Practical US of the forefoot

EURO-MUSCULUS/USPRM Dynamic Ultrasound Protocols for Ankle/Foot

ABSTRACT

In this dynamic scanning protocol, ultrasound examination of the ankle is described using various maneuvers to assess different conditions. Real-time patient examination and scanning videos are used for better simulation of daily clinical practice. The protocol is prepared by several/international experts in the field of musculoskeletal ultrasound and within the umbrella of European Musculoskeletal Ultrasound Study Group in Physical and Rehabilitation Medicine/Ultrasound Study Group of the International Society of Physical and Rehabilitation Medicine.

Diagnostic Considerations of Intermetatarsal Bursitis: A Systematic Review

Intermetatarsal bursitis (IMB) is an inflammation of the intermetatarsal bursas. The condition causes forefoot pain with symptoms similar to those of Morton's neuroma (MN). Some studies suggest that IMB is a contributing factor to the development of MN, while others describe the condition as a differential diagnosis. Among patients with rheumatic diseases, IMB is frequent, but the scope is yet to be understood. The aim of this paper was to investigate the diagnostic considerations of IMB and its role in metatarsalgia by a systematic review approach. We identified studies about IMB by searching the electronic databases Pubmed, Embase, Cochrane Library, and Web of Science in September 2022. Of 1362 titles, 28 met the inclusion criteria. They were subdivided according to topic: anatomical studies (n = 3), studies of patients with metatarsalgia (n = 10), and studies of patients with rheumatic diseases (n = 15). We conclude that IMB should be considered a cause of pain in patients with metatarsalgia and patients with rheumatic diseases. For patients presenting with spreading toes/V-sign, IMB should be a diagnostic consideration. Future diagnostic studies about MN should take care to apply a protocol that is able to differ IMB from MN, to achieve a better understanding of their respective role in forefoot pain.

A problem-based approach in musculoskeletal ultrasonography: central metatarsalgia

Ultrasonography (US) is a useful diagnostic method that can be easily applied to identify the cause of metatarsalgia. The superficial location of structures in the foot, dynamic capability of US, and the ability to perform direct real-time evaluations of the pain site are also strong advantages of US as a modality for examining the foot. Moreover, knowing the possible pain sources to investigate when a patient has a specific site of pain will enhance the diagnostic quality of US, and will help radiologists to perform US efficiently and effectively. The purpose of this article is to review the common etiologies of metatarsalgia including Morton’s neuroma, plantar plate injury, synovitis, tenosynovitis, bursitis, and metatarsal fractures, and to discuss their US features.

Plantar forefoot pain: ultrasound findings before and after treatment with custom-made foot orthoses

PURPOSE

No prior studies investigated the role of ultrasound in the assessment of response of patients undergoing treatment of metatarsalgia with custom-made orthoses. Our aim was to describe ultrasound findings of patients with plantar forefoot pain treated with custom-made foot orthoses.

METHODS

Twenty patients (15 females; mean age: 62.6 ± 11 years) affected by metatarsalgia in 27/40 feet underwent clinical evaluation before, three months and six months after treatment with custom-made full foot insole with a support proximal and an excavation below the painful metatarsals. Ultrasound was performed before and three months after the use of orthoses to examine the presence of intermetatarsal/submetatarsal bursitis, metatarsophalangeal joints effusion, anterior plantar fat pad oedema, flexor tendinitis/tenosynovitis, and Morton's neuroma. Outcome measures were clinical response with Foot Function Index (FFI)/Visual Analogue Scale (VAS) and ultrasound features changes.

RESULTS

Median VAS and FFI before treatment were 8[5-8.5] and 45.85[32.4-59.4], respectively. After 3 and 6 months of insoles use, both median VAS (2.5 [0-5] and 0 [0-2.75], respectively) and median FFI (7.9 [3.95-20] and 0 [0-3.95], respectively) showed a significant reduction in pain and disability (p < .001). Before treatment, ultrasound revealed 22 intermetatarsal bursitis, 16 submetatarsal bursitis, 10 joint effusions, 20 fat pad oedema, 3 flexor tendinitis/tenosynovitis and 3 Morton's neuromas. After 3 months of treatment, a significant decrease of intermetatarsal bursitis (7, p < .001) was observed. No significant changes were observed in any other ultrasound parameters.

CONCLUSION

Ultrasound might be able to detect some imaging features associated with the response of forefoot pain to custom-made foot orthoses, especially intermetatarsal bursitis.

Should the webspaces be a review area for Mortons neuroma on computed tomographies performed for metatarsalgia?

Purpose

Morton’s neuroma-bursal complex (MNBC) is a common cause of metatarsalgia which is usually investigated with ultrasound. Patients presenting with metatarsalgia may also have computed tomography (CT) as part of their investigation to look for alternative causes such as stress fracture. Although CT is considered to be of most use in assessing the bones in this scenario, the soft tissues can also be reviewed. This study analyses whether MNBC can reliably be detected on CT in patients presenting with metatarsalgia.

Material and methods

43 cases were identified on the Radiology Information System where both CT and ultrasound had been undertaken to assess for metatarsalgia. Two blinded consultant musculoskeletal radiologists retrospectively reviewed the CTs to determine the presence or absence of MNBC and this was compared to the ultrasound reports.

Results

There was a mean sensitivity of 45.5% and mean specificity of 62.5%. Mean accuracy was 52.3% and Youden’s index was 0.080. There was fair agreement between the two reviewers with Cohen’s κ of 0.62.

