Interdigital Neuroma Research Articles

MRI of Metatarsal Head Subchondral Fractures in Patients with Forefoot Pain

The purpose of our study was to determine the MRI features of metatarsal head subchondral fractures in symptomatic adults. A retrospective review of foot MRI procedures was performed to detect cases of metatarsal head subchondral fractures over a 6-year period. MR images of selected cases were analyzed by two reviewers for the presence of subchondral fracture, marrow edema-like pattern, metatarsal head flattening, and subchondral sclerosis. Patients with a history of foot surgery, infection, or inflammatory arthritis were excluded. Assessment for coexisting osseous and soft-tissue abnormalities was also performed. Subchondral fractures of the metatarsal heads were seen in 14 patients. All patients were women. The metatarsal head most commonly affected was the second (71%, 10/14) and the dorsal third of the metatarsal articular surface was involved in 79% (11/14). MRI findings of subchondral fracture of the metatarsal head with severe marrow edema-like pattern were seen in 71% (10/14), suggesting early stage changes. Metatarsal head collapse with subchondral sclerosis and mild or absent marrow edema-like pattern were seen in 29% (4/14) indicating late-stage changes. Concurrent abnormalities included three patients (21%) with metatarsal shaft fractures and one patient (7%) with an interdigital neuroma. One subject was treated surgically. Subchondral fractures of the metatarsal heads can be detected on MR examinations of adults with forefoot pain. A subchondral fracture with associated marrow edema-like pattern is the most common presentation and likely reflects early stages of metatarsal head infraction.

An Anatomical Study of Morton's Interdigital Neuroma: The Relationship Between the Occurring Site and the Deep Transverse Metatarsal Ligament (DTML)

Using clinical and cadaver studies, we examined the relationship between the location of Morton interdigital neuromas and the surrounding structures, including the deep transverse metatarsal ligament (DTML), which has been suspected as a major causative factor in neuroma formation. Seventeen fresh-frozen cadavers were evaluated to determine the relationship between the location of Morton interdigital neuromas and the DTML at two phases of the gait cycle with 60 degrees of metatarsophalangeal dorsiflexion and with 15 degrees of ankle dorsiflexion. We measured the distance from the bifurcation of the common digital nerve in the foot to the anterior margin of the DTML and also measured the length of the DTML itself. Clinically, we checked the location of the Morton interdigital neuroma and its length during surgery in 32 feet. In the second and third webspace, the mean distance from the bifurcation of the common digital nerve of the foot to the anterior margin of the DTML was 16.7 mm, 15.1 mm in the mid-stance position, and 15.9 mm and 14.6 mm in the heel-off position. The length of the second and third DTML averaged 12.8 mm and 10.6 mm. Clinically, all of the cases of Morton interdigital neuroma started at the bifurcation area of the common digital nerve, and the mean neuroma length was 7.5 mm (6 to 11). Morton interdigital neuromas were located more distally than the DTML in both the mid-stance and the heel-off stage during walking. The main lesion was located between the metatarsal head and the metatarsophalangeal joint and more distal than the DTML, questioning previous studies suggesting that the DTML is the major causative factor in development of Morton interdigital neuroma.

Métatarsalgie de Thomas George Morton

Plantar interdigital neuroma, also called Morton neuroma, neuralgia, or metatarsalgia, is a perineural fibrosis that induces severe intermittent pain and paresthesia, most frequently between the third and fourth metatarsal heads. This compression syndrome or entrapment neuropathy involves one branch of the common plantar digital nerves. Diagnosis is based essentially on clinical examination. Imaging techniques may be useful in the diagnosis of atypical cases and postoperative recurrences. In most case, conservative treatment (such as orthotic shoes or devices or injections) is successful. When they do not succeed, surgery (neurolysis, neurectomy) may be considered.

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%.

