Plantar approach for excision of a Morton neuroma: a long-term follow-up study

Safety and Efficacy of Percutaneous Morton Neuroma Cryoneurolysis Under Ultrasound Guidance

PURPOSE

To assess the technical success, safety and early efficacy of Morton neuroma (MN) cryoneurolysis.

MATERIALS AND METHODS

Retrospective review of 54 consecutive patients with MN treated with cryoneurolysis after failure of conservative treatment, from September 2022 to June 2023. Outcomes measurements included technical success (defined a successful ultrasound-guided placement of the cryoprobe), procedural safety according to Cirse classification and change in 6 months post-procedure by pain numeric rating scale (pNRS).

RESULTS

A total of 59 MN were treated during 55 procedures. Mean procedure duration was 47 min, all patients were discharged 2 h after the intervention. Technical success was 98.1%. No Cirse grade 3, 4 or 5 complication was reported. Three grade 2 complication occurred, including two chilblain-type lesions and one bone insufficiency fracture. At 6 months post-procedure, pNRS score was significantly decreased (2.7 ± 2.2 vs 7.1 ± 1.1) (p < 0.0001), with a mean score decrease of 4.1points. Thirty-two patients (60.4%) reported a complete pain relief, 15 (28.3%) a partial pain relief and 6 (11.3%) no pain relief, or increased pain.

CONCLUSION

Cryoneurolysis seems to be safe for the treatment of Morton neuroma. Six-month pain relief is promising and needs to be confirmed at long term.

Effect of surgical approach on the treatment of Morton's neuroma: a systematic review and meta-analysis

BACKGROUND

Surgical resection of Morton's neuroma includes dorsal and plantar approaches. However, there is no consensus on the choice of approach in clinic. The purpose of this study was to conduct a systematic review and meta-analysis to compare the surgical results of dorsal and plantar approaches.

METHODS

The literatures of PubMed, Cochrane library, Embase and Web of Science were searched on April 26th, 2023. A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The data were extracted after screening the literature and evaluating the quality of the methodology included in the study. The RevMan5.4 software was used to analyze and calculate the OR value and 95% confidence interval.

RESULTS

A total of 7 randomized controlled trials and comparative studies were published, of which only 5 were included. There were 158 feet via plantar approach (plantar group, PG) and 189 via dorsal approach (dorsal group, DG). There was no significant difference between PG and DG in overall adverse events, sensory problems, incision infection and deep vein thrombosis (p > 0.05). In terms of scar problems, PG showed more than DG (OR, 2.90[95%CI, 1.40 to 5.98]; p = 0.004). Other outcome indicators such as visual analogue scale (VAS) scores and American Orthopedic Foot and Ankle Society (AOFAS) scores were difficult to be included in the comparison.

CONCLUSIONS

Based on the relatively low quality and small amount of available evidence, the meta-analysis conducted produces a hypothesis that the frequency of adverse events in surgical treatment of Morton's neuroma, dorsal approach and plantar approach may be the same, but the types are different. More high-level evidence is needed to further verify this hypothesis.

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

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

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.

Minimally invasive neurectomy for Morton's neuroma with interdigital approach. Long term results

BACKGROUND

"Morton's Neuroma" is a frequent cause of chronic forefoot pain. It can affect general population, including athletes, and can lead to progressive foot pain and discomfort for daily life activities and sports.

HYPOTHESIS/PURPOSE

Our objective is to evaluate the long-term results in a series of 85 feet, operatively treated with minimally invasive interdigital approach for neurectomy.

STUDY DESIGN

Case series.

METHOD

83 patients (85 feet) were treated between January 2003 and December 2019. The AOFAS score and VAS scale were used to evaluate the patients pre and postoperatively. Results were analyzed using the JASP software.

RESULTS

Mean age was 50.58 years (range 23-77). Eleven (11) were men, and seventy-four (74) women, with two bilateral cases. Mean follow up was 49 months. Our series was evaluated with AOFAS and VAS scores, both showing statistically significant improvement posterior to the operative procedure.

