Knee

Knee pain is common at all ages in childhood and adolescence. It may arise from local knee pathology, be referred from the hip, or form part of a systemic or inflammatory condition. Careful assessment is essential, including consideration of red flag causes such as infection and malignancy.

Anterior knee pain

Anterior knee pain is particularly common in adolescents and is often worse with exercise. It may be influenced by foot posture, leg alignment and hypermobility.

Osgood–Schlatter disease is a common cause in physically active adolescents, particularly boys involved in sports such as football or basketball. Symptoms relate to traction at the tibial tuberosity and typically worsen with activity.

Chondromalacia patellae (patellofemoral pain) is more common in adolescent girls and may be associated with hypermobility, flat feet and genu valgum (knock knees). Pain is usually anterior and activity-related.

Traumatic knee injury

Significant trauma to the knee may result in meniscal injury or damage to the cruciate or collateral ligaments. These injuries are usually associated with a clear mechanism of injury and may present with bruising, swelling (including haemarthrosis), locking, instability or giving way. Such presentations require prompt assessment and appropriate referral.

Osteochondritis dissecans

Osteochondritis dissecans can occur in children and adolescents and may result in a loose osteochondral fragment. It typically presents with pain and tenderness over the femoral condyle, most often the medial femoral condyle, and may be associated with swelling or mechanical symptoms.

Referred pain

Knee pain may be referred from pathology in the hip, so hip examination is important, particularly where knee findings are minimal or symptoms are atypical.

Inflammatory and red flag causes

Inflammatory arthritis commonly affects the knee and may present with swelling, stiffness and reduced range of movement. Red flag conditions such as septic arthritis, osteomyelitis and malignancy must always be considered, particularly in children who are acutely unwell, febrile, unable to weight bear, or have persistent night pain or systemic symptoms.