Orthopedic DisorderARKNCT05412940
Accelerometry and Rehabilitation After Knee Replacement Study (ARK)
A study testing Remote monitoring of home-based exercises following knee replacement using a wearable sensor in people with Orthopedic Disorder, run by The Leeds Teaching Hospitals NHS Trust at 1 site in United Kingdom.
Trial summary
Total knee replacement (TKR) is a successful and cost-effective treatment for end-stage arthritis. Its usage is increasing due to changing population demographics and quality of life (QoL) expectations. There were almost 100,000 total knee replacements (TKR) performed in England between 2018/19. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Orthopedic Disorder
- What is being tested?
- Remote monitoring of home-based exercises following knee replacement using a wearable sensor
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 250 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 20 May 2022to 1 Sep 2026
- 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
- • Primary total knee replacement patients
- Participant is aged 18 years of age or over
- Participant is able and willing to provide written informed consent
- Participant with ability to work with smart devices
- Participant having own device (Apple iPhone or iPad or Android tablet or smartphone - minimum requirement: IOS - 12.4 or later/Android - 6.5 or later)
- Internet connection at patient's home - either Wifi or mobile internet (min. 3G)
Who cannot join
- • Participants who are unwilling or mentally and/or physically unable to adhere to study procedures
- Participants with dementia or other cognitive impairment which would prevent them from using the sensor/app
- Presence of a previous joint replacement in the same knee
- Surgical treatment of involved knee within the past 6 months (excluding arthroscopy)
- Previous orthopaedic surgery for trauma or arthritis of the knee joint (such as a previous fracture fixation or osteotomy)
- Active cancer (currently diagnosed and under treatment)
- Unable to complete all trial procedures (e.g. attend follow up visits, complete questionnaires)
- Unable to provide informed consent (cognitive disorder such as dementia, psychiatric illness)
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Leeds Teaching Hospitals NHS Trust
Leeds, West Yorkshire, LS9 7TF
About this study
Official title: Accelerometry and Rehabilitation After Knee Replacement Study (ARK): A Prospective, Randomised Controlled Trial.
Total knee replacement (TKR) is a successful and cost-effective treatment for end-stage arthritis. Its usage is increasing due to changing population demographics and quality of life (QoL) expectations. There were almost 100,000 total knee replacements (TKR) performed in England between 2018/19. After TKR, patient engagement in their rehabilitation exercises is very important but physiotherapy services are very stretched at present especially in the covid-19 era. Patient compliance with their exercises is poor at about 25%.
The use of wearable sensors (WS) following TKR is gaining lots of interest especially in the post covid-era. A recent review found five small studies which supported the feasibility of their use. WS may help with patients to engage better with their rehabilitation exercises after surgery, delivering remote physiotherapy and potentially help identify patients who may be struggling more and therefore need further targeted help with physiotherapy.
Read more
Sensors have the potential to be a cost-saving intervention for the NHS by improving efficiencies in monitoring patients by reducing number of outpatient appointments, reducing rehabilitation time, improving patient's adherence to rehabilitation schedules and increasing confidence in exercise regimes leading to improved health-related quality of life. We will conduct the first large scale study where 250 patients having TKR will be randomly chosen to either receive a WS (125 patients) against 125 patients who will have standard care (SC). Patient reported outcomes (PROMs), pain scores, objective measures of knee function and data from the sensors on how well patients engaged with their exercises will be collected. The study will also assess if WS is cost effective, at 6 months after surgery.
This study has the potential to revolutionise how pre- and post-knee replacement rehabilitation is delivered, providing an individualised, cost effective and successful solution to the current status.
- Conditions
- Orthopedic Disorder
- Being tested
- Remote monitoring of home-based exercises following knee replacement using a wearable sensor, Standard Care (in control arm)
- Medical subject headings
- Musculoskeletal Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Remote monitoring of home-based exercises following knee replacement using a wearable sensorOther
Remote monitoring of home-based exercises following knee replacement using a wearable sensor
Standard Care (in control arm)Other
Unsupervised home-based exercises following knee replacement
| Study group | Role | What they receive |
|---|---|---|
| Standard Care | Placebo comparator | Unsupervised home-based exercises following knee replacement Receives: Other: Standard Care (in control arm) |
| Wearable Sensor | Experimental | Remote monitoring of home-based exercises following knee replacement using a wearable sensor Receives: Other: Remote monitoring of home-based exercises following knee replacement using a wearable sensor |
What is being measured
The primary outcome is the main question the study is designed to answer.
