OsteoarthritisNCT02501733
Medacta GMK Sphere® Multicenter Post-Market Outcomes Study
A study testing Medacta GMK Sphere® Medial Knee Prosthesis in people with Osteoarthritis, run by Medacta USA at 5 sites in United States.
Trial summary
This study is to average Forgotten Knee Score (FJS) of those patients receiving the Medacta GMK Sphere® knee at the two and five year time points. 70 subjects, enrolled at the data coordinating center in Medacta GMK Sphere® vs Posterior Stabilized study (WIRB Pro Num: 20141994) and randomized to the Sphere arm, will… Read more about this study
- Who is it for?
- Ages 21 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- Osteoarthritis
- What is being tested?
- Medacta GMK Sphere® Medial Knee Prosthesis
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 260 participants
- Where
- 5 sitesUnited States
- Study dates
- Jun 2015to 5 Dec 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 21 to 80 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Patients willing to sign the informed consent
- Patients able to comply with follow-up requirements including postoperative weight bearing restrictions and self evaluations.
- Male and non-pregnant female patients ages 21 - 80 years of age at the time of surgery.
- Patients requiring a primary total knee replacement.
- Patients with a diagnosis of osteoarthritis (OA), traumatic arthritis (TA), or avascular necrosis (AVN).
- Patients with intact collateral ligaments.
Who cannot join
- Patients with inflammatory arthritis.
- Patients that are morbidly obese, body mass index (BMI) > 40.
- Patients with a history of total or unicompartmental reconstruction of the affected joint.
- Patients that have had a high tibial osteotomy or femoral osteotomy.
- Patients with neuromuscular or neurosensory deficiency, which would limit the ability to assess the performance of the device.
- Patients with a systemic or metabolic disorder leading to progressive bone deterioration.
Show all 11Show fewer
- Patients that are immunologically compromised, or receiving chronic steroids (> 30 days).
- Patients bone stock is compromised by disease or infection, which cannot provide adequate support and/or fixation to the prosthesis.
- Patients with knee fusion to the affected joint.
- Patients with an active or suspected latent infection in or about the knee joint.
- Patients that are prisoners.
Trial locations and contacts
5 sites in 1 country.
5 sites in 1 country
United States5 sites
Texas Orthopedics
Austin, Texas, 78759
Norhtwestern University
Chicago, Illinois, 60611
Tulane University
New Orleans, Louisiana, 70112
McBride Orthopedic Hospital
Oklahoma City, Oklahoma, 73103
Spokane Joint Replacement Center
Spokane, Washington, 99218
About this study
Official title: Medacta GMK Sphere® Medial Pivot, Cruciate Substituting Multicenter, Post-Market Outcomes Study
This study is to average Forgotten Knee Score (FJS) of those patients receiving the Medacta GMK Sphere® knee at the two and five year time points. 70 subjects, enrolled at the data coordinating center in Medacta GMK Sphere® vs Posterior Stabilized study (WIRB Pro Num: 20141994) and randomized to the Sphere arm, will have their data utilized for this study.
- Conditions
- Osteoarthritis
- Being tested
- Medacta GMK Sphere® Medial Knee Prosthesis
- Keywords
- Total Knee Replacement, Total Knee Arthroplasty
- Medical subject headings
- Osteoarthritis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Medacta GMK Sphere® Medial Knee ProsthesisDevice
Also called Total Knee Arthroplasty, Total Knee Prosthesis
There is no consensus within the Arthroplasty community as to whether a traditional post and cam-style Posterior Stabilized total knee device is superior to a medial-pivot, more congruent device. However, the majority of surgeons seem to prefer the former, though there is a minority that uses the latter device with great success.
To date, there have been few prospective trials directly comparing these devices, and none with the latest generation of Total Knee Arthroplasty implants. Almost all such studies have been retrospective and/or utilizing older generation devices.
| Study group | Role | What they receive |
|---|---|---|
| Medacta GMK Sphere® Knee Prosthesis | Other | All subjects enrolled will receive the Medacta GMK Sphere® Medial Knee Prosthesis Receives: Device: Medacta GMK Sphere® Medial Knee Prosthesis |
What is being measured
The primary outcome is the main question the study is designed to answer.
Evaluate the change in Forgotten Knee Scores (FJS) of those patients receiving the Medacta GMK Sphere from baseline to years 2 and 5 post-operatively.
Knee function-patients ability to forget the artificial joint in everyday life.
Measured: Baseline, 2 and 5 year time points
Secondary outcomes (4)
Total Knee Society Score (KSS)
Total Knee Society score questionnaire to assess pain and function
Measured: Pre-operative, 6 weeks, 3-6 months, 1,2,3,4 and 5 years.
Krackow Activity Scale (KAS)
The Krackow Activity Scale (KAS) lower extremity activity scale.
