Investigation on monosodium urate deposition in the first metatarsophalangeal joint and ankle of primary gout patients using dual-energy computed tomography.

BACKGROUND: Gout is caused by deposition of monosodium urate (MSU) crystals. One of the tools of choice to identify MSU crystals is the Dual-Energy Computed Tomography (DECT). This study aims to determine MSU crystal deposition using DECT by comparing its detection in the first metatarsophalangeal joints (MTPJ) with that in the ankles, as well as to analyse the association between the crystal deposition and anthropometrics, clinical characteristics, and serum biochemical levels of a primary gout patient. MATERIALS AND METHODS: This cross-sectional study included patients (n = 94) from the Clinic Hoa Hao Medic Medical Centre in Vietnam, who were diagnosed with primary gout with pain/swelling of at least one ankle or first MTPJ. DECT of both joints was used to identify MSU. Statistical analyses were performed using the Student's t-test, Wilcoxon ranksum, Pearson's chi-square, and Spearman's tests. RESULTS: Approximately 80% had MSU crystal deposition in the ankle and/or first MTPJ with no significant difference in deposition between the two joints. MSU deposition was significantly associated with disease duration (p = 0.003), flare-ups (p = 0.006), and cut-off of 6 weeks' duration (p = 0.006), bone erosion (p = 0.006), and palpable tophi (p = 0.003). There was no association between MSU deposition with age, body mass index (BMI), hypertension, serum levels of uric acid (UA), creatinine, high-sensitive C-reactive protein (hsCRP), total cholesterol (C-total), and triglyceride (TG). CONCLUSIONS: MSU deposition occurred in both ankle and first MTP at the same rate. The deposition was associated with disease duration and flare-ups. Prevention of flare-ups seems helpful to limit MSU crystal deposition.

Medially positioned plate in first metatarsophalangeal joint arthrodesis.

OBJECTIVE: The purpose of this study was to biomechanically compare the stability of first metatarsophalangeal (MTP1) joint arthrodesis with dorsally and medially positioned plates. METHODS: A physical model of the MTP1 joint consists of printed synthetic bones, a titanium locking plate and screws. In the experiments, samples with dorsally and medially positioned plates were subjected to loading of ground load character in a universal testing machine. Force-displacement relations and relative displacements of bones were recorded. The obtained results were used to validate the corresponding finite element models of the MTP1 joint. Nonlinear finite element simulations of the toe-off phase of gait were performed to determine the deformation and stress state in the MTP1 joint for two positions of the plate. RESULTS: In numerical simulations, the maximum displacement in the dorsal direction was noticed at the tip of the distal phalanx and was equal to 19.6 mm for the dorsal plate and 9.63 mm for the medial plate for a resultant force of 150 N. Lower relative bone displacements and smaller plastic deformation in the plate were observed in the model with the medial plate. Stress values were also smaller in the medially positioned plate and locking screws compared to fixation with the dorsal plate. CONCLUSIONS: A medially positioned locking plate provides better stability of the MTP1 joint than a dorsally positioned plate due to greater vertical bending stiffness of the medial plate. Smaller relative bone displacements observed in fixation with the medial plate may be beneficial for the bone healing process. Moreover, lower stress values may decrease the risk of complications associated with hardware failure.

Risk factors of ultrasound-detected tophi in patients with gout.

INTRODUCTION: Tophus is a characteristic manifestation of advanced gout, the clinical significance of which is often underestimated. This study aimed to compare the difference of clinical and ultrasound features between gout patients with and without ultrasound-detected tophus and identify risk factors associated with the presence of ultrasonographic tophus in gout patients. MATERIALS AND METHODS: A total of 85 gout patients were divided into tophaceous (n = 54) and non-tophaceous group (n = 31) according to the presence of ultrasound-detected tophus. All patients underwent ultrasound examination of the bilateral knee, ankle, and first metatarsophalangeal joint (MTP1). Clinical information and ultrasound findings were compared between the groups. A multivariate logistic regression analysis to determine possible risk factors is associated with the number of ultrasound-detected tophaceous joints. RESULTS: Older age, longer gout duration, higher gout flare frequency, lower estimated glomerular filtration rate (eGFR), and higher prevalence of hypertension, hyperlipidemia, and ultrasound manifestations including double contour sign (DCS) and erosion were observed in tophaceous patients from the univariate analysis. Multivariable logistic regression analysis showed that eGFR and disease duration were independently associated with the number of tophaceous joints. Lower eGFR and longer course duration were associated with a higher risk of tophi (B = -0.020, 0.141; P = 0.009, 0.010, respectively). CONCLUSIONS: The main factors that may influence the formation of tophi are disease duration and eGFR.Key Points• Lower eGFR and longer course duration are independent risk factors of tophi formation in gout patients.• The incidence of ultrasound manifestations including double contour sign (DCS) and erosion in patients with tophi were higher than those without tophi.

Risk factors for the formation of double-contour sign and tophi in gout.

