Silkeborg Knee Replacement Cohort Study

All patients follow the same fast-track program including same day surgery for elective knee replacement surgery at the Silkeborg Regional Hospital in Denmark, which includes detailed preoperative written information, multidisciplinary education course for patients and relatives, optimized multimodal pain treatment and early postoperative rehabilitation. Before the admission for surgery, patients will be asked to fulfill several questionnaires and baseline information regarding work situation, educational level and previous treatments. At two weeks there, there is a scheduled follow up by a physical therapist and a nurse at the hospital. At three months there is a scheduled follow up by telephone with a physical therapist.

The study will adhere methodologically to the STROBE guidelines and checklist for prospective cohort studies (www.strobe-statement.org).

Further description is provided elsewhere as eligibility criteria and outcome measures.

Addition to the description:

In January 2019 we started collecting 1 year follow-up data and included questions regarding treatment success, satisfaction and willingness to repeat the surgery.

In March 2019 we decided to make a change in the baseline collection of relevant predictors for primary outcome. The reason for the change was to be able to answer more relevant scientific questions in the cohort study. We replaced "The General Self-efficacy Scale" with "Pain Catastrophizing Scale" and excluded "The General Self-efficacy Scale" from the 12 weeks follow-up collection of outcome measures.

March 2020:

The SIKS study was planned to continue recruitment until reaching minimum 1,000 TKA patients with follow-up data which was deemed sufficient for the purpose of the planned studies. In March 2020, the COVID-19 pandemic closed down all elective orthopaedic surgeries. Because of that, we decided to stop the recruitment to the cohort study with the last patient included (at March 16th, 2020, prior to the COVID-19 lockdown).

December 2020:

The first substudies are planned using data from the SIKS cohort:

1. Predictors of knee pain and functional outcome following Total Knee Arthroplasty - a prospective cohort study with 12 months follow up

   Primary outcome:

   Oxford Knee Score at 12 months

2. Is it feasible and safe to discharge patients on the day of surgery after a total knee arthroplasty?

   Primary outcomes Feasibility measured as length of stay Safety measures as readmission (phone calls, outpatient visits and inpatient visits) and the related reason

   Secondary outcomes Oxfort knee score (90 days) Pain intensity (90 days)

3. Associations between preoperative BMI and postoperative physical activity level and functional capacity 12 months after UKA or TKA surgery.

Primary outcome UCLA scale (12 months)

Secondary outcomes Oxford Knee Score (12 months)