Left knee pain and bilateral knee swelling in an adolescent.

Abstract

A 14-year-old boy was referred by the rheumatology department to our orthopaedic service for evaluation of new-onset left knee pain and swelling during the past 2 months. The patient reported no history of injury or trauma and had no prior left knee problems. He had no mechanical symptoms, such as locking, catching, and giving way. He also had not experienced fevers, chills, weight loss, or night pain, but he did notice worsening of his symptoms when he was more active, whereas rest improved his symptoms. He did not have pain at rest. The patient had presented 2 years earlier to his pediatrician with painless right knee swelling. He then underwent an outside orthopaedic and rheumatology evaluation. A review of the medical record from these earlier visits revealed a mild right knee effusion, a stable knee examination, no pain on palpation of his right knee, and a level gait. He was able to jump on each foot and arise from a squat without pain, and he had no swelling or pain symptoms in other joints. Laboratory evaluation at that time revealed an erythrocyte sedimentation rate of 2 mL/ hour, C-reactive protein of 0.11 mg/dL, and negative antinuclear antibody, HLA-B27, and rheumatoid factor tests, and a white blood cell count of 6.4 9 10/mm. An arthrocentesis was performed, which was not suggestive of Lyme disease, crystalline arthropathy, or infection. Gram stain and cultures were negative. Six months later, he was evaluated by rheumatology and his examination was unchanged. His father had a positive history for enthesopathy (plantar fasciitis), but his family history otherwise was negative for reactive arthritis, rheumatoid arthritis, inflammatory bowel disease, psoriasis, ankylosing spondylitis, systemic lupus erythematosus, scleroderma, dermatomyositis, Raynaud disease, and sarcoidosis. The rheumatology service made a diagnosis of oligoarticular juvenile idiopathic arthritis. The patient was treated with cortisone injections; however, they did not provide relief of his swelling. At the time of our evaluation, he still was experiencing painless right knee swelling, although his primary complaint now was left knee pain and swelling. His medical history otherwise included several minor surgical procedures, including a tonsillectomy and adenoidectomy, mole removal, and tooth disimpaction. He had been taking NSAIDs for his left knee pain, but was taking no other medications and reported no drug allergies. On physical examination, he appeared as a well-developed, well-nourished male. He ambulated with a normal, nonantalgic gait. Examination of his left lower extremity showed full, painless hip ROM. His knee ROM was 0 to 140 with some discomfort at terminal flexion and extension. He had a small joint effusion and infrapatellar fat pad Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.