Platelet Rich Plasma InjectionNCT07339137
The Effects of Intra-articular and Peri-articular Platelet-rich Plasma (PRP) Injections ın Chronic Knee Osteoarthritis
A study testing Conservative Therapy, Intra-Articular PRP and Peri-Articular PRP in people with Platelet Rich Plasma Injection and Ultrasonography, run by Ankara City Hospital Bilkent at 1 site in Turkey (Türkiye).
Trial summary
The primary objective of this study is to evaluate and compare the effectiveness of ultrasound-guided combined intra-articular and peri-articular platelet-rich plasma (PRP) injections with intra-articular PRP injections alone in patients with chronic knee osteoarthritis (OA). Read more about this study
- Who is it for?
- Ages 40 to 65 years
- Conditions the study is for
- Platelet Rich Plasma Injection, Ultrasonography, Gonarthrosis
- What is being tested?
- Conservative Therapy, Intra-Articular PRP and Peri-Articular PRP
- Type of treatment
- Injection or infusion, Surgery or procedure, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 42 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Aug 2025to 30 Apr 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 40 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age between 40 and 65 years.
- Patients with significant medial knee pain who have not responded to conservative treatment for at least 3 months.
- Patients diagnosed with knee osteoarthritis according to the American College of Rheumatology (ACR) criteria and with Kellgren-Lawrence grade 2 or 3 radiographic osteoarthritis.
- Intact cognitive function.
- Willingness to participate in the study and provide signed informed consent.
- Visual Analog Scale (VAS) score of 4 or higher.
Who cannot join
- History of previous knee trauma or surgery.
- Physical therapy, intra-articular steroid, or hyaluronic acid injections in the knee within the last 3 months.
- Active oncological diseases.
- Local infection, sepsis, wounds, or scars in the injection area.
- Systemic infections, hepatitis, or immunosuppression.
- Bleeding diathesis or irregular International Normalized Ratio (INR) due to oral warfarin use.
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- Inflammatory arthropathies.
- Uncontrolled hypertension, uncontrolled diabetes mellitus, decompensated heart failure, coronary artery disease, or asthma.
- Suspected or confirmed pregnancy.
- Use of corticosteroids or opioids.
- Anemia.
- Body mass index (BMI) greater than 35.
- Allergy to citrate.
- Use of nonsteroidal anti-inflammatory drugs (NSAIDs) within the last week that may affect platelet function analyzer-100 (PFA-100) activity.
- Physical examination findings suggestive of patellar retinaculum, meniscus, or cruciate ligament injury.
- General health impairment or lack of cooperation.
- Refusal to participate in the study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Ankara Bilkent City Hospital, Physical Therapy and Rehabilitation Hospital
Ankara, Çankaya, 06800
Rıdvan E ÇELİK, +905078414386, ridvancelik94@gmail.com
About this study
Official title: The Effects of Platelet-rich Plasma (PRP) Injections Administered Into Intra-articular and Periarticular Regions Under Ultrasound Guidance in Chronic Knee Osteoarthritis on Pain, Function, Activities of Daily Living, Medial Collateral Ligament (MCL) and Distal Femoral Cartilage Thickness
The primary objective of this study is to evaluate and compare the effectiveness of ultrasound-guided combined intra-articular and peri-articular platelet-rich plasma (PRP) injections with intra-articular PRP injections alone in patients with chronic knee osteoarthritis (OA). The study specifically examines the effects of these treatment approaches on pain, physical function, activities of daily living, and structural parameters, including medial collateral ligament (MCL) thickness and distal femoral cartilage thickness.
Osteoarthritis is a degenerative joint disease characterized by progressive cartilage erosion, osteophyte formation, and subchondral sclerosis, leading to pain, stiffness, and functional disability. It is the most common form of arthritis and a leading cause of disability worldwide, affecting approximately 300 million individuals. Although the knee is the most frequently involved joint, OA is now recognized as a whole-joint disease, involving not only cartilage degeneration but also pathological changes in subchondral bone, synovium, and surrounding extra-articular structures.
