Postoperative Glycemic Deterioration and Outcomes After Total Knee Arthroplasty: Does It Matter?

Introduction: The prevalence of knee osteoarthritis and the annual incidence of total knee arthroplasty (TKA) continue to rise. A substantial proportion of TKA candidates have diabetes mellitus, which is associated with increased perioperative risk. Prior studies have largely focused on preoperative hemoglobin A1c (HbA1c), while the effect of postoperative glycemic control on complication rates remains less well defined. This study evaluated the relationship between late postoperative HbA1c levels and postoperative complications following TKA. Materials and Methods: A propensity score–matched retrospective cohort study was performed using the TriNetX multi-institutional database. Adults aged 18–90 years who underwent primary TKA with documented HbA1c greater than 8% 3m -1y preoperatively, who were able to decrease it to under 7.5% <3m preoperatively. HbA1c values obtained 1–2 years postoperatively were used to define cohorts: cohort 1 (HbA1c <7.5%) and cohort 2 (HbA1c ≥8.0%). Outcomes included early medical complications (30- and 90-day) and arthroplasty-specific complications within five years, including periprosthetic joint infection, revision surgery, mechanical loosening, and periprosthetic fracture. Results: After matching a total of 3,200 patients met the inclusion criteria, with 1,600 patients in each cohort after matching. There were no significant differences in 30- or 90-day medical complications between groups. At five years, rates of periprosthetic joint infection, revision surgery, mechanical loosening, and periprosthetic fracture were also similar. Conclusion: Elevated postoperative HbA1c at 1–2 years following TKA was not independently associated with increased risk of complications or implant failure when perioperative glycemic control was optimized. These findings suggest that once early healing occurs under adequate glycemic conditions, later deterioration in glycemic control may have a limited impact on arthroplasty outcomes.