Intermetatarsal Neuroma Research Articles

449 The Efficiency of Non-surgical Therapies for the Treatment of Mortons Neuroma: A Systematic Review

INTRODUCTION: Morton’s neuroma or Intermetatarsal neuroma is a benign inflammation of the peripheral nerves in the feet causing sharp, burning metatarsalgia and significant morbidity while walking, running, etc. It occurs more in females because tight shoe styles put pressure on the nerve. METHODS: Keyword search of “Morton’s Neuroma”, “treatment”, “conservative” and “non-surgical” was conducted across MEDLINE, EMBASE, and Cochrane databases. Two cohort studies and seven Randomised Controlled Trials were included for review following PRISMA guidelines. These studies were reviewed for pain relief, functionality, and limitations of each procedure. RESULTS: Methylprednisolone injections were proved to reduce the Visual Analog Scale score with >50% cases showing no difficulty in functional daily activity at 9 months post-procedure. Short-term relief was achieved by alcohol and capsaicin injections independently. Modifications in the shoe insole indicated better functionality and analgesia compared to a flat insole but combined with steroids it showed better outcomes. Extracorporeal shockwave therapy provided relief for up to 3 months compared to radiofrequency ablation which provided relief for a longer period. CONCLUSIONS: Although these procedures show statistically significant changes, they are not without limitations. Well-designed randomized controlled trials looking into the avenues for radiofrequency ablation and shockwave therapies as opposed to surgical excision of neuromas are vital.

“Morton’s Neuroma” — Term Etymology: A Review

Background. The urgency of the problem is explained by a high morbidity rate and the need to verify the diagnosis with related specialists (ultrasound physicians, radiologists, trauma surgeons, pathologists), as well as by significant difficulties in patient routing and high probability of primary referral to neurologists, neurosurgeons, and general practitioners. In modern Russian literature, neuromas of all interdigital spaces are identified with Morton’s neuroma.
 Aim of the review was to determine the accuracy of modern medical terminology, in particular of the term «Morton’s neuroma», to reveal the spectrum of eponyms unacceptable for communication with related specialists and patients, to fill the historical gap and to attract the scientific medical community to discussion on this topic.
 Methods. We identified 40 articles on this topic published from 1845 to 2022. The search was performed in PubMed/MEDLINE and eLIBRARY databases.
 Results. Evolution, history, and etymology of several terms used for intermetatarsal neuroma are covered in the study, based on the analysis of literature sources. It has been found that a number of eponyms used to designate neuromas are historically inaccurate. In addition, we have discovered that the reports of «nerve fibrosis» were encountered prior to the introduction of the term «neuroma». However, most authors have popularized the nominal term «Morton’s neuromas».
 Conclusions. An obvious contradiction between the etiopathogenesis of neuroma and the term itself can be confusing for clinicians and diagnosticians. In our opinion, the disease known nowadays as «Morton’s neuroma» should be named «fibrosis of the plantar nerve of the third toe», and the name terms denoting the number of the corresponding interdigital space should be replaced by the number of the corresponding common plantar digital nerve.