Read more
Platelet-rich plasma is an autologous concentration of platelets suspended in a small volume of plasma and contains a variety of bioactive growth factors, such as transforming growth factor-beta (TGF-β), platelet-derived growth factor (PDGF), and vascular endothelial growth factor (VEGF). These factors play a crucial role in promoting cell proliferation, angiogenesis, and tissue repair. In knee OA, PRP has been shown to reduce matrix metalloproteinase (MMP) activity, particularly MMP-13, enhance endogenous hyaluronic acid production, and support chondrogenesis. Although intra-articular PRP injections are widely accepted as a safe and effective treatment and have demonstrated superiority over placebo and hyaluronic acid in long-term follow-up studies, most existing research has focused exclusively on intra-articular applications.
Knee OA is a multifactorial condition frequently associated with extra-articular pathologies, including ligament laxity, peri-articular edema, and soft tissue inflammation. Limiting treatment to the intra-articular space alone may therefore overlook these important contributors to pain and functional impairment. Emerging evidence suggests that a combined treatment approach targeting both intra-articular and peri-articular structures may provide superior outcomes in terms of pain reduction and functional improvement.
This prospective randomized controlled trial will include 42 patients aged 40-65 years with chronic knee OA classified as Kellgren-Lawrence grade 2 or 3. Participants will be randomly assigned to one of three groups: a control group receiving conservative treatment only (exercise therapy and lifestyle modifications), a group receiving conservative treatment plus ultrasound-guided intra-articular PRP injections, and a third group receiving conservative treatment plus combined ultrasound-guided intra-articular and peri-articular PRP injections targeting the MCL and pes anserinus regions.
Clinical outcomes will be assessed using validated instruments, including the Visual Analog Scale (VAS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Short Form-36 (SF-36) Quality of Life Scale. In addition, ultrasonographic measurements of MCL thickness and distal femoral cartilage thickness will be performed to evaluate structural changes. By investigating the additional value of peri-articular PRP injections, this study aims to contribute to the development of more comprehensive and effective injection protocols for the management of chronic knee osteoarthritis.
Read the detailed description
Osteoarthritis (OA) is a dynamic condition characterized by a disruption in the balance between anabolic and catabolic processes of joint matrix molecules, favoring catabolism. Although OA is primarily recognized for cartilage degeneration, its pathogenesis involves a complex inflammatory and degenerative process affecting the entire joint unit, including subchondral bone, synovium, and surrounding soft tissues. Platelet-rich plasma (PRP) has emerged as an effective and safe treatment option for knee OA, particularly for patients who are unable to tolerate oral pharmacological therapies or wish to delay surgical intervention. PRP promotes tissue healing through the release of various growth factors from platelet alpha granules, which enhance cellular proliferation, stimulate angiogenesis, and reduce the activity of inflammatory mediators.
Current literature predominantly focuses on the efficacy of intra-articular PRP applications. However, knee OA is a multifactorial disease frequently accompanied by extra-articular pathologies, such as ligament laxity, edema, and peri-articular soft tissue inflammation. An exclusive focus on the intra-articular space may therefore overlook these extra-articular contributors to pain and functional impairment. This study is based on the hypothesis that a combined treatment approach targeting both the intra-articular environment and peri-articular structures-specifically the medial collateral ligament (MCL) and pes anserinus-will result in superior clinical outcomes compared to intra-articular treatment alone.
The use of ultrasound (USG) guidance in this study ensures accurate needle placement and enables objective assessment of structural changes. While intra-articular PRP has been shown to be more effective than hyaluronic acid or saline injections at 6- to 12-month follow-ups, evidence regarding the additional benefits of peri-articular PRP injections remains limited. To our knowledge, this study will be among the few randomized controlled trials comparing combined intra-articular and peri-articular PRP application with isolated intra-articular PRP treatment. Moreover, by evaluating changes in MCL thickness and distal femoral cartilage thickness using USG, this study aims to provide objective structural data to the existing literature.
In this prospective randomized controlled trial, 42 patients will be allocated into three groups. Group 1 (control group) will receive conservative treatment consisting of exercise therapy, lifestyle modifications, and patient education. Group 2 will receive conservative treatment in addition to three sessions of USG-guided intra-articular PRP injections administered at one-week intervals. Group 3 will receive conservative treatment plus three sessions of combined USG-guided intra-articular and peri-articular PRP injections, with peri-articular injections targeting the MCL origin and insertion sites as well as the pes anserinus tendon insertion.
