Pereira L.C.1, Gkagkalis G.1, Luthi F.1, Lécureux E.1, Jolles B.M.1
1University Hospital of Lausanne, Lausanne, Switzerland
Background: Reducing costs for primary total knee arthroplasty (TKA) remains challenging. These costs are fundamentally driven by major factors such as length of stay (LOS) in hospital, and rehabilitation approach.
Purpose: Various tools have been created to assist clinicians with the task of determining discharge timing and destination, including the Cumulated Ambulation Score (CAS) and the Risk Assessment and Prediction Tool (RAPT). The research questions were: 1. Are the CAS and RAPT useful in predicting the discharge destination of patients undergoing elective TKA? 2. Are the CAS and RAPT useful in estimating hospital length of stay (LOS) following elective TKA?
Methods: This prospective cohort study was conducted in a university hospital setting. (Level I Prognostic Study). Consecutive patients undergoing elective primary TKA were prospectively evaluated. Outcome measures were discharge destination and LOS dichotomized at the median (LOS 8 versus LOS≥8, LOS8). Patients preoperatively completed the EuroQol five-dimensions questionnaire, visual analogue scale for pain, Western Ontario and McMaster Universities Osteoarthritis Index, Knee Society score, and University of California Los Angeles score (UCLA). Knee range of motion was measured preoperatively. The RAPT was considered continuous, and was dichotomized (RAPT≤9 versus RAPT>9, RAPT9. The CAS was dichotomized (CAS 11 versus CAS≥11, CAS11). Surgical technique and aftercare were identical for all patients.
Results: Sixty-four patients (37 females), mean age 69.3±10.2 years and mean body mass index 30.14±6.02, were evaluated. CAS11 and discharge destination were strongly associated: 75.9% of patients with CAS≥11 were discharged home; 85.7% of patients with CAS 11 were discharged to a rehabilitation centre (P 0.001). Logistic regression analysis indicated a CAS11 OR of 18.9 (95% CI 1.3-22.8) for discharge home. 80.7% of patients with RAPT≤9 were discharged to a rehabilitation center, versus 36.4% of patients with RAPT>9 (p=0.002). Logistic regression analysis indicated a RAPT OR of 7.3 (95% CI 1.3-22.8) for discharge home. The CAS11 and RAPT were not related to LOS. The discriminative power between the preoperative variables and LOS was small (VAS pain pseudo R2=0.11).
Conclusion(s): The CAS and RAPT are helpful in estimating the discharge destination following elective primary TKA. However, predicting LOS with such tools alone was inaccurate.
Implications: Preoperatively with the RAPT and at D3 with the CAS, physiotherapists will be able to objectively determine the discharge destination for patients undergoing TKA. This may represent an opportunity for cost reduction through early organisation of discharge. The benefits of using the CAS routinely could be further supported by a thorough socioeconomic analysis highlighting the importance of predicting the discharge destination.
Funding acknowledgements: There was no funding or commercial associations that might pose a conflict of interest in connection with the submitted article.
Topic: Orthopaedics
Ethics approval: Ethical approval was obtained from the local Research Ethics Board (CER VD 144/13).
All authors, affiliations and abstracts have been published as submitted.
