Tripterine ameliorates monosodium urate crystal-induced gouty arthritis by altering macrophage polarization via the miR-449a/NLRP3 axis.

OBJECTIVE: Tripterine (Trip) is frequently applied to alleviate inflammation in various diseases such as rheumatoid arthritis. Macrophages have both anti-inflammatory and pro-inflammatory functions. However, whether Trip can inhibit cell inflammation in gouty arthritis (GA) remains undiscovered and whether the mechanism involved in macrophage polarization is also undetermined. This paper aims to study the effects of Trip on inflammation and macrophage polarization in GA. METHODS: Monosodium urate (MSU) crystals were used to establish GA mouse models, and bone marrow-derived macrophages (BMDMs) were induced to construct GA cell models. Pretreatments of Trip and injection of Antagomir-449a/Agomir-449a were performed on mice for 6 days. The effects of Trip and miR-449 on toe swelling, joint damage of GA mouse were examined. The alternations on cell morphology, cell proliferation marker Ki67, inflammatory cytokines, NLRP3 inflammasome, and NF-κB signaling-related proteins were also determined both in vivo and in vitro. Dual-luciferase reporter gene assay and RIP assay were adopted to estimate the targeting relationship between miR-449a and NLRP3. RESULTS: GA mouse model had increased M1 macrophage, intensified inflammation response, along with suppressed miR-449a expression. Following administration of Trip attenuated cell inflammation, promoted macrophage polarize to M2 phenotype, elevated miR-449a expression, repressed the phosphorylation levels of NF-κB signaling-related proteins, and diminished IκBα expression in vivo and in vitro. However, inhibition of miR-449a hindered the favorable effect of Trip on GA and increased NLRP3 inflammasome expression. MiR-449a directly targeted NLRP3. Overexpression of NLRP3 partially eliminated the biological effects of miR-449a agonist. CONCLUSION: Trip regulates macrophage polarization through miR-449a/NLRP3 axis and the STAT3/NF-κB pathway to mitigate GA. The elucidation on the molecular mechanism of Trip in GA may provide theoretical guidance for clinical therapy of GA.

Bone change after surgical treatment of mucous cyst at the interphalangeal joint of the great toe in a patient with rheumatoid arthritis.

Digital mucous cysts are a type of benign cysts of the digits, typically located at the distal interphalangeal joints or in the proximal nail fold, which usually occur on the hands. The diagnosis of digital mucous cysts is relatively easy because of its light-transmitting property, but the treatment is often difficult because of complications including recurrence, infection, diminished range of motion, and nail deformity. We report a case of rheumatoid arthritis (RA) showing good course after surgical treatment of mucous cyst at the interphalangeal joint of the great toe. In a case of RA, combination of synovectomy with surgical treatment of mucous cyst might be effective.

Dactylitis in enteropathic spondyloarthritis.

OBJECTIVES: Dactylitis has long been recognised as one of the significant features of spondyloarthropathies. In the literature, the prevalence of dactylitis in enteropathic spondyloarthritis (EASpA) ranges between 2% and 4%. The aim of this study was to identify the prevalence of dactylitis in EASpA patients and to investigate its association with clinical subset and with articular and bowel disease activity. METHODS: 78 EASpA patients and 78 controls were enrolled for this study. All patients and controls underwent a rheumatological and a gastroenterological clinical examination. Demographic and clinical features were recorded. Diagnosis of dactylitis was made by physical examination and was evaluated using the Leeds Dactylitis Instrument (LDI). RESULTS: In our study the prevalence of dactylitis in EASpA was 15.38%, mainly in patients with Crohn's disease (CD) and peripheral arthritis. A significantly higher articular and bowel disease activity was found in patients with dactylitis compared to those without it. The family history of psoriasis represented a predictor of occurrence of dactylitis. Finally, a significant correlation between disease activity and LDI score was found in EASpA. CONCLUSIONS: The results of our study showed a high prevalence of dactylitis in EASpA. It was more frequent in patients with CD and peripheral involvement with a higher articular disease activity, confirming that dactylitis may be a severity marker and a prognostic factor for EASpA. The significant correlation between disease activity and LDI score could address LDI as a potential tool of assessment of dactylitis.

