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

• Sponsor: ConforMIS, Inc. (Industry)
• Overall Status: Completed
• CT.gov ID: NCT01717001
• Collaborator: (none)
• Enrollment: 66
• Locations: 2
• Actual Duration (Months): 24
• Patients Per Site: 33
• Patients Per Site Per Month: 1.4

Study Details

Study Description

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	Intervention/Treatment	Phase
Osteoarthritis

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 Design

• Study Type: Observational
• Actual Enrollment: 66 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
• Actual Study Start Date: Aug 1, 2012
• Actual Primary Completion Date: Aug 1, 2014
• Actual Study Completion Date: Aug 1, 2014

Arms and Interventions

Arm	Intervention/Treatment
ConforMIS Patients with ConforMIS implants
Standard Total Knee Implant Patients implanted with standard total knee implant

Outcome Measures

Primary Outcome Measures

1. Post-operative Range of Motion [at least 6 months post-surgery]

   Comparison of amount of flexion achieved by the knee between the two arms

Eligibility Criteria

Criteria

• Ages Eligible for Study: 40 Years to 70 Years
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

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.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	University of Tennessee	Knoxville	Tennessee	United States	37996
2	Tennessee Orthopedic Alliance	Nashville	Tennessee	United States	37203

Sponsors and Collaborators

• ConforMIS, Inc.

Investigators

• Principal Investigator: Richard D Komistek, PhD, Univeristy of Tennessee
• Principal Investigator: William Kurtz, MD, Tennessee Orthopedic Alliance

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: ConforMIS, Inc.
• ClinicalTrials.gov Identifier: NCT01717001
• Other Study ID Numbers: Komistek 1
• First Posted: Oct 30, 2012
• Last Update Posted: Dec 31, 2020
• Last Verified: Dec 1, 2020

• Individual Participant Data (IPD) Sharing Statement: No
• Plan to Share IPD: No
• Keywords provided by ConforMIS, Inc.: kinematics; knee joint
• Additional relevant MeSH terms: Osteoarthritis

Study Results

Participant Flow

Arm/Group Title	ConforMIS	Standard Total Knee Implant
Arm/Group Description	Patients with ConforMIS implants	Patients implanted with standard total knee implant
Period Title: Overall Study
STARTED	38	28
COMPLETED	32	24
NOT COMPLETED	6	4

Baseline Characteristics

Arm/Group Title	ConforMIS	Standard Total Knee Implant	Total
Arm/Group Description	Patients with ConforMIS implants	Patients implanted with standard total knee implant	Total of all reporting groups
Overall Participants	24	14	38
Age (years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [years]	60.2 (7.7)	66.7 (5.7)	62.6 (7.6)
Sex/Gender, Customized (Count of Participants)
Female	0 0%	0 0%	0 0%
Region of Enrollment (participants) [Number]
United States	24 100%	14 100%	38 100%

Outcome Measures

1. Primary Outcome

Title	Post-operative Range of Motion
Description	Comparison of amount of flexion achieved by the knee between the two arms
Time Frame	at least 6 months post-surgery

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	ConforMIS	Standard Total Knee Implant
Arm/Group Description	Patients with ConforMIS implants	Patients implanted with standard total knee implant
Measure Participants	24	14
Mean (Standard Deviation) [degrees]	103.8 (14.7)	95.8 (21.2)

Adverse Events

Arm/Group Title	ConforMIS		Standard Total Knee Implant
Arm/Group Description	Patients with ConforMIS implants		Patients implanted with standard total knee implant
All Cause Mortality
	ConforMIS		Standard Total Knee Implant
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	/ (NaN)		/ (NaN)
Serious Adverse Events
	ConforMIS		Standard Total Knee Implant
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/24 (0%)		0/14 (0%)
Other (Not Including Serious) Adverse Events
	ConforMIS		Standard Total Knee Implant
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/24 (0%)		0/14 (0%)

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.