Patellar AbnormalityNCT05484141
The Effect of Blood Flow Restriction Method in Patellar Instability
A study testing Rehabilitation with blood blow restriction and Rehabilitation without blood flow restriction in people with Patellar Abnormality, run by Biruni University.
Trial summary
The blood flow restriction method, the effects of which have been frequently investigated in the literature in recent years, can produce muscle hypertrophy with low-intensity load and can be easily tolerated through to low mechanical stress, seems to be an exercise approach that can be used in the recovery of strength… Read more about this study
- Who is it for?
- Ages 18 to 40 years
- Conditions the study is for
- Patellar Abnormality
- What is being tested?
- Rehabilitation with blood blow restriction and Rehabilitation without blood flow restriction
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 34 participants
- Where
- No sites listed yet
- Study dates
- 1 Jan 2026to 30 Dec 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 to 40 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Being between the ages of 18-40 years,
- Volunteering to participate in the study,
- Having a complaint of anterior knee pain for at least 3 months,
- Having been diagnosed with unilateral minor patellar instability,
- Absence of any other ongoing clinical problems that interfere with exercise (will be questioned by the Physical Activity Readiness Questionnaire for All).
Who cannot join
- History of one or more traumatic-atraumatic patella dislocations,
- Evidence of osteoarthritis on radiological imaging (≥ Kellgren-Lawrence Stage 2)
- Having at least one of the contraindications preventing the application of blood flow restrictive exercises (Smoking, previous venous thromboembolism, risk of peripheral vascular disease (ankle-brachial index <0.9), coronary heart disease, hypertension, hemophilia, etc.),
- Previously diagnosed cardiovascular disease limiting effort capacity (Myocardial infarction, angina, exercise intolerance, etc.),
- Previously diagnosed neurological disorder or cognitive dysfunction (stroke, dementia, schizophrenia, etc.),
- Orthopedic lower extremity surgery in the last 1 year,
- Body mass index ≥ 30 kg/m2.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: The Effect of Blood Flow Restriction Applied to the Extensor Muscles on Muscle Architecture and Strength, Knee Pain, and Functions in Minor Patellar Instability
The blood flow restriction method, the effects of which have been frequently investigated in the literature in recent years, can produce muscle hypertrophy with low-intensity load and can be easily tolerated through to low mechanical stress, seems to be an exercise approach that can be used in the recovery of strength in cases with minor patellar instability and can contribute to the recovery of functional capacity without delay.
Read the detailed description
Patellar instability is defined as disruption of normal movement of the patella in the trochlear groove, symptomatic, medial-lateral displacement. Patients with patellar instability may not be able to tolerate high-intensity quadriceps exercises in the early period of strengthening programs due to pain symptoms, and therefore strength recovery may be delayed. However, it is important to restore muscle strength, especially vastus medialis obliquus strength, as early as possible in patellar instability. The blood flow restriction method, the effects of which have been frequently investigated in the literature in recent years, can produce muscle hypertrophy with low-intensity load and can be easily tolerated through to low mechanical stress, seems to be an exercise approach that can be used in the recovery of strength in cases with minor patellar instability and can contribute to the recovery of functional capacity without delay.
- Conditions
- Patellar Abnormality
- Being tested
- Rehabilitation with blood blow restriction, Rehabilitation without blood flow restriction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Rehabilitation with blood blow restrictionOther
The rehabilitation program will be applied 2 days a week, for total of 8 weeks.
Rehabilitation without blood flow restrictionOther
The rehabilitation program will be applied 2 days a week, for total of 8 weeks.
| Study group | Role | What they receive |
|---|---|---|
| With Blood Flow Restriction | Experimental | Not described Receives: Other: Rehabilitation with blood blow restriction |
| Without Blood Flow Restriction | Active comparator | Not described Receives: Other: Rehabilitation without blood flow restriction |
What is being measured
The primary outcome is the main question the study is designed to answer.
Assessment of Muscle Architecture and Hypertrophy
A portable, diagnostic B-mode ultrasound device with a linear probe will be used to evaluate the quadriceps muscle architecture. Cross-sectional areas, muscle thicknesses, fascicle lengths, and pennation angles, the architectural parameters of both thigh muscles, will be assessed by ultrasound. All assessments will be calculated as millimeters.
Measured: 8 weeks
Secondary outcomes (4)
Assessment of Muscle Strength
The concentric and eccentric strength of the knee extensor muscle (quadriceps) and its antagonist (hamstring), will be measured using the isokinetic dynamometer.
Measured: 8 weeks
Assessment of Pain
Visual Analogue Scale (VAS) will be used to evaluate the severity of pain in the knee of patients during activity, at rest, and at night. In the evaluation of pain intensity with VAS, the patient is asked to mark his pain above the 10-centimeter line defined as "0-no pain" and "10 unbearable pain" at both ends.
Measured: 8 weeks
Evaluation of Functions
The Tampa Kinesiophobia Scale (TKS) will be used to evaluate kinesiophobia. The lower extremity functional capacity of the subjects will be evaluated with the 1-minute sit-to-stand test, and the knee functions will be evaluated with the Lysholm Knee Scoring Scale and the Kujala Patellofemoral Joint Evaluation Scale, which are patient-answered scales that are recommended to be used in cases with patellar instability. In addition, fatigue determination after each application will be made with the Borg CR-10 Perceived Fatigue Scale. Scales will be filled by the face-to-face evaluation method.
