The Tophus Impact Questionnaire (TIQ-20): responsiveness to change during urate-lowering therapy

OBJECTIVES

In 2015, the 20-item Tophus Impact Questionnaire (TIQ-20) was developed as a tophus-specific patient reported outcome measure. The aim of this study was to determine whether TIQ-20 scores change during urate-lowering therapy.

METHODS

We analysed data from a two-year clinical trial of allopurinol dose escalation using a treat-to-target serum urate approach. For participants with tophaceous gout, the longest diameter of up to three index tophi was measured using Vernier calipers and the TIQ-20 was recorded at study visits. Participants at the one site were invited into a dual energy CT (DECT) sub-study. Participants were included in this analysis if they had tophaceous gout and TIQ-20 scores available at baseline, Year 1, and Year 2 (n = 58, 39 with DECT data). Data were analysed using mixed model approach to repeated measures.

RESULTS

Improvements were observed in all tophus measures over the two-year period. The mean (SD) TIQ-20 scores reduced over two years from 3.59 (1.77)-2.46 (1.73), P< 0.0001, and the mean (95%CI) TIQ-20 change over the two years was -1.13 (-1.54, -0.71). Effect size (Cohen's d) for the change in the sum of the index tophi diameter over two years was 0.68, for DECT urate volume was 0.50, and for the TIQ-20 was 0.71.

CONCLUSION

For people with tophaceous gout treated with allopurinol using a treat to target serum urate approach, improvements in TIQ-20 occur, as well as improvements in physical and imaging tophus measures. These findings demonstrate that the TIQ-20 is a responsive patient-reported instrument of tophus impact.

Perforating Gout: Expanding the Differential for Transepidermal Elimination

Perforating dermatoses are dermatologic disorders with transepidermal elimination (TE) of dermal substances. While TE is typically associated with collagen and elastin, it can also occur as a secondary event in other processes, and it is important to keep a broad differential. We present a case of perforating tophaceous gout, which underscores the need for a thoughtful approach to perforating disorders. An updated review of recent literature is also presented.

Surgical Management of Tophaceous Gout in the Upper Limb

PURPOSE

Gouty tophi are a clinical manifestation of hyperuricemia in advanced stages. They can produce pain, functional limitation, and severe deformities. Patients with severe symptoms require short-term symptomatic solutions that standard medical management is not able to provide. The objective of this study was to present the results obtained with the surgical management of tophaceous gout in the upper limb, as well as present a detailed characterization of the disease in the upper limb.

METHODS

Databases of the hand surgery service of a quaternary care hospital were reviewed to identify patients aged >18 years old undergoing tophi resection in the upper limbs between 2014 and 2020. Medical history records were reviewed retrospectively, and the relevant data were extracted to establish demographic profile, clinical presentation, anatomic distribution, postoperative outcomes, and additional procedures required.

RESULTS

The most frequent symptom was pain (83%), followed by limited range of motion (56%), deformity (50%), and daily living/occupational activity limitation (28%). The main indications for surgical management were the presence of deformity, pain, and/or limited range of motion. The most frequently affected anatomic sites were the metacarpophalangeal joints, followed by the elbows, proximal interphalangeal joints, and proximal phalanges. The postoperative complication rate was 28%. The most common complications were operative site infections and wound dehiscence. Decreased pain was associated with surgical resection. Additional procedures, such as extensor tenorrhaphy and local flaps, were required in 47.2% of patients.

CONCLUSION

Surgical resection of tophi can decrease pain. Although surgery is associated with a high rate of complications, most are minor.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Amplification of Inflammation by Lubricin Deficiency Implicated in Incident, Erosive Gout Independent of Hyperuricemia

OBJECTIVE

In gout, hyperuricemia promotes urate crystal deposition, which stimulates the NLRP3 inflammasome and interleukin-1β (IL-1β)-mediated arthritis. Incident gout without background hyperuricemia is rarely reported. To identify hyperuricemia-independent mechanisms driving gout incidence and progression, we characterized erosive urate crystalline inflammatory arthritis in a young female patient with normouricemia diagnosed as having sufficient and weighted classification criteria for gout according to the American College of Rheumatology (ACR)/EULAR gout classification criteria (the proband).

