Background: As the demand for knee arthroplasty increases, risk assessment and counseling are critical for optimal patient outcomes perioperatively. The purpose of this study was to determine if specific complications occurring after unilateral knee replacement predict the risk of recurrence after a staged replacement of the contralateral knee for patients with bilateral symptomatic disease.
Methods: Linked, nationwide data from the U.S. Hospital Cost and Utilization Project from 2005 to 2014 were used to measure the occurrence of complications after the first and second procedures in staged bilateral total knee arthroplasties (TKAs). Odds ratios (ORs) and conditional probabilities were determined to assess whether having a specific complication after the first TKA increased the chance that the same complication occurred after the second procedure.
Results: A total of 36,278 patients who underwent staged bilateral TKAs were analyzed. All complications occurring after the first arthroplasty were associated with both a significantly increased probability and odds of recurrence following the second arthroplasty. These included myocardial infarction (OR, 56.63 [95% confidence interval (CI), 18.04 to 155.44]; p < 0.001), ischemic stroke (OR, 41.38 [95% CI, 1.98 to 275.82]; p = 0.03), other cardiac complications (OR, 7.73 [95% CI, 4.24 to 14.11]; p < 0.001), respiratory complications (OR, 8.58 [95% CI, 2.85 to 23.17]; p = 0.002), urinary complications (OR, 11.19 [95% CI, 5.44 to 22.25]; p = 0.001), hematoma (OR, 15.05 [95% CI, 7.90 to 27.27]; p < 0.001), deep vein thrombosis (OR, 7.40 [95% CI, 5.37 to 10.08]; p < 0.001), and pulmonary embolism (OR, 11.00 [95% CI, 5.01 to 23.92]; p < 0.001).
Conclusions: Medical complications that occur postoperatively after TKA are associated with a significantly increased risk of recurrence of these complications after staged replacement of the contralateral knee. Although overall complication rates remain low, patients who develop these medical complications after the first replacement should be counseled on their increased risk profile prior to the contralateral surgical procedure.
Level of evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.