Medacta GMK Sphere® vs. Medacta GMK PS Post-Market Outcomes Study

• ClinicalTrials.gov Identifier: NCT03391323
• Recruitment Status: Active, not recruiting
• First Posted: January 5, 2018
• Last Update Posted: September 28, 2021
• Sponsor: David F. Scott, MD
• Collaborator: Medacta USA
• Information provided by (Responsible Party): David F. Scott, MD, Spokane Joint Replacement Center

Study Description

Brief Summary:

The study is a prospective, randomized comparison of total knee arthroplasty with the Medacta GMK Sphere® knee compared to the Medacta GMK PS knee, with comparison to data from previous trials of similar study design.

Condition or disease	Intervention/treatment	Phase
Osteoarthritis; Osteoarthritis, Knee; Joint Disease	Device: Medacta GMK Sphere® Medial-Pivot Knee Prosthesis; Device: Medacta GMK PS Posterior Stabilized Knee Prosthesis	Not Applicable

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 218 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Single (Participant)
• Primary Purpose: Other
• Official Title: Medacta GMK Sphere® Medial-Pivot, Cruciate Substituting vs. Medacta GMK PS Posterior Stabilized Kne vs. OMNI Apex Knee Ultracongruent vs. Triathlon® Posterior Stabilized & Cruciate Substituting Outcomes Study
• Actual Study Start Date: April 2015
• Estimated Primary Completion Date: December 2023
• Estimated Study Completion Date: December 2023

Arms and Interventions

Arm	Intervention/treatment
Medacta GMK Sphere® Medial-Pivot Knee Prosthesis	Device: Medacta GMK Sphere® Medial-Pivot Knee Prosthesis
Medacta GMK PS Posterior Stabilized Knee Prosthesis	Device: Medacta GMK PS Posterior Stabilized Knee Prosthesis

Outcome Measures

Primary Outcome Measures :

1. Forgotten Joint Score (FJS) [ Time Frame: Change from baseline at 2 years and 5 years post-operative ]

   The average Forgotten Joint Score (FJS) of those patients receiving the Medacta GMK Sphere® knee prosthesis will be compared with the average FJS of those receiving the Medacta GMK PS knee prosthesis.

   The FJS total score range is 0-100, with higher scores indicating a higher degree of "forgetting" the artificial joint, that is, a lower degree of awareness.

Secondary Outcome Measures :

1. Total Knee Society Score (KSS) [ Time Frame: Pre-operative, 6 weeks, 6 months, 1, 2, 3, 4, and 5 years post-operative ]
   Clinical outcomes will be evaluated via the Knee Society Score (KSS). The KSS is subdivided into a Knee Assessment score which rates only the knee joint itself, and a Functional Assessment score which rates the subject's ability to walk and climb stairs. Both scores range from 0-100, with a higher score indicating a better outcome.
2. Lower Extremity Activity Scale (LEAS) [ Time Frame: Pre-operative, 6 weeks, 6 months, 1, 2, 3, 4, and 5 years post-operative ]
   Clinical outcomes will be evaluated via the Lower Extremity Activity Scale (LEAS). The LEAS scale range is 1-18, with a higher value indicating a higher level of activity.
3. Radiographic Analysis [ Time Frame: Pre-operative, 6 weeks, 6 months, 1, 2, 3, 4, and 5 years post-operative ]
   Radiographs will be assessed for radiolucency, migration and subsidence. An AP Longstanding view will be obtained pre-operatively, and at 6 weeks and 1 year post-operatively to determine degree of Varus or Valgus.

Eligibility Criteria

• Ages Eligible for Study: 21 Years to 80 Years (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Criteria

Inclusion Criteria:

• 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.

Exclusion Criteria:

• 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 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.
• Patients that are immunologically compromised, or receiving chronic steroids (>30 days), excluding inhalers.
• 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 whose surgery will utilize computer-assisted surgical navigation (CAOS) techniques.
• Patients whose surgery will utilize minimally invasive surgical techniques.
• Patients that are prisoners.

Contacts and Locations

Locations

United States, Washington

Spokane Joint Replacement Center

Spokane, Washington, United States, 99218

Sponsors and Collaborators

David F. Scott, MD

Medacta USA

Investigators

• Principal Investigator: David Scott, MD; Spokane Joint Replacement Center

More Information

• Responsible Party: David F. Scott, MD, Principal Investigator, Spokane Joint Replacement Center
• ClinicalTrials.gov Identifier: NCT03391323
• Other Study ID Numbers: SJRC-GMK
• First Posted: January 5, 2018
• Last Update Posted: September 28, 2021
• Last Verified: September 2021

Individual Participant Data (IPD) Sharing Statement:

• Plan to Share IPD: No

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: Yes

Additional relevant MeSH terms:

Osteoarthritis; Osteoarthritis, Knee; Joint Diseases; Arthritis; Musculoskeletal Diseases; Rheumatic Diseases