Patient Frailty in Total Knee Arthroplasty: The Implementation of a Frailty Score Using an Electronic Medical Record.

Background: Frailty has been associated with poor outcomes and higher costs after primary total knee arthroplasty (TKA). However, the implementation of a frailty score at a level one tertiary care facility to evaluate patient outcomes has not been well described. This study examined the retrospective implementation of the Hospital Frailty Risk Score (HFRS) and the relationship of the HFRS score with 90-day readmission, revision at any time point, and length of initial hospitalization.

Methods: Using our relational database from our hospitals' electronic medical record system, we identified patients who were discharged following primary TKA from 2015 to 2023. The HFRS was calculated for each patient to determine frailty. Frail patients were defined as those who had an HFRS ≥ 5 and nonfrail patients had an HFRS < 5. We used regression analyses to adjust for demographic confounders to evaluate the association of patient frailty (as defined by an HFRS ≥ 5) following primary TKA and patient outcomes, including 90-day readmissions, revision TKA, and length of hospital stay.

Results: Frail patients had significantly higher rates of 90-day readmission (79 versus 14), revision (30 versus 11), and length of initial hospitalization (3.5 ± 3.5 versus 2.8 ± 2.3 days) (P < 0.0001). Frail patients were at increased risk of revision TKA for mechanical loosening (0.35 versus 0.045%, P < 0.05). Also, frail patients were at significantly higher risk for readmission and revision for infection compared to the nonfrail cohort (1.4 versus 0.17%, P < 0.0001; 0.81 versus 0.25%, P < 0.05).

Conclusions: Frailty, measured using HFRS, is associated with increased 90-day readmission, revision, and inpatient length of stay following primary TKA. Frail patients are at significantly increased risk of infectious complications following primary TKA. This study demonstrates that the HFRS can be implemented using a common electronic medical record and may help multidisciplinary care teams better focus preoperative optimization interventions on this high-risk cohort.