1. Infection in Bone and Joint
Presented By:
Fadel Naim M.D.
Orthopedic Surgeon
IUG

2. Osteomyelitis osteon (bone) myelo (marrow) itis (inflammation)
Inflammation and destruction of bone caused by aerobic and anaerobic bacteria, mycobacteria, and fungi
The term osteomyelitis does not specify the causative organism or the disease process

3. Epidemiology Common in young children
Common with malnutrition, immunodeficiency - with decreased resistance of the patient
Boys> girls
History of trauma
Decreasing in incidence & severity & mortality with advent of newer antibiotics

4. Osteomyelitis Classification: Duration Acute, Subacute or Chronic
Route of infection Hematogenous or Exogenous
Host response Pyogenic or Granulomatous

5. Acute Pyogenic Osteomyelitis
infants
Staphylococcus aureus, Streptococcus agalactiae, Escherichia coli
children over one year
Staphylococcus aureus, Streptococcus pyogenes, and Haemophilus influenzae
adults
Staphylococcus aureus

6. Source Of Infection Hematogenous spread Direct inoculation
Contiguous focus of infection

7. The most common site is the rapidly growing and highly vascular metaphysis of growing bones
The apparent slowing or sludging of blood flow as the vessels make sharp angles at the distal metaphysis
predisposes the vessels to thrombosis
the bone itself to localized necrosis and bacterial seeding

8. The joint is usually spared from infection unless the metaphysis is intracapsular, as is found in the proximal part of:
The radius
The humerus
The femur

9. Age variation Neonates: Extensive bone necrosis
Increased ability to absorb large sequestrum
Increased ability to remodel
Epiphysio-metaphyseal vascular connection
leading to secondary septic arthritis

10. Age variation
Adults:
No subperiosteal abscess due to adherent periosteum
Soft tissue abscess
Vascular connection with the joint leading to secondary septic arthritis

11. Clinical Pictures Pain, restless Malaise and fever
The limb is held still (pseudo paralysis)
Sometimes mild or absent (neonates)

13. Acute Osteomyelitis Diagnosis
History and clinical examination
CBC, ESR, B.C.
X-ray (normal in the first (10-14) days
Ultrasound
Bone Scan Tc 99, Gallium 67
MRI
Aspiration

14. Radiographic Findings
Usually reflect the destructive process but lag at least two weeks behind the process of infection
The earliest changes are:
Swelling of the soft tissue
Periosteal thickening and/or elevation
Focal osteopenia
At least 50% to 75% of the bone matrix must be destroyed before radiographs show lytic changes

15. (A) Proximal humerus at day 1 of infection - no visible changes.
(B) Proximal humerus at day 12 of infection

19. Plain-film radiograph showing osteomyelitis of the second metacarpal (arrow).
Periosteal elevation, cortical disruption and medullary involvement are present.

20. The above X-ray of the left ankle of a 10-year-old boy shows lucency in the tibial metaphysis secondary to acute hematogenous osteomyelitis (AHO).
The above X-ray of the right ankle of a 10-year-old boy shows lucency in the tibial metaphysis secondary to acute hematogenous osteomyelitis (AHO).

21. Here is an X-ray of an AHO lesion extending into the growth plate

22. Show increase activity but it is a non specific sign of inflamation.
Radiological studies
MRI :
Early detection and surgical localization of osteomyelitis.
Sensitivity ranges from %.
Radionuclide bone scanning :
A 3-phase bone scan with technetium 99m is probably the initial imaging modality of choice
Show increase activity but it is a non specific sign of inflamation.

23. This MRI sagittal section shows the same AHO lesions with the right lesion extending into the growth plate.

24. Bone scans, both anterior (A) and lateral (B), showing the accumulation of radioactive tracer at the right ankle (arrow). This focal accumulation is characteristic of osteomyelitis.

