Is routine screening of Hemoglobin A1C in primary total knee arthroplasty patients worthwhile?

Abstract

Introduction: Peri-prosthetic joint infection (PJI) is a devastating complication after total knee arthroplasty (TKA). Diabetes and postoperative hyperglycemia is risk factor for PJI. Hemoglobin A1c (HbA1c) is a glycemic marker and correlates with diabetic complications. As dysglycemia are frequently asymptomatic, it is plausible to screen TKA patients with HbA1c. We aim to evaluate results of routine HbA1c screening in identifying undiagnosed pre-diabetes and diabetes and compare prevalence of PJI with historical data. Methodology: Primary TKA from 2009 to May 2018 were reviewed. American Diabetes Association defined pre-diabetes and diabetes as HbA1c 5.7% to 6.4% and >=6.5% respectively. Routine HbA1c screening and Diabetes Optimization program was started in March 2017, newly diagnosed patients or HbA1c >=7.5% were referred for optimization before TKA. All PJI within the studied period were identified and defined according to Musculoskeletal Infection Society working group in 2011. Results and Analysis: Routine HbA1c screening and no screening group consisted of 693 TKAs (576 patients) and 2724 TKAs (1990 patients) respectively. In routine screening group, prevalence of known pre-diabetes and diabetes was 2% and 26.2% respectively, while 36.1% and 1.4% had undiagnosed pre-diabetes and diabetes. Therefore, 37.4% have undiagnosed dysglycemia undergoing TKA and the number needed to screen was 3. Overall prevalence of PJI in routine screening and no HbA1c screening group was 0.3% and 1.0% respectively and was marginally insignificant (p = 0.068). Discussion and Conclusion: Routine HbA1c screening in TKA patients can identify significant proportion of undiagnosed pre-diabetes and diabetes, which provides an opportunity for early treatment and prevention of hyperglycemic complications.