Sonographic anatomy and technique to image the plantar digital nerves and aid identification of a Morton's neuroma

Introduction

The anatomy of the forefoot is complex, and the sonographic assessment to image the plantar digital nerves and exclude, diagnose or discriminate between a Morton's neuroma and intermetatarsal bursitis can be challenging.

Topic description and discussion

A good appreciation of the sonographic anatomy, technique, normal and abnormal appearances is required to undertake a sonographic assessment of the forefoot and its interspaces, particularly the plantar digital nerves. This is unpacked in this paper with associated pictorial aids. Muscles, tendons, and ligaments of the interspaces and the nearby metatarsophalangeal joints and their associated soft-tissue structures are helpful sonographic landmarks to guide imaging and assessment of the common and proper plantar digital nerves and the intermetatarsal bursa. These need to be appreciated from both dorsal and plantar sonographic approaches, in both short- and long-axis imaging planes.

Conclusion

Improved understanding of the anatomy and sonographic appearances of the interspace structures can enhance the sonographic assessment of the forefoot and improve diagnosis of a Morton's neuroma and/or intermetatarsal bursitis when present to guide patient management.

Association of Interosseous Tendon Inflammation in the Hand With Different Early Arthritides in a 10-Year Magnetic Resonance Imaging Study

OBJECTIVE

Inflammation around the tendons of the hand interosseous muscles (interosseous tendon inflammation [ITI]) was recently identified on magnetic resonance imaging (MRI) in a set of patients with rheumatoid arthritis (RA) and arthralgia. We conducted a large MRI study to assess the prevalence of ITI at diagnosis of RA and of other arthritides, as well as its relationship with clinical signs.

METHODS

A total of 1,205 patients presenting with various types of early arthritis between 2010 and 2020 underwent contrast-enhanced hand MRI as part of the prospective Leiden Early Arthritis Cohort. MRI was evaluated with blinding for clinical data, for ITI lateral of metacarpophalangeal (MCP) joints 2-5, and for synovitis/tenosynovitis/osteitis. We assessed ITI presence at baseline per diagnosis and its relationship with clinical characteristics (ie, presence of hand arthritis, increased acute phase reactants, and local joint swelling and tenderness). Logistic regression and generalized estimating equations were used with adjustment for age and established local inflammation features (synovitis/tenosynovitis/osteitis).

RESULTS

A total of 36% of patients with early RA (n = 532) had ITI; this was similar in patients with anti-citrullinated protein antibody (ACPA)-negative RA (37%) and those with ACPA-positive RA (34%; P = 0.53). ITI occurred regularly in remitting seronegative symmetrical synovitis with pitting edema (60%) and connective tissue diseases (44%) and less frequently in undifferentiated arthritis (14%), psoriatic arthritis (14%), inflammatory osteoarthritis (8%), reactive arthritis (7%), crystal arthritis (7%), and peripheral spondylarthritis (4%). ITI occurred more often in diagnoses with frequent arthritis of the hands (P < 0.001) and increased acute-phase reactants (P < 0.001). Within RA, ITI occurred together with local MCP joint synovitis (odds ratio [OR] 2.4, 95% confidence interval [95% CI] 1.7-3.4), tenosynovitis (OR 2.4, 95% CI 1.8-3.3), and osteitis (OR 2.2, 95% CI 1.6-3.1) on MRI. Moreover, ITI presence was associated with local MCP joint tenderness (OR 1.6, 95% CI 1.2-2.1) and swelling (OR 1.8, 95% CI 1.3-2.6), independent of age and MRI-detected synovitis/tenosynovitis/osteitis.

CONCLUSION

ITI occurs regularly in RA and other arthritides with preferential involvement of hand joints and increased acute-phase reactants. At the MCP joint level, ITI associates independently with joint tenderness and swelling. Hence, ITI is a newly identified inflamed tissue mainly found in arthritides with particularly extensive and symptomatic inflammation.

