The role of MRI and ultrasound imaging in Morton’s neuroma and the effect of size of lesion on symptoms

Long-term results of neurectomy in the treatment of Morton's neuroma: more than 10 years' follow-up

PURPOSE

The objective of this retrospective study was to evaluate the long-term follow-up results of neurectomy clinical outcomes and complications in the treatment of Morton's neuroma.

MATERIALS AND METHODS

A total of 19 patients (19 different feet) were treated for Morton's neuroma by excision of the interdigital nerve at our institute between May 1997 and May 1999. Thirteen (13 feet) of them were followed up. The 13 patients were female and had an average age of 43 years (range 34-54 years) at the time of the operation. The patients were followed-up for a mean of 10.5 years (range 10.0-12.2 years) and scored using the American Orthopaedic Foot & Ankle Society (AOFAS) forefoot scoring system and Visual Analogue Scale (VAS) score. Subjective satisfaction was evaluated at the final follow-up.

RESULTS

Eight patients scored more than 90 on the AOFAS forefoot scoring system. The VAS score was improved in all patients. The mean preoperative VAS score was 8.6 ± 0.8 cm (7-10) and the mean follow-up VAS score was 2.4 ± 1.8cm (0-6), which indicated no significant difference (P > .05). The final follow-up satisfaction results indicated that 4 patients were completely satisfied with the operation, 4 were satisfied with minor reservations, 5 were satisfied with major reservations, and no patient was unsatisfied. Neurectomy to treat Morton's neuroma had a good satisfaction rate (61%). Eleven of the patients complained of numbness on the plantar aspect of the foot adjacent to the interspace, and 2 of these 11 patients complained of disability induced by severe numbness. There was a complaint of residual pain by 1 patient. There were no skin problems on the operation lesions.

CONCLUSION

The long-term results of neurectomy clinical outcomes in Morton's neuroma are slightly worse than the short- and mid-term results.

LEVELS OF EVIDENCE

Therapeutic, Level IV, Retrospective case series.

Beyond the joints: neurological involvement in rheumatoid arthritis

Although arthritis is the most notable component, rheumatoid arthritis (RA) is a systemic inflammatory disorder where extra-articular manifestations are common; among them, central and peripheral nervous system involvement is frequent and associated with significant morbidity and, in some cases, reduced life span. It may produce a myriad of symptoms and signs ranging from subtle numbness in a hand, to quadriparesis and sudden death. Central and peripheral neurologic manifestations may arise from structural damage produced by RA in diarthroidal joints, by the systemic inflammatory process of the disease itself or by the drugs used to treat it. Neurologic syndromes may appear suddenly or developed slowly through months, and emerge early or after years of having RA. Neurologic manifestations may be easily overlooked or incorrectly assigned to peripheral arthritis unless the attending physician is aware of these complications. In this article, we review neurologic involvement in RA patients with emphasis on clinical approach for early detection.

Morton's neuroma: clinical testing and imaging in 76 feet, compared to a control group

BACKGROUND

Morton's neuroma is a mechanically induced degenerative neuropathy.

METHODS

We compared clinical and MRI findings in 76 feet treated operatively for Morton's neuroma and 40 feet with different pathologies (controls).

RESULTS

In the 'treatment group' web space tenderness (WST) was positive in 95%, foot squeeze (SQU) in 88%, plantar percussion (PLP) in 61%, and toe tip sensation deficit (TTSD) in 67%. MRI identified neuromata in 97%. Histological examination confirmed neuroma excision in 99%. Frequency of positive tests was significantly higher in the treatment group compared to controls. MRI revealed (asymptomatic) neuromata in 10/40 (25%) feet in the control group. TTSD was similarly positive in asymptomatic and symptomatic neuromata. TTSD in association with any other test being positive, was significantly more frequent in symptomatic neuromata.

CONCLUSIONS

The diagnosis of Morton's neuroma, based on clinical and imaging findings, was accurate. Positive clinical testing was more frequent in the 'treatment' group compared to the 'control' group.

Interdigital neuralgia

Interdigital neuralgia affects a significant number of individuals, with an average age of presentation in the sixth decade and a 4- to 15-fold increased prevalence in women. Historical descriptions date back to the 19th century. Nonoperative treatment with shoe modifications, metatarsal pads, and injections provides relief for most, but long term, 60% to 70% of patients eventually elect to have surgery. Although excision can be performed through a dorsal or plantar approach, we prefer the dorsal incision to prevent scar formation on the plantar aspect of the foot. Satisfactory results are common but not certain with reports of excellent or good ranging from 51% to 93%.

Relationships between pathology and pain severities: a review

The relationships between pathology severity and pain severity are reviewed using the literature available for humans. The aim is to help veterinary radiologists, physicians and pathologists recognise the disorders in which severity of a lesion is likely to be related to the severity of pain or to incipient pain. Specific features or lesions within the following conditions showed a relationship with pain score, which was usually assessed with a visual analogue scale: inflammation; pancreatitis; ileitis; mucositis; fasciitis; synovitis; arthritis; lower back pain; disc herniation; sciatica; scoliosis; myalgia; cancer; arteriosclerosis; skin ulcers; mastalgia; skin and oral neuropathies; endometriosis; hepatopathy and chronic pulp diseases of the teeth. As experience with magnetic resonance imaging grows, there will be further opportunities to look for quantitative relationships in humans between pathology and pain severities. This information will be useful to veterinarians and other people working with animals in evaluating pain in animals in their care.