CONCLUSIONS

A series of 85 feet operatively treated for Morton's neuroma with minimally invasive interdigital approach for neurectomy is presented. Long term results were similar to other published series with different approaches, with the advantage of minimal incision, minimum soft tissue dissection and no need to release intermetatarsal ligament, immediate weightbearing and quick return to daily activities and sports. It is concluded that minimally invasive neurectomy with interdigital approach is a safe procedure for Morton's neuroma treatment with similar results that other operative procedures.

LEVEL EVIDENCE

Level IV.

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.

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.

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.

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.

Mallet Toes, Hammertoes, Neuromas, and Metatarsophalangeal Joint Instability: 40 Years of Development in Forefoot Surgery

BACKGROUND

Today's foot and ankle surgeon has an enhanced understanding of forefoot pathology and treatment options compared to surgeons who practiced in previous decades. This paper summarizes developments in forefoot surgery in the past 40 years, specifically in treatments for mallet toe, hammertoe, neuroma, and metatarsophalangeal joint instability.

MATERIALS AND METHODS

A review of the literature was conducted using the PubMed search engine, with key terms including, "mallet toe," "hammertoe," "neuroma," "metatarsophalangeal joint instability," "plantar plate," and "forefoot surgery." Chapters in major orthopaedic textbooks covering these topics were also reviewed. We then chronicled the history of the diagnosis and treatment of these pathologies, with a focus on the past 40 years.

CONCLUSIONS

There have been major advances in understanding and treating forefoot pathologies in the past four decades; however, there remain areas for improvement both in the diagnosis and treatment of these problems.

LEVEL OF EVIDENCE

Level V, meta-synthesis.

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.

Efficacy, Outcomes, and Alignment Following Isolated Fibular Sesamoidectomy via a Plantar Approach

BACKGROUND

The purpose of this study was to evaluate patients for intermediate-term pain relief, functional outcome, and changes in hallux alignment following isolated, complete fibular sesamoidectomy via a plantar approach for sesamoid-related pain recalcitrant to conservative treatment.

METHODS

A retrospective query of a tertiary referral center administrative database was performed using the Current Procedural Terminology code 28135 for sesamoidectomy between 2005 and 2016. Patients who underwent an isolated fibular sesamoidectomy were identified and contacted to return for an office visit. The primary outcome measure was change in visual analog pain score at final follow-up. Secondary measures included satisfaction, hallux flexion strength, hallux alignment, pedobarographic assessment, and postoperative functional outcome scores. Patients who met the 2-year clinical or radiographic follow-up minimum were included. Ninety fibular sesamoidectomies were identified. Thirty-six sesamoidectomies met inclusion criteria (median 60-month follow-up). The average patient was 36 years old and underwent sesamoidectomy 1.1 years after initial diagnosis.

RESULTS

Median visual analog scale scores improved 5 (6 to 1) points at final follow-up (P < .001). Final postoperative mean hallux valgus angle did not differ from preoperative values (10.5 degrees/8.5 degrees, P = .12); similarly, the intermetatarsal angle did not differ (8.0 degrees/7.9 degrees, P = .53). Eighty-eight percent of patients would have surgery again and 70% were "very satisfied" with their result. Hallux flexion strength (mean 14.7 pounds) did not differ relative to the contralateral foot (mean 16.1 pounds) (P = .23). Among the full 92 case cohort, 3 patients underwent 4 known reoperations.

CONCLUSION

Fibular sesamoidectomy effectively provided pain relief (median 5-year follow-up) for patients with sesamoid pathology without affecting hallux alignment.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

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.

Endoscopic Interdigital Neurectomy of the Foot

Morton's neuroma is a compressive neuropathy resulting in perineural fibrosis rather than a neuroma of the plantar digital nerve. Surgical treatment is indicated for patients with a clear diagnosis of Morton's neuroma and no improvement with nonsurgical treatment. The surgical options include isolated intermetatarsal ligament division, isolated interdigital nerve excision, and interdigital nerve excision with intermetatarsal ligament division, with or without submuscular transposition. This can be performed via dorsal or plantar approach. The open approaches require long incisions and extensive soft-tissue dissection. The purpose of this Technical Note is to describe the surgical details of endoscopic interdigital neurectomy. This is an endoscopic approach involving interdigital nerve excision with intermetatarsal ligament division and submuscular transposition.

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.