All PRP applications will be performed using a standardized preparation kit and a photo-activation system to maximize growth factor release. Patients will be evaluated at baseline and followed up at 1 week and 3 months post-treatment using validated outcome measures, including the Visual Analog Scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Short Form-36 (SF-36), along with ultrasonographic assessments to evaluate pain, function, and structural regeneration.
- Being tested
- Conservative Therapy, Intra-Articular PRP, Peri-Articular PRP
- Keywords
- knee osteoarthritis, periarticular, PRP, USG, Femoral Cartilage, Medial Collateral Ligament
- Medical subject headings
- Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Conservative TherapyBehavioural
Patients will receive guidance on conservative exercise therapy and lifestyle modifications. Exercise instruction forms will be provided, and patients will be shown how to perform the exercises correctly. Strengthening, stretching, and joint range of motion exercises targeting the quadriceps and hamstring muscle groups will be performed twice daily for 10 repetitions throughout the treatment period. Adherence will be monitored during follow-up visits.
Intra-Articular PRPProcedure or surgery
Patients will receive intra-articular platelet-rich plasma (PRP) injections three times at one-week intervals. Following the PRP injections, patients will receive standard post-procedure recommendations, including resting the knee joint for 1-2 days, avoiding aggressive exercise, refraining from using nonsteroidal anti-inflammatory drugs (NSAIDs), and applying warm compresses as needed.
Peri-Articular PRPProcedure or surgery
Patients will receive peri-articular platelet-rich plasma (PRP) injections three times at one-week intervals. Following the PRP injections, patients will receive standard post-procedure recommendations, including resting the knee joint for 1-2 days, avoiding aggressive exercise, refraining from using nonsteroidal anti-inflammatory drugs (NSAIDs), and applying warm compresses as needed.
Peri-articular injections will be administered under ultrasound (USG) guidance to the origin and insertion sites of the medial collateral ligament (MCL), relevant joint areas, and the insertion points of the pes anserinus tendons.
| Study group | Role | What they receive |
|---|---|---|
| Control Group | Active comparator | Patients receiving guidance on conservative exercise therapy and lifestyle chang Receives: Behavioral: Conservative Therapy |
| Intra-articular PRP | Active comparator | Patients receiving intra-articular PRP therapy in addition to guidance on conservative exercise therapy and lifestyle chang Receives: Behavioral: Conservative Therapy; Procedure: Intra-Articular PRP |
| Combinated PRP (Intra and peri-articular PRP) | Active comparator | Patients receiving combined (periarticular and intraarticular PRP therapy) in addition to guidance on conservative exercise therapy and lifestyle chang Receives: Behavioral: Conservative Therapy; Procedure: Intra-Articular PRP; Procedure: Peri-Articular PRP |
What is being measured
The primary outcome is the main question the study is designed to answer.
VAS (Visual Analog Scale)
The visual analog scale (VAS) is a widely accepted measurement tool in the scientific literature used to quantify subjective variables that cannot be directly measured numerically. It consists of a 100-mm horizontal line, with each end representing the extreme limits of the parameter being assessed, ranging from no pain to very severe pain. Patients are asked to mark the point on the line that best reflects their current pain intensity. The distance measured from the no-pain endpoint to the patient's mark indicates the level of pain. The VAS is a safe, easy-to-use, and valid instrument for assessing pain intensity.
Measured: Pain measurements using the VAS will be obtained at baseline (week 0), 1 week after completion of treatment (week 3), and 3 months after completion of treatment (week 14).
WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index)
The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a valid and reliable disease-specific instrument widely used to assess disability in patients with osteoarthritis. It consists of three subscales: pain (5 items), stiffness (2 items), and physical function (17 items). Each item is scored on a Likert scale ranging from 0 to 4, reflecting the level of impairment. Subscale scores are calculated separately and combined to yield a total score ranging from 0 to 100, with higher scores indicating increased pain and stiffness and greater impairment in physical function. The Turkish validity and reliability of the WOMAC were established by Tüzün and colleagues.
Measured: The WOMAC will be assessed at baseline (week 0), 1 week after completion of treatment (week 3), and 3 months after completion of treatment (week 14).
Secondary outcomes (3)
SF-36 (Short Form 36 Health Survey)
The Short Form-36 (SF-36) is a widely used instrument for assessing patients' overall health status and quality of life, with established validity and reliability in Turkish populations. The scale consists of 36 items across 8 subscales: physical functioning, role limitations due to physical health, bodily pain, general health, vitality, social functioning, role limitations due to emotional health, and mental health. Each item is scored individually, and scores are calculated to produce a total score ranging from 0 to 100, with higher scores indicating better quality of life and lower scores indicating poorer quality of life.
