An interventional study of Standard Postoperative Rehabilitation Protocol and Oral Chondroitin Sulfate (Flextrum) in Meniscus Lesion, Knee Injuries and Medial Meniscus Tear, sponsored by Collegium Medicum w Bydgoszczy. Completed at 2 sites in Poland. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-03-17.
Sponsored by Collegium Medicum w Bydgoszczy · Not applicable, Interventional, and Treatment
This study evaluates the effectiveness of intra-articular hyaluronic acid (HA) viscosupplementation and oral chondroitin sulfate (CS) supplementation, in combination with standard postoperative rehabilitation, on functional recovery, pain reduction, and quality of life following knee arthroscopy for medial meniscus injury. Knee arthroscopy is commonly performed for meniscal tears, but the extensive joint irrigation during the procedure removes naturally occurring synovial fluid, potentially prolonging recovery. Hyaluronic acid is the main component of synovial fluid and plays crucial roles in joint lubrication, shock absorption, and cartilage protection. This prospective, randomized, three-arm controlled trial will enroll approximately 290 patients undergoing arthroscopy for medial meniscus injury. Participants will be randomized into three groups: (1) standard rehabilitation alone (Control), (2) rehabilitation plus oral CS supplementation (1200mg CS and 40mg Vitamin C daily for 12 weeks), or (3) rehabilitation plus two intra-articular HA injections (Biolevox™ HA 2.2%, administered at 2 weeks and 6 weeks post-arthroscopy). The primary outcome is knee function assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) at 12 weeks. Secondary outcomes include quality of life (WHOQoL-BREF questionnaire) and safety assessments. The study hypothesis is that viscosupplementation with medium molecular weight HA will result in superior functional outcomes compared with oral supplementation or standard rehabilitation alone.
Knee arthroscopy is the most commonly performed orthopedic procedure. Although it offers advantages over open surgery, including reduced postoperative pain and faster recovery, the procedure inevitably involves extensive joint irrigation which removes naturally occurring synovial fluid. Synovial fluid plays a crucial role in joint lubrication and shock absorption. Its reduction following arthroscopy increases friction between articular surfaces, intensifying pain and potentially prolonging rehabilitation. Recovery typically requires 4-6 weeks, during which patients may experience persistent pain and limited joint function. Viscosupplementation with hyaluronic acid (HA) has emerged as a promising approach to addressing post-arthroscopic joint dysfunction. HA is the main non-protein component of synovial fluid, forming a protective layer on articular cartilage, reducing friction and helping maintain tissue resistance to compressive forces. Beyond mechanical effects, HA provides biological benefits including stimulation of endogenous HA synthesis, reduction of proteoglycan loss, and protection of chondrocytes from apoptosis. Oral chondroitin sulfate (CS) supplementation has also been proposed as an adjunctive therapy, with proposed mechanisms including support for cartilage homeostasis through stimulation of proteoglycan and collagen synthesis.
267 studies on the registry are indexed under Knee Injuries; 59 are open to participants now.
This study's enrollment of 290 is above the median of 49 across 178 interventional studies indexed under Knee Injuries.
Browse Knee Injuries studies →Collegium Medicum w Bydgoszczy is the lead sponsor of 26 studies on the registry; 4 are open to participants now.
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Age 18-65 years at time of enrollment
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.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
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.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
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.
Participants receive standard postoperative rehabilitation protocol over 12 weeks consisting of four sequential phases: Phase I (weeks 0-3) - joint protection, partial weight-bearing with brace and crutches, swelling management, patellar mobilization, knee ROM exercises 0-90°, quadriceps isometric exercises, straight-leg raises; Phase II (weeks 3-6) - partial weight-bearing continuation, progressive ROM restoration using stationary bicycle, calf strengthening, balance training; Phase III (weeks 6-9) - full weight-bearing progression once adequate quadriceps control achieved, progressive strengthening exercises (partial squats 0-60° knee flexion, hamstring strengthening), cardiovascular conditioning; Phase IV (weeks 9-12) - advanced functional strengthening including lunges, step-based exercises, single-leg progressions.
Behavioral: Standard Postoperative Rehabilitation Protocol
Participants receive standard postoperative rehabilitation protocol (identical to Control arm) PLUS oral chondroitin sulfate supplementation (Flextrum: 1200mg chondroitin sulfate and 40mg Vitamin C) taken daily for 12 weeks.
