Nontuberculous mycobacteriosis oligoarthritis of the right hand misdiagnosed as rheumatoid arthritis: A case report.

Infection with Mycobacterium marinum has several different clinical presentations. Most commonly, it appears as a solitary papulonodular lesion on an extremity. A rare presentation of osteoarticular M. marinum involving multiple small joints and tenosynovitis of the hand, which was misdiagnosed as rheumatoid arthritis, is reported. The patient was initially treated for seronegative rheumatoid arthritis but failed to respond to methotrexate. Magnetic resonance imaging showed arthritis and tenosynovitis. Subsequently, synovial biopsy led to histological and microbiological diagnosis. Antimycobacterial treatment should be started promptly in such cases. The combined use of rifampicin, ethambutol, and clarithromycin appears to be effective, and debridement is indicated in patients with deep-seated infections.

Lumbrical muscle enhancement on MRI and its association with rheumatoid arthritis.

OBJECTIVE: To investigate the significance of lumbrical muscle enhancement (LME) on magnetic resonance imaging (MRI) in rheumatoid arthritis (RA). MATERIALS AND METHODS: Blinded to the diagnoses, contrast-enhanced bilateral hand MRIs of patients with suspected early RA between 2014 and 2019 were reviewed by two observers for the presence and degree (weak/strong) of LME. The presence of other inflammatory findings was also noted. The patients were then stratified into RA (n = 41), control (n = 31), and other arthritides groups(n = 28) based on their final diagnoses in the hospital records within the following 12 months. Categorical variables were compared by chi-square test or Fisher's exact test. Differences among the groups were evaluated by one-way ANOVA or Kruskal-Wallis tests. When the p-value from the Kruskal-Wallis test was statistically significant, multiple comparison test was used to identify group differences. Correlations between LME and flexor tenosynovitis were evaluated by Spearman rank correlation test. The agreement between two observers was assessed by Cohen's Kappa (κ) statistic. P-value < 0.05 was considered as statistically significant. RESULTS: There were 100 patients (88 females) with mean age of 47.2 ± 11.2. There were no significant differences for age or sex between groups (p = 0.17, p = 0.84, respectively). RA patients showed significantly more frequent (p < 0.001) and stronger LME (p = 0.001). There were no correlations between LME and flexor tenosynovitis (p > 0.05). Interrater agreement for the degree of LME on right and left sides was substantial (κ = 0.74, κ = 0.67, respectively). CONCLUSION: RA patients demonstrated significantly more frequent and stronger LME with substantial interrater agreement. LME could constitute a subtle radiological clue for early RA.

Proliferative tenosynovitis in Brazilian Mangalarga Marchador horses.

Proliferative tenosynovitis (PT) is an inflammatory and proliferative disorder of the synovial membrane of the tendon sheath that is rare in animals. The histological alterations are characterized by multinodular neovascularization, with infiltration of histiocytic and multinucleated giant cells and haemosiderin deposition. We reviewed necropsy and biopsy records of horses submitted to the Setor de Anatomia Patológica of the Universidade Federal Rural do Rio de Janeiro from January 2017 to December 2020 to select cases of PT. We identified PT in three adult Brazilian Mangalarga Marchador horses with nodular lesions on the metacarpophalangeal, metatarsophalangeal or carpal joints. The three horses were under 6 years of age and presented with lameness and pain on palpation. There were recurrences in two horses after surgical removal. Radiographic and ultrasound examinations detected masses in the flexor or extensor tendons and subtendinous bursa. Histological study of synovial membrane and tendon sheath revealed an increased number of vessels, fibroplasia, osseous metaplasia and infiltration of lymphocytes, plasma cells and siderophages. This is the first description of PT in horses, which should be included as an orthopaedic differential diagnosis, especially in Mangalarga Marchador horses with lameness.

Morphologic, dynamic and high-resolution microscopy MRI in early-onset spondyloarthritis finger dactylitis.

