Osteoarthritis (OA) is a leading cause of disability and reduced quality of life,
presenting a substantial, growing burden to patients and the healthcare system (1). Total
knee arthroplasty (TKA) is an established, effective interventions for advanced OA. The
prevalence of knee OA is rapidly increasing, resulting in a rising demand for care. The
number of procedures is expected to grow by 48%, by 2020 in the US (2). Currently, TKA
along with total hip arthroplasty (THA), have a significant impact on healthcare budgets,
costing approximately $1.2 billion in annual spending in Canada (3). These staggering
numbers highlight the critical need to improve care delivery.
A significant proportion of the overall cost of joint replacement results from the
inpatient hospital stay following the procedure. Historically, the standard procedure
following TKA required an inpatient hospital stay of two and a half to three weeks,
however the introduction of less invasive surgical techniques, improved medical and
analgesia management and comprehensive rehabilitation have enabled shorter inpatient
stays. Today, the median inpatient stay following TKA is three days in Canada (3). A
desire for greater autonomy by the patients as well as patients wanting early
mobilization to accelerate recovery and return to activities has led some clinicians to
consider an outpatient arthroplasty program. The proposed benefits of outpatient
arthroplasty include similar patient outcomes with significantly lower hospital costs,
and improved patient satisfaction, independence, and autonomy, however there is a lack of
high-quality evidence comparing clinical outcomes of outpatient to inpatient arthroplasty
models of care.
A retrospective analysis of over 50,000 THA and TKA procedures found no differences in
30-day major complications or readmissions among patients with a zero to two-day hospital
stay compared to those discharged on day three or four postoperative (4). Small cohort
studies (5-8) suggest lower costs for outpatients and improved patient satisfaction but
have inherent biases; limited to carefully selected patients in privatized health
systems.
It is estimated that up to 20% of the overall cost of joint replacement can be attributed
to the inpatient stay in hospital at our institution (9). By discharging patients as
outpatients, it could be possible to save 20% of the overall costs of joint replacement.
Although these preliminary calculations are encouraging, it is not sufficient to effect
change solely to achieve cost control, without consideration of safety, effectiveness and
patient satisfaction. Further, it is unknown whether the financial savings will be
outweighed by additional postoperative costs, increased readmissions or decreased quality
of care. A full economic evaluation that simultaneously evaluates cost and effectiveness
is crucial prior to implementation. The lack of high-quality evidence regarding its
effectiveness warrants a rigorous comparative trial.
The purpose of this study is to evaluate outpatient care pathways for TKA. Specifically,
our objectives are to compare the rate of serious adverse events and estimate the
cost-effectiveness of outpatient compared to standard inpatient TKA.