Anterior Cruciate Ligament InjuriesNCT04998656
Werewolf Flow 50 During ACL Reconstruction
A study testing Werewolf FLOW 50 in people with Anterior Cruciate Ligament Injuries and Anterior Cruciate Ligament Rupture, run by University of Colorado, Denver at 3 sites in United States.
Trial summary
The aim of this study is to compare the outcomes, ease of use, and cost of the Werewolf FLOW50 device to the institutional standard of care which is does not include the use of electrocautery devices during anterior cruciate ligament reconstruction (ACLR) surgery in patients 12-18 years of age using a randomized… Read more about this study
- Who is it for?
- Ages 12 to 18 years
- Conditions the study is for
- Anterior Cruciate Ligament Injuries, Anterior Cruciate Ligament Rupture, Anterior Cruciate Ligament Tear
- What is being tested?
- Werewolf FLOW 50
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 182 participants
- Where
- 3 sitesUnited States
- Study dates
- 12 Jul 2021to 2 Nov 2024
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 12 to 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Ages 12-18 (inclusive) at time of surgery
- Scheduled to undergo ACL reconstruction performed at Children's Hospital Colorado or associated network of care site.
Who cannot join
- Underlying congenital or musculoskeletal disorders
- Pregnant females, prisoners, and wards of the state
- Persons deemed incompetent and those who have limited decision-making capacity
Trial locations and contacts
3 sites in 1 country.
United States3 sites
Children's Hospital Colorado, Main Campus
Aurora, Colorado, 80045
Children's Hospital Colorado, North Campus
Broomfield, Colorado, 80023
Children's Hospital Colorado, South Campus
Highlands Ranch, Colorado, 80129
About this study
Official title: Werewolf Flow 50 During ACL Reconstruction: A Randomized Control Trial
The aim of this study is to compare the outcomes, ease of use, and cost of the Werewolf FLOW50 device to the institutional standard of care which is does not include the use of electrocautery devices during anterior cruciate ligament reconstruction (ACLR) surgery in patients 12-18 years of age using a randomized control trial design.
The investigators hypothesize that a lower proportion of participants who undergo ACLR and are randomized to the Werewolf FLOW50 procedure will experience post-operative arthrofibrosis compared to those randomized to standard of care (control group).
Read the detailed description
The investigators foresee minimal risks to participants. The Werewolf FLOW50 is an FDA approved medical device to be used in the knee joint. he surgeon performing each surgery has used both the Werewolf FLOW50 device (according to FDA-approved indications for use) and no electrocautery device as standard of care during ACL reconstruction surgery.
There is minimal risk associated with the subsequent MRI. Participants may experience slight discomfort from the confined space, flashing lights in their eyes, or temporary warmth/reddening of the skin following MRI. Participants will be informed of these risks and discomforts and pregnant participants or those with any metal and/or electronic devices inside their bodies will not receive the MRI.
There is the risk of unintended disclosure of protected health information (PHI) to individuals outside the research team. To mitigate this risk, data points are entered into a password-protected, HIPAA compliant REDCap database accessible to only the PIs and study personnel. Children's Colorado affiliated and approved study personal will have access to all study information collected at all involved study sites. However, other study sites will only have access to the information collected on patients enrolled at their site. We believe this system will contribute to the protection of PHI. The only PHI collected will be visit dates; all participants will be linked to their information via a unique study identifier.
The PI will periodically review the status of this protocol. Any unanticipated problems will be disclosed to COMIRB [Colorado Multiple Institutional Review Board] within five days with a cover letter detailing the assessment and actions to be taken.
- Conditions
- Anterior Cruciate Ligament Injuries, Anterior Cruciate Ligament Rupture, Anterior Cruciate Ligament Tear, Arthrofibrosis of Knee
- Being tested
- Werewolf FLOW 50, Control
- Keywords
- ACL, Anterior Cruciate Ligament, Arthrofibrosis, Knee
- Medical subject headings
- Anterior Cruciate Ligament Injuries
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Werewolf FLOW 50Device
Use of Werewolf FLOW 50 electrocautery device during surgical treatment for ACL injury. This device is often used as standard of care when our other standard of care approach (use of no electrocautery device) is not used.