Which inflamed tissues explain a positive metatarsophalangeal squeeze test? A large imaging study to clarify a common diagnostic procedure

OBJECTIVES

The squeeze test of MTP joints is frequently used because it is easy and cheap. It is traditionally perceived as a test for synovitis. Besides classic intra-articular synovitis, also tenosynovitis and intermetatarsal bursitis (IMB) represent synovial inflammation, albeit juxta-articularly located. Both are frequently present in RA and occasionally in other arthritides. Therefore we hypothesized that tenosynovitis and IMB contribute to a positive MTP squeeze test.

METHODS

A cross-sectional study design was used. A total of 192 early arthritis patients and 693 clinically suspect arthralgia patients underwent the MTP squeeze test and forefoot MRI at first presentation. MRI measurements in age-matched healthy controls were used to define positivity for synovitis, tenosynovitis and IMB. Logistic regression was used.

RESULTS

In early arthritis patients, synovitis [odds ratio (OR) 4.8 (95% CI 2.5, 9.5)], tenosynovitis [2.4 (1.2, 4.7)] and IMB [1.7 (1.2, 2.6)] associated with MTP squeeze test positivity. Synovitis [OR 3.2 (95% CI 1.4, 7.2)] and IMB [3.9 (1.7, 8.8)] remained associated in multivariable analyses. Of patients with a positive MTP squeeze test, 79% had synovitis or IMB: 12% synovitis, 15% IMB and 52% both synovitis and IMB. In clinically suspect arthralgia patients, subclinical synovitis [OR 3.0 (95% CI 2.0, 4.7)], tenosynovitis [2.7 (1.6, 4.6)] and IMB [1.7 (1.2, 2.6)] associated with MTP squeeze test positivity, with the strongest association for synovitis in multivariable analysis. Of positive MTP squeeze tests, 39% had synovitis or IMB (10% synovitis, 15% IMB and 13% both synovitis and IMB).

CONCLUSION

Besides synovitis, IMB contributes to pain upon compression in early arthritis, presumably due to its location between MTP joints. This is the first evidence showing that MTP squeeze test positivity is not only explained by intra- but also juxta-articular inflammation.

Intermetatarsal Bursitis, a Novel Feature of Juxtaarticular Inflammation in Early Rheumatoid Arthritis Related to Clinical Signs: Results of a Longitudinal Magnetic Resonance Imaging Study

OBJECTIVE

Intermetatarsal bursae in the forefeet possess a synovial lining similar to joints and tendon sheaths. Inflammation of these bursae (intermetatarsal bursitis [IMB]) was recently identified as specific for early rheumatoid arthritis (RA). The present study was undertaken to determine if IMB is indeed an RA feature by assessing the following: 1) the association with other local inflammatory measures (synovitis, tenosynovitis, and osteitis), 2) the association with clinical signs, and 3) whether it responds to disease-modifying antirheumatic drug (DMARD) therapy similarly to other local inflammatory measures.

METHODS

One hundred fifty-seven consecutive early RA patients underwent unilateral contrast-enhanced 1.5T forefoot magnetic resonance imaging (MRI) at diagnosis. MRIs were evaluated for IMB presence and for synovitis, tenosynovitis, and osteitis in line with the RA MRI Scoring (RAMRIS) system (summed as RAMRIS inflammation). MRIs at 4, 12, and 24 months were evaluated for IMB presence and size in patients who had IMB at baseline and received early DMARD therapy. Logistic regression and generalized estimating equations were used. Anti-citrullinated protein antibody (ACPA) stratification was performed.

RESULTS

Sixty-nine percent of RA patients had ≥1 IMB. In multivariable analysis on bursa level, presence of IMB was independently associated with local presence of synovitis and tenosynovitis, with odds ratios (OR) of 1.69 (95% confidence interval [95% CI] 1.12, 2.57) and 2.83 (95% CI 1.80, 4.44), respectively, but not osteitis. On the patient level, IMB presence was most strongly associated with tenosynovitis (OR 2.92 [95% CI 1.62, 5.24]). IMB presence was associated with local joint swelling (OR 2.7 [95% CI 1.3, 5.3]) and tenderness (OR 1.7 [95% CI 1.04, 2.9]) independent of RAMRIS inflammation. During treatment, IMB size decreased between 0 and 12 months. This decrease associated with decrease in RAMRIS inflammation, which was driven by synovitis decrease. Within ACPA-positive and ACPA-negative RA, similar results were obtained.

