What are the common diagnoses and treatment options for pediatric patients with chronic knee pain?

From the Guidelines

Common diagnoses for pediatric chronic knee pain include Osgood-Schlatter disease, patellofemoral pain syndrome, patellar tendinitis, juvenile idiopathic arthritis, and growth plate injuries, with treatment typically beginning with conservative measures. The most recent and highest quality study, 1, highlights the importance of prompt initiation of appropriate therapy in preventing permanent damage and improving outcomes in juvenile idiopathic arthritis, a common cause of chronic knee pain in pediatric patients.

Key Diagnoses and Treatment Options

• Osgood-Schlatter disease: characterized by pain and swelling below the knee, often treated with rest, ice, compression, and elevation (RICE protocol), and knee straps or patellar stabilizing braces for symptomatic relief.
• Patellofemoral pain syndrome: involves pain around or behind the patella, managed with physical therapy focusing on strengthening quadriceps, hamstrings, and core muscles, and activity modification.
• Patellar tendinitis: inflammation of the patellar tendon, treated with rest, ice, compression, and elevation, and physical therapy to strengthen surrounding muscles.
• Juvenile idiopathic arthritis: a chronic inflammatory disease, treated with disease-modifying antirheumatic drugs (DMARDs) as initial therapy, which is strongly recommended over NSAID monotherapy, according to 1.
• Growth plate injuries: require careful management to prevent long-term damage, often involving rest and physical therapy.

Treatment Approach

Treatment typically begins with conservative measures, including:

• Rest, ice, compression, and elevation (RICE protocol)
• Over-the-counter pain medications such as ibuprofen (10mg/kg every 6-8 hours, maximum 600mg per dose) or acetaminophen (15mg/kg every 4-6 hours, maximum 1000mg per dose)
• Physical therapy focusing on strengthening quadriceps, hamstrings, and core muscles
• Activity modification, with reduced impact activities during acute pain phases

Referral Criteria

Persistent pain lasting more than 2-3 months despite appropriate treatment, pain accompanied by swelling or limited range of motion, or pain that wakes the child at night warrants referral to pediatric orthopedics or rheumatology for further evaluation, as indicated by the guidelines 1.

From the FDA Drug Label

In a 6-month double-blind, placebo-controlled trial of 127 pediatric patients with juvenile rheumatoid arthritis (JRA) (mean age, 10.1 years; age range, 2.5 to 18 years; mean duration of disease, 5. 1 years) on background nonsteroidal anti-inflammatory drugs (NSAIDs) and/or prednisone, methotrexate given weekly at an oral dose of 10 mg/m2 provided significant clinical improvement compared to placebo as measured by either the physician’s global assessment, or by a patient composite (25% reduction in the articular-severity score plus improvement in parent and physician global assessments of disease activity).

The common pediatric chronic knee pain diagnoses include Juvenile Rheumatoid Arthritis (JRA), specifically polyarticular-course JRA.

• Treatment options for pediatric patients with chronic knee pain due to JRA may include methotrexate, given weekly at an oral dose of 10 mg/m2, in combination with nonsteroidal anti-inflammatory drugs (NSAIDs) and/or prednisone 2.
• Methotrexate has been shown to provide significant clinical improvement in pediatric patients with JRA, as measured by the physician’s global assessment or a patient composite score.
• The use of methotrexate in pediatric patients with JRA has been studied, and it is indicated in the management of selected adults with severe, active rheumatoid arthritis, or children with active polyarticular-course juvenile rheumatoid arthritis 2.

From the Research

Common Diagnoses

• Osgood-Schlatter disease: a traction apophysitis of the tibial tubercle, common in children and adolescents, especially those participating in high-impact sports 3, 4
• Patellofemoral pain syndrome: characterized by pain behind or around the patella, often provoked by activities such as climbing stairs, squatting, or running 5, 6
• Patellar tendinitis: inflammation of the patellar tendon, often caused by overuse or repetitive strain 5
• Patellofemoral instability: a condition where the patella does not track properly in the femoral groove, leading to pain and instability 5
• Primary popliteal cysts: fluid-filled cysts in the popliteal fossa, often requiring no treatment unless symptomatic 7
• Plica syndrome: inflammation of the plica, a fold of synovial tissue in the knee joint, often treated with arthroscopic resection if conservative measures fail 7
• Discoid meniscus: a rare condition where the meniscus is thicker and more disc-like, often requiring operative therapy if symptomatic 7

Treatment Options

• Conservative management: rest, icing, activity modification, and rehabilitation exercises, successful in over 90% of patients with Osgood-Schlatter disease 3, 4
• Nonoperative measures: targeted to correct neuromuscular control and kinetic chain dysfunction, effective for most patients with anterior knee pain 5
• Pharmacotherapy: NSAIDs, glucocorticosteroids, and glycosaminoglycan polysulphate may be used to reduce pain symptoms, but evidence is limited and conflicting 6
• Operative therapy: may be necessary for patients with persistent symptoms or severe conditions, such as discoid meniscus or plica syndrome 3, 7, 4
• Physical therapy: quadriceps and hamstring stretching, and exercises to improve neuromuscular control and kinetic chain function, important for prevention and treatment of chronic knee pain 3, 7, 5