After many years of working with hospitals across Europe on Rapid Recovery and outpatient arthroplasty programmes, we have observed something that no protocol document fully captures: the single greatest predictor of a hospital's same-day discharge rate is not its anaesthetic protocol, its patient selection criteria, or even its surgical technique. It is the underlying mindset of the pathway.

In hospitals where outpatient TKA is thriving, the implicit question is: "Which of today's patients has a reason to stay overnight?" In hospitals where it is struggling, the question is: "Which of today's patients might be able to go home?" That difference in assumption produces different outcomes.

Insights from Centres Across Europe

Denmark remains the clearest example. Across the country's fast-track arthroplasty programme, median length of stay fell from 10–11 days in 2000 to just one day by the mid-2010s. A later nationwide registry study covering 166,833 procedures confirmed the continued rise of day-case arthroplasty without an increase in 90-day readmissions. This is not just a story of better protocols, but of a system organised around earlier discharge.

Why Mindset Matters

One of the most important observations from European programmes is the so-called day-case effect. When a hospital introduces a same-day discharge pathway, length of stay falls not only for day-case patients, but across the wider arthroplasty service. In other words, once the default expectation changes, the whole pathway becomes more focused and efficient.

In practice, the difference between a stay-first and a home-first model is simple: