Osteoarthritis, KneeNCT07881445
Subchondral Drilling Diameter During CARTISTEM Implantation for Knee Cartilage Defects
A study testing 2-mm subchondral drilling and Sequential 4-mm and 2-mm subchondral drilling in people with Osteoarthritis, Knee and Articular Cartilage Defects of the Knee, run by Yonsei University at 1 site in South Korea.
Trial summary
This prospective, randomized study at Severance Hospital compares two subchondral drilling techniques during CARTISTEM implantation for symptomatic medial-compartment knee articular cartilage defects. Read more about this study
- Who is it for?
- Ages 19 years and older
- Conditions the study is for
- Osteoarthritis, Knee, Articular Cartilage Defects of the Knee
- What is being tested?
- 2-mm subchondral drilling and Sequential 4-mm and 2-mm subchondral drilling
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteSouth Korea
- Study dates
- 13 Jul 2026to 19 Feb 2029
- 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 19 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 19 years or older.
- Knee pain for at least 3 months despite conservative treatment, including medication or physical therapy.
- Medial-compartment knee arthritis or articular cartilage defects judged to be the main cause of symptoms.
- Imaging-confirmed medial-compartment cartilage defects for which CARTISTEM implantation has been decided.
- Voluntary written informed consent by the participant or legally authorized representative after understanding the study.
Who cannot join
- Surgery for knee cartilage injury within 1 year before screening.
- Ligament instability requiring simultaneous ligament surgery.
- Kellgren-Lawrence grade IV osteoarthritis on weight-bearing anteroposterior knee radiographs.
- Mechanical-axis varus deformity of 5 degrees or greater, unless corrected by simultaneous high tibial osteotomy.
- Autoimmune or inflammatory arthritis, including rheumatoid arthritis.
- Inability to undergo MRI.
Show all 9Show fewer
- Body mass index of 35 kg/m² or greater.
- Inability to adequately understand the study explanation, including illiteracy or a language barrier.
- Age younger than 19 years.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
South Korea1 site, 1 recruiting
- Recruiting
Yonsei University College of Medicine
Seoul
Sung-Hwan Kim, Professor, +82-2-2228-2180, orthohwan@gmail.com
About this study
Official title: Comparative Analysis of Clinical Outcomes According to Subchondral Bone Drilling Diameter in Allogeneic Umbilical Cord Blood-Derived Mesenchymal Stem Cell (Cartistem®) Implantation for Knee Articular Cartilage Defects
This prospective, randomized study at Severance Hospital compares two subchondral drilling techniques during CARTISTEM implantation for symptomatic medial-compartment knee articular cartilage defects. Sixty participants will be allocated 1:1 to drilling with a 2-mm drill alone or sequential drilling with 4-mm and 2-mm drills. CARTISTEM preparation and implantation will be the same in both groups. High tibial osteotomy may be performed when needed to correct alignment.
The primary endpoint is the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation score at 12 months after surgery. The study will assess non-inferiority of the 2-mm technique using a prespecified margin of 10.3 points. Secondary assessments include pain and knee function, MRI cartilage repair and subchondral bone findings, radiographic osteoarthritis and alignment, and second-look arthroscopy in participants undergoing plate removal after high tibial osteotomy.
Read the detailed description
Eligible adults with persistent knee pain and medial-compartment cartilage defects scheduled for CARTISTEM implantation will be recruited at the Department of Orthopedic Surgery, Severance Hospital. Computer-generated randomization will allocate 60 participants equally between two parallel groups. Recruitment is planned for one year, follow-up for 12 months after surgery, and the overall research period for three years after approval.
The experimental group will undergo subchondral drilling with a 2-mm drill alone. The active comparator group will undergo sequential drilling with 4-mm and 2-mm drills. Both groups will receive allogeneic human umbilical cord blood-derived mesenchymal stem cells mixed with sodium hyaluronate hydrogel and implanted into the drilled holes and over the cartilage defect. High tibial osteotomy may accompany implantation when clinically indicated.
Baseline assessments include demographics, clinical scores, standing knee radiographs, lower-limb alignment radiographs, and MRI. Arthroscopy at surgery will document lesion location, size, and ICRS lesion grade. IKDC, pain VAS, Lysholm, and KOOS assessments are scheduled at 3, 6, and 12 months. Radiographic assessments are scheduled at 6 and 12 months, and MRI at 12 months. Second-look arthroscopy is limited to participants undergoing plate removal after concomitant high tibial osteotomy.
Non-inferiority will be assessed using the between-group difference in the 12-month IKDC score and its 95% confidence interval, with a 10.3-point margin. Adverse events will be assessed at postoperative visits.
Participants are masked to the allocated drilling technique. Assessors of secondary imaging, arthroscopic, and histological outcomes are masked to allocation and evaluate coded participant information. The operating surgeon is aware of allocation. No biopsy or genetic analysis is planned.
