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

Prospective observational analysis of intraoperative radiation exposure with a mini C-arm intensifier in percutaneous forefoot surgery

INTRODUCTION

Percutaneous forefoot surgery has been associated with higher radiation exposure than the conventional approach. However, there is little data on forefoot surgery using a mini C-arm intensifier. We, therefore, conducted a prospective study to (1) evaluate the intraoperative radiation received by the surgeon during percutaneous forefoot surgery with a mini C-arm; (2) compare the radiation received by the surgeon with the guidelines for occupational exposure issued by the International Commission on Radiological Protection (ICRP) (20 millisieverts per year [mSv/year] for the whole body, 500mSv/year for the hands, and 20mSv/year for the lens of the eye); and (3) compare the radiation received during percutaneous forefoot surgery with that of the open approach, which has already been reported in the literature.

HYPOTHESIS

The radiation received by the surgeon during percutaneous forefoot surgery with a mini C-arm is lower than the ICRP guidelines, and the findings reported in the literature.

MATERIALS AND METHODS

This prospective single-center study was conducted from September 2020 to May 2021. A total of 639 feet (i.e., 435 patients) were included. Of these 639 feet, 336 (52%) were hallux valgus repairs, 49 (8%) were stand-alone procedures of the lateral rays, and 124 (19%) were a combination of both. The radiation dose data was retrieved from the mini C-arm daily: dose-area product (DAP) in centigray per square centimeter (cGy/cm2) and radiation exposure duration in seconds. The doses received by the surgeon were collected every month by 4 passive dosimeters (hand, eye lens, and chest [on and under the lead apron]) and 2 active dosimeters (on and under the lead apron).

RESULTS

The DAP emitted by the mini C-arm during an operating day was 0.10±0.01cGy/cm2 (range, 0.0-3.9), and the mean daily radiation duration was 34.7±19.3seconds (range, 0.7-226.8). There was a mean of 8±8 (range, 1-18) elective procedures per operating day. The daily reading on the active dosimeter worn on the lead apron was 0.002±0 microSv (range, 0-0.04), while the one worn under the apron was 0.001±0 microSv (range, 0-0.03). The equivalent doses over the 7-month study period for the hand, eye lens, and chest (over and under the apron) were 0.14mSv, 0mSv, 0.22mSv, and 0mSv, respectively.

DISCUSSION/CONCLUSION

The radiation exposure in percutaneous forefoot surgery with a mini C-arm intensifier observed in our study was lower than the ICRP recommendations and literature findings during open surgery.

LEVEL OF EVIDENCE

IV; prospective study without a control group.

Metatarsal sliding osteotomy is effective without altering plantar pressure in Morton's neuroma: Retrospective case series

BACKGROUND

Various operative methods for the treatment of Morton's neuroma have been discussed, and osteotomy of the metatarsal bone has been reported recently. However, there has been no report of pedobarographic changes after metatarsal osteotomy. Pedobarographic changes of other metatarsal area after the surgery may cause transfer metatarsalgia, and thorough analysis of the pedobarographic data should be performed peri-operatively. The purpose of this study is to investigate the post-operative pedobarographic changes of sliding osteotomy of the 3rd metatarsal bone for treating Morton's neuroma.

METHODS

Forty patients (45 feet) who underwent metatarsal sliding osteotomy of the 3rd metatarsal bone for treating Morton's neuroma from November 2013 to December 2021 were retrospectively reviewed. Proximal sliding osteotomy was performed at the proximal 3rd metatarsal bone through dorsal approach. Clinical outcomes were evaluated with American Orthopaedic Foot and Ankle Society Lesser Metatarsophalangeal Interphalangeal Scale (AOFAS LMIS), Foot Function Index (FFI), and Visual Analogue Scale (VAS). Plain radiograph and pedobarogram were performed to evaluate the radiologic and pedobarographic outcomes.

RESULTS

AOFAS score was improved from 52.8 ± 9.0 (18-62) to 88.8 ± 9.8 (78-100) and FFI was improved from 61.8 ± 4.9 (50-70) to 32.2 ± 5.1 (23-42) on average. The 3rd metatarsal bone was shortened by 3.1 ± 0.8 mm and dorsally shifted by 1.5 ± 0.4 mm after the surgery. Plantar intermetatarsal distances between 2nd and 3rd and 3rd and 4th metatarsal heads were significantly increased post-operatively. Average forefoot pressure and maximum pressure of the 2nd to 4th metatarsal head were not significantly changed between pre-operatively and post-operatively.

