Subchondroplasty® Knee RCT (PRESERVE Knee)

April 21, 2026 updated by: Zimmer Biomet

A Randomized Controlled Trial of the Subchondroplasty® Procedure With Arthroscopy Versus Arthroscopy Alone for Treatment of Bone Marrow Lesions in the Knee

This is a multi-center, prospective, single-blinded, two-arm study, randomized to include approximately 134 subjects treated with Subchondroplasty (SCP) + Arthroscopy and 67 subjects with arthroscopy alone.

The primary objective of this study is to demonstrate superiority of Subchondroplasty with arthroscopy compared to arthroscopy alone for treatment of Bone Marrow Lesions (BMLs) in the knee.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a multicenter, prospective, single-blinded, two-arm, randomized study. Enrolled subjects will have a single Bone Marrow Lesion of the tibia, single BML of the femur, or adjoining Bone Marrow Lesions of tibia and femur. Subjects will also be surgical candidates for knee arthroscopy due to mechanical symptoms, meniscus tear, loose body and/or synovitis.

A stratified blocked randomization will be used to assign subjects to either Subchondroplasty with arthroscopy or to arthroscopy alone in a 2:1 ratio. Individual sets of blocks will be determined within study site and lesion polarity status (unipolar vs. bipolar).

Subjects will be enrolled within 60 days prior to surgery and take part in follow-up visits for two years following surgery. A preoperative visit will occur at the time of enrollment. Follow-up visits were to initially occur at the study site at 6 weeks, 3 months, 6 months, 12 months, and 24 months post-surgery. Telephone follow-up interviews to be be performed at 9 and 18 months post-surgery. Target enrollment was 201 subjects, to include 134 subjects in the treatment group (Subchondroplasty + Arthroscopy) and 67 subjects in the control group (Arthroscopy alone).

As of October 2020, follow-up has been amended to be completed remotely, where all visits can be performed electronically and/or via telephone.

Subjects will complete the study at the 24 month follow-up visit. For the purposes of this protocol, a revision will be defined as any partial or total joint arthroplasty or any bone fixation, bone grafting or bone substitute procedure in the same compartment in the study knee.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
131

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Hamilton, Ontario, Canada, L8N4A6
        • Research St. Joseph's - Hamilton
  • United States
    • California
      • Encinitas, California, United States, 92024
        • CORE Orthopaedic Medical Center
      • Loma Linda, California, United States, 92354
        • Loma Linda University Health System
      • Stanford, California, United States, 94305
        • Stanford University
    • Florida
      • Tampa, Florida, United States, 33637
        • Foundation for Orthopaedic Research and Education
    • Georgia
      • Atlanta, Georgia, United States, 30329
        • Emory University
    • Illinois
      • Chicago, Illinois, United States, 60612-3833
        • Rush University Medical Center
    • Maryland
      • Timonium, Maryland, United States, 21093
        • Medstar Health Research Institute
    • New Mexico
      • Albuquerque, New Mexico, United States, 87106
        • New Mexico Orthopaedic Fellowship Foundation
    • Ohio
      • Columbus, Ohio, United States, 43202
        • The Ohio State University
    • South Carolina
      • Greenville, South Carolina, United States, 29615
        • Hawkins Foundation
    • Texas
      • Austin, Texas, United States, 78745
        • Orthopedic Associates of Central Texas
    • Virginia
      • Charlottesville, Virginia, United States, 22903
        • University of Virginia

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

30 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Candidates must meet ALL of the following:

    1. Voluntary signature of the Institutional Review Board/Research Ethics Board approved Informed Consent,
    2. Male or female subjects between the ages of 30 to 75 years,
    3. Body Mass Index ≤ 40 (BMI=kg/m2),
    4. Has experienced pain in study knee for at least 3 months,
    5. Kellgren-Lawrence grade 1-3 Osteoarthritis, as reviewed on preoperative XR imaging, in the study knee,
    6. BML is confirmed on T2 weighted or Proton Density MR Imaging by presence of white signal,
    7. Single BML of tibia, single BML of femur, or adjoining BML's of tibia & femur, in the same compartment, extending to the articular surface of the joint,
    8. Surgical candidate for knee arthroscopy due to mechanical symptoms, meniscus tear, loose body and/or synovitis,
    9. Must record a response, at the preoperative study visit, of moderate to extreme pain for any one of the KOOS Pain Scale questions, P2 through P9,
    10. Index knee alignment is defined radiographically as one of the following: Neutral, ≤ 6° mechanical varus, or ≤ 6° mechanical valgus,
    11. Ligaments in the study knee are stable,
    12. The contralateral (non-study) knee is stable and functional,

    13. Is refractory to conservative non-surgical management

      1. having failed 2 or more of the following: hyaluronic acid injection, corticosteroid injection, NSAIDs, physical therapy, bracing, activity modification, or minimal surgical intervention (e.g., arthroscopy, debridement/chondroplasty, and/or loose body removal)
      2. and is ≥ 3 months from the start of treatment,
    14. Must be physically and mentally willing and able, in the Investigator's opinion at the time of enrollment, to be compliant with the protocol - including all follow-up visits, survey completion, weight-bearing restrictions, and post-operative rehabilitation.