Research funding: MEDIPOST; total study budget: KRW 60,000,000.
- Being tested
- 2-mm subchondral drilling, Sequential 4-mm and 2-mm subchondral drilling
- Keywords
- CARTISTEM, allogeneic umbilical cord blood-derived mesenchymal stem cells, subchondral drilling, cartilage repair, knee osteoarthritis, IKDC, MOCART 2.0, high tibial osteotomy
- Medical subject headings
- Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
2-mm subchondral drillingProcedure or surgery
Also called 2-mm subchondral drilling with CARTISTEM implantation, Small-diameter subchondral drilling, CARTISTEM implantation
Under general or spinal anesthesia, the cartilage defect is exposed and prepared. Subchondral holes are drilled with a 2-mm drill alone. Allogeneic umbilical cord blood-derived mesenchymal stem cells are mixed with sodium hyaluronate hydrogel, placed into the drilled holes, and applied over the defect. The same cell product preparation is used in both arms. High tibial osteotomy may precede implantation when indicated.
Sequential 4-mm and 2-mm subchondral drillingProcedure or surgery
Also called Sequential 4-mm and 2-mm subchondral drilling with CARTISTEM implantation, Combined-diameter subchondral drilling; CARTISTEM implantation.
Under general or spinal anesthesia, the cartilage defect is exposed and prepared. Subchondral holes are made using sequential 4-mm and 2-mm drilling. The same allogeneic umbilical cord blood-derived mesenchymal stem cell and sodium hyaluronate hydrogel preparation is implanted into the holes and over the defect. High tibial osteotomy may precede implantation when indicated.
| Study group | Role | What they receive |
|---|---|---|
| 2-mm subchondral drilling | Experimental | Subchondral drilling with a 2-mm drill alone, followed by CARTISTEM implantation. High tibial osteotomy may be performed when needed for alignment correction. Receives: Procedure: 2-mm subchondral drilling |
| Sequential 4-mm and 2-mm subchondral drilling | Active comparator | Sequential subchondral drilling with 4-mm and 2-mm drills, followed by the same CARTISTEM preparation and implantation. High tibial osteotomy may be performed when needed. Receives: Procedure: Sequential 4-mm and 2-mm subchondral drilling |
What is being measured
The primary outcome is the main question the study is designed to answer.
IKDC Subjective Knee Evaluation score at 12 months after surgery
The IKDC Subjective Knee Evaluation score assesses participant-reported knee symptoms and function on a 0-100 scale. Higher scores indicate better function and fewer symptoms. The primary non-inferiority comparison uses the 12-month between-group difference and its 95% confidence interval, with a prespecified margin of 10.3 points.
Measured: 12 months after surgery. Additional protocol measurements occur at 3 and 6 months.
Secondary outcomes (10)
Pain visual analog scale
Knee pain assessed using a 10-cm visual analog scale (VAS), recorded from 0 to 10: 0 = no pain; 10 = worst imaginable pain. Higher scores indicate greater pain. Scores and changes from baseline are assessed.
Measured: Baseline and 3, 6, and 12 months after surgery
Lysholm knee score
Patient-reported knee symptoms and function measured using the Lysholm knee score, ranging from 0 to 100; higher scores indicate better knee function.
Measured: Baseline and 3, 6, and 12 months after surgery
Knee injury and Osteoarthritis Outcome Score (KOOS)
The original 42-item Knee injury and Osteoarthritis Outcome Score (KOOS) assesses pain, symptoms, activities of daily living, sport/recreation, and knee-related quality of life. Each of the five subscales is scored separately from 0 to 100; higher scores indicate fewer symptoms and better function.
Measured: Baseline and 3, 6, and 12 months after surgery
MOCART 2.0 knee score
MRI assessment of cartilage repair using the MOCART 2.0 knee score, ranging from 0 to 100; higher scores indicate more favorable repair tissue morphology.
Measured: 12 months after surgery
Subchondral edema assessment
Subchondral edema assessed on MRI using the relevant MOCART 2.0 subscale.
Measured: 12 months after surgery
Presence of subchondral cysts
Presence or absence of subchondral cysts on MRI.
Measured: 12 months after surgery
Presence of subchondral insufficiency fracture
Presence or absence of subchondral insufficiency fracture on MRI.
Measured: 12 months after surgery
ICRS Cartilage Repair Assessment
ICRS Cartilage Repair Assessment at second-look arthroscopy during plate removal in participants with concomitant high tibial osteotomy. Defect filling, integration with adjacent cartilage, and macroscopic appearance are each scored from 0 to 4 and summed to a total of 0 to 12; higher scores indicate better cartilage repair. Overall repair is classified from Grade I (normal) to Grade IV (severely abnormal).