CONCLUSION

Proximal metatarsal sliding osteotomy of the 3rd metatarsal bone shows a satisfactory result in both clinical and pedobarographical evaluations. It could be an effective treatment of permanent indirect decompression of Morton's neuroma with avoiding recurred neuroma, adhesion of tissue, paresthesia, and transfer metatarsalgia.

Nerve entrapment syndromes of the lower limb: a pictorial review

Peripheral nerves of the lower limb may become entrapped at various points during their anatomical course. While clinical assessment and nerve conduction studies are the mainstay of diagnosis, there are multiple imaging options, specifically ultrasound and magnetic resonance imaging (MRI), which offer important information about the potential cause and location of nerve entrapment that can help guide management. This article overviews the anatomical course of various lower limb nerves, including the sciatic nerve, tibial nerve, medial plantar nerve, lateral plantar nerve, digital nerves, common peroneal nerve, deep peroneal nerve, superficial peroneal nerve, sural nerve, obturator nerve, lateral femoral cutaneous nerve and femoral nerve. The common locations and causes of entrapments for each of the nerves are explained. Common ultrasound and MRI findings of nerve entrapments, direct and indirect, are described, and various examples of the more commonly observed cases of lower limb nerve entrapments are provided.Critical relevance statement This article describes the common sites of lower limb nerve entrapments and their imaging features. It equips radiologists with the knowledge needed to approach the assessment of entrapment neuropathies, which are a critically important cause of pain and functional impairment.Key points• Ultrasound and MRI are commonly used to investigate nerve entrapment syndromes.• Ultrasound findings include nerve hypo-echogenicity, calibre changes and the sonographic Tinel's sign.• MRI findings include increased nerve T2 signal, muscle atrophy and denervation oedema.• Imaging can reveal causative lesions, including scarring, masses and anatomical variants.

[Minimally invasive forefoot surgery: concept and techniques]

Minimally invasive surgery (MIS) has advanced to an established approach in the correction of all deformities of the forefoot. For the first ray the minimally invasive chevron and Akin osteotomy (MICA) shows very good clinical results and provides a broad spectrum of indications in comparison to the classical chevron osteotomy. The minimally invasive treatment of hallux rigidus also seems to achieve comparable results to the open techniques, although the surgical indications must be thoroughly evaluated. Lesser toe deformities are often easier to treat with minimally invasive osteotomy, capsule release and tendon lengthening than with complex open procedures and usually do not require any internal fixation material. Compared to the classical Weil osteotomy, distal metatarsal osteotomy shows a reduced rate of cock-up deformities and does not require internal fixation. In relation to open procedures, minimally invasive approaches should be accepted as a valuable addition and alternative to the classical open techniques due to the reduced rate of wound healing disorders and postoperative pain.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Percutaneus intermetatarsal ligament release and minimally invasive distal metatarsal osteotomy for treatment second intermetatarsal space syndrome

BACKGROUND AND OBJECTIVE

Since the description of the syndrome of the second intermetatarsal space, this is a common diagnosis among foot and ankle surgeons. However, no series have been published that consider this syndrome as its own entity. The objective of this study is to evaluate the clinical and radiological results of the release of the intermetatarsal ligament and minimally invasive distal metatarsal osteotomy in patients diagnosed with second space syndrome.

MATERIALS AND METHODS

An observational, longitudinal, retrospective study was carried out in patients with a clinical diagnosis of second space syndrome operated on using a minimally invasive technique. For the clinical results, the visual analog scale (VAS) for subjective pain, the Manchester-Oxford Foot Questionnaire (MOXFQ) and the scale for minor metatarsals and interphalangeals of the American Orthopedic Foot and Ankle Society (AOFAS-LMTS) were used for clinical-functional assessment. Consolidation or not of osteotomies was recorded and complications were recorded.

RESULTS

Twenty-nine feet in 29 patients were included in the study. After a mean follow-up of 39 months (25-50), clinically and statistically significant improvement was obtained in the scores: pain VAS, scales and subscales of the MOXFQ and the AOFAS-LMTS (p < 0.0001). All osteotomies healed at the end of follow-up and no major complications were recorded.