25. Labratory
The leukocyte count (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein level (CRP) should be monitored
At the time of admission
During treatment
During follow-up
In all patients with osteomyelitis on a weekly basis

26. Diagnosis requires 2 of the 4 following criteria:
Purulent material on aspiration of affected bone
Positive findings of bone tissue or blood culture
Localized classic physical findings of bony tenderness, with overlying soft-tissue erythema or edema
Positive radiological imaging study

27. Differential Diagnosis
Acute Septic Arthritis
Acute monoarticular rheumatoid arthritis
Sickle cell crisis
Cellulitis
Ewing’s Sarcoma

28. Complications Septicemia & metastatic abscesses Septic arthritis
Growth disturbance (children)
Pathological fracture
Chronic osteomyelitis

30. Subacute Osteomyelitis

31. Subacute Osteomyelitis
Results from a less virulent Microorganism, or a patient with an elevated resistance.
Occurs Mostly at the Distal Femur or Proximal Tibia
On X-Ray: Brodie’s Abcess
Small and Oval in shape
It is surrounded by sclerotic bone
May be mistaken for Ostieoid Osteoma

32. Subacute Osteomyelitis
An image depicting subacute osteomyelitis

33. Chronic Osteomyelitis
The coexistence of infected, nonviable tissues and an ineffective host response leads to the chronicity of the disease

34. Chronic Osteomyelitis
Factors responsible for chronicity
Local factors: Cavity, Sequestrum, Sinus, Foreign body, Degree of bone necrosis
General: Nutritional status of the involved tissues, vascular disease, DM, low immunity
Organism: Virulence
Treatment: Appropriateness and compliance
Risk factors: Penetrating trauma, prosthesis, Animal bite

35. Pathologic features of chronic osteomyelitis Sequestrum:
When both the medullary and the periosteal blood supplies are compromised, large areas of dead bone (sequestra) may be formed
Involucrum:
New bone forms from the surviving fragments of periosteum and endosteum in the region of the infection to form an encasing sheath of live bone
sinus tract:
A bone cavity may persist or the space may be filled with fibrous tissue, which may connect with the skin surface by the sinus tract

36. Sequestrum

37. Chronic Osteomyelitis
Types
A complication of acute Osteomyelitis
Post traumatic
Post operative

39. Chronic Osteomyelitis
Low grade fever, if present
ESR usually elevated, reflecting chronic inflammation
The blood leukocyte count ( WBC ) is usually normal
If a sinus tract becomes obstructed, the patient may present with a localized abscess and/or an acute soft-tissue infection

40. Chronic Osteomyelitis Organism
Usually mixed infection
Mostly staph. Aureus E. Coli . strep pyogen, proteus

41. Treatment of Osteomyelitis
A close interaction between various specialists is important to improve the management of this disease
Orthopaedic surgeons
Plastic and vascular surgeons
Infectious disease specialists

42. Treatment of Osteomyelitis
Adequate drainage
Thorough débridement
Obliteration of dead space
Wound protection
Specific antimicrobial coverage
Correcttion of host defects
Improving the nutritional, medical, and vascular status of the patient
Good nutrition
Smoking cessation
Control of specific diseases such as diabetes

44. Bone Stabilization
If skeletal instability is present measures must be taken to achieve stability with plates, screws, rods, and/or an external fixator.
External fixation is preferred over internal fixation.
Ilizarov external fixation:
allows reconstruction of segmental defects and difficult infected nonunion.
An extended period of treatment with the device, averaging 8.5 months.
The sites of the wires or pins usually become infected and the device is painful.

45. Soft-tissue Coverage
Adequate soft-tissue coverage of the bone is necessary to arrest osteomyelitis
Small soft-tissue defects may be covered with a split-thickness skin graft
For large soft-tissue defects or an inadequate soft-tissue envelope, local muscle flaps and free vascularized muscle flaps may be placed in one or two stages
Healing by so-called secondary intention should be discouraged

46. Septic Arthritis

47. Septic Arthritis Septic arthritis : Reactive arthritis:
Direct invasion of joint space by a variety of microorganisms, including a variety of bacteria, viruses, mycobacteria, and fungi.
Reactive arthritis:
A sterile inflammatory process, may be the consequence of an infectious process located somewhere else in the body.

