The role of MRI and ultrasound imaging in Morton’s neuroma and the effect of size of lesion on symptoms

The role of high-resolution ultrasound and MRI in the evaluation of peripheral nerves in the lower extremity

Lower extremity peripheral neuropathy is a commonly encountered neurologic disorder, which can lead to chronic pain, functional disability, and decreased quality of life for a patient. As diagnostic imaging modalities have improved, imaging has started to play an integral role in the detection and characterization of peripheral nerve abnormalities by non-invasively and accurately identifying abnormal nerves as well as potential causes of neuropathy, which ultimately leads to precise and timely treatment. Ultrasound, which has high spatial resolution and can quickly and comfortably characterize peripheral nerves in real time along with associated denervation muscle atrophy, and magnetic resonance neurography, which provides excellent contrast resolution between nerves and other tissues and between pathologic and normal segments of peripheral nerves, in addition to assessing reversible and irreversible muscle denervation changes, are the two mainstay imaging modalities used in peripheral nerve assessment. These two modalities are complimentary, and one may be more useful than the other depending on the nerve and location of pathology. Imaging must be interpreted in the context of available clinical information and other diagnostic studies, such as electrodiagnostic tests. Here, we offer a comprehensive overview of the role of high-resolution ultrasound and magnetic resonance neurography in the evaluation of the peripheral nerves of the lower extremity and their associated neuropathies.

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.

Plantar and dorsal approaches for excision of morton's neuroma: a comparison study

Background

Morton’s neuroma is a painful enlargement of the plantar digital nerve between the metatarsal heads that causes pain of the forefoot. Several approaches have been used to treat Morton’s neuroma, each of them having distinct advantages and disadvantages.

Objectives

The purpose of this study was to investigate and compare the clinical outcomes of neurectomy in the treatment of Morton’s neuroma through plantar and dorsal approaches.

Materials and methods

A total of 20 patients with a mean age of 48.5 ± 13.0 years (range: 19–66 years) who underwent excision of a Morton’s neuroma that did not respond to conservative treatment were retrospectively analysed from June 2014 to June 2021. All the neurectomies were performed using a plantar or dorsal approach. Outcomes were evaluated using visual analogue scale (VAS) scores, American Orthopedic Foot and Ankle Society (AOFAS) scores, the Foot and Ankle Ability Measure (FAAM), and complications. The appearance index (AI) was also used to assess the influence of foot appearance on the quality of life after surgery.

Results

Eight patients underwent neurectomy by the dorsal approach, and 12 patients underwent neurectomy by the plantar approach. The average follow-up time was 28.9 ± 12.9 months (range: 15–72 months). No statistically significant difference was found between the dorsal and plantar approach groups with respect to postoperative pain measured by the VAS score. The postoperative AOFAS scores and FAAM outcomes were not significantly different between the groups. The complications reported in the dorsal approach group were significantly less than those of the plantar group, mainly discomfort in wearing shoes. The AI of the plantar group and the dorsal group were significantly different.

Conclusion

The excision of the Morton’s neuroma by both the dorsal and plantar approach resulted in satisfactory outcomes. However, the foot appearance after surgery by the plantar approach had less influence on the quality of life than that using the dorsal approach. Our recommendation is that surgeons should choose the approach they are most familiar with and with which they are most confident in performing. In addition, the plantar approach is recommended if the patient needs a better appearance.

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.

A problem-based approach in musculoskeletal ultrasonography: central metatarsalgia

Ultrasonography (US) is a useful diagnostic method that can be easily applied to identify the cause of metatarsalgia. The superficial location of structures in the foot, dynamic capability of US, and the ability to perform direct real-time evaluations of the pain site are also strong advantages of US as a modality for examining the foot. Moreover, knowing the possible pain sources to investigate when a patient has a specific site of pain will enhance the diagnostic quality of US, and will help radiologists to perform US efficiently and effectively. The purpose of this article is to review the common etiologies of metatarsalgia including Morton’s neuroma, plantar plate injury, synovitis, tenosynovitis, bursitis, and metatarsal fractures, and to discuss their US features.

Medium-Term Results of Corticosteroid Injections for Morton's Neuroma

BACKGROUND

The objective of this study was to evaluate the medium-term results of corticosteroid injections for Morton's neuroma.

METHODS

This was a prospective follow-up study of a previous randomized controlled trial (RCT). Forty-five neuromas in 36 patients were injected with a single corticosteroid injection either with or without ultrasound guidance. As the results of the RCT showed no difference in outcomes between techniques, the data were pooled for the purpose of this study. Questionnaires were sent out and responses were collected via mail or telephone interview. Results were available in 42 out of 45 neuromas. There was a sex split of 68% female/32% male with a mean age of 62.6 years (SD, 12 years).

RESULTS

At mean follow-up of 4.8 years (SD, 0.91 years), the original corticosteroid injection remained effective in 36% (n = 16) of the patients. In these cases, the visual analog scale (VAS) pain score (P < .001) and Manchester-Oxford Foot Questionnaire Index (MOxFQ Index) (P = .001) remained significantly better than preintervention scores. The remaining cases underwent either a further injection or surgery. Fifty-five percent of the 11 neuromas that received a second injection continued to be asymptomatic in the medium term. Overall, 44% (n = 20) of the initial cohort underwent surgical excision by the medium-term follow-up. The VAS score, MOxFQ Index, and satisfaction scale score across all groups were not significantly different.

