1. Chronic osteomyelitis When the duration of osteomyelitis is more than 3 weeks, its called ch. Osteomyelitis. Causes- 1.Trauma causing open fractures. 2.Post operative. 3.Osteomyelitis with chronic etiology- -TB -Brodie’s abscess. -Fungal osteomyelitis.

2. Pathology. 1.Necrosis.  stage of new bone formation  involucrum.  with sequestrum inside, there will always be a persistent discharging sinus.  pus from bone escapes through multiple hole in involucrum

3. Clinical features- -Pain, swelling. -Discharging sinus. -Bone thickening. -Deformity. -Joint stiffness. -Shortening of limb, -Pathological fracture. -Sinus track malignancy.. Discharging sinus

4. Investigation. CBC, ESR. Pus for c/s. X – ray – sequestrum deformity. - periosteal thickening, sclerotic lesion. - irregular soft tissue shadow. - regional osteoporosis. - pathological fracture, micro fracture. CT. MRI

5. D/D- 1.TB osteomyelitis- watery discharge. - previous h/o TB, sinus with undermined margin with blue colour. 2. Ewing's sarcoma- A primary malignant tumor of bone, usually arising as a central tumor in long bone. (biopsy) 3. Soft tissue chronic infection. (X-ray)

6. Treatment. Supportive treatment. Antibiotics – to prevent spread. Surgery – sequestretomy + saucerization (excavation of the tissue of a wound to form a shallo )

7. Complication. Joint stiffness. Shortening. Muscle contracture. Pathological fracture. Sinus track malignancy. Amyloidosis.

8. Brodie’s abscess - it is an intraosseous abscess walled by reactive bone Cause- staph.aureus. Common site- metaphysis of long bone, cancellous bone. Clinical features- pain, fever, swelling, thickening of bone,

9. X- ray radiolucent area in sub periosteum surrounded by sclerotic bone. Treatment- Fenestration + antibiotics (two days of intravenous antibiotics and then oral antibiotics for six weeks )

10. Septic arthritis Collection of pus inside the joint. Common in knee and hip. Cause- staph. Aureus, strept. pyogens, E. coli, pseudomonas, haemophilous influenza,

11. Mode of infection- 1.Haematogenous. 2.Direct penetrating wound to joint, 3.Joint aspirations, steroid injection, contrast injection, arthroscopy. 4.Spreading infection from near by bone.

12. Mode of infection Microbes  synovial membrane  inflammation (synovitis).  increased synovium formation  seorus/ seropurulent discharge  erosion of cartilage  - spreading of pus to the bone and destruction of bone. - escaping of pus outside the joint through sinus.

13. Clinical features Neonates- increased pulse rate, fever, irritable, ignore feeding, swelling of joint, resist the movement of affected joint, pain. Children- swelling, increased pulse rate, fever, restriction of movement of joint. Adult- usually in immunocompromised or with other existing diseases.

14. Investigation. CBC, ESR. Pus for c/s, gram staining. Blood for c/s X-ray – initially normal. - initially increased joint space. - later joint space decreases. - osteopenia. USG- collection of pus inside the joint space.

15. D/D Acute osteomyelitis. Haemarthaesis.- post traumatic. - aspiration. Acute rheumatism. Haemophilic joint Gout.

16. Treatment Supportive measures- 2 wks of IV antibiotics followed by 4-6 wks of oral antibiotics. Symptomatic.(pain, fever) Splintage of affected limb. Surgery – arthotomy and evacuation of pus.

17. Complications. Dislocaton of joint. Deformity around joint. Bony ankylosis.