The Value of Serological Screening Prior to Conversion Total Hip Arthroplasty

Kyle H Cichos; Matthew C Christie; Alex R Heatherly; Gerald McGwin Jr; Jonathan H Quade; Elie S Ghanem

doi:10.1016/j.arth.2020.02.035

The Value of Serological Screening Prior to Conversion Total Hip Arthroplasty

J Arthroplasty. 2020 Jun;35(6S):S319-S324. doi: 10.1016/j.arth.2020.02.035. Epub 2020 Feb 24.

Authors

Kyle H Cichos¹, Matthew C Christie¹, Alex R Heatherly², Gerald McGwin Jr³, Jonathan H Quade¹, Elie S Ghanem¹

Affiliations

¹ Department of Orthopaedic Surgery, University of Alabama at Birmingham, Birmingham, AL.
² UAB School of Medicine, Birmingham, AL.
³ Department of Epidemiology, UAB School of Public Health, Birmingham, AL.

PMID: 32169386
DOI: 10.1016/j.arth.2020.02.035

Abstract

Background: This study sought (1) to assess the value of serological testing prior to conversion total hip arthroplasty (THA) in predicting infection and (2) to identify optimal serological values for routine diagnostic workup prior to conversion THA.

Methods: All patients at our tertiary referral center undergoing conversion THA after hip/acetabular fracture procedure from 2013 to 2018 were retrospectively reviewed. Inclusion criteria were patients previously undergoing hemiarthroplasty or open reduction and internal fixation of acetabular, intertrochanteric, and subtrochanteric fractures that progressed to conversion THA due to post-traumatic arthritis having erythrocyte sedimentation rate/C-reactive protein (CRP) prior to conversion. Infection was defined as positive intraoperative cultures not deemed contaminant in collaboration with infectious disease consult and/or development of PJI within 1 year postoperatively.

Results: Twelve of 87 (14%) patients undergoing conversion THA developed infection. The mean erythrocyte sedimentation rate (37.2 vs 24.4 mm/h, P = .2062) and CRP (22.4 vs 9.0 mg/L, P = .0026) in the infected cohort were elevated compared to the noninfected group. An optimal cutoff value for CRP of 12 mg/L (area under the curve = 0.77, 95% confidence interval 0.58-0.97) revealed 75% sensitivity, 84% specificity, 43% positive predictive value, and 95% negative predictive value (P < .0001) in the entire cohort.

Conclusions: Even without clinical signs and symptoms, patients undergoing conversion THA from internal fixation of hip/acetabular fractures are still at high risk for developing periprosthetic joint infection. All patients undergoing conversion THA should have CRP measured preoperatively as a part of the diagnostic workup for underlying infection. Further research should be devoted to creating a preoperative diagnostic algorithm incorporating CRP, similar to Musculoskeletal Infection Society criteria, dedicated to patients undergoing conversion THA.

Level of evidence: Level III, Diagnostic retrospective cohort study.

Keywords: CRP; conversion; infection; screening; serology; total hip arthroplasty.

MeSH terms

Acetabulum / surgery
Arthroplasty, Replacement, Hip* / adverse effects
Blood Sedimentation
Humans
Prosthesis-Related Infections* / diagnosis
Prosthesis-Related Infections* / epidemiology
Prosthesis-Related Infections* / etiology
Reoperation
Retrospective Studies