METHODS

We conducted whole-genome sequencing, quantitative proteomics, whole-blood RNA-sequencing analysis using serum samples from the proband. We used a mouse model of IL-1β-induced knee synovitis to characterize proband candidate genes, biomarkers, and pathogenic mechanisms of gout.

RESULTS

Lubricin level was attenuated in human proband serum and associated with elevated acute-phase reactants and inflammatory whole-blood transcripts and transcriptional pathways. The proband had predicted damaging gene variants of NLRP3 and of inter-α trypsin inhibitor heavy chain 3, an inhibitor of lubricin-degrading cathepsin G. Changes in the proband's serum protein interactome network supported enhanced lubricin degradation, with cathepsin G activity increased relative to its inhibitors, SERPINB6 and thrombospondin 1. Activation of Toll-like receptor 2 (TLR-2) suppressed levels of lubricin mRNA and lubricin release in cultured human synovial fibroblasts (P < 0.01). Lubricin blunted urate crystal precipitation and IL-1β induction of xanthine oxidase and urate in cultured macrophages (P < 0.001). In lubricin-deficient mice, injection of IL-1β in knees increased xanthine oxidase-positive synovial resident M1 macrophages (P < 0.05).

CONCLUSION

Our findings linked normouricemic erosive gout to attenuated lubricin, with impaired control of cathepsin G activity, compounded by deleterious NLRP3 variants. Lubricin suppressed monosodium urate crystallization and blunted IL-1β-induced increases in xanthine oxidase and urate in macrophages. The collective activities of articular lubricin that could limit incident and erosive gouty arthritis independently of hyperuricemia are subject to disruption by inflammation, activated cathepsin G, and synovial fibroblast TLR-2 signaling.

Ultrasonography in the prediction of gout flares: a 12-month prospective observational study

OBJECTIVES

To evaluate whether US findings indicating MSU deposits and US-detected inflammation (i.e. power Doppler signal) predict gout flares over 12 months.

METHODS

Gout patients on urate-lowering therapy for at least the preceding 6 months were enrolled consecutively in this 12-month prospective, observational, single-centre study. A nested case-control analysis was performed. Cases were participants with at least one flare in the follow-up period, while controls did not self-report any gout flare. The US assessment included elbows, wrists, second MCP joints, knees, ankles, and first MTP joints. The US findings indicating MSU deposits [i.e. aggregates, double contour (DC) sign and tophi] were identified as present/absent according to the Outcome Measure in Rheumatology definitions. Power Doppler signal was scored semiquantitatively. Summated scores were calculated for each US finding.

RESULTS

Eighty-one gout participants were enrolled, and 71 completed the study. Thirty (42.3%) of 71 participants experienced at least one flare over 12 months, with a median of 2.0 flares. Cases had a greater US burden of MSU deposits (6.7 ± 4.7 vs 2.9 ± 2.6, P = 0.01) and power Doppler signal (3.73 ± 3.53 vs 0.82 ± 1.44, P < 0.01) than controls, at baseline. The baseline US scores indicating MSU deposits and US-detected inflammation were significantly associated with the occurrence (total MSU score, adjusted odds ratio:1.75, 95% CI: 1.26, 2.43; power Doppler score, adjusted odds ratio: 1.63, 95% CI: 1.12, 2.40) and the number (total MSU score, adjusted incidence risk ratio: 1.17, 95% CI: 1.08, 1.26; power Doppler score, adjusted incidence risk ratio: 1.29, 95% CI: 1.19, 1.40) of flares over 12 months in multivariate analyses.

CONCLUSIONS

Baseline US findings indicating MSU deposits and US-detected inflammation are independent predictors of gout flares over 12 months.

Establishment and Validation of Predictive Model of Tophus in Gout Patients

(1) Background: A tophus is a clinical manifestation of advanced gout, and in some patients could lead to joint deformities, fractures, and even serious complications in unusual sites. Therefore, to explore the factors related to the occurrence of tophi and establish a prediction model is clinically significant. (2) Objective: to study the occurrence of tophi in patients with gout and to construct a predictive model to evaluate its predictive efficacy. (3) Methods: The clinical data of 702 gout patients were analyzed by using cross-sectional data of North Sichuan Medical College. The least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression were used to analyze predictors. Multiple machine learning (ML) classification models are integrated to analyze and identify the optimal model, and Shapley Additive exPlanations (SHAP) interpretation was developed for personalized risk assessment. (4) Results: Compliance of urate-lowering therapy (ULT), Body Mass Index (BMI), course of disease, annual attack frequency, polyjoint involvement, history of drinking, family history of gout, estimated glomerular filtration rate (eGFR), and erythrocyte sedimentation rate (ESR) were the predictors of the occurrence of tophi. Logistic classification model was the optimal model, test set area under curve (AUC) (95% confidence interval, CI): 0.888 (0.839-0.937), accuracy: 0.763, sensitivity: 0.852, and specificity: 0.803. (5) Conclusions: We constructed a logistic regression model and explained it with the SHAP method, providing evidence for preventing tophus and guidance for individual treatment of different patients.