CONCLUSIONS

Percutaneous or minimally invasive surgery, in patients with second intermetatarsal space syndrome, obtains good clinical, functional and subjective results, with few complications. Therefore, we consider it an effective, safe and recommended technique in the hands of experienced surgeons.

Intermetatarsal ligament section assisted with sonography for the percutaneous surgery of Morton's disease: Cadaveric study

BACKGROUND

Surgical treatment of Morton's neuroma remains controversial. Several surgical techniques have been described including percutaneous transection of the deep metatarsal transverse ligament (DMTL).

PURPOSE

To evaluate the efficacy and safety of percutaneous release of the DMTL under ultrasound guidance for the treatment of Morton's syndrome.

MATERIALS AND METHODOLOGY

Percutaneous release of the DMTL was performed with ultrasound guidance in 48 intermetatarsal spaces of 16 cadaveric specimens. Specimens were then dissected to assess the completion of the release and the presence of any injuries of the neurovascular and tendinous adjacent structures.

RESULTS

The DMTL was visualized with ultrasound in all cases. Complete release of the ligament was achieved in 87.5% (42/48) cases. One case of interdigital nerve injury was found.

CONCLUSION

Percutaneous release of DMTL with ultrasound guidance for the treatment of Morton's disease has an acceptable rate of complications but care must be taken to ensure the complete release of the ligament.

Isolated Intermetatarsal Ligament Release as Primary Operative Management for Morton's Neuroma: Short-term Results

BACKGROUND

Although the precise pathoetiology of Morton's neuroma remains unclear, chronic nerve entrapment from the overlying intermetatarsal ligament (IML) may play a role. Traditional operative management entails neuroma excision but risks unpredictable formation of stump neuroma.

MATERIALS AND METHODS

Medical records were examined for adult patients who failed at least 3 months of conservative treatment for symptomatic and recalcitrant Morton's neuroma and who then underwent isolated IML decompression without neuroma resection.

RESULTS

A total of 12 patients underwent isolated IML decompression for Morton's neuroma with an average follow-up of 13.5 months. Visual Analog Pain Scale averaged 6.4 ± 1.8 (4-9) preoperatively and decreased to an average of 2 ± 2.1 (0-7) at final follow-up (P = .002). All patients reported significant improvement.

CONCLUSION

Isolated IML release of chronically symptomatic Morton's neuroma shows promising short-term results regarding pain relief, with no demonstrated risk of recurrent neuroma formation, permanent numbness, or postoperative symptom exacerbation.

LEVEL OF EVIDENCE

Level IV: Case series.

Operative treatment options for Morton's neuroma other than neurectomy - a systematic review

BACKGROUND

The effectiveness of operative treatments other than neurectomy for Morton's neuroma remains debatable despite several reported studies. This review aimed to evaluate the effects of operative treatments for Morton's neuroma other than neurectomy using an algorithmic approach and a structured critical framework to assess the methodological quality of reported studies.

METHODS

Several electronic databases were searched for articles published until August 2021 that evaluated the outcomes of operative treatments other than neurectomy in patients diagnosed with Morton's neuroma. Data searches, extraction, analysis, and quality assessments were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and the clinical outcomes were evaluated using objective, subjective, and negative outcomes; complications; and reoperation rate and type.

RESULTS

After reviewing 11,213 studies, 22 studies were finally included. Although a number of studies with high level of evidence are limited, we divided them according to four categories: (1) neurolysis with or without nerve transposition, (2) minimally invasive nerve decompression, (3) metatarsal osteotomy, and (4) additional procedures after nerve transection or neurectomy. All categories showed reliable outcomes except minimally invasive nerve decompression. The proportion of postoperative neurogenic symptoms was lower with neurolysis than with neurectomy.

CONCLUSION

Whether the alternative procedures were superior to neurectomy remains unclear as the number of good quality studies was limited. The proportion of postoperative neurogenic symptoms was lower with neurolysis than with neurectomy. Furthermore, performing simultaneous dorsal transposition of the nerve along with neurolysis is more recommended than neurolysis alone. Surgeons should be more careful with minimally invasive deep transverse intermetatarsal ligament release and metatarsal shortening osteotomy as their effectiveness remains inconclusive. Finally, we strongly recommend performing intramuscular embedding or intermuscular transposition of the nerve cutting end if neurectomy or nerve transection is inevitable.