Exclusion Criteria:

  • Candidates will be excluded if they meet ANY of the following:

    1. BML caused by acute trauma less than 3 months prior to enrollment,

    2. Clinical and/or radiographic disease diagnosis of the index knee that includes any of the following:

      1. Kellgren-Lawrence Grade 4 Osteoarthritis with complete loss of joint space (bone-on-bone) or subchondral bone collapse,
      2. Rheumatoid arthritis, or history of septic or reactive arthritis,
      3. Gout or a history of gout or pseudogout in the affected knee,
      4. Has more than two clinically relevant BMLs in the index knee,
      5. Osteochondritis dissecans of the knee with significant bone loss,
      6. Collapse of subchondral bone,
      7. Clinically relevant BML located at ACL/PCL insertion,
      8. MRI evidence of frank ligament instability,
    3. Passive knee flexion < 110° or flexion contracture >30°,
    4. History of systemic diseases which could contribute to secondary arthropathies (e.g., sickle cell disease, hemochromatosis, or autoimmune disease),
    5. Has a neuromuscular, neurosensory, or musculoskeletal deficiency that limits the ability to perform objective functional assessment of either knee,
    6. If diabetic, blood glucose over 200 mg/dL at time of enrollment,
    7. Current daily tobacco or high nicotine product user or < 3 months from nicotine cessation,
    8. Presents a high surgical risk due to unstable cardiac and/or pulmonary disease,
    9. Has HIV or other immunodeficient state including subjects on immunosuppressant therapies, or has significant illness (metastasis of any type) that decreases the probability of survival to the 2 year endpoint,
    10. Is at substantial risk for the need of organ transplantation, such as renal insufficiency,
    11. Is pregnant or breast-feeding at the time of surgery,
    12. Has a history of any invasive malignancy (except non-melanoma skin cancer), unless treated with curative intent and with no clinical signs or symptoms of the malignancy for 5 years,
    13. Has primary bone tumor in the knee area,
    14. Anticipates having a lower extremity surgery other than the investigational surgery during the course of the study,
    15. Is participating concurrently in another clinical trial, or has participated in a clinical trial within 30 days of surgery,
    16. Is receiving prescription pain medication other than NSAIDs or acetaminophen for conditions unrelated to the index knee condition, chronic use of anticoagulants, or taking corticosteroids,
    17. Active joint infection or history of chronic joint infection at the surgical site,
    18. Prior total meniscectomy of index knee,
    19. Has primarily patellofemoral symptoms,
    20. Is indicated for concomitant procedures (i.e., microfracture, subchondral drilling, cartilage allograft, ligament or tendon repair, distal realignment/osteotomy, root repair) in the index knee, with the exception of incidental loose body removal, debridement, synovectomy, osteophyte removal in locations other than adjacent to BMLs, and/or partial meniscectomy,
    21. Has contraindications for Magnetic Resonance Imaging (MRI),
    22. Is receiving worker's compensation or is currently involved in litigation relating to the index knee,
    23. Has a history of substance abuse.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Subchondroplasty with Arthroscopy
After randomization to the study group, subjects assigned to the Subchondroplasty + Arthroscopy group will undergo the Subchondroplasty portion of the procedure before or after the Arthroscopy portion per the surgeon's discretion. All operative procedures are to be performed under aseptic conditions according to the institution's standards.
Procedure: Subchondroplasty with Arthroscopy
The Subchondroplasty® (SCP®) Procedure targets and fills bone defects with AccuFill® Bone Substitute Material utilizing an arthroscopic / percutaneous approach. Using intraoperative fluoroscopy, the bone defect is localized relative to MRI findings The appropriate AccuPort® Delivery Cannula is drilled to the bone defect. AccuFill® Bone Substitute Material is then injected into the subchondral bone defect. The calcium phosphate (CaP) fills the edematous void and hardens within the Bone Marrow Lesion. The CaP is resorbed over time and replaced with new bone during the healing process.
Sham Comparator: Arthroscopy Alone

After randomization, subjects assigned to the Arthroscopy control group will undergo arthroscopy of the study knee with one or more of the following procedures:

  • Partial meniscectomy
  • Lavage
  • Debridement
  • Loose body removal
  • Synovectomy
  • Removal of osteophytes in the notch or locations other than those adjacent to BML(s)

Superficial skin incision(s) should be created at the typical AccuPort® access point(s) as if the subject had undergone Subchondroplasty. The incisions should be closed in the typical fashion.
Procedure: Arthroscopy Alone
An endoscopic examination, therapy and surgery of the knee joint.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Composite Clinical Success
Time Frame: Superiority will be statistically tested at month 12 at p<0.01

The primary objective of this study is to determine whether Subchondroplasty with arthroscopy is superior to arthroscopy alone for treatment of bone marrow lesions in the knee.

