Knee OsteoarthritisKNEE-CYCLENCT07838012
Feasibility of an Early Home-based Cycling Intervention After Knee Arthroplasty
A study testing Early home-based stationary cycling in people with Knee Osteoarthritis and Knee Arthroplasty, run by Central Jutland Regional Hospital at 1 site in Denmark.
Trial summary
The goal of this pilot clinical trial is to evaluate whether an early, home-based stationary cycling programme, provided in addition to standard postoperative home exercises, is feasible and acceptable for patients recovering from knee arthroplasty. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Knee Osteoarthritis, Knee Arthroplasty
- What is being tested?
- Early home-based stationary cycling
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteDenmark
- Study dates
- 21 Sep 2026to Mar 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Scheduled for unilateral primary medial unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA).
- Age ≥ 18 years.
- Able to speak and read Danish.
- Daily access to a stationary bike during the intervention period, or willingness to use a stationary bike provided by the study through an external rental company for the duration of the intervention. Due to logistical constraints, loan bikes can only be provided to participants residing within approximately one hour of transport from Aarhus or Silkeborg. Participants living outside this area may participate if they have access to a stationary bike.
- Ability to use a smartphone with internet connectivity (required for completion of electronic questionnaires and using SENS motion application) or a tablet and having an email address enabling completion of electronic questionnaires.
Who cannot join
- Previous surgery in either lower limb within 3 months before the date of knee arthroplasty or planned surgery in either lower limb within 3 months after the date of knee arthroplasty.
- Inflammatory joint disease
- Previous osteotomy around the knee or tibial condyle fracture that has been treated with osteosynthesis in the affected knee.
- Medical or physical conditions that would prevent safe participation in the cycling intervention (e.g., unstable cardiovascular, pulmonary, or chronic neurodegenerative disorders).
- Active cancer treatment, if this treatment would interfere with safe participation or adherence to the cycling protocol.
- Preoperative reduced knee flexion preventing full pedal rotation on a stationary bike.
- Current or recent history of alcohol and/or substance misuse, as identified during the anaesthetic pre-assessment and documented in the electronic patient record.
- Cognitive impairment (e.g. dementia) or diagnosed psychiatric disorder that would prevent the patient from understanding or adhering to the cycling protocol.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Denmark1 site, 1 recruiting
- Recruiting
Regional Hospital Silkeborg
Silkeborg, Central Jutland, 8600
Mette Garval, MSc, 0045 29773935, metgar@rm.dk
David H Christiansen, Professor, 0045 2168 8431, David.Christiansen@midt.rm.dk
About this study
Official title: Feasibility of Adding Early Home-based Cycling to Standard Exercises After Knee Arthroplasty: A Pilot Randomised Controlled Trial
The goal of this pilot clinical trial is to evaluate whether an early, home-based stationary cycling programme, provided in addition to standard postoperative home exercises, is feasible and acceptable for patients recovering from knee arthroplasty. It will also inform the design of a larger clinical trial examining the effects of adding early cycling to standard postoperative home exercises on postoperative outcomes.
The main questions it aims to answer are:
Read more
- Can the cycling programme and planned study procedures be delivered as intended?
- Are participants willing and able to take part in the study and follow the planned interventions?
- Do participants find the cycling programme and outcome assessments acceptable?
- What changes, if any, are needed before conducting a larger clinical trial?
Researchers will compare an early home-based stationary cycling programme provided in addition to standard postoperative home exercises with standard postoperative home exercises alone.
Participants will:
- Be randomly assigned to either the cycling group or the standard exercise group (control group) two weeks after surgery.
- If assigned to the cycling group, perform 30 minutes of stationary cycling at home at least five days per week for eight weeks in addition to the standard postoperative home exercise programme.
- If assigned to the control group, follow the standard postoperative home exercise programme and refrain from structured cycling during the eight-week intervention period.
- Complete questionnaires and physical assessments at baseline and follow-up visits.
- Complete selected patient-reported outcome measures at 6 and 12 months after surgery.
Read the detailed description
This pilot randomised clinical trial will evaluate the feasibility, acceptability, and safety of an early, home-based stationary cycling intervention added to standard postoperative home exercises following knee arthroplasty. The study will also evaluate the feasibility of the study procedures required for a subsequent full-scale randomised clinical trial.
A total of 24 participants will be randomised in a 1:1 ratio to either the cycling intervention group or the control group. Both groups will receive the standard postoperative home exercise programme. Participants allocated to the cycling intervention group will additionally perform the structured home-based cycling programme for eight weeks. Participants allocated to the control group will follow the standard postoperative home exercise programme without structured cycling during the intervention period. Outcome assessors conducting the 10-week follow-up assessments will be blinded to group allocation.