Measured: Quality of life will be assessed using the SF-36 at baseline (week 0), 1 week after completion of treatment (week 3), and 3 months after completion of treatment (week 14).
Distal femoral cartilage thickness
The distal femoral cartilage thickness of all participants will be assessed by the same researcher experienced in musculoskeletal ultrasonography using an ultrasound device (Logiq P5, GE Medical Systems, USA) equipped with a linear probe operating at a frequency of 5-12 megahertz (MHz). Measurements will be performed with participants in the supine position and knees in maximum flexion. The ultrasound probe will be positioned perpendicular to the articular surface of the femur by placing it transversely on the upper edge of the patella. Cartilage will be identified as a hypoechoic structure located between the suprapatellar fat pad and the bone cortex. Thickness measurements will be taken at three sites: the midpoint of the medial condyle, the intercondylar notch, and the lateral condyle. Measurements will be based on the distance between the bone-cartilage interface and the cartilage-fat pad interface.
Measured: Distal femoral cartilage thickness will be measured at baseline (week 0), 1 week after completion of treatment (week 3), and 3 months after completion of treatment (week 14) for each participant.
Medial Collateral Ligament thickness
The medial collateral ligament (MCL) of all participants will be assessed by the same researcher experienced in musculoskeletal ultrasonography using a linear probe ultrasound device (Logiq P5, GE Medical Systems, USA) operating at a frequency of 5-12 megahertz (MHz). During assessment, participants will be positioned supine with their knees fully extended. After visualizing the joint space, the MCL will be imaged in the vertical plane along the medial side of the knee. Thickness measurements will be taken at two points: approximately 1 cm proximal to the joint line on the femoral side and 1 cm distal to the joint line on the tibial side.
Measured: Medial collateral ligament (MCL) thickness will be measured at baseline (week 0), 1 week after completion of treatment (week 3), and 3 months after completion of treatment (week 14) for each participant.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jan 2026
- Study start1 Aug 2025
- Primary completion1 Feb 2026 (estimated)
- Study completion30 Apr 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for Platelet Rich Plasma InjectionStudies of the same condition, open and under way.
- More trials run by Ankara City Hospital BilkentThe 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
- Model description
- This randomized, parallel-group study will compare the effects of conservative treatment alone, intra-articular platelet-rich plasma (PRP) injections in addition to conservative treatment, and combined intra-articular and peri-articular PRP injections in patients with chronic knee osteoarthritis (OA). Participants will be assigned to one of three intervention groups. Clinical and ultrasonographic outcomes will be assessed at baseline, 1 week after completion of treatment, and 3 months after completion of treatment.
- Masking
- None (open label)
- Enrolment
- 42 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ankara City Hospital Bilkent
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, RIDVAN ÇELİK, Ankara City Hospital Bilkent
- Investigators
- Emre ADIGÜZEL, Prof. Dr., Study director, Ankara Bilkent City Hospital Physical Therapy and Rehabilitation Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07339137
- Sponsor's protocol ID
- E2-25-9883
- Status last verified
- Jan 2026
- First submitted
- 2 Jan 2026
- Last updated
- 15 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Shen L, Yuan T, Chen S, Xie X, Zhang C. The temporal effect of platelet-rich plasma on pain and physical function in the treatment of knee osteoarthritis: systematic review and meta-analysis of randomized controlled trials. J Orthop Surg Res. 2017 Jan 23;12(1):16. doi: 10.1186/s13018-017-0521-3.
PubMed 28115016Sit RWS, Wu RWK, Law SW, Zhang DD, Yip BHK, Ip AKK, Rabago D, Reeves KD, Wong SYS. Intra-articular and extra-articular platelet-rich plasma injections for knee osteoarthritis: A 26-week, single-arm, pilot feasibility study. Knee. 2019 Oct;26(5):1032-1040. doi: 10.1016/j.knee.2019.06.018. Epub 2019 Jul 30.
PubMed 31375446Tao X, Aw AAL, Leeu JJ, Bin Abd Razak HR. Three Doses of Platelet-Rich Plasma Therapy Are More Effective Than One Dose of Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review and Meta-analysis. Arthroscopy. 2023 Dec;39(12):2568-2576.e2. doi: 10.1016/j.arthro.2023.05.018. Epub 2023 May 24.