Adverse To Converse

Toe Pain--- Cross-Country HISTORY: A 12 year-old female cross country runner presented to the pediatric sports medicine clinic with 3 months of right second toe pain. Initially, the pain started after stubbing her toe. She developed a constant dull ache that was present at rest and worsened with prolonged walking and during cross country. She noted that her symptoms gradually worsened with time, and she was having no improvement with rest, icing and anti-inflammatories. PHYSICAL EXAMINATION: Overlying skin with no rashes or lesions. Tenderness along the plantar surface of her right second metatarsophalangeal (MTP) joint. ROM was limited in both passive and active flexion and extension of the affected joint. Sensation was intact, and strength with flexion and extension of the toe was normal, however there was significant pain with testing. MT squeeze test was negative. Varus and valgus stress to MTP joint elicited no laxity, and “drawer test” of MTP joint showed mild instability. DIFFERENTIAL DIAGNOSIS: 1. Sprain of plantar plate 2. Metatarsal fracture/stress fracture 3. Osteochondrosis of the metatarsal head 4. Metatarsalgia 5. Lisfranc injury 6. Intermetatarsal neuroma TEST RESULTS: X-ray R foot: --- Flattening of the second metatarsal head. MRI R foot without contrast: --- Flattening/collapse of the 2nd metatarsal head/distal epiphysis with prominent marrow edema of the 2nd metatarsal head and neck. Mild MTP joint space narrowing. FINAL/WORKING DIAGNOSIS: Osteochondrosis of the metatarsal head (Freiberg Disease) - Stage 4 TREATMENT AND OUTCOMES: 1. Placed in short leg walking boot with protected weight-bearing, ice 1-2 times daily, Foot/Ankle Surgery consultation with discussion of conservative care vs surgical (chondral drilling and/or chondroplasty). Patient opted for conservative care. 2. At 4-week follow-up, patient’s pain significantly reduced. Continued walking boot additional 4 weeks with transition into stiff-soled shoe. 3. At 8-weeks post treatment, follow-up MRI showed no progression of disease. Clinically with almost complete resolution of pain. 4. By 10 weeks, transitioned into a custom foot orthotic with added support to float 2nd MTP joint. Restrictions included low impact sports only with plan for repeat MRI at 6 months.

Radiofrequency Ablation for the Treatment of Painful Neuroma

Mechanical compression of interdigital nerves beneath the deep transverse intermetatarsal ligament and between the metatarsal heads leads to painful irritation and possible fibrosis. Conservative measures of padding and injections often fail to provide long-term relief. Surgical excision provides definitive relief, but the procedure is not without risk. Incomplete excision and stump neuroma formation are a few of the possible complications associate with open excision. This retrospective cohort study was performed to provide a review of the available literature on the identification and treatment of interdigital neuromas and to examine the overall incidence of patient satisfaction after radiofrequency ablation as definitive treatment for interdigital neuroma formation. This study population consisted of 32 patients (25 females and 7 males with 1 patient having bilateral procedures) with a mean age of 46.3 ± 17 (range 31 to 65) years. For all procedures, the median patient satisfaction score was 92.5 (interquartile range 50 to 100) of 100, with a mean follow-up period of > 2.5 years. Only 1 patient in the study population reported no relief after 3 total procedures. Radiofrequency ablation offers a minimally invasive alternative with a short postoperative recovery course and considerably fewer complications compared with surgical excision of the intermetatarsal neuroma as described in prior reports.

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

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

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.

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

BackgroundThe main purpose of this study was to investigate the presence of an association between intermetatarsal neuroma and foot type, as measured by the Foot Posture Index. The study also examined whether there was a relationship between foot type and the interspace affected with intermetatarsal neuroma, and whether ankle equinus or body mass index had an effect.MethodsIn total, 100 participants were recruited from The University of Western Australia’s Podiatry Clinic, 68 of whom were diagnosed with inter-metatarsal neuroma from 2009 to 2015. There were 32 control participants recruited from 2014 to 2015. The age of subjects was recorded, as were weight and height, which were used to calculate body mass index. The foot posture index and ankle dorsiflexion were measured using standard technique. Independent t-tests and Kruskal-Wallis tests were used to compare differences in foot posture index, body mass index and ankle dorsiflexion between the inter-metatarsal neuroma and control groups. Multivariable logistic regression was also used to model relationships for outcome.ResultsThe 68 intermetatarsal neuroma subjects had a mean age of 52 years (range 20 to 74 years) and comprised of 56 females and 12 males. The 32 control subjects had a mean age of 49 years (range 24 to 67 years) with 26 females and six males. There were no significant differences between the control and the intermetatarsal neuroma groups with respect to the mean foot posture index scores of the left and right foot (p = 0.21 and 0.87, respectively). Additionally no significant differences were detected between the affected intermetatarsal neuroma interspace and foot posture index (p = 0.27 and 0.47, respectively). There was no significant difference in mean body mass index between the intermetatarsal neuroma (26.9 ± 5.7) and control groups (26.5 ± 4.1) (p = 0.72). There was, however, a significant difference in mean ankle dorsiflexion between the intermetatarsal neuroma and control groups (p < 0.001 for both feet). Logistic regression models, adjusted for age, sex, foot posture index and body mass index estimated that the odds of having an intermetatarsal neuroma in the right foot increased by 61% (OR 1.61; 95% CI 1.32–1.96) with each one degree reduction of ankle dorsiflexion, and in the left foot by 43% (OR 1.43; 95% CI 1.22–1.69).ConclusionNo relationships were found between foot posture index and body mass index with intermetatarsal neuroma, or between foot posture index and the interspaces affected. However, a strong association was demonstrated between the presence of intermetatarsal neuroma and a restriction of ankle dorsiflexion.