CONCLUSION

IMB particularly accompanies inflammation of the synovial lining of joints and tendon sheaths, showed a similar treatment response after DMARD initiation, and associates with typical clinical signs. These findings suggest that IMB represents a frequently present novel RA feature of juxtaarticular synovial inflammation.

High-Resolution Ultrasound of the Forefoot and Common Pathologies

Forefoot pain is common in clinical practice. Careful history taking and routine physical examination are initially performed for diagnosis, but imaging can confirm the clinical suspicion and play a key role in management. Ultrasound (US) can provide a visualization of the fine anatomy of the forefoot and is a useful method for evaluating various lesions causing forefoot pain. In this review, we provide the detailed anatomical structures of the forefoot and their normal appearances on US. We also focus on the most common pathologies affecting the forefoot, including plantar plate tear, sesamoiditis, bone fracture, synovitis, tenosynovitis, bursitis, Morton’s neuromas, and foreign bodies.

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.

Increased frequency of intermetatarsal and submetatarsal bursitis in early rheumatoid arthritis: a large case-controlled MRI study

Background

The forefoot is a preferential location for joint and tendon sheath inflammation in rheumatoid arthritis (RA). It also contains bursae, of which the intermetatarsal bursae have a synovial lining. Some small imaging studies suggested that intermetatarsal bursitis (IMB) and submetatarsal bursitis (SMB) are involved in RA, but their association has not been thoroughly explored. Healthy control studies suggested that lesion size might be relevant. We studied the relation between IMB and SMB in early RA, compared to other arthritides and healthy controls, and the relevance of lesion sizes.

Methods

Six hundred and thirty-four participants were studied: 157 consecutive patients presenting with early RA, 284 other arthritides, and 193 healthy controls. All underwent unilateral contrast-enhanced MRI of the forefoot at presentation. Two readers independently scored IMB and SMB and measured transverse and dorsoplantar diameters, blinded to clinical data. Subsequently, consensus was reached. Intra-reader ICC was 0.89. Logistic regression models were used, and test characteristics were calculated.

Results

IMB and SMB associated with RA independent of each other (P < 0.001) and independent of age, gender, BMI, RA-MRI inflammation, and anti-CCP-antibodies (P = 0.041). Sensitivity for RA of IMB was 69%, and for SMB 25%. Specificity for IMB was 70% compared to other arthritides, and 84% compared to healthy controls. For SMB, this was 94% and 97% respectively. Regarding lesion size, the groups had considerable overlap: no cut-off size for RA could be distinguished with high sensitivity and specificity.

Conclusion

Intermetatarsal and submetatarsal bursitis associated with early rheumatoid arthritis, contributing to the emerging evidence that inflammation of juxta-articular soft tissues is an early feature of RA.

[Sonography of the foot in rheumatology : Ultrasound diagnostics of the ankle joint and foot in the rheumatological routine]

Ultrasound examination of the joints is an essential component of diagnostics in rheumatology. Due to its easy accessibility, excellent image definition of soft tissue and bone surfaces with standardized scan sections and scoring systems, ultrasound examination of the joints enables decisions to be made on early and differential diagnostics, treatment monitoring and prognosis. Involvement of the ankle and foot is a common problem in both inflammatory and degenerative rheumatological diseases. Persisting inflammatory processes and bone destruction increase the burden of disease by causing a loss of mobility due to pain. As treatment is often prolonged it is an important issue for both the quality of life of affected patients and a burden on the resources of the healthcare system. The anatomical characteristics of the foot make it difficult to draw diagnostic conclusions by physical examination only. These diagnostic gaps in the remaining rheumatological questions can often be answered by ultrasound examination of the joint.