Oxford Knee Score (OKS)
The Oxford Knee Score (OKS) is a 12-item, patient-reported outcome measure designed to assess pain and physical function in patients undergoing total knee replacement, with total scores ranging from 0 to 48, where higher scores represent better joint function and minimal pain.
Measured: Completion of Patient satisfaction at 6 months (primary outcome), in addition to baseline, pre-operative, 6 weeks, 12 months after surgery
Secondary outcomes (6)
Knee Injury & Osteoarthritis Outcomes Score (KOOS)
The Knee Injury and Osteoarthritis Outcome Score (KOOS) is a 42-item, patient-reported instrument assessing short- and long-term knee injury outcomes across five subscales: Pain, Symptoms, Activities of Daily Living (ADL), Sport and Recreation Function, and Knee-Related Quality of Life (each scored 0-100, where 100 indicates no knee problems).
Measured: Baseline, 6 weeks, 6 months
Self-Administered Patient Satisfaction (SAPS)
The Self-Administered Patient Satisfaction (SAPS) scale is a 4-item, patient-reported instrument designed to measure overall satisfaction following orthopedic surgery, evaluating satisfaction with current symptoms, pain relief, ability to perform home/yard work, and ability to perform recreational activities, with scores ranging from 0 to 100 where higher scores indicate greater satisfaction.
Measured: 6 weeks, 6 months
EQ-5D-5L
The EuroQol 5-Dimension 5-Level (EQ-5D-5L) is a standardized, patient-reported instrument measuring health-related quality of life across five dimensions-Mobility, Self-Care, Usual Activities, Pain/Discomfort, and Anxiety/Depression-each rated on 5 levels of severity, alongside a Visual Analogue Scale (EQ-VAS) measuring overall health from 0 to 100 (where 100 indicates the best imaginable health).
Measured: Baseline, 6 weeks, 6 months, 12 months
Wong-Baker FACES Pain Rating Scale (WB-FPRS)
The Wong-Baker FACES Pain Rating Scale (WB-FPRS) is a patient-reported visual instrument that measures pain intensity using six drawn faces depicting progressive levels of distress, scored from 0 (no hurt) to 10 (hurts worst) in increments of two, where higher scores indicate greater pain severity.
Measured: Baseline, 6 weeks, 6 months
Goniometric range of motion (ROM)
Goniometric range of motion (ROM) is an objective physical assessment measuring active and passive joint mobility in degrees using a standard goniometer, evaluating joint flexion and extension where higher degrees indicate greater range of motion.
Measured: Baseline, 6 weeks, 6 months
Timed Up and Go (TUG)
The Timed Up and Go (TUG) test is an objective functional mobility and balance assessment that measures the time (in seconds) required for a participant to rise from a standard armchair, walk 3 meters, turn, walk back, and sit down, where shorter times indicate better functional mobility and physical performance.
Measured: Baseline, pre-operative, 6 weeks, 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jun 2022
- Study start20 May 2022
- Primary completion1 Sep 2026 (estimated)
- Study completion1 Sep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Orthopedic DisorderStudies 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 250 participants (actual)
Sponsor and investigators
- Lead sponsor
- The Leeds Teaching Hospitals NHS Trust
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05412940
- Sponsor's protocol ID
- OR21/144310
- Acronym
- ARK
- Status last verified
- Aug 2026
- First submitted
- 21 Jan 2022
- Last updated
- 10 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No ethical approval to share data
Study at a glance
From the registry record, last updated by the sponsor on 10 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Accelerometry and Rehabilitation After Knee Replacement Study (ARK): A Prospective, Randomised Controlled Trial.
- ClinicalTrials.gov ID
- NCT05412940
- Acronym / sponsor ID
- ARK / OR21/144310
- Conditions
- Orthopedic Disorder
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 250 participants (actual)
- Lead sponsor
- The Leeds Teaching Hospitals NHS TrustUniversity, hospital or other
- Study start
- 20 May 2022 (actual)
- Primary completion
- 1 Sep 2026 (estimated)
- Study completion
- 1 Sep 2026 (estimated)
- First posted
- 9 Jun 2022 (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.