Measured: Pre-operative, 6 weeks, 3-6 months, 1,2,3,4 and 5 years
Radiographic Analysis
Measured: Pre-operative, 6 weeks, 3-6 months, 1,2,3,4 and 5 years
AP long standing X-ray
Determine degree of Varus or Valgus
Measured: Pre-operative and 6 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Jul 2015 (estimated)
- Study startJun 2015
- Primary completion5 Dec 2024
- Study completion5 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for OsteoarthritisStudies of the same condition, open and under way.
- 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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 260 participants (actual)
Sponsor and investigators
- Lead sponsor
- Medacta USA
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02501733
- Sponsor's protocol ID
- 121416-01
- Status last verified
- Sep 2025
- First submitted
- 25 Jun 2015
- Last updated
- 25 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 25 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Medacta GMK Sphere® Medial Pivot, Cruciate Substituting Multicenter, Post-Market Outcomes Study
- ClinicalTrials.gov ID
- NCT02501733
- Acronym / sponsor ID
- 121416-01
- Conditions
- Osteoarthritis
- Keywords
- Total Knee Replacement, Total Knee Arthroplasty
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 260 participants (actual)
- Lead sponsor
- Medacta USAIndustry (pharma, biotech, devices)
- Study start
- Jun 2015 (actual)
- Primary completion
- 5 Dec 2024 (actual)
- Study completion
- 5 Dec 2024 (actual)
- First posted
- 17 Jul 2015 (estimated)
- 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 study is to average Forgotten Knee Score (FJS) of those patients receiving the Medacta GMK Sphere® knee at the two and five year time points. 70 subjects, enrolled at the data coordinating center in Medacta GMK Sphere® vs Posterior Stabilized study (WIRB Pro Num: 20141994) and randomized to the Sphere arm, will have their data utilized for this study.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Medacta GMK Sphere® Knee Prosthesis | Other | Device: Medacta GMK Sphere® Medial Knee ProsthesisAll subjects enrolled will receive the Medacta GMK Sphere® Medial Knee Prosthesis |
Who may qualify
- Ages
- 21 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Patients willing to sign the informed consent
- Patients able to comply with follow-up requirements including postoperative weight bearing restrictions and self evaluations.
- Male and non-pregnant female patients ages 21 - 80 years of age at the time of surgery.
- Patients requiring a primary total knee replacement.
- Patients with a diagnosis of osteoarthritis (OA), traumatic arthritis (TA), or avascular necrosis (AVN).
Key exclusion criteria (11 listed)
- Patients with inflammatory arthritis.
- Patients that are morbidly obese, body mass index (BMI) > 40.
- Patients with a history of total or unicompartmental reconstruction of the affected joint.
- Patients that have had a high tibial osteotomy or femoral osteotomy.
- Patients with neuromuscular or neurosensory deficiency, which would limit the ability to assess the performance of the device.
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 |
|---|---|---|
| Medacta GMK Sphere® Medial Knee ProsthesisAlso: Total Knee Arthroplasty, Total Knee ProsthesisThere is no consensus within the Arthroplasty community as to whether a traditional post and cam-style Posterior Stabilized total knee device is superior to a medial-pivot, more congruent device. However, the majority of surgeons seem to prefer the former, though there is a minority that uses the latter device with great success. To date, there have been few prospective trials directly comparing these devices, and none with the latest generation of Total Knee Arthroplasty implants. Almost all such studies have been retrospective and/or utilizing older generation devices. | Device | Medacta GMK Sphere® Knee Prosthesis |
Primary outcome
Evaluate the change in Forgotten Knee Scores (FJS) of those patients receiving the Medacta GMK Sphere from baseline to years 2 and 5 post-operatively.
Time frame: Baseline, 2 and 5 year time points
Knee function-patients ability to forget the artificial joint in everyday life.
4 secondary outcomes
Total Knee Society Score (KSS)
Time frame: Pre-operative, 6 weeks, 3-6 months, 1,2,3,4 and 5 years.
Krackow Activity Scale (KAS)
Time frame: Pre-operative, 6 weeks, 3-6 months, 1,2,3,4 and 5 years
Radiographic Analysis
Time frame: Pre-operative, 6 weeks, 3-6 months, 1,2,3,4 and 5 years
AP long standing X-ray
Time frame: Pre-operative and 6 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Sep 2025.
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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.
The record lists no contact. Use the official record to reach the sponsor.
5 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Medacta GMK Sphere® Medial Knee Prosthesis in people with Osteoarthritis, run by Medacta USA at 5 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 6 inclusion and 11 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 25 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 5 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. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Evaluate the change in Forgotten Knee Scores (FJS) of those patients receiving the Medacta GMK Sphere from baseline to years 2 and 5 post-operatively. (time frame: Baseline, 2 and 5 year time points). 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 25 Sep 2025.