The goal of this clinical trial is to test and learn about Virtual Reality (VR) providing preoperative information to patients undergoing elective TKA surgery in spinal anesthesia. The main question(s) aim(s) to answer if:

• Can preoperative information through a VR headset lower the patients preoperative anxiety?
• Can VR information make the patients more ready for surgery. Painscore will also be collected.

Participants will be randomized into two groups. One that will have preoperative information through VR versus standard information.

If there is a comparison group: Researchers will compare enrolled TKA patients to see if VR have an impact on anxiety, readiness and pain

Knee osteoarthritis (OA) causes pain, disability and poor quality of life in the elderly. Consequently, it can severely affect people's quality of life and physical function. International guidelines recommend exercise therapy alongside patient education and weight management (if needed) as first-line treatment for all individuals with knee OA. However, more than 1,000,000 TKA procedures are performed annually worldwide, and with aging populations and an increase in obesity, this number is expected to increase markedly4. Although TKA is generally considered an effective treatment option, up to 20% of patients are not fully satisfied after surgery5. Spinal anesthesia is commonly used during primary TKA given the purported safety benefits, quicker immediate postoperative recovery, decreased intraoperative bleeding, and lower transfusion rates when compared to general anesthesia. To help the patient feel more comfortable and relaxed during a procedure, administration of sedative medication titrated by the anesthetist is common practice. Despite a low rate of complications associated with spinal anesthesia compared to general anesthesia, it is important to acknowledge that complications can still occur.

Virtual Reality (VR) demonstrates signs as a promising tool to support healthcare, including mentally preparing the patient for a surgical procedure. Preoperative readiness, expectations, anxiety, and pain perception are crucial to the patient's surgical experiences. VR can immerse patients into a virtual environment and distract patients from e.g., unpleasant sounds, sights, and feelings. Integrating VR into preoperative care has shown the potential to offer several advantages, such as promoting patients' distraction, knowledge, and information. However, harms have been reported such as cyber sickness but only in few cases among older adult patients.

Offering a controlled environment where patients can familiarize themselves with the surgical process through VR shown on a head-mounted display (HMD) and with sound reduction headphones provides them an opportunity to explore, e.g., the operation theater, waiting area, and PACU.

All this can foster a sense of confidence and increased readiness and lead to an overall improved patient experience.

Ethical considerations: this trial will assess the effects of using a VR patient journey preoperatively. Therefore, the trial will be highly systematic and at low risk of producing biased results. The trial will be adequately powered to limit the risk of random error. The participants receiving standard of care will likely not benefit directly from the trial. However, the participants in the control group will potentially assist with valuable evidence, which might benefit future patients. Participants can, at any time, for any reason, withdraw their consent to participate in the trial. If participants withdraw from the trial, it will not impact the level of care and treatment offered by the departments.

Informed consent: the trial will be conducted according to national and international standards of Good Clinical Practice. This trial protocol and amendments will be submitted to the Committee on Health Research Ethics in the Region Zealand of Denmark for approval before initiation of the trial. All patients scheduled for total knee arthroplasty will be screened for inclusion. The patients will be provided oral and written information about the trial, including potential benefits and risks, and invited to participate. The oral and written information will enable the patient to decide whether or not to participate in the trial. If the patients match all inclusion criteria and none of the exclusion criteria and decides to participate in the trial, both the patient and one of the trial personnel will have to sign the written informed consent paper.

The oral and written information can be provided by the Ph.D. student, a project nurse, or any employee from the project, collectively known as "trial personnel." The trial personnel can obtain consent. The trial personnel will be trained in all the procedures related to screening, informing potential participants, obtaining informed consent and inclusion of participants, randomization of participants, and how to handle the VR equipment.

Patients scheduled for elective surgery will be informed about the conduct of the trial at the anesthesia or orthopedic pre-consult, and written trial information will be provided.

All patients considered for inclusion will be informed about the mandatory verbal trial information consult. The patients will be informed of the possibility of bringing a next of kin to the mandatory verbal trial information consult. The verbal trial information consult will be held by other personnel trained to do so according to the Good Clinical Practice guidelines. The consult will take place in an explicit reserved room to prevent any disruptions. . The patient will be informed of the possibility of considering participation in the trial. The verbal trial information consult will be based on written information and contain information on the trial's purpose, potential risks and benefits, and the conduct of the trial. We will ensure that all patients, irrespective of being scheduled for surgery, will have at least 24 hours to consider their participation in the trial.

The patient will be informed that participation in the trial is voluntary and that consent can be withdrawn at any time without the decision to withdraw impacting further treatment. The patient will be asked if the investigators may continue to collect data relevant to the trial from the patient's medical records and if we are allowed to call them postoperatively to schedule an interview. Patients will be informed that randomization takes place on the day when the pre-anesthetic meeting is taking place. All stakeholders are bound by secrecy. The patient will receive trial information and the written informed consent declaration.

Inclusion Criteria:

• Scheduled for total knee arthroplasty
• Scheduled for spinal anesthesia
• Age of 18 or above
• Ability to understand the trial protocol, risks, and benefits and provide signed informed consent

Exclusion Criteria:

• Inability to read and understand Danish
• Uncooperativeness (as judged by investigators)
• Claustrophobia or fear of small spaces
• Disorders that prevent the person from wearing a VR device
• Highly visually or auditive impaired

The primary investigator will stay blinded in this study and an assistant to the investigator is screening and including the patients and collecting data.