PubMed 37236291Mascarenhas R, Saltzman BM, Fortier LA, Cole BJ. Role of platelet-rich plasma in articular cartilage injury and disease. J Knee Surg. 2015 Feb;28(1):3-10. doi: 10.1055/s-0034-1384672. Epub 2014 Jul 28.
PubMed 25068847Aras B, Celik R, Tezen O, Adiguzel E. Associations of medial collateral ligament and cartilage thickness with clinical outcomes in medial knee osteoarthritis: a cross-sectional study. Clin Rheumatol. 2026 Jan;45(1):441-447. doi: 10.1007/s10067-025-07809-x. Epub 2025 Nov 17.
PubMed 41247668Pane RV, Setiyaningsih R, Widodo G, Al Hajiri AZZ, Salsabil JR. Femoral Cartilage Thickness in Knee Osteoarthritis Patients and Healthy Adults: An Ultrasound Measurement Comparison. ScientificWorldJournal. 2023 Feb 17;2023:3942802. doi: 10.1155/2023/3942802. eCollection 2023.
PubMed 36845755Testa G, Giardina SMC, Culmone A, Vescio A, Turchetta M, Cannavo S, Pavone V. Intra-Articular Injections in Knee Osteoarthritis: A Review of Literature. J Funct Morphol Kinesiol. 2021 Feb 3;6(1):15. doi: 10.3390/jfmk6010015.
PubMed 33546408
Study at a glance
From the registry record, last updated by the sponsor on 15 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Platelet-rich Plasma (PRP) Injections Administered Into Intra-articular and Periarticular Regions Under Ultrasound Guidance in Chronic Knee Osteoarthritis on Pain, Function, Activities of Daily Living, Medial Collateral Ligament (MCL) and Distal Femoral Cartilage Thickness
- ClinicalTrials.gov ID
- NCT07339137
- Acronym / sponsor ID
- E2-25-9883
- Keywords
- knee osteoarthritis, periarticular, PRP, USG, Femoral Cartilage, Medial Collateral Ligament
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 42 participants (estimated)
- Lead sponsor
- Ankara City Hospital BilkentUniversity, hospital or other
- Study start
- 1 Aug 2025 (actual)
- Primary completion
- 1 Feb 2026 (estimated)
- Study completion
- 30 Apr 2026 (estimated)
- First posted
- 14 Jan 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 primary objective of this study is to evaluate and compare the effectiveness of ultrasound-guided combined intra-articular and peri-articular platelet-rich plasma (PRP) injections with intra-articular PRP injections alone in patients with chronic knee osteoarthritis (OA). The study specifically examines the effects of these treatment approaches on pain, physical function, activities of daily living, and structural parameters, including medial collateral ligament (MCL) thickness and distal femoral cartilage thickness.
Osteoarthritis is a degenerative joint disease characterized by progressive cartilage erosion, osteophyte formation, and subchondral sclerosis, leading to pain, stiffness, and functional disability. It is the most common form of arthritis and a leading cause of disability worldwide, affecting approximately 300 million individuals. Although the knee is the most frequently involved joint, OA is now recognized as a whole-joint disease, involving not only cartilage degeneration but also pathological changes in subchondral bone, synovium, and surrounding extra-articular structures.
Platelet-rich plasma is an autologous concentration of platelets suspended in a small volume of plasma and contains a variety of bioactive growth factors, such as transforming growth factor-beta (TGF-β), platelet-derived growth factor (PDGF), and vascular endothelial growth factor (VEGF). These factors play a crucial role in promoting cell proliferation, angiogenesis, and tissue repair. In knee OA, PRP has been shown to reduce matrix metalloproteinase (MMP) activity, particularly MMP-13, enhance endogenous hyaluronic acid production, and support chondrogenesis. Although intra-articular PRP injections are widely accepted as a safe and effective treatment and have demonstrated superiority over placebo and hyaluronic acid in long-term follow-up studies, most existing research has focused exclusively on intra-articular applications.