Measured: At second-look arthroscopy during plate removal, planned at 12 months
Kellgren-Lawrence grade
Radiographic osteoarthritis assessed using the Kellgren-Lawrence grade, ranging from 0 to 4; higher grades indicate more severe osteoarthritis.
Measured: Baseline and 6 and 12 months after surgery
Hip-knee-ankle angle
Lower-limb alignment measured as the hip-knee-ankle angle, in degrees, on standing full-length radiographs.
Measured: Baseline and 6 and 12 months after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Oct 2026
- Study start13 Jul 2026
- Primary completion31 Jul 2028 (estimated)
- Study completion19 Feb 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Osteoarthritis, KneeStudies of the same condition, open and under way.
- More trials run by Yonsei 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
- Model description
- Two parallel groups with 1:1 random allocation to 2-mm drilling alone or sequential 4-mm and 2-mm drilling during CARTISTEM implantation.
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Yonsei University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07881445
- Sponsor's protocol ID
- 4-2025-1789
- Status last verified
- Oct 2026
- First submitted
- 11 Oct 2026
- Last updated
- 19 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: The plan to share individual participant data with other researchers has not yet been determined.
Study at a glance
From the registry record, last updated by the sponsor on 19 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparative Analysis of Clinical Outcomes According to Subchondral Bone Drilling Diameter in Allogeneic Umbilical Cord Blood-Derived Mesenchymal Stem Cell (Cartistem®) Implantation for Knee Articular Cartilage Defects
- ClinicalTrials.gov ID
- NCT07881445
- Acronym / sponsor ID
- 4-2025-1789
- Keywords
- CARTISTEM, allogeneic umbilical cord blood-derived mesenchymal stem cells, subchondral drilling, cartilage repair, knee osteoarthritis, IKDC, MOCART 2.0, high tibial osteotomy
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Yonsei UniversityUniversity, hospital or other
- Study start
- 13 Jul 2026 (actual)
- Primary completion
- 31 Jul 2028 (estimated)
- Study completion
- 19 Feb 2029 (estimated)
- First posted
- 19 Oct 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.
This prospective, randomized study at Severance Hospital compares two subchondral drilling techniques during CARTISTEM implantation for symptomatic medial-compartment knee articular cartilage defects. Sixty participants will be allocated 1:1 to drilling with a 2-mm drill alone or sequential drilling with 4-mm and 2-mm drills. CARTISTEM preparation and implantation will be the same in both groups. High tibial osteotomy may be performed when needed to correct alignment.
The primary endpoint is the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation score at 12 months after surgery. The study will assess non-inferiority of the 2-mm technique using a prespecified margin of 10.3 points. Secondary assessments include pain and knee function, MRI cartilage repair and subchondral bone findings, radiographic osteoarthritis and alignment, and second-look arthroscopy in participants undergoing plate removal after high tibial osteotomy.
Detailed description
Eligible adults with persistent knee pain and medial-compartment cartilage defects scheduled for CARTISTEM implantation will be recruited at the Department of Orthopedic Surgery, Severance Hospital. Computer-generated randomization will allocate 60 participants equally between two parallel groups. Recruitment is planned for one year, follow-up for 12 months after surgery, and the overall research period for three years after approval.
The experimental group will undergo subchondral drilling with a 2-mm drill alone. The active comparator group will undergo sequential drilling with 4-mm and 2-mm drills. Both groups will receive allogeneic human umbilical cord blood-derived mesenchymal stem cells mixed with sodium hyaluronate hydrogel and implanted into the drilled holes and over the cartilage defect. High tibial osteotomy may accompany implantation when clinically indicated.
Baseline assessments include demographics, clinical scores, standing knee radiographs, lower-limb alignment radiographs, and MRI. Arthroscopy at surgery will document lesion location, size, and ICRS lesion grade. IKDC, pain VAS, Lysholm, and KOOS assessments are scheduled at 3, 6, and 12 months. Radiographic assessments are scheduled at 6 and 12 months, and MRI at 12 months. Second-look arthroscopy is limited to participants undergoing plate removal after concomitant high tibial osteotomy.
Non-inferiority will be assessed using the between-group difference in the 12-month IKDC score and its 95% confidence interval, with a 10.3-point margin. Adverse events will be assessed at postoperative visits.
Participants are masked to the allocated drilling technique. Assessors of secondary imaging, arthroscopic, and histological outcomes are masked to allocation and evaluate coded participant information. The operating surgeon is aware of allocation. No biopsy or genetic analysis is planned.