High-resolution MRI assessment of dactylitis in psoriatic arthritis shows flexor tendon pulley and sheath-related enthesitis.

OBJECTIVE: Dactylitis is a hallmark of psoriatic arthritis (PsA) where flexor tenosynovitis is common. This study explored the microanatomical basis of dactylitis using high-resolution MRI (hrMRI) to visualise the small entheses around the digits. METHODS: Twelve patients with psoriatic dactylitis (4 fingers, 8 toes), and 10 healthy volunteers (6 fingers, 4 toes) had hrMRI of the digits using a 'microscopy' coil and contrast enhancement. All structures were evaluated including the tendons and ligaments, related enthesis organs, pulleys, volar/plantar plates and tendon sheaths. RESULTS: In dactylitis, collateral ligament enthesitis was seen in nine digits (75%), extensor tendon enthesitis in six digits (50%), functional enthesitis (5 digits, 42%), abnormal enhancement at the volar plates (2/5 joints, 40%) and the plantar plate (1/5 joints, 20%). Nine cases (75%) demonstrated flexor tenosynovitis, with flexor tendon pulley/flexor sheath microenthesopathy observed in 50% of all cases. Less abnormalities which were milder was observed in the normal controls, none of whom had any signal changes in the tendon pulleys or fibrous sheaths. CONCLUSIONS: This study provides proof of concept for a link between dactylitis and 'digital polyenthesitis' including disease of the miniature enthesis pulleys of the flexor tendons, further affirming the concept of enthesitis in PsA.

Accuracy of low-field magnetic resonance imaging versus radiography for guiding injection of equine distal interphalangeal joint collateral ligaments.

Desmopathy of the distal interphalangeal joint collateral ligament is a common cause of lameness in the horse and carries a variable prognosis for soundness. Intralesional treatment has been proposed for improving outcome; however, limited reports describe methods for injecting this ligament. The purpose of this study was to compare accuracy of low-field magnetic resonance imaging (MRI) vs. radiography for injecting the collateral ligament of the distal interphalangeal joint. Equine cadaver digit pairs (n = 10) were divided by random assignment to injection of the ligament by either technique. An observer unaware of injection technique determined injection success based on postinjection MRI and/or gross sections acquired from the proximal, middle, and distal portions of the ligament. McNemar's test was performed to determine statistical difference between injection techniques, the number of injection attempts, and injection of the medial or lateral collateral ligament. Magnetic resonance imaging guided injection was successful more frequently than radiographic-guided injection based on postinjection MRI (24 of 30 vs. 9 of 30; P = 0.0006) and gross sections (26 of 30 vs. 13 of 30; P = 0.0008). At each level of the ligament (proximal, middle, and distal), MRI-guided injection resulted in more successful injections than radiographic guidance. Statistical significance occurred at the proximal aspect of the collateral ligament based on postinjection MRI (P = 0.0143) and the middle portion of the ligament based on gross sections (P = 0.0253). Findings supported future testing of standing, low-field MRI as a technique for delivering intralesional regenerative therapy in live horses with desmopathy of these collateral ligaments.

MRI of hand and foot joints of patients with anticitrullinated peptide antibody positive arthralgia without clinical arthritis.