ControlOther
Also called No Electrocautery Device
Use of no electrocautery device during surgical treatment for ACL injury. This approach is often used as standard of care when our other standard of care approach (use of Werewolf FLOW 50 electrocautery device) is not used.
| Study group | Role | What they receive |
|---|---|---|
| Werewolf FLOW 50 Group | Active comparator | The Werewolf FLOW 50 electrocautery device will be used during surgical treatment for patients assigned to this group. Receives: Device: Werewolf FLOW 50 |
| Control Group | Placebo comparator | No electrocautery device will be used during surgical treatment for patients assigned to this group. Receives: Other: Control |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rates of Post-Operative Arthrofibrosis
Number of participants with post-operative arthrofibrosis
Measured: 1 year post-operative
Secondary outcomes (3)
Range of Motion - Knee
Knee range of motion measured by knee extension and knee flexion, measured in degrees.
Measured: 1 year post-operative
Patient-Reported Outcomes Measurement Information System (PROMIS)
Based on patient reported outcomes (patient surveys) completed pre-operatively and post-operatively, we will compare levels of pain, functionality, and quality of life between the Werewolf FLOW 50 Group and the Control Group.
PROMIS questionnaires are represented as t-scores, where a mean score of 50 with a standard deviation of 10 represents the general population.
PROMIS Pediatric Short Form v2.0 - Mobility measures an individual's self-perceived mobility capabilities, such as getting up from a chair or running. Higher numbers indicate better outcomes.
PROMIS Pediatric Short Form v2.0 - Pain Interference measures how much pain affects daily physical, mental and social activities. Higher numbers indicate worse outcomes.
PROMIS Quality of Life in Neurological Disorders Short Form v1.0 - Lower Extremity Function measures walking, leg mobility and physical tasks for individuals with neurological conditions. Higher numbers indicate better outcomes.
Measured: Data reported below were collected approximately 6-months post-operatively.
Complications
Number of participants with post-operative complications (including arthrofibrosis and injury) between the Werewolf FLOW 50 Group and the Control Group.
Measured: 1 year post-operative
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Aug 2021
- Study start12 Jul 2021
- Primary completion2 Nov 2024
- Study completion2 Nov 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Anterior Cruciate Ligament InjuriesStudies of the same condition, open and under way.
- More trials run by University of Colorado, DenverThe 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 182 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Colorado, Denver
- Sponsor type
- University, hospital or other
- Collaborators
- Smith & Nephew, Inc.
- Responsible party
- Sponsor
- Investigators
- Jay C Albright, MD, Principal investigator, Children's Hospital Colorado
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04998656
- Sponsor's protocol ID
- 20-2720
- Status last verified
- Aug 2026
- First submitted
- 1 Jun 2021
- Last updated
- 14 Sep 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No: IPD will not be shared with individuals outside of the authorized study team.
Study at a glance
From the registry record, last updated by the sponsor on 14 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Werewolf Flow 50 During ACL Reconstruction: A Randomized Control Trial
- ClinicalTrials.gov ID
- NCT04998656
- Acronym / sponsor ID
- 20-2720
- Conditions
- Anterior Cruciate Ligament Injuries, Anterior Cruciate Ligament Rupture, Anterior Cruciate Ligament Tear, Arthrofibrosis of Knee
- Keywords
- ACL, Anterior Cruciate Ligament, Arthrofibrosis, Knee
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 182 participants (actual)
- Lead sponsor
- University of Colorado, DenverUniversity, hospital or other
- Collaborators
- Smith & Nephew, Inc.
- Study start
- 12 Jul 2021 (actual)
- Primary completion
- 2 Nov 2024 (actual)
- Study completion
- 2 Nov 2024 (actual)
- First posted
- 10 Aug 2021 (actual)
- Results
- Posted 14 Sep 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of this study is to compare the outcomes, ease of use, and cost of the Werewolf FLOW50 device to the institutional standard of care which is does not include the use of electrocautery devices during anterior cruciate ligament reconstruction (ACLR) surgery in patients 12-18 years of age using a randomized control trial design.
The investigators hypothesize that a lower proportion of participants who undergo ACLR and are randomized to the Werewolf FLOW50 procedure will experience post-operative arthrofibrosis compared to those randomized to standard of care (control group).
Detailed description
The investigators foresee minimal risks to participants. The Werewolf FLOW50 is an FDA approved medical device to be used in the knee joint. he surgeon performing each surgery has used both the Werewolf FLOW50 device (according to FDA-approved indications for use) and no electrocautery device as standard of care during ACL reconstruction surgery.