The relation between physical joint examination and MRI-depicted inflammation of metatarsophalangeal joints in early arthritis

BACKGROUND

The relationship between physical joint examination (PE) and MRI-detected inflammation in early inflammatory arthritis has mostly been studied in the hands. Physical examination of MTP joints is considered difficult, and for these joints, this relationship is unknown. Therefore, we studied the concordance of PE with MRI inflammation in MTP joints. Metacarpophalangeal (MCP) joints were included for comparison.

METHODS

One thousand seven hundred fifty-nine MTP(2-5) and 1750 MCP(2-5) joints of 441 consecutive patients with early arthritis underwent PE (for joint swelling) and MRI, all evaluated by two assessors. MRI was scored for synovitis, tenosynovitis, and osteitis (summed MRI inflammation). Synovial intermetatarsal bursae may enlarge upon inflammation and become palpable and were therefore also assessed. Analyses (frequencies, GEE) were performed on joint level.

RESULTS

PE and MRI were concordant in 79% of MTP joints. Of 1606 non-swollen MTP joints, 83% showed no MRI inflammation and 17% showed subclinical MRI inflammation. Of 153 swollen MTP joints, 48% had MRI inflammation and 52% (79 MTP joints) did not. Of these 79 swollen MTP joints without MRI inflammation, 31 showed intermetatarsal bursitis and 48 joints had none of these MRI abnormalities (this concerned 31% of swollen MTP joints). MTP swelling was statistically independently associated with tenosynovitis (OR 2.21, 95% CI 1.1-4.3) and intermetatarsal bursitis (OR 2.91, 95% CI 1.8-4.8). MTP joints showed subclinical inflammation less often than MCP joints (17% vs. 34%, P < 0.001). Swollen MTP joints showed MRI inflammation less often than swollen MCP joints (48% vs. 88%, P < 0.001).

CONCLUSIONS

The absence of swelling of MTP joints in early arthritis is mostly accompanied by the absence of MRI-detected inflammation. Swollen MTP joints are, in addition to synovitis, also explained by tenosynovitis and intermetatarsal bursitis and partly unexplained by MRI. Their clinical relevance must be determined in longitudinal studies.

Provision of foot and ankle care services for people with rheumatic and musculoskeletal disease across Europe

BACKGROUND

The aim of the present study was to explore the variation in the provision of care for people with rheumatic and musculoskeletal diseases (RMDs), and foot and ankle problems between European healthcare systems.

METHODS

An electronic questionnaire was developed and piloted in seven countries prior to being distributed to the presidents of all 22 national health professionals in rheumatology associations within the European League Against Rheumatism (EULAR). Summary data were obtained using SPSS V22. Ethical approval was sought from the Medical Research Ethics Committee of University of Malaga (CEUMA-91-2015-H).

RESULTS

Sixteen questionnaires (73% response rate) were completed (Austria, Belgium, Czech Republic, Denmark, France, Hungary, Ireland, Italy, Malta, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the UK). All 16 respondents indicated that foot and ankle healthcare services were provided in their country, but only three countries had services specializing in RMD-related foot and ankle problems (the Netherlands, the UK and Malta). The professions providing care varied, depending on the pathology and the country. Foot and ankle pain was mostly treated by rheumatologists and physiotherapists; foot and ankle deformities by orthopaedic surgeons and orthotist/prosthetists; and foot and ankle ulcers by nurses. Services were predominantly delivered through the public sector, and in secondary care (hospital) settings.

CONCLUSIONS

Only three countries reported having specialist foot and ankle services addressing the needs of people with RMDs. Variation was seen in the professions which provided care between countries, and also between the foot and ankle pathologies cared for. There is a lack of clinical pathways and guidelines for the management of patients with RMD-related foot and ankle problems.

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.