Measured: 8 weeks
Evaluation of Satisfaction and Change
General satisfaction and the change in clinical status perceived by the participants will be evaluated with the 7 points Global Rating of Change Scale after the rehabilitation program. According to the scale, it is expressed as "-3: I am much worse, -2: I am worse, -1: I am a little worse, 0: No change, 1: I am a little better, 2: I am better, 3: I am much better".
Measured: 8th week
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Aug 2022
- Study start1 Jan 2026 (estimated)
- Primary completion1 Dec 2026 (estimated)
- Study completion30 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Patellar AbnormalityStudies of the same condition, open and under way.
- More trials run by Biruni UniversityThe sponsor's other registered studies.
- 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
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 34 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Biruni University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Begum Kara Kaya, Biruni University
- Investigators
- Ayşe Zengin Alpözgen, PhD, Study director, Istanbul University - Cerrahpasa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05484141
- Sponsor's protocol ID
- PFI
- Status last verified
- Dec 2025
- First submitted
- 26 Jul 2022
- Last updated
- 26 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Blood Flow Restriction Applied to the Extensor Muscles on Muscle Architecture and Strength, Knee Pain, and Functions in Minor Patellar Instability
- ClinicalTrials.gov ID
- NCT05484141
- Acronym / sponsor ID
- PFI
- Conditions
- Patellar Abnormality
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 34 participants (estimated)
- Lead sponsor
- Biruni UniversityUniversity, hospital or other
- Study start
- 1 Jan 2026 (estimated)
- Primary completion
- 1 Dec 2026 (estimated)
- Study completion
- 30 Dec 2026 (estimated)
- First posted
- 2 Aug 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.
The blood flow restriction method, the effects of which have been frequently investigated in the literature in recent years, can produce muscle hypertrophy with low-intensity load and can be easily tolerated through to low mechanical stress, seems to be an exercise approach that can be used in the recovery of strength in cases with minor patellar instability and can contribute to the recovery of functional capacity without delay.
Detailed description
Patellar instability is defined as disruption of normal movement of the patella in the trochlear groove, symptomatic, medial-lateral displacement. Patients with patellar instability may not be able to tolerate high-intensity quadriceps exercises in the early period of strengthening programs due to pain symptoms, and therefore strength recovery may be delayed. However, it is important to restore muscle strength, especially vastus medialis obliquus strength, as early as possible in patellar instability. The blood flow restriction method, the effects of which have been frequently investigated in the literature in recent years, can produce muscle hypertrophy with low-intensity load and can be easily tolerated through to low mechanical stress, seems to be an exercise approach that can be used in the recovery of strength in cases with minor patellar instability and can contribute to the recovery of functional capacity without delay.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| With Blood Flow Restriction | Experimental | Other: Rehabilitation with blood blow restriction |
| Without Blood Flow Restriction | Active comparator | Other: Rehabilitation without blood flow restriction |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Being between the ages of 18-40 years,
- Volunteering to participate in the study,
- Having a complaint of anterior knee pain for at least 3 months,
- Having been diagnosed with unilateral minor patellar instability,
- Absence of any other ongoing clinical problems that interfere with exercise (will be questioned by the Physical Activity Readiness Questionnaire for All).
Key exclusion criteria (7 listed)
- History of one or more traumatic-atraumatic patella dislocations,
- Evidence of osteoarthritis on radiological imaging (≥ Kellgren-Lawrence Stage 2)
- Having at least one of the contraindications preventing the application of blood flow restrictive exercises (Smoking, previous venous thromboembolism, risk of peripheral vascular disease (ankle-brachial index <0.9), coronary heart disease, hypertension, hemophilia, etc.),
- Previously diagnosed cardiovascular disease limiting effort capacity (Myocardial infarction, angina, exercise intolerance, etc.),
- Previously diagnosed neurological disorder or cognitive dysfunction (stroke, dementia, schizophrenia, etc.),
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 |
|---|---|---|
| Rehabilitation with blood blow restrictionThe rehabilitation program will be applied 2 days a week, for total of 8 weeks. | Other | With Blood Flow Restriction |
| Rehabilitation without blood flow restrictionThe rehabilitation program will be applied 2 days a week, for total of 8 weeks. | Other | Without Blood Flow Restriction |
Primary outcome
Assessment of Muscle Architecture and Hypertrophy
Time frame: 8 weeks
A portable, diagnostic B-mode ultrasound device with a linear probe will be used to evaluate the quadriceps muscle architecture. Cross-sectional areas, muscle thicknesses, fascicle lengths, and pennation angles, the architectural parameters of both thigh muscles, will be assessed by ultrasound. All assessments will be calculated as millimeters.
4 secondary outcomes
Assessment of Muscle Strength
Time frame: 8 weeks
Assessment of Pain
Time frame: 8 weeks
Evaluation of Functions
Time frame: 8 weeks
Evaluation of Satisfaction and Change
Time frame: 8th week
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 26 Dec 2025.
- Individual participant dataSharing planned: No
Related trials for Patellar Abnormality
RecruitingObservational study
Rare Disease Patient Registry & Natural History Study - Coordination of Rare Diseases at Sanford
Rare Disorders, Undiagnosed Disorders
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.
Ayşe Zengin Alpözgen, PhD study director
Istanbul University - Cerrahpasa
Questions about this trial
What is this clinical trial studying?
A study testing Rehabilitation with blood blow restriction and Rehabilitation without blood flow restriction in people with Patellar Abnormality, run by Biruni University.
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 7 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: opening soon, as of the sponsor's last update on 26 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
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 Begüm KARA KAYA, MSc (+905355720021, bkara@biruni.edu.tr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Assessment of Muscle Architecture and Hypertrophy (time frame: 8 weeks). 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 26 Dec 2025.