CONCLUSION

Corticosteroid injections for Morton's neuroma remained effective in over a third of cases for up to almost 5 years. A positive outcome at 1 year following a corticosteroid injection was reasonably predictive of a prolonged effect from the injection.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

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.

First webspace Morton's neuroma case report with literature review

Morton's neuromas are benign lesions of the inter-digital nerves within the foot. They are most commonly found in the second and third webspace. Morton's neuroma of the first webspace is very rare. A case of a 42-year-old female who presented complaining of long standing forefoot pain is presented. The patient was diagnosed with a soft tissue tumor in the 1st webspace. An excisional biopsy of the tumour confirmed a Morton's neuroma. Very few cases of Morton's neuroma in the first webspace have been reported in the literature.

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.

Anatomic basis for a new ultrasound-guided, mini-invasive technique for release of the deep transverse metatarsal ligament

Introduction

Morton's neuroma is an entrapment neuropathy of the third common plantar digital nerve, caused by the deep transverse metatarsal ligament (DTML). Minimally invasive or percutaneous surgery is a very common procedure, but surgical effectivity of this technique remains controversial. The goal of our study was to prove the effectiveness and safety of a new ultrasound‐guided technique for DTML‐release in a cadaver model.

Materials, Methods, and Results

The DTML was visualized in 10 fresh frozen donated body to science‐feet (eight male and two females, five left and five right) using an US device (GE Logic R7; 13 MHz linear probe, Madrid, Spain). Consecutively, minimally invasive ultrasound‐guided surgery was performed. Exclusion criteria of the donated bodies to science were previous history of forefoot surgery and space occupying mass lesions. The complete release of the ligament was achieved in all specimens without damage of any important anatomical structures as proven by anatomical dissection.

Conclusions

The results of this study indicate that our novel approach of an ultrasound‐guided release of the DTML is safer and more effective compared to blind techniques. The DTML could reliably be visualized and securely cut through a dorsal, minimally invasive surgical incision of only 2 mm.

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.

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)

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.

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.

Engineering the Echogenic Properties of Microfluidic Microbubbles Using Mixtures of Recombinant Protein and Amphiphilic Copolymers

Microbubbles are used as ultrasound contrast agents in medical diagnosis and also have shown great promise in ultrasound-mediated therapy. However, short lifetime and broad size distribution of microbubbles limit their applications in therapy and imaging. Moreover, it is challenging to tailor the echogenic response of microbubbles to make them suitable for specific applications. To overcome these challenges, we use microfluidic flow-focusing to prepare monodisperse microbubbles with a mixture of a recombinant amphiphilic protein, oleosin, and a synthetic amphiphilic copolymer, Pluronic. We show that these microbubbles have superior uniformity and stability under ultrasonic stimulation compared to commercial agents. We also demonstrate that by using different Pluronics, the echogenic response of the microbubbles can be tailored. Our work shows the versatility of using the combination of microfluidics and protein/copolymer mixtures as a method of engineering microbubbles. This tunability could potentially be important and powerful in producing microbubble agents for theranostic applications.

Prediction of Clinical Prognosis according to Intermetatarsal Distance and Neuroma Size on Ultrasonography in Morton Neuroma: A Prospective Observational Study

OBJECTIVES

This study aims to evaluate the clinical importance of intermetatarsal distance, size of neuroma, and proportion of neuroma in the intermetatarsal space in examinations of Morton neuroma using ultrasonography.

METHODS

Clinical prognosis was observed prospectively after corticosteroid injections in 136 patients with Morton neuroma, and the results were compared with ultrasonographic parameters of intermetatarsal distance, size of neuroma, and proportion of neuroma in the intermetatarsal space.

RESULTS

Twenty-one patients (15%) did not respond to corticosteroid injections and underwent surgical treatment for Morton neuroma. Logistic regression analysis and receiver operating characteristic curve analysis showed that the size of the neuroma was the sole predictor of failure of corticosteroid injections (P = .002). No other factors were significant for the prediction of clinical prognosis (P > .05).

CONCLUSIONS

The size of the neuroma on ultrasonography is the sole predictor of corticosteroid injection failure, while intermetatarsal distance and proportion of neuroma in the intermetatarsal space are not significant when predicting clinical prognosis of Morton neuroma.

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.

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.

Risk factors and the associated cutoff values for failure of corticosteroid injection in treatment of Morton's neuroma

BACKGROUND

Understanding the risk factors that predict the prognosis of Morton's neuroma after corticosteroid injection would help clinicians determine the appropriate treatment protocol. However, the cut-off values for the risk factors are unknown. The aim of this study was to identify the risk factors and cut-off values that predict failure of corticosteroid injection in treatment of Morton's neuroma.

METHOD

Among 201 patients who had corticosteroid injection for Morton's neuroma, 40 underwent further treatment after injections. Injection was performed with ultrasound guidance following ultrasound confirmation of the diagnosis. We compared demographic information, size of the neuroma, and other comorbidities between the patients who did and did not undergo further treatment after injection in order to determine the risk factors of failure. Receiver operating characteristic (ROC) curves were constructed to determine optimal cutoff values for each risk factor.

RESULTS

Stepwise logistic regression analysis showed that larger neuromas (p < 0.001) and younger patients (p = 0.026) predicted the failure of corticosteroid injection. The optimal cutoff value for the size of the neuroma was 6.3 mm (sensitivity, 81%; specificity, 95%; positive predictive value, 84%; negative predictive value, 88%) for predicting the failure of corticosteroid injection. Age was not associated with a specific cutoff value.