Minimally invasive endoscopic decompression of the intermatatarsal nerve for Morton's neuroma

BackgroundWe presented case reports of endoscopic decompression for a Morton intermetatarsal neuroma. MethodsThree patients underwent surgery using an instrument designed to release the transverse carpal ligament for carpal tunnel syndrome. Each patient was 61, 56 and 24 years old. The mean follow up period was 1.5 years. ResultsAll patients experienced reduced pain postoperatively. The postoperative scar was very small (only 1 cm). There is no loss of sensation, no hematoma and no infection. ConclusionThis procedure is simple, and the postoperative morbidity for the patient is minimal. There is rapid recovery with minimal risk of complications that are associated with open techniques. Therefore endoscopic decompression for Morton neuroma offers many advantages and should be studied in a larger number of patients.

Pedal Mycetoma Mimicking Plantar Fibroma

A 47-year-old female of African origin, presented with history of a growing lump on the sole of her right foot. She normally lives in the UK, but has been visiting an African country in the last few years. Physical examination showed an isolated nodular lesion on the sole of her right foot, at the instep with intact skin, and no sinus formation. The working diagnosis was a plantar fibroma. The patient was otherwise fit and well and was not on steroids or other medications. Physical examination revealed an isolated lump on the sole of her foot, with no other findings. Differential diagnoses considered include plantar fibroma, inter-metatarsal neuroma, subcutaneous lipoma, plantar fasciitis, aspergillosis, ganglion and warts among others. She had Ultrasound and later excision biopsy followed by histology which confirmed fungal Mycetoma. She made a recovery without any additional treatment and had no recurrence after two years of follow-up.

La sindrome di Morton

Morton’s syndrome (MS) is a typical metatarsalgia, due to an intermetatarsal neuroma. Patients complain of burning pain in the lateral metatarsal region, extending into the third, fourth or both toes. Patients typically experience pain relief by sitting down, removing the shoe, and massaging the foot.The diagnosis is primarily clinical, producing pain by compression with the fingers in the second or third web-space and moving the neuroma up and down between metatarsal bones according to the Mulder’s manouvre.Other sources of forefoot pain can be misdiagnosed as an interdigital neuroma, like metatarsal stress fractures, early rheumatoid arthritis, Freiberg’s infraction, biomechanical disorders of the Mp joint. Therefore, diagnosis needs a confirmation with advanced imaging. Ultrasound (US) intermetatarsal exploration of forefoot, reproducing local pain and Mulder’s click with dynamic manoeuvres, is today, if performed by a well-experienced examinator, an easy and economical test to confirm clinical suspect, with an accuracy of about 90% for intermetatarsal masses greater than 4 mm. There are differing reports about the accuracy of diagnosis with magnetic resonance imaging (MRI), more indicated as a second level examination fot doubtful cases.As for treatment of MS, alcohol injection under sonographic guidance is today a preferred method for intermetatarsal masses greater than 4 mm. Two or three injections of 1 cc of medical alcohol 30% diluted with 70% of xylocaine 2%, injected directly in the mass, are required. In our experience of 150 published cases, success rate is about 80%, without any hindrance to surgery in case of persistent pain.Surgery is indicated in refractory cases and can be done in a formal operative suite in outpatient surgery. The dorsal intermetatarsal approach is preferred, isolating the neuroma from distal to proximal, after transverse intermetatarsal ligament transection. After careful isolation of the third common digital nerve from the thin plantarly directed branches and, if present, the accessory branch of the lateral plantar nerve, the nerve is resected with a new fifteen blade and passed through the fibers of the transverse adductor muscle (neurectomy/relocation technique) to prevent mechanical irritation in case of a stump neuroma.According to literature, results of surgery have been favorable, with 90% of success, when MS was localized in a third web space, but with a worse outcome in cases with second web space (60%) or multiple web space intervention.