Behavioral: Standard Postoperative Rehabilitation Protocol · Dietary Supplement: Oral Chondroitin Sulfate (Flextrum)
Participants receive standard postoperative rehabilitation protocol (identical to Control arm) PLUS two intra-articular hyaluronic acid injections (Biolevox™ HA 2.2%, concentration 22mg/mL, volume 2mL, molecular weight 1400-2400 kDa) administered at 2 weeks and 6 weeks post-arthroscopy. Injections are performed under real-time ultrasound guidance using a lateral mid-patellar portal with the knee in full extension, administered by a single certified orthopedic physician.
Behavioral: Standard Postoperative Rehabilitation Protocol · Device: ntra-articular Hyaluronic Acid Injection (Biolevox)
Evidence-based 12-week progressive rehabilitation program consisting of four phases progressing from joint protection through functional strengthening, including partial/full weight-bearing progression, ROM exercises, quadriceps/hamstring strengthening, balance training, and functional exercises. Arm Group Labels: Control - Standard Rehabilitation; Oral Chondroitin Sulfate Supplementation; Intra-articular Hyaluronic Acid Viscosupplementation
Flextrum tablets containing 1200mg chondroitin sulfate and 40mg Vitamin C taken orally once daily for 12 weeks starting immediately post-arthroscopy. Arm Group Labels: Oral Chondroitin Sulfate Supplementation
Biolevox™ HA 2.2% (concentration 22mg/mL, volume 2mL per injection, molecular weight 1400-2400 kDa, bacterial fermentation origin) administered via ultrasound-guided intra-articular injection using lateral mid-patellar approach with knee in full extension. Two injections total: first at 2 weeks post-arthroscopy and second at 6 weeks post-arthroscopy. Manufacturer: Biovico Sp. z o.o., Gdynia, Poland Arm Group Labels: Intra-articular Hyaluronic Acid Viscosupplementation
Change in Knee Injury and Osteoarthritis Outcome Score (KOOS) Total Score
The KOOS is a validated 42-item patient-reported outcome measure evaluating five domains: Pain (9 items), Other Symptoms (7 items), Function in Daily Living (17 items), Function in Sport and Recreation (5 items), and Knee-related Quality of Life (4 items). Each item is scored on a 0-4 Likert scale. Scores are transformed to 0-100 scale, where 0 represents extreme knee problems, and 100 represents no knee problems. The KOOS Total Score is calculated as the average of all five domain scores. Higher scores indicate better outcomes.
Time frame: Baseline (pre-surgery) and 12 weeks post-arthroscopy
Change in KOOS Pain Subscale Score
The KOOS Pain subscale consists of 9 items assessing pain frequency and severity during various activities. Scores range from 0 (extreme pain) to 100 (no pain). Higher scores indicate less pain and better outcomes.
Time frame: Baseline (pre-surgery) and 12 weeks post-arthroscopy
Change in World Health Organization Quality of Life-BREF (WHOQoL-BREF) - Physical Health Domain
The WHOQoL-BREF is a 26-item questionnaire evaluating health-related quality of life. The Physical Health domain assesses activities of daily living, dependence on medications or medical aids, energy and fatigue, mobility, pain and discomfort, sleep and rest, and work capacity. Domain scores are transformed to a 0-100 scale, where higher scores indicate better quality of life.
Time frame: Baseline (pre-surgery) and 12 weeks post-arthroscopy
Change in WHOQoL-BREF - Social Relationships Domain
The Social Relationships domain of WHOQoL-BREF assesses personal relationships, social support, and sexual activity. Scores transformed to a 0-100 scale, where higher scores indicate better social relationships.
Time frame: Baseline (pre-surgery) and 12 weeks post-arthroscopy
Change in WHOQoL-BREF - Environment Domain
The Environment domain of WHOQoL-BREF assesses financial resources, freedom/physical safety/security, health and social care accessibility and quality, home environment, opportunities for acquiring information and skills, participation in and opportunities for recreation/leisure activities, physical environment, and transport. Scores transformed to 0-100 scale where higher scores indicate better environmental quality of life.
Time frame: Baseline (pre-surgery) and 12 weeks post-arthroscopy
Incidence of Adverse Events
Number of participants experiencing any adverse events, including but not limited to: infection, joint effusion, allergic reactions, injection-site complications, gastrointestinal symptoms, or any other treatment-related adverse effects. Safety will be assessed through participant self-report and clinical examination.
Time frame: Throughout the 12-week study period
Incidence of Serious Adverse Events
Number of participants experiencing serious adverse events (SAEs) defined as any untoward medical occurrence that results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, or is a congenital anomaly/birth defect.
Time frame: Throughout 12-week study period
Plan to share: No
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This study is completed, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Chondroitin
Collegium Medicum w Bydgoszczy