OBJECTIVE: Up to now, the pathophysiology of SpA dactylitis has not been entirely clarified. It is not clear which are the involved tissues and which is the primary lesion of the "sausage-like" digit. The aim of our study was to examine the finger structures in early-onset finger dactylitis using high-resolution microscopy MRI together with morphologic and dynamic MRI. SUBJECTS AND METHODS: In a 6-month period, 13 SpA patients (7 females and 6 males), mean age 54.07 years (range 37-73 years) and mean disease duration 7.07 years (range 1-44 years) with early-onset finger dactylitis (less than 3 months) were recruited. Nine patients had PsA, 3 HLA-B27-positive uSpA and 1 HLA-B27-negative uSpA. One patient had 2 dactylitis fingers. Ten healthy volunteers matched for age and sex with no personal and family history of SpA were enrolled. All dactylitis fingers and randomly selected fingers of the normal control subjects were imaged by morphologic, dynamic and high-resolution microscopy MRI. RESULTS: We have found flexor tenosynovitis in all the 14 dactylitis fingers, joint synovitis in 5 and oedema in the finger soft tissue in 10. In 2 dactylitis fingers, there was oedema at the insertion of the joint capsule suggesting enthesitis. In 5 dactylitis fingers, there was only mild enhancement at the enthesis organ (collateral ligament, flexor and extensor tendons). CONCLUSIONS: Our MRI study on early-onset dactylitis demonstrates that flexor tenosynovitis, joint synovitis and oedema of the digit soft tissue are the predominant alterations visible in the early phase of evolution of dactylitis and that, therefore, enthesitis may not be considered the primary lesion of dactylitis.

Evidence for the presence of synovial sheaths surrounding the extensor tendons at the metacarpophalangeal joints: a microscopy study.

MRI-detected inflammation around the extensor tendons of metacarpophalangeal (MCP-) joints is prevalent in RA and poses a markedly increased risk of RA development when present in arthralgia patients. Such inflammation is called 'peritendinitis' since anatomy literature reports no presence of a tenosynovial sheath at these tendons. However, the presence or absence of tenosynovium at these extensor tendons has never been studied. Therefore, an anatomical and histological study of extensor tendons at the MCP-joints of three embalmed human hands was performed. Immunohistochemical staining showed the presence of markers for synovial macrophages and fibroblast-like synoviocytes bordering a natural dorsal space next to the extensor tendon, suggesting the presence of a synovial lining. This implies that contrast-enhancement on MRI around extensor tendons at MCP-joints observed in early RA and pre-RA likely represents tenosynovitis and that inflammation of this synovial tissue is an early feature of RA.

Localized tenosynovial giant cell tumor: a rare case of snapping hip.

We report on a 40-year-old male with a 9-month-long history of snapping of his right hip caused by a previously undescribed etiology of internal extra-articular snapping hip, namely due to a localized tenosynovial giant cell tumor. Both dynamic ultrasound evaluation and MRI proved to be crucial in the diagnosis of this rare entity. Auto-provocation of the snapping showed an anterior hip mass moving posteriorly to the psoas tendon which elucidated the pain and clicking sensation. Subsequent MRI demonstrated a peripheral low-intensity rim due to hemosiderin deposition around the synovial mass which is indicative for pigmented villonodular tenosynovitis. Treatment consisted of arthroscopic shaver burr resection. Immediately postoperatively, the snapping sensation could not be provoked anymore by the patient. The purpose of reporting on this case report is to emphasize several successive learning points. First, dynamic ultrasound aids in diagnosis and differentiation of the types of snapping hip. Second, specific MRI features are suggestive of tenosynovial giant cell tumor, recognizing these traits may prevent delayed diagnosis and subsequent aggravated clinical course. Third, localized pigmented villonodular tenosynovitis around the hip may present as an internal extra-articular snapping hip and is of consideration in the differential diagnosis of recurrent snapping hip.

