Relationship Between ABO/Rh Blood Groups and Knee Osteoarthritis: A Retrospective Cohort Study

: In this large single-center cohort of patients undergoing primary TKA for primary knee OA, the ABO and Rh(D) blood group distributions were largely comparable to those of the regional population. Although the overall 8-category ABO/Rh(D) comparison showed a borderline difference, separate ABO-only and Rh(D)-only analyses were not significant. These findings do not support a strong association between blood group status and surgically treated primary knee OA in this population.