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Novel Diagnostics in Revision Arthroplasty: Implant Sonication and Multiplex Polymerase Chain Reaction
Published on: December 3, 2017
Unexpected positive cultures in aseptic revision hip and knee arthroplasty
Babar Kayani1,2, Fabio Mancino1,2, Joanna Baawa-Ameyaw1,2
1University College Hospital, London, UK.
Aims:
The outcomes of patients with unexpected positive cultures (UPCs) during revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) remain unknown. The objectives of this study were to establish the prevalence and infection-free implant survival in UPCs during presumed aseptic single-stage revision THA and TKA at mid-term follow-up.
Methods:
This study included 297 patients undergoing presumed aseptic single-stage revision THA or TKA at a single treatment centre. All patients with at least three UPCs obtained during revision surgery were treated with minimum three months of oral antibiotics following revision surgery. The prevalence of UPCs and causative microorganisms, the recurrence of periprosthetic joint infections (PJIs), and the infection-free implant survival were established at minimum five years' follow-up (5.1 to 12.3).
Results:
Of the 297 patients undergoing aseptic revisions, 37 (12.5%) had at least three UPCs obtained during surgery. The UPC cohort included 23 males (62.2%) and 14 females (37.8%), with a mean age of 71.2 years (47 to 82). Comorbidities included smoking (56.8%), hypertension (48.6%), diabetes mellitus (27.0%), and chronic renal impairment (13.5%). The causative microorganisms included Staphylococcus epidermidis (49.6%), Bacillus species (18.9%), Micrococcus species (16.2%), and Cutibacterium acnes (16.2%). None of the study patients with UPCs developed further PJIs or required further surgical intervention during follow-up.
Conclusion:
The prevalence of UPCs during presumed aseptic revision THA and TKA was 12.5%. The most common causative microorganisms were of low virulence, and included S. epidermidis, Bacillus species, Micrococcus species, and C. acnes. Microorganism-specific antibiotic treatment for minimum three months' duration of UPCs in presumed aseptic revision arthroplasty was associated with excellent infection-free implant survival at mid-term follow-up.
Insights
Unexpected positive cultures (UPCs) during revision hip and knee arthroplasty occurred in 12.5% of patients. Low-virulence bacteria were common, and antibiotic treatment led to excellent infection-free implant survival.
Area of Science:
- Orthopedic Surgery
- Infectious Diseases
- Microbiology
Background:
- Outcomes of unexpected positive cultures (UPCs) during revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) are not well-established.
- UPCs can complicate presumed aseptic revision arthroplasty procedures.
Purpose of the Study:
- To determine the prevalence of UPCs in presumed aseptic single-stage revision THA and TKA.
- To evaluate infection-free implant survival in patients with UPCs at mid-term follow-up.
Main Methods:
- A single-center study of 297 patients undergoing presumed aseptic single-stage revision THA or TKA.
- Patients with at least three UPCs received a minimum of three months of oral antibiotics.
- Prevalence, causative microorganisms, periprosthetic joint infection (PJI) recurrence, and infection-free survival were assessed at a minimum of five years' follow-up.
Main Results:
- The prevalence of UPCs was 12.5% (37 of 297 patients).
- Common microorganisms included Staphylococcus epidermidis, Bacillus, Micrococcus, and Cutibacterium acnes, all of low virulence.
- No patients with UPCs developed subsequent PJIs or required revision surgery during follow-up.
Conclusions:
- UPCs occur in 12.5% of presumed aseptic revision hip and knee arthroplasties.
- Low-virulence organisms are frequently identified in UPCs.
- A minimum of three months of targeted antibiotic therapy for UPCs is associated with excellent mid-term infection-free implant survival.
