Patella: In Vivo Determination of 3D Patellofemoral Mechanics

• Sponsor: The University of Tennessee, Knoxville (Other)
• Overall Status: Completed
• CT.gov ID: NCT01290627
• Collaborator: DePuy Orthopaedics (Industry)
• Enrollment: 30
• Locations: 4
• Duration (Months): 7
• Patients Per Site: 7.5
• Patients Per Site Per Month: 1.1

Study Details

Study Description

Brief Summary

This study will analyze the tibio-femoral and patellofemoral (motion) and mechanics (forces) of participants having a normal knee or a total knee arthroplasty (TKA) using one or two different (TKA) devices Low Contract Stress (LCS) Posterior Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA). All knees will be analyzed using an image matching technique that will convert a two-dimensional (2D) fluoroscopic image into a three-dimensional (3D) image. In conjunction with the fluoroscopic analysis, electromyography (EMG) data, and ground reaction force (GRF) data will all be allow for a complete analysis of the knee joints. These results will help the orthopaedic community better understand knee motion so they can improve testing on existing implants and develop future implants that will further enhance patients' lives.

Condition or Disease	Intervention/Treatment	Phase
Arthroplasty Replacement Knee; Knee Prosthesis	Device: Subjects implanted with DePuy LCS PS RP TKA; Device: Subjects implanted with DePuy Sigma PS RP TKA

Study Design

• Study Type: Observational
• Actual Enrollment: 30 participants
• Observational Model: Case-Only
• Time Perspective: Retrospective
• Official Title: In Vivo Determination of 3D Patellofemoral Mechanics
• Study Start Date: Feb 1, 2011
• Actual Primary Completion Date: Sep 1, 2011
• Actual Study Completion Date: Sep 1, 2011

Arms and Interventions

Arm	Intervention/Treatment
Knee Prosthesis LCS PS RP TKA Subjects implanted with DePuy Low Contact Stress (LCS) Poster Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Device: Subjects implanted with DePuy LCS PS RP TKA; Subjects implanted with DePuy Low Contact Stress (LCS) Poster Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)
Knee Prosthesis Sigma PS RP TKA Subjects implanted with a DePuy Sigma Posterior Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Device: Subjects implanted with DePuy Sigma PS RP TKA; Subjects implanted with a DePuy Sigma Posterior Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)
Control Subjects with normal knees

Outcome Measures

Primary Outcome Measures

1. Patella Flexion With Respect to Femur [Average post-operative time for LCS-PS group was 56 months. Average post-operative time for PS RP group was 55.7 months.]

   Full extension to maximum flexion. Degrees of flexion analyzed for participants with and without implants.

2. Patella Rotation With Respect to Femur [Average post-operative time for LCS-PS group was 56 months. Average post-operative time for PS RP group was 55.7 months.]

   Patellar rotation from full extension to maximum flexion for subjects with and without implants. A positive measurement of patellar rotation refers to positive flexion of the patella about the medial-lateral axis, where the patella component rotates so that the top of the patella rotates toward the femur and the bottom rotates away. Conversely, a negative measurement refers to negative flexion of the patella about this axis, where the patellar component rotates so that the top of the patella moves away from the femur and the bottom moves towards.

3. Patella Tilt With Respect to Femur [Average post-operative time for LCS-PS group was 56 months. Average post-operative time for PS RP group was 55.7 months.]

   full extension to maximum flexion for participants with and without implants.

4. Normalized Medial Patella Contact Point Translation [Average post-operative time for LCS-PS group was 56 months. Average post-operative time for PS RP group was 55.7 months.]

   full extension to maximum flexion for participants with and without implants. Position of the patellar contact point was determined by locating the closest point to the femur on the patella throughout flexion. There are 2 patello-femoral contact points: a point on the medial aspect of the patella and a point on the lateral aspect of the patella. Throughout flexion, the medial contact point generally moves closer to the top of the patella (hence the positive value for the results). The translation of this contact point is normalized to report a ratio between -1 and 1. In other words, the distance the point has traveled compared to the total height of the patella. For example, if the patella is 8 cm in height and the point travels approximately 2 cm upwards during flexion, the value would be reported as +2/8 = +0.25. Definition of normalized: "multiply (a series, function, or item of data) by a factor that makes the norm or some associated quantity such as an integral equal

5. Normalized Lateral Patella Contact Point Translation [Average post-operative time for LCS-PS group was 56 months. Average post-operative time for PS RP group was 55.7 months.]

   full extension to maximum flexion for participants with and without implants. Position of patellar contact point was determined by locating closest point to femur on patella throughout flexion. There are 2 patello-femoral contact points: 1 point on the medial aspect of the patella and 1 point on the lateral aspect of the patella. Throughout flexion, lateral contact point generally moves closer to the top of the patella (hence, the positive value for the results). The translation of this contact point is normalized to report a ratio between -1 and 1. The distance the point has traveled compared to the total height of the patella. For example, if the patella is 8 cm in height and the point travels approximately 2 cm upwards during flexion, the value would be reported as +2/8 = +0.25. Definition of normalized: "multiply (a series, function, or item of data) by a factor that makes the norm or some associated quantity such as an integral equal to a desired value (usually 1)."