Diagnosis and Treatment of Forefoot Disorders. Section 3. Morton's Intermetatarsal Neuroma

This clinical practice guideline (CPG) is based upon consensus of current clinical practice and review of the clinical literature. The guideline was developed by the Clinical Practice Guideline Forefoot Disorders Panel of the American College of Foot and Ankle Surgeons. The guideline and references annotate each node of the corresponding pathways.

Prevalence and type of foot surgery performed in Australia: A clinical review

The aim of this study was to investigate the type and prevalence of foot surgery being conducted by fellows of the Australian College of Podiatric Surgeons. Methods A clinical audit of 786 patient files was undertaken, all of whom had been operated on by 10 podiatric surgeons during a 12-month period. A coding framework was used whereby all files audited had each foot condition classified according to the International Classification of Diseases. Results A total of 1575 diagnosed conditions, which subsequently underwent surgical treatment were identified in 785 case files. The most common conditions identified in this study were: lesser toe deformities (46.1%), hallux abducto valgus (20.8%), intermetatarsal neuroma (Morton's) (7.8%), hallux rigidus/limitus (6.6%) and onychocryptosis (6.7%). It would appear that, on a state for state basis, the amount of foot surgery conducted by podiatric surgeons across Australia is relatively uniform. In terms of the type and prevalence of conditions surgically treated by podiatrists internationally, these rates bear striking similarity to the results reported in the United Kingdom and the United States. Conclusion The data suggests podiatric surgeons operate ostensibly on healthy female patients in their fifth and sixth decade of life. Almost half of the patients operated upon underwent multiple procedures, with variability in the type and frequency of procedures most likely being attributable to individual surgeon preference.

The Operational Characteristics of Ultrasonography for the Diagnosis of Plantar Intermetatarsal Neuroma

A retrospective study was carried out on 48 patients to correlate preoperative ultrasound findings with postoperative histopathology findings and to assess the sensitivity, specificity, positive predictive values, and negative predictive values of ultrasound in the diagnosis of Morton's interdigital neuroma. All case sheets of 48 patients operated on between 1997 and 2005 were reviewed in the medical record section of Ninewells Hospital, Dundee, Scotland, so that preoperative ultrasound reports were compared with the postoperative histopathological reports. A statistical analysis of the results was performed. Ultrasonography showed 43 true-positive cases, 1 true-negative case, and 4 false-negative cases out of 48 cases. Histopathology showed 47 true-positive cases and 1 true-negative case; statistical analysis performed on the results showed a sensitivity of 91.48%, a specificity of 100%, and 100% positive and 20% negative predictive values, respectively. In our analysis, the probability that ultrasound will confirm the presence of plantar intermetatarsal neuroma is 91.67%.

Minimally Invasive Morton's Intermetatarsal Neuroma Decompression

We present the results of an alternative technique for decompression of a Morton intermetatarsal neuroma that is minimally invasive and does not require endoscopic instrumentation. Seventeen nerve decompressions were performed in 14 patients using an instrument designed to release the transverse carpal ligament for carpal tunnel syndrome. Nine women and five men (3 bilateral) had the procedure performed. The mean followup for the 17 decompression procedures was 25.92 months. Eleven of the 14 patients had absence of the neuroma symptoms after the decompression. Two patients had recurrence of symptoms; the third had sustained a crush injury to the operated foot. Both patients with recurrence required revision surgery because the initial procedure failed to relieve symptoms. One patient noted lack of relief in the immediate postoperative period (2 weeks), the other was symptom free for approximately 1 year. Only one of these individuals responded to resection of the intermetatarsal nerve, while the other continues to have pain. There were no wound healing complications or complications related to digital deformity after the procedure. The technique is simple, the postoperative morbidity to the patient is minimal, and the results in this limited number of patients was encouraging.