Knee OA is a multifactorial condition frequently associated with extra-articular pathologies, including ligament laxity, peri-articular edema, and soft tissue inflammation. Limiting treatment to the intra-articular space alone may therefore overlook these important contributors to pain and functional impairment. Emerging evidence suggests that a combined treatment approach targeting both intra-articular and peri-articular structures may provide superior outcomes in terms of pain reduction and functional improvement.
This prospective randomized controlled trial will include 42 patients aged 40-65 years with chronic knee OA classified as Kellgren-Lawrence grade 2 or 3. Participants will be randomly assigned to one of three groups: a control group receiving conservative treatment only (exercise therapy and lifestyle modifications), a group receiving conservative treatment plus ultrasound-guided intra-articular PRP injections, and a third group receiving conservative treatment plus combined ultrasound-guided intra-articular and peri-articular PRP injections targeting the MCL and pes anserinus regions.
Clinical outcomes will be assessed using validated instruments, including the Visual Analog Scale (VAS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Short Form-36 (SF-36) Quality of Life Scale. In addition, ultrasonographic measurements of MCL thickness and distal femoral cartilage thickness will be performed to evaluate structural changes. By investigating the additional value of peri-articular PRP injections, this study aims to contribute to the development of more comprehensive and effective injection protocols for the management of chronic knee osteoarthritis.
Detailed description
Osteoarthritis (OA) is a dynamic condition characterized by a disruption in the balance between anabolic and catabolic processes of joint matrix molecules, favoring catabolism. Although OA is primarily recognized for cartilage degeneration, its pathogenesis involves a complex inflammatory and degenerative process affecting the entire joint unit, including subchondral bone, synovium, and surrounding soft tissues. Platelet-rich plasma (PRP) has emerged as an effective and safe treatment option for knee OA, particularly for patients who are unable to tolerate oral pharmacological therapies or wish to delay surgical intervention. PRP promotes tissue healing through the release of various growth factors from platelet alpha granules, which enhance cellular proliferation, stimulate angiogenesis, and reduce the activity of inflammatory mediators.
Current literature predominantly focuses on the efficacy of intra-articular PRP applications. However, knee OA is a multifactorial disease frequently accompanied by extra-articular pathologies, such as ligament laxity, edema, and peri-articular soft tissue inflammation. An exclusive focus on the intra-articular space may therefore overlook these extra-articular contributors to pain and functional impairment. This study is based on the hypothesis that a combined treatment approach targeting both the intra-articular environment and peri-articular structures-specifically the medial collateral ligament (MCL) and pes anserinus-will result in superior clinical outcomes compared to intra-articular treatment alone.
The use of ultrasound (USG) guidance in this study ensures accurate needle placement and enables objective assessment of structural changes. While intra-articular PRP has been shown to be more effective than hyaluronic acid or saline injections at 6- to 12-month follow-ups, evidence regarding the additional benefits of peri-articular PRP injections remains limited. To our knowledge, this study will be among the few randomized controlled trials comparing combined intra-articular and peri-articular PRP application with isolated intra-articular PRP treatment. Moreover, by evaluating changes in MCL thickness and distal femoral cartilage thickness using USG, this study aims to provide objective structural data to the existing literature.
In this prospective randomized controlled trial, 42 patients will be allocated into three groups. Group 1 (control group) will receive conservative treatment consisting of exercise therapy, lifestyle modifications, and patient education. Group 2 will receive conservative treatment in addition to three sessions of USG-guided intra-articular PRP injections administered at one-week intervals. Group 3 will receive conservative treatment plus three sessions of combined USG-guided intra-articular and peri-articular PRP injections, with peri-articular injections targeting the MCL origin and insertion sites as well as the pes anserinus tendon insertion.
All PRP applications will be performed using a standardized preparation kit and a photo-activation system to maximize growth factor release. Patients will be evaluated at baseline and followed up at 1 week and 3 months post-treatment using validated outcome measures, including the Visual Analog Scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Short Form-36 (SF-36), along with ultrasonographic assessments to evaluate pain, function, and structural regeneration.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- This randomized, parallel-group study will compare the effects of conservative treatment alone, intra-articular platelet-rich plasma (PRP) injections in addition to conservative treatment, and combined intra-articular and peri-articular PRP injections in patients with chronic knee osteoarthritis (OA). Participants will be assigned to one of three intervention groups. Clinical and ultrasonographic outcomes will be assessed at baseline, 1 week after completion of treatment, and 3 months after completion of treatment.