48. Septic Arthritis 50% of cases in children <3 years
The hip joint is the common site in <3years, whereas the knee joint is more common in older children.

49. 7.8 cases per 100,000 person-years
The incidence of gonococcal arthritis is 2.8 cases per 100,000 person-years
Septic arthritis is becoming increasingly common among people who are immunosuppressed and elderly people who have a variety of co-morbid diagnoses

50. Most of these infections occur in very young and very old people and among people who abuse intravenous drugs
The most commonly involved joint:
Knee (50%)
Hip (20%)
Shoulder (8%)
Ankle, and wrists (7% each)
Elbow, interphalangeal, sternoclavicular, and sacroiliac joints each make up 1-4% of cases

51. Risk Factors Corticosteroids-33% Existing arthritis-24%
Infection elsewhere-22%
DM-13%
Trauma-12%
None-8%

52. Two major classes :
Gonococcal
Nongonococcal
Neisseria gonorrhoeae remains the most frequent pathogen (75% of cases) among younger sexually active individuals
Staphylococcus aureus is the most common cause of the vast majority of cases of acute bacterial arthritis in adults and children older than 2 years

53. Organisms may invade the joint by:
Direct inoculation
Contiguous spread from infected periarticular tissue
Bacteremia (the most common route)

54. Acute Septic Arthritis Differential Diagnosis
Acute osteomyelitis
Trauma
Irritable joint
Hemophilia
Rheumatic fever
Gout

55. Diagnosis History
Because joint infections are uncommon, be attentive to features of the patient's history that may indicate an infectious process and not a primary rheumatological or orthopedic process

56. Inspection
Thorough inspection of all joints for signs of inflammation is essential for diagnosing infection :
Erythema
Swelling (90% of cases)
Warmth
Tenderness
Limitation of both active and passive ROM

57. Synovial Fluid Examination
Leukocyte count
Appearance on gram stain
Polarizing microscopy examination
Culture of the fluid
Culture of the synovial fluid or of synovial tissue itself is the only definitive method of diagnosing infective arthritis

61. Imaging Studies
Plain radiographs of some limited value in evaluating a joint for infection
Radiographs are most useful in ruling out underlying osteomyelitis or periarticular osteomyelitis resulting from the joint infection itself
Periarticular soft tissue swelling is the most common finding
Ultrasonography may be used to diagnose effusions

62. Acute Septic Arthritis
Treatment
Aspiration
Antibiotics
Splintage
Surgical drainage
Treatment of complications

63. Management of Infective Arthritis
Management of infective arthritis focuses on:
Adequate and timely drainage of the infected synovial fluid
Administration of appropriate antimicrobial therapy
Usually, the antibiotic must be administered parenterally for 3-4 weeks, but each case needs to be evaluated individually
Immobilization of the joint to control pain

64. Drainage
The choice of the type of drainage, whether percutaneous or surgical, has not been resolved completely
Aspirating the joint 2-3 times a day may be necessary during the first few days
Surgical drainage is indicated:
For the appropriate choice of antibiotics
Vigorous percutaneous drainage fails to clear the infection after 5-7 days
The infected joints are difficult to aspirate (eg, hip)
Adjacent soft tissue is infected

65. Prognosis
50% of adults with septic arthritis have significant sequelae of decreased ROM or chronic pain after infection
poor outcome in the following:
Age older than 60 years
Infection of the hip or shoulder joints
Underlying rheumatoid arthritis
Positive findings on synovial fluid cultures after 7 days of appropriate therapy
Delay of 7 days or more in instituting therapy

66. Thank You