Implementation of the OMERACT Psoriatic Arthritis Magnetic Resonance Imaging Scoring System in a randomized phase IIb study of abatacept in psoriatic arthritis.

OBJECTIVES: To investigate if the OMERACT PsA MRI Scoring System (PsAMRIS), including a novel total inflammation score, shows sensitivity to change with an agent (abatacept) known to impact clinical outcomes in PsA. METHODS: We performed a post hoc analysis of a randomized phase IIb study of abatacept in patients with PsA and inadequate DMARD response. Participants received one of three abatacept dosing regimens [ABA3, ABA10 or ABA30/10 mg/kg (30 mg/kg switched to 10 mg/kg after two doses)] or placebo until day 169, then ABA10 through day 365. MRIs at baseline and days 85, 169 and 365 were centrally evaluated by two readers blinded to chronological order and treatment arm. Synovitis, osteitis, tenosynovitis, periarticular inflammation, bone erosions, joint space narrowing and bone proliferation were assessed using the PsAMRIS. A novel total inflammation score was tested. RESULTS: MRIs for 123 patients were included. On day 169, ABA10 and ABA30/10 significantly reduced MRI synovitis and tenosynovitis, respectively, vs placebo [differences -0.966 (P = 0.039) and -1.652 (P = 0.014), respectively]. Synovitis in the placebo group increased non-significantly from baseline to day 169, total inflammation and tenosynovitis decreased non-significantly and all measures improved significantly after a switch to ABA10 [-1.019, -0.940, -2.275 (P < 0.05), respectively, day 365 vs day 169]. Structural outcomes changed minimally across groups. CONCLUSION: Adults with PsA receiving ABA10 and ABA30/10 demonstrated significant resolution of inflammatory components of disease, confirmed by MRI, with synovitis and tenosynovitis improvements consistent with previously reported clinical responses for these doses. Results indicate that a reduction in OMERACT PsAMRIS inflammation scores may provide proof of tissue-level efficacy in PsA clinical trials. REGISTRATION: ClinicalTrials.gov (https://clinicaltrials.gov), NCT00534313.

Association between joint effusions and concomitant structural injuries (tendinitis and structural injury) on MRI in ankle trauma without fracture.

BACKGROUND: The evaluation of correlations among joint effusion, ligament injuries, tenosynovitis and osteochondral lesion of talus (OLT) in the ankle joint is important for developing a treatment plan and predicting prognosis. PURPOSE: To evaluate correlations among tibiotalar (anterior) and talocalcaneal (posterior) joint effusion, tenosynovitis of major flexor tendons, ligaments, and OLT in a group of patients with ankle trauma. MATERIAL AND METHODS: This retrospective study included 101 patients with ankle trauma who underwent magnetic resonance imaging. Two radiologists assessed the presence and amount of effusion in the tibiotalar and talocalcaneal joints from grade 0 to 2, according to the amount of capsular distension. Concomitant structural injuries were assessed in the tibialis posterior (TP), flexor digitorum longus, flexor hallucis longus, and peroneus tendons, and the anterior talofibular ligament, calcaneofibular ligament, anteroinferior tibiofibular ligament, posteroinferior tibiofibular ligament, and OLT. RESULTS: The proportion of anterior and posterior joint effusion according to grade was 67.3% for anterior joint effusion grade 0, 22.8% for grade 1, and 9.9% for grade 2; for posterior joint effusion, grade 0 was 74.2%, grade 1 was 22.8%, and grade 2 was 3.0%. We found statistically significant correlations between posterior joint effusion and tenosynovitis of TP (P < 0.05) and between posterior joint effusion and OLT (P < 0.05). CONCLUSION: Posterior joint effusion is correlated with TP injury and OLT; however, tendon injuries have no correlation with other structural injuries of the ankle joint in a general population with ankle trauma.

Síndrome de la intersección distal. Una causa poco frecuente de dolor en el antebrazo / Distal intersection syndrome: an unusual cause of forearm pain

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Rice bodies in the ankle-a case of isolated tubercular tenosynovitis.

