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.
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 Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
SINGLE
Enrollment
24
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.
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.
Screening and eligibility rate
The number of patients screened per week and the proportion who are eligible.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: From randomisation to 10 weeks after surgery.
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
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Time frame: 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).
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: Baseline and 10 weeks after surgery.
40-metre fast-paced walk test
Walking performance assessed using the 40-metre fast-paced walk test.
Time frame: 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.
Time frame: 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.
Time frame: 10 weeks after surgery.
Pain sensitivity
Pain sensitivity assessed using quantitative sensory testing (QST) with cuff algometry.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 10 weeks, and 6 and 12 months after surgery.