<prompt> Chronic osteomyelitis is diagnosed mainly bySequestrumBone fractureDeformityBrodies abscess  <response>: SEQUESTRUM -- is a piece of dead bone , surrounded by infected granulation tissue trying to eat the sequestrum away. It appears pale having smooth inner surface and a rough outer. When SEQUESTRUM IS COMPLETE, it lies in the free cavity and is LESS attacked by granulation tissue and is absorbed more slowly. Meanwhile , the surrounding living bone attempts to wall off the infection by forming a thick , dense wall , the INVOLUCRUM. INVOLUCRUM is the dense sclerotic bone overlying the sequestrum. An involucrum usually has multiple openings, the cloacae , through which exudate , bone debris , and sequestra find exit and pass through sinus tracts to the surface. CONSTANT DESTRUCTION of neighboring soft tissue leads to THIN skin which is easily traumatised , skin epithelium grows inwards to line the sinus tract. In chronic osteomyelitis of long standing , multiple cavities and sequestra exist throughout the bone The shaft becomes thickened , irregular and deformed. ref : maheswari 9th ed 