2. This used to be the dreaded sequelae of AHO
Nowadays it more frequently follows an open #
or operation
Organisms:- with time there is always a mixed
infection
Staph aureus, E-coli, Streptococcus pyogenes,
Proteus mirabilis, P-aeruginosa,
With implants:- Staph epidermidis.
3. PREDISPOSING FACTORS
A.H.O- if left untreated it can progress indefinitely
with flare ups.
Host:- Compromised host by scar formation, dead
and dying bone around the focus of infection, poor
penetration of new blood vessels and collapsing
cavities which the microbes can thrive.
Bacteria:- covered with a protein polysaccharide
slime (glycocalyx) that protect them from host
defenses and antibiotics.
4. • Metal implants.
• Very old or debilitated.
• Those suffering from substance/drug abuse.
• Dm.
• Peripheral vascular dx.
• Skin infection.
• Malnutrition.
• Systemic lupus erythematosus.
• Any type of immunodeficiency.
Common predisposing factors:
• Local trauma e.g. open #s or prolonged bone
operation with use of implants.
5. PATHOLOGY
Bone is destroyed or devitalised.
Cavities containing pus & pieces of dead bone
(sequestra) are surrounded by vascular tissue and
beyond that by areas of schlerosis- chronic new
bone formation may form a distinct bone sheath
(involucrum).
It may be a sizeable length.
Sequestra act as a substance for bacterial adhesion
as well as foreign implant- ensuring the presence of
infection until they are removed or discharged
through a perforation in the involucrum & sinuses
that drain to the skin.
May result in pathological fractures.
6. C/FS
• Pain.
• Pyrexia.
• Redness & tenderness during a flare.
• Discharging sinus.
• Excoriation of surrounding skin.
7. IMAGING
X-ray findings;
• Bone resorption.
• Loss of density with thickening & schlerosis of
surrounding bone.
• Sometimes bone is crudely thickened and
mishapen resembling a tumor.
Sinogram-done to localize infection.
Ct & mri are valuable in planning operation.
Show extend of bone destruction and reactive
edema, hidden abscess, & sequestra.
8. INVESTIGATIONS(LAB)
• Raised ESR & WBC levels.
• Sinus swab for culture & sensitivity.
STAGING C.O.M IN LONG BONES.
• Staging the condition help in risk benefit
assessment.
10. Host type
Type A Normal
Type B Compromised by local or systemic
conditions.
Type C Severely compromised by local & systemic
conditions.
11. • Stage 1 or 2 type A: described by localized
infection & free of compromising disorders-
benefit.
• Stage1-3: have reasonable chance of recovery
– Type C: prognosis is poor. Severely compromised
immunity.
• Stage 4: e.g. in an united fracture. Long term
palliation. Operative rx may be
contraindicated. Advise on amputation.
12. TREATMENT
ANTIBIOTICS
• Chronic infection is seldom eradicated by
antibiotics alone.
• Suppress infection and prevent spread to healthy
bone.
• To control flares;
– Fusidic acid.
– Clindamycin.
– Teicoplanin in methicillin resistant staph-aures.
– 4-6 weeks starting after debridement.
13. LOCAL RX
• Sinus may be painless & need dressing to protect clothing.
• Colostomy paste stop excoriation of skin.
• Abscess need Incision & drainage.
OPERATION:
• INDICATION FOR RADICAL SX.
a. Failure of adequate antibiotic rx .
b. Or evidence of sequestra or dead bone.
c. Posttraumatic; intractable wound &/or infected un-united #.
d. Presence of foreign implant.
14. DEBRIDEMENT
• Dead soft tx.
• Dead bone.
• Implant.
• Inspect after 3 or 4 days for repeat.
• Ct antibiotics for 4 weeks after.
• Dead space-porous antibiotic impregnated beads
for 2-3 weeks.
• Replaced with cancellous bone graft/ muscle flap
transfer.
• Then skin graft the defect.
15. Dead space management
1. Antibiotic beads.
2. External fixator.
3. Bone lengthening.
4. Graft.
5. Vascular graft.
16. In refractory cases it may be possible to excise
the infected or devitalized segment of bone
completely & then close the gap by Illizarov
method of transporting a viable segment from
the remaining diaphysis.
Soft tissue cover;
• Small defect-skin graft
• Musculocutaneous flap or free vascularised
flap
Aftercare; focus of infection may escape the rx
and develop full OM years later.
