OSTEOMYELITIS - Infection of bone marrow with subsequent affection of cortex

Osteon means “bone”
•Myelitis means ”bone marrow inflammation”
•Osteomyelitis (OM) refers to primary infection of the bone marrow with subsequent affection of the bone (cortex) and periosteum

1. OSTEOMYELITIS INTRODUCTION PATHOGENESIS DIAGNOSIS TREATMENT Presenter – Dr. Sarvagya Jain (JR 2) Moderator - Dr. Akshay Jain (Assistant Professor) Dr. Siddharth Rathore (Assistant Professor) DEPARTMENT OF ORTHOPAEDICS

2. Osteon means “bone” Myelitis means ”bone marrow inflammation” Osteomyelitis (OM) refers to primary infection of the bone marrow with subsequent affection of the bone (cortex) and periosteum Term coined by NELATON in 1844 TYPES : 1) ACUTE OM 2) CHRONIC OM 3) SUBACUTE OM

3. ETIOLOGY Most common – Staphylococcus aureus Most common in Acute OM , Chronic OM : Staphylococcus aureus Most common in Developing and Developed nation : Staphylococcus aureus Patients with HIV, DM, Immunocompromised status : Staphylococcus aureus Open Fractures and post surgery : Staphylococcus aureus Patient with Sickle cell disease: Salmonella ( occurs in diaphysis) I/V drug abusers : Pseudomonas Animal bite : Pateurella Human bite : Eikenella

4. ACUTE OSTEOMYELITIS Infection present for less than 6 weeks INFLAMMATORY SYMPTOMS AND SIGNS : Fever with or without chills, malaise. Rubor - Redness Dolor - Pain Calor - Rise in local temperature Tumor - Swelling Functio Laeso – Limited range of motion of affected part

5. PATHOGENESIS bacteria lodge adjacent to the physis , in relation to terminal metaphyseal vessels. vessels are “open ended “ ( and NOT looped or “hair pin bends” as visualized by Trueta and Hobo). vessels enter into “open circulation” bacteria adhere to cartilage cells at the junction between physis and metaphysis. The bacteria here divide thriving on dead chondrocytes produce inflammation and tissue death secondary to ischemia from either venous or arterial obstruction. Liquefactive necrosis of medullary tissue. Trabeculae of the cancellous bone lose their vascularity and die remaining in the pus as small sequestrate.

6. DIAGNOSTIC CRITERIA FOR ESTABLISHING THE DIAGNOSIS 2 OF THE FOLLOWING MUST BE PRESENT Pus on aspiration from affected bone Positive Bacterial culture from bone tissue or blood ( 50 % cases) Clinical features of acute osteomyelitis (described previously) Typical Radiographic Changes of OM

7. CRITERIA TO DETERMINE LIKELIHOOD OF HAVING OM DEFINITE : Pathogen isolated from bone or adjacent soft tissue OR there is histologic evidence of OM PROBABLE : A blood culture is positive in the setting of clinical and radiographic features of OM LIKELY : Typical clinical settings and definitive radiographic evidence of OM are present and there is response to antibiotic therapy

8. CHRONIC OSTEOMYELITIS Infection present usually for more than 6 weeks SEQUESTRUM FORMATION : Pathological hallmark Clinical hallmark : SINUS Higher risk for patients with associated morbidity like Diabetes Mellitus, immunosuppression, rheumatoid arthritis; etc.

9. SEQUESTRUM Patholological hallmark for Chronic OM Dead, radioluscent ,ischemic, necrotic, non viable piece of bone Separates from underlying viable healthy parent bone Surrounded by reactive, immature, subperiosteal new bone (INVOLUCRUM) Nidus of infection 2 sufaces : Rough and Smooth Under microscope : No haversian system seen Never bleeds Ideal time for sequestrum to develop : 2-3 months

10. CIERNY AND MADER CLASSIFICATION

11. PATHOGENESIS It develops in one of the following ways : Incomplete treatment of acute OM (most common) Trauma Implant related infection ( 2 nd most common) A hematogenous type of OM Compound fractures Infection with chronic persistent type of microbes MTB, Treponema sp., fungal OM associated with diabetic foot, vascular disease; etc.

