Knee Complaints in Growing Children

Essentials

• Knee problems in children are encountered regularly by primary care physicians.
• It is important to carry out a thorough clinical examination. Referred pain from a back or hip disease should be excluded during the examination. The need for further investigations depends on the degree of clinical signs present.
• Most knee problems in growing children - often vaguely associated with exercise or physical activity - are so mild that they do not cause functional impairment. However, a significant mechanical defect, an overuse injury or arthritis may be suspected if the pain makes the patient limp continuously or limits sports activities, or if the patient describes mechanical locking of the knee or, for example, dislocation of the patella.
• The affected knee should be compared with the contralateral knee. Positive clinical signs include the following: limited range of motion, instability, effusion, synovial swelling, other swelling or deformity, differences in temperature (heat or coolness), atrophy of thigh muscles, local tenderness in sites typical of overuse injuries, asymmetrical tenderness during patellofemoral compression, continuous limping and a side-to-side difference when squatting on one leg.
• It is common for the child and the accompanying adult to assume that the current knee problem is associated with a structural abnormality of the foot or knee. The observations of the accompanying adult should be taken seriously even though a causal relationship between a structural variation and knee pain is extremely rare.

Chondromalacia patellae (patellofemoral pain syndrome)

Osgood-Schlatter disease and Sinding-Larsen disease

Osteochondritis dissecans of the knee

• See Osteochondritis Dissecans (OCD) of the Knee.

Synovial plicae of the knee (plica syndrome)

• Intra-articular folds (plicae) of the synovial membrane are normal structures and are encountered in almost all people, including asymptomatic people. This diagnosis is often reached when persistent, unspecified knee pain warrants arthroscopy. If the only finding during the arthroscopy is a synovial fold it is usually removed in the hope that the patient's symptoms would improve.
• In some cases the symptoms improve, in others not. The clinical relevance of this diagnosis is therefore controversial. It has been assumed that a fold may scar or thicken as a result of trauma or overuse, and these indications have been cited postoperatively when justifying the surgical intervention.
• There must be good grounds to carry out knee arthroscopy in a child since the procedure must be carried out under general anaesthesia, and it is unlikely that an untreated fold would lead to significant permanent damage. If the assumed fold causes clinical signs, e.g. limping, limited range of movement or muscle atrophy, the procedure is warranted after an MRI scan.

Unspecified knee pain in an adolescent

• A very common reason for seeking medical attention, especially in girls at the end of their growing period.
• Symptoms are associated with the growth spurt. The condition is referred to as ”adolescent growing pains” and will improve spontaneously within weeks to months.
• Other diagnoses can with sufficient certainty be excluded in the initial assessment if there are no objective clinical findings and if the native x-ray is normal.
• The pain is nonspecific and the episodes of pain last from a few seconds to several hours. The symptoms are often not related to exercise or are vaguely associated with school sports or other physical activity.