 years. Statistical analysis was performed using unpaired Student's t tests.

RESULTS

No differences in age or clinical measures were found at presentation between group 1 (VAS, 8.5 ± 0.2; MFPDI, 40.9 ± 1.1) and group 2 (VAS, 8.4 ± 0.2; MFPDI, 39.8 ± 1.2). Improvement in VAS was superior in group 2 up to 3 years of follow-up (p < 0.05). Improvement in MFPDI was superior in group 2 from 45 days to 2 years of follow-up (p < 0.05). Satisfaction with the treatment was higher in group 2 (87%) versus group 1 (59.1%) at 3 years of follow-up.

CONCLUSION

Ultrasound-guided injections lead to a greater percentage of long-term improvement than blind injections in MN.

KEY POINTS

• Ultrasound-guided corticosteroid injections in Morton neuroma provide long-term pain relief in more than 75% of patients. • Ultrasound-guided injections in Morton neuroma led to greater long-term pain relief and less disability than blind injections up to 3 years of follow-up. • The presence of an ipsilateral neuroma is associated with worse long-term disability score.

Long-term results of dorsal neuroma/nerve transposition in the surgical management of Morton's neuroma and correlation with intraoperative anatomical variations

Background

Morton's neuroma (MN) is a common cause of forefoot pain. After failure of conservative management, surgical procedures include neurectomy or neuroma preserving procedures; resection of deep transverse intermetatarsal ligament only (DTIML), dorsal neurolysis, dorsal nerve transposition (DNT).

Objectives

This retrospective study evaluates the long-term results of open DNT, and it also reports anatomical variants in the plantar interdigital nerve.

Material and methods

The study included 39 patients (30 females and 9 males) who were treated for MN between 2002 and 2016.

Results

The mean pre-operative Giannini score of 13 (0–30) improved to 61 (20–80) (p < .0001), with only 6 patients scoring less than 50 (poor). Using Coughlin’s criterion for overall satisfaction, 9 patients (23%) reported excellent, 18 patients (46%) good, 6 patients (15%) fair and 6 patients (15%) reported poor results. In the long term, 25 patients (64%) had no pain, 8 patients (20%) had mild pain, and 6 patients (16%) had severe pain. Ten patients (26%) reported normal sensitivity in their toes, 26 patients (66%) had numbness, and 3 patients (8%) reported dysesthesia in their toes. Twenty-two patients (56%) could wear fashionable shoes, 11 patients (28%) comfortable shoes, and 6 patients (16%) modified shoes. Regarding walking distance, 30 patients (77%) had no limitation, and 9 patients (23%) reported some limitation. Nineteen per cent regretted having surgery. Around 40% (17 out of 43 web spaces) showed anatomical variations in either the nerve or in the web space and we could not identify any specific risk factors in relation to the outcome.

Conclusion

Dividing the DTIML or dorsal neurolysis should be considered as the primary surgical treatment and, if this fails, neurectomy would be an option. DNT can be considered if one is concerned about stump neuroma, but this may be technically demanding and in some patients it may not be possible.

Level of Evidence: Level IV - Case Control Retrospective study.

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.

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.

Ultrasound-guided treatment of Morton's neuroma

Morton’s neuroma is a painful lesion of the interdigital nerve, usually at the third intermetatarsal space, associated with fibrotic changes in the nerve, microvascular degeneration, and deregulation of sympathetic innervation. Patients usually present with burning or sharp metatarsalgia at the dorsal or plantar aspect of the foot. The management of Morton’s neuroma starts with conservative measures, usually with limited efficacy, including orthotics and anti-inflammatory medication. When conservative treatment fails, a series of minimally invasive ultrasound-guided procedures can be employed as second-line treatments prior to surgery. Such procedures include infiltration of the area with a corticosteroid and local anesthetic, chemical neurolysis with alcohol or radiofrequency thermal neurolysis. Ultrasound aids in the accurate diagnosis of Morton’s neuroma and guides the aforementioned treatment, so that significant and potentially long-lasting pain reduction can be achieved. In cases of initial treatment failure, the procedure can be repeated, usually leading to the complete remission of symptoms. Current data shows that minimally invasive treatments can significantly reduce the need for subsequent surgery in patients with persistent Morton’s neuroma unresponsive to conservative measures. The purpose of this review is to present current data on the application of ultrasound for the diagnosis and treatment of Morton’s neuroma, with emphasis on the outcomes of ultrasound-guided treatments.