Excision of Morton's Neuroma Using a Longitudinal Plantar Approach: A Midterm Follow-up Study

BACKGROUND

Operative procedures are indicated in the treatment of Morton's neuroma (MN) when conservative therapies have been unsuccessful. A dorsal approach for neurolysis or neurectomy was strongly recommended. The aim of this case series study was to prospectively analyze the midterm clinical outcome and complications following the excision of a MN using a plantar longitudinal approach.

METHODS

Between September 2000 and January 2009, we included 44 patients (51 feet, 56 neuromas) in a prospective study treated by excision of a primary MN using a plantar longitudinal approach. The MN diagnosis was based on clinical symptoms, magnetic resonance imaging findings, and pain relief after infiltration of local anesthetics. Histological examinations were performed in all resected specimens. The patients returned for final follow-up at a mean of 54 (range = 12 to 99) months, comparing preoperative and postoperative perception of pain on a Visual Analogue Scale (VAS) and assessing clinical findings.

RESULTS

The average amount of pain, according to VAS, was 8 (range = 6-9) points preoperatively and 0.4 (range = 0-5) points at final follow-up. Complications occurred in 7.1% of interventions and scar problems in 5.2%, including delayed wound healing, hypertrophic scar formation, and inclusion cyst.

CONCLUSION

The present study shows a strong relief of pain after MN resection using a plantar longitudinal incision, coupled with a low rate of local complications. This surgical procedure seems to be a reliable choice for the excision of MN, even in cases with MN in adjacent webspaces, because it is technically simple and the plantar scar is not bothersome if properly located.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Prospective, Case series.

Plantar approach for Morton's neuroma: An effective technique for primary excision

BACKGROUND

Morton's neuroma is a common cause of inter-metatarsal foot pain. Surgical excision is generally indicated when non-operative measures have been unsuccessful; various surgical techniques have been described in the literature for excision, with no consensus on the overall ideal surgical approach.

AIM

To assess patient outcomes and complications following plantar surgical approach to neurectomy in a consecutive series of patients.

METHOD

An analysis of consecutive patients undergoing excision of Morton's neuroma using a plantar approach by a single surgeon over a 12 month period. Pre- and post-operative AOFAS and VAS scores were completed during outpatient visits.

RESULTS

20 patients were included in the study, with pre-operative confirmation of a soft tissue mass on ultrasound scan. All patients demonstrated improvement in their post-operative functional scores; 2 patients (10%) did not have full resolution of their symptoms post-operatively. Mean AOFAS scores improved from 39 to 80 post-operatively and VAS from 40 to 92. No patients had wound complications or scar pain.

CONCLUSION

Neurectomy performed via a plantar approach provides good exposure, adequate soft tissue healing, with rapid resolution of pain and return to normal activities post-operatively.

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.

Clinical anatomy of the ankle and foot

This paper emphasizes the anatomical substrate of several foot conditions that are seldom discussed in this context. These include the insertional and non-insertional Achilles tendinopathies, plantar fasciopathy, inferior and posterior heel spurs, foot compartment syndromes, intermetatarsal bursitis and Morton's neuroma. It is a rather superficial anatomical review of an organ that remains largely neglected by rheumatologists. It is our hope that the cases discussed and the cross examination by instructors and participants will stimulate study of the foot and the attention it deserves.

Plantar Approach for a Morton Neuroma: Surgical Technique

Introduction

The plantar approach for management of a Morton neuroma allows the transverse metatarsal ligament to be spared, decreases the risk of damage to the dorsal cutaneous nerve branches, and has a low rate of complications with results comparable with those of other approaches.

Step 1 Incision

Make a transverse plantar skin incision distal to the metatarsal weight-bearing area.

Step 2 Exposure

Excise the connective tissues around the neuroma and expose the common digital nerve as far proximally as possible.

Step 3 Resection

Identify the resection point over the metatarsal neck and cut the neural branches as proximal and as distal as possible.

Step 4 Closure

Suture the fat pad using inverting absorbable sutures and the skin using nonabsorbable monofilament sutures.

Results

We assessed 160 of 168 patients who had undergone surgical excision of a Morton neuroma; the median duration of follow-up was 7.1 years¹³.

What to Watch For

IndicationsContraindicationsPitfalls & Challenges.