Infected nasal gout tophus: A case report

Gout is a common form of inflammatory arthritis, characterized by the deposition of monosodium urate crystals. If chronically present and not adequately treated by serum urate reducers, gout tophi can develop at various locations. Here, we report the first infected gout tophus at the septal cartilage and nasal tip.

Retrospective longitudinal assessment of ultrasound gout lesions using the OMERACT semi-quantitative scoring system

OBJECTIVES

The objectives of this study were (i) to evaluate the responsiveness of gout-specific US lesions representing urate deposition in patients receiving treat-to-target urate-lowering therapy using a binary and the OMERACT-defined semi-quantitative scoring systems; (ii) to determine the most responsive US measure for urate deposition and the optimal joint/tendon set for monitoring this.

METHODS

US (28 joints, 14 tendons) was performed in microscopically verified gout patients initiating/increasing urate-lowering therapy and repeated after 6 and 12 months. Static images/videos of pathologies were stored and scored binarily and semi-quantitatively for tophus, double contour sign (DC) and aggregates. Lesion scores were calculated at patient level, as were combined crystal sum scores. Responsiveness of lesions-scored binarily and semi-quantitatively-was calculated at both patient and joint/tendon levels.

RESULTS

Sixty-three patients underwent longitudinal evaluation. The static images/videos assessed retrospectively showed statistically significant decreases in tophus and DC, when scored binarily and semi-quantitatively, whereas aggregates were almost unchanged during follow-up. The responsiveness of the semi-quantitative tophus and DC sum scores were markedly higher than when using binary scoring. The most responsive measure for urate deposition was a combined semi-quantitative tophus-DC-sum score. A feasible joint/tendon set for monitoring included knee and first-second MTP joints and peroneus and distal patella tendons (all bilateral), representing the most prevalent and responsive sites.

CONCLUSION

The OMERACT consensus-based semi-quantitative US gout scoring system showed longitudinal validity with both tophus and DC being highly responsive to treatment when assessed in static images/videos. A responsive US measure for urate deposition and a feasible joint/tendon set for monitoring were proposed and may prove valuable in future longitudinal studies.

Dual-energy CT assessment of rapid monosodium urate depletion and bone erosion remodelling during pegloticase plus methotrexate co-therapy

OBJECTIVES

Pegloticase rapidly lowers serum urate in uncontrolled/refractory gout patients, with ≥1 tophus resolution in 70% of pegloticase responders and 28% of non-responders. Dual-energy computed tomography (DECT) non-invasively detects MSU deposition, including subclinical deposition, quantifies MSU volumes and depicts bone erosions. This report presents DECT findings in MIRROR open-label trial participants receiving pegloticase+MTX co-therapy.

METHODS

Serial DECT scans were obtained during pegloticase (8 mg biweekly infusions)+oral MTX (15 mg/week) co-therapy. Bilateral hand/wrist, elbow, foot/ankle and knee images were analysed with default post-processing settings. MSU volumes were quantified and bone erosions were identified and evaluated for remodelling (decreased size, sclerosis, new bone formation). DECT and physical examination findings were compared.

RESULTS

2 patients underwent serial DECT. Patient 1 (44-year-old male) completed 52 weeks of pegloticase+MTX co-therapy (26 infusions). Baseline examination detected 4 tophus-affected joints while DECT identified 73 MSU-affected joints (total MSU volume: 128.76 cm3). At end-of-treatment, there were no clinically-affected joints and 4 joints with DECT-detected MSU deposition. MSU volume decreased by 99% and bone erosion remodelling was evident. Patient 2 (51-year-old male) had 10 weeks of therapy (5 infusions), discontinuing because of urate-lowering response loss. Baseline examination detected 7 tophus-affected joints while DECT identified 55 MSU-affected joints (total MSU volume: 59.20 cm3). At end-of-treatment, there were 5 clinically affected joints and 42 joints with DECT-detected MSU deposition. MSU volume decreased by 58% and bone erosion remodelling was evident.

