Knee pain in children
Painful knee or lower legs is becoming common occurrence in children as well as adolescent with increasing level, frequency and variety of sports. A planned approach to painful knee can help with diagnosis and avoid pitfalls.
Knee pain in a child can be due to wide range of causes. It can be due to acute injury, chronic injury, hip pain or systemic causes.
Acute injury can be due to fall, bike riding, football or skiing. In younger children soft tissue injury, minor bruising, sprains, fractures or patella dislocation are common. In older children ligament, meniscal tears and ACL injuries are becoming commoner.
Plain x-rays are essential if a child presents with
- Large effusion
- Tenderness around joint
- Inability to weight bear
In addition, if an adolescent had significant knee injury (football/ rugby injury, felt a pop or snap in the knee with immediate swelling); MRI scan is needed to evaluate ligaments and meniscus.
Chronic pain is pain lasting more than six weeks. It can be due to injury that has not healed or due to overuse injury. It can be due to systemic causes (inflammatory arthritis, infections) or rarely due to malignancy.
Careful history and examination as well as localising pain will help identify cause of chronic pain. If a child has effusion, locking jamming or is unable to weight bear, plain x-rays are required.
Perthes disease of hip or SUFE of hip can present with referred pain around knee. In these cases, hip movements will be painful and restricted on the affected side. X-rays of hips are needed!
Chronic or acute knee pain without inciting trauma or a history of overuse is a “red flag” In such cases a more extensive evaluation is required, particularly if the pain is associated with constitutional symptoms, such as fever, night sweats, chills, malaise, weight loss, or fatigue or if the pain is severe enough to awaken the patient from sleep. These cases need urgent referral to paediatrics (if more than one joint is involved) or to orthopaedics (if only one joint is involved).