Common Complaints of the Hands and Feet

Primary care providers frequently care for complaints of the hands and feet. Here, the author describes the typical presentations of hand osteoarthritis, carpal tunnel syndrome, ganglion cysts, plantar fasciitis, onychomycosis, and Morton neuroma. Useful physical examination techniques are described. The history and physical examination are usually sufficient to diagnose these conditions without the need for more advanced testing. All of these conditions have evidence-based therapy that can be initiated by the primary care provider. These treatments as well as reasons to refer to a specialist are reviewed.

Relationship Between Sensory Symptoms, Mulder's Sign, and Dynamic Ultrasonographic Findings in Morton's Neuroma

BACKGROUND

Morton's neuroma (MN) is often a diagnostic dilemma lacking a gold standard set of diagnostic criteria. Advanced imaging of MN is evolving including ultrasonography. The current study aimed to analyze the relationship between ultrasonographic findings and symptoms, clinical data, and operative findings in a subgroup of patients.

METHODS

We evaluated physical examination, ultrasonographic findings, symptoms, and in a subgroup, the operative findings for Morton's neuroma. We analyzed the symptoms, the findings on physical examination, and ultrasonography data and performed a statistical correlation between them. A total of 175 patients were seen for suspected Morton's neuroma during the last 7 years.

RESULTS

Neuropathic pain of the toes was reported in 63% of patients. Presence of ultrasonographic findings suggesting Morton's neuroma was observed in 77% of cases. A mild significant relationship between neuropathic pain and positive ultrasonographic findings was observed. We found a strong correlation between ultrasonographic and clinical evaluation, but more than half with clinical negative Morton's neuroma had positive findings at ultrasonography. In the subgroup of operatively treated patients (n = 44) surgery confirmed Morton's neuroma in all patients who had positive ultrasonography findings.

CONCLUSIONS

The current study suggests that the association of ultrasonographic evaluation and clinical evaluation can be very useful for the management of Morton's neuroma. Our study could help with the development of a multiperspective approach in the diagnosis of Morton's neuroma.

LEVEL OF EVIDENCE

Level II, prospective cohort survey study.

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.

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.

Sex Correlation to the Prevalence of Pedal Neuromas in Various Interspaces: A Retrospective Study

BACKGROUND

Morton's neuromas are abnormalities of the common digital nerve branch located between the lesser metatarsal heads. Historically, interdigital (Morton's) neuromas have been characterized as being most common in the third interspace and in females. The principal investigator observed Morton's neuromas commonly in the second and third interspaces in both sexes. To our knowledge, no literature exists to evaluate Morton's neuroma location with a focus on each sex independently. The present study evaluates Morton's neuroma interspace location and whether there is a variation by sex.

METHODS

In this retrospective study, 582 deidentified magnetic resonance imaging reports with a diagnosis code for Morton's neuroma were evaluated for patients scanned from January 2, 2015, through April 19, 2016. Incomplete records and those with radiologist findings inconsistent with Morton's neuroma were eliminated. For the remaining 379 patients, data were collected on sex, laterality, history of trauma, plantar plate tear, age, and interspace location. Special focus was given to second and third interspace Morton's neuromas. Data were evaluated using the Pearson χ2 and independent-samples Mann-Whitney U tests, with P < .05 indicating statistical significance.

RESULTS

No statistically significant distribution between sex and second and third interspace Morton's neuromas was noted. Right vs left foot, age, and history of trauma did not vary statistically significantly between sexes. There was a statistically significant difference between the presence of plantar plate tears between sexes. Male patients with Morton's neuromas were found to have a higher rate of plantar plate tears (P = .01).

CONCLUSIONS

This study found that there were no statistically significant differences between sexes and Morton's neuromas location, laterality, or age.

Five Centimeters Morton's Neuroma in a 46-Year-Old Woman Affected by Macrodactily

The present article described the case of a voluminous Morton's neuroma of the third intermetatarsal space in a patient affected by macrodactily. The case was unique because of its dimensions, the uncommon surgical approach which was needed for removal, the association with macrodactily of the fourth toe with Raynaud's phenomenon, and the postoperative defect in the intrinsic muscles. The patient was operated in February 2016 by transverse plantar approach. Twelve months after surgery, the patient complained for hypoesthesia on third and fourth toes with inability to actively spread the toes and enlargement in the second interdigital space. The dimensions of the lesions may be explained with the presence of macrodactily in the fourth toe with occasional Raynaud's phenomenon, which may have caused an abnormal arrangement of the nerve branches for the fourth interspace with related microtrauma. A plantar approach was highly recommended as the size of the lesion forced it to the plantar surface of the foot. The inability to actively spread the toes and the enlargement of the second interdigital space are likely to be related to a deficiency of the interosseous muscles, innervated by the deep branch of the lateral plantar nerve, which had probably been sacrificed because of the size of the lesion and the subversion of the surrounding anatomical relationships.

