The fast track group vs. control group will be compared with regard to hospitalization time and the non-inferiority of the fast track group vs. control group with regard to HOOS will be assessed.

The questionnaires will only be collected in the study: Eq-5d-5l, HOOS, self-efficacy, enjoyment of movement, fear of movement, pain catastrophizing.

Around 400,000 hip and knee endoprostheses are implanted in Germany every year. Due to demographic change, the trend is clearly on the rise, which also results in rising costs in this area for the solidarity community. The Clinic for Orthopaedics and Sports Orthopaedics at the TUM Clinic is about to implement the Fast Track method after total hip arthroplasty (THA, in German: Hüft-TEP). The aim of this method is to shorten the length of stay in hospital and the post-operative recovery time as well as to promote rapid mobilization and independence of patients without worsening the functional outcome or the complication rate. The investigators will therefore investigate the extent to which it is possible to reduce the length of hospital stay without compromising function.

• Primary endpoints: Hospital length of stay, HOOS.
• Secondary endpoints: PROMs Quality of life Eq-5d-5l (EuroQol 5 dimensions Lang) Function Mobility (TUG test) in seconds Pain (NRS), ROM (neutral zero method), Strength (Nm/kg body weight, muscle function test) Self-efficacy/ pleasure/ fear of movement/pain catastrophizing Exercise self efficacy scale (ESES), physical activity enjoyment scale (PACES), Kinesiophobia (TSK), Pain catastrophizing scale (PCS).

With an original length of stay of 6 days and a target length of stay of 4 days, the expected reduction is 2 days. A standard deviation of 3 days is assumed in both groups (calculations based on patient data from August to December 2024) and a significance level of 0.05 and power of 80% are assumed. The required number of cases is therefore at least 36 participants per group. With this number of cases, the non-inferiority of the fast-track method compared to the standard method with regard to HOOS can also be demonstrated with a probability of 80%, assuming that the true mean difference between the methods is 0 points and the standard deviation for both methods is 15 points (Δ = 10 points, one-sided 97.5% confidence interval). To compensate for a potential drop-out rate, 45 patients per group should be recruited. With a primary hip TEP (THA) surgery rate of approx. 10 patients per week (cf. 2024) and a 2-month duration per group, the investigators can recruit a maximum of 80 patients per group. The investigators are therefore confident that the required case number of 45 per group will be reached.

Inclusion Criteria:

• Age ≥18 years
• The patient will undergo surgery at Klinikum rechts der Isar, Technical University of Munich (TUM)
• Written informed consent for participation in the study after detailed explanation of the nature, significance, risks and scope of the clinical trial
• Written informed consent from the patient for data collection and data processing, with the patient fully informed.
• Sufficient German language skills of the patient.

Exclusion Criteria:

• Age < 18 years
• The patient is under guardianship, legally incapacitated or has limited legal capacity
• Only partial weight-bearing permitted

Hip arthroplasty elective