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Calypso Knee System Clinical Study, OUS

Evaluation of the Calypso Knee System for Symptom Relief in Subjects With Medial Knee Osteoarthritis, OUS

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03838978
Enrollment
81
Registered
2019-02-12
Start date
2019-02-08
Completion date
2025-03-14
Last updated
2026-07-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Osteoarthritis, Knee

Brief summary

A study to evaluate the safety and effectiveness of the Calypso Knee System when used in subjects with symptomatic osteoarthritis of the medial compartment of the knee.

Detailed description

Prospective, multicenter clinical study of the Calypso Knee System. A total of 81 subjects were enrolled in this study. Male or female subjects age 25 to 65 years, with a diagnosis of medial knee osteoarthritis and study knee pain with an overall WOMAC pain score ≥ 40 (scale 0-100). The Calypso group was investigated under two clinical protocols, CP0001 in the USA, and CP0002 in Europe. Both clinical protocols followed the same supporting protocols and plans, such as radiographic, statistical, Clinical Events Committee (CEC), etc. The results from the combined analysis have been reported in both NCT03671213 (CP0001) and NCT03838978 (CP0002).

Interventions

The Calypso Knee System is an extra-capsular knee implant designed to fill the therapeutic gap between conservative care and more invasive surgical interventions for knee osteoarthritis.

Sponsors

Moximed
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

Single Arm Study Design

Eligibility

Sex/Gender
ALL
Age
25 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

1. Participants age - 25 to 65 years 2. Body Mass Index (BMI) of \< 35, Weight \< 300 lbs (136 kg) 3. Knee osteoarthritis pain on the inner side of knee that has continued after at least 6 months of non-operative treatment

Exclusion criteria

1. Symptoms of osteoarthritis in the other knee or in lateral (outer) or patellofemoral compartments of the target knee 2. Knee ligament or meniscal instability 3. Other bone or joint conditions such as Rheumatoid arthritis, Paget's disease, Charcot's disease or general conditions such as allergy or hypersensitivity to certain metals, active infection, certain neurological conditions, use of medication such as steroids or chemotherapy that could impact study participation or results

Design outcomes

Primary

MeasureTime frameDescription
Percentage of Participants With Composite Clinical Success (CCS)From baseline to 24 monthsA subject is considered a Composite Clinical Success (CCS), at 24 months, if the subject meets all of the following: 1. Clinically significant improvement of at least 20% from baseline on the WOMAC pain questions in the KOOS Knee questionnaire with a change of ≥10 points 2. Clinically significant improvement of at least 20% from baseline on the WOMAC function questions in the KOOS Knee questionnaire with a change of ≥10 points 3. Freedom from the following device-related serious adverse events: * Deep infection requiring surgical intervention (Both arms) * Damage to adjacent neurovascular or ligament structures necessitating reconstruction (Both arms) * Non-union (HTO only) 4. Maintenance of implant integrity as evaluated by radiographic assessment 5. Endpoint Subsequent Surgical Intervention (SSI)