There is minimal risk associated with the subsequent MRI. Participants may experience slight discomfort from the confined space, flashing lights in their eyes, or temporary warmth/reddening of the skin following MRI. Participants will be informed of these risks and discomforts and pregnant participants or those with any metal and/or electronic devices inside their bodies will not receive the MRI.
There is the risk of unintended disclosure of protected health information (PHI) to individuals outside the research team. To mitigate this risk, data points are entered into a password-protected, HIPAA compliant REDCap database accessible to only the PIs and study personnel. Children's Colorado affiliated and approved study personal will have access to all study information collected at all involved study sites. However, other study sites will only have access to the information collected on patients enrolled at their site. We believe this system will contribute to the protection of PHI. The only PHI collected will be visit dates; all participants will be linked to their information via a unique study identifier.
The PI will periodically review the status of this protocol. Any unanticipated problems will be disclosed to COMIRB [Colorado Multiple Institutional Review Board] within five days with a cover letter detailing the assessment and actions to be taken.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Werewolf FLOW 50 Group | Active comparator | Device: Werewolf FLOW 50The Werewolf FLOW 50 electrocautery device will be used during surgical treatment for patients assigned to this group. |
| Control Group | Placebo comparator | Other: ControlNo electrocautery device will be used during surgical treatment for patients assigned to this group. |
Who may qualify
- Ages
- 12 to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (2 listed)
- Ages 12-18 (inclusive) at time of surgery
- Scheduled to undergo ACL reconstruction performed at Children's Hospital Colorado or associated network of care site.
Key exclusion criteria (3 listed)
- Underlying congenital or musculoskeletal disorders
- Pregnant females, prisoners, and wards of the state
- Persons deemed incompetent and those who have limited decision-making capacity
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 |
|---|---|---|
| Werewolf FLOW 50Use of Werewolf FLOW 50 electrocautery device during surgical treatment for ACL injury. This device is often used as standard of care when our other standard of care approach (use of no electrocautery device) is not used. | Device | Werewolf FLOW 50 Group |
| ControlAlso: No Electrocautery DeviceUse of no electrocautery device during surgical treatment for ACL injury. This approach is often used as standard of care when our other standard of care approach (use of Werewolf FLOW 50 electrocautery device) is not used. | Other | Control Group |
Primary outcome
Rates of Post-Operative Arthrofibrosis
Time frame: 1 year post-operative
Number of participants with post-operative arthrofibrosis
3 secondary outcomes
Range of Motion - Knee
Time frame: 1 year post-operative
Patient-Reported Outcomes Measurement Information System (PROMIS)
Time frame: Data reported below were collected approximately 6-months post-operatively.
Complications
Time frame: 1 year post-operative
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Sep 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- 510(k) Premarket Notification for Werewolf FLOW 50 DeviceLink provided by the sponsor.
- Individual participant dataSharing planned: No. IPD will not be shared with individuals outside of the authorized study team.
Related trials for Anterior Cruciate Ligament Injuries
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Effect of Transcutaneous Auricular Vagus Nerve Stimulation on Postoperative Recovery Quality in Patients Undergoing Anterior Cruciate Ligament Reconstruction
Anterior Cruciate Ligament Injuries, Recovery Quality
Not yet recruitingPhase 3
Extended Post-Operative Oral Tranexamic Acid Dosing After ACL Reconstruction
Anterior Cruciate Ligament Injuries, Anterior Cruciate Ligament Rupture
RecruitingObservational study
BioBrace® Augmentation in Anterior Cruciate Ligament Reconstruction Procedures
ACL Tears
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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. This study is not recruiting at the moment.
Jay C Albright, MD principal investigator
Children's Hospital Colorado
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Werewolf FLOW 50 in people with Anterior Cruciate Ligament Injuries and Anterior Cruciate Ligament Rupture, run by University of Colorado, Denver at 3 sites in United States.
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 2 inclusion and 3 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: finished, as of the sponsor's last update on 14 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in United States. 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. Some participants in this study may receive a placebo. 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?
Yes. Results are posted in the registry (first posted 14 Sep 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rates of Post-Operative Arthrofibrosis (time frame: 1 year post-operative). 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 14 Sep 2026.