Total knee replacement (TKR) is a successful and cost-effective treatment for end-stage arthritis. Its usage is increasing due to changing population demographics and quality of life (QoL) expectations. There were almost 100,000 total knee replacements (TKR) performed in England between 2018/19. After TKR, patient engagement in their rehabilitation exercises is very important but physiotherapy services are very stretched at present especially in the covid-19 era. Patient compliance with their exercises is poor at about 25%.
The use of wearable sensors (WS) following TKR is gaining lots of interest especially in the post covid-era. A recent review found five small studies which supported the feasibility of their use. WS may help with patients to engage better with their rehabilitation exercises after surgery, delivering remote physiotherapy and potentially help identify patients who may be struggling more and therefore need further targeted help with physiotherapy.
Sensors have the potential to be a cost-saving intervention for the NHS by improving efficiencies in monitoring patients by reducing number of outpatient appointments, reducing rehabilitation time, improving patient's adherence to rehabilitation schedules and increasing confidence in exercise regimes leading to improved health-related quality of life. We will conduct the first large scale study where 250 patients having TKR will be randomly chosen to either receive a WS (125 patients) against 125 patients who will have standard care (SC). Patient reported outcomes (PROMs), pain scores, objective measures of knee function and data from the sensors on how well patients engaged with their exercises will be collected. The study will also assess if WS is cost effective, at 6 months after surgery.
This study has the potential to revolutionise how pre- and post-knee replacement rehabilitation is delivered, providing an individualised, cost effective and successful solution to the current status.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Standard Care | Placebo comparator | Other: Standard Care (in control arm)Unsupervised home-based exercises following knee replacement |
| Wearable Sensor | Experimental | Other: Remote monitoring of home-based exercises following knee replacement using a wearable sensorRemote monitoring of home-based exercises following knee replacement using a wearable sensor |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- • Primary total knee replacement patients
Key exclusion criteria (8 listed)
- • Participants who are unwilling or mentally and/or physically unable to adhere to study procedures
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 |
|---|---|---|
| Remote monitoring of home-based exercises following knee replacement using a wearable sensorRemote monitoring of home-based exercises following knee replacement using a wearable sensor | Other | Wearable Sensor |
| Standard Care (in control arm)Unsupervised home-based exercises following knee replacement | Other | Standard Care |
Primary outcome
Oxford Knee Score (OKS)
Time frame: Completion of Patient satisfaction at 6 months (primary outcome), in addition to baseline, pre-operative, 6 weeks, 12 months after surgery
The Oxford Knee Score (OKS) is a 12-item, patient-reported outcome measure designed to assess pain and physical function in patients undergoing total knee replacement, with total scores ranging from 0 to 48, where higher scores represent better joint function and minimal pain.
6 secondary outcomes
Knee Injury & Osteoarthritis Outcomes Score (KOOS)
Time frame: Baseline, 6 weeks, 6 months
Self-Administered Patient Satisfaction (SAPS)
Time frame: 6 weeks, 6 months
EQ-5D-5L
Time frame: Baseline, 6 weeks, 6 months, 12 months
Wong-Baker FACES Pain Rating Scale (WB-FPRS)
Time frame: Baseline, 6 weeks, 6 months
Goniometric range of motion (ROM)
Time frame: Baseline, 6 weeks, 6 months
Timed Up and Go (TUG)
Time frame: Baseline, pre-operative, 6 weeks, 6 months
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 10 Sep 2026.
- Individual participant dataSharing planned: No. No ethical approval to share data
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Remote monitoring of home-based exercises following knee replacement using a wearable sensor in people with Orthopedic Disorder, run by The Leeds Teaching Hospitals NHS Trust at 1 site in United Kingdom.
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 6 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: under way, not looking for participants, as of the sponsor's last update on 10 Sep 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 United Kingdom. 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. Some participants in this study may receive a placebo. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Oxford Knee Score (OKS) (time frame: Completion of Patient satisfaction at 6 months (primary outcome), in addition to baseline, pre-operative, 6 weeks, 12 months after surgery). 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 10 Sep 2026.