The tendon of the thigh muscle is attached at the top of the legbone (tibia) at the tibial tubercle. This is the bump which is normally felt. In growing children the tissue at the attachment is not bone but growing cartilage. A process of repair and breakdown is constantly occurring at this site like all other areas. When the pace of process of breakdown exceeds that of repair, due to the forces exerted by the tendon, then there is a separation of the cartilage. This is manifested by pain and swelling.
.Pain just below the knee joint. which is worse while climbing stairs, jumping or running. It is better at rest. .Swelling over the tibial tubercle. This is the attachment of the thigh muscle tendon. .The pain increases with activity.
.Sudden growth spurt .Obesity .Excessive jumping, running, jogging. .Males between the ages of 11-13 are more prone to get it.
Your orthopaedic surgeon can diagnose this after a clinical examination. An x-ray is confirmative.The orthopaedic surgeon has to differentiate this from other cases of anterior knee pain like patellar tendonitis,fat syndrome etc.
.Reassurance that the condition will settle soon. Immediate measures include ice, compression and a tubigrip support. Mild pain killers like paracetamol will help. .Restriction of sporting and physical activity is important until the condition settles down. .Gentle stretching exercises before sport will help. In resistant cases the orthopaedic expert in sports medicine and knee surgery will reticently remove the loose pieces of bone by opening the patellar tendon.