Aggressive Infections In

Patients Treated With

External Fixators

Scott J. Schoenleber, MD

James J. Hutson, Jr., MD

Disclosures

I have no conflicts.

This study was approved by our institutional review board.

Background

• Infections are extremely common in external fixation

– Range 11-97% 4-8

• Vast majority are managed without difficulty 2,4,7,9-10

• Uncommon reports of atypical and aggressive infection

– TSS 11-12

– Necrotizing fasciitis 4

Study Aim

• To describe unusual, rare, and aggressive infections in patients with external fixators

• To identify potential risk factors

• To identify management protocols and correlate with outcomes

Material and Methods

• Single-surgeon database from 1991 to present

– 1166 patients

• Retrospective chart review

INCLUSION

• Any form of ex fix

• Atypical infection as determined by senior author

EXCLUSION

• Standard superficial or deep pin site infection

• Typical osteomyelitis

Demographics

• 12 patients (11 M, 1 F)

• Median age 43.5y (range 16 to 65y)

• No patient treated for isolated deformity

Risk Factors for Severe

Infection Positive response

(of 12)

Open fracture 8

HIV status 0

Smoking status 4

Adult comorbidities 0

TIME IN DAYS RANGE

Mean time from injury to initial tx 1.4

0 to 12 days

Median time from initial to definitive tx 16.0

0 to 354 days

Less severe Atypical Bone or Joint 1. Late

2. Aggressive

Soft Tissue Infection 1. Pan-pin cellulitis

2. Necrotizing fasciitis

Unusual / Aggressive Infection Types

More severe

INFECTION TYPE

1. Atypical late

2. Atypical aggressive

3. Pan-pin cellulitis

4. Necrotizing fasciitis

PRESENTING FEATURES

1. Vague, nonspecific pain/drainage 1+ years after tx

2. Fluctuance, effusion, drainage (aggressive features)

3. Diffuse swelling, erythema, drainage, smokers

4. Severe swelling, purulent drainage, sepsis

Presenting characteristics

Atypical Late Infections • Mean number of debridements: 3.0 / patient

• Mean time from injury to infection: 1162.3 days – Range 204-2056 days

Patient Injury Risk Factors Infection type Number of

debridements Micro-biology Outcome Function

3 G3B tibia Crush Olive wire

abscess 3 MSSA Salvage

Good; required late ankle fusion

5 Closed plateau Acute

definitive tx Late septic knee with recurrence 5

MRSA, recurrent

MRSA

Salvage; knee

arthrodesis Fair

6 G3B tibia 1 PPD

smoker

Intramedullary abscess in

mature regenerate 1

Group A strep Salvage

Good; full work on

motorcycles

Olive wire abscess 3 years after fixator removal, pt previously asymptomatic

Atypical Aggressive Infections

• Mean number of debridements: 4.7 / patient

• Mean time from injury to infection: 59.6 days – Range 46-77 days

Patient Injury Risk Factors Infection type Number of

debridements Microbiology Outcome Function

2 G3B pilon Sewage

contamination Unusual organism 9

M. fortuitum, E. faecalis, E. cloacae Salvage

Good; working

as plumber

4 G3B pilon Delayed

presentation

Recurrent aggressive septic

arthritis 4 MRSA, then

MSSA Death Death

11 G2 tibia Prolonged ICU

stay Hematoma infection 1 MRSA Salvage Good;

full work

Pan-Pin Cellulitis

Patient Injury Risk

Factors Number of

debridements Microbiology Outcome Function

8 G3A pilon 1 PPD

smoker 4

MRSA, MRSA recurrence,

E. Cloacae + A. baumannii Salvage

Poor; debilitating ankle

arthritis

9 G3A tibia

1 PPD smoker,

degloving injury 1 MSSA

Salvage; nonunion

successfully repaired

Good; full work as welder

10 Closed plateau

Severe fracture blisters 6 P. aeruginosa Lost to follow-up Lost to follow-up

• Mean number of debridements: 3.7 / patient • Mean time from injury to infection: 89.3 days

– Range 48-124 days

Necrotizing Fasciitis

Patient Injury

Days from infection to amputation

Number of debridements Microbiology Outcome Function

1 G3B plateau 0 unknown

Leclercia adecarboxylata,

Enterobacter agglomerans, E.

faecalis

Through knee amputation

Good; functional prosthesis

user

7 Closed pilon 2 4 MRSA BKA Good;

working full time

12 Closed

navicular 2 6 MSSA BKA

Good; walking well with

prosthesis

• Mean number of debridements*: 5.0 / patient • Mean time from injury to infection: 35.0 days

• Range 3-68 days • Mean time from infection to amputation: 1.3 d

Microbiology

MRSA 33%

MSSA 19%

Enterococcus faecalis 9%

Enterobacter cloacae 9%

Group A strep 5%

Pseudomonas aeruginosa

5%

Acinetobacter baumannii

5%

Mycobacterium fortuitum 5%

Leclercia adecarboxylata 5%

Enterobacter agglomerans 5%

MRSA

MSSA

Enterococcus faecalis

Enterobacter cloacae

Group A strep

Pseudomonas aeruginosa

Acinetobacter baumannii

Mycobacterium fortuitum

Leclercia adecarboxylata

Enterobacter agglomerans

Patient Outcomes

Amputation

Death Union

Nonunion

Salvage

Amputation

Death

Union

Nonunion

• Injury and infection difficult to delineate

– Severe post-traumatic arthritis

• 8/12 with good function

Conclusions

1. Severe and unusual infections can rarely develop in high-risk patients with external fixators

2. These can be life- and limb-threatening

3. Early, aggressive surgical debridement (including amputation as necessary) is indicated

Thank You

References

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