CONCLUSIONS

This study found that, with a cut-off value of 6.3 mm, larger Morton's neuromas were associated with failure of corticosteroid injection.

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.

Corticosteroid Injection for the Treatment of Morton's Neuroma: A Prospective, Double-Blinded, Randomized, Placebo-Controlled Trial

BACKGROUND

The effectiveness of corticosteroid injection for the treatment of Morton's neuroma is unclear. In addition, most of the studies related to it are case-control or retrospective case series. The purpose of this study was to compare the effectiveness between corticosteroid injection associated with local anesthetic and local anesthetic alone (placebo control group) for the treatment of Morton's neuroma.

METHODS

Forty-one patients with a diagnosis of Morton's neuroma were randomized to receive 3 injections of either a corticosteroid plus a local anesthetic or a local anesthetic alone. The patients and the researcher who collected data were blinded to the treatment groups. The visual analog scale for pain and the American Orthopaedic Foot & Ankle Score (metatarsophalangeal/interphalangeal score) were obtained at baseline, after each injection, and at 3 and 6 months after the last injection.

RESULTS

There were no significant between-group differences in terms of pain and function improvement at 3 and 6 months after treatment completion in comparison with baseline values. At the end of the study, 17 (48.5%) patients requested surgical excision of the neuroma: 7 (44%) in the experimental group and 10 (53%) in the control group ( P = 1.0).

CONCLUSION

The injection of a corticosteroid plus a local anesthetic was not superior to a local anesthetic alone in terms of pain and function improvement in patients with Morton's neuroma.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Outcomes following excision of Morton's interdigital neuroma: a prospective study

AIMS

This is the first prospective study to report the pre- and post-operative patient reported outcomes and satisfaction scores following excision of interdigital Morton's neuroma.

PATIENTS AND METHODS

Between May 2006 and April 2013, we prospectively studied 99 consecutive patients (111 feet) who were to undergo excision of a Morton's neuroma. There were 78 women and 21 men with a mean age at the time of surgery of 56 years (22 to 78). Patients completed the Manchester-Oxford Foot Questionnaire (MOXFQ), Short Form-12 (SF-12) and a supplementary patient satisfaction survey three months pre-operatively and six months post-operatively.

RESULTS

Statistically significant differences were found between the mean pre- and post-operative MOXFQ and the physical component of the SF-12 scores (p = 0.00081 and p = 0.00092 respectively). Most patients reported their overall satisfaction as excellent (n = 49, 49.5%) or good (n = 29, 29.3%), but ten patients were dissatisfied, reporting poor (n = 8, 8.1%) or very poor (n = 2, 2.0%) results. Only 63 patients (63%) were pain-free at follow-up: in eight patients (8.1%), the MOXFQ score worsened. There was no statistically significant difference in outcome between surgery on single or multiple sites. However, the MOXFQ scores were significantly worse after revision surgery (p = 0.004).

CONCLUSIONS

The patient-reported outcomes after resection of a symptomatic Morton's neuroma are acceptable but may not be as good as earlier studies suggest. Surgery at several sites can be undertaken safely but caution should be exercised when considering revision surgery. Cite this article: Bone Joint J 2016;98-B:1376-81.

Diagnostic Value of Elastography in the Diagnosis of Intermetatarsal Neuroma

The objective of the present study was to characterize the ultrasound and elastographic properties of intermetatarsal neuroma (interdigital neuroma) and their contribution to diagnosis. Eighteen patients with metatarsalgia, who had presented to an orthopedic clinic from April 2013 to February 2015, were diagnosed with 25 intermetatarsal neuromas (11 unilateral [61.11%], 7 bilateral [38.89%]). These patients underwent evaluation with ultrasonography and simultaneous ultrasound strain elastography to assess the elastographic properties of the tissues in the intermetatarsal space. The intermetatarsal neuroma diagnosis was confirmed by histopathologic inspection. The lesion contours, localization, dimensions, and vascularization were evaluated before surgical excision. The elasticity and strain ratio values were compared between the neuroma and adjacent healthy intermetatarsal space. Of the 25 intermetatarsal neuromas, 1 (4%) was not detected by ultrasonography (incidence of detection of 96%). The mean neuroma width was 6.35 (range 3.7 to 13) mm in the coronal plane, and the mean elasticity and strain ratio values were 3.44 (range 1.1 to 5.1) and 9.47 (range 2.3 to 19.3), respectively. The elasticity and strain ratio values were significantly greater in the presence of an interdigital neuroma than in the adjacent healthy intermetatarsal spaces (Z = -3.964, p = .0001 and Z = -3.927, p = .0001, respectively). The diagnostic cutoff values were calculated as 2.52 for elasticity and 6.1 for the strain ratio. Four neuromas (16%) were not demarcated, and the elasticity and strain ratio values for these were lower than those for neuromas with demarcated contours but were greater than those for healthy intermetatarsal spaces (p < .006 and p < .005, respectively). Patients with clinically suspected intermetatarsal neuromas that do not show demarcation and with smaller lesions might benefit from the use of ultrasound elastography for diagnosis.

Stump Neuroma

A 24-year-old man presented for follow-up magnetic resonance imaging to rule out tumor recurrence 1 year after he underwent an above-knee amputation for synovial cell sarcoma.