Superiority will be evaluated in terms of Composite Clinical Success (CCS) requiring freedom from subsequent secondary surgical intervention (SSSI) and among those free from SSSI, a clinically meaningful reduction in self-reported pain based on a validated measure of subject-reported pain (improvement in KOOS (Knee Injury and Osteoarthritis Outcome Score) pain of at least 10 points at 12 months).

For the purpose of this study, SSSI will include any partial or total joint arthroplasty or any bone grafting or bone substitute procedure in the study knee.
Superiority will be statistically tested at month 12 at p<0.01

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change From Baseline KOOS Subscale Scores at 12 Months
Time Frame: 12 months post-surgery
Comparison of mean change in KOOS subscale scores (Pain, Activities of Daily Living), Symptoms, Sports and Recreation, Quality of Life). Each subscale is scored from 0 to 100 on a worst to best scale.
12 months post-surgery
Change From Baseline Numeric Pain Score at 12 Months
Time Frame: 12 months post-surgery
Comparison of mean Numeric Pain Score (NPS). The NPS is scored from 0 to 10 where 0 indicates no pain; 5 indicates moderate pain; and 10 indicates the worst pain.
12 months post-surgery
Change From Baseline EQ-5D Index Score at 12 Months
Time Frame: 12 months post-surgery
Comparison of mean EQ-5D Index score
12 months post-surgery
Global Satisfaction Score at 6-Weeks
Time Frame: 6-weeks post-surgery
Patient satisfaction with knee procedure rated on a 0-10 scale, where 0 = totally dissatisfied and 10 = extremely satisfied.
6-weeks post-surgery
Change From Baseline KOOS Subscale Scores at 24 Months
Time Frame: 24 months post-surgery
Comparison of mean change in KOOS subscale scores (Pain, Activities of Daily Living), Symptoms, Sports and Recreation, Quality of Life). Each subscale is scored from 0 to 100 on a worst to best scale.
24 months post-surgery
Change From Baseline Numeric Pain Score at 24 Months
Time Frame: 24 months post-surgery
Comparison of mean Numeric Pain Score (NPS). The NPS is scored from 0 to 10 where 0 indicates no pain; 5 indicates moderate pain; and 10 indicates the worst pain.
24 months post-surgery
Change From Baseline EQ-5D Overall Health Score at 12 Months
Time Frame: 12 months post-surgery
Comparison of mean EQ-5D Overall Health score using the EQ Visual Analog Scale (VAS), ranging from 0 (worst imaginable health) to 100 (best imaginable health).
12 months post-surgery
Change From Baseline EQ-5D Overall Health Score at 24 Months
Time Frame: 24 months post-surgery
Comparison of mean EQ-5D Overall Health score using the EQ Visual Analog Scale (VAS), ranging from 0 (worst imaginable health) to 100 (best imaginable health).
24 months post-surgery
Global Satisfaction Score at 3 Months
Time Frame: 3 Months post-surgery
Patient satisfaction with knee procedure rated on a 0-10 scale, where 0 = totally dissatisfied and 10 = extremely satisfied.
3 Months post-surgery
Global Satisfaction Score at 6 Months
Time Frame: 6 months post-surgery
Patient satisfaction with knee procedure rated on a 0-10 scale, where 0 = totally dissatisfied and 10 = extremely satisfied.
6 months post-surgery
Global Satisfaction Score at 12 Months
Time Frame: 12 months post-surgery
Patient satisfaction with knee procedure rated on a 0-10 scale, where 0 = totally dissatisfied and 10 = extremely satisfied.
12 months post-surgery
Global Satisfaction Score at 24 Months
Time Frame: 24 months post-surgery
Patient satisfaction with knee procedure rated on a 0-10 scale, where 0 = totally dissatisfied and 10 = extremely satisfied.
24 months post-surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Zimmer Biomet

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Medical Metrics Diagnostics, Inc
MedNet Solutions

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Jason Dragoo, MD, University of Colorado, Denver

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 29, 2017

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 23, 2023

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 23, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 27, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 7, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 13, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 14, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 21, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • KC.CR.I.AM.16.1

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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