The pilot will address several aspects of feasibility, including screening and recruitment, retention and completion of follow-up, adherence to the allocated study intervention, acceptability of the cycling intervention, safety, and the practicality and burden of study procedures. In the control group, adherence to the instruction to refrain from cycling during the intervention period will also be assessed. The study will additionally examine the practical and logistical feasibility of delivering the cycling intervention at home, including access to stationary bikes and, where required, provision of bikes through an external rental service.
Participants will complete selected patient-reported outcome measures preoperatively and undergo a baseline assessment two weeks after surgery, before randomisation. Preoperative assessments are included for measures for which assessment two weeks after surgery is not considered appropriate or informative. Following the baseline assessment and randomisation, participants will receive the allocated intervention. The main follow-up assessment will be conducted at 10 weeks after surgery, following completion of the eight-week cycling intervention.
Recruitment feasibility will be assessed throughout the recruitment period, including screening, eligibility, recruitment rate, and reasons for declining participation. Retention will be assessed by attendance at the 10-week follow-up and completion of planned assessments.
Intervention feasibility will include adherence to the prescribed cycling dose using the SENS Motion® activity tracker, participant-reported symptoms related to cycling, and acceptability of the intervention. In the control group, adherence to the instruction to refrain from cycling will also be assessed. Safety will be assessed by recording and describing adverse events and serious adverse events occurring during the study, including events potentially related to the cycling intervention.
Feasibility of the study procedures will include completion and burden of questionnaires and physical and performance assessments, as well as the duration and practical challenges associated with baseline and follow-up assessments, intervention delivery, equipment, and study visits. The practical and logistical feasibility of providing stationary bikes through an external rental service will also be evaluated. Participant feedback, qualitative interviews, and feedback from project staff and the clinical team will provide additional information on practical aspects of study conduct.
Completion of patient-reported outcome measures will be assessed as a separate feasibility aspect. Overall completion, completion of individual questionnaires, and missing questionnaire items will be examined to identify measures or items that may be difficult to complete, perceived as less relevant, or contribute substantially to assessment burden. These findings may inform refinement of the outcome assessment battery for the subsequent full-scale trial.
Predefined progression criteria will be used to guide the decision whether to progress to a future full-scale randomised clinical trial. The criteria address recruitment rate, adherence in the intervention and control groups, 10-week follow-up completion, and completion of baseline physical and performance assessments. A traffic-light system will be used to indicate whether progression is feasible as planned, may require modifications or further clarification, or is not recommended in its current form. The progression criteria will be considered together with additional qualitative and practical information collected during the pilot.
The primary feasibility evaluation will take place at 10 weeks after surgery. Clinical and patient-reported outcomes collected during the pilot will be analysed descriptively to provide exploratory information on postoperative recovery, outcome variability, and potential between-group differences. The Knee injury and Osteoarthritis Outcome Score (KOOS) will be assessed using the Pain, Symptoms, Activities of Daily Living (ADL), and Quality of Life subscales preoperatively and at the 10-week follow-up. These four subscales comprise the KOOS4. The proportion of participants achieving a minimally important change in KOOS4 will be explored descriptively.. These data will also contribute to planning the outcome assessment and statistical design of the subsequent full-scale randomised clinical trial.
Selected patient-reported outcome measures will also be collected at 6 and 12 months after surgery. These data will provide exploratory information on longer-term outcomes and the feasibility of longer-term follow-up. The longer-term follow-up will not determine the main feasibility evaluation at 10 weeks.
Overall, the findings from the pilot will be used to determine whether modifications to the intervention, study procedures, recruitment or retention strategies, or outcome assessment battery are required before conducting a subsequent full-scale randomised clinical trial.
- Conditions
- Knee Osteoarthritis, Knee Arthroplasty
- Being tested
- Early home-based stationary cycling, Usual care: home-based exercise programme
- Keywords
- Knee arthroplasty, Postoperative rehabilitation, Home-based rehabilitation, Stationary cycling, Feasibility study, Postoperative recovery
- Medical subject headings
- Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Early home-based stationary cyclingOther
Participants will receive individual instruction in the cycling protocol from a physiotherapist in addition to the standard postoperative home-based exercise programme described for the control group. Beginning two weeks after knee arthroplasty, participants will perform 30 minutes of home-based stationary cycling at least five days per week for eight weeks. Cycling will initially be performed at a comfortable pace with no resistance and a cadence of approximately 50-60 rpm, with cadence and resistance gradually increasing as tolerated. If unable to complete full pedal rotations, participants will perform pendulum exercises twice daily for five minutes until sufficient knee flexion is achieved. A traffic-light symptom guide will be used to adjust cycling according to pain and swelling. Participants will not be routinely referred to supervised rehabilitation during the intervention period but may contact the physiotherapy team for advice or attend a consultation if clinically indicated.