A pilot investigation of the prevalence of US-detectable forefoot joint pathology and reported foot-related disability in participants with systemic lupus erythematosus

Background

The main aim of this study was to determine the prevalence of US-detectable forefoot bursae, metatarsophalangeal (MTP) joint and metacarpophalangeal (MCP) joint synovial hypertrophy (SH), Power Doppler (PD) signal or erosion in participants with systemic lupus erythematosus (SLE). A secondary aim was to determine the strength of potential association between patient reported foot-related disability and US-detected forefoot bursae, MTP joint SH, PD signal or erosion in participants with SLE.

Method

A cross-sectional observational study of 20 participants with SLE was completed to determine the prevalence of US-detected forefoot bursal, MTP and MCP joint pathology. Patient-reported foot-related impairment and activity limitation (accumulatively referred to as disability) were also recorded. Spearmans’ Rank Correlation analyses were completed to determine the potential strength of association between US-detected pathology and patient report disability.

Results

The prevalence of MTP joint SH and PD was 80 % (16/20) and 10 % (2/20), respectively. The prevalence of MCP joint SH and PD was 60 % (12/20) and 30 % (6/20) respectively. A significant association was noted between PD scores for the MTP joints and MCP joints (r = 0.556; p = 0.011) although this was not demonstrated for SH scores (r = 0.176; p = 0.459). Significant associations between forefoot bursal prevalence and MTP joint PD were noted (r = 0.467; p = 0.038). The prevalence of bursae and bursal PD (grade 2 or above) was 100 % (20/20) and 10 % (2/20), respectively. Moderate foot-related impairment and activity limitation was reported by 95 and 85 % of participants respectively.

Conclusion

This pilot study suggests that US-detected MTP, MCP joint and forefoot bursal abnormalities may be prevalent in participants with SLE and they may experience a moderate level of foot-related disability. Further research is required to substantiate these preliminary findings.

The reliability of a novel magnetic resonance imaging-based tool for the evaluation of forefoot bursae in patients with rheumatoid arthritis: the FFB score

OBJECTIVE

The aim of this study was to determine the reliability of an MRI-based score that evaluates forefoot bursae (FFBs) in patients with RA.

METHODS

Items for inclusion, grading criteria and MRI sequences were determined iteratively. The score was evaluated in 30 patients with established RA. Reader agreement was evaluated using the percentage of exact/close agreement, Bland-Altman plots, kappa and intraclass correlation coefficient analyses.

RESULTS

The FFB score assesses nine forefoot regions and contains four items: presence, shape, enhancement and magnetic resonance characteristics. The FFB score showed moderate to good intra- and interreader agreement (κ range = 0.5-0.9 and 0.47-0.87, respectively).

CONCLUSION

The FFB score is adequately reliable in the evaluation of bursa-like lesions of the forefoot in patients with RA.

Practical US of the forefoot

Disorders affecting the forefoot are common in the clinical practice. Accurate history and physical examination are the mainstays of diagnosis but imaging modalities are frequently obtained to confirm the clinical suspicion and plan appropriate treatment. In this article we will present the ultrasound (US) technique of examination of the forefoot followed by a brief description of the normal US anatomy and of US appearance of the most frequent forefoot disorders; rheumatoid arthritis, osteoarthritis, overuse arthropathy, Morton neuromas, bursitis, mucoid cysts, foreign bodies, bone disorders.

Forefoot: a basic integrated imaging perspective for radiologists

Imaging of the forefoot is increasingly requested for patients with metatarsalgia. Awareness with specific anatomic arrangements exclusive for the forefoot and widely variable pathologic entities associated with metatarsalgia helps the radiologist to tailor a cost-effective imaging approach. This will enable reaching a specific diagnosis as much as possible with subsequent proper patient management. This pictorial review aims to provide basic understanding for the different imaging modalities used in studying the forefoot. After that, certain anatomic arrangements exclusive for the forefoot are discussed. The final section of this review describes the imaging findings of some common forefoot problems.

