True "outpatient discharge" following single-stage bilateral unicompartmental knee arthroplasty may be unrealistic for most.

BACKGROUND

Single-stage bilateral unicompartmental knee arthroplasty (BUKA) has shown post-operative function and cost benefits over staged bilateral procedures, without increased complications. A rapid discharge protocol at the current study site has reported outpatient discharge for the unilateral procedure exceeding 97%. However, the feasibility of outpatient discharge following BUKA remains unclear. Therefore, the purpose of this study was to determine the success of achieving outpatient (< 24 h) discharge following BUKA, and identify patient variables associated with failure.

METHODS

A retrospective chart review was completed for 104 BUKA patients. All patients with bilateral, symptomatic unicompartmental knee arthritis were offered the single-stage procedure. Data collection included patient demographics, discharge status, and disposition location. Independent t tests (continuous) and Chi-squared tests (categorical) determined differences between discharge (outpatient/inpatient) and disposition (home/other) groups. Variables associated with discharge status and location were assessed with multivariable regression.

RESULTS

While 96 (92.3%) patients discharged within 24 h, only 63.5% were able to discharge directly home. Patients requiring a longer hospital stay (> 24 h) were more likely to require a pre-operative assistive device (62.5% and 25.0%, p = 0.037) and live alone (37.5 vs 8.3%, p = 0.033). For those discharged within 24 h, living alone significantly increased the risk (odds ratio: 5.800, p = 0.038) of requiring an acute inpatient facility prior to transition home.

CONCLUSION

Achieving "true" outpatient discharge is only modestly successful for most BUKA patients, as many required an acute inpatient or short-term rehabilitation facility prior to returning home. BUKA should be differentiated from the unilateral procedure regarding outpatient discharge expectations.

LEVEL OF EVIDENCE

III, Case-control study; Retrospective comparative study.