Ultrasound-guided Interdigital Neuroma Injections: Short-term Clinical Outcomes after a Single Percutaneous Injection—Preliminary Results

To describe the procedure of ultrasound-guided Morton's neuroma and recurrent stump neuroma injections and early clinical outcomes after a single injection. Retrospective review of 44 percutaneous ultrasound-guided neuroma injections in 24 patients who had completed clinical outcomes questionnaires. A 10-point pain scale [scale of 1 (no pain) to 10 (severe pain)] in a 7-day pain log format was distributed to patients at the time percutaneous neuroma injection was performed. Neuromas were clearly visualized with sonography as hypoechoic nodules and were distinguishable from other causes of forefoot pain, such as metatarsophalangeal joint synovitis and intermetatarsal bursae. The sizes of the neuromas injected ranged between 4 and 19 mm. Postinjection, all neuromas displayed increased echogenicity and/or the appearance of fluid surrounding it, confirming localization of the therapeutic mixture. We arbitrarily subdivided the pain ratings into symptomatic (greater than 4) and asymptomatic (less than or equal to 4) for statistical analysis. Average pain level pre injection was 5.2 and average pain level was 3.7 at 7 days post single injection, with 62% of the initially symptomatic patients asymptomatic on day 7 (p < 0.000001). Overall, 76% of the total number of neuromas injected once were asymptomatic on day 7. Ultrasound can be used to accurately target Morton's neuromas and, therefore, appropriately direct therapeutic interventions, with good short-term clinical results.

Hydrocortisone/local anaesthetic injection versus ultrasound in the diagnosis of interdigital neuroma

Abstract It is generally accepted that an interdigital neuroma (Morton's neuroma) is a clinical diagnosis. If the diagnosis is equivocal, other investigations such as ultrasound (US), MRI Scan, a local anaesthetic with or without hydrocortisone or electromyographic nerve conduction studies can be used. The aim of this retrospective study is to compare the accuracy of ultrasound versus a cocktail of hydrocortisone (HCI)/local anaesthetic injection (LAI), as an adjuvant investigation in the diagnosis of interdigital neuroma. The results showed that both these investigations are excellent in confirming an interdigital neuroma.

Anatomical study of the communicating branches between the medial and lateral plantar nerves

The plantar areas of the foot have specific biomechanical characteristics and play a distinct role in balance and standing. For the forefoot surgeon, knowledge of the variations in the anatomy of communicating branches is important for plantar reconstruction, local injection therapy and an excision of interdigital neuroma. The anatomy of the communicating branches of the plantar nerves between the fourth and third common plantar digital nerves in the foot were studied in 50 adult men cadaveric feet. A communicating branch was present between the third and fourth intermetatarsal spaces nerves in all eight left feet and in six right feet (overall, 28%), and absent in 36 (72%). A communicating branch was found in 14 ft. Ten of the 14 communications were from the lateral to the medial plantar nerve. The length of the communicating branch ranged from 8 to 56 mm (average 16.4 mm) and its diameter was 0.2-0.6 times of the fourth common plantar digital nerve. The angle of the communicating branch with the common plantar digital nerve from which it originated was less than 30 degrees in 11 ft, 30-59 degrees in 27 ft, 60-80 degrees in 8 ft, and more than 80 degrees in 4 ft. Classification of the branch is based on the branching pattern of the communicating branch and explains variations in plantar sensory innervations. We think that the perpendicular coursing communicating branch is at higher risk to be severed during surgery.

