Van Schuyver, Paul R

Background: There has been minimal literature evaluating how a prior myocardial infraction (MI) influences outcomes after total knee arthroplasty (TKA). Thus, the purpose of this study was to evaluate how the timing, type, and treatment of MI prior to TKA affect postoperative cardiac complications, general medical complications, and surgical complications. Methods: A retrospective comparative study was conducted using a large insurance database. Patients undergoing primary TKA for osteoarthritis were included. Patients who had experienced MI within 2 years before TKA were identified and were matched 1:4 with patients who had not had such an MI on the basis of demographic variables and comorbidities. Patients who had a prior MI were stratified into 4 groups based on the timing of the MI: 0 to <6 months, 6 to <12 months, 12 to <18 months, and 18 to 24 months before TKA. The rates of postoperative cardiac, general medical, and surgical complications were compared between groups. Subanalyses on the prior MI type, treatment, and location were performed. Results: Prior MI was associated with increased risks of postoperative MI (odds ratio [OR], 3.97 [95% confidence interval (CI), 3.20 to 4.93]), heart failure (OR, 1.45 [95% CI, 1.24 to 1.75]), and 90-day mortality (OR, 2.15 [95% CI, 1.41 to 3.28]). The risk of postoperative MI was highest for those with MI within 6 months before TKA (OR, 6.86 [95% CI, 5.34 to 8.82]). Type-1 MI, ST-elevation MI (STEMI), non-ST-elevation MI (NSTEMI), and anterior and inferior MIs were linked to elevated postoperative MI and/or mortality risks, with timing closer to surgery further amplifying the risk. Percutaneous coronary intervention within 6 months before TKA also increased postoperative risks. Type-2 MI within 6 months before TKA was associated with an increased risk of periprosthetic joint infection compared with controls (OR, 4.23 [95% CI, 1.67 to 10.67]). Conclusions: Patients who had a prior MI, particularly within 6 months before TKA, had significantly elevated risks of postoperative MI, heart failure, and mortality. Outcomes varied by MI type, treatment, and location, with type-1 MIs and STEMIs increasing the postoperative mortality risk. Level of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Background: Although it is well established that the type of organism can be a risk factor for failure in patients with periprosthetic joint infection (PJI), no study to date has examined the impact of the number of positive cultures on treatment outcomes in patients undergoing 2-stage exchange. The purpose of this multicenter study was to determine the prognostic utility of multiple positive cultures at resection as a predictor of failure following reimplantation. Methods: This retrospective multicenter study identified 437 patients with chronic knee PJI who had undergone 2-stage exchange arthroplasty with a minimum of 1 year of follow-up following reimplantation. PJI was defined with use of the 2013 Musculoskeletal Infection Society (MSIS) criteria. Patients with culture-negative PJI were excluded (n = 138). Treatment failure was defined as either any reoperation for infection or PJI-related mortality. Multivariable regression controlling for risk factors for failure after a 2-stage arthroplasty was performed to determine whether ≥2 positive intraoperative cultures at resection can predict outcomes following reimplantation when compared with a single positive culture. Results: Two hundred and ninety-nine patients were included. At a mean follow-up of 6.2 ± 2.6 years, 48 patients (16.1%) experienced failure. Patients who had a failure were more likely to have had a longer interstage interval (p = 0.038) and were also more likely to have had ≥2 positive cultures at the time of resection arthroplasty (95.8% versus 75.3%; p = 0.001). On regression analysis, ≥2 positive cultures at resection was the only variable that was identified as a risk factor for failure following reimplantation in both the univariate (odds ratio [OR], 7.55 [95% CI, 2.24 to 47.0]; p = 0.006) and multivariable models (OR, 8.12 [95% CI, 2.31 to 51.9]; p = 0.005). Conclusions: This is the first study to examine the impact of the number of positive cultures on outcomes in patients with PJI. We found that the presence of ≥2 positive cultures at resection was an indicator of a poor prognosis and resulted in a greater than eightfold increase in the risk of treatment failure in patients undergoing a 2-stage exchange. Level of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Abstract ➤ The COVID-19 pandemic created a persistent surgical backlog in elective orthopedic surgeries. ➤ Artificial intelligence (AI) uses computer algorithms to solve problems and has potential as a powerful tool in health care. ➤ AI can help improve current and future orthopedic backlogs through enhancing surgical schedules, optimizing preoperative planning, and predicting postsurgical outcomes. ➤ AI may help manage existing waitlists and increase efficiency in orthopedic workflows.