Morton's neuroma - Current concepts review

Morton's neuroma is a common pathology affecting the forefoot. It is not a true neuroma but is fibrosis of the nerve. This is caused secondary to pressure or repetitive irritation leading to thickness of the digital nerve, located in the third or second intermetatarsal space. The treatment options are: orthotics, steroid injections and surgical excision usually performed through dorsal approach. Careful clinical examination, patient selection, pre-operative counselling and surgical technique are the key to success in the management of this condition.

Scientific Evidence in the Treatment of Metatarsalgia

Metatarsalgia is a common foot disease with a multitude of causes. Proper identification of underlying diseases is mandatory to formulate an adequate treatment. Multiple surgical solutions are available to treat metatarsalgia. Only limited scientific evidence is available in the literature. However, most of the techniques used in the treatment of metatarsalgia seem to be reasonable with acceptable results.

Value of Preoperative Imaging and Intraoperative Histopathology in Morton's Neuroma

BACKGROUND

Recent studies have demonstrated that clinical diagnosis of Morton's neuroma is highly correlated with operative and histopathologic diagnosis, whereas others have questioned the cost-effectiveness of intraoperative histopathology of excised specimens. The purpose of this study was to determine the utility of both preoperative imaging and intraoperative histology in the treatment of Morton's neuroma in making an accurate diagnosis, guiding treatment decisions, and altering clinical outcomes.

METHODS

A retrospective review was performed on all patients who underwent operative resection suspected Morton's neuroma with 4 fellowship-trained foot and ankle surgeons between 2007 and 2017. Procedures were excluded from the study if the pathology report was not available for review. Diagnoses were made either by clinical examination and/or by the results of preoperative imaging. All pathology reports were reviewed to determine the final diagnosis, considered the "gold standard." Postoperative chart notes were reviewed to determine if any treatment regimen was altered based on the pathology report revealing an alternate diagnosis other than Morton's neuroma. Two hundred eighty-seven procedures in 269 patients with 313 clinically suspected neuromas met inclusion criteria.

RESULTS

Of the 313 suspected neuromas, 309 (98.7%) were confirmed Morton's neuromas on histopathologic examination. For no patient did the results of the pathology report alter the postoperative treatment course. Preoperative imaging results were available for 179 (57.2%) suspected neuromas, with magnetic resonance imaging (MRI) and ultrasonography used to preoperatively image 121 and 71 suspected neuromas, respectively, including 13 using both. The total estimated cost of histopathologic analysis for the cohort was $143 667, and the estimated combined cost of preoperative imaging and intraoperative histopathology in our cohort totaled $278 567.

CONCLUSION

Our study found that the diagnosis of Morton's neuroma could be made clinically with extreme accuracy and positive predictive value, calling into question the utility and costs of other imaging modalities and intraoperative sampling for histopathologic diagnosis.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

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.

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.

Mechanical Metatarsalgia as a Risk Factor for Relapse of Morton's Neuroma After Ultrasound-Guided Alcohol Injection

Although many treatment modalities are available for Morton's neuroma, the injection of the neuroma with alcohol has gained popularity. However, recently, some investigators have observed a progressive deterioration in pain scores for patients initially pain free after the treatment. The purpose of the present retrospective comparative study was to determine whether mechanical metatarsalgia is related to symptom recurrence. We included 104 consecutive cases of ultrasound-guided alcohol injection for Morton's neuroma in 92 patients. Of these 104 cases, 51 were in group A (49%; Morton's neuroma) and 53 in group B (51%; Morton's neuroma associated with mechanical metatarsalgia). We evaluated each patient using a visual analog scale and American Orthopaedic Foot and Ankle Society forefoot scale, and Johnson satisfaction scale, with a mean follow-up period of 24 (range 12 to 39) months. Concomitant functional and mechanical disorders have been identified and treated with orthopedic inserts. The present study compared the clinical results and recurrence of symptoms in patients with isolated Morton's disease or Morton's disease associated with mechanical metatarsalgia. Of the 104 cases, the patients for 93 cases (89%) were completely satisfied or satisfied with minor reservations. No major complications developed. Symptoms recurred in 6 patients (6%), in whom neuroma was associated with mechanical disorders (p = .0269). Ultrasound-guided alcohol injection of Morton's neuroma is a relatively safe and well-tolerated treatment. Symptom recurrence is often associated with mechanical metatarsalgia. The treatment of the concomitant anatomical and functional disorders that target the genesis of the neuroma has an important role in the prevention of recurrence of this pathology.