Usual care: home-based exercise programmeOther
Participants will follow the standard post-operative home-based exercise programme, consisting of five exercises targeting knee range of motion and quadriceps strength, performed twice daily. At the two-week post-operative follow-up, participants will receive instruction in a second exercise programme. The exercises prescribed will be individually adjusted by a physiotherapist according to the participant's recovery and readiness for progression, including knee range of motion, functional capacity, and pain. Participants will not be routinely referred to supervised rehabilitation during the intervention period but may contact the physiotherapy team for advice or attend an additional consultation if clinically indicated.
| Study group | Role | What they receive |
|---|---|---|
| Early home-based stationary cycling | Experimental | Participants will begin a home-based stationary cycling programme two weeks after knee arthroplasty. They will perform 30 minutes of stationary cycling at least five days per week for eight weeks, in addition to the standard postoperative home-based exercise programme. Receives: Other: Early home-based stationary cycling |
| Usual care: home-based exercise programme | Active comparator | Participants will follow the standard postoperative home-based exercise programme beginning two weeks after knee arthroplasty. The programme focuses on knee mobility and muscle activation and does not include the stationary cycling intervention. Receives: Other: Usual care: home-based exercise programme |
What is being measured
The primary outcome is the main question the study is designed to answer.
Screening and eligibility rate
The number of patients screened per week and the proportion who are eligible.
Measured: From study initiation until completion of recruitment.
Recruitment rate
Number of eligible patients providing verbal agreement to participate per week and proportion of eligible patients providing verbal agreement to participate.
Measured: From study initiation until completion of recruitment.
Declined participation among eligible patients
Number and proportion of eligible patients who decline participation after receiving study information.
Measured: From study initiation until completion of recruitment.
Baseline assessment completion
Proportion of participants who provide written informed consent and complete the planned baseline assessment before randomisation. Completion of individual objective and physical performance assessments will also be recorded to identify any assessments that are not completed.
Measured: At baseline, before randomisation
Retention and completion of 10-week follow-up assessments
Proportion of randomised participants who attend the 10-week follow-up assessment and proportion who complete all planned objective and physical performance assessments, reported separately for the intervention and control groups. Reasons for non-attendance and incomplete assessments will also be recorded.
Measured: 10 weeks after surgery
Adherence to the cycling intervention
Objective adherence to the prescribed cycling intervention, including frequency and duration of cycling sessions and the proportion of prescribed cycling days completed, assessed using the SENS Motion® sensor system.
Measured: 2 to 10 weeks after surgery.
Cycling-related pain, swelling and discomfort
Participant-reported pain, swelling and discomfort related to cycling, assessed during a structured telephone assessment approximately one week after initiation of the cycling intervention. Responses will be recorded descriptively. Participants unable to complete full pedal rotations will be contacted again one week later.
Measured: Approximately 1-2 weeks after initiation of the cycling intervention.
Acceptability of the cycling intervention
Participant-reported acceptability of the home-based cycling intervention assessed using selected items from the Theoretical Framework of Acceptability (TFA) questionnaire. The items assess affective attitude, burden, perceived effectiveness, self-efficacy, and overall acceptability. Responses are recorded on five-point Likert scales.
Measured: 10 weeks after surgery.
Completion of patient-reported outcome measures
Proportion of participants who complete all planned patient-reported outcome measures (PROMs) at baseline and 10-week follow-up. Completion of individual PROMs and missing questionnaire items will also be recorded to identify PROMs with incomplete data.
Measured: Baseline and 10 weeks after surgery
Participant-reported burden of outcome assessments
Participant-reported burden of the questionnaires and objective assessments, assessed using two yes/no questions on whether the assessments were so burdensome that the participant would choose not to participate in a similar study again. Participants answering "yes" will be asked to provide a brief reason.
Measured: Baseline and 10 weeks after surgery
Adverse events and postoperative complications
Adverse events and postoperative complications reported by participants or identified in electronic health records during the study period. Events will be recorded and summarised descriptively.
Measured: From randomisation to 10 weeks after surgery.