LEVEL OF EVIDENCE

Level III, systematic review.

"The Feasibility of Targeted Muscle Reinnervation for the Management of Morton's Neuroma"

BACKGROUND

Despite multiple surgical modalities available for the management of Morton's neuroma, complications remain common. Targeted muscle reinnervation (TMR) has yet to be explored as an option for the prevention of recurrence of Morton's neuroma. The purpose of the present investigation was to determine the consistency of the relevant foot neurovascular and muscle anatomy and to demonstrate the feasibility of TMR as an option for Morton's neuroma.

METHODS

The anatomy of 5 fresh-tissue donor cadaver feet was studied, including the course and location of the medial and lateral plantar nerves (MPNs and LPNs), motor branches to abductor hallucis (AH) and flexor digitorum brevis (FDB), as well as the course of sensory plantar digital nerves. Measurements for the locations of the muscular and sensory branches were taken relative to landmarks including the navicular tuberosity (NT), AH, FDB, and the third metatarsophalangeal joint (third MTPJ).

RESULTS

The mean number of nerve branches to FDB identified was 2. These branch points occurred at an average of 8.6 cm down the MPN or LPN, 9.0 cm from the third MTPJ, 3.0 cm distal to AH distal edge, and 4.8 cm from the NT. The mean number of nerves to AH was 2.2. These branch points occurred at an average of 6.3 cm down the MPN, 11.9 cm from the third MTPJ, 0.8 cm from the AH distal edge, and 3.8 cm from the NT.

CONCLUSIONS

Recurrent interdigital neuroma, painful scar, and neuropathic pain are common complications of operative management for Morton's neuroma. Targeted muscle reinnervation is a technique that has demonstrated efficacy for the prevention and treatment of neuroma, neuropathic pain, and phantom limb pain in amputees. Herein, we have described the neuromuscular anatomy for the application of TMR for the management of Morton's neuroma. Target muscles, including the AH and FDB, have consistent innervation patterns in the foot, and consequently, TMR represents a viable option to consider for the management of recalcitrant Morton's neuroma.

LEVELS OF EVIDENCE

V.

Ultrasound-guided Injection Treatments versus Surgical Neurectomy for Morton Neuroma: A Cost-effectiveness Analysis

Background: Morton neuroma is a common, painful disorder of the foot with multiple treatment options of varying cost and effectiveness. Objective: The aim of this study was to determine the most cost-effective treatment pathway for symptomatic Morton neuromas that have failed conservative management. Methods: An incremental cost-utility analysis was performed comparing a direct to surgical neurectomy strategy with three injection selective strategies in which one or more ultrasound-guided injection therapies was tried first prior to surgery for non-responders. The three injection selective strategies included: (1) steroid selective (2) alcohol selective, and (3) steroid/alcohol selective in which both steroid injections and alcohol sclerosing injections were trialed successively prior to surgical neurectomy. The direct to surgery approach was compared with the three different injection selective strategies, and with a no-treatment strategy, in a decision-analytic model for a hypothetical group of patients with symptomatic Morton neuromas that had failed conservative management. Model parameters including treatment costs, effectiveness, complication rates, and health utility states were estimated from the literature, reimbursement databases, and expert opinion. The outcome was cost per quality adjusted life year (QALY) with a time horizon of three years. A societal cost perspective was adopted with a willingness to pay threshold of $100,000 per QALY. Sensitivity analyses for key model parameters were performed. Results: For the base input values, the steroid/alcohol selective strategy was dominant and yielded an incremental cost-effectiveness ratio of $4401/QALY compared to no treatment. The probabilistic sensitivity analysis supported this strategy in 74% of 10,000 simulated trials. Results were robust with low sensitivity to most input parameters. However, when the probability of successful alcohol injection treatment dropped below 40%, the steroid selective strategy became most cost-effective. Conclusion: A trial of ultrasound-guided injection therapies for Morton neuroma is a cost-effective strategy compared to proceeding directly to surgical neurectomy. Clinical Impact: Ultrasound-guided injection therapies are indicated as a first line treatment for patients with symptomatic Morton neuromas that have failed conservative management.