CONCLUSION

DECT detected subclinical MSU deposition and quantified changes over time. Rapid tophus resolution and bone erosion remodelling occurred during pegloticase+MTX co-therapy.

TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT03635957.

Gouty Tophus in the Scrotum: An Unusual Extra-Articular Manifestation of Gout

Background: Gout is a chronic disorder caused by the deposition of monosodium urate crystals in soft tissues. Tophi are granulomatous inflammatory responses to the deposited crystals and manifest as subcutaneous nodules, typically in the first metatarsophalangeal joint but also in the olecranon bursa, Achilles tendon, ears, and finger pulps.

Case Report: A 56-year-old male presented to an outpatient clinic with an 8-month history of an expanding scrotal lesion. The patient had no significant family history but had a history of high blood pressure and gout, diagnosed at age 24 years, without current treatment. Excisional biopsy from the ulcerated area of the scrotum was performed for confirmatory diagnosis, and pathology reported gouty tophus.

Conclusion: To our knowledge, this case is the first report of a scrotal manifestation of gouty tophus and the second of genital involvement. Awareness of the possibility of genital manifestations of this disease is important because although gouty tophi are rare, they can present in patients with long-term uncontrolled gout.

Repair of tophus wound of the heel with sural nerve nutrition flap with peroneal artery perforating branch: a retrospective study

BACKGROUND

This study was to investigate the clinical effect of a sural nerve nutrition flap with peroneal artery perforator for repairing tophus wound of the heel.

METHODS

Over a 5-year period, 7 elderly male patients with tophus ulceration of the heel were admitted with exposed Achilles' tendon, and a chronic unhealed wound. Debridement, expansion and vacuum sealing drainage (VSD) lavage were performed initially, with simultaneous uric acid-lowering treatment. A 4×6-8×10 cm sural nerve nutrition flap with peroneal artery perforator was the secondary repair after further debridement of the wound. Preoperative Doppler ultrasound located the penetrating point of the peroneal artery perforator as the rotation point of the flap, and the line between the midpoint of the Achilles' tendon and the lateral malleolus and the midpoint of the popliteal fossa 5° above the front of Achilles' tendon was the axis. The patients were treated postoperatively with anti-inflammatory, anticoagulant and spasmolytic drugs and other rehydration therapy, and allopurinol was continued to control uric acid. The blood supply and temperature of the flap and wound healing were monitored.

RESULTS

All 7 flaps survived completely after operation, with 1 case of postoperative wound discharge that finally healed after dressing change and 1 case of skin flap redness and swelling, which improved after strengthening anti-infection treatment. All 7 patients were followed up for 6-12 months (average 10 months). The skin flaps were soft in texture, with good color and appearance, and no recurrence of ulceration. The dorsal extension and plantar flexion of the ankle joint were good, and function was satisfactory.

CONCLUSIONS

The sural nerve nutrition flap with peroneal artery perforator has double blood supply, strong anti-infective ability, relatively fast tissue healing process, simple operation and high survival rate, making it ideal for repairing tophus wounds of the heel.

Post-ACL Reconstruction Graft Failure in Severe Gout Arthritis Patient

Introduction

Pain and instability following an anterior cruciate ligament (ACL) reconstruction remain a significant issue. Common causes include infection and inflammation, and mechanical issues such as graft failure.

Case Presentation

A 36-year-old male with an ACL reconstruction six years prior was admitted due to pain and swelling. The ACL graft that had ruptured was found arthroscopically. Numerous gout crystals and tophus were observed inside. This finding is suggested as a cause of this kind of complication.

Discussion

Biological failure is one of the causes of graft failure. Gout arthritis is associated with internal derangement of the joint structures, which is reported in advanced case.

Conclusion

Severe gouty arthritis, even though rare, could be an etiology of graft failure following ACL reconstruction and cause significant morbidity.

Assessing the sensitivity to change of the OMERACT ultrasound structural gout lesions during urate-lowering therapy

Objectives

To evaluate the sensitivity to change of ultrasound structural gout lesions, as defined by the Outcome Measures in Rheumatology (OMERACT) ultrasound group, in patients with gout during urate-lowering therapy (ULT).

