CHRONIC OSTEOMYELITIS

1. CHRONIC
OSTEOMYELITIS
DR RITESH JAISWAL
M.B.B.S D.Ortho DNB (Ortho) M.N.A.M.S M.Ch (Ortho)
Fellowship in Joint Replacement ( Mumbai )
Fellow AO Trauma ( Switzerland )

2. INTRODUCTION
Severe, persistent & incapacitating infection of bone and bone marrow
Characterized by :
- Infected dead bone within a compromised soft tissue envelope
- Infected foci within bone are surrounded by sclerotic, relatively
avascular bone covered by a thickened periosteum and scarred
muscle and subcutaneous tissue
- This avascular envelope of scar tissue leaves systemic antibiotics
esssentially ineffective

3. PATHOGENESIS
Due to inadequate treatment of Acute OM or Trauma or Implant/foreign body
↓
Continues inflammatory process with time together with persistent infection
( Commonly with Staph aureus )
↓
Increase intramedullary pressure due to inflammatory exudate ( Pus )
stripping the periosteum
↓
Vascular thrombosis
↓
Bone Necrosis
( SEQUESTRUM )
↓
New bone formation
( INVOLUCRUM )
↓
Discharge of pus, debris & exudates from involucrum through sinuses
k/a CLOACAE

5. PATHOLOGICAL FEATURES OF CHRONIC OM :
- the presence of necrotic bone
- the formation of new bone
- the exudation of polymorphonuclear leukocytes joined by large
numbers of lymphocytes, histiocytes, and occasionally plasma
cells.
- New bone forms from surviving fragments of periosteum and
endosteum in the region of the infection.
- It forms an encasing sheath of live bone, known as an
involucrum, surrounding the dead bone under the periosteum.
- The involucrum is irregular and is often perforated by openings
through which pus may track into the surrounding soft tissues
and eventually drain to the skin surfaces, forming a chronic
sinus.

6. - The involucrum may gradually increase in density and
thickness to form part or all of a new diaphysis.
- New bone increases in amount and density for weeks or
months, according to the size of the bone and the extent and
duration of the infection.
- Endosteal new bone may proliferate and obstruct the
medullary canal.
- After host defense or operative removal of the sequestrum,
the remaining cavity may fill with new bone, especially in
children.
- However, in adults, the cavity may persist or the space may be
filled with fibrous tissue, which may connect with the skin
surface by means of a sinus tract

7. SEQUESTRUM
Term exclusively used in osteomyelitis and is a fragment of
necrotic bone ( usually cortical ) found at the nidus of
infection within bone. These fragment usually begin as part
of the cortex and are surrounded by pus and grannulation
tissue.
INVOLUCRUM
When reactive bone is newly formed at the
interface between diseased bone and healthy
tissue. Radiologically, it appears as newly formed
radiodense bone around the radiolucent sequestrum
CLOACA
Opening in involucrum through which pus and sequestra
make there way out

9. GROSS CHARACTERISTICS OF SEQUESTRUM
- White, brittle bone piece with smooth pus
facing and rough grannulation facing surface
lying free from parent bone
- No punctate bleeding
- Sinks in water
- Dull note on percussion
- Closed haversian canal

11. TYPES OF SEQUESTRUM
1) TUBULAR – Pyogenic sequestrum in children
2 ) FEATHERY - Pyogenic infection
3 ) COARSE SANDY - Tuberculosis
4) DENSE IVORY - Syphilis
5) RING - Pin tract infection
6) BOMBAY SEQUESTRUM ( Black ) - Calcaneum OM
7) KISSING SEQUESTRUM - TB Spine
8) CONICAL SEQUESTRUM - Amputation Stump

12. BIOFILM
- Aggregates of microorganisms in which cells adhere
to each other on a surface.
- These adherent cells are frequently embedded within
a self - produced matrix of extracellular polymeric
substance composed of extracellular DNA, proteins
and polysaccharides .
- It protects bacteria from phagocytosis , recognition &
helps to cling to inert implant material and form
numerus colonies.
- It inhibits T lymphocyte proliferation , B Lymphocyte
blastogenesis , immunoglobulin production ,
interferes with cell chemotaxis , and white cell
degranulation

