surgical site infection

1. SURGICAL SITE INFECTION
DR.AKHIL JOSE

4. • Surgical site infections (SSIs) are defined as
infections occurring up to 30 days after
surgery (or up to one year after surgery in
patients receiving implants) and affecting
either the incision or deep tissue at the
operation site

8. Patient factor
– Risk factors
• host immunodeficiency
• extremes of age
• diabetes
• obesity
• alcohol or tobacco abuse
• steroid use
• malnutrition
• medications
• previous radiation
• vascular insufficiency

9. Modifiable patient risk factors
(acc to international journal of orthopedic sciences)
• . Diabetes mellitus
• Obesity
• Malnutrition
• Rhuematoid arthritis
• Corticosteroids
• Methotrexate and other DMARD’s
• HIV,UTI
• Cigarette smoking
• Anaemia
• Timing of dental procedures

19. • Fungal infections in immunocompromised
individuals involves
• aspergillus species
• Candida albicans

20. Staphylococcus aureus
• Two strains of S aureus that cause orthopaedic SSI are the
methicillin sensitive and MRSA.
• colonize skin surface of about one third of the general population
• Nasal carriage is the commonest site of colonisation of S aureus and
is strongly associated with skin carriage and such patients are two
to nine times more likely to develop SSI
• only independent risk factor in orthopaedic SSI
• Nasal screening has shown to detect 66% of carriers and combined
nasal and perineal swabs have improved detection rates up to 82%
• .The most commonly used protocol is topical intranasal mupirocin
ointment twice daily and chlorhexidine body washes for 5 days
immediately before surgery along with preoperative antibiotic
prophylaxis
• patients with MRSA additionally receive Vancomycin

24. • Superficial incisional SS Infection
• must occur within 30 day after any operative procedure and involve
only the skin and subcutaneous tissue of incision.
• The patient must also have one of the following:
• (1) Purulent drainage from superficial incision
• (2) Organisms identified from an aseptically obtained Specimen
• (3) Superficial incision that is deliberately opened by a surgeon or
other designee and culture or non culture-based testing is not
performed, and at least one of the following signs or symptoms:
pain or tenderness; localized swelling; erythema; or heat.
• (4) Diagnosis of a superficial incisional SSI by the surgeon or an
attending physician or other designee

27. • Deep incisional SSI Infection must occur within 30 or 90 day after
the operative procedure and involve deep soft tissues of the
incision (fascial and muscle layers).
• The patient must also have at least one of the following: (1)
Purulent drainage from the deep incision
• (2) A deep incision that spontaneously dehisces or is deliberately
opened or aspirated by a surgeon, attending physician, or other
designee, and the organism is identified by a culture or non culture
based microbiologic testing method. The patient must also have
one of the following: fever, localized pain, or tenderness.
• (3) An abscess or other evidence of infection involving the deep
incision that is detected on gross anatomic or histopathologic
examination or imaging test

36. PRESENTATION
– History
• history of trauma must be detailed
– extent of soft tissue injury
– extent of bony injury
– previous or current hardware
– previous or current surgery at the same site
– history of previous skin or deep infections
– Symptoms
• pain at previous fracture site
– may indicate infected non-union
• fevers, chills, and night sweats may be present
– Physical exam
• inspection
– erythema, drainage, or purulence
– tenderness
• motion
– gross motion at fracture site is suggestive of non-union

38. • IMAGING
– Radiographs
• recommended views
– biplanar images of affected area
– 45 degree orthogonal views can also be obtained to evaluate for
union
• findings
– acute infection
» radiographs may be normal
» The initial loss of fat planes is followed by signs of osteomyelitis
appearing 7 to 10 days later
» The effects of surgery such as cortical irregularity and periosteal
reaction can mimic osteomyelitis on radiographic findings.
» Periprosthetic lucency on radiographs also can be due to aseptic
loosening or sub-acute and chronic infections

40. Implant loosening secondary to
infection

41. INVOLCRUM-reactive bone surrounding active infection

42. SEQUESTRUM-retained nidus of infected necrotic bone

43. • Arthrography with either ultrasono graphic or
fluoroscopic guidance can help evaluate joint
infections

44. – CT
• indications
– pre-operative planning
– facilitates visualization of subtle erosive changes and periosteal
reaction in acute osteomyelitis and bony sequestrae in chronic
osteomyelitis that can be masked by postoperative changes and
hardware on radiography
– Intravenous contrast material may help define focal sinus tracts and
abscess which typically demonstrate thick, sometimes irregular rim
enhancement although MRI better delineates soft tissue infections

46. MRI
• Currently, MRI is the premier modality for diagnosing
postoperative infection because of
1. superior soft-tissue contrast
2. inherent ability to define the anatomic extent of osseous
and soft tissue infection.
3. to differentiate simple cellulitis from more complicated
soft-tissue and/or osseous infection
4. . Gadolinium-enhanced, fat-suppressed TI-weighted
sequences can distinguish between edematous and
necrotic tissue and can identify the presence and extent
of fluid collections and sinus tracts
• . Absence of signal abnormality on STIR images virtually
excludes the presence of infection