Methods

Ultrasound (28 joints, 26 tendons) was performed in patients with microscopically verified gout initiating or increasing ULT and repeated after 3 and 6 months. Joints and tendons were evaluated by ultrasound for presence of the OMERACT structural gout lesions—double contour sign (DC), tophus, aggregates and erosion—scored binarily. A sum score was calculated at patient and lesion level. Changes at 3 and 6 months in patient sum scores and lesion scores at different locations were evaluated.

Results

50 patients (48 men), mean age 68.9 (range, 30–88) years, were included. Ultrasound showed a statistically significant decrease in DC and tophus sum scores from 0 months (3.16 and 2.68, respectively) to 3 months (2.33 and 2.43) and 6 months (1.34 and 1.83) (all p<0.002). The aggregate sum score only decreased significantly from 3 to 6 months (6.02 to 5.02, p=0.002), whereas erosion sum score remained almost unchanged. All four structural lesions were most commonly found in metatarsophalangeal (MTP) 1 joints (>1 lesions bilaterally), and furthermore MTP2–4 and knee joints were common sites especially for DC. Likewise, these regions were the locations with most pronounced changes in scores.

Conclusion

Ultrasound assessment of the OMERACT structural gout lesions scored binarily seems to be a useful tool for monitoring urate depositions during ULT. Particularly DC and tophus showed sensitivity to change after only 3 months of treatment.

[Gout affecting the hip in a 57-year-old woman: case report]

Cette étude rapporte le cas d'une arthrite goutteuse de la hanche, décrite chez une femme de 57 ans, diabétique et hypertendue, sans antécédents de goutte et qui a consulté pour douleur chronique de la hanche droite. L´examen clinique a trouvé une patiente obèse, marchant avec une boiterie droite douloureuse en rapport avec flessum de la hanche homolatérale. La radiographie standard a montré des formations ostéo-condensantes en regard de la face antérieure du col fémoral. La biologie se résume en un syndrome inflammatoire avec un taux normal d´acide urique. La tomodensitométrie et l'imagerie par résonance magnétique (IRM) nous ont orientés vers une chondromatose de la hanche. La patiente a eu un traitement chirurgical avec exérèse complète d´une formation friable et arthrolyse de la hanche. Les prélèvements bactériologiques n´ont pas isolé de germe et l´étude anatomopathologique a conclu à une goutte de la hanche. Un traitement médical à base de Colchicine a été introduit. L´évolution a été marquée par une régression complète du flessum, disparition de la boiterie et amélioration des douleurs de la hanche de façon satisfaisante.

[CME: Gout Ulcer: An Underrecognized Cause of Leg Ulcer and Its Most Common Differential Diagnosis]

CME: Gout Ulcer: An Underrecognized Cause of Leg Ulcer and Its Most Common Differential Diagnosis Abstract. In addition to the differential diagnosis of the leg ulcer, an entity hardly mentioned in the literature is considered, namely the gout ulcer. On the basis of a case study, newer forms of diagnosis and their significance in case of suspicion of gout ulcer are discussed.

Relationship between urate within tophus and bone erosion according to the anatomic location of urate deposition in gout: A quantitative analysis using dual-energy CT volume measurements

The aim of this study was to measure the urate volume within tophus and bone erosion volume using dual-energy computed tomography in patients with tophaceous gout. Furthermore, our study aims to quantitatively analyze the relationship between monosodium urate (MSU) crystal deposition and bone erosion according to the anatomic location of urate deposition.Seventy-seven subjects with chronic gout were positively identified for the presence of urate deposition. Only 27 subjects identified for the presence of urate in contact with bone erosion were included in this study. The urate volumes and associated erosion volumes were measured. The relationships between urate within tophus and bone erosion were separately analyzed according to the anatomic location of urate deposition.Twenty-seven subjects were all male (100%) with a median (interquartile range, IQR) age of 52 (45-61) years. From all the subjects, 103 tophi depositions were identified in contact with bone erosion, including 58/103 tophi that contained an intraosseous component and 45/103 nonintraosseous tophi. Tophi containing intraosseous components were larger than nonintraosseous tophi (urate volume: median [IQR] 45.64 [4.79-250.89] mm vs 19.32 [6.97-46.71] mm, P = .035) and caused greater bone erosion (erosion volume: 249.03 [147.08-845.33] mm vs 69.07 [32.88-111.24] mm, P < .001). Almost all erosion volumes were larger than urate volumes in nonperiarticular tophi, in contrast to most erosion volumes, which were less than urate volumes in the tophi that contained a periarticular component (odds ratio, 95% confidence interval: 74.00, 14.70-372.60; P < .001). Urate volume and erosion volume demonstrated positive correlations in intraosseous tophi, intraosseous-intra-articular-periarticular tophi, and intraosseous-intra-articular tophi (rs = 0.761, rs = 0.695, rs = 0.629, respectively, P < .05).MSU crystal deposition shows a promoting effect on the development of bone erosions in varying degrees, associated with the location of MSU crystals deposited in the joints. The intraosseous tophi contribute the most to bone erosions, followed by intra-articular tophi, and periarticular tophi.