Morton neuroma: MR imaging after resection--postoperative MR and histologic findings in asymptomatic and symptomatic intermetatarsal spaces

PURPOSE

To evaluate the prevalence of postoperative magnetic resonance (MR) imaging findings in asymptomatic and symptomatic patients after resection of Morton neuroma.

MATERIALS AND METHODS

This study was approved by the institutional review board. Informed consent was obtained from each participant. Fifty-eight consecutive patients (46 women, 12 men) who had undergone resection of a painful Morton neuroma (90 Morton neuromas were removed in 66 feet), pre- and postoperative MR imaging, and clinical follow-up for a minimum of 2 years after surgery were identified. Two experienced musculoskeletal radiologists evaluated MR images with regard to the presence of presumed recurrent Morton neuroma, scar, or intermetatarsal bursitis. The prevalence of abnormalities in asymptomatic and symptomatic intermetatarsal spaces was determined. The results of the second radiologist were used only to determine interobserver reliability. The kappa statistics were obtained to assess interobserver agreement. Seven patients with presumed recurrent Morton neuroma underwent repeat surgery.

RESULTS

Clinically speaking, 68 intermetatarsal spaces (44 of 58 patients [76%], 47 feet) were asymptomatic at follow-up and 22 (14 of 58 patients [24%], 19 feet) were symptomatic. A presumed Morton neuroma was found in 18 (26%) of the asymptomatic spaces and 11 (50%) of the symptomatic spaces. A presumed scar was found in six (9%) of the asymptomatic spaces and two (9%) of the symptomatic spaces. A presumed intermetatarsal bursitis was found in six (9%) of the asymptomatic spaces and six (27%) of the symptomatic spaces. Interobserver agreement for presumed recurrent Morton neuroma was substantial (kappa = 0.64). Histologic examination of presumed recurrent Morton neuroma revealed fibrous tissue but no sign of peripheral neural tissue.

CONCLUSION

MR imaging after Morton neuroma resection commonly reveals Morton neuroma-like abnormalities in asymptomatic and symptomatic intermetatarsal spaces.

Sciatic neuroma presenting forty years after above-knee amputation

We report a case of a sciatic neuroma presenting forty years after above knee amputation. Patients developing neuroma following a limb amputation can present with stump pain which is commonly resistant to medical intervention. The length of interval from the initial injury to presentation is widely variable. Diagnosis relies on clinical suspicion and accurate assessment, radiological imaging and, if indicated, surgical exploration. MRI provides a better soft tissue definition than CT and is more accurate in identifying small lesions than ultrasound. The aim of treatment for symptomatic neuroma is pain relief and improvement of function. This is often achieved by surgical excision.

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%.

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.

Morton neuroma: evaluated with ultrasonography and MR imaging

Objective

The purpose of this study was to compare the diagnostic accuracy of both ultrasonography (US) and magnetic resonance imaging (MRI) for the assessment of Morton neuroma.

Materials and Methods

Our study group was comprised of 20 neuromas from 17 patients, and the neuromas were confirmed on surgery following evaluation with US, MRI, or both US and MRI. The diagnostic criterion for Morton neuroma, as examined by US, was the presence of a round or ovoid, well-defined, hypoechoic mass. The diagnostic criterion, based on MR imaging, was a well defined mass with intermediate to low signal intensity on both the T1- and T2-weighted images. The retrospective comparison between the sonographic and MR images was done by two experienced radiologists working in consensus with the surgical and pathologic correlations.

Results

The detection rate of Morton neuroma was 79% for 14 neuromas from 11 patients who had undergone US followed by an operation. The detection rate was 76% for 17 neuromas from 15 patients who had undergone MRI and a subsequent operation. The mean size of the examined neuromas was 4.9 mm on the US images and it was 5.1 mm on the MRI studies. Ten neuromas (71%) were 5 mm or less as measured by US, and three neuromas were not detected, whereas on the MRI analysis, 10 neuromas (59%) were 5 mm or less and four neuromas were not visualized. Among the patients examined during postoperative follow-up, symptoms were completely relieved in 85% and the symptoms were partially relieved in 15%.

Conclusion

US and MR imaging are comparable modalities with high detection rate for the evaluation of Morton neuroma.

Role of toe flexor tendoscopy in management of an unusual cause of metatarsalgia

The purpose of this study is to describe an endoscopic approach to toe flexor tendons at the level of metatarsal head region. And this study is a kind of retrospective case series. Three patients with toe flexor tenosynovitis were evaluated after a follow-up of 2 years after toe flexor tendoscopy. One patient suffered from infective toe flexor tendosynovitis resulting from a penetrating injury and other two patients suffered from idiopathic focal toe flexor tenosynovitis. Pre-operative metatarsalgia subsided after toe flexor tendoscopy. No endoscopy-related complication was observed. Toe flexor tendoscopy can be an effective operative means in the management of focal toe flexor tenosynovitis.