Second MTP Joint Capsular Instability With Clawing Deformity: Metatarsal Osteotomy, Flexor Transfer with Biotenodesis, Hammer Toe Repair, and MTP Arthroplasty Without the Need for Plantar Incisions

Capsular instability of the second metatarsophalangeal (MTP) joint (crossover second toe deformity) is a common source of forefoot pain and often but is not always associated with deformity. Various methods of surgical treatment have been described, each with its own success and limitations. A biomechanical approach to stabilization of the second metatarsophalangeal joint often includes a flexor tendon transfer, and the results of treatment with this method have been well documented. Persistent pain after stabilization in a patient without inflammatory arthritis may be indicative of concurrent interdigital neuroma, persistent joint-related symptoms, residual tenderness related to the plantar incisions, or a combination. When the deformity is obvious (fixed clawing or hammering, MTP subluxation, and tender plantar callous), a combination of procedures is considered to provide relief of symptoms and realignment of the joint and digit. The purpose of this paper is to describe a rational approach to treatment based on the deformity while minimizing potentially painful incisions and dissection. A combination of second metatarsal capital oblique osteotomy, MTP joint arthroplasty with extensor lengthening and ligamentous/capsular repair, open hammer-toe repair, and flexor tendon transfer with biotenodesis screw fixation in the proximal phalanx is described.

Ultrasound scan for the diagnosis of interdigital neuroma

A total of 117 patients with suspected interdigital neuroma (IDN) were investigated with ultrasound scan and 90 (68%) IDN cases were demonstrated. From this group, histological analysis confirmed that 88 cases (98%) were IDN. Three cases with persistent symptoms despite a negative ultrasound scan were surgically explored and two cases had histological confirmation of an IDN. The sensitivity of ultrasound scan in the diagnosis of IDN was 98% and its specificity was 95%. The most common anatomical site was the third interspace (80%). There were a higher proportion of females diagnosed with this condition. Ultrasound appears to be an accurate and effective technique in diagnosing and localizing an IDN when applied as an adjunct to clinical symptoms and signs in cases of metatarsalgia.

Evaluation of Morton's theory of second metatarsal hypertrophy.

Originally introduced by Morton, the concept of hypertrophy of the medial cortex and the entire shaft of the second metatarsal as an objective sign of increased mobility of the first ray has not been subjected to much scrutiny. The goal of the current study was to assess the clinical relevance and reliability of radiographic measures of hypertrophy of the second metatarsal in relation to mobility of the first ray, pes planus, and tightness of the gastrocnemiussoleus in both control subjects and patients with diagnosed disorders of the forefoot. Four study groups of forty-three subjects each were evaluated. The cohort included an asymptomatic control group as well as three groups made up of patients with symptoms and a diagnosis of hallux valgus, hallux rigidus, or interdigital neuroma. Mobility of the first ray (as measured with a device and method described by Klaue et al.), arch height, and ankle dorsiflexion were measured on physical examination. Plain weight-bearing radiographs and previously established equations were used to determine hypertrophy and the length of the second metatarsal, and the hallux valgus and first-second intermetatarsal angles were measured on plain radiographs as well. There was no significant difference between the control and symptomatic groups with regard to the values for hypertrophy of the second metatarsal. The patients with hallux valgus deformity had significantly greater mobility of the first ray (p < 0.001) compared with the controls. No correlation was found between values for hypertrophy of the second metatarsal and mobility of the first ray, the length of the first metatarsal, pes planus, or restricted ankle dorsiflexion. No correlation was found between mobility of the first ray and either pes planus or restricted ankle dorsiflexion. A weak correlation (r = 0.4) was noted between increased mobility of the first ray and the hallux valgus angle. Our findings do not support Morton's concept that medial cortical hypertrophy and increased shaft width of the second metatarsal are associated with increased mobility of the first ray or relative shortness of the first metatarsal. In addition, hypertrophy of the second metatarsal was not associated with either pes planus or restricted ankle dorsiflexion. We found the practice of using hypertrophy of the second metatarsal as an indicator of mobility of the first ray to be unreliable, and thus we consider it to be an inappropriate indication for arthrodesis of the first metatarsocuneiform joint in the treatment of hallux valgus deformity.

Interdigital neuroma: clinical examination and histopathologic results in 63 cases treated with excision.