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

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

Revision of Recurrent Neuromas

Forefoot neuromas are a common pathology that is seen in a wide variety of patients. Although conservative treatment is successful with modification of shoes/inserts or injections, surgical intervention is occasionally needed to alleviate the discomfort. Most surgical procedures for neuromas have a good outcome. There are times when the outcome is not optimal and revision surgery may be needed. This article describes revision surgery techniques that may lead to an improved outcome. Also discussed is the opportunity to reduce recurrence through the understanding of neuroma biology, diagnosis, and treatment options.

MIS Distal Metatarsal Metaphyseal Osteotomy in the treatment of metatarsalgia: MOXFQ patient reported outcomes

INTRODUCTION

The aim of this paper is to present validated patient reported outcomes for MIS Distal Metatarsal Metaphyseal Osteotomy (DMMO) in the treatment of metatarsalgia. The study aims to evaluate the DMMO procedure, report patient satisfaction with the operated foot and report any complications of this procedure.

PATIENTS AND METHODS

Between 2014 and 2016, patients who had failed conservative treatment for metatarsalgia were identified in the orthopaedic outpatient clinic. Twenty four consecutive patients requiring DMMO plus/minus toe straightening were prospectively studied. Patients requiring additional procedures at the time of surgery were excluded. Patients completed the validated Manchester-Oxford Foot Questionnaire (MOXFQ) three weeks pre-operatively and 1 year postoperatively. The MOXFQ results were analysed using Paired t-tests. A supplementary question was asked regarding patient satisfaction with the operated foot.

RESULTS

There were 20 women and 4 men with a mean age of 64 years (sd 8.6). Statistically significant differences were found between the pre and postoperative MOXFQ. The postoperative MOXFQ score demonstrated a poorer result for two patients, no change for two patients and improvement in 20 patients, with four of these patients recording the lowest possible score. There was a 29.5 point improvement in mean metric MOXFQ Index score. Seventy-nine percent (n = 19) of patients were satisfied or very satisfied with the operated foot. The average recoil of the metatarsal heads following DMMO was M2 4.01 mm, M3 4.55 mm, M4 4.16 mm. There was one delayed union and no non-unions. Further reported complications were a gastric bleed, pulmonary embolism (VTE), and one intra operative broken burr.

CONCLUSION

Our study demonstrates a clinically important and statistically significant improvement in patient reported outcomes following DMMO, with 79% of patients satisfied or very satisfied with this procedure. The average recoil of the metatarsal heads following DMMO was M2 4.01 mm, M3 4.55 mm, M4 4.16 mm with one delayed union and no non-unions.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Preliminary Experience With a Minimally Invasive Technique for Hallux Valgus Correction With No Fixation

BACKGROUND

Percutaneous operative techniques for hallux valgus (HV) correction are less damaging to soft tissues and the first metatarsophalangeal joint, and they carry a lower risk of wound complications. We report our preliminary results using a percutaneous technique that allowed correction of the deformity without internal fixation.

METHODS

One hundred ninety-five consecutive patients with isolated symptomatic HV were surgically treated using a percutaneous technique without any form of internal fixation, with a mean follow-up of 34.6 months. The American Orthopaedic Foot & Ankle Society (AOFAS) hallux-metatarsophalangeal-interphalangeal scale score was used for clinical assessment. Radiographic evaluation included pre- and postoperative assessment of the hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), and sesamoid position in weightbearing radiographs.

RESULTS

According to the AOFAS score, the patients improved from a preoperative median of 54.7 to 89.6 at 2 years' follow-up (P = .002). Patients were satisfied or very satisfied in 94% of cases at the latest follow-up. A mean radiographic correction of the HVA of 15.5 degrees, of the IMA of 5.4 degrees, and of the DMAA of 5.4 degrees was achieved. The AOFAS global score and every individual parameter improved significantly between pretreatment and latest follow-up (P > .01). A total of 19 (9.7%) complications were reported.

