Proceedings of the 24th Paediatric Rheumatology European Society Congress: Part two

Abstract

Introduction: Juvenile arthritis is a broad term that describes hetero-geneous group of a chronic inflammatory joint disease which characterized by progressive course leading reduced mobility and function. Progressive chronic arthritis of an unknown cause lasting for at least more than three months are the main diagnostic criteria of JIA. A typical classic variant of oligoarticular JIA (oligo-JIA) is well known. Monoarthritis of the elbow joint is atypical onset oligo-JIA. It's diffi-cult to differentiate of elbow chronic synovitis due to clinically het-erogeneous. The instrumental and specific diagnostic tests are great assistance to determine cause of synovitis. Objectives: Chronic synovitis in children arises from several causes. There are inflammatory, infectious, traumatic, reactive, hemorrhagic, neoplastic and undifferent etiologies of synovial diseases. Usually chronic elbow monoarthritis associated with tumor-like conditions (pig-mented villonodular synovitis, synovial haemangioma and chondroma-tosis), osteomyelitis, tuberculosis arthritis, osteochondropathy and rare JIA. The aim of the present study was to determine diagnostic and treatment strategies of elbow monoarthritis manifested like oligo-JIA. Methods: We carried out a retrospective review of sixteen children with chronic undifferentiated elbow monoarthritis which were hospi-talized at Children Orthopedics Institute, Saint-Petersburg (rheuma-tology department) between 2011 and 2016. The data of clinical, serological, X-ray, ultrasound, MRI, arthroscopy and synovial fluid were analyzed. Detected atypical/diffuse form synovial proliferation or limited to a well-defined single nodule were recommended for arthroscopy and biopsy. Six children were excluded from study due to verification of cause elbow monoarthritis: 6-yr-old girl-PVNS, 10-yr-old boy cavernous haemangioma and 17-yr-old boy-synovial chondromatosis, 2 small girls and 1 boy-osteoid osteoma. Ten children were study group (median age 5,8 ± 2,5, range 3-11 years; female 90%, male 10%). Children with post-traumatic elbow joint transient effusion were controls. Results: Trauma of elbow joint related to onset chronic arthritis, progressive flexure contracture with dry synovitis, low activity and the long-term period absence of clinical involvement of other joints were occurred in all children. Asymptomatic early-stage, progressive flexure/combined contracture less joint effusion and morning stiffness were cause of late diagnosis of oligo-JIA. Only seven children (all girls) were ANF positive ≥ 1:160, two HLA-B27 positive. Radiographic finding of early-stage JIA were accelerated cartilage model ossification of distal humeral epiphysis and trochlear, osteoporosis with sub-chondral bone sclerosis and cyst-like deformation. The MR imaging were non-specific inflamed elbow synovium. Overgrowth of epiphy-sis and trochlear with joint space narrowing, deformation articular surfaces with erosive changes were radiographic findings of late-stage JIA. MR imaging revealed significance multiple erosive synovitis with bone cyst-like deformation. Ultrasound wasn't show elbow synovitis at half of the study children. 70% children were negative effect of monotherapy NSAID. Positive treated effect was achieved after intra-articular triamcinolone injection (20-40 mgs) and metho-trexate therapy (15 mg/m2/week) > 6 months, splinting and physio-therapy. After 2-3 years 30% children were persistence oligo-JIA (involved wrist or knee), 40%-extended oligo-JIA, 30%-isolated monoarthritis. Children with post-traumatic elbow joint deformation haven't revealed chronic synovitis. Conclusion: Monoarthritis of elbow joint are rare atypical manifestation of pauciarticular JIA. Non-specific clinical signs and instrumental imaging may contribute to diagnostic problems of elbow chronic synovitis. Therapy of elbow chronic idiopathic monoarthritis must be coincide treat-to-target strategy in juvenile arthritis. Ultrasound can't be the decisive diagnostic method of chronic elbow pathology.