Between November 1993 and September 1999, 60 patients (three bilateral) were consecutively treated with excision of interdigital neuroma. The clinical examination was preoperatively performed and a personal interview, physical examination, and routine radiographs were included. A specific clinical rating system was developed. The clinical results were excellent or good in 49 (78%) feet, fair in 12 (19%), and poor in two (3%). Prior to surgery, the clinical evaluation score was an average of 16 points. Postoperative average score was 67 points, with an average improvement of 50 points. Histopathologically, intraneural fibrosis and sclerohyalinosis were observed, as in the interstitium; furthermore, an increase of the elastic fibers in the stroma was also observed. The precise etiology of interdigital neuroma remains obscure.

Treatment of recurrence of symptoms after excision of an interdigital neuroma

During a six-year period (January 1996 to January 2002), we re-explored 60 interspaces (49 patients, 49 feet) for recurrence or persistent symptoms after one or more previous procedures for excision of an interdigital neuroma. Ten patients underwent concomitant excision of a primary neuroma from an adjacent interspace, and 19 underwent concomitant forefoot surgery. The mean follow-up was 39.7 months (6 to 79). Evaluation included review of records and radiographs, clinical assessment, and a questionnaire regarding satisfaction, pain, restriction of footwear and activity. In total, 15 patients (30.7%) were completely satisfied, 13 (26.5%) were satisfied with minor reservations, ten (20.4%) were satisfied with major reservations and 11 (22.4%) were dissatisfied with the outcome. Of the 49 patients, 28 (57.2%) had no or mild pain, 29 (59.2%) had moderate or severe restriction of footwear and eight (16.3%) had moderate restriction of activity. Intra-operative findings, simultaneous surgery to adjacent interspaces, concomitant forefoot surgery and previous re-explorations did not significantly influence the outcome. Persistent or recurrent symptoms after transection of a nerve present a challenging problem for both the surgeon and patient. It is essential that there is a thorough pre-operative discussion with the patient, providing the rates of failure and the increased likelihood of restriction of footwear and activity after revision surgery.

FOOT CRAMPING PAIN ??? RUNNER

HISTORY An 18-year-old male runner was referred to our sports medicine clinic with a 1-year history of cramping left foot pain. His symptoms developed insidiously when he increased his speed work training about 1 year previous, with an onset of severe left foot pain and tightness that would develop after about 20 minutes of exercise. The patient also noted occasional cramps in his calves after excessive exercise. He did not notice any swelling, numbness, tingling or burning sensations. He saw numerous private physicians and tried physical therapy, interdigital nerve block, and was immobilized in a walking cast for more than 1 month for a presumed stress fracture without effect. A family history revealed that a 29-year-old sister and uncle had symptoms of cramping in the hands with hard exercise or cold weather. PHYSICAL EXAMINATION The patient had no atrophy or fasciculations of his extremities or tongue. Neurovascular status was intact. He had no current pain associated with the foot with palpation, range of motion, or ambulation. He had full range of motion in all extremities as well as in the cervical and thoracolumbar spine. Neurologic examination, including detailed testing of mental status, cranial nerves, motor/sensory systems, muscle stretch reflexes, coordination, and gait were within normal limits, with the exception of mild proximal muscle weakness noted at the deltoids and triceps rated at 4/5 bilaterally. Distal upper and lower extremity strength were normal. DIFFERENTIAL DIAGNOSIS Compartment syndrome. Metatarsal stress fracture. Plantar fascitis. Interdigital neuroma. Myotonic syndrome. TEST AND RESULTS Blood studies, including cell count, electrolyte, chemistry panel: – Normal MRI scans of the foot: – No sign of interdigital neuroma, metatarsal stress fracture, tenosynovitis, and no evidence of tumor or mass. Stryker examination: – No abnormal pressure increase of the medial, central, and deep posterior compartments of the left and central compartment on the right foot. Serum CPK: – 687 IU/L (normal range for men, 35–232) Repeated CPK study and aldolase after rest from running for two weeks: – 669 IU/L and 9 (normal range, 1–8). Nerve conduction study – Normal Needle electromyography – At rest, abnormal sustained runs of positive sharp waves at virtually every needle site in all limbs studied – Motor unit potentials and recruitment were normal in all muscles. – Following immersion of his hands in cold water for approximately 4–5 minutes, a repeat needle examination of the patients first dorsal interossei in the hand showed a large amount of myotonic discharges. Thyroid function test, eye examination: – Normal Muscle biopsy specimen taken from quadriceps muscle: – No evidence of myotonia dystrophica, inflammation, and metabolic myopathy. FINAL/WORKING DIAGNOSIS Paramyotonia congenital. TREATMENT AND OUTCOMES Carbamazepine and mexiletine, both of which were discontinued secondary to reported adverse effects of subtle cognitive slowing. Phenytoin (400 mg q hs), which lessened the patients symptoms. The patient decided to give up running, as he was not able to maintain mileage high enough to compete successfully at an elite college level.