Secondary outcomes (18)
Knee-related pain, symptoms, function and quality of life
Knee-related pain, symptoms, function in activities of daily living, and knee-related quality of life assessed using four subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS): Pain, Symptoms, Activities of Daily Living, and Quality of Life. Each subscale is scored from 0 to 100, with higher scores indicating better outcomes. The KOOS4 is calculated from these four subscales. The individual four KOOS subscale scores will also be reported.
Measured: Pre-operatively, 10 weeks, 6 months, and 12 months after surgery.
Health-related quality of life
Health-related quality of life assessed using the EuroQol 5-Dimension 5-Level questionnaire (EQ-5D-5L). Each of the five dimensions is scored from 1 to 5, with higher scores indicating greater severity of problems. The five dimensions assess mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Self-rated health will also be assessed using the EQ visual analogue scale (EQ VAS), scored from 0 to 100, with higher scores indicating better self-rated health.
Measured: Pre-operatively, 10 weeks, 6 months, and 12 months after surgery.
Mental well-being
Mental well-being assessed using the World Health Organization-Five Well-Being Index (WHO-5). The raw score ranges from 0-25, with higher scores indicating better mental health. The raw score will be transformed to a percentage score from 0-100, with higher scores indicating better mental well-being.
Measured: Pre-operatively, 10 weeks, 6 months, and 12 months after surgery.
Early recovery
Patient-reported early postoperative recovery assessed using the Oxford Arthroplasty Early Recovery Score (OARS). The overall 14-item OARS is scored from 0 to 100, with higher scores indicating better recovery.
Measured: Baseline, 6 and 10 weeks after surgery.
Early change in recovery
Patient-reported change in early postoperative recovery assessed using the Oxford Arthroplasty Early Change Score (OACS). The OACS is scored from -50 to 50, with higher scores indicating greater improvement. A score of 0 indicates no change from preoperative health status.
Measured: Baseline, 6 and 10 weeks after surgery.
Pain intensity
Self-reported knee pain intensity at rest, during activity, and at its worst during the previous 24 hours, assessed using an 11-point Numeric Rating Scale (NRS; 0-10).
Measured: Pre-operatively, at baseline, and at 6 and 10 weeks and 6 and 12 months postoperatively.
Pain distribution
Presence and distribution of pain during the previous week, assessed using a pain mannequin covering predefined body regions. Participants indicate whether pain is present and, where applicable, whether it affects the left side, right side, or both sides.
Measured: Pre-operatively, at 10 weeks and 6 and 12 months after surgery.
Pain medication use
Use of pain medication assessed using categorical patient-reported questions. Participants will report whether they use pain medication (yes/no), whether the medication is taken because of knee pain (no/yes/both knee pain and other pain), and the frequency of use of over-the-counter pain medication and strong opioid pain medication. Frequency of use is categorised as never or rarely, several times per month, several times per week, once daily, or several times daily. Use of strong opioid pain medication is assessed as no, yes, or do not know, followed by the same frequency categories for participants reporting use.
Measured: Pre-operatively, at baseline, and at 6 and 10 weeks and 6 and 12 months after surgery.
Knee range of motion
Knee range of motion assessed using goniometric measurement, reported in degrees (°). Knee flexion and extension range of motion will be measured.
Measured: Baseline and 10 weeks after surgery.
Knee range of motion
Patient-reported knee range of motion assessed using the Copenhagen Knee Range of Motion Scale (CKRS), a pictorial questionnaire in which participants select the image that best represents their knee range of motion. Knee flexion is scored from 0 to 6, with higher scores indicating greater knee flexion, and knee extension is scored from 0 to 5, with higher scores indicating greater knee extension.
Measured: Pre-operatively, 6 weeks, 6 months, and 12 months after surgery.
Knee swelling
Knee swelling assessed by circumference measurements of the operated and non-operated knees.
Measured: Baseline and 10 weeks after surgery.
40-metre fast-paced walk test
Walking performance assessed using the 40-metre fast-paced walk test.
Measured: Baseline and 10 weeks after surgery.
30-second chair stand test
Physical performance assessed using the 30-Second Chair Stand Test, measured as the number of full chair stands completed in 30 seconds. Higher scores indicate better physical performance.
Measured: 10 weeks after surgery.
Stair climb test
Physical performance assessed using the Stair Climb Test, measured as the time in seconds required to ascend a predefined 9 stairs. Lower scores indicate better physical performance.
Measured: 10 weeks after surgery.
Pain sensitivity
Pain sensitivity assessed using quantitative sensory testing (QST) with cuff algometry.
Measured: Baseline and 10 weeks after surgery.