Countries with tuberculosis as an endemic disease face many challenges. Isolated tubercular tenosynovitis is a rare presentation of extrapulmonary tuberculosis and involvement of the ankle is even rare. We present a case of isolated tubercular tenosynovitis of the ankle, the diagnosis of which was suggested radiologically and confirmed by histopathology. Clinicians dealing with tuberculosis infected patients need to be aware of such rare presentations for proper diagnosis and management.

Characterizing hand and wrist ultrasound pattern in primary Sjögren's syndrome: a case-control study.

INTRODUCTION/OBJECTIVES: To evaluate the clinical relevance of high-resolution hand and wrist ultrasound (US) findings and their possible associations with anti-citrullinated peptide antibodies in primary Sjögren's syndrome (pSS). METHODS: Ninety-seven consecutive pSS patients (American-European Consensus Group, 2002) without meeting the American College of Rheumatology (ACR) criteria (1987) for rheumatoid arthritis (RA); 20 RA patients (ACR/European League Against Rheumatism (EULAR) criteria, 2010); and 80 healthy individuals with comparable age, gender, and ethnicity were enrolled in a case-control study. Disease activity was assessed by EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI). US was performed by one expert blinded to anti-CCP, anti-MCV, and IgM rheumatoid factor tested by ELISA. RESULTS: Frequencies of grade 3 synovitis (9.3 vs. 0%, p = 0.004), tenosynovitis (36.1 vs. 3.8%, p < 0.001), and erosions (27.8 vs. 7.5%, p = 0.001) on US were higher in pSS patients than in healthy controls. ESSDAI presented a moderate correlation with the synovitis number (p = 0.001) and tenosynovitis (p < 0.001). Most pSS patients with erosions on US (81.5%) had negative anti-CCP. Nevertheless, anti-CCP ≥ 3× cut-off value was associated with the presence of erosions in pSS (p = 0.026). Erosions in pSS were mainly small size contrasting with moderate/large size in RA (p < 0.001), and positive power Doppler synovitis predominated in RA (p < 0.001). CONCLUSIONS: US identified significant frequencies of grade 3 synovitis, tenosynovitis, and erosions in pSS. Synovitis and tenosynovitis numbers were correlated with ESSDAI. Association between erosions on US and anti-CCP (high titers) in pSS possibly identifies a subgroup with severe arthritis. These findings suggest that US is a useful method for assessing joint involvement in pSS.Key Points• US identified significant frequencies of grade 3 synovitis, tenosynovitis, and erosions in pSS patients in comparison with age- and race-healthy individuals.• Numbers of synovitis and tenosynovitis on US were correlated with ESSDAI values.• Most pSS patients with erosions on US were negative for anti-CCP, but anti-CCP ≥ 3× cut-off value was associated with the presence of erosions in this disease.• Erosions in pSS were mainly small size contrasting with moderate/large size in RA, and positive power Doppler synovitis predominated in RA.

Differences in musculoskeletal ultrasound findings between RS3PE syndrome and elderly-onset rheumatoid arthritis.

OBJECTIVE: To retrospectively analyze the differences in musculoskeletal ultrasound (MSUS) findings to distinguish patients with remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome and patients with elderly-onset rheumatoid arthritis (EORA). METHODS: We consecutively recruited patients with RS3PE syndrome (n = 7) and EORA (n = 22) who underwent pre-treatment MSUS of both hands. Synovial hypertrophy and vascularity of articular synovitis and those of tenosynovitis of the digital flexor tendons and the carpal extensor tendon were evaluated by gray-scale and power Doppler, respectively on a semi-quantitative scale (0-3). The presence/absence of intra-articular synovial effusion, bone erosion, peritendinitis of the digital extensor tendon, and subcutaneous edema were noted. RESULTS: Compared to the EORA group, mild articular synovitis was observed more extensively, and the frequency of intra-articular synovial effusion was significantly higher in the RS3PE syndrome group. Severe articular synovial hypertrophy was more frequent in the EORA group compared to the RS3PE syndrome group, and bone erosion was observed in some EORA cases. Tenosynovitis of the digital flexor tendon was more frequent and severe in the RS3PE syndrome group compared to the EORA group. Although the frequency and severity of tenosynovitis of the carpal extensor tendon were similar in the two groups, digital extensor tendon peritendinitis was more frequent in the RS3PE syndrome group. CONCLUSION: To distinguish patients with RS3PE syndrome from those with EORA, it is important to evaluate not only intra-articular lesions but also extra-articular lesions by MSUS.