BACKGROUND: Anticitrullinated peptide antibodies (ACPA) and acute phase reactants may be increased before arthritis becomes clinically detectable, suggesting that the processes underlying rheumatoid arthritis (RA) start preclinically. Whether local inflammation occurs in the preclinical phase is unknown. Therefore, we studied the small joints of ACPA positive arthralgia patients for local subclinical inflammation. METHODS: Imaging was performed using 1.5 T extremity MRI. Painful hand or foot joints of 21 ACPA positive arthralgia patients without clinical arthritis were imaged. For comparison, hand and foot joints of 22 ACPA positive RA patients and 19 symptom free controls were studied. Within ACPA positive arthralgia patients, painful and symptom free joint regions were imaged. Scoring was performed according to the Outcome Measures in Rheumatology Clinical Trials (OMERACT) Rheumatoid Arthritis Magnetic Resonance Imaging Scoring (RAMRIS) method. Analyses were performed on joint region level and focused on inflammation (synovitis plus bone marrow oedema). RESULTS: The mean combined inflammation scores of the metacarpophalangeal/proximal interphalangeal joints of controls, painful joints of ACPA positive arthralgia patients and ACPA positive RA patients were 0.1, 0.7 and 3.7, respectively (p<0.001). Likewise, the mean combined inflammation scores of the wrist were 0.9, 2.3 and 10.3, respectively (p<0.001) and that of the metatarsophalangeal joints 0.5, 0.9 and 3.8, respectively (p=0.10). At the MCP joints, the combined inflammation score was significantly correlated with C reactive protein and erythrocyte sedimentation rate levels (rs=0.83 and rs=0.78, respectively) CONCLUSIONS: The present data suggest that local subclinical inflammation occurs in ACPA positive arthralgia patients.

Psoriatic arthritis mutilans (PAM) in the Nordic countries: demographics and disease status. The Nordic PAM study.

OBJECTIVE: To determine the prevalence and clinical characteristics of psoriatic arthritis mutilans (PAM) in the Nordic countries. METHOD: Patients with putative PAM aged ≥ 18 years were recruited. Fifty-nine patients were included after clinical examination. RESULTS: The prevalence of PAM in the adult Nordic population was estimated to be 3.69 per million inhabitants [95% confidence interval (CI) 2.75-4.63]. The female to male ratio was close to 1:1. The mean age of skin disease onset was 25 years and the mean age of onset of joint disease was 30 years. The onset of skin disease was 2 years earlier among female patients. At inclusion, the mean duration of arthritis was 27 ± 11 years for male patients and 33 ± 11 years for female patients. PAM was most frequently seen in the distal interphalangeal (DIP) joints of the toes, followed by the IP joint of the thumb and the DIP joint of the little finger on the left hand. Female and male patients had similar numbers of painful and swollen joints. Enthesitis was found in 19 patients (32%), while 38 patients (64%) had a history of dactylitis. Twenty-three of these 38 patients (61%) had a history of dactylitis in the same finger/toe as they had PAM. At the time of inclusion, 45% of the patients were found to have clear or almost clear skin. CONCLUSIONS: PAM in the Nordic countries has a low prevalence, with only three to five cases per million inhabitants. The majority of the patients present with mild skin disease.

[A woman in her thirties with pain in her fingers and toes]. / En kvinne i 30-årene med smerter i fingre og tær.

Hand pain is a relatively common complaint, and careful anamnesis and clinical examination may reveal its aetiology. Multiple joint involvement suggests either osteoarthritis or inflammatory arthritis. In the returning traveller, a more exotic explanation might be the case. A 31 year old woman was referred to our outpatient clinic for evaluation due to peripheral joint arthralgia. The symptoms started six months earlier, on the same day she returned from a three-week holiday in India. There were no signs of inflammatory arthritis or osteoarthritis. Blood tests were normal. Chikungunya virus serology was positive. The patient received symptomatic treatment with nonsteroid anti-inflammatory drugs and improved over a period of months. We describe the first case of Chikungunya fever diagnosed in our hospital.

Variations in chondrocyte apoptosis may explain the increased prevalence of osteoarthritis in some joints.