13. Biofilm bacteria exists in 2 forms :
1) Planktonic state
2) Stationary state

14. CLASSIFICATION

15. CIERNY & MADER CLASSIFICATION

18. CLINICAL PRESENTATION
A) SILENT PHASE ( PERIOD OF INACTIVITY )
- Usually no symptoms
- Overlying skin thin, scarred , poorly
nourished
- Poor healing Ulcerations of skin
- Scarring of muscles with contractures of
surrounding joints

19. B) ACTIVE PHASE ( PERIOD OF ACTIVITY )
- Local inflammatory signs present
( swelling, reddness, warmth, tender )
- Fever mostly lowgrade
- Aching mainly on wt bearing
- Discharging sinus ( draining pus with or
without small pieces of bone )

20. - Disease showing flare ups with intervals of
months to week
- Due to poor general condition & low
resistance
- Recurrent toxemia cause debilitary sometimes
fatal amyloidosis

21. - Patient usually have H/O acute OM
- Chronic OM usual presenting Features are :
- long standing discharging sinus
- Bone pain
- Pathological #

22. O/E
- Drainage of pus
- Small pieces of sequestra through sinus
( hallmark of Chronic OM )
- Protruding grannulation tissue through sinus
- Sinus often adherent to underlying tissue
- Deformity of limb
- Muscle contracture
- LLD

24. DIAGNOSIS
PHYSICAL EXAMINATION
- Check for
- Integrity of skin & soft tissue
- Bone Stability
- Neurovascular status

25. LAB :
- Nonspecific
- ESR, CRP Elevated in most patients
- WBC Elevated only in 35 %

26. RADIOGRAPH
- Osteolytic area
- Bone Resorption
- Thickening & Sclerosis of surrounding bone
- Sequestrum ( Denser than normal bone ) can
be seen inside cavity
- Sinogram is useful in planning surgery

28. CT SCAN
- Provides excellent
definition of cortical
bone
- Evaluation of the
surrounding soft
tissues
- useful in identifying
sequestra.

29. MRI
- Provides extent of the pathological
involvement by showing the margins of bone
and soft-tissue edema.
- May reveal a well-defined rim of high signal
intensity surrounding the focus of active
disease (rim sign).
- Sinus tracks and cellulitis appear as areas of
increased signal intensity on T2-weighted
imaging.

30. BONE SCAN
Technetium-99m bone scans –
- ↑ uptake in areas of increased blood flow or osteoblastic activity.
- Lacks sensitivity
- High negative predictive value
Gallium scans –
- ↑ uptake in areas where leukocytes or bacteria accumulate.
- A normal gallium scan virtually excludes the presence of
osteomyelitis and can be useful as a follow-up examination after
surgery.
Indium-111–labeled leukocyte scans
- more sensitive than technetium or gallium scans
- useful in differentiating chronic osteomyelitis from neuropathic
arthropathy in the diabetic foot.

31. DIFFERENTIAL DIAGNOSIS
- Tuberculous OM
- Soft tissue Infection
- Ewing’s sarcoma

32. TREATMENT
- Chronic OM cannot be eradicated without surgical
treatment.
- Challenges to eradicate the infection only with
Antibiotic
- Adherence of bacteria to orthopaedic implants & bone
- can hide intracellularly.
- slimy coat protecting from phagocytic cells and
antibiotics.
- Goal of surgery is eradication of the infection by
achieving a viable and vascular environment.

33. Debridement :
- Radical débridement may be required to achieve this
goal.
- Inadequate débridement main reason of high
recurrence rate
- Adequate débridement often leaves a large dead
space that must be managed to prevent recurrence
and significant bone loss that may result in bony
instability.
Appropriate reconstruction of the bone and soft-tissue
defects may be needed after proper identification of the
infecting organism and appropriate antibiotic therapy.