The accuracy of diagnostic ultrasound imaging for musculoskeletal soft tissue pathology of the extremities: a comprehensive review of the literature

Musculoskeletal diagnostic ultrasound imaging (MSK-DUSI) has been growing outside the traditional radiology speciality. Increased use of this technology has been reported in several healthcare settings, however an apparent gap in the knowledge of the accuracy of this diagnostic technology indicated a review was warranted. We undertook a structured review of the literature to assess the accuracy of MSK-DUSI for the diagnosis of musculoskeletal soft tissue pathology of the extremities. An electronic search of the National Library of Medicine’s PubMed database (1972 to mid-2014) was conducted. All relevant systematic reviews of diagnostic studies, all diagnostic studies published after the date of the latest systematic reviews and relevant diagnostic studies outside the scope the systematic reviews that directly compared the accuracy of MSK-DUSI (the index test) to an appropriate reference standard for the target condition were included. A fundamental appraisal of the methodological quality of studies was completed. The individual sensitivity, specificity and likelihood ratio data were extracted and entered into diagnostic accuracy tables. A total of 207 individual studies were included. The results show that MSK-DUSI has acceptable diagnostic accuracy for a wide spectrum of musculoskeletal conditions of the extremities. However, there is a lack of high quality prospective experimental studies in this area and as such clinicians should interpret the results with some caution due to the potential for overestimation of diagnostic accuracy.

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

The aim of the present study was to assess the diagnostic accuracy of 7 clinical tests for Morton's neuroma (MN) compared with ultrasonography (US). Forty patients (54 feet) were diagnosed with MN using predetermined clinical criteria. These patients were subsequently referred for US, which was performed by a single, experienced musculoskeletal radiologist. The clinical test results were compared against the US findings. MN was confirmed on US at the site of clinical diagnosis in 53 feet (98%). The operational characteristics of the clinical tests performed were as follows: thumb index finger squeeze (96% sensitivity, 96% accuracy), Mulder's click (61% sensitivity, 62% accuracy), foot squeeze (41% sensitivity, 41% accuracy), plantar percussion (37% sensitivity, 36% accuracy), dorsal percussion (33% sensitivity, 26% accuracy), and light touch and pin prick (26% sensitivity, 25% accuracy). No correlation was found between the size of MN on US and the positive clinical tests, except for Mulder's click. The size of MN was significantly larger in patients with a positive Mulder's click (10.9 versus 8.5 mm, p = .016). The clinical assessment was comparable to US in diagnosing MN. The thumb index finger squeeze test was the most sensitive screening test for the clinical diagnosis of MN.

Manipulation in the Treatment of Plantar Digital Neuralgia: A Retrospective Study of 38 Cases

OBJECTIVE

The purpose of this retrospective case series is to describe treatment outcomes for patients with plantar digital neuralgia (PDN) (Morton's neuroma) who were treated using foot manipulation.

METHODS

Charts were reviewed retrospectively for patients with a diagnosis of PDN and who received a minimum of 6 treatments consisting of manipulation alone. Visual analogue pain scales (VAS) and pressure threshold meter readings (PTM) were extracted as outcome measures.

RESULTS

Thirty-eight cases met inclusion criteria. Mean pretreatment duration of pain was 28 months. Mean pretreatment VAS was 69.5/100 mm. Mean pretreatment PTM was 2.54 Kp. By the sixth treatment, 30 (79%) of the 38 patients scored a VAS of 0 mm and a further 4 (10%) were below 10 mm. Contralateral limb PTM showed a mean pre-treatment score of 5.5 Kp, which rose slightly to 5.85 Kp. This compared to a pre-treatment score of 2.54 Kp rising to 5.86 Kp in the affected limb. This represents a 126% increase in the affected side compared to 6.5% in the unaffected limb. Statistical analysis demonstrated a significant linear trend between decreasing VAS and manipulation (P < .001).

CONCLUSION

The patients with PDN who were included in this case series improved with conservative care that included only foot manipulation.

Ultrasound versus magnetic resonance imaging for Morton neuroma: systematic review and meta-analysis

OBJECTIVES

To compare ultrasound (US) and magnetic resonance imaging (MRI) in the diagnosis of Morton's neuroma.

METHODS

Studies that assessed the diagnostic accuracy of US and MRI for Morton's neuroma were retrieved from major medical libraries independently by two reviewers up to 1 April 2014. Predefined inclusion and exclusion criteria were adopted.

RESULTS

277 studies were initially found, and the meta-analysis was conducted on 14 studies. US sensitivity was studied in five studies, MRI sensitivity in three studies, and bothin six studies. All studies used surgery as the reference standard. A high sensitivity (SE) of diagnostic testing was observed for both US (SE (95 % CI) = 0.91 (0.83-0.96)) and MRI (SE (95 % CI) = 0.90 (0.82-0.96)) with no significant differences between the two modalities in diagnosis (Q test p = 0.88). For MRI, specificity of test was 1.00 with a pooled estimation of 1.00 (0.73-1.00), while the pooled specificity was 0.854 (95 % CI: 0.41-1.00) for US. No differences were observed between US and MRI in study design (p = 0.76).

CONCLUSION

This meta-analysis shows that the SE of US (0.91) is equal to (p = 0.88) that of MRI (0.90) for identification of Morton's neuroma.