Intermetatarsal compression neuritis

Intermetatarsal compression neuritis can be a disabling condition. Individuals who don't respond well to initial treatments are left with persistent pain and frustration. The conservative approach to the treatment of neuromas includes shoe modifications, padding, orthotics, cortisone injections, and serial alcohol sclerosing injections. When a person has failed conservative treatment for a forefoot neuroma, surgery can be considered to alleviate pain and treat the condition. This article describes several different surgical approaches such as neurectomy, carbon dioxide laser, and neurolysis. Results to date show that decompression is similar to neurectomy surgery, if not more successful.

Quality of reporting of orthopaedic diagnostic accuracy studies is suboptimal

Complete and accurate reporting of diagnostic research are essential to assess the validity of its results. To improve the quality of reporting of diagnostic accuracy studies, the Standards for Reporting of Diagnostic Accuracy (STARD) steering committee has developed a checklist of 25 items. We asked whether the quality of reporting of diagnostic accuracy studies published in three major orthopaedic journals (Clinical Orthopaedics and Related Research, Journal of Bone and Joint Surgery British Volume, and Journal of Bone and Joint Surgery American Volume) would be similar across levels of study, journals, and years of publication, and would be similar to other subspecialty journals. We identified 37 articles from 2002-2004 diagnostic accuracy studies and applied the STARD checklist and scoring system. The scores ranged from 6.6 to 21.4 with a mean of 15 +/- 3.3. Only 38% of the articles (14 of 37) reported more than 2/3 of the items, and the majority failed to report nine specific items. The mean STARD scores were similar between the studies with different levels of evidence, across the three journals, and across the three years of publication. They were similar to scores for other subspecialty journals. The current standards of reporting of diagnostic accuracy studies in orthopaedic journals are suboptimal.

Use of high-resolution ultrasound in evaluation of the forefoot to differentiate forefoot nerve entrapments

Forefoot pain can have single or multiple etiologies, and frequently pain is attributed solely to a forefoot nerve entrapment. It is well known that forefoot nerve entrapments, such as Morton's, can be falsely assumed to be the cause of forefoot pain when in fact other factors, such as plantar plate disturbances, are the true cause. Frequently, the cause of the patient's forefoot pain starts as a forefoot nerve entrapment, but then, as a result of treatment with a corticosteroid injection, other pathologies manifest, such as plantar plate rupture. The development of high-resolution, high-frequency ultrasound scanners has opened the door to in-depth examination of peripheral nerves as well as small pericapsular and intracapsular joint structures of the foot and ankle. In the hands of an experienced clinician, ultrasound can play an important role in differentiating nerve lesions and entrapment syndromes from nonneurogenic pain generators, such as tendons, ligaments, fasciae, and joint capsules. The focus of this article is the forefoot, where differentiation of neuroma, neuritis, and capsulitis can be difficult.

Role of toe flexor tendoscopy in management of an unusual cause of metatarsalgia

The purpose of this study is to describe an endoscopic approach to toe flexor tendons at the level of metatarsal head region. And this study is a kind of retrospective case series. Three patients with toe flexor tenosynovitis were evaluated after a follow-up of 2 years after toe flexor tendoscopy. One patient suffered from infective toe flexor tendosynovitis resulting from a penetrating injury and other two patients suffered from idiopathic focal toe flexor tenosynovitis. Pre-operative metatarsalgia subsided after toe flexor tendoscopy. No endoscopy-related complication was observed. Toe flexor tendoscopy can be an effective operative means in the management of focal toe flexor tenosynovitis.

Morton neuroma: comparative results of two conservative methods

BACKGROUND

The initial treatment of Morton neuromas consists of conservative methods that include shoe modifications and steroid injections. The purpose of this prospective study was to compare the efficacy of these two methods to determine which is more effective as the initial treatment method.

METHODS

Eighty-two patients with Morton neuromas were randomly assigned to receive either footwear modification with orthoses or steroid injections as initial treatment. Outcomes were evaluated at 1 month, 6 months, and 12 months.

RESULTS

Patient satisfaction was significantly better (p < 0.01) in the group treated with steroid injections than those treated with shoe modifications at all three followup intervals. At 12-month followup, 82% of those treated with steroid injections had complete or partial relief of pain compared to 63% of those treated with footwear modifications alone.

CONCLUSION

Steroid injections as initial treatment and shoe modifications with steroid injections at 6 months appear to give better results in Morton neuromas than shoe modifications alone, but the difference in the two groups were not statistically significant at one year followup.

Tumours and tumour-like lesions in the foot and ankle

We present a spectrum of tumour and tumour-like lesions in the foot and ankle in which a specific diagnosis can be made or strongly suggested on the basis of location, imaging features and the relevant clinical findings. Characteristic imaging appearances are emphasized.