12. DIAGNOSTIC CRITERIA Imaging studies demonstrating Sequestrum and contiguous soft tissue infection CLINICAL SIGNS : Discharge of bone pieces from sinus tract Exposed bone Persistent sinus with or without frank pus discharge Necrotic tissue overlying bone Non healing wound exposing surgical hardware Non healing wound overlying fracture

13. LABORATORY EVALUATION Positive Blood cultures Increased CRP level Increased ESR Serum procalcitonin levels : sensitive and specific marker of OM 48 -72 hours > 0.4 ng/ml

14. SUBACUTE OSTEOMYELITIS Comparing to Acute OM, Subacute OM has more insidious onset and lacks severity of symptoms which makes its diagnosis difficult No definitive guidelines exists for diagnosis Subacute OM is thought to be the result of Increased host resistance Decreased bacterial virulence Administration of antibiotics before the onset of symptoms

15. BRODIE ABSCESS Localised form of Subacute OM Long bones of the lower extrimities of young adults. Before physeal closure, metaphysis is most often affected In adults, metaphyseal-epiphyseal area is involved Intermittent pain of long duration Local tenderness over the affected areas On plain radiograph, lytic lesion with a rim of sclerotic bone mistaken for neoplasm MRI is helpful in diagnosis Open biopsy with curettage to make diagnosis

16. SCLEROSING OSTEOMYELITIS OF GARRE Chronic form Bone thickened and distended Abscess and sequestrum are absent Children and young adults Low grade, possibly anaerobic bacteria M/C Bone affected: Mandible D/D : 1) Osteoid osteoma 2) Paget disease

17. PRESENTATION: Pain - moderate intensity long duration Swelling and tenderness XRAYS : Expanded bone with generalized sclerosis ESR raised slightly BIOPSY : chronic, low grade, non specific osteomyelitis CULTURE : negative Treatment : Fenestration of the sclerotic bone and antibiotics

18. TREATMENT OF ACUTE OM Surgery + Antibiotic treatment In some patients, antibiotic treatment alone cures the disease In Others, prolonged antibiotic treatment is doomed to failure without surgical treatment. The choice of antibiotic is based on : Highest bactericidal activity Least toxicity Lowest cost Sequestered abscess - Surgical drainage required Areas without abscess formation can be treated with antibiotics alone

19. In 1983 , NADE proposed 5 principles for treating Acute OM An appropriate antibiotic is effective before abscess formation Antibiotics do not sterilize avascular tissues or abscesses, and such areas require surgical removal If such removal is effective, antibiotics should prevent their reformation, and primary wound closure should be safe Surgery should not damage further already ischemic bone and soft tissue Antibiotic to be continued after surgery

20. General supportive care : I/V fluids, appropriate analgesics comfortable positioning of affected limb Abscess absent on MRI or USG : empirical intravenous antibiotic therapy started monitored with CRP every 2-3 days of starting it No appreciable clinical response to antibiotic in 24-48 hours: occult abscess must be present and surgical drainage required. 2 main indication of surgery in Acute OM are: Presence of abscess requiring drainage Failure of patient to improve despite appropriate intravenous antibiotic treatment

21. Objective of surgery : drain any abscess cavity remove all non viable or necrotic tissue SUBPERIOSTEAL ABSCESS : several small holes drilled through the cortex into the medullary canal. INTRAMEDULLARY PUS : small window of bone is removed The skin is closed loosely over drains and the limb is splinted Limb is protected for several weeks to prevent pathologic fracture I/V antibiotics should be continued post operatively

22. TREATMENT OF CHRONIC OM Multifactorial approach Antibiotic suppression + surgical debridement + reconstruction. In addition to these, correct host morbidities also Surgery : SEQUESTRECTOMY AND RESECTION OF SCARRED AND INFECTIOUS BONE AND SOFT TISSUE. Goal of Surgery : eradication of the infection by achieving a viable and vascular environment. Success of treatment depends on adequacy of debridement.

23. Antibiotic Polymethyl methacrylate (PMMA) beads typically are used to fill the dead space created by initial debridement. Reaming the intramedullary canal after debridement and lavage and inserting gentamicin impregnated rod and beads

24. STEPS SINOGRAM SINUS TRACT EXPLORATION SEQUESTERECTOMY SAUCERISATION CURETTAGE BONE GRAFTING/ BONE CEMENTING DEBRIDEMENT SINUS TRACT EXCISION

25. SEQUESTERECTOMY AND CURETTAGE

26. P BEADS BEAD POUCH

27. ANTIBIOTIC CEMENT NAIL

28. OTHERS BIODEGRADABLE ANTIBIOTIC DELIVERY SYSTEMS : Better antibiotic release and compatibility CLOSED SUCTION DRAINS SOFT TISSUE TRANSFER : to fill dead space left behind after extensive debridement ILIZAROV TECHNIQUE ADJUNCTIVE THERAPIES : Hyperbaric oxygen therapy , BMPs , PRP ; ability to accelerate or enhance osteogenesis

29. ILIZAROV TECHNIQUE

30. CLOSED SUCTION DRAINS

31. THANK YOU