34. Reconstruction should be undertaken only after careful
planning and identification of sequestra and intraosseous
abscesses by plain radiographs, sinography, CT, and MRI.
For the reconstructive phases, a plastic surgeon skilled in
coverage techniques, such as skin grafts, muscle and
myocutaneous flaps, and occasionally free flaps should be
consulted.
The duration of postoperative antibiotics is controversial –
practice is to place the patient on 6 weeks of antibiotics,
typically intravenous, under the direction of an
infectious disease specialist, followed by clinical and
laboratory examinations

35. AIMS
1) Adequate debridement
2) Appropriate reconstruction of bone and soft
tissue defect
3) Appropriate antibiotic therapy

36. Sequestrectomy and Curettage
- Sinus tracks can be injected with methylene blue 24 hours before surgery
to make them easier to locate and excise
- Appropriate preparation should be made before surgery as more time to
perform and result in considerably more blood loss.
- Expose the infected area of bone, and excise all sinus tracks completely &
indurated periosteum.
- Use a drill to outline a cortical window at the appropriate site, and remove
it with an osteotome.
- Remove all sequestra, purulent material, and scarred and necrotic tissue
- After removing all suspicious matter, carefully excise the overhanging
edges of bone, and avoid leaving a cavity or dead space.

39. - If a cavity cannot be filled by the surrounding soft tissue, a
local muscle flap or a free tissue transfer can be used to
obliterate the dead space.
- If there is a nonunion present with any bony instability, the
bone must be stabilized, preferably with an Ilizarov-type
external frame.
- If possible, close the skin loosely over drains, and ensure
that no excessive skin tension is present.
- If closure is impossible, pack the wound open loosely or
apply an antibiotic bead pouch, and plan for delayed
closure or skin grafting at a later time
- Appropriate antibiotics should be used before, during, and
after the operation.

40. - The limb is splinted until the wound has healed, and then it is
protected to prevent pathological fracture.
- Bony and soft-tissue defects must be filled to reduce the chance of
continued infection and loss of function.
- Several techniques have been described for the management of
such defects
- Methods described to eliminate this dead space are
(1) bone grafting with primary or secondary closure
(2) use of antibiotic polymethyl methacrylate (PMMA) beads as a
temporary filler of the dead space before reconstruction
(3) local muscle flaps and skin grafting with or without bone grafting
(4) microvascular transfer of muscle, myocutaneous, osseous, and
osteocutaneous flaps
(5) the use of bone transport ( Ilizarov technique )

41. Open Bone Grafting
Papineau technique
This procedure is based on the following principles:
(1) granulation tissue markedly resists infection
(2) autogenous cancellous bone grafts are rapidly
revascularized and are resistant to infection
(3) the infected area is completely excised
(4) adequate drainage is provided
(5) adequate immobilization is provided
(6) antibiotics are used for prolonged periods

42. The operation is divided into three stages:
(1) EXCISION OF INFECTED TISSUE WITHOUT OR WITH
STABILIZATION USING AN EXTERNAL FIXATOR OR AN
INTRAMEDULLARY ROD
(2) In this stage, completely excise the sinus tracks and
sequestra, and saucerize the areas of devitalized
bone.
(3) It sometimes may be necessary to resect the
diaphysis in segments, such as in cases of infected
nonunion
(4) If the demarcation between healthy and infected
tissues is difficult to recognize, repeat this stage at
intervals of 5 to 7 days.
(5) Between the operations, pack the wound open with
dressings soaked in antibiotic, or use an antibiotic
pouch technique

43. (6) If stabilization is required, an external fixator is applied at this
time
(7) Papineau et al. recommended an intramedullary nail for
stabilization.
(8) Delay the next stage until signs of infection are absent, and
healthy-appearing granulation tissue is present throughout.

44. (2) CANCELLOUS AUTOGRAFTING
- This stage consists of autogenous cancellous bone grafting & fill
the cavity completely
- If indicated, use local muscle pedicle grafts to enhance the
blood supply to the grafts, and leave the overlying skin and
subcutaneous tissue open
- Especially in subcutaneous bones such as the tibia, excise the
lips of the wound if the skin tends to cover the granulation
tissue before it completely covers the graft

45. (3) WOUND COVERAGE
In some cases, spontaneous epithelialization
results in adequate wound coverage otherwise,
in stage III use one of several techniques
- skin grafts
- myocutaneous flaps
- muscle pedicle flaps
- free flaps requiring microvascular anastomosis

47. Polymethylmethacrylate Antibiotic Bead Chains
- The use of antibiotic-impregnated PMMA beads in the treatment of chronic
osteomyelitis is common practice.
- The rationale for this treatment is to deliver levels of antibiotics locally in
concentrations that exceed the minimal inhibitory concentrations.
- This has the advantage of obtaining very high local antibiotic concentrations
(200 times), while maintaining low serum levels and low systemic toxicity.
- The antibiotic is leached from the PMMA beads into the postoperative wound
hematoma and secretion, which act as a transport medium.
- High concentrations of the antibiotic can be achieved only with primary
wound closure; if such closure cannot be performed, the wound can be
covered with a water-impermeable dressing (bead pouch technique).
- Before the beads are implanted, all infected and necrotic tissue should be
adequately débrided surgically, and all foreign material should be removed.