Serial magnetic resonance imaging and ultrasound examinations demonstrate differential inflammatory lesion patterns in soft tissue and bone upon patient-reported flares in rheumatoid arthritis.

BACKGROUND: Magnetic resonance imaging (MRI) and ultrasonography (US) are more sensitive than clinical evaluation in assessing inflammation in rheumatoid arthritis (RA). Data is scarce regarding potential link between patient-reported flares and inflammation on imaging. The aim of the study was to explore the pattern and longitudinal associations of inflammatory lesions detected by serial MRI and US in relation to patient-reported flares in patients with RA. METHODS: Eighty RA patients with baseline DAS28CRP < 3.2 and no swollen joints were examined at baseline and followed for 1 year. Patients were requested to contact the hospital in case of patient-reported hand flare accompanied by ≥ 1 tender and swollen joint. The 29 patients who reported hand flare had four extra visits within 4 months from flare onset comprising clinical examination, patient-reported outcomes, MRI, and US of wrists and hands. MRI synovitis/tenosynovitis/bone marrow edema (BME) and US synovitis/tenosynovitis were scored. MRI and US scores at and after the flare were compared to baseline before the flare, and associations were explored by linear mixed models for repeated measurements. RESULTS: Synovitis and tenosynovitis by MRI/US increased significantly at flare onset. Synovitis waned quickly, as did US tenosynovitis. BME showed delayed increase yet persisted, once the patient-reported flare had resolved, as did MRI tenosynovitis. In univariate models, patient-reported flares were associated with all MRI and US inflammatory markers, except for BME, which was only associated with SJC28 and long-lasting flares > 14 days. Independent associations were observed between patient-reported flares and tenosynovitis by MRI and US (p < 0.05). CONCLUSIONS: Patient-reported flares were linked to inflammation detected by serial MRI and US. Differential patterns of inflammatory lesion evolution were observed by serial imaging with early synovial and tenosynovial inflammation, followed by delayed-onset BME.

Mycobacterium arupense finger osteomyelitis: Case report.

We describe a case of persistent tenosynovitis in the right fourth finger of a 50-year-old man that after almost a year of workup was found to be related to osteomyelitis caused by Mycobacterium arupense. The few cases found in the literature were associated with traumatic injuries, environmental contamination, and months of misdiagnosis. Treatment is challenging as there are limited data available on antimicrobial susceptibility and potential side effects of current therapy options.

Ultrasonographic and computed tomographic features of rice bodies in an Arabian horse with atlantal bursitis.

A 19-year-old castrated Arabian male horse presented for evaluation of a firm mass at the dorsal cervical region. Ultrasonography and computed tomography revealed multiple well defined fusiform structures within the atlantal bursa. Multiple glossy smooth, white to yellowish, flattened fusiform structures were removed surgically. These structures were composed of dense fibrin with some leukocytes and red blood cells. The imaging and histopathological features of these structures were similar to chronic 'rice bodies' reported in humans with bursitis or tenosynovitis. This is the first veterinary report describing the imaging features of 'rice bodies' in a horse with atlantal bursitis.

Molecular detection of Mycoplasma synoviae and avian reovirus infection in arthritis and tenosynovitis lesions of broiler and breeder chickens in Santa Catarina State, Brazil.

