Managing the Infected TSA: P. Acnes and Other Frustrating Issues - - PowerPoint PPT Presentation

Managing the Infected TSA: P. Acnes and Other Frustrating Issues

Eric T. Ricchetti, MD Ortho Summit 2017: Evolving Techniques Las Vegas, NV December 8, 2017

I have something to disclose.

Detailed disclosure information is available via: “My Academy” app; Printed Final Program; or AAOS Orthopaedic Disclosure Program on the AAOS website at http://www.aaos.org/disclosure

My Academy

The Challenge

Topolski et al, JSES 2006; Kelly & Hobgood, CORR 2009; Foruria et al, JSES 2013 Piper et al, J Clin Micro 2009; Singh et al, JSES 2012; Pottinger et al, JBJS 2012; Ricchetti et al, JBJS Reviews 2014; Grosso et al, JSES 2012; Grosso et al, JSES 2014; Frangiamore et al, JBJS 2015 (a & b); Frangiamore et al, JSES 2015

• P. acnes is the most common

pathogen in revision shoulder arthroplasty.

• Revision shoulder arthroplasty ~50%

positive culture rate

• Due to its indolent nature,

infection can be difficult to evaluate, diagnose, and treat.

• Subtle, non-specific clinical picture

with delayed, chronic presentation

• Pain ± stiffness

Evaluation

• Diagnostic work-up of a

painful shoulder arthroplasty:

• History & Physical
• Imaging
• Serum ESR & CRP
• Preoperative aspiration
• Intraoperative culture &

pathology

• Not overtly positive in

many cases.

Evaluation

• Risk factors for PJI of the

shoulder:

• Male gender (P. acnes)
• Postoperative hematoma
• Prior shoulder surgery (non-

arthroplasty, arthroplasty)

• Age
• Humeral and/or glenoid

component loosening,

• steolysis (early)

Cheung et al, JBJS 2008; Singh et al, JSES 2012; Pottinger et al, JBJS 2012; Richards et al, CORR 20014; Hou et al, JSES 2015; Nelson et al, JSES 2016; Werthel et al, JSES 2016

• Low sensitivity of standard serum

markers due to indolent pathogens, but good specificity:

• Serum ESR sensitivity & specificity:
• Hip & knee PJI: 75-89%, 69-74%
• Shoulder PJI: 21-42%, 65-93%
• Serum CRP sensitivity & specificity:
• Hip & knee PJI: 74-97%, 74-97%
• Shoulder PJI: 0-63%, 73-95%

6

Piper et al, PloS ONE 2010; Berberi et al, JBJS 2010; Jacovides et al, J Arthroplasty 2011; Deirmengian et al, JBJS 2014; Villacis et al, JBJS 2014; Grosso et al, JSES 2014

Preoperative Serum Markers

• No standardized protocol for preoperative &

intraoperative culture sampling & analysis:

• Under sampling common in literature.
• Factors impacting P. acnes recovery:
• Preoperative antibiotic hold
• Fluid vs. periprosthetic tissue specimens
• Culturing technique (anaerobic, implant sonication)
• Culture length: 7-28 days
• Optimal intraoperative culture protocol:
• Ability to interpret significance of a positive

culture result: true positive vs. contaminant.

• 4-5 tissue specimens, 14-17 day culture hold

Piper al, J Clin Micro 2009; Butler-Wu et al, J Clin Micro 2011; Pottinger et al, JBJS 2012; Matsen et al, JBJS 2013; Mook et al, JBJS 2014; Hou et al, JSES 2015; Hsu et al, JBJS 2016; Ahsan et al, JBJS 2017

Culture Analysis

• Frangiamore et al, JBJS 2015: Evaluated 46 revision

shoulder arthroplasty cases with ≥1 P. acnes positive culture

• Two culture groups based on periprosthetic shoulder

infection criteria:

• Probable true positive group
• Probable contaminant group
• Time to culture growth significantly shorter in probable true

positive culture group (median, 5 vs. 9 days, p=0.002).

• Regardless of group classification, significantly fewer days to
• P. acnes culture growth:
• Cases with higher number of positive cultures
• Case with higher proportion of positive cultures

Significance of Positive Culture

• Even if diagnosis of PJI can clearly be

made, treatment algorithm still not clearly defined in chronic indolent setting:

• Diagnosed before or at time of surgery:
• One-stage revision arthroplasty with

postoperative antibiotics

• Two-stage reimplantation
• Diagnosed after post-op culture growth:
• One-stage revision arthroplasty
• Need for and length of post-op antibiotics

Treatment

• Nelson et al, JSES 2016: Systematic review of
• utcomes in treatment of shoulder PJI
• 30 studies, 669 patients
• P. acnes most common bacteria (38.9%)
• PJI eradication rates:
• Resection arthroplasty: 93.3% (n=90)
• Antibiotic spacer only: 90.3% (n=31)
• One-stage with UPC: 90.1% (n=282)
• One-stage without UPC: 91.7% (n=72)
• Two-stage: 93.8% (n=97)
• Antibiotic suppression: 50% (n=8)
• I&D with implant retention: 68.6% (n=35)

Treatment

• Good outcomes & infection

eradication reported with both one- and two-stage revisions, but difficult to draw definitive conclusions:

• Small numbers per study
• Often non-comparative
• Varying treatment protocols
• Varying follow-up
• Lack of uniform criteria for

choosing one- vs. two-stage revision

Ince et al, JBJS Br 2005; Cuff et al, JBJS Br 2008; Beekman et al, JBJS Br 2010; Hattrup & Renfree Orthop 2010; Cofffey et al, JSES 2010; Sabesan et al, CORR 2011; Klatte et al, Bone JJ 2013; George et al, BMC MSK 2016; Nelson et al, JSES 2016; Stone et al, JSES 2017

Treatment

Treatment

• Hsu et al, JBJS 2016: One-stage revision in P.

acnes positive revision shoulder arthroplasty

• Retrospective comparison of clinical outcomes of

cases without evidence of infection at minimum 2 year follow-up (47.8±11.8 months):

• 27 cases with ≥2 P. acnes positive cultures
• 89% male (p<0.001), mean age 63.5±7.2 yrs
• Controls: 28 cases with no or 1 P. acnes positive culture
• 39% male, mean age 67.1±8.1 yrs
• No difference in pain and functional improvement

between groups.

• No difference in revision surgeries between groups, no

revisions for infection.

• Antibiotic side effects in 42% (14/33)

• Two-stage revision: Positive preoperative synovial

aspirate, early humeral loosening, intraoperative gross findings, positive intra-operative frozen sections

• Subset of patients consider one-stage?
• One-stage revision: Negative pre- and intra-operative

work-up

• Discharge on oral antibiotic until cultures final at two weeks
• If late growth of only one positive culture, all other testing is

negative: consider no further treatment if all components removed & used antibiotic cement.

• If early growth of one positive culture or multiple positive

cultures: convert to 6 weeks IV antibiotics ± period of oral antibiotic (duration unknown).

Summary: Treatment Algorithm