[Gout - a treatable condition]

Gout is a disabling and common arthritis with increasing prevalence. Without treatment the disease can cause permanent joint damage. It is commonly associated with the metabolic syndrome but can also be related to a number of life-threatening diseases and their treatments. Gout is often misdiagnosed and its long-term management is suboptimal despite the availability of effective treatments. Recently The American College of Rheumatology (ACR) and European League against Rheumatism (EULAR) released common guidelines for the diagnosis of gout and EULAR updated their guidelines for management. There is increased emphasis on preventive treatment, both with lifestyle modifications and pharmacotherapy. It is important to educate patients about the disease and the existence of effective treatment options, how to manage an acutely inflamed joint and why it is important to lower serum urate. When a patient is diagnosed with gout he should be screened for associated comorbidities. It is important to treat-to-target and lower serum urate over a long period of time to induce permanent remission of gouty arthritis.

Case with long-standing gout showing various ultrasonographic features caused by monosodium urate monohydrate crystal deposition

Gout, which is characterized by the deposition of monosodium urate monohydrate (MSU) in the synovial fluid and other tissues, is the most common form of inflammatory arthritis. Unlike the easily recognized acute and monoarticular gouty arthritis, advanced gout induces multiple finger joint disorders and may sometimes mimic rheumatoid arthritis (RA) or vice versa. The gold standard for gout diagnosis is the identification of MSU crystals via aspiration in the symptomatic joints or nodules; however, its feasibility and specificity may be inadequate. Recently, there have been important advances in imaging techniques, assisting in the non-invasive diagnosis of gout. Ultrasonography (US) has been known to have the ability to detect deposition of MSU crystals in patients with gout. Herein, we report an evocative case of long-standing gout with precisely detected specific US features indicating MSU crystal deposition and inflammation in multiple joints. Comprehensive US assessment included the bone, hyaline cartilage, soft tissue, subcutaneous nodules and tendon; we also discriminated gouty arthritis from RA.

Joint Clinical Consensus Statement of the American College of Foot and Ankle Surgeons® and the American Association of Nurse Practitioners®: Etiology, Diagnosis, and Treatment Consensus for Gouty Arthritis of the Foot and Ankle

Gout is a condition that commonly affects the foot and ankle, and practitioners who treat these structures should be aware of the methods to diagnose and treat this form of arthritis. Practitioners also need to recognize extra-articular manifestations of the disease. Although the acutely red, hot, swollen joint is a common presentation, chronic tophaceous gout can be associated with pain, nodule formation, and cutaneous compromise. Since the underlying causes that lead to excessive monosodium urate deposition may be treatable, early and accurate diagnosis can be very beneficial and may even prevent articular degeneration.

Atypical musculoskeletal manifestations of gout in hyperuricemia patients

Deposition of tophus is a common feature in chronic gout; however, signs and symptoms are not always well-pronounced in cases of uncommon sites. We report a case series of three patients, one with an acute locked knee suspected to be meniscus tear or intra-articular loose body, a second case with a lump on the dorsal hand suspected to be a benign lesion, and a third case with a finger flexion deformity with carpal tunnel syndrome; all three cases were later on found out to be tophaceous gout. White chalky monosodium urate crystal deposition was found to be the culprit of the symptoms of the patients.

