This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infection of Bones & Joints, Subject name: Orthopaedics
Chronic discharging sinus with bone particle is seen in- 
Select and explain. 
A. Chronic osteomyelitis, B. Acute osteomyelitis, C. Subacute osteomyelitis, D. Garre's osteomyelitis
A: Chronic osteomyelitis
Answer: A: Chronic osteomyelitis 
Explanation: Ans. is 'a' i.e., Chronic osteomyelitis Clinical features of chronic osteomyelitiso The commonest presenting symptom is a chronic discharging sinus, a history of bone piece discharge from the chronic sinus is considered diagnostic of chronic osteomyelitis.o Pain is minimal or absent.o Generalized symptoms of acute osteomyelitis are not present except in acute excacerbations.o On examination there is irregular thickening of bone. Mild tenderness may be seen in deep palpation. Adjacent joint may be stiff.Radiological featureso Following are radiological features : -Thickening and irregularity of the cortices.Patchy sclerosisBone cavity : This is seen as an area of rarefaction surrounded by sclerosis.Sequestrum(Manipal 97): This appears denser than the surrounding normal bone because the decalcification which occurs in normal bone, does not occur in dead bone. Granulation tissue surrounding the sequestrum gives rise to a radiolucent zone around it. A sequestrum may be visible in soft tissue.Involucrum and cloacae may be visible.