OBJECTIVES: To investigate whether there are any variations in chondrocyte susceptibility to an apoptotic stimulus between cells of articular cartilage (AC) from equine joints that differ in prevalence of osteoarthritis (OA). METHODS: Cartilage from macroscopically normal equine metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints was used. Prior to culture, chondrocyte viability was assessed using the fluorescein diacetate (FDA) and propidium iodide paravital staining method. AC explants were subsequently treated with tumour necrosis factor-α (TNF-α) in combination with Actinomycin D to induce apoptosis. Apoptosis of chondrocytes in cartilage sections was assessed by expression of active caspase-3 using indirect immunohistochemistry and sections also histologically graded using a 'modified' Mankin scoring system. RESULTS: Prior to culture (mean ± standard deviation) chondrocyte viability was 80.7% (3.5). The extent of chondrocyte apoptosis induced by TNF-α/Actinomycin D varied markedly according to the joint type that the cartilage was sampled from. For MCP joints, the extent of overall chondrocyte apoptosis was significantly higher (P < 0.001) in stimulated explants (26.7%, 10.3) than that observed in unstimulated control samples (9.6%, 7.5). Conversely, chondrocytes from PIP and DIP joint cartilage did not respond significantly to apoptotic stimulation (P > 0.05). Significant variations in cellularity and thickness were also evident between cartilages of different joint types. CONCLUSIONS: Data in this study demonstrate that chondrocytes from three equine joint types with varying prevalences of OA differ significantly in terms of susceptibility to apoptosis induction. This may provide a possible explanation for the joint-specific nature of the disease.

A report of a rare phalangeal periosteal chondroma of the foot.

Periosteal chondroma is a benign, slow-growing cartilaginous tumor that typically occurs at the metaphysis of long tubular bones beneath the periosteal membrane. A case is presented of a 42-year-old male who developed a firm, tender, uneven mass encircling the lateral, dorsal, and medial aspects of the right second proximal phalanx following a traumatic event. The mass was excised en toto and histopathologic findings are presented.

The cellular biology of flexor tendon adhesion formation: an old problem in a new paradigm.

Intrasynovial flexor tendon injuries of the hand can frequently be complicated by tendon adhesions to the surrounding sheath, limiting finger function. We have developed a new tendon injury model in the mouse to investigate the three-dimensional cellular biology of intrasynovial flexor tendon healing and adhesion formation. We investigated the cell biology using markers for inflammation, proliferation, collagen synthesis, apoptosis, and vascularization/myofibroblasts. Quantitative immunohistochemical image analysis and three-dimensional reconstruction with cell mapping was performed on labeled serial sections. Flexor tendon adhesions were also assessed 21 days after wounding using transmission electron microscopy to examine the cell phenotypes in the wound. When the tendon has been immobilized, the mouse can form tendon adhesions in the flexor tendon sheath. The cell biology of tendon healing follows the classic wound healing response of inflammation, proliferation, synthesis, and apoptosis, but the greater activity occurs in the surrounding tissue. Cells that have multiple "fibripositors" and cells with cytoplasmic protrusions that contain multiple large and small diameter fibrils can be found in the wound during collagen synthesis. In conclusion, adhesion formation occurs due to scarring between two damaged surfaces. The mouse model for flexor tendon injury represents a new platform to study adhesion formation that is genetically tractable.

Treatment of Dactylitis and Enthesitis in Psoriatic Arthritis with Biologic Agents: A Systematic Review and Metaanalysis.