A Case of a Second Intermetatarsal Space Gouty Tophus with a Presentation Similar to a Morton's Neuroma

Non-infectious soft tissue lesions of the foot and ankle are relatively rare clinically. These include benign and malignant neoplasms, as well as non-neoplastic or pseudotumoral lesions such as ganglionic, synovial and epidermoid cysts, intermetatarsal and adventitious bursitis, inflammatory lesions like gouty tophi and rheumatoid nodules, Morton’s neuroma, and granuloma annulare.

A 48-year-old male with a history of medically treated tophaceous gout presented with left foot neuropathic pain and paresthesia, in the setting of a well-circumscribed soft tissue lesion of the second intermetatarsal space, suspected to be a Morton’s neuroma. Magnetic resonance imaging (MRI) showed a 4.1 x 2.7 x 2.6 cm heterogeneous soft tissue mass containing multiple cystic areas. Excisional biopsy was performed and histologic examination revealed well-circumscribed nodules of amorphous material containing needle-shaped clefts, rimmed by histiocytes, and multinucleated giant cells consistent with a gouty tophus.

This is the first case reported in the literature of an intermetatarsal gouty tophus causing neuropathic pain and paresthesia. While Morton’s neuroma is the most common cause of this presentation, this case illustrates that other pseudotumoral lesions, such as a gouty tophus, may present similarly, and should be considered in the differential diagnosis. While most cases of tophaceous gout can be adequately treated with urate-lowering therapy, surgery may be indicated for tophi that do not resolve with medical treatment based upon symptom severity, compression of nearby structures, and functional impairment.

An optimal ultrasonographic diagnostic test for early gout: A prospective controlled study

Objective

To identify the optimal sites for classification of early gout by ultrasonography.

Methods

Sixty patients with monosodium urate crystal-proven gout (25 with early gout [≤2-year symptom duration], 35 with late gout [>2-year symptom duration], and 36 normouricemic healthy controls) from one centre were prospectively evaluated. Standardized blinded ultrasound examination of 36 joints and the triceps and patellar tendons was performed to identify tophi and the double contour (DC) sign.

Results

Ultrasonographic sensitivity was lower in early than late gout. Binary logistic regression analysis showed that two ultrasonographic signs (tophi in the first metatarsophalangeal joint [odds ratio, 16.46] and the DC sign in the ankle [odds ratio, 25.18]) significantly contributed to the final model for early gout diagnosis (sensitivity and specificity of 84% and 81%, respectively). The inter-reader reliability kappa value for the DC sign and tophi was 0.712.

Conclusions

Four-joint investigation (both first metatarsophalangeal joints for tophi and both ankles for the DC sign) is feasible and reliable and could be proposed as a screening test for early ultrasonographic gout classification in daily practice.

Acute Posterior Tarsal Tunnel Syndrome Caused by Gouty Tophus

Gouty tophus of the tarsal tunnel is a rare cause of posterior tarsal tunnel syndrome. We present a case of acute posterior tarsal tunnel syndrome due to gouty tophus that required early tarsal tunnel release in order to avoid irreversible nerve damage. The presence of background neuropathy resulted in a less favorable result than expected.

LEVELS OF EVIDENCE

Therapeutic, Level V: Case report.

Imaging in gout: A review of the recent developments

Gout is a common inflammatory arthritis and is caused by accumulation of monosodium urate crystals in joints and soft tissues. Apart from joint damage, untreated gout is associated with cardiovascular and renal morbidity. Gout, whilst in principle considered to be well understood and simple to treat, often presents diagnostic and management challenges, with evidence to suggest that it is often inadequately treated and poor compliance is a major issue. Imaging tools can aid clinicians in establishing the correct diagnosis, when histological crystal diagnosis is unable to be established, and also assess the burden of inflammatory and structural disease. Imaging can also be used to monitor treatment response. The imaging techniques that currently have a role in the imaging of gout include conventional radiography, ultrasound, computed tomography, dual energy computed tomography, magnetic resonance imaging and nuclear medicine. Despite the lack of major technological advances in imaging of gout in recent years, scientific studies of existing imaging modalities have improved our understanding of the disease, and how to best utilize imaging techniques in the clinical setting.

A case of mitral valve tophus in a patient with severe gout tophaceous arthritis

A few cases of cardiac valve tophi have been reported in literature. In this case report, the echocardiographic characteristics of the hyperechoic mass in the posterior leaflet mitral valve, intact mitral valve ring, and the occurrence of severe tophaceous gout arthritis suggested the diagnosis of a gout tophus on the mitral valve.