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.

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.

Morton's interdigital neuroma of the foot: A literature review

Morton's neuroma is one of the most common causes of metatarsalgia. Despite this, it remains little studied, as the diagnosis is clinical with no reliable instrumental diagnostics, and each study may deal with incorrect diagnosis or inappropriate treatment, which are difficult to verify. The present literature review crosses all key points, from diagnosis to surgical and nonoperative treatment, and recurrences. Nonoperative treatment is successful in a limited percentage of cases, but it can be adequate in those who want to delay or avoid surgery. Dorsal or plantar approaches were described for surgical treatment, both with strengths and weaknesses that will be scanned. Failures are related to wrong diagnosis, wrong interspace, failure to divide the transverse metatarsal ligament, too distal resection of common plantar digital nerve, an association of tarsal tunnel syndrome and incomplete removal. A deep knowledge of the causes and presentation of failures is needed to surgically face recurrences.

Is Histopathological Analysis of Interdigital Morton's Neuroma Necessary?

BACKGROUND

Interdigital neuroma (IN), otherwise known as Morton's neuroma, is a common cause of metatarsalgia presenting to the elective foot and ankle clinic. Surgical excision of the IN in patients who fail to respond to nonoperative measures is considered to be the gold standard of care in many centers. The Royal College of Pathologists UK recommend that all excised interdigital Morton's neuromas are sent for formal histopathological analysis. We present a study correlating clinical and radiological diagnosis with histopathologic appearances of IN following surgical excision, and question if routine histopathological analysis is warranted.

METHODS

A retrospective study was carried out in a single center. Ninety-six operative records were reviewed to identify all the cases of IN surgically resected between January 2007 and July 2016. The histopathology result of the resected IN specimen, that had a clinical and radiological diagnosis of IN, was analyzed.

RESULTS

A total of 85 patients met the inclusion criteria and were included in the final analysis. We found that 100% of patients with a clinical, radiographic, and intraoperative diagnosis of a Morton's neuroma had a histopathological report confirming a Morton's interdigital neuroma.

CONCLUSION

In our single-surgeon series, histopathologic diagnosis is in complete agreement with clinical and radiological diagnosis. We therefore recommend that routine histopathological analysis of IN is not necessary, saving resources and providing a cost benefit. Histopathologic examination should be reserved only in cases where intraoperative findings do not concur with clinical and radiological features.

LEVELS OF EVIDENCE

Level IV: Case series.

Ultrasound Evaluation of Morton Neuroma Before and After Laser Therapy

OBJECTIVE

The objective of our study was to retrospectively assess for differences in imaging appearances of Morton neuromas before and after laser therapy using diagnostic ultrasound (US).

MATERIALS AND METHODS

A retrospective review was performed to identify patients who underwent US imaging to evaluate for Morton neuroma during the study period (June 1, 2013-July 1, 2014); of the 42 patients identified, 21 underwent US evaluations before and after laser therapy. US reports and images were reviewed and correlated with clinical history. The final study group consisted of 21 patients who had a total of 31 Morton neuromas evaluated using US after treatment. A retrospective review was then performed to characterize the appearances of these lesions before and after therapy followed by an analysis of variables.

RESULTS

Retrospective US review of 31 pretreatment Morton neuromas showed fusiform, heterogeneously hypoechoic masses with well-defined borders in most cases and that pain was reported when transducer pressure was applied in 97% (30/31) of cases. After treatment, lesions showed ill-defined borders (23/31), and pain with application of transducer pressure was either significantly decreased or absent (29/31); these findings were concordant with the clinical findings. Both of these characteristics were statistically significant (p < 0.0001). In addition, more Morton neuromas occurred in the second intermetatarsal space than in the third intermetatarsal space (p < 0.0001).

CONCLUSION

US may be used to identify posttreatment changes after laser therapy of Morton neuromas. Posttreatment changes include ill-defined borders and less pain or the absence of pain with the application of transducer pressure. These criteria may be applied in future clinical studies evaluating the efficacy of laser therapy for Morton neuroma.

