An interventional study of ozone injection and Exercise in Knee Osteoarthritis, sponsored by Kayseri City Hospital. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 40 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-07-01.
Sponsored by Kayseri City Hospital · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to evaluate the clinical efficacy of different doses of intra-articular ozone injections combined with exercise in patients aged 40-75 diagnosed with Grade 2-3 knee osteoarthritis.
The main questions it aims to answer are:
Participants will:
This clinical trial is designed as a prospective, randomized, controlled study to investigate the dose-dependent therapeutic effects of intra-articular ozone therapy in patients with Grade 2-3 knee osteoarthritis.
Eligible participants aged 40-75 with a confirmed diagnosis of knee osteoarthritis (Kellgren-Lawrence Grade 2 or 3) will be recruited. Participants will be allocated into one of four parallel groups by computerized randomization.
All patients allocated to the ozone intervention groups will receive a total of 3 sessions of intra-articular ozone injections, administered once a week for three consecutive weeks. For all three treatment groups, the injection volume will be at 10 mL per session, while the ozone concentrations will vary according to the assigned group as follows:
Ozone 10 µg + Exercise: 10 mL of ozone injection at a concentration of 10 µg/mL + Home exercise program.
Ozone 15 µg + Exercise: 10 mL of ozone injection at a concentration of 15 µg/mL + Home exercise program.
Ozone 20 µg + Exercise: 10 mL of ozone injection at a concentration of 20 µg/mL + Home exercise program.
Exercise Alone (Control): Home exercise program alone.
All participants across all four groups will be prescribed a structured home exercise program. This program includes joint range of motion (ROM) exercises; strengthening exercises and flexibility exercises.
The home program will be performed for 30 minutes per day, 5 days a week, throughout the 3-month study period. To improve patient adherence to exercise, patients will be provided with an exercise diary and also an analgesic diary to track analgesic use.
Clinical and functional evaluations will be performed at four distinct time points: baseline (pre-treatment), immediately after the 3rd injection session (post-treatment), 1 month after the last ozone injection, and 3 months after the last ozone injection. The clinical and functional status of the participants will be evaluated using the Numerical Rating Scale (NRS) for pain severity, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for knee-specific symptoms and physical function, the Lequesne Algofunctional Index for osteoarthritis severity and physical disability, and the EuroQol 5-Dimension (EQ-5D) questionnaire for overall health-related quality of life. Additionally, objective functional capacity, dynamic balance, and mobility will be assessed using the 6-Minute Walk Test (6MWT) and the Timed Up and Go (TUG) test.
3,292 studies on the registry are indexed under Osteoarthritis, Knee; 623 are open to participants now.
This study's planned enrollment of 80 is above the median of 68 across 2,714 interventional studies indexed under Osteoarthritis, Knee.
Browse Osteoarthritis, Knee studies →Kayseri City Hospital is the lead sponsor of 49 studies on the registry; 15 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
10 mL of ozone injection at a concentration of 10 µg/mL + Home exercise program
Other: ozone injection · Behavioral: Exercise
10 mL of ozone injection at a concentration of 15 µg/mL + Home exercise program
Other: ozone injection · Behavioral: Exercise
10 mL of ozone injection at a concentration of 20 µg/mL + Home exercise program
Other: ozone injection · Behavioral: Exercise
Home exercise program alone
Behavioral: Exercise
All patients allocated to the ozone intervention groups will receive a total of 3 sessions of intra-articular ozone injections, administered once a week for three consecutive weeks. For all three treatment groups, the injection volume will be 10 mL per session, while the ozone concentrations will vary according to the assigned group as Ozone 10 µg/mL + Exercise, Ozone 15 µg/mL + Exercise, and Ozone 20 µg/mL + Exercise.
Also known as: Intra-articular Ozone Injection
All participants across all four groups will be prescribed a structured home exercise program. This program includes joint range of motion (ROM) exercises; strengthening exercises (including quadriceps strengthening, hamstring strengthening, hip abductor strengthening, and seated calf raises); and flexibility exercises (including hamstring stretching, gastrocnemius-soleus stretching, and quadriceps stretching). The home program will be performed for 30 minutes per day, 5 days a week, throughout the 3-month study period. To improve patient adherence to exercise, patients will be provided with an exercise diary.
Numerical Rating Scale at Third Month after the last ozone injection
The Numerical Rating Scale is an 11-point segment scale used to evaluate the severity of knee joint pain. Scores range from 0 to 10, where 0 indicates "no pain" and 10 indicates "the worst possible pain."
Time frame: Baseline, Week 2 (immediately after the 3rd injection session), 1 month after the last ozone injection, and 3 months after the last ozone injection.
Knee-specific symptoms and physical function-WOMAC
The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a self-administered questionnaire specific to knee osteoarthritis, consisting of 24 items divided into 3 subscales: Pain (5 items), Stiffness (2 items), and Physical Function (17 items). Total scores range from 0 to 96, with higher scores indicating worse symptoms and greater physical limitation. Lower scores represent better functional improvement.
Time frame: Baseline, Week 2 (immediately after the 3rd injection session), 1 month after the last ozone injection, and 3 months after the last ozone injection.
Osteoarthritis severity and physical disability- Lequesne Algofunctional Index
The Lequesne Index is used to assess the severity of knee osteoarthritis and the level of physical disability. It includes questions regarding pain, maximum walking distance, and daily living activities. The total score ranges from 0 to 24. Higher scores indicate more severe osteoarthritis.
Time frame: Baseline, Week 2 (immediately after the 3rd injection session), 1 month after the last ozone injection, and 3 months after the last ozone injection.
Overall health-related quality of life- EuroQol 5-Dimension (EQ-5D) questionnaire
The EQ-5D questionnaire evaluates general health-related quality of life across 5 dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Scores are converted into an index score ranging from less than 0 to 1. Higher scores indicate a better quality of life.
Time frame: Baseline, Week 2 (immediately after the 3rd injection session), 1 month after the last ozone injection, and 3 months after the last ozone injection.
6-Minute Walk Test (6MWT)
The 6MWT is an objective clinical test used to assess functional capacity and dynamic mobility. Patients are instructed to walk as far as possible along a straight corridor in 6 minutes. The total distance covered is measured in meters. An increase in the walking distance indicates an improvement in functional mobility.
Time frame: Baseline, Week 2 (immediately after the 3rd injection session), 1 month after the last ozone injection, and 3 months after the last ozone injection.
Timed Up and Go (TUG) Test
The TUG test is used to evaluate dynamic balance, mobility, and fall risk. Patients are timed as they rise from a standard chair, walk 3 meters, turn around, walk back to the chair, and sit down. The outcome is recorded in seconds. Shorter completion times represent better balance and mobility.
Time frame: Baseline, Week 2 (immediately after the 3rd injection session), 1 month after the last ozone injection, and 3 months after the last ozone injection.
Started Nov 2025 (actual). Primary completion is estimated for Nov 2026, 12 months after the start.
Of 1,111 non-industry interventional studies with no phase under Osteoarthritis, Knee, half reached primary completion within 18 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 36. This study's planned 12 months is below that.
Counting every sponsor, half of 1,251 studies reached it within 18 months; a quarter within 8 and three quarters within 36.
How these figures are worked out, and which studies are left out of them.
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