Is the time to revision surgery after peri-prosthetic fracture of the knee associated with increased rates of post-operative complications?

BACKGROUND: This registry study assesses 30-day outcomes, including complications, length of stay (LOS), transfusions, and discharge disposition, as a function of time to revision surgery for knee periprosthetic fracture (PPF). METHODS: We compared outcomes when surgery occurred ≤ (expedited) or > 24 hours (nonexpedited) after admission using the 2005-2016 National Surgical Quality Improvement Program registry. Outcome variables were assessed using bivariate and multivariate analyses. RESULTS: Of 484 patients undergoing revision knee arthroplasty for PPF, 337 (77.9%) had expedited surgery and 107 (22.1%) had nonexpedited surgery. The average time to surgery in the nonexpedited group was 3.2 days (range 0-11). Patients with nonexpedited surgery were more likely to be older, female, and diabetic, received general anesthesia, and had a higher American Society of Anesthesiologists class, dependent functional status, and longer operative time. On multivariate analysis, nonexpedited patients had more complications (odds ratio [OR], 2.35; P = 0.037), surgical site infections (OR, 12.87; P = 0.029), urinary tract infections (OR, 10.46; P = 0.048), nonhome discharge (OR, 4.27; P < 0.001), need for blood transfusion (OR, 4.53; P < 0.001), and longer LOS (2.4 days; P < 0.001). There was no difference in mortality (P = 0.352). CONCLUSIONS: Nonexpedited revision surgery for knee PPF had worse outcomes, specifically more surgical site and urinary tract infections, longer LOS, need for blood products, and more discharge to acute care facilities. This registry study cannot assess reasons for unavoidable delay, such as medical optimization and team or implant availability. LEVEL OF EVIDENCE: III.