A Single Time-Point Study to Evaluate the ConforMIS iTotal® (CR) Knee Versus Off-the-Shelf (STEPS)

A Single Time-Point Study to Evaluate the ConforMIS iTotal® (CR) Knee Replacement System Versus Off-the-Shelf Replacement

It has been noted that patients "dramatically overestimate their functional ability early after surgery." Despite use of assistive devices increasing and functional testing scores decreasing post-surgery, the patient reported outcome scores fail to show worsening. Outcome questionnaires will be administered and functional testing will be conducted on all patients to capture these changes.

Study Overview

• Status: Completed
• Conditions: Osteoarthritis
• Intervention / Treatment: Device: ConforMIS Total Knee Replacement System; Device: Off-the-Shelf Knee Replacement System

Detailed Description

The functional testing used in this study consists of tests that physical therapists use daily as objective methods to assess patients' functional status. The testing is designed to closely mimic daily activities that the patients are familiar with.

• Study Type: Observational
• Enrollment (Actual): 873

Contacts and Locations

Study Locations

• Germany
  • Kassel, Germany
    • Vitos Orthopädische Klinik Kassel
  • Neutraubling, Germany
    • MedArtes
  • Radebeul, Germany
    • Elblandkliniken Stiftung
  • Stuttgart, Germany
    • Sportklinik Stuttgart
• United States
  • Colorado
    • Parker, Colorado, United States, 80134
      • Denver-Vail Orthopedics
  • Florida
    • Fort Myers, Florida, United States, 33919
      • Institute for Orthopaedic Surgery & Sports Medicine
    • Miami, Florida, United States, 33176
      • Baptist Health South Florida
    • Port Saint Lucie, Florida, United States, 34996
      • Coastal Orthopaedic & Sports Medicine Ctr
  • Maryland
    • Bethesda, Maryland, United States, 20817
      • Bethesda Orthopedic
  • Massachusetts
    • Woburn, Massachusetts, United States, 01801
      • Excel Orthopaedic Specialists
  • Michigan
    • Battle Creek, Michigan, United States, 49015
      • Great Lakes Bone & Joint Center
    • West Bloomfield, Michigan, United States, 48323
      • Lederman-Kwartowitz Center for Orthopedics and Sports Medicine
  • Nevada
    • Henderson, Nevada, United States, 89052
      • Orthopaedic Institute of Henderson
  • New York
    • Potsdam, New York, United States, 13676
      • St. Lawrence Health System
  • South Carolina
    • Spartanburg, South Carolina, United States, 29303
      • Orthopedic Specialties of Spartanburg
  • Texas
    • Cypress, Texas, United States, 77429
      • Advanced Orthopedics & Sports Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study will include a 1:1 ratio of patients enrolled into both the iTotal arm and the off-the-shelf total knee arm.

Description

Inclusion Criteria:

• Implant must be at least 6 months post-op and doing well
• Patient has had a total CR knee implant
• > 18 years of age

Exclusion Criteria:

• Simultaneous bilateral procedure occurred
• BMI > 40
• Other physical disability that requires an aid for walking or disability affecting the hips, spine, contralateral knee or other joint that limits function
• Participation in another clinical study which would confound results
• Inability to complete the protocol in the opinion of the clinical staff due to safety or other reasons

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Other

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
ConforMIS iTotal Knee Replacement System; Patients who have had an iTotal knee replacement at least 6 months prior to testing	Device: ConforMIS Total Knee Replacement System; Total knee replacement system using a patient specific implant.
Off-the-Shelf Knee Replacement System; Patients who have had an off-the-shelf knee replacement at least 6 months prior to testing	Device: Off-the-Shelf Knee Replacement System; Total knee replacement system not using a patient specific implant.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Functional Outcome time differences between the two groups	The study primary endpoint is to compare functional testing time between patients implanted with the iTotal implant verses the off-the-shelf implants	at least 6 months post-op

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Outcomes questionnaire- Knee Society Score	Comparing different patient outcome scores between the two groups	At least 6 months post op
Outcomes questionnaire- KOOS	Comparing different patient outcome scores between the two groups	At least 6 months post op
Outcomes questionnaire- Forgotten Joint Score	Comparing different patient outcome scores between the two groups	At least 6 months post op

Collaborators and Investigators

• Sponsor: Restor3D
• Investigators: Principal Investigator: Robert Tait, MD, Orthopaedic Institute of Henderson; Study Chair: Mary O'Connor, MD, Yale University

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2014
• Primary Completion (Actual): October 1, 2016
• Study Completion (Actual): December 1, 2016

Study Registration Dates

• First Submitted: September 22, 2014
• First Submitted That Met QC Criteria: September 25, 2014
• First Posted (Estimated): September 29, 2014

Study Record Updates

• Last Update Posted (Actual): October 25, 2023
• Last Update Submitted That Met QC Criteria: October 23, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Osteoarthritis
• Other Study ID Numbers: 14-001

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: Yes
• product manufactured in and exported from the U.S.: Yes