Brodie’s abscess is -
Chronic osteomyelitis is of 3 types: 
a) chronic osteomyelitis secondary to acute osteomyelitis 
b) Garre's osteomyelitis 
c) Brodie's abscess 

Brodies abscess is a special type of osteomyelitis in which body's defence mechanism have been able to contain infection so as to create chronic bone abscess containing pus or jelly-like granulation tissue surrounded by a zone of sclerosis. 
C/f: Common in 11-20 years Common sites upper tibia and the lower end of femur A deep boring pain is a predominant symptom. can become worse to-night. Examination reveals tenderness and thickening of bone.
Chronic osteomyelitis
Subacute osteomyelitis
Acute osteomyelitis
Septic arthritis