Secondary

MeasureTime frameDescription
Time to Full Weight Bearing (Days)Through study completion (number of days to full weight bearing)
WOMAC Pain Percent Change to Month 3From baseline to 3 monthsThe Knee Injury and Osteoarthritis Outcome Score (KOOS) Knee Survey includes the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) in its complete and original format (with permission), and WOMAC scores can be calculated from the KOOS Knee questionnaire. The response to each question is summed and the resultant scores are transformed to a 0-100 scale. A WOMAC score of zero (0) represents no knee problems and one hundred (100) represents extreme knee problems.
WOMAC Pain Percent Change to Month 24From baseline to 24 monthsThe Knee Injury and Osteoarthritis Outcome Score (KOOS) Knee Survey includes the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) in its complete and original format (with permission), and WOMAC scores can be calculated from the KOOS Knee questionnaire. The response to each question is summed and the resultant scores are transformed to a 0-100 scale. A WOMAC score of zero (0) represents no knee problems and one hundred (100) represents extreme knee problems.
WOMAC Function Percent Change to Month 3From baseline to 3 monthsThe Knee Injury and Osteoarthritis Outcome Score (KOOS) Knee Survey includes the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) in its complete and original format (with permission), and WOMAC scores can be calculated from the KOOS Knee questionnaire. The response to each question is summed and the resultant scores are transformed to a 0-100 scale. A WOMAC score of zero (0) represents no knee problems and one hundred (100) represents extreme knee problems.
WOMAC Function Percent Change to Month 24From baseline to 24 monthsThe Knee Injury and Osteoarthritis Outcome Score (KOOS) Knee Survey includes the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) in its complete and original format (with permission), and WOMAC scores can be calculated from the KOOS Knee questionnaire. The response to each question is summed and the resultant scores are transformed to a 0-100 scale. A WOMAC score of zero (0) represents no knee problems and one hundred (100) represents extreme knee problems.

Countries

Belgium, Poland

Contacts

PRINCIPAL_INVESTIGATORDavid Flanigan, MD

Ohio State University

Participant flow

Pre-assignment details

The Calypso Clinical Study enrolled 81 subjects in the investigational (Calypso) arm. The historical control arm (HTO) is from a prior Moximed sponsored clinical trial. The results presented include data from the historical control arm for comparison, per the protocol.

Participants by arm

ArmCount
Calypso Knee System
Calypso Knee System: The Calypso Knee System is an extra-capsular knee implant designed to fill the therapeutic gap between conservative care and more invasive surgical interventions for knee osteoarthritis.
81
High Tibial Osteotomy (HTO)
Historical Control: HTO is a surgical treatment intended to reduce or eliminate pain and improve the function of a knee affected by medial compartment OA. All subjects underwent an open wedge osteotomy (OWO).
81
Total162

Baseline characteristics

CharacteristicCalypso Knee SystemHigh Tibial Osteotomy (HTO)Total
Age, Continuous51.2 years
STANDARD_DEVIATION 7.71
52.5 years
STANDARD_DEVIATION 7.58
51.8 years
STANDARD_DEVIATION 7.65
Body Mass Index (BMI)28.4 kg/m^2
STANDARD_DEVIATION 3.44
29.3 kg/m^2
STANDARD_DEVIATION 4.36
28.8 kg/m^2
STANDARD_DEVIATION 3.94
Ethnicity (NIH/OMB)
Hispanic or Latino
3 Participants1 Participants4 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
78 Participants50 Participants128 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants30 Participants30 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Black or African American
1 Participants0 Participants1 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants1 Participants1 Participants
Race (NIH/OMB)
White
80 Participants80 Participants160 Participants
Sex: Female, Male
Female
32 Participants28 Participants60 Participants
Sex: Female, Male
Male
49 Participants53 Participants102 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 810 / 81
other
Total, other adverse events
20 / 8114 / 81
serious
Total, serious adverse events
18 / 8139 / 81

Outcome results

Primary

Percentage of Participants With Composite Clinical Success (CCS)

A subject is considered a Composite Clinical Success (CCS), at 24 months, if the subject meets all of the following: 1. Clinically significant improvement of at least 20% from baseline on the WOMAC pain questions in the KOOS Knee questionnaire with a change of ≥10 points 2. Clinically significant improvement of at least 20% from baseline on the WOMAC function questions in the KOOS Knee questionnaire with a change of ≥10 points 3. Freedom from the following device-related serious adverse events: * Deep infection requiring surgical intervention (Both arms) * Damage to adjacent neurovascular or ligament structures necessitating reconstruction (Both arms) * Non-union (HTO only) 4. Maintenance of implant integrity as evaluated by radiographic assessment 5. Endpoint Subsequent Surgical Intervention (SSI)

