Comparison of Knee Kinematics for Subjects Implanted With Either a ConforMIS or Traditional Knee Implant

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT01717001
Recruitment Status : Recruiting
First Posted : October 30, 2012
Last Update Posted : July 26, 2016
Information provided by (Responsible Party):
ConforMIS, Inc.

Brief Summary:

A better understanding of knee joint kinematics is important to explain the premature polyethylene wear failures within total knee arthroplasties (TKAs) and to help design a prosthesis that most closely approximates the normal knee. Previously, most experimental studies of knee kinematics have involved cadaveric, in vitro analyses, or have not tested the knee in a weight-bearing mode. Others have used exoskeletal linkages and skin markers that permit error due to undesired motions between markers and the underlying bone. More recently, fluoroscopy has been used to assess in vivo kinematics for subjects having a TKA.

ConforMIS has attempted to follow a clearly different path than the major orthopaedic companies. They have chosen to offer patients a personalized knee implant based off of each patient's femoral and tibial bone geometry. The hypothesis is that these subjects will experience a more normal-like kinematic pattern, eliminating paradoxical anterior sliding during weight-bearing knee flexion. Therefore, the objective for this study is to analyze the in vivo kinematics for 25 patients implanted with a personalized ConforMIS TKA and 25 patients implanted with a traditional TKA design to determine if there are any kinematic differences between these TKA designs.

Condition or disease

Detailed Description:
Each subject will be asked to perform five activities in one continuous sequence: (1) stand up from a chair, (2) walk up stairs, (3) walk down stairs, (4) level walking, and (5) a deep knee bend. Subjects will be video recorded from the waist down while performing the activities. The speed level of each trial will be based on the comfort level of the patient. The fluoroscopic images will be stored digitally for subsequent analysis on secure servers and workstations at the University of Tennessee.

Study Type : Observational
Estimated Enrollment : 100 participants
Observational Model: Case Control
Time Perspective: Prospective
Official Title: In Vivo Determination & Comparison of Knee Kinematics for Subjects Implanted With Either a Personalized ConforMIS or Traditional Knee Implant
Study Start Date : August 2012
Estimated Primary Completion Date : August 2017
Estimated Study Completion Date : November 2017

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Patients with ConforMIS implants
Standard Total Knee Implant
Patients implanted with standard total knee implant

Primary Outcome Measures :
  1. Patients with ConforMIS implant will experience more normal like kinematic pattern [ Time Frame: at least 6 months post surgery ]

Information from the National Library of Medicine

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Ages Eligible for Study:   40 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients who are at least 6 month post-op with a ConforMIS knee replacement or a standard total knee replacement who meets the inclusion/exclusion criteria

Inclusion Criteria:

  • At least 6 months post-op with no other surgical procedures conducted within the past 6 months
  • Between 40-70 years of age
  • Body weight of less than 250lbs
  • BMI of less than 38
  • Pregnant females will be excluded
  • TKA patients will be judged Clinically successful with an American Knee Society score of greater than 90
  • Must have 100 degrees post-op passive flexion with no ligamentous laxity or pain
  • Participants must be able to walk on level ground without aid of any kind and ascend/descend stairs without assistance.
  • All potential subjects will have either a personalized ConforMIS™ TKA or a traditional TKA manufactured by an orthopaedic company other than ConforMIS.
  • Patients from the physician's list who do not meet the study requirements will not be considered.
  • Patients must be willing to sign the Informed Consent and HIPAA forms to participate in the study.
  • Patients must be between 160cm (5'3) and 193cm (6'4) tall.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01717001

Contact: Richard Komistek, PhD 865-974-2093
Contact: William Hamel, PhD 865-974-9376

United States, Tennessee
University of Tennessee Not yet recruiting
Knoxville, Tennessee, United States, 37996
Contact: Richard D Komistek, PhD    865-974-2093   
Principal Investigator: Richard D Komistek, PhD         
Sub-Investigator: William R Hamel, PhD         
Sub-Investigator: Adrija Sharma, PhD         
Tennessee Orthopedic Alliance Recruiting
Nashville, Tennessee, United States, 37203
Contact: William B Kurtz, MD    865-974-2093   
Principal Investigator: William B Kurtz, MD         
Sponsors and Collaborators
ConforMIS, Inc.
Principal Investigator: Richard D Komistek, PhD Univeristy of Tennessee
Principal Investigator: William Kurtz, MD Tennessee Orthopedic Alliance

Responsible Party: ConforMIS, Inc. Identifier: NCT01717001     History of Changes
Other Study ID Numbers: Komistek 1
First Posted: October 30, 2012    Key Record Dates
Last Update Posted: July 26, 2016
Last Verified: July 2016
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Keywords provided by ConforMIS, Inc.:
knee joint

Additional relevant MeSH terms:
Joint Diseases
Musculoskeletal Diseases
Rheumatic Diseases