Research funding: MEDIPOST; total study budget: KRW 60,000,000.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- Two parallel groups with 1:1 random allocation to 2-mm drilling alone or sequential 4-mm and 2-mm drilling during CARTISTEM implantation.
| Arm | Type | Receives |
|---|---|---|
| 2-mm subchondral drilling | Experimental | Procedure: 2-mm subchondral drillingSubchondral drilling with a 2-mm drill alone, followed by CARTISTEM implantation. High tibial osteotomy may be performed when needed for alignment correction. |
| Sequential 4-mm and 2-mm subchondral drilling | Active comparator | Procedure: Sequential 4-mm and 2-mm subchondral drillingSequential subchondral drilling with 4-mm and 2-mm drills, followed by the same CARTISTEM preparation and implantation. High tibial osteotomy may be performed when needed. |
Who may qualify
- Ages
- 19 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Age 19 years or older.
- Knee pain for at least 3 months despite conservative treatment, including medication or physical therapy.
- Medial-compartment knee arthritis or articular cartilage defects judged to be the main cause of symptoms.
- Imaging-confirmed medial-compartment cartilage defects for which CARTISTEM implantation has been decided.
- Voluntary written informed consent by the participant or legally authorized representative after understanding the study.
Key exclusion criteria (9 listed)
- Surgery for knee cartilage injury within 1 year before screening.
- Ligament instability requiring simultaneous ligament surgery.
- Kellgren-Lawrence grade IV osteoarthritis on weight-bearing anteroposterior knee radiographs.
- Mechanical-axis varus deformity of 5 degrees or greater, unless corrected by simultaneous high tibial osteotomy.
- Autoimmune or inflammatory arthritis, including rheumatoid arthritis.
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 |
|---|---|---|
| 2-mm subchondral drillingAlso: 2-mm subchondral drilling with CARTISTEM implantation, Small-diameter subchondral drilling, CARTISTEM implantationUnder general or spinal anesthesia, the cartilage defect is exposed and prepared. Subchondral holes are drilled with a 2-mm drill alone. Allogeneic umbilical cord blood-derived mesenchymal stem cells are mixed with sodium hyaluronate hydrogel, placed into the drilled holes, and applied over the defect. The same cell product preparation is used in both arms. High tibial osteotomy may precede implantation when indicated. | Procedure or surgery | 2-mm subchondral drilling |
| Sequential 4-mm and 2-mm subchondral drillingAlso: Sequential 4-mm and 2-mm subchondral drilling with CARTISTEM implantation, Combined-diameter subchondral drilling; CARTISTEM implantation.Under general or spinal anesthesia, the cartilage defect is exposed and prepared. Subchondral holes are made using sequential 4-mm and 2-mm drilling. The same allogeneic umbilical cord blood-derived mesenchymal stem cell and sodium hyaluronate hydrogel preparation is implanted into the holes and over the defect. High tibial osteotomy may precede implantation when indicated. | Procedure or surgery | Sequential 4-mm and 2-mm subchondral drilling |
Primary outcome
IKDC Subjective Knee Evaluation score at 12 months after surgery
Time frame: 12 months after surgery. Additional protocol measurements occur at 3 and 6 months.
The IKDC Subjective Knee Evaluation score assesses participant-reported knee symptoms and function on a 0-100 scale. Higher scores indicate better function and fewer symptoms. The primary non-inferiority comparison uses the 12-month between-group difference and its 95% confidence interval, with a prespecified margin of 10.3 points.
10 secondary outcomes
Pain visual analog scale
Time frame: Baseline and 3, 6, and 12 months after surgery
Lysholm knee score
Time frame: Baseline and 3, 6, and 12 months after surgery
Knee injury and Osteoarthritis Outcome Score (KOOS)
Time frame: Baseline and 3, 6, and 12 months after surgery
MOCART 2.0 knee score
Time frame: 12 months after surgery
Subchondral edema assessment
Time frame: 12 months after surgery
Presence of subchondral cysts
Time frame: 12 months after surgery
Presence of subchondral insufficiency fracture
Time frame: 12 months after surgery
ICRS Cartilage Repair Assessment
Time frame: At second-look arthroscopy during plate removal, planned at 12 months
Kellgren-Lawrence grade
Time frame: Baseline and 6 and 12 months after surgery
Hip-knee-ankle angle
Time frame: Baseline and 6 and 12 months after surgery
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 19 Oct 2026.
- Individual participant dataSharing planned: Undecided. The plan to share individual participant data with other researchers has not yet been determined.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing 2-mm subchondral drilling and Sequential 4-mm and 2-mm subchondral drilling in people with Osteoarthritis, Knee and Articular Cartilage Defects of the Knee, run by Yonsei University at 1 site in South Korea.
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 9 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 19 Oct 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 South Korea. 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 Sung-Hwan Kim, Professor (+82-2-2228-2180, orthohwan@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
IKDC Subjective Knee Evaluation score at 12 months after surgery (time frame: 12 months after surgery. Additional protocol measurements occur at 3 and 6 months.). 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 19 Oct 2026.