BACKGROUND: This study aimed to confirm the diagnostic accuracy of ultrasound (US) on gout and explore the potential risk factors for double-contour sign and tophi formation in gout patients. METHODS: The US analyses were performed on all knee, ankle, and first metatarsophalangeal (MTP 1) joints to reveal the type and location of lesions. While a questionnaire and blood biochemical index were used to explore the potential risk factors for double-contour sign and tophi in gout, the SPSS17.0 software was used for statistical analysis in the present study. RESULTS: Totally, 117 gout patients with 702 joints (38 lesions in knee joint, 93 lesions in ankle joint, and 112 lesions in MTP 1 joint) were enrolled in current analyses. Double-contour sign and joint effusion were the two most outstanding lesion manifestations in knee joints and ankle joints. Tophi and double-contour sign were the two most outstanding lesion manifestations in TMP 1 joints. Moreover, factors including uric acid (UA) level and the highest blood UA were potential risk factors of the double-contour sign, while age and history of US were potential risk factors for tophi. CONCLUSION: US was effective on the joints of gout patients. There was US sensitivity for tophi and double-contour sign in MTP 1 joints. The double-contour sign was a potential specific manifestation in knee joints and ankle joints. Furthermore, UA and highest blood UA level were potential risk factors for double-contour sign, while age and US history were potential risk factors for tophi.

Temporal evolution of urate crystal deposition over articular cartilage after successful urate-lowering therapy in patients with gout: An ultrasonographic perspective.

OBJECTIVE: To detect evolution of ultrasonographic signs of deposition of monosodium urate crystals (MSUC) in gouty joints by serial ultrasonography after initiation of urate-lowering therapy (ULT). METHODS: Adult gout patients were examined by serial ultrasonography after initiation of ULT with target serum uric acid (SUA) < 6 mg/dL. RESULTS: Thirty-eight male patients with gout with mean age of 50 ± 11 years, median disease duration of 48 months and baseline mean SUA level of 8.8 ± 1.5 mg/dL were recruited. Ultrasonographic evidence of MSUC deposition was detected in 89.74% of first metatarsophalangeal (MTP) joints and 27.63% of knee joints. Double contour sign (DCS), tophi, and hyperechoic spots (HES) were detected in 77.63%, 43.42%, and 19.74% of first MTPs, respectively. SUA level normalizes and plateaus after fourth month of follow-up. DCS thickness reduced significantly throughout the follow-up period. Overall, 86.25% DCS and 100% HES disappeared with median time of 6 months and 5.7 months, respectively. SUA normalization was the only significant predictor of DCS disappearance. CONCLUSIONS: Serial ultrasonographic determination of DCS, tophi, or HES during hypouricemic therapy is a noninvasive, effective method to detect the lowering of burden of urate load in gouty joints.

The first metatarsophalangeal joint in gout: a systematic review and meta-analysis.

BACKGROUND: The aim of this review was to qualitatively synthesise studies that have investigated characteristics of the first metatarsophalangeal joint (1(st) MTP) in gout and to undertake a meta-analysis to estimate the average prevalence of acute 1(st) MTP arthritis across studies in people with gout. METHODS: Studies published in English were included if they involved participants who had a diagnosis of gout and presented original findings relating to the following outcome measures associated with the 1(st) MTP: epidemiology; clinical features; structural and functional characteristics; and microscopic and imaging features. RESULTS: Forty-five studies were included in the qualitative synthesis. 1(st) MTP pain was a prominent feature in people with gout. People with 1(st) MTP gout reported walking- and general-disability. Structural and functional characteristics of 1(st) MTP gout included hallux valgus, osteoarthritis, and restricted joint motion. Successful crystal aspiration ranged from 81 to 91 % and positive crystal identification via microscopy ranged from 83 to 93 % in patients with a history of 1(st) MTP gout. Imaging features were common at the 1(st) MTP including the double contour sign, tophi and erosions. Eleven studies involving 2,325 participants were included in the meta-analysis, providing an estimate of the average prevalence of acute 1(st) MTP arthritis across studies of 73 % (95 % prediction interval 40-92 %; range 48-97 %; I(2) = 93 %). CONCLUSIONS: 1(st) MTP acute arthritis is highly prevalent in people with gout and has a substantial impact on patient-reported pain and disability. Gout affects the structure and function of the 1(st) MTP. Microscopic and imaging studies have demonstrated crystal deposition and joint damage at the 1(st) MTP in people with gout.

Scintigraphic evaluation of metacarpophalangeal and metatarsophalangeal joints in clinically sound horses.