KEY POINTS

• For Morton's neuroma, US sensitivity is equal to MRI. • US is as accurate as MRI in diagnosing Morton's neuroma. • US may be the most cost-effective imaging method for Morton's neuroma.

Entrapment neuropathy about the foot and ankle: an update

Occurrences of entrapment neuropathies of the lower extremity are relatively infrequent; therefore, these conditions may be underappreciated and difficult to diagnose. Understanding the anatomy of the peripheral nerves and their potential entrapment sites is essential. A detailed physical examination and judicious use of imaging modalities are also vital when establishing a diagnosis. Once an accurate diagnosis is obtained, treatment is aimed at reducing external pressure, minimizing inflammation, correcting any causative foot and ankle deformities, and ultimately releasing any constrictive tissues.

Metatarsalgia and Morton's Disease: Comparison of Outcomes Between Open Procedure and Neurectomy Versus Percutaneous Metatarsal Osteotomies and Ligament Release With a Minimum of 2 Years of Follow-Up

The present study compared the clinical results of open neurectomy versus a percutaneous procedure for Morton's disease. This was a retrospective study comparing the functional results after 2 surgical procedures: open neurectomy and a percutaneous procedure (with deep transverse metatarsal ligament release and distal metatarsal osteotomies). The present study included 52 patients (26 in each group), and the mean follow-up period was 4 (range 2 to 7) years. The patient evaluation criteria included the presence of painful symptoms of Morton's disease, American Orthopaedic Foot and Ankle Society (AOFAS) functional scale score, patient satisfaction, and delay for recovery. Percutaneous treatment of Morton's disease and open neurectomy produced complete relief of pain in 25 of 26 patients in each group. At the latest follow-up visit, the mean AOFAS score had significantly improved from 36 ± 11 preoperatively to a mean of 89 ± 18 (p < .001). After 2 years, the functional improvement obtained with the percutaneous procedure persisted, with a stable AOFAS score (96 ± 10). Persistent metatarsalgia was reported by patients who had undergone open neurectomy, with a significantly decreased AOFAS score (81 ± 21, p = .009). The percutaneous procedure for Morton's disease provided excellent functional outcomes (AOFAS score >90) significantly more often with a shorter delay than after open neurectomy (p = .03). At the latest follow-up visit, metatarsalgia due to plantar hyperpressure or bursitis and requiring plantar orthotics was present in 11 of 26 patients (44%) after open neurectomy and in 1 of 26 patients (4%) after the percutaneous procedure (p = .002). Percutaneous treatment of Morton's disease is a reliable procedure providing results as good as those after open neurectomy, with significantly better outcomes in the longer term and a lower rate of late metatarsalgia.

The accuracy of ultrasonography and magnetic resonance imaging for the diagnosis of Morton's neuroma: a systematic review

AIM

To determine the accuracy of MRI versus ultrasound for Morton's neuroma.

MATERIALS AND METHODS

A search was undertaken for clinical studies published in any language in PubMed up to the date of December 2013. Studies assessing the accuracy of the ultrasound or MRI for the diagnosis of Morton's neuroma were included. Data were pooled for meta-analysis. Study selection, data collection, and extraction were performed independently by two authors. Meta-disc 1.4 and Revman 5.2 software were applied for statistical analysis.

RESULTS

The study included 12 studies; 217 patients underwent MRI and 241 underwent ultrasound examinations. There appeared greater diagnostic accuracy for ultrasound than MRI for the diagnosis of Morton's neuroma (ultrasound sensitivity 90%, specificity 88%, positive likelihood ratio 2.77, negative likelihood ratio 0.16 versus MRI sensitivity 93%, specificity 68%, positive likelihood ratio 1.89, negative likelihood ratio 0.19).

CONCLUSIONS

The available evidence suggests that ultrasound can provide better accuracy for the diagnosis of Morton's neuroma than MRI.

Role of MRI in detection of Morton's neuroma

BACKGROUND

Distinguishing between patients with a true Morton's neuroma and other forefoot pathology can be difficult. The aim of this study was to evaluate the diagnostic accuracy of routine magnetic resonance imaging (MRI) when compared to clinical examination for Morton's neuroma.

METHODS

We retrospectively identified 71 patients who underwent operative treatment due to the diagnosis of Morton's neuroma between 2007 and 2013. All patients had a MRI preoperative. Our study group comprised 58 female and 13 male patients with a mean age of 57 (range, 38-92) years. We compared the results of preoperative MRI and the patient's clinical assessment with postoperative histopathological results.

RESULTS

Typical clinical signs were found in 65 cases. Most common symptoms were plantar pain (92%) and increased pain on walking (89%). A Morton's neuroma was detected on MRI in 59 of 71 cases. Its sensitivity was 0.84 and its specificity was 0.33. The positive and negative predictive values were 0.97 and 0.08, respectively. For the presence of main clinical symptoms we found a sensitivity of 0.94 and a specificity of 0.33. The positive predictive value was 0.97 and the negative predictive value was 0.20.

CONCLUSION

MRI under routine conditions had a good detection rate for the evaluation of Morton's neuroma. However, its accuracy was not as high as the accuracy of clinical assessment.

LEVEL OF EVIDENCE

Level IV, retrospective series.

Contribution of a new electrophysiologic test to Morton's neuroma diagnosis

BACKGROUND

Morton's neuroma causes metatarsalgia due to the interdigital neuropathy. The small nerve diameter compromises their evaluation in image studies. To overcome this problem we propose a new electrophysiological test.

