An 8 year old boy presents with a gradually progressing swelling and pain since 6 months over upper tibia. On X-ray, there is a lytic lesion with sclerotic margins in the upper tibial metaphysis. The diagnosis is

.brodie&;s abscess is a type osteomyelitis in which the body&;s defence meechanism have been able to contain the infection so as to create a chronic bone abscess containing pus or jelly like granulation tissue surrounded by a zone of sclerosis. clinical feature- common site are upper tibia and lower end of the femur. it is usually located at the metaphysis,deep boring pain,become worse at night. radiological finding - circular or oval lucent area surrounded by zone of sclerosis (Ref: Essential ohopaedic,maheshwari & mhaskar, 5th edition ,pg no.175)