Training the next generation of clinical researchers: evaluation of a graduate podiatrist research internship in rheumatology

Background

The aim of this study was to evaluate the effectiveness of the Arthritis Research UK funded graduate internship scheme for podiatrists and to explore the experiences of interns and mentors.

Methods

Nine new graduates completed the internship programme (July 2006–June 2010); six interns and two mentors participated in this study. The study was conducted in three phases. Phase 1: quantitative survey of career and research outcomes for interns. Phase 2 and 3: qualitative asynchronous interviews through email to explore the experiences of interns and mentors. Interpretive phenomenological analysis (IPA) of coded transcripts identified recurring themes.

Results

Research outputs included ten peer reviewed publications with authorial contributions from interns, 23 conference abstract presentations and one subsequent ‘Jewel in the Crown’ award at the British Society for Rheumatology Conference. Career progression includes two National Institute for Health research (NIHR) PhD fellowships, two Arthritis Research UK PhD fellowships, one NIHR Master of Research fellowship and one specialist rheumatology clinical post. Two interns are members of NIHR and professional body committees.

Seven important themes arose from the qualitative phases: perceptions of the internship pre-application; internship values; maximising personal and professional development; psychosocial components of the internship; the role of mentoring and networking; access to research career pathways; perceptions of future developments for the internship programme. The role of mentorship and the peer support network have had benefits that have persisted beyond the formal period of the scheme.

Conclusions

The internship model appears to have been perceived to have been valuable to the interns’ careers and may have contributed significantly to the broader building of capacity in clinical research in foot and ankle rheumatology. We believe the model has potential to be transferable across health disciplines and on national and international scales.

Forefoot pathology in rheumatoid arthritis identified with ultrasound may not localise to areas of highest pressure: cohort observations at baseline and twelve months

BACKGROUND

Plantar pressures are commonly used as clinical measures, especially to determine optimum foot orthotic design. In rheumatoid arthritis (RA) high plantar foot pressures have been linked to metatarsophalangeal (MTP) joint radiological erosion scores. However, the sensitivity of foot pressure measurement to soft tissue pathology within the foot is unknown. The aim of this study was to observe plantar foot pressures and forefoot soft tissue pathology in patients who have RA.

METHODS

A total of 114 patients with established RA (1987 ACR criteria) and 50 healthy volunteers were assessed at baseline. All RA participants returned for reassessment at twelve months. Interface foot-shoe plantar pressures were recorded using an F-Scan® system. The presence of forefoot soft tissue pathology was assessed using a DIASUS musculoskeletal ultrasound (US) system. Chi-square analyses and independent t-tests were used to determine statistical differences between baseline and twelve months. Pearson's correlation coefficient was used to determine interrelationships between soft tissue pathology and foot pressures.

RESULTS

At baseline, RA patients had a significantly higher peak foot pressures compared to healthy participants and peak pressures were located in the medial aspect of the forefoot in both groups. In contrast, RA participants had US detectable soft tissue pathology in the lateral aspect of the forefoot. Analysis of person specific data suggests that there are considerable variations over time with more than half the RA cohort having unstable presence of US detectable forefoot soft tissue pathology. Findings also indicated that, over time, changes in US detectable soft tissue pathology are out of phase with changes in foot-shoe interface pressures both temporally and spatially.

CONCLUSIONS

We found that US detectable forefoot soft tissue pathology may be unrelated to peak forefoot pressures and suggest that patients with RA may biomechanically adapt to soft tissue forefoot pathology. In addition, we have observed that, in patients with RA, interface foot-shoe pressures and the presence of US detectable forefoot pathology may vary substantially over time. This has implications for clinical strategies that aim to offload peak plantar pressures.

Assessment of the natural history of forefoot bursae using ultrasonography in patients with rheumatoid arthritis: a twelve-month investigation

OBJECTIVE

To determine the natural history and clinical significance of forefoot bursae over a 12-month period in patients with rheumatoid arthritis (RA).

