Preoperative Anemia Is Associated With Worse Joint-Specific Postoperative Outcomes, but Is Not Associated With Health-Related Quality of Life or Patient Satisfaction After Total Knee Arthroplasty.

BACKGROUND

The primary aim assessed whether preoperative anemia was associated with a worse knee-specific functional outcome after total knee arthroplasty (TKA). The secondary aims assessed the association of preoperative anemia with generic health and patient satisfaction.

METHODS

A retrospective cohort study was undertaken to compare patients who did and did not have anemia (Hb <13.0 g/dL for men and Hb <11.5 g/dL for women). During a 1-year period, 497 patients underwent a total knee arthroplasty with complete preoperative and postoperative data, including 215 (43.3%) men and 282 (56.7%) women, who had a mean age of 70 years (range 45-93). Patient demographics, comorbidities, preoperative and postoperative (1 year) Oxford Knee Score (OKS), EuroQol 5 dimension (EQ-5D), postoperative Forgotten Joint Score (FJS), and patient satisfaction were collected. Regression analyses were used to adjust for confounding factors between the groups.

RESULTS

The 56 (11.3%) patients who had anemia were older (4.6 years, P < .001) and more likely to have chronic obstructive pulmonary disease (P = .004), connective tissue (P = .047), or kidney disease (P = .011) compared to those who did not have anemia. There were no differences in the preoperative OKS (P = .752) or EQ-5D (P = .762) scores between the groups. When adjusting for confounding differences, there was a significantly lower postoperative OKS (-3.0 points, P = .035) and FJS (-11.6 points, P = .011) associated with the anemia group. There were no significant differences in the EQ-5D (P = .118) or patient satisfaction between groups (odds ratio 0.84, P = .976).

CONCLUSION

Preoperative anemia is associated with a lower postoperative joint-specific functional outcome. It is not clear if these differences are clinically meaningful. No difference in patient satisfaction was observed.

LEVEL OF EVIDENCE

Level III, diagnostic study.