OBJECTIVE: Biologic agents with different mechanisms of action [inhibitors of tumor necrosis factor-α (TNF-α), interleukin (IL)-12/23, and IL-17] showed efficacy in randomized controlled trials (RCT) in the treatment of psoriatic arthritis. We conducted a pooled metaanalysis of these agents for treatment of dactylitis and enthesitis and compared results with the American College of Rheumatology 20 (ACR20) response and Health Assessment Questionnaire-Disability Index (HAQ-DI) scores. METHODS: A systematic literature search was performed and a pooled metaanalysis of RCT with anti-TNF-α (infliximab, golimumab, adalimumab), anti-IL-12/23 (ustekinumab), and anti-IL-17 (secu kinumab, ixekizumab) was conducted using the random-effects model. Bias was assessed using the Cochrane risk-of-bias tool. RESULTS: Eighteen RCT were included in the pooled analysis (n = 6981). Both TNF-α inhibitors and novel biologics (ustekinumab, secukinumab, ixekizumab) demonstrated significant resolution of dactylitis at Week 24 with pooled risk ratios (RR) versus placebo of 2.57 (95% CI 1.36-4.84) and 1.88 (95% CI 1.33-2.65), respectively. For resolution of enthesitis at Week 24, RR for TNF-α inhibitors was 1.93 (95% CI 1.33-2.79) versus 1.95 (95% CI 1.60-2.38) for novel biologics. Both biologic categories showed overlapping ranges of ACR20 responses (TNF-α inhibitors: RR = 2.23, 95% CI 1.60-3.11; pooled IL-12/23 and -17: RR = 2.30, 95% CI 1.94-2.72) and similar quality of life improvement scores with mean HAQ-DI score changes of -0.29 (95% CI -0.39 to -0.19) and -0.26 (95% CI -0.31 to -0.22), respectively. CONCLUSION: The pooled analysis demonstrated that anti-TNF-α agents have the same efficacy as novel agents (ustekinumab, secukinumab, and ixekizumab) in dactylitis and enthesitis.

Lesions of the deep digital flexor tendon in the digit: a correlative MRI and post mortem study in control and lame horses.

REASONS FOR PERFORMING STUDY: Lameness associated with lesions of the deep digital flexor tendon (DDFT) in the digit is now recognised as an important cause of lameness, but there is currently limited information about the pathological nature of the lesions. OBJECTIVES: To compare: signal intensity changes on magnetic resonance images with histopathology; and histopathological changes in the DDFT from horses with no history of foot-related lameness (Group C) and horses with lesions of the DDFT confirmed using magnetic resonance imaging (MRI) (Group D). METHODS: Transverse sections of the DDFT were harvested from 3 sites in all horses: (1) immediately proximal to the navicular bursa (E1); (2) at the level of the navicular bone (E2); and (3) close to the tendon's insertion (E3). If lesions were identified at E1 or had been identified further proximally using MRI, additional sections were obtained until, in most cases, the proximal limit of the lesion was identified. All DDFTs were graded histopathologically using predefined criteria. The MR images were reviewed to determine the location and sequences in which increased signal intensity was seen. RESULTS: No haemorrhage or inflammatory cell infiltration was seen in any horse. At level E1, septal thickening, ghosting of blood vessels and blood vessel occlusion were common in Group D, but were not seen in Group C. Less commonly, there was core necrosis, only seen in Group D. At level E2, septal and vascular changes were most obvious in Group D. Core necrosis, dorsal splitting, crevicing and fibrillation were seen only in Group D. Septal and vascular changes were present in both Groups C and D at level E3, but fibrocartilaginous metaplasia, splitting, crevicing and fibrillation, or core necrosis or fibroplasia were seen only in Group D. Core lesions in Group D often extended proximal to E1, and ranged in length from 0.5-13 cm. Core necrosis was generally associated with increased signal intensity in fat suppressed images. CONCLUSIONS: Lesions of the DDFT in the digit appear to be primarily degenerative, and may be a sequel to vascular compromise. Increased signal intensity on fat suppressed MR images is not necessarily associated with frank fluid or evidence of inflammation, but may reflect major matrix changes in the tendon. POTENTIAL RELEVANCE: Further information about the causes of these lesions is required to develop preventative strategies.

Dorsal suspension stitch: an alternative stabilization after flexor tenotomy for flexible hammer digit syndrome.

The focus of this communication is to share an alternative form of positional maintenance for use after correction of flexible hammer digits via flexor tenotomy. The toe is maintained in a corrected position by means of a wide, horizontal mattress stitch with the suture passing through the extensor apparatus both proximal and distal to the interphalangeal joints. This suture prevents recurrence of plantarflexion contracture of the toe during the postoperative period without the use of Kirschner wire fixation. We have noted satisfactory maintenance and healing with this technique.