METHODS

Patients with RA (n=149) attending rheumatology outpatient clinics were assessed at baseline. A total of 120 participants, mean±SD age 60.7±12.1 years and mean±SD disease duration 12.99±10.4 years, completed the 12-month followup (98 women, 22 men, 93 rheumatoid factor positive, 24 rheumatoid factor negative, and 3 unknown). Musculoskeletal ultrasound (US) was used to identify forefoot bursae in all of the participants. Clinical markers of disease activity (well-being visual analog scale [VAS], erythrocyte sedimentation rate [ESR], C-reactive protein [CRP] level, and Disease Activity Score in 28 joints [DAS28]) and foot symptoms on the Leeds Foot Impact Scale (LFIS) Questionnaire were recorded on both occasions.

RESULTS

Presence of US-detectable forefoot bursae was identified in 93.3% of returnee (n=120) participants (individual mean 3.7, range 0-11) at baseline. Significant associations were identified between bursae presence and patient-reported foot impact for impairment/footwear (LFISIF ; baseline: r=0.226, P=0.013 and 12 months: r=0.236, P=0.009) and activity limitation/participation restriction (LFISAP; baseline: r=0.254, P=0.005 and 12 months: r=0.235, P=0.010). After 12 months, 42.5% of participants had an increase in the number of US-detectable forefoot bursae and 45% of participants had a decrease. Changes in bursae number significantly correlated with changes in LFISIF (r=0.216, P=0.018) and LFISAP (r=0.193, P=0.036). No significant associations were identified between changes in bursae and changes in global well-being VAS, ESR, CRP level, or DAS28.

CONCLUSION

The findings of this study suggest that forefoot bursae may regress or hypertrophy over time in patients with RA, and that these changes may be associated with self-reported foot impairment and activity restriction.

Improvement in symptoms and signs in the forefoot of patients with rheumatoid arthritis treated with anti-TNF therapy

Background

Inhibition of tumour necrosis factor (TNF) is an effective way of reducing synovitis and preventing joint damage in rheumatoid arthritis (RA), yet very little is known about its specific effect on foot pain and disability. The aim of this study was to evaluate whether anti-TNF therapy alters the presence of forefoot pathology and/or reduces foot pain and disability.

Methods

Consecutive RA patients starting anti-TNF therapy (infliximab, etanercept, adalimumab) were assessed for presence of synovial hypertrophy and synovitis in the 2^nd and 5^th metatarso-phalangeal (MTP) joints and plantar forefoot bursal hypertrophy before and 12 weeks after therapy. Tender MTP joints and swollen bursae were established clinically by an experienced podiatrist and ultrasound (US) images were acquired and interpreted by a radiologist. Assessment of patient reported disease impact on the foot was performed using the Manchester Foot Pain and Disability Index (MFPDI).

Results

31 patients (24 female, 7 male) with RA (12 seronegative, 19 seropositive) completed the study: mean age 59.6 (SD 10.1) years, disease duration 11.1 (SD 10.5) years, and previous number of Disease Modifying Anti Rheumatic Drugs 3.0 (1.6). Significant differences after therapy were found for Erythrocyte Sedimentation Rate (t = 4.014, p < 0.001), C-reactive protein (t = 3.889, p = 0.001), 28 joint Disease Activity Score (t = 3.712, p = 0.0001), Visual Analog Scale (t = 2.735, p = 0.011) and Manchester Foot Pain and Disability Index (t = 3.712, p = 0.001).

Presence of MTP joint synovial hypertrophy on US was noted in 67.5% of joints at baseline and 54.8% of joints at twelve weeks. Presence of plantar forefoot bursal hypertrophy on US was noted in 83.3% of feet at baseline and 75% at twelve weeks. Although there was a trend for reduction in observed presence of person specific forefoot pathology, when the frequencies were analysed (McNemar) this was not significant.

Conclusions

Significant improvements were seen in patient reported foot pain and disability 12 weeks after commencing TNF inhibition in RA, but this may not be enough time to detect changes in forefoot pathology.