| Arm | Type | Receives |
|---|---|---|
| Control Group | Active comparator | Behavioral: Conservative TherapyPatients receiving guidance on conservative exercise therapy and lifestyle chang |
| Intra-articular PRP | Active comparator | Behavioral: Conservative Therapy, Procedure: Intra-Articular PRPPatients receiving intra-articular PRP therapy in addition to guidance on conservative exercise therapy and lifestyle chang |
| Combinated PRP (Intra and peri-articular PRP) | Active comparator | Behavioral: Conservative Therapy, Procedure: Intra-Articular PRP, Procedure: Peri-Articular PRPPatients receiving combined (periarticular and intraarticular PRP therapy) in addition to guidance on conservative exercise therapy and lifestyle chang |
Who may qualify
- Ages
- 40 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age between 40 and 65 years.
- Patients with significant medial knee pain who have not responded to conservative treatment for at least 3 months.
- Patients diagnosed with knee osteoarthritis according to the American College of Rheumatology (ACR) criteria and with Kellgren-Lawrence grade 2 or 3 radiographic osteoarthritis.
- Intact cognitive function.
- Willingness to participate in the study and provide signed informed consent.
Key exclusion criteria (17 listed)
- History of previous knee trauma or surgery.
- Physical therapy, intra-articular steroid, or hyaluronic acid injections in the knee within the last 3 months.
- Active oncological diseases.
- Local infection, sepsis, wounds, or scars in the injection area.
- Systemic infections, hepatitis, or immunosuppression.
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 |
|---|---|---|
| Conservative TherapyPatients will receive guidance on conservative exercise therapy and lifestyle modifications. Exercise instruction forms will be provided, and patients will be shown how to perform the exercises correctly. Strengthening, stretching, and joint range of motion exercises targeting the quadriceps and hamstring muscle groups will be performed twice daily for 10 repetitions throughout the treatment period. Adherence will be monitored during follow-up visits. | Behavioural | Combinated PRP (Intra and peri-articular PRP), Control Group, Intra-articular PRP |
| Intra-Articular PRPPatients will receive intra-articular platelet-rich plasma (PRP) injections three times at one-week intervals. Following the PRP injections, patients will receive standard post-procedure recommendations, including resting the knee joint for 1-2 days, avoiding aggressive exercise, refraining from using nonsteroidal anti-inflammatory drugs (NSAIDs), and applying warm compresses as needed. | Procedure or surgery | Combinated PRP (Intra and peri-articular PRP), Intra-articular PRP |
| Peri-Articular PRPPatients will receive peri-articular platelet-rich plasma (PRP) injections three times at one-week intervals. Following the PRP injections, patients will receive standard post-procedure recommendations, including resting the knee joint for 1-2 days, avoiding aggressive exercise, refraining from using nonsteroidal anti-inflammatory drugs (NSAIDs), and applying warm compresses as needed. Peri-articular injections will be administered under ultrasound (USG) guidance to the origin and insertion sites of the medial collateral ligament (MCL), relevant joint areas, and the insertion points of the pes anserinus tendons. | Procedure or surgery | Combinated PRP (Intra and peri-articular PRP) |
Primary outcome
VAS (Visual Analog Scale)
Time frame: Pain measurements using the VAS will be obtained at baseline (week 0), 1 week after completion of treatment (week 3), and 3 months after completion of treatment (week 14).
The visual analog scale (VAS) is a widely accepted measurement tool in the scientific literature used to quantify subjective variables that cannot be directly measured numerically. It consists of a 100-mm horizontal line, with each end representing the extreme limits of the parameter being assessed, ranging from no pain to very severe pain. Patients are asked to mark the point on the line that best reflects their current pain intensity. The distance measured from the no-pain endpoint to the patient's mark indicates the level of pain. The VAS is a safe, easy-to-use, and valid instrument for assessing pain intensity.
WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index)
Time frame: The WOMAC will be assessed at baseline (week 0), 1 week after completion of treatment (week 3), and 3 months after completion of treatment (week 14).
The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a valid and reliable disease-specific instrument widely used to assess disability in patients with osteoarthritis. It consists of three subscales: pain (5 items), stiffness (2 items), and physical function (17 items). Each item is scored on a Likert scale ranging from 0 to 4, reflecting the level of impairment. Subscale scores are calculated separately and combined to yield a total score ranging from 0 to 100, with higher scores indicating increased pain and stiffness and greater impairment in physical function. The Turkish validity and reliability of the WOMAC were established by Tüzün and colleagues.
