Presurgical Perspective and Postsurgical Evaluation of Morton's Neuroma and Other Nerve Lesions.

Magnetic resonance imaging (MRI) is a robust method used for both preoperative and postoperative evaluation of Morton's neuroma and other neural lesions. MRI is used to confirm the diagnosis and for precise localization, estimation of outcome, and differential diagnoses. The differential diagnoses include mechanically induced plantar plate ruptures with associated Morton's neuroma-like tumors in the intermetatarsal/interdigital spaces; mechanical fibrosis cushion formations and pseudo bursae in the plantar foot adipose tissue; rheumatologic affections, such as rheumatoid nodules, gouty nodules, and intermetatarsal bursitis; and lastly the tenosynovial giant cell tumor (formerly called pigmented villonodular synovitis). In the postoperative evaluation after resection of Morton's neuroma, the same differential diagnoses must be considered as in the preoperative evaluation. Similarly, a high prevalence (up to 25%) of asymptomatic Morton's neuroma-like findings in the intermetatarsal and interdigital spaces should be kept in mind when interpreting postoperative recurrent forefoot pain after Morton's neuroma resection.

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.

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.

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.

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

BACKGROUND: The purpose of this research was to see if there were any differences in peak pressure, contact time, pressure-time integrals, and geometric variables such as forefoot width, foot length, coefficient of spreading, and arch index between subjects with Morton's neuroma (MN) and control subjects. METHODS: Dynamic peak plantar pressure, contact time, pressure-time integral, and geometric data were extracted using the EMED-X platform in 52 subjects with MN and 31 control subjects. Differences in peak pressure, contact time, pressure-time integral, and geometric data between participants with and those without MN were determined using independent-samples t tests. There were no significant differences in age, weight, height, and body mass index between patients with MN and control subjects. RESULTS: There were no significant differences in the peak pressures of all masked areas and pressure-time integrals under metatarsal 2 to 4 heads between patients with MN and control subjects. In addition, no significant differences were observed between patients with MN and control subjects in geometric measurements of forefoot length, width, coefficient of spreading, foot progression angle, and arch index. CONCLUSION: No relationship was found in this study between peak pressure, contact time, and pressure-time integral under the metatarsal heads, forefoot width, foot length, coefficient of spreading, and foot progression angle in a symptomatic MN group compared with a control group. The need to perform osteotomies to treat MN not associated with other lesser metatarsal phalangeal joint pathologies is questionable. LEVEL OF EVIDENCE: Level III, Case-Control Study.

Synovial Sarcoma of the Digits: A Case Report of an Unplanned Excision.

Synovial sarcoma is a rare occurrence in the lower extremity, although the presenting symptoms can mimic those of other more common and benign musculoskeletal pathologies. We present the case of a patient who was originally thought to have a Morton's neuroma or ganglionic cyst. The correct diagnosis, synovial sarcoma, was determined only after an unplanned excision. Despite the patient presenting with symptoms similar to those of a compressive neuropathy, a high index of suspicion should be present when a patient presents with any soft tissue mass, especially if it has an unusual clinical appearance to avoid an unplanned excision.

The role of the width of the forefoot in the development of Morton's neuroma.

AIMS: Morton's neuroma is common condition of the forefoot, but its aetiology remains unclear. Our aim was to evaluate the relationship between the width of the forefoot and the development of a Morton's neuroma. PATIENTS AND METHODS: Between January 2013 and May 2016, a total of 84 consecutive patients (17 men, 67 women) with a unilateral Morton's neuroma were enrolled into the study. The involved and uninvolved feet of each patient were compared. A control group of patients with symptoms from the foot, but without a neuroma who were matched for age, gender, affected side, and web space location, were enrolled. The first to fifth intermetatarsal distance, intermetatarsal angle and intermetatarsal distance of involved web space on standing radiographs were assessed. RESULTS: The inter- and intra-observer reliability was excellent. The three parameters did not differ significantly between the involved and uninvolved feet. Neither did they differ significantly between the patients and the controls. CONCLUSION: We conclude that there is no significant relationship between the width of the forefoot and the development of a Morton's neuroma. Cite this article: Bone Joint J 2017;99-B:365-8.

Neurectomy for Bilateral Morton's Neuroma A Case Report of a Male Patient.

Morton's neuroma is a common condition that mainly affects middle-aged women, and many articles have addressed the surgical treatment of this condition. Previous reports have described bilateral neuroma excision in women but not in men. We report a rare case of bilateral neuromas in a male patient treated with simultaneous neurectomy.

Management of Painful Recurrent Intermetatarsal Neuroma Using Processed Porcine Extracellular Matrix Material: A Case Report.

Painful recurrent stump neuroma presents a common clinical problem following the transection of a nerve after initial interdigital neuroma excision but there is no gold standard of treatment. A patient presented with pain symptoms consistent with recurrent intermetatarsal stump neuroma after undergoing previous surgery to excise a Hauser neuroma. The recurrent stump neuroma was excised and the resulting nerve was capped and implantation into intrinsic muscle. Postoperatively, the patient experienced a complete resolution of pain and return of normal function. This article discusses capping material characteristics and considers the factors that may contribute to clinical success.