Absence of combined effects of anemia and bilateral surgical status on inpatient rehabilitation outcomes following total knee arthroplasty.

To examine the effects of anemia on inpatient rehabilitation outcomes following unilateral and bilateral total knee arthroplasty (TKA). This was a multicenter, retrospective study from 15 inpatient rehabilitation facilities. Patients (N = 5421) with very low hematocrit (Hct <30%), low Hct (30-36% women, 30-41% men), or normal Hct (>36% women, 41% men) were included. Inpatient rehabilitation occurred following TKA. Functional independence measure (FIM) scores, length of stay (LOS), itemized hospital charges, discharge destination were main outcomes. LOS was 13% longer and hospital charges were 12.5-18.0% higher in the very low Hct than remaining groups (p = 0.0001). The FIM score and subscores for walking, stair climbing, bathing, transfers, and dressing changes were comparable for all Hct groups for the overall score. Hct <30% did not correspond to worse outcomes in patients with bilateral surgeries compared with unilateral surgeries; total FIM scores improved 47-53% across all Hct groups, regardless of bilateral surgical status. Discharge to home ranged 92.6-94.7% across all Hct groups (p > 0.05). Rehabilitation teams can expect comparable functional improvements and discharge to home in anemic and non-anemic patients with either unilateral or bilateral surgeries without hematologic correction in the rehabilitation setting, but might need an additional day to accomplish these outcomes.