Psoriatic Nail Dystrophy Is Associated with Erosive Disease in the Distal Interphalangeal Joints in Psoriatic Arthritis: A Retrospective Cohort Study.

OBJECTIVE: To assess whether the association between psoriatic nail dystrophy and radiographic damage in the hands of patients with psoriatic arthritis (PsA) is specific to the distal interphalangeal (DIP) joints. METHODS: A convenience sample of patients was collated from the Bath longitudinal PsA cohort. All patients had PsA according to the ClASsification for Psoriatic ARthritis criteria (CASPAR) criteria, scored radiographs of their hands, and documented nail scores as measured by the Psoriatic Nail Severity Score. Chi-square tests were performed to examine for association between features of nail dystrophy and radiographic damage in the DIP joints, and proximal interphalangeal or metacarpophalangeal (non-DIP) joints of the corresponding digits. RESULTS: There were 134 patients included, with a median age of 53 years (interquartile range; IQR 44-61) and disease duration of 7 years (IQR 3-17). The presence of any form of psoriatic nail dystrophy was associated with erosion at the DIP joints of the corresponding digit (OR 1.9, 95% CI 1.23-2.83; p < 0.004) and this association was primarily driven by the presence of nail onycholysis (OR 1.72; 95% CI 1.12-2.62; p = 0.02). Nail subungual hyperkeratosis was more strongly associated with joint space narrowing, erosions, and osteoproliferation at the corresponding DIP joint compared to non-DIP joints (p < 0.001). Nail pitting was not associated with erosions or osteoproliferation. CONCLUSION: The presence of psoriatic nail dystrophy, particularly onycholysis, is associated with erosive disease at the DIP joints. Subungual hyperkeratosis is more strongly associated with erosive damage at the DIP than non-DIP joints. These findings support the anatomical and pathological link between nail and DIP joint disease.

MRI changes in psoriatic dactylitis--extent of pathology, relationship to tenderness and correlation with clinical indices.

OBJECTIVES: To quantify the extent of inflammation in psoriatic dactylitis and to examine the relationship between clinical and magnetic resonance imaging (MRI) data in both tender and non-tender dactylitis. METHODS: Seventeen patients with psoriatic dactylitis underwent clinical assessment for 6 months after change of treatment, usually to methotrexate. Measures of dactylitis included the Leeds Dactylitis Index, the assessment tool used in the Infliximab in Psoriatic Arthritis Clinical Trial (IMPACT), a simple count of tender dactlylitic digits and a count of all dactylitic digits, both tender and non-tender. MRI scans of the affected hand or foot were performed before and after treatment using a 1.5T Siemen's scanner pre- and post-contrast. RESULTS: All patients improved clinically, as did their respective dactylitis scores and MRI images. The findings on MRI in both dactylitic and non-dactylitic digits were profound and widespread. The difference between tender and non-tender dactylitis was quantitative rather than qualitative. Synovitis and soft-tissue oedema were the most frequent abnormalities being present in 69% of tender dactylitic digits but bone oedema and flexor tenosynovitis were also frequently seen. Soft-tissue oedema was circumferential and enhancing and not limited to association with the flexor or extensor tendons. None of the clinical indices of dactylitis showed a close relationship to the extent of MRI abnormalities. CONCLUSIONS: MRI images demonstrate widespread abnormalities in digits of people with psoriatic arthritis. Tender dactylitic digits have more abnormalities than other digits but the relationship between clinical and MRI scores is not strong.

The collateral ligaments of the distal interphalangeal joint: magnetic resonance imaging and post mortem observations in 25 lame and 12 control horses.

