Preoperative anemia and complications after total joint arthroplasty: a systematic review and meta-analysis

The purpose of this review was to collect data from the literature to assess the impact of preoperative anemia on complications after total joint arthroplasty (TJA).

We conducted a literature search on the websites of PubMed, Scopus, CENTRAL, Embase, and Google Scholar for comparative TJA studies reporting complication rates based on the presence of anemia. The last search was conducted on the 15th of May 2022. Studies only on hip and knee replacements were eligible for inclusion.

Twelve studies with 1,463,813 patients published between 2012-2022 were included. Meta-analysis indicated that anemic patients had increased risk of mortality (OR: 2.85 95% CI: 1.89, 2.48 I2=83% p<0.00001), wound complications (OR: 2.06 95% CI: 3.51, 2.48 I2=99% p=0.008), cardiac complications (OR: 2.40 95% CI: 1.56, 3.68 I2=98% p<0.0001), respiratory complications (OR: 2.46 95% CI: 1.10, 5.50 I2=100% p=0.03), renal complications (OR: 2.84 95% CI: 1.39, 5.80 I2=99% p=0.004), sepsis (OR: 3.93 95% CI: 1.15, 13.45 I2=99% p=0.03), urinary complications (OR: 2.42 95% CI: 1.27, 4.59 I2=100% p=0.007), and readmission rates (OR: 1.58 95% CI: 1.42, 1.76 I2=66% p<0.00001) as compared to non-anemic patients undergoing TJA. Most results did not change on sensitivity analysis. There were some non-significant results on subgroup analysis based on joint type and definition of anemia.

Our review suggests that preoperative anemia leads to increased morbidity and mortality after TJA. Specifically, anemia increases the risk of wound, cardiac, respiratory, renal, and urinary complications along with a higher incidence of sepsis and readmissions. Results should be interpreted with caution due to the high heterogeneity in the meta-analyses.