CONCLUSION

This percutaneous technique, which did not use any form of internal fixation described, produced durable results for the correction of HV, reliably correcting the deformity and resulting in significant improvement in function and decrease of pain.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

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

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

Morton's interdigital neuroma: instructional review

The terminology ‘Morton’s neuroma’ may represent a simplification of the clinical condition as the problem may not be a benign tumour of the nerve, but neuropathic foot pain associated with the interdigital nerve.

Foot and ankle pathomechanics leading to metatarsalgia, clinical examination and differential diagnosis of the condition and imaging of the condition, for differential diagnosis, are discussed.

Nonoperative management is recommended initially. Physiotherapy, injections (local anaesthetic, steroid, alcohol), cryotherapy, radiofrequency ablation and shockwave therapy are discussed.

Operative treatment is indicated after nonoperative management has failed. Neuroma excision has been reported to have good to excellent results in 80% of patients, but gastrocnemius release and osteotomies should be considered so as to address concomitant problems.

Key factors in the success of surgery are correct diagnosis with recognition of all elements of the problem and optimal surgical technique.

Cite this article: EFORT Open Rev 2019;4:14-24. DOI: 10.1302/2058-5241.4.180025.

Treatment of Morton's neuroma: A systematic review

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

Radiographic Analysis of Feet With and Without Morton's Neuroma

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level III, case control study.

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

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

Ultrasound Evaluation of Morton Neuroma Before and After Laser Therapy

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Minimally Invasive Forefoot Surgery in France

Study groups have been formed in France to advance the use of minimally invasive surgery. These techniques are becoming more frequently used and the technique nuances are continuing to evolve. The objective of this article was to advance the awareness of the current trends in minimally invasive surgery for common diseases of the forefoot. The percutaneous surgery at the forefoot is less developed at this time, but also will be discussed.

Percutaneous needling of Morton's complex: a technical note

BACKGROUND

the Morton's complex, i.e. fibrotic mass enfolding the medial plantar nerve, the bursa and the interdigital transverse ligament in the web space, is a common cause of pain and functional disability. Conservative and operative treatments are investigated but currently the best approach to treat the Morton's complex is unknown.

METHODS

we describe a non-invasive, straight forward intervention consisting on multiple percutaneous punctures, shearing the fibrotic tissue in lateromedial and anteroposterior directions. The goal is to break up fibrosis occupying the intermetatarsal space thus releasing the affected nerve from the adjacent structures, there by stimulating tissue remodelling.

RESULTS

slow tissue remodelling occurs following sequential fibrosis cleavage through multiple needling. Needling of the intermetatarsal fibrosis is performed every eight weeks until pain resolution. Echographic changes are associated to pain reduction as measured by Visual Analogue Score (VAS).

CONCLUSION

we present an original idea that may improve Morton's management. Upcoming prospective clinical studies have to demonstrate the symptomatic benefits and the usefulness of this novel echographic intervention.

The role of fasciae in Civinini-Morton's syndrome

This study evaluates the pathogenetic role of the perineural connective tissue and foot fasciae in Civinini-Morton's neuroma. Eleven feet (seven male, four female; mean age: 70.9 years) were dissected to analyse the anatomy of inter-metatarsal space, particularly the dorsal and plantar fasciae and metatarsal transverse ligament (DMTL). The macrosections were prepared for microscopic analysis. Ten Civinini-Morton neuromas obtained from surgery were also analysed. Magnetic resonance images (MRIs) from 40 patients and 29 controls were compared. Dissections showed that the width of the inter-metatarsal space is established by two fibrous structures: the dorsal foot fascia and the DMTL, which, together, connect the metatarsal bones and resist their splaying. Interosseous muscles spread out into the dorsal fascia of the foot, defining its basal tension. The common digital plantar nerve (CDPN) is encased in concentric layers of fibrous and loose connective tissue, continuous with the vascular sheath and deep foot fascia. Outside this sheath, fibroelastic septa, from DMTL to plantar fascia, and little fat lobules are present, further protecting the nerve against compressive stress. The MRI study revealed high inter-individual variability in the forefoot structures, although only the thickness of the dorsal fascia represented a statistically significant difference between cases and controls. It was hypothesized that alterations in foot support and altered biomechanics act on the interosseous muscles, increasing the stiffness of the dorsal fascia, particularly at the points where these muscles are inserted. Chronic rigidity of this fascia increases the stiffness of the inter-metatarsal space, leading to entrapment of the CDPN.