Children's Knee Problems

Children’s Knee Injuries, Soft Tissue Knee Problems

Knee pain is common in adolescents with Osgood-Schlatter's, Jumper’s knee / patellar tendinopathy and Patellofemoral dysfunction being particularly common.
The principal potential pitfall when assessing a child with knee pain is failure to take the hip joint into consideration. Hip pathology can present purely with knee pain, particularly in children, and potentially serious hip conditions such as Slipped Upper Femoral Epiphysis can be missed if the hip is not examined. In any child presenting with knee pain, it is therefore mandatory to examine the hip.
Children’s knee injuries may present to Accident & Emergency or one of our Minor Injury Units with onward referral to our on-call service or Virtual Fracture Clinic as required.
Some knee injuries may present later with recurrent instability, pain, swelling or locking. Some knee problems (e.g. osteochondritis dissecans, discoid meniscus) have no history of injury.
Knee pain may also be a feature of an inflammatory arthropathy, underlying infection (e.g. Brodie’s abscess) or tumour.
Where there is a confirmed or suspected structural knee problem (e.g. ligament injury, meniscal problem, patellar instability), referrals can be made to the Adult Orthopaedic Knee Service to be reviewed by one of our soft tissue knee surgeons. Alternatively, referrals made to the Children’s Orthopaedic Service may be redirected to one of our knee surgeons.

Normal children’s knee alignment varies with age and there is considerable normal variation between children. Knee alignment is normally 10-15° varus (bow-legged) at birth, neutral at around 20 months , up to 15° valgus at 3-4years and normal physiologic valgus (5-7°) by age 7.
Unilateral problems are more likely to indicate an underlying abnormality (rather than physiologic variation). Any genu varum after the age of 2 is also considered abnormal.
Underlying causes of pathologic abnormal knee alignment include metabolic bone disease, physeal injury / infection, Blount’s disease (pathologic genu varum), skeletal dysplasia, congenital deformity and benign tumours.
Most cases are mild, bilateral and physiologic. Such cases do not require any treatment. Bracing is not considered effective.
Where there is uncertainty, assessment can be made by the Children’s Physiotherapy Service.
Where there is a clear abnormality, referral can be made to the Children’s Orthopaedic Service.

For cases of unexplained knee pain, a referral should be made to our Children’s Orthopaedic Service. The hips should be examined and ideally x-rays should be performed of the knee +/- hips. Remember the pitfall – Hip pathology (e.g. SUFE, Perthes) can present with knee pain!!
Where there is knee pain as part of a poly-arthropathy or where there is suspicion of an inflammatory arthropathy (e.g. Juvenile Idiopathic Arthritis), referral should be made to Paediatrics.