METHODS

We conducted a prospective case-control study performing a orthodromic electroneurography using subdermal electrodes in controls and patients to assess the validity. Additionally all patients were tested with magnetic resonance. Some patients required surgery and subsequent histological evaluation.

RESULTS

The new ENG procedure showed higher sensitivity and specificity. Methodological standardization was easy and the test was well tolerated by the subjects.

CONCLUSIONS

Our test demonstrated remarkable diagnostic efficiency, and also was able to identify symptomatic patients undetected by magnetic resonance, which underlines the lack of correlation between the size and intensity of the lesion. This new electrophysiological method appears to be a highly sensitivity, well-tolerated, simple and low-cost for Morton's neuroma diagnosis.

Metatarsalgia, lesser toe deformities, and associated disorders of the forefoot

Forefoot pain in the adult often alters mobility and has a negative impact on quality of life. Metatarsalgia describes pain localized to the forefoot. Forefoot pain may be caused by conditions of the lesser toes themselves (eg, hammertoes, mallet toes, claw toes). The pathophysiology of lesser toe deformities is complex and is affected by the function of intrinsic and extrinsic muscle units. In addition to lesser toe and metatarsal abnormality, forefoot pain can be attributed to interdigital neuritis, disorders of the plantar skin, and gastrocsoleus contracture. Treatment of these conditions may include shoe modifications, appliances, therapeutic exercises, and surgical repair.

Metatarsal shortening osteotomy for decompression of Morton's neuroma

BACKGROUND

Among the various operative treatments of Morton's neuroma, deep transverse metatarsal ligament (DTML) release has been performed for decompression of neuroma. However, the main lesion of Morton's neuroma is located between the metatarsal head and the metatarsophalangeal (MTP) joint and more distal than the DTML. Hence we performed the metatarsal shortening osteotomy along with DTML release for decompression of neuroma, and investigated the clinical outcomes of it and compared the outcomes with those of DTML release alone.

METHODS

We retrospectively reviewed 84 consecutive patients (86 neuromas) who underwent surgery for a Morton's neuroma between February 2008 and March 2011. The first 46 neuroma (group A) were treated with DTML release alone, and the next 40 neuroma (group B) underwent the metatarsal shortening osteotomy with DTML release. Clinical outcomes were compared between the groups and the associations between clinical outcomes and neuroma size were assessed.

RESULTS

Clinical outcomes were significantly improved after surgery in both groups but there were significant differences in clinical outcomes between the 2 groups at final follow-up. There were significant correlations between neuroma size and outcomes in group A, whereas no significant correlations were found between neuroma size and outcomes in group B.

CONCLUSION

The metatarsal shortening osteotomy with DTML release resulted in better outcomes compared with DTML release alone in patients with Morton's neuromas.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

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

Morton's neuroma is a common condition mainly affecting middle aged women, and there are many proposed etiological theories involving chronic repetitive trauma, ischemia, entrapment, and intermetatarsal bursitis. Incorrect terminology suggests that the underlying pathological process is a nerve tumor, although histological examination reveals the presence of inflammatory tissue-that is, perineural fibrosis. The common digital nerve and its branches in the third planter webspace are most commonly affected. Diagnosis is usually made through history taking and clinical examination but may be aided by ultrasonography and magnetic resonance imaging. Current nonoperative treatment strategies include shoe-wear modifications, custom made orthoses, and injections of local anesthetic agents, sclerosing agents, and steroids. Operative management options primarily involve either nerve decompression or neurectomy. We have reviewed the published literature to evaluate the outcomes of the available diagnostic modalities and treatment options and present an algorithm for clinical practice.

Surgical treatment of Morton's neuroma: clinical results after open excision

PURPOSE

Long-term results following surgical treatment of Morton neuroma are rare. The purpose of the present study was to evaluate patients after excision of Morton's neuroma at least ten years following surgery.

METHODS

We performed a retrospective review of the patients' records who underwent excision of an interdigital neuroma with the clinical diagnosis of Morton's neuroma. Eighty-one patients who had undergone surgery on 98 feet were analysed at an average of 15.3 years postoperatively. In total 111 neuromas were excised, because in 13 feet more than one neuroma was identified clinically. Follow-up evaluation included physical examination and a radiographic evaluation. The interdigital neuroma clinical evaluation score and the AOFAS score were assessed.

RESULTS

An excellent result was reported for 44 feet (44.9 %), a good result for 31 feet (31.6 %) and a fair one for 15 feet (15,3 %). Eight feet had a poor result (8.2 %), in all of them an amputation neuroma was diagnosed. The average neuroma score was 62 points (range 20-80) and the AOFAS score 75 points (range 29-100). Sixty-one feet (62.2 %) had concomitant foot and ankle disorders not related to the primary diagnosis of Morton's neuroma. Numbness was assessed in 72 % (72 feet), a normal sensibility in 26 % (26 feet) and dyaesthesia in 1 % (one foot). The clinical outcome was not influenced by existence of sensory deficits (p = 0.646); analysis of location of neuroma showed best results for those in the third webspace. A significantly worse outcome was found in patients operated on multiple neuromas compared to single neuroma (p = 0.038).