Forefoot Complaints - the Morton's Metatarsalgia. The Role of MR Imaging.

An illustrated case with Morton's metatarsalgia is presented. MR imaging was helpful for determining the presence, location and magnitude of intermetatarsal neuroma. Moreover, it had a large influence on the differential diagnostic thinking because many disorders may produce forefoot complaints mimicking Morton's metatarsalgia.

(760): ALGRX 4975 reduces pain of intermetatarsal neuroma: Preliminary results from a randomized, double-blind, placebo-controlled, phase II multicenter clinical trial

ALGRX 4975 is capsaicin for injection. Subjects with painful intermetatarsal neuroma received a single injection of ALGRX 4975, 100 μg in 0.5 ml, or placebo, 0.5 ml, into the intermetatarsal space 10 minutes following lidocaine with epinephrine, 2 ml of 2% solution. The primary efficacy endpoint was change from baseline in the average foot pain rating scale (11 point NRS). Pain at baseline was 5.7 in both the group that subsequently received ALGRX 4975 (n=30) as well as group that received placebo (n=28). The change in pain scores at the end of weeks 1, 2, 3, and 4 was −2.1 compared to −0.6 (p=0.0205), −2.3 compared to −1.5 (p=0.1422), −2.9 compared to −1.8 (p=0.0719), and −3.5 compared to −2.1 (p=0.0188), respectively. Pain scores summed over the entire observation period were 13.0 in the group that received ALGRX 4975 compared to 17.5 in the group that received placebo (−4.5 ALGRX 4975 compared to placebo, p=0.0235). There were no statistically significant differences between the two groups in the change in averages of the seven interference items from the BPI. Injection of ALGRX 4975 was associated with transient pain on injection. A decrease in sensory perception was apparent at the injection site in both groups following injection, which returned to baseline by the end of week 4. A single injection of ALGRX 4975, 100 μg, was associated with less pain during a four week observation period in subjects with intermetatarsal neuroma compared to placebo.

Morton's Neuroma

Morton's neuroma, known also as intermetatarsal or interdigital neuroma, is a common foot injury that often curtails athletic activity. Nerve compression involving adjacent metatarsal heads and the transverse intermetatarsal ligament appears implicated in injury onset. Diagnosis is made clinically, and the condition typically causes initial symptoms of dull cramping or burning pain and more persistent sharp pain with nerve deterioration. Depending on injury severity, treatment is either conservative or surgical.

Recurrent intermetatarsal neuroma. A follow-up study.

Sixteen patients were evaluated following excision of recurrent intermetatarsal neuroma. Each underwent removal of a segment of nerve through an incision on the plantar aspect. The nerve stump was buried in the flexor digitorum brevis muscle. At the time of follow-up examinations, six patients were asymptomatic, seven experienced mild pain after extended activity, one suffered mild consistent pain with activity, and two suffered pain that limited activities.

Metatarsus proximus and digital divergence. Association with intermetatarsal neuromas

A retrospective radiologic study was performed to determine whether there is an increased finding of metatarsus proximus and digital divergence in patients with a confirmed diagnosis of intermetatarsal neuroma when compared with an asymptomatic group. The study included 48 patients with pathologic confirmation of neuroma and 100 asymptomatic patients. Results of the study revealed no statistical relationship between the radiologic findings of metatarsus proximus and digital divergence and the physical occurrence of neuromas. An unexpected finding was an increased intermetatarsal angle of the affected interspace in the neuroma group.