Physical activity level
Physical activity level assessed using the one-item University of California, Los Angeles (UCLA) Activity Scale. The scale ranges from 1 to 10, with higher scores indicating a higher level of physical activity.
Measured: Pre-operatively, and at 10 weeks, 6 months, and 12 months after surgery.
Objective physical activity
Objective physical activity assessed using the SENS Motion® sensor system. Activity data collected during the final week of the 8-week intervention period will be used to assess daily step count and time spent at different activity intensity levels.
Measured: During the final week of the 8-week intervention period.
Patient satisfaction and perceived outcome
Participants' overall assessment of their operated knee, including pain and ability to perform activities of daily living, compared with before surgery, assessed 7-point Global Perceived Effect (GPE) scale scored from 0 to 6, with higher scores indicating a better perceived outcome. At 6 and 12 months after surgery, patient satisfaction and perceived treatment outcome will additionally be assessed using questions addressing satisfaction with the surgical result, willingness to undergo surgery again given the experienced treatment course and outcome, an acceptable current state of knee function, and perceived treatment failure.
Measured: 10 weeks, and 6 and 12 months after surgery.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Sep 2026
- Study start21 Sep 2026
- Primary completionMay 2027 (estimated)
- Study completionMar 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Knee OsteoarthritisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants will be randomly assigned in a 1:1 ratio to one of two parallel groups, with randomisation stratified by type of knee arthroplasty (unicompartmental knee arthroplasty \[UKA\] or total knee arthroplasty \[TKA\]). The cycling intervention group will receive an eight-week home-based stationary cycling programme in addition to standard post-operative home exercises. The control group will receive standard postoperative home exercises alone and will be asked to refrain from cycling during the eight-week intervention period.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 24 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Central Jutland Regional Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- Aalborg University
- Responsible party
- Principal investigator, Mette Garval, Central Jutland Regional Hospital
- Investigators
- David H Christiansen, Professor, Study chair, University Clinic for Orthopaedic Pathways (UCOP), Elective Surgery Centre, Regional Hospital Silkeborg, Regional Hospital Central Jutland, DenmarkMette Garval, MSc, Principal investigator, University Clinic for Orthopaedic Pathways (UCOP), Elective Surgery Centre, Regional Hospital Silkeborg, Regional Hospital Central Jutland, Denmark
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07838012
- Sponsor's protocol ID
- 654615
- Other IDs
- A4560, R248-A9052, R251-A9053
- Acronym
- KNEE-CYCLE
- Status last verified
- Oct 2026
- First submitted
- 3 Sep 2026
- Last updated
- 2 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be made available to other researchers. No plan is in place to share individual participant data outside the research group.
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Feasibility of Adding Early Home-based Cycling to Standard Exercises After Knee Arthroplasty: A Pilot Randomised Controlled Trial
- ClinicalTrials.gov ID
- NCT07838012
- Acronym / sponsor ID
- KNEE-CYCLE / 654615
- Conditions
- Knee Osteoarthritis, Knee Arthroplasty
- Keywords
- Knee arthroplasty, Postoperative rehabilitation, Home-based rehabilitation, Stationary cycling, Feasibility study, Postoperative recovery
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 24 participants (estimated)
- Lead sponsor
- Central Jutland Regional HospitalUniversity, hospital or other
- Collaborators
- Aalborg University
- Study start
- 21 Sep 2026 (actual)
- Primary completion
- May 2027 (estimated)
- Study completion
- Mar 2028 (estimated)
- First posted
- 24 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this pilot clinical trial is to evaluate whether an early, home-based stationary cycling programme, provided in addition to standard postoperative home exercises, is feasible and acceptable for patients recovering from knee arthroplasty. It will also inform the design of a larger clinical trial examining the effects of adding early cycling to standard postoperative home exercises on postoperative outcomes.
The main questions it aims to answer are:
- Can the cycling programme and planned study procedures be delivered as intended?
- Are participants willing and able to take part in the study and follow the planned interventions?
- Do participants find the cycling programme and outcome assessments acceptable?
- What changes, if any, are needed before conducting a larger clinical trial?
Researchers will compare an early home-based stationary cycling programme provided in addition to standard postoperative home exercises with standard postoperative home exercises alone.
Participants will:
- Be randomly assigned to either the cycling group or the standard exercise group (control group) two weeks after surgery.
- If assigned to the cycling group, perform 30 minutes of stationary cycling at home at least five days per week for eight weeks in addition to the standard postoperative home exercise programme.
- If assigned to the control group, follow the standard postoperative home exercise programme and refrain from structured cycling during the eight-week intervention period.