CONCLUSION

Surgical excision of a Morton's neuroma results in good clinical results and high overall patient's satisfaction in the long term. Multiple neuromas have worse outcome than single neuromas. Sensory deficits and concomitant foot and ankles disorders are common, but do not have an influence on patient's satisfaction.

Rheumatoid nodule presenting as Morton's neuroma

Among 101 feet that presented with symptoms and signs similar to Morton’s neuroma, intermetatarsal rheumatoid nodules were found in five feet (three patients). Two patients had bilateral involvement. Histology of the excised tissue showed the presence of a rheumatoid nodule and Morton’s neuroma in four feet and a rheumatoid nodule with unremarkable nerve bundles in one. A rheumatoid nodule can coexist with Morton’s neuroma, as seen in our patients, and the presentation is often similar to that of a Morton’s neuroma. Our patients were rendered asymptomatic with surgical treatment and went on to have appropriate management of rheumatoid arthritis. Rheumatoid nodule should be considered in the differential diagnosis of Morton’s neuroma in not only rheumatoid arthritis patients but also asymptomatic patients who have never been tested for rheumatoid antibodies.

Ultrasonography and magnetic resonance imaging in the diagnosis of Morton's neuroma

BACKGROUND

Magnetic resonance imaging (MRI) and ultrasonography are used widely for the diagnosis of Morton's neuroma. The aim of this study was to assess the accuracy of these two modalities as diagnostic tools in Morton's neuroma.

METHODS

Fifty feet of 47 consecutive patients (39 women and 8 men; mean age, 46 years; age range, 36-64 years) who presented between January 1, 2005, and June 30, 2008, were included in the study. Twenty-five feet were investigated with ultrasonography and 25 with MRI. Morton's neuroma was confirmed surgically and histologically in all of the patients. A Student unpaired t test was applied.

RESULTS

Twenty-two MRIs were diagnostic (sensitivity, 88%). Three patients with negative MRI findings underwent ultrasonography and were found to have a neuroma smaller than 5 mm. Twenty-four ultrasound scans demonstrated the neuroma (sensitivity, 96%), with five neuromas being smaller than 5 mm.

CONCLUSIONS

Ultrasonography has a slightly higher sensitivity in the diagnosis of Morton's neuroma, particularly of neuromas smaller than 5 mm, and should be the preferred imaging modality in suspected cases, and MRI should be reserved for cases with equivocal diagnosis.

Efficacy of corticosteroid injection versus size of plantar interdigital neuroma

BACKGROUND

The aim of this prospective study was to assess the effectiveness of a single ultrasound-guided steroid injection in the treatment of Morton's neuromas and whether the response to injection correlates with the size of the neuroma.

METHODS

Forty-three patients with clinical features of Morton's neuroma underwent ultrasound scan assessment. Once the lesion was confirmed in the relevant web space, a single corticosteroid injection was given using 40 mg of methylprednisolone along with 1% lidocaine. All scans and injections were performed by a single musculoskeletal radiologist. Patients were divided into two groups on the basis of the size of the lesion measured on the scan. Group 1 included patients with neuromas of 5 mm or less and group 2 patients had neuromas larger than 5 mm. A visual analog scale (VAS) for pain (scale 0 to 10), the American Orthopaedic Foot and Ankle Society (AOFAS) score, and the Johnson satisfaction scale were used to assess patients before injection and then at 6 weeks, 6 months, and 12 months following the injection. Thirty-nine patients had confirmed neuromas. Group 1 (lesion ≤ 5 mm) included 17 patients (mean age, 30 years) (7 males, 10 females) and group 2 (lesion >5 mm) had 22 patients (mean age, 33 years) (8 males, 14 females).

RESULTS

VAS scores, AOFAS scores, and Johnson scale improved significantly in both groups at 6 weeks (p < .0001). At 6 months postinjection, this improvement remained significant only in group 1 with all scores (p < . 001). At 12 months, there was no difference between both groups and outcome scores nearly approached preinjection scores. At the final review, two patients in group 1 and four patients in group 2 had severe recurrent symptoms and therefore underwent surgical excision of the neuroma after they rejected the offer for a repeat injection (p = 0.6).

CONCLUSION

A single ultrasound-guided corticosteroid injection resulted in generally short-term pain relief for symptomatic Morton's neuromas. The effectiveness of the injection appears to be more significant and long-lasting for lesions smaller than 5 mm.

Prevalence of interdigital nerve enlargements in an asymptomatic population

BACKGROUND

Morton's neuroma is a common primary diagnosis for referral to foot and ankle surgeons. On presentation, many patients have had an ultrasound reporting the presence of Morton's neuroma, which may not correlate with the clinical examination findings. The prevalence of such sonographic findings in the general population remains unknown.

METHODS

In this observational prospective study, patients with asymptomatic forefeet who were seen by two foot and ankle surgeons for unrelated mid- or hind foot pathology were examined clinically and sonographically for the presence of interdigital nerve thickening. Forty-eight volunteers participated in the study (96 feet). For the purpose of this study, asymptomatic thickenings greater than 5 mm in diameter were termed sonographic neuromas. Ultrasound examination was performed by two specialist musculoskeletal radiologists.

RESULTS

Fifty-four percent of the volunteers (26 of 48) had sonographic nerve thickening and in 17 cases (35.4%) enlarged nerves were found bilaterally. Differences for gender, original diagnosis or side of original pathology were not significant. Older subjects were more likely to have a sonographic neuroma (p = 0.018). Feet with a positive Mulder's click were more likely to have a sonographic neuroma (p = 0.015).

