Postoperative Morbidity and Discharge Destinations After Fast-Track Hip and Knee Arthroplasty in Patients Older Than 85 Years
Authors: Pitter Frederik T. , Jørgensen Christoffer C. , Lindberg-Larsen Martin , Kehlet Henrik 
Published: May 2016

BACKGROUND:
Elderly patients are at risk of increased length of hospital stay (LOS), postoperative complications, readmission, and discharge to destinations other than home after elective total hip arthroplasty (THA) and total knee arthroplasty (TKA). Recent studies have found that enhanced recovery protocols or fast-track surgery can be safe for elderly patients undergoing these procedures and may result in reduced LOS. However, detailed studies on preoperative comorbidity and differentiation between medical and surgical postoperative morbidity in elderly patients are scarce. The aim of this study was to provide detailed information on postoperative morbidity resulting in LOS >4 days or readmissions <90 days after fast-track THA and TKA in patients ≥85 years.

METHODS:
This is a descriptive, observational study in consecutive unselected patients ≥85 years undergoing fast-track THA/TKA. The primary outcome was the causes of postoperative morbidity leading to an LOS of >4 days. Secondary outcomes were 90-day surgically related readmissions, discharge destination, 90-day mortality, and role of disposing factors for LOS >4 days and 90-day readmissions. Data on preoperative characteristics were prospectively gathered using patient-reported questionnaires. Data on all admissions were collected using the Danish National Health Registry, ensuring complete follow-up. Any cases of LOS >4 days or readmissions were investigated through review of discharge forms or medical records. Backward stepwise logistic regression was used for analysis of association between disposing factors and LOS >4 days and 90-day readmission.

RESULTS:
Of 13,775 procedures, 549 were performed in 522 patients ≥85 years. Median age was 87 years (interquartile range, 85–88) and median LOS of 3 days (interquartile range, 2–5). In 27.3% procedures, LOS was >4 days, with 82.7% due to medical causes, most often related to anemia requiring blood transfusion and mobilization issues. Use of walking aids was associated with LOS >4 days (odds ratio [OR], 1.99; 95% confidence interval [CI], 1.26–3.15; P = 0.003), whereas preoperative anemia showed borderline significance (OR, 1.52; 95% CI, 0.99–2.32; P = 0.057). Thirty-eight patients (6.9%) were not discharged directly home, of which 68.4% had LOS >4 days. Readmission rates were 14.2% and 17.9% within 30 and 90 days, respectively, and 75.5% of readmissions within 90 days were medical, mainly due to falls and suspected but disproved venous thromboembolic events. Preoperative anemia was associated with increased (OR, 1.81; 95% CI, 1.13–2.91; P = 0.014) and living alone with decreased (OR, 0.50; 95% CI, 0.31–0.80; P = 0.004) risk of 90-day readmissions. Ninety-day mortality was 2.0%, with 1.0% occurring during primary admission.

CONCLUSIONS:
Fast-track THA and TKA with an LOS of median 3 days and discharge to home are feasible in most patients ≥85 years. However, further attention to pre- and postoperative anemia and the pathogenesis of medical complications is needed to improve postoperative outcomes and reduce readmissions.