- Complete questionnaires and physical assessments at baseline and follow-up visits.
- Complete selected patient-reported outcome measures at 6 and 12 months after surgery.
Detailed description
This pilot randomised clinical trial will evaluate the feasibility, acceptability, and safety of an early, home-based stationary cycling intervention added to standard postoperative home exercises following knee arthroplasty. The study will also evaluate the feasibility of the study procedures required for a subsequent full-scale randomised clinical trial.
A total of 24 participants will be randomised in a 1:1 ratio to either the cycling intervention group or the control group. Both groups will receive the standard postoperative home exercise programme. Participants allocated to the cycling intervention group will additionally perform the structured home-based cycling programme for eight weeks. Participants allocated to the control group will follow the standard postoperative home exercise programme without structured cycling during the intervention period. Outcome assessors conducting the 10-week follow-up assessments will be blinded to group allocation.
The pilot will address several aspects of feasibility, including screening and recruitment, retention and completion of follow-up, adherence to the allocated study intervention, acceptability of the cycling intervention, safety, and the practicality and burden of study procedures. In the control group, adherence to the instruction to refrain from cycling during the intervention period will also be assessed. The study will additionally examine the practical and logistical feasibility of delivering the cycling intervention at home, including access to stationary bikes and, where required, provision of bikes through an external rental service.
Participants will complete selected patient-reported outcome measures preoperatively and undergo a baseline assessment two weeks after surgery, before randomisation. Preoperative assessments are included for measures for which assessment two weeks after surgery is not considered appropriate or informative. Following the baseline assessment and randomisation, participants will receive the allocated intervention. The main follow-up assessment will be conducted at 10 weeks after surgery, following completion of the eight-week cycling intervention.
Recruitment feasibility will be assessed throughout the recruitment period, including screening, eligibility, recruitment rate, and reasons for declining participation. Retention will be assessed by attendance at the 10-week follow-up and completion of planned assessments.
Intervention feasibility will include adherence to the prescribed cycling dose using the SENS Motion® activity tracker, participant-reported symptoms related to cycling, and acceptability of the intervention. In the control group, adherence to the instruction to refrain from cycling will also be assessed. Safety will be assessed by recording and describing adverse events and serious adverse events occurring during the study, including events potentially related to the cycling intervention.
Feasibility of the study procedures will include completion and burden of questionnaires and physical and performance assessments, as well as the duration and practical challenges associated with baseline and follow-up assessments, intervention delivery, equipment, and study visits. The practical and logistical feasibility of providing stationary bikes through an external rental service will also be evaluated. Participant feedback, qualitative interviews, and feedback from project staff and the clinical team will provide additional information on practical aspects of study conduct.
Completion of patient-reported outcome measures will be assessed as a separate feasibility aspect. Overall completion, completion of individual questionnaires, and missing questionnaire items will be examined to identify measures or items that may be difficult to complete, perceived as less relevant, or contribute substantially to assessment burden. These findings may inform refinement of the outcome assessment battery for the subsequent full-scale trial.
Predefined progression criteria will be used to guide the decision whether to progress to a future full-scale randomised clinical trial. The criteria address recruitment rate, adherence in the intervention and control groups, 10-week follow-up completion, and completion of baseline physical and performance assessments. A traffic-light system will be used to indicate whether progression is feasible as planned, may require modifications or further clarification, or is not recommended in its current form. The progression criteria will be considered together with additional qualitative and practical information collected during the pilot.
The primary feasibility evaluation will take place at 10 weeks after surgery. Clinical and patient-reported outcomes collected during the pilot will be analysed descriptively to provide exploratory information on postoperative recovery, outcome variability, and potential between-group differences. The Knee injury and Osteoarthritis Outcome Score (KOOS) will be assessed using the Pain, Symptoms, Activities of Daily Living (ADL), and Quality of Life subscales preoperatively and at the 10-week follow-up. These four subscales comprise the KOOS4. The proportion of participants achieving a minimally important change in KOOS4 will be explored descriptively.. These data will also contribute to planning the outcome assessment and statistical design of the subsequent full-scale randomised clinical trial.
Selected patient-reported outcome measures will also be collected at 6 and 12 months after surgery. These data will provide exploratory information on longer-term outcomes and the feasibility of longer-term follow-up. The longer-term follow-up will not determine the main feasibility evaluation at 10 weeks.