CONCLUSION

Ultrasound, even in highly skilled hands, has a high rate of incidental finding of an asymptomatic interdigital nerve enlargement, which can lead to a false diagnosis of a Morton's neuroma. Sonographic evidence of Morton's neuroma per se is unreliable unless it is correlated with an equivocal clinical examination. Clinical examination is still the gold standard for the diagnosis of a Morton's neuroma.

Therapeutic Massage Provides Pain Relief to a Client with Morton's Neuroma: A Case Report

BACKGROUND

Morton's neuroma is a common cause of pain that radiates from between the third and fourth metatarsals and which, when symptomatic, creates sensations of burning or sharp pain and numbness on the forefoot. Many conservative and surgical interventions are employed to reduce associated pain, but not enough research has been conducted to recommend patients to any one approach as the most reliable source of pain management.

PURPOSE

The objective of this case report is to describe the effect of massage therapy on one woman with symptomatic Morton's neuroma.

PARTICIPANT

A physically active 25-year-old female with diagnosed symptomatic Morton's neuroma who has not found relief with previous conservative intervention.

INTERVENTION

Six session of massage therapy once weekly for 60-75 minutes focused on postural alignment and localized foot and leg treatment. The client also completed an at-home exercise each day. Change was monitored each week by the massage therapist reassessing posture and by the client filling out a pain survey based on a Visual Analog Scale.

RESULTS

The client reported progressive change in the character of the pain from burning and stabbing before the first session to a dull, pulsing sensation after the third session. She also recorded a reduction in pain during exercise from a 5/10 to 0/10 (on a scale where 10 is extreme pain).

CONCLUSION

This study describes how massage therapy reduced pain from Morton's neuroma for one client; however, larger randomized control studies need to be done in order to determine the short- and long-term effects of massage therapy on this painful condition.

MRI and ultrasonography in Morton's neuroma: Diagnostic accuracy and correlation

BACKGROUND

The diagnosis of Morton's neuroma is based primarily on clinical findings. Ultrasonography (US) and magnetic resonance image (MRI) studies are considered complementary diagnostic techniques. The aim of this study was to establish the correlation and sensitivity of both techniques used to diagnose Morton's neuroma.

MATERIALS AND METHODS

Thirty seven patients (43 intermetatarsal spaces) with Morton's neuroma operated were retrospectively reviewed. In all cases MRI or ultrasound was performed to complement clinical diagnosis of Morton's neuroma. In all cases, a histopathological examination confirmed the diagnosis. Estimates of sensitivity were made and correlation (kappa statistics) was assessed for both techniques.

RESULTS

Twenty seven women and 10 men participated with a mean age of 60 years. Double lesions presented in six patients. The second intermetatarsal space was affected in 10 patients and the third in 33 patients. An MRI was performed in 41 cases and a US in 23 cases. In 21 patients, both an MRI and a US were performed. With regard to the 41 MRIs performed, 34 were positive for Morton's neuroma and 7 were negative. MRI sensitivity was 82.9% [95% confidence interval (CI): 0.679-0.929]. Thirteen out of 23 US performed were positive and 10 US were negative. US sensitivity was 56.5% (95% CI: 0.345-0.768). Relative to the 21 patients on whom both techniques were carried out, the agreement between both techniques was poor (kappa statistics 0.31).

CONCLUSION

Although ancillary studies may be required to confirm the clinical diagnosis in some cases, they are probably not necessary for the diagnosis of Morton's neuroma. MRI had a higher sensitivity than US and should be considered the technique of choice in those cases. However, a negative result does not exclude the diagnosis (false negative 17%).

Morton's neuroma: A clinical versus radiological diagnosis

BACKGROUND

The aim of our study was to compare the clinical versus radiological diagnosis of patients suffering from a Morton's neuroma.

METHODS

Clinical assessments and pre-operative radiological imaging of patients who had excision of a Morton's neuromas were retrospectively compared.

RESULTS

43 neuromas were excised from 36 patients over 68 months. The commonest clinical symptoms were tenderness on direct palpation (100%), pain on weight bearing (91%) which was relieved by rest (81%). The most sensitive clinical sign was a Mulder's click. Clinical assessment had a sensitivity of 98% (42/43). Ultrasonography had a sensitivity of 90% (28/31) and magnetic resonance imaging had a sensitivity of 88% (14/16).

CONCLUSION

There is no absolute requirement for imaging patients who clinically have a Morton's neuroma. The two main indications for imaging are (a) an unclear clinical assessment and (b) cases when more than one web space is affected. Ultrasonography should be the investigation of choice.

High resolution imaging of tunnels by magnetic resonance neurography

Peripheral nerves often traverse confined fibro-osseous and fibro-muscular tunnels in the extremities, where they are particularly vulnerable to entrapment and compressive neuropathy. This gives rise to various tunnel syndromes, characterized by distinct patterns of muscular weakness and sensory deficits. This article focuses on several upper and lower extremity tunnels, in which direct visualization of the normal and abnormal nerve in question is possible with high resolution 3T MR neurography (MRN). MRN can also serve as a useful adjunct to clinical and electrophysiologic exams by discriminating adhesive lesions (perineural scar) from compressive lesions (such as tumor, ganglion, hypertrophic callous, or anomalous muscles) responsible for symptoms, thereby guiding appropriate treatment.