Time frame: From baseline to 24 months

ArmMeasureValue (NUMBER)
Calypso Knee SystemPercentage of Participants With Composite Clinical Success (CCS)83.5 percentage of subjects
High Tibial Osteotomy (HTO)Percentage of Participants With Composite Clinical Success (CCS)57.2 percentage of subjects
Comparison: For missing data in both Arms/Groups, multiple imputation was performed for the primary CCS analysis.
Secondary

Time to Full Weight Bearing (Days)

Time frame: Through study completion (number of days to full weight bearing)

ArmMeasureValue (MEAN)Dispersion
Calypso Knee SystemTime to Full Weight Bearing (Days)13.4 daysStandard Deviation 10.12
High Tibial Osteotomy (HTO)Time to Full Weight Bearing (Days)58 daysStandard Deviation 39.91
Secondary

WOMAC Function Percent Change to Month 24

The Knee Injury and Osteoarthritis Outcome Score (KOOS) Knee Survey includes the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) in its complete and original format (with permission), and WOMAC scores can be calculated from the KOOS Knee questionnaire. The response to each question is summed and the resultant scores are transformed to a 0-100 scale. A WOMAC score of zero (0) represents no knee problems and one hundred (100) represents extreme knee problems.

Time frame: From baseline to 24 months

ArmMeasureValue (MEAN)Dispersion
Calypso Knee SystemWOMAC Function Percent Change to Month 24-73.9 percentage of changeStandard Deviation 29.6
High Tibial Osteotomy (HTO)WOMAC Function Percent Change to Month 24-58.8 percentage of changeStandard Deviation 35.8
Secondary

WOMAC Function Percent Change to Month 3

The Knee Injury and Osteoarthritis Outcome Score (KOOS) Knee Survey includes the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) in its complete and original format (with permission), and WOMAC scores can be calculated from the KOOS Knee questionnaire. The response to each question is summed and the resultant scores are transformed to a 0-100 scale. A WOMAC score of zero (0) represents no knee problems and one hundred (100) represents extreme knee problems.

Time frame: From baseline to 3 months

ArmMeasureValue (MEAN)Dispersion
Calypso Knee SystemWOMAC Function Percent Change to Month 3-52.2 percentage of changeStandard Deviation 32
High Tibial Osteotomy (HTO)WOMAC Function Percent Change to Month 3-25.2 percentage of changeStandard Deviation 37
Secondary

WOMAC Pain Percent Change to Month 24

The Knee Injury and Osteoarthritis Outcome Score (KOOS) Knee Survey includes the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) in its complete and original format (with permission), and WOMAC scores can be calculated from the KOOS Knee questionnaire. The response to each question is summed and the resultant scores are transformed to a 0-100 scale. A WOMAC score of zero (0) represents no knee problems and one hundred (100) represents extreme knee problems.

Time frame: From baseline to 24 months

ArmMeasureValue (MEAN)Dispersion
Calypso Knee SystemWOMAC Pain Percent Change to Month 24-76.0 percentage of changeStandard Deviation 28.2
High Tibial Osteotomy (HTO)WOMAC Pain Percent Change to Month 24-64.7 percentage of changeStandard Deviation 33
Secondary

WOMAC Pain Percent Change to Month 3

The Knee Injury and Osteoarthritis Outcome Score (KOOS) Knee Survey includes the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) in its complete and original format (with permission), and WOMAC scores can be calculated from the KOOS Knee questionnaire. The response to each question is summed and the resultant scores are transformed to a 0-100 scale. A WOMAC score of zero (0) represents no knee problems and one hundred (100) represents extreme knee problems.

Time frame: From baseline to 3 months

ArmMeasureValue (MEAN)Dispersion
Calypso Knee SystemWOMAC Pain Percent Change to Month 3-55.5 percentage of changeStandard Deviation 29.3
High Tibial Osteotomy (HTO)WOMAC Pain Percent Change to Month 3-33.4 percentage of changeStandard Deviation 35.8

Source: ClinicalTrials.gov · Data processed: Jul 30, 2026