Percutaneous ultrasound-guided injections in the musculoskeletal system.

Ultrasound guidance is an accurate method for the delivery of therapeutic injections in the musculoskeletal system. The visualization of the needle in real time allows for reliable placement of the needle tip in the tendon sheath, bursa, or joint of interest. Both superficial and deep articulations and tendon sheaths can be targeted for diagnostic or therapeutic interventions. In addition, intratendinous calcifications, the plantar fascia, and interdigital (Morton's) neuromas can also be visualized and injected directly under real-time guidance. Performing percutaneous interventions with ultrasound ensures accurate needle tip placement and helps direct the needle away from other regional soft-tissue structures such as nearby neurovascular bundles.

Concurrent interdigital neuroma and MTP joint instability: long-term results of treatment.

An interdigital neuroma is a common source of forefoot pain, and while second metatarsophalangeal joint instability is a less common entity, it can be a concomitant source of pain. The purpose of this study was to evaluate the long-term clinical course and surgical outcomes of the treatment of these concomitant problems. 121 consecutive patients (131 feet and 136 neuromas) were evaluated and treated for a symptomatic interdigital neuroma from 1981 to 1997. Of these, 24 patients (20%) had a concurrent interdigital neuroma (IDN) and second metatarsophalangeal (MTP) capsular instability that underwent surgical treatment. At the final follow-up examination, 20 patients (21 feet) were evaluated by an independent orthopaedic surgeon with a standardized clinical and radiographic examination, patient self-assessment and outcome measures. Overall, there were 18 females and two males (21 feet) treated with an average age of 54 years at the time of surgery that returned for examination and follow-up at an average of 80 months (48 to 108 months) following surgery. Seventeen patients (85%) rated their result as good or excellent and three as fair. Six patients had mild continued symptoms referable to the second toe and none to the neuroma. Simultaneous neuroma excision and second MTP stabilization was performed in 15 cases and in six cases a staged repair was performed. The mean visual analog pain score was 1.4 (0=no pain, 10=severe pain) and mean MHAQ score was 1.13 (1-1.625) with activity modification stemming from hip, back and knee complaints. With careful patient selection and preoperative assessment, resection of an interdigital neuroma and stabilization of second metatarsophalangeal joint instability resulted in a high percentage of successful results at greater than four years following the procedure. Objective results were comparable to previous reports on the surgical treatment of isolated interdigital neuroma and crossover second toe reconstruction. Subjective patient satisfaction was high but both subjective and objective results were lower in patients with persistent symptoms of MTP instability.