Infectious arthritis or tenosynovitis in broiler and breeder chickens results in major loss of productivity because of reduced growth and downgrading at processing plants. The most common causative agents of avian infectious arthritis are the bacterium Mycoplasma synoviae and avian reoviruses (ARVs) (family Reoviridae, genus Orthoreovirus). In this study, we evaluated the occurrence of these two pathogens in arthritis or tenosynovitis lesions of broilers and breeder flocks in southern Brazil using molecular detection. Tissue sections from tibiotarsal joints with visible lesions from 719 broilers and 505 breeders were analysed using pathogen-specific polymerase chain reaction (PCR) assays. In breeders, 41.2% (n = 296) of lesions were positive for M. synoviae, 26.4% (n = 190) were positive for ARV, while co-infection was present in 12.2% (n = 88) of the samples. In broilers, 20.8% (n = 105) of lesions were positive for M. synoviae, 11.9% (n = 60) for ARV and 7.7% (n = 39) of these cases were positive for both pathogens. Post-mortem examination revealed lesions with varying degrees of gross pathological severity. Histopathological examination showed intense, diffuse lymphohistiocytic inflammatory infiltrates with heterophil accumulation, primarily in the synovial capsule and digital flexor tendon, in all samples. Improved strategies for early detection and control of these major avian pathogens are highly desirable for preventing the spread of infection and reducing economic losses in the poultry industry.

A search to the target tissue in which RA-specific inflammation starts: a detailed MRI study to improve identification of RA-specific features in the phase of clinically suspect arthralgia.

OBJECTIVE: Based on a unique cohort of clinically suspect arthralgia (CSA) patients, we analysed which combinations of MRI features at onset were predictive for rheumatoid arthritis (RA) development. This was done to increase our comprehension of locations of RA onset and improve the predictive accuracy of MRI in CSA. METHODS: In the discovery cohort, 225 CSA patients were followed on clinical arthritis development. Contrast-enhanced 1.5 T MRIs were made of unilateral metacarpophalangeal (MCP) (2-5), wrist, and metatarsophalangeal (1-5) joints at baseline and scored for synovitis, tenosynovitis, and bone marrow edema. Severity, number, and combinations of locations (joint/tendon/bone) with subclinical inflammation were determined, with symptom-free controls of similar age category as reference. Cox regression was used for predictor selection. Predictive values were determined at 1 year follow-up. Results were validated in 209 CSA patients. RESULTS: In both cohorts, 15% developed arthritis < 1 year. The multivariable Cox model selected presence of MCP-extensor peritendinitis (HR 4.38 (2.07-9.25)) and the number of locations with subclinical inflammation (1-2 locations HR 2.54 (1.11-5.82); ≥ 3 locations HR 3.75 (1.49-9.48)) as predictors. Severity and combinations of inflammatory lesions were not selected. Based on these variables, five risk categories were defined: no subclinical inflammation, 1-2 locations, or ≥ 3 locations, with or without MCP-extensor peritendinitis. Positive predictive values (PPVs) ranged 5% (lowest category; NPV 95%) to 67% (highest category). Similar findings were obtained in the validation cohort; PPVs ranged 4% (lowest category; NPV 96%) to 63% (highest category). CONCLUSION: Tenosynovitis, particularly MCP-extensor peritendinitis, is among the first tissues affected by RA. Incorporating this feature and number of locations with subclinical inflammation improved prediction making with PPVs up to 63-67%.

Deep infection with Mycobacterium marinum: successful treatment of a frequently misdiagnosed disease.

We report a rare yet typical presentation of a severe infection with Mycobacterium marinum that affected the deep structure of the hand and wrist of a 43-old fish breeder. A combination therapy of surgical debridement and antibiotic treatment with clarithromycin and ethambutol for 6 months led to a total resolution of the symptoms. Intensive rehabilitation completely restored the function of the hand.