Overall, the findings from the pilot will be used to determine whether modifications to the intervention, study procedures, recruitment or retention strategies, or outcome assessment battery are required before conducting a subsequent full-scale randomised clinical trial.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Participants will be randomly assigned in a 1:1 ratio to one of two parallel groups, with randomisation stratified by type of knee arthroplasty (unicompartmental knee arthroplasty [UKA] or total knee arthroplasty [TKA]). The cycling intervention group will receive an eight-week home-based stationary cycling programme in addition to standard post-operative home exercises. The control group will receive standard postoperative home exercises alone and will be asked to refrain from cycling during the eight-week intervention period.
| Arm | Type | Receives |
|---|---|---|
| Early home-based stationary cycling | Experimental | Other: Early home-based stationary cyclingParticipants will begin a home-based stationary cycling programme two weeks after knee arthroplasty. They will perform 30 minutes of stationary cycling at least five days per week for eight weeks, in addition to the standard postoperative home-based exercise programme. |
| Usual care: home-based exercise programme | Active comparator | Other: Usual care: home-based exercise programmeParticipants will follow the standard postoperative home-based exercise programme beginning two weeks after knee arthroplasty. The programme focuses on knee mobility and muscle activation and does not include the stationary cycling intervention. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Scheduled for unilateral primary medial unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA).
- Age ≥ 18 years.
- Able to speak and read Danish.
- Daily access to a stationary bike during the intervention period, or willingness to use a stationary bike provided by the study through an external rental company for the duration of the intervention. Due to logistical constraints, loan bikes can only be provided to participants residing within approximately one hour of transport from Aarhus or Silkeborg. Participants living outside this area may participate if they have access to a stationary bike.
- Ability to use a smartphone with internet connectivity (required for completion of electronic questionnaires and using SENS motion application) or a tablet and having an email address enabling completion of electronic questionnaires.
Key exclusion criteria (8 listed)
- Previous surgery in either lower limb within 3 months before the date of knee arthroplasty or planned surgery in either lower limb within 3 months after the date of knee arthroplasty.
- Inflammatory joint disease
- Previous osteotomy around the knee or tibial condyle fracture that has been treated with osteosynthesis in the affected knee.
- Medical or physical conditions that would prevent safe participation in the cycling intervention (e.g., unstable cardiovascular, pulmonary, or chronic neurodegenerative disorders).
- Active cancer treatment, if this treatment would interfere with safe participation or adherence to the cycling protocol.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Early home-based stationary cyclingParticipants will receive individual instruction in the cycling protocol from a physiotherapist in addition to the standard postoperative home-based exercise programme described for the control group. Beginning two weeks after knee arthroplasty, participants will perform 30 minutes of home-based stationary cycling at least five days per week for eight weeks. Cycling will initially be performed at a comfortable pace with no resistance and a cadence of approximately 50-60 rpm, with cadence and resistance gradually increasing as tolerated. If unable to complete full pedal rotations, participants will perform pendulum exercises twice daily for five minutes until sufficient knee flexion is achieved. A traffic-light symptom guide will be used to adjust cycling according to pain and swelling. Participants will not be routinely referred to supervised rehabilitation during the intervention period but may contact the physiotherapy team for advice or attend a consultation if clinically indicated. | Other | Early home-based stationary cycling |
| Usual care: home-based exercise programmeParticipants will follow the standard post-operative home-based exercise programme, consisting of five exercises targeting knee range of motion and quadriceps strength, performed twice daily. At the two-week post-operative follow-up, participants will receive instruction in a second exercise programme. The exercises prescribed will be individually adjusted by a physiotherapist according to the participant's recovery and readiness for progression, including knee range of motion, functional capacity, and pain. Participants will not be routinely referred to supervised rehabilitation during the intervention period but may contact the physiotherapy team for advice or attend an additional consultation if clinically indicated. | Other | Usual care: home-based exercise programme |
Primary outcome
Screening and eligibility rate
Time frame: From study initiation until completion of recruitment.
The number of patients screened per week and the proportion who are eligible.
Recruitment rate
Time frame: From study initiation until completion of recruitment.
Number of eligible patients providing verbal agreement to participate per week and proportion of eligible patients providing verbal agreement to participate.
Declined participation among eligible patients
Time frame: From study initiation until completion of recruitment.
Number and proportion of eligible patients who decline participation after receiving study information.
Baseline assessment completion
Time frame: At baseline, before randomisation
Proportion of participants who provide written informed consent and complete the planned baseline assessment before randomisation. Completion of individual objective and physical performance assessments will also be recorded to identify any assessments that are not completed.
Retention and completion of 10-week follow-up assessments
Time frame: 10 weeks after surgery
Proportion of randomised participants who attend the 10-week follow-up assessment and proportion who complete all planned objective and physical performance assessments, reported separately for the intervention and control groups. Reasons for non-attendance and incomplete assessments will also be recorded.