3 secondary outcomes
SF-36 (Short Form 36 Health Survey)
Time frame: Quality of life will be assessed using the SF-36 at baseline (week 0), 1 week after completion of treatment (week 3), and 3 months after completion of treatment (week 14).
Distal femoral cartilage thickness
Time frame: Distal femoral cartilage thickness will be measured at baseline (week 0), 1 week after completion of treatment (week 3), and 3 months after completion of treatment (week 14) for each participant.
Medial Collateral Ligament thickness
Time frame: Medial collateral ligament (MCL) thickness will be measured at baseline (week 0), 1 week after completion of treatment (week 3), and 3 months after completion of treatment (week 14) for each participant.
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 15 Jan 2026.
- Background: PubMed 28115016Shen L, Yuan T, Chen S, Xie X, Zhang C. The temporal effect of platelet-rich plasma on pain and physical function in the treatment of knee osteoarthritis: systematic review and meta-analysis of randomized controlled trials. J Orthop Surg Res. 2017 Jan 23;12(1):16. doi: 10.1186/s13018-017-0521-3.
- Background: PubMed 31375446Sit RWS, Wu RWK, Law SW, Zhang DD, Yip BHK, Ip AKK, Rabago D, Reeves KD, Wong SYS. Intra-articular and extra-articular platelet-rich plasma injections for knee osteoarthritis: A 26-week, single-arm, pilot feasibility study. Knee. 2019 Oct;26(5):1032-1040. doi: 10.1016/j.knee.2019.06.018. Epub 2019 Jul 30.
- Background: PubMed 37236291Tao X, Aw AAL, Leeu JJ, Bin Abd Razak HR. Three Doses of Platelet-Rich Plasma Therapy Are More Effective Than One Dose of Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review and Meta-analysis. Arthroscopy. 2023 Dec;39(12):2568-2576.e2. doi: 10.1016/j.arthro.2023.05.018. Epub 2023 May 24.
- Background: PubMed 25068847Mascarenhas R, Saltzman BM, Fortier LA, Cole BJ. Role of platelet-rich plasma in articular cartilage injury and disease. J Knee Surg. 2015 Feb;28(1):3-10. doi: 10.1055/s-0034-1384672. Epub 2014 Jul 28.
- Background: PubMed 41247668Aras B, Celik R, Tezen O, Adiguzel E. Associations of medial collateral ligament and cartilage thickness with clinical outcomes in medial knee osteoarthritis: a cross-sectional study. Clin Rheumatol. 2026 Jan;45(1):441-447. doi: 10.1007/s10067-025-07809-x. Epub 2025 Nov 17.
- Background: PubMed 36845755Pane RV, Setiyaningsih R, Widodo G, Al Hajiri AZZ, Salsabil JR. Femoral Cartilage Thickness in Knee Osteoarthritis Patients and Healthy Adults: An Ultrasound Measurement Comparison. ScientificWorldJournal. 2023 Feb 17;2023:3942802. doi: 10.1155/2023/3942802. eCollection 2023.
- Background: PubMed 33546408Testa G, Giardina SMC, Culmone A, Vescio A, Turchetta M, Cannavo S, Pavone V. Intra-Articular Injections in Knee Osteoarthritis: A Review of Literature. J Funct Morphol Kinesiol. 2021 Feb 3;6(1):15. doi: 10.3390/jfmk6010015.
- Individual participant dataSharing planned: No
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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.
Emre ADIGÜZEL, Prof. Dr. study director
Ankara Bilkent City Hospital Physical Therapy and Rehabilitation Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Conservative Therapy, Intra-Articular PRP and Peri-Articular PRP in people with Platelet Rich Plasma Injection and Ultrasonography, run by Ankara City Hospital Bilkent at 1 site in Turkey (Türkiye).
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 17 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 15 Jan 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 Turkey (Türkiye). 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 Rıdvan E ÇELİK (+905078414386, ridvancelik94@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
VAS (Visual Analog Scale) (time frame: Pain measurements using the VAS will be obtained at baseline (week 0), 1 week after completion of treatment (week 3), and 3 months after completion of treatment (week 14).). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07339137, which also lists 7 linked publications.
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 15 Jan 2026.