REASONS FOR PERFORMING STUDY: Magnetic resonance imaging (MRI) is used with increasing frequency to diagnose injuries of the collateral ligaments (CLs) of the distal interphalangeal (DIP) joint, but the results have not been verified by histology and the mechanism of injury is poorly understood. HYPOTHESIS: Abnormal signal intensity and tissue contour represents change in tissue structure detected on histology. OBJECTIVES: To compare results in horses free from and those with chronic lameness and to describe possible progression of lesions. METHODS: One or both feet of horses free from lameness (Group N: n = 12) and with foot-related lameness (Group L: n = 25) were examined using MRI and by gross post mortem examination. The magnetic resonance (MR) images were graded. Sagittal sections from the proximal and distal aspect of each CL were examined histologically and each ligament assigned a score. Scintigraphic images from lame horses were also evaluated. RESULTS: In Group N, 25 CLs were graded normal on both MR images and histology, 2 CLs were grade 1 on MR images, but were histologically normal, and 2 CLs had MR abnormalities verified histologically. However, 2 CLs appeared normal on MR images but were histologically abnormal. In Group L, 18 CLs were deemed normal on both MR images and histology, and 54 CLs had MR abnormalities verified histologically. However, 13 CLs appeared normal on MR images but were graded abnormal histologically. Lesions appeared to be degenerative, characterised by extensive fibrocartilaginous metaplasia and development of multiple, intercommunicating fissures within the degenerate collagen in severe lesions. There was an association between increased radiopharmaceutical uptake and a higher histological score. CONCLUSIONS: High-field MRI is reasonably reliable for detection of lesions of the CLs of the DIP joint, but may underestimate their prevalence. CLINICAL RELEVANCE: Collateral ligament injury appears to be a primary degenerative process, which may explain the poor response to conservative treatment and a need for promotion of regeneration.

Osteochondral fragmentation in the synovial pad of the fetlock in Warmblood horses.

OBJECTIVES: To determine clinical and arthroscopic characteristics associated with fragments in the synovial pad of the fetlock and to characterize their morphology. STUDY DESIGN: Retrospective study. ANIMALS: Warmblood horses (n=104) with fragment(s) in the synovial pad. METHODS: Signalment and results of radiographic and clinical examination were collected before surgery. After arthroscopic fragment removal and joint evaluation for synovial and/or cartilage abnormalities, fragments were measured, and evaluated by histopathology. RESULTS: Synovial pad fragments (n=142) were removed from 127 fetlocks. Two older horses had lameness. During arthroscopy, abnormalities were observed in 40 joints (31.5%) and multivariate logistic regression analysis showed a significant correlation between the observed arthroscopic abnormalities and the presence of large fragments (P=.016). Fragments were osteochondral bodies completely surrounded by fibrous tissue. At the edges of the hyaline cartilage cap an underlying fibrous structure was obvious in the extracellular matrix giving it a reactive pattern. CONCLUSIONS: Although the impact on lameness was minimal, there was a significant correlation between arthroscopic abnormalities and presence of large synovial pad fragments. On histopathology, these osteochondral fragments are embedded in fibrous tissue and show a reactive pattern. They are not a manifestation of any well-described joint pathology. CLINICAL RELEVANCE: Large synovial pad fragments in Warmblood horses can be associated with synovial and cartilage abnormalities, but further studies are warranted to determine their origin and clinical importance.

Enthesitis and Dactylitis in Psoriatic Disease: A Guide for Dermatologists.

Psoriatic arthritis (PsA) is an inflammatory arthritis that is estimated to affect approximately 30% of patients with psoriasis. Enthesitis and dactylitis, two hallmarks of PsA, are associated with radiographic peripheral/axial joint damage and severe disease. Clinical symptoms of enthesitis include tenderness, soreness, and pain at entheses on palpation, whereas dactylitis is recognized by swelling of an entire digit that is different from adjacent digits. Both ultrasound and magnetic resonance imaging can be used to diagnose enthesitis and dactylitis, especially in patients in whom symptoms may be difficult to discern. Delayed treatment of PsA can result in irreversible joint damage and reduced quality of life. Thus, it is recommended that dermatologists monitor patients with psoriasis for these two early and important manifestations of PsA.