Surgical site infections and other postoperative complications following prophylactic anticoagulation in total joint arthroplasty.
BACKGROUND
Anticoagulants reduce the risk of venous thromboembolism (VTE) after total joint replacement. However, concern remains that pharmacologic VTE prophylaxis can lead to bleeding, which may impact on postoperative complications such as infections and reoperations.


RESULTS
From the Global Orthopedic Registry (GLORY), we reviewed 3,755 patients in US who elected for primary total hip or knee arthroplasty, received either warfarin or low molecular weight heparin (LMWH) as VTE prophylactics, and had up-to-90-day follow-up after discharge. We compared incidence rates of VTE, infections and other complications between LMWH and warfarin groups, and used multivariate analyses with propensity score weighting to generate the odds ratio (OR). Patients receiving LMWH tended to be older and higher in the American Society of Anesthesiologists grade scores. In contrast, warfarin was used more frequently for hip arthroplasty with longer duration among patients with more pre-existing comorbidity (all P<0.02). A weight variable was created with propensity score to account for differences in covariate distributions. Propensity score-weighted analyses showed no differences in VTE complications. However, compared to warfarin, LMWH was associated with significantly higher rates of bleeding (6.2% vs. 2.1%; OR = 3.82, 95% confidence interval [CI], 2.64 to 5.52), blood transfusion (29.4% vs. 22.0%; OR = 1.75, 95% CI, 1.51 to 2.04), reoperations (2.4% vs. 1.3%; OR = 1.77, 95% CI, 1.07 to 2.93) and infections (1.6% vs. 0.6%; OR = 2.79, 95% CI, 1.42 to 5.45). Similar results were obtained from compliant uses of warfarin (26%) and LMWH (62%) according to clinical guidelines. While surgical site infections were mostly superficial, current study was underpowered to compare incidence rates of deep infections (<1.0%).


CONCLUSIONS
Surgical site infections and reoperations in 3 months following primary total joint arthroplasty may be associated with anticoagulant use that exhibited higher bleeding risk. Long-term complications and deep wound infections remain to be studied.
Clinical Trials and Outcomes Branch, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland.
Zhong
Z
Wang
Center for Outcomes Research, University of Massachusetts Medical School, Worcester, Massachusetts.
Frederick A
FA
Anderson
Clinical Trials and Outcomes Branch, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland.
Michael
M
Ward
Clinical Trials and Outcomes Branch, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland.
Timothy
T
Bhattacharyya
D000293:Adolescent; D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use*; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D015331:Cohort Studies; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000209:etiology*; D012042:Registries; D013530:Surgical Wound Infection / Q000209:etiology*; D016896:Treatment Outcome; D014481:United States; D055815:Young Adult
D000925:Anticoagulants