47. • MRI may be vitally important in the detection of an
intraosseous abscess, which frequently requires
surgical debridement rather than simple intravenous
antibiotic therapy sensitivity and specificity
• DRAWBACK-. Artifacts can be reduced with implants having lower
ferrous content and afield strength of 1.5T or less

50. – WBC-labeled scans
• can help determine infection from other similar
appearing etiologies
• helpful to detect bony infection in the setting of
hardware

52. DIAGNOSTIC STUDIES
– Labs
• WBC
– may be normal in chronic or indolent infections
• erythrocyte sedimentation rate (ESR)
– may remain elevated for months following initial injury or surgery in
absence of infection
• C-reactive protein (CRP)
– most predictive for postoperative infection in the first week after fracture
fixation
•
– should decrease from a plateau after postoperative day 2 (after fixation
of fractures)
•
» will increase further or fail to decrease if a hematoma or infection is
present

56. – Cultures
• in-office cultures swabs or aspirations of wounds or
sinus tracts are unreliable
• intraoperative deep cultures are most reliable method
of isolated causative organisms.
• multiple specimens from varying locations should be
obtained

59. Prevention of SSI
• 1. MRSA Screening and Intranasal Mupirocin
• 2. Preoperative Bathing
• 3. Hair Removal
4. Glycemic control
• 5. Perioperative Antibiotic Prophylaxis
• 6. Surgical Site Skin Preparation
• 7. Laminar Flow Ventilation Systems
• 8. Control Traffic in OR
• 9. Incisional Wound Irrigation
• 10. Perioperative Oxygenation

60. Prevention of SSI

68. TREATMENT
– Nonoperative
• chronic suppression with antibiotics
– indications
» risk of surgical treatment outweighs the benefit to the
host
• immunosuppressed, elderly, etc.
» presence of an infected but incompletely healed fracture
following internal fixation
– technique
» ESR and CRP levels used to assess adequacy of treatment
– outcomes
» 32% rate of chronic infected nonunion persisting or
worsening despite suppression

69. Criteria for patients to be considered for treatment of
orthopedic device–related infections with salvage of
implant.

72. • Moderate evidence supports that rifampin, as
a second antimicrobial, increases the
probability of treatment success for
staphylococcal infections in the setting of
retained orthopaedic implants.

73. Operative
• surgical debridement
– indications
» any active infection
– technique
» hardware should be maintained if stability at risk with
removal
» low-pressure irrigation with normal saline may be superior
to other methods of irrigation
» thorough identification and debridement of infection key to
success
» deep bony specimens should be obtained for culture as well
as biopsy
– outcomes
» 71% success seen with debridement and antibiotics for early
acute postoperative infection .Risk factors for failure include
intramedullary nail and open fracture

77. • According to a retrospective cohort study
including Study group, 311 patients with deep
SSI; control group, 608 patients,
• They evaluated 27 factors theorized to be
associated with postoperative infection

78. E
A Predictive Score for Determining Risk of Surgical Site Infection after
Orthopaedic Trauma Surgery. PMID: 31188262 J Orthop Trauma. 2019 May 21; Epub 2019 May
21
• The final model consisted of 8 independent predictors:
• 1) male sex,
• 2) obesity (body mass index ≥30)
• 3) diabetes,
• 4) alcohol abuse,
• 5) fracture region,
• 6) Gustilo-Anderson type III open fracture,
• 7) methicillin-resistant Staphylococcus aureus nasal
swab testing (not tested or positive result)
• 8) American Society of Anesthesiologists classification.

79. • Risk strata were well correlated with observed
proportion of SSI and resulted in a percent risk of
infection of
• 1% for ≤3 points,
• 5% for 4 points,
• 6% for 5 points,
• 10% for 6 to 8 points,
• 17% for 9 points,
• 41% for ≥10 points

80. Surgical Site Infection In Orthopaedic Implants And Its Common Bacteria
With Their Sensitivities To Antibiotics, In Open Reduction Internal Fixation(J
Ayub Med Coll Abbottabad 2017 Jan-Mar;29(1):50-53
• Results: A total of 132 patients of long bone fractures, who
were treated with open reduction and internal fixation,
were studied. Only 7 patients developed infection.
Staphylococcus Aureus was isolated from all 7 patients.
Staphylococcus aureus was sensitive to Linezolid, Fusidic
Acid, and vancomycin. Cotrimoxazole, tetracycline,
Gentamycin and Clindamycin were partially effective.
• Conclusions: Surgical Site Infection is common in
orthopaedic implants, occurring in 5.30% cases.
Staphylococcus aureus is the common bacteria, causing it.

81. REFERENCES
• Campbell’s Operative Orthopaedics 14th
edition (2021)
• Apley's System of Orthopaedics and Fractures
• Bailey & Love's Short Practice of Surgery, 27th
Edition
• https://pubmed.ncbi.nlm.nih.gov/
• https://www.orthobullets.com/