The purpose of this study was to describe the pattern of radiopharmaceutical uptake in the metacarpophalangeal (MCP) and metatarsophalangeal (MTP) (fetlock) joints in clinically sound horses. Scintigraphic images from 29 clinically normal horses were evaluated. All the images were assessed subjectively. The lateral views were assessed quantitatively using vertical line profiles through the center of the joint, and mean ratios of radiopharmaceutical uptake were calculated from regions of interest around the third metacarpal or metatarsal bones, and the proximal phalanx and proximal sesamoid bones. From the vertical line profiles, in the majority of forelimbs (65%) the peak activity of radiopharmaceutical distribution was at the proximal region of the proximal phalanx, with a significantly lower activity within the condyles of the third metacarpal bone. However, in 84% of hindlimbs there was a broader profile peak incorporating the condyles of the third metatarsal bone and the proximal aspect of the proximal phalanx, indicating a more generalized even uptake of radiopharmaceutical across the MTP joint. When the regions of interest were compared between front and hindlimbs, there was no significant difference between proximal phalanx and proximal sesamoid bones, but the distal condyles of the third metacarpal bone of the forelimb had significantly lower radiopharmaceutical activity than hindlimbs (P < 0.04). In lateral images, the mean forelimb ratios tended to be higher in the left MCP joint compared with the right (P = 0.069). In hindlimbs, the mean ratios tended to be higher in the right MTP joint than the left (P = 0.052). There was no significant effect of age.

1997 William J. Stickel Gold Award. Morphological and biochemical properties of metatarsophalangeal joint cartilage.

Although there is sparse information concerning the properties of foot-joint cartilages, knowledge of the morphology and biochemistry of these cartilages is important in the study of changes that occur in the development of osteoarthritis. Normal first and fifth metatarsophalangeal joints were chosen for comparison because of the difference between these two joints in the prevalence of osteoarthritis, particularly with advancing age. The authors' study shows that there is no age-related decrease in articular-cartilage thickness; however, there is an age-related decrease in the chondrocyte density in the superficial zone in both joints. There is, however, a difference between the two joints in the level of expression of matrix-degrading enzymes. This difference may indicate differences in specific chondrocyte activity that precedes or accompanies the development of osteoarthritis or other degenerative morphological changes.

Subcutaneous pancreatic fat necrosis associated with acute arthritis.

Subcutaneous fat necrosis is a well described, rare sequela of acute pancreatitis. Uncommonly, arthritis is seen in association with these 2 disease processes. We report a case of fulminant pancreatitis presenting as an acute arthritis. Birefringent crystal-like structures led to initial diagnostic confusion with gout.

Seudopodagra, presentación de cuatro casos y revisión de la literatura

Se presentan cuatro casos de mujeres jóvenes con cuadro clínico de inflamación aguda de la primera articulación metatarsofalángica y a quienes se les demostró en los rayos X calcificaciones a ese nivel. Consideramos que se trata de los primeros cuatro casos de suedopodagra por hidroxiapatita descritos en Colombia. Se hace una descripción yel diagnóstico diferencial de esta entidad

Crystal deposition in the knee and great toe joints of asymptomatic gout patients.

Crystal deposition in asymptomatic knee and first metatarsophalangeal (MTP) joints has been studied in 31 patients with previously proven gout. All had had clinical gout in their MTP joints but their knee joints had never been the site of acute gout. Knee arthroscopy was performed permitting synovial membrane inspection, photography and biopsy. Crystalline material was seen in 9 knees (28%) and confirmed histologically as monosodium urate (MSU) in 4 (12.5%). Synovial fluid analysis on 26 samples using a polarizing light microscope demonstrated MSU crystals in 4 (12.5%) and calcium pyrophosphate dihydrate (CPPD) in 2 (6%). Fluid aspirated from 27 of the metatarsophalangeal joints revealed MSU crystals in 14 (52%) and no CPPD crystals.

Distribution of immunoreactive fibronectin and collagen (type I, III, IV) in mouse joints. Fibronectin, an essential component of the synovial cavity border.

Hyaluronic acid traditionally has been held to play a major role in the control of transsynovial exchanges and in the biomechanical properties of synovial fluid and cartilage surfaces. As with previous ultrastructural observations, immunohistochemical data show that a more complex differentiation must be envisaged for interstitial tissues bordering the synovial cavity. In particular, the elective concentration of fibronectin in the lining layer of the synovial membrane and its presence as a fine layer at the articular cartilage surfaces indicate that this glycoprotein, along with hyaluronic acid, may play an important role in joint physiology. Only immunoreactivity for type III procollagen is diffusely distributed in the entire synovial membrane and, in addition, is found associated with fibronectin immunoreactivity at the articular cartilage surfaces.

Aspiration of the asymptomatic metatarsophalangeal joint in gout patients and hyperuricemic controls.

Asymptomatic metatarsophalangeal joints were aspirated in a group of patients with gout, in 2 control groups with hyperuricemia, and in 1 normouricemic control group. Extracellular urate crystals were present in 70% of gout patients, in 1 of 19 patients with asymptomatic hyperuricemia, and in 2 of 9 patients with renal failure and hyperuricemia but no history of joint disease. Crystals were not found in the 10 normouricemic patients who had other types of arthritis. The presence of crystals in the subjects with gout was not correlated with a history of podagra, duration of gout, presence of tophi, or degree of control of hyperuricemia. Though crystals were found on rare occasions in joint fluid of asymptomatic hyperuricemic subjects, the presence of these crystals in asymptomatic joints was more common in subjects with gout.