Corticosteroid injection for Morton's neuroma with or without ultrasound guidance: a randomised controlled trial

AIMS

The objective of this double-blind randomised controlled trial was to assess whether ultrasound guidance improved the efficacy of corticosteroid injections for Morton's neuroma (MN).

PATIENTS AND METHODS

In all, 50 feet (40 patients) were recruited for this study but five feet were excluded due to the patients declining further participation. The mean age of the remaining 36 patients (45 feet) was 57.8 years (standard deviation (sd) 12.9) with a female preponderance (33F:12M). All patients were followed-up for 12 months. Treatment was randomised to an ultrasound guided (Group A) or non-ultrasound guided (Group B) injection of 40 mg triamcinolone acetonide and 2 ml 1% lignocaine, following ultrasound confirmation of the diagnosis.

RESULTS

The mean visual analogue score for pain improved significantly in both groups (Group A - from 64 mm, sd 25 mm to 29 mm, sd 27; Group B - from 69 mm, sd 23 mm to 37 mm, sd 25) with no statistical difference between them at all time-points. The failure rate within 12 months of treatment was 11/23 (48%) and 12/22 (55%) in Groups A and B, respectively (p = 0.458). The improvement in Manchester Oxford Foot Questionnaire Index and patient satisfaction favoured Group A in the short-term (three months) that almost reached statistical significance (p = 0.059 and 0.066 respectively). However, this difference was not observed beyond three months.

CONCLUSION

This study has shown that ultrasound guidance did not demonstrably improve the efficacy of corticosteroid injections in patients with MN.

TAKE HOME MESSAGE

In the presence of a clear diagnosis of MN, a trained clinician who understands the forefoot anatomy may perform an injection without ultrasound guidance with good and safe results.

Percutaneous Image-Guided Musculoskeletal Tumor Treatments

OBJECTIVE

The purpose of this article is to review the current guidelines and recommendations for percutaneous image-guided treatment of musculoskeletal tumors.

CONCLUSION

With the ongoing technologic advances, it is essential that the musculoskeletal interventionalist is familiar with the current tools and techniques available for the treatment of soft-tissue and bone tumors. Fortunately, many of these tools are readily available in a standard interventional radiology department and can be easily applied to the musculoskeletal system.

Correlation of Clinical, Operative, and Histopathologic Diagnosis of Interdigital Neuroma and the Cost of Routine Diagnosis

BACKGROUND

Diagnosis of an interdigital neuroma (IDN) is clinically based on patient symptoms. During operative excision, it is common to send the excised specimen for routine histopathologic examination. The purpose of this study was to evaluate the accuracy of the clinical and intraoperative diagnosis of IDN and correlate these with the histopathologic results of IDN.

METHODS

Case logs of 3 fellowship-trained foot and ankle surgeons were reviewed to identify all neuroma excisions completed between 1997 and 2014. Charts were reviewed to identify the preoperative clinical diagnosis and intraoperative diagnosis as well as concern for pathology besides a neuroma. All results were compared to final histopathology to identify instances of discordance between diagnoses. A total of 123 patients with 133 neuromas were identified.

RESULTS

Of the total 133 neuromas, 5 cases included a clinical or intraoperative concern for a diagnosis other than neuroma. In these 5 instances surgeons accurately identified cysts and rheumatoid nodules. 132 of 133 histopathology reports indicated the presence of nerve tissue in their report. There were no reports of malignancy or abnormal nerve tissue. There were no changes to the postoperative protocol based on histopathology.

CONCLUSION

The clinical, intraoperative, and histopathologic diagnosis of neuroma was in concordance 100% of the time. With a high level of clinical and intraoperative acumen in identifying a neuroma, we believe it is reasonable not to submit the specimen for histopathologic evaluation. In addition, limiting the amount of routine histopathologic evaluation could have saved approximately $480 per case.

LEVEL OF EVIDENCE

Level IV, case series.

Ultrasound-guided intervention in the ankle and foot

In this comprehensive review, we discuss the main interventions performed in the foot and ankle for Achilles tendinopathy, Morton's neuromas and Plantar fasciitis as well as techniques for intra-articular and peritendinous injections. We present the different imaging techniques and injectable agents that can be used in clinical practice, trying to help the reader decide the most appropriate way of managing the patient with a problem in the ankle and foot.