48. - Suction drains are not recommended because the concentration level of the
antibiotic is diminished when they are used.
- Aminoglycosides are the most commonly employed antibiotics for use with
PMMA beads.
- Penicillins, cephalosporins, and clindamycin are eluted well from PMMA
beads; vancomycin elutes much less effectively.
- Antibiotics such as the fluoroquinolones, tetracycline, and polymyxin B are
broken down during the exothermic process of cement hardening and cannot
be used with PMMA beads.
- Porous, high-viscosity cements, by providing greater surface area, may allow
antibiotics to elute more readily than less porous cements.
- Currently, most commercially available bone cements have a prepackaged
form available with gentamicin (500 mg per 40 g pack).
- Add 2 to 4 g of vancomycin to each pack because methacillin-resistant S.
aureus is the most common bacterium that can be seen in this setting.

49. - Short-term, long-term, or even permanent implantation of PMMA
antibiotic beads is possible.
- In short-term implantation, the beads are removed within 10 days, and
in long-term implantation, they may be left for 80 days.
- We recommend removal of PMMA beads at about 6 weeks.
- The rationale for removal of PMMA beads is based on numerous
factors.
- Local bactericidal antibiotic levels last only 2 to 4 weeks after
placement, and when all the antibiotic has leached out of the bead, a
foreign body remains that may be colonized by glycocalyx forming
bacteria.
- PMMA also has been shown to inhibit local immune response by
impairing various phagocytic immune cells.
-

50. - The antibiotic bead pouch technique, described
subsequently, has been used with encouraging results for
preventing infection in open fractures.
- It also can be used in the treatment of osteomyelitis if soft-
tissue coverage is impossible after initial débridement.
- The bead pouch must be changed frequently, and repeat
débridement should be performed until the wound is ready
for a soft-tissue coverage procedure.

51. TECHNIQUE
- Thoroughly débride all necrotic tissue & Irrigate
the wound using a pulsatile lavage system with 9
L of saline solution containing bacitracin.
- Prepare antibiotic PMMA beads by mixing high-
viscosity bone cement powder with a powder
form of the antibiotic in a bowl.
- Add the activating solution, and stir the mixture
until the cement is workable.
- Form several beads by rolling them into small
spheres.
- Place the beads on an 18-gauge or 20-gauge wire
to form a bead chain.

52. - Allow the cement to harden. Place the PMMA
antibiotic bead chains into the bony defect filling the
dead space.
- Close all wound extensions with interrupted nylon
sutures.
- Apply an adhesive porous polyethylene wound film
(Op Site) to cover the wound.
- The limb should be appropriately immobilized.
- The bead pouch should be changed at 72-hour
intervals with repeat débridement and irrigation until
the wound is ready for a soft-tissue coverage
procedure

55. Ilizarov Technique
- The Ilizarov technique has been helpful in the treatment of
chronic osteomyelitis and infected nonunions.
- This technique allows radical resection of the infected
bone.
- A corticotomy is performed through normal bone proximal
and distal to the area of disease.
- The bone is transported until union is achieved.
- Disadvantages of this technique include the time required
to achieve a solid union and the high incidence of
associated complications.

56. Hyperbaric Oxygen Therapy
- Hyperbaric oxygen therapy is another method for treating
chronic osteomyelitis, but has not proved to be reliably
effective.
- The use of hyperbaric oxygen can be recommended only as an
adjuvant to more traditional methods of treatment

62. COMPLICATIONS
1) Pathological Fracture
2) Deformity
3) Limb Length Discrepancy
4) Muscle Fibrosis
5) Malignant Changes
- Squamous cell carcinoma of sinus tract
- Osteosarcoma
6) Amyloidosis

63. THANKS
FOR YOUR
ATTENTION