Nerve problems of the foot and ankle: evaluation, diagnosis, and treatment

This review will focus on nerve problems of the foot and ankle. Entrapment syndromes along with interdigital (Morton's) neuroma comprise most of these problems. The first step in the management of these disorders is making the correct diagnosis. Knowledge of the anatomy, a thorough history and physi

Operative treatment of interdigital neuroma

Operative treatment of interdigital neuroma

Treatment of recurrent neuroma of the interdigital nerve by implantation of the proximal nerve into muscle in the arch of the foot

A prospective study was done to evaluate the results of treating recurrent "Morton's" neuroma by a technique that combined resecting the interdigital neuroma through a plantar approach and implantation of the proximal end of the nerve into an intrinsic muscle in the arch of the foot. As a part of this study, quantitative sensory testing was done for the medial plantar and medial calcaneal nerves. Seventeen recurrent interdigital neuromas were resected in 13 patients. Pain was identified on physical examination as being due to neuromas located in the first (one), second (six), third, (eight) and fourth (two) web spaces. Seven of the 13 patients were found to have, by quantitative sensory testing and physical examination, an associated tarsal tunnel syndrome responsible for symptoms related to numbness in the foot in addition to the pain of the recurrent neuroma. These patients had tarsal tunnel decompression at the time of the neuroma resection. At a mean follow-up time of 33.8 months (range 24-42 months), done by direct physician interview and examination, 80% of the patients had excellent relief of symptoms, returned to their regular job, and wore usual footwear. Twenty percent of the patients had good relief of symptoms, worked at a different job, and had to change their footwear. It is concluded that recurrent pain after a dorsal interdigital neurectomy can be treated successfully through a plantar approach with implantation of the proximal end of the nerve into an intrinsic muscle. This study also identified an association of tarsal tunnel syndrome in 54% of this series of patients with recurrent Morton's neuroma.

Operative Treatment of Interdigital Neuroma

The literature regarding the outcome of surgical treatment of interdigital neuroma is incomplete. The purpose of this study was to assess the demographics associated with the presentation of an interdigital neuroma as well as the long-term clinical results of operative resection by a single surgeon. A retrospective review of the patient records of one orthopaedic foot and ankle surgeon identified eighty-two patients who had been treated operatively for a primary, persistently painful interdigital neuroma more than three years previously. Of these eighty-two patients, sixty-six (seventy-one feet, seventy-four neuromas) returned at an average of 5.8 years for a follow-up evaluation, which included a review of the interval history since the surgery, a physical examination, a radiographic evaluation, and an assessment of the patient's satisfaction with the result of the surgery. Overall satisfaction was rated as excellent or good by fifty-six (85%) of the sixty-six patients. Forty-six (65%) of the seventy-one feet were pain-free at the time of final follow-up. The patients who had had either bilateral neuroma excision or excisions of adjacent neuromas in the same foot in a staged fashion had a slightly lower level of satisfaction, but this difference was not significant. While major activity restrictions following surgery were uncommon, mild or major shoe-wear restrictions were noted by forty-six of the sixty-six patients. Although there was subjective numbness in thirty-six of the seventy-one feet, the pattern of numbness was quite variable and it was bothersome in only four feet. With careful preoperative evaluation and patient selection, resection of a symptomatic interdigital neuroma through a dorsal approach can result in a high percentage of successful results more than five years following the procedure.

Magnetic resonance imaging of the foot and ankle.

Magnetic resonance (MR) imaging of the foot and ankle is playing an increasingly important role in the diagnosis of a wide range of foot and ankle abnormalities, as well as in planning for their surgical treatment. For an optimal MR study of the foot and ankle, it is necessary to obtain high-resolution, small-field-of-view images using a variety of pulse sequences. The most common indication for MR imaging of the foot and ankle is for the evaluation of tendon and bone abnormalities, such as osteomyelitis, occult fractures, and partial and complete tears of the Achilles, tibialis posterior, and peroneal tendons. Magnetic resonance imaging has also been shown to be helpful in the diagnosis of several soft-tissue abnormalities that are unique to the foot and ankle, such as plantar fasciitis, plantar fibromatosis, interdigital neuromas, and tarsal tunnel syndrome.