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

Abstract

Purpose: To examine the effects of anemia on inpatient rehabilitation outcomes following unilateral and bilateral total knee arthroplasty (TKA).

Method: 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.

Results: 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).

Conclusions: 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.