Adherence to the cycling intervention
Time frame: 2 to 10 weeks after surgery.
Objective adherence to the prescribed cycling intervention, including frequency and duration of cycling sessions and the proportion of prescribed cycling days completed, assessed using the SENS Motion® sensor system.
Cycling-related pain, swelling and discomfort
Time frame: Approximately 1-2 weeks after initiation of the cycling intervention.
Participant-reported pain, swelling and discomfort related to cycling, assessed during a structured telephone assessment approximately one week after initiation of the cycling intervention. Responses will be recorded descriptively. Participants unable to complete full pedal rotations will be contacted again one week later.
Acceptability of the cycling intervention
Time frame: 10 weeks after surgery.
Participant-reported acceptability of the home-based cycling intervention assessed using selected items from the Theoretical Framework of Acceptability (TFA) questionnaire. The items assess affective attitude, burden, perceived effectiveness, self-efficacy, and overall acceptability. Responses are recorded on five-point Likert scales.
Completion of patient-reported outcome measures
Time frame: Baseline and 10 weeks after surgery
Proportion of participants who complete all planned patient-reported outcome measures (PROMs) at baseline and 10-week follow-up. Completion of individual PROMs and missing questionnaire items will also be recorded to identify PROMs with incomplete data.
Participant-reported burden of outcome assessments
Time frame: Baseline and 10 weeks after surgery
Participant-reported burden of the questionnaires and objective assessments, assessed using two yes/no questions on whether the assessments were so burdensome that the participant would choose not to participate in a similar study again. Participants answering "yes" will be asked to provide a brief reason.
Adverse events and postoperative complications
Time frame: From randomisation to 10 weeks after surgery.
Adverse events and postoperative complications reported by participants or identified in electronic health records during the study period. Events will be recorded and summarised descriptively.
18 secondary outcomes
Knee-related pain, symptoms, function and quality of life
Time frame: Pre-operatively, 10 weeks, 6 months, and 12 months after surgery.
Health-related quality of life
Time frame: Pre-operatively, 10 weeks, 6 months, and 12 months after surgery.
Mental well-being
Time frame: Pre-operatively, 10 weeks, 6 months, and 12 months after surgery.
Early recovery
Time frame: Baseline, 6 and 10 weeks after surgery.
Early change in recovery
Time frame: Baseline, 6 and 10 weeks after surgery.
Pain intensity
Time frame: Pre-operatively, at baseline, and at 6 and 10 weeks and 6 and 12 months postoperatively.
Pain distribution
Time frame: Pre-operatively, at 10 weeks and 6 and 12 months after surgery.
Pain medication use
Time frame: Pre-operatively, at baseline, and at 6 and 10 weeks and 6 and 12 months after surgery.
Knee range of motion
Time frame: Baseline and 10 weeks after surgery.
Knee range of motion
Time frame: Pre-operatively, 6 weeks, 6 months, and 12 months after surgery.
Knee swelling
Time frame: Baseline and 10 weeks after surgery.
40-metre fast-paced walk test
Time frame: Baseline and 10 weeks after surgery.
30-second chair stand test
Time frame: 10 weeks after surgery.
Stair climb test
Time frame: 10 weeks after surgery.
Pain sensitivity
Time frame: Baseline and 10 weeks after surgery.
Physical activity level
Time frame: Pre-operatively, and at 10 weeks, 6 months, and 12 months after surgery.
Objective physical activity
Time frame: During the final week of the 8-week intervention period.
Patient satisfaction and perceived outcome
Time frame: 10 weeks, and 6 and 12 months after surgery.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Oct 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be made available to other researchers. No plan is in place to share individual participant data outside the research group.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
David H Christiansen, Professor study chair
University Clinic for Orthopaedic Pathways (UCOP), Elective Surgery Centre, Regional Hospital Silkeborg, Regional Hospital Central Jutland, Denmark
Mette Garval, MSc principal investigator
University Clinic for Orthopaedic Pathways (UCOP), Elective Surgery Centre, Regional Hospital Silkeborg, Regional Hospital Central Jutland, Denmark
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Early home-based stationary cycling in people with Knee Osteoarthritis and Knee Arthroplasty, run by Central Jutland Regional Hospital at 1 site in Denmark.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Mette Garval, MSc (+45 29773935, metgar@rm.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Screening and eligibility rate (time frame: From study initiation until completion of recruitment.). The study lists 11 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Oct 2026.