Predictors of Facility Discharge, Range of Motion, and Patient-Reported Physical Function Improvement After Primary Total Knee Arthroplasty: A Prospective Cohort Analysis

Abstract Background Patients are discharged to home or inpatient settings after primary unilateral total knee arthroplasty (TKA). Few studies have compared patient outcomes following these 2 rehabilitation models for TKA patients. We identified predictors of inpatient discharge, 3-month postoperative range of motion (ROM), and 3-month postoperative patient-reported physical function improvement (Veterans RAND 12-Item Physical Component Score [PCS]) between these discharge settings. Methods We studied prospectively collected cohort data for 738 TKAs between April 2011 and April 2013 at a high-volume tertiary academic medical center in a rural setting. All patients followed a standardized care pathway that involved prospective data collection as part of routine clinical care. Adjusting variables included age, sex, preoperative PCS, surgeon, modified Charlson Comorbidity Index, preoperative body mass index, laterality, and preoperative ROM; the 3-month models also included length of stay and discharge disposition as adjusters. Results Significant adjusted predictors of inpatient discharge included older age, female sex, surgeon, comorbidity, lower PCS, and body mass index greater than 40. Only lower preoperative ROM predicted postoperative ROM. Inpatient discharge and higher preoperative PCS predicted lower PCS improvement. Home-based rehabilitation was associated with greater 3-month PCS improvement and showed no difference with 3-month ROM. Conclusion Discharge to home-based rehabilitation after TKA, rather than inpatient facility, is associated with higher physical function at 3 months postsurgery and shows no difference with 3-month ROM. Total knee arthroplasty inpatient discharge should be based on patient care requirements rather than perceived benefit of improved ROM and physical function.