Background: Serum d-dimer is a common screening test for symptomatic deep venous thrombosis (DVT) after total joint arthroplasty. This study characterized the longitudinal resolution of d-dimer measurements after total hip and knee arthroplasty (THA/TKA) over a 6-week period. The authors hypothesized that serum d-dimer would not return to baseline or be below the institutional threshold for a positive test at 6 weeks after uncomplicated total joint arthroplasty, suggesting that quantitative d-dimer has limited clinical utility for postoperative DVT screening.
Methods: An institutional review board-approved retrospective cohort study was conducted with consecutive patients between January 2013 and June 2015. A total of 177 adult patients aged 40-88 years who underwent a primary hip or knee arthroplasty with a Charlson Comorbidity Index <3 were included in the study. Serum d-dimer was measured at preoperative, perioperative, and postoperative 2- and 6-week time points.
Results: d-dimer measurements peaked 2 weeks postoperatively for both TKA and THA. At the 6-week time point, the peak serum d-dimer measurement resolved by 54.3% and 76.6% for TKA and THA, respectively. At 6 weeks after operation, 92% of THA patient and 100% of TKA patients had serum d-dimer measurements higher than the institutional threshold (0.40 μg/mL) for a "positive" quantitative test. No symptomatic DVTs were reported for the THA and TKA cohorts during the study period.
Conclusion: The results suggest that serum d-dimer is an ineffective screening test for the diagnosis of symptomatic DVT in the acute postoperative period. The authors propose that extravascular fibrinolysis, a process essential for wound healing, has a crucial role in the prolonged elevation of serum d-dimer in the postoperative period.
Keywords: d-dimer; deep vein thrombosis; hip; knee; total joint arthroplasty; ultrasound.
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