Conclusions

Sensitivity and specificity of CT for MNBC are poor. CT should not be used as an isolated modality to make a definite diagnosis regarding the presence or absence of a MNBC.

A Rare Case of Lateral Forefoot Pain: Plantar Adventitious Bursitis

Forefoot pain is a common musculoskeletal complaint but is rarely caused by plantar adventitious bursitis. A 27-year-old female had right lateral forefoot pain for three weeks and was referred for an ultrasound examination, revealing an anechoic mass on top of the flexor digiti minimi brevis tendon. Two weeks after oral medication and a prescription of rocker-bottom shoes, her pain totally disappeared. In conclusion, ultrasound is helpful in differentiating various causes of forefoot pain, which, in this case, facilitated the detection and management of plantar adventitious bursitis.

Prediction of Clinical Prognosis according to Intermetatarsal Distance and Neuroma Size on Ultrasonography in Morton Neuroma: A Prospective Observational Study

OBJECTIVES

This study aims to evaluate the clinical importance of intermetatarsal distance, size of neuroma, and proportion of neuroma in the intermetatarsal space in examinations of Morton neuroma using ultrasonography.

METHODS

Clinical prognosis was observed prospectively after corticosteroid injections in 136 patients with Morton neuroma, and the results were compared with ultrasonographic parameters of intermetatarsal distance, size of neuroma, and proportion of neuroma in the intermetatarsal space.

RESULTS

Twenty-one patients (15%) did not respond to corticosteroid injections and underwent surgical treatment for Morton neuroma. Logistic regression analysis and receiver operating characteristic curve analysis showed that the size of the neuroma was the sole predictor of failure of corticosteroid injections (P = .002). No other factors were significant for the prediction of clinical prognosis (P > .05).

CONCLUSIONS

The size of the neuroma on ultrasonography is the sole predictor of corticosteroid injection failure, while intermetatarsal distance and proportion of neuroma in the intermetatarsal space are not significant when predicting clinical prognosis of Morton neuroma.

Utility of power Doppler ultrasonography for detecting forefoot bursae in early rheumatoid arthritis: A case report

RATIONALE

Power Doppler ultrasonography (PDUS) in musculoskeletal ultrasound (MSUS) is a sensitive and reliable method for the assessment of rheumatoid arthritis (RA). The association between ultrasound-detectable forefoot bursae and the development of RA has gained attention. However, a few studies have evaluated the utility of PDUS for examining forefoot bursae in early RA. We report the case of an RA patient who developed reduced foot mobility and had detectable intermetatarsal bursitis with remarkable power Doppler (PD) signals in MSUS at the onset of RA.

PATIENT CONCERNS

A 40-year-old Japanese woman diagnosed with palindromic rheumatism visited our department due to sustained forefoot pain and difficulty walking. The levels of both rheumatoid factor (RF) and anticitrullinated protein antibody (ACPA) were high. She had opening toes with swelling in metatarsophalangeal (MTP) joints. PDUS showed intermetatarsal bursitis with mild MTP synovitis.

DIAGNOSES

We diagnosed RA by comprehensive judgment based on the 2010 American College of Rheumatology and European League Against Rheumatism classification criteria for RA.

INTERVENTIONS

We administered 6.0 mg/wk of methotrexate (MTX) and 2.0 mg/d of prednisolone (PSL) followed by an increase of MTX to 10 mg/wk.

OUTCOMES

After those treatments, the patient's symptoms showed improvement. As of this writing, the patient's remission has been maintained for >2 months.

LESSONS

Her case suggests that PDUS is useful for the detection of forefoot bursitis, and the detection of forefoot bursitis by PDUS may provide the opportunity to make an early diagnosis of RA.

The 2017 EULAR standardised procedures for ultrasound imaging in rheumatology

BACKGROUND

In 2001, the European League Against Rheumatism developed and disseminated the first guidelines for musculoskeletal (MS) ultrasound (US) in rheumatology. Fifteen years later, the dramatic expansion of new data on MSUS in the literature coupled with technological developments in US imaging has necessitated an update of these guidelines.

OBJECTIVES

To update the existing MSUS guidelines in rheumatology as well as to extend their scope to other anatomic structures relevant for rheumatology.

METHODS

The project consisted of the following steps: (1) a systematic literature review of MSUS evaluable structures; (2) a Delphi survey among rheumatologist and radiologist experts in MSUS to select MS and non-MS anatomic structures evaluable by US that are relevant to rheumatology, to select abnormalities evaluable by US and to prioritise these pathologies for rheumatology and (3) a nominal group technique to achieve consensus on the US scanning procedures and to produce an electronic illustrated manual (ie, App of these procedures).

RESULTS

Structures from nine MS and non-MS areas (ie, shoulder, elbow, wrist and hand, hip, knee, ankle and foot, peripheral nerves, salivary glands and vessels) were selected for MSUS in rheumatic and musculoskeletal diseases (RMD) and their detailed scanning procedures (ie, patient position, probe placement, scanning method and bony/other landmarks) were used to produce the App. In addition, US evaluable abnormalities present in RMD for each anatomic structure and their relevance for rheumatology were agreed on by the MSUS experts.

CONCLUSIONS

This task force has produced a consensus-based comprehensive and practical framework on standardised procedures for MSUS imaging in rheumatology.