Eligibility Criteria

Criteria

• Ages Eligible for Study: 20 Years to 85 Years
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Inclusion Criteria:

1. Patients must be at least six months post-operative.

2. Potential subjects will have a body weight of less than 250 lbs.

3. Candidates must have an AKS score >70 post-operatively.

4. Patients must have passive flexion of at least 100.

5. Implanted group must have either an LCS PS RP TKA, having an anatomical patella, or Sigma PS RP TKA; or normal knee group must have normal knee.

6. Must be willing to sign both Informed Consent and HIPAA forms.

Exclusion Criteria:

1. Pregnant females.

2. Subjects not meeting study requirements.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Colorado Joint Replacement	Denver	Colorado	United States	80210
2	Porter Adventist Hospital	Denver	Colorado	United States	80210
3	Perkins Hall	Knoxville	Tennessee	United States	37996
4	Science and Engineering Research Facility	Knoxville	Tennessee	United States	37996

Sponsors and Collaborators

• The University of Tennessee, Knoxville
• DePuy Orthopaedics

Investigators

• Principal Investigator: Richard D. Komistek, Ph D, The University of Tennessee
• Principal Investigator: Douglas Dennis, MD, Colorado Joint Replacement, Porter Adventist Hosp

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: Richard Komistek, Principal Investigator, The University of Tennessee, Knoxville
• ClinicalTrials.gov Identifier: NCT01290627
• Other Study ID Numbers: 10035/IIS-000126; R011373372
• First Posted: Feb 7, 2011
• Last Update Posted: Oct 29, 2019
• Last Verified: Oct 1, 2019

Study Results

Participant Flow

Recruitment Details	Patients were recruited from the Colorado Joint Replacement practice of Drs. Doug Dennis and Brian Haas in Denver, CO after the study was approved by respective IRBs beginning 5/27/11.

Arm/Group Title	Knee Prosthesis LCS PS RP TKA	Knee Prosthesis Sigma PS RP TKA	Control
Arm/Group Description	Subjects implanted with DePuy Low Contact Stress (LCS) Poster Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects implanted with a DePuy Sigma Posterior Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects with normal knees
Period Title: Overall Study
STARTED	10	10	10
COMPLETED	10	10	10
NOT COMPLETED	0	0	0

Baseline Characteristics

Arm/Group Title	Knee Prosthesis LCS PS RP TKA	Knee Prosthesis Sigma PS RP TKA	Control	Total
Arm/Group Description	Subjects implanted with DePuy Low Contact Stress (LCS) Poster Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects implanted with a DePuy Sigma Posterior Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects with normal knees	Total of all reporting groups
Overall Participants	10	10	10	30
Age (Count of Participants)
<=18 years	0 0%	0 0%	0 0%	0 0%
Between 18 and 65 years	5 50%	5 50%	10 100%	20 66.7%
>=65 years	5 50%	5 50%	0 0%	10 33.3%
Age (years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [years]	62.5 (7.8)	64.3 (8.7)	34.2 (8.9)	53.67 (16.18)
Sex: Female, Male (Count of Participants)
Female	4 40%	1 10%	8 80%	13 43.3%
Male	6 60%	9 90%	2 20%	17 56.7%
Region of Enrollment (participants) [Number]
United States	10 100%	10 100%	10 100%	30 100%

Outcome Measures

1. Primary Outcome

Title	Patella Flexion With Respect to Femur
Description	Full extension to maximum flexion. Degrees of flexion analyzed for participants with and without implants.
Time Frame	Average post-operative time for LCS-PS group was 56 months. Average post-operative time for PS RP group was 55.7 months.

Outcome Measure Data

Analysis Population Description

Unit analyzed is an orthopaedic implant and subjects with normal knees do not have orthopaedic implants.

Arm/Group Title	Knee Prosthesis LCS PS RP TKA	Knee Prosthesis Sigma PS RP TKA	Control
Arm/Group Description	Subjects implanted with DePuy Low Contact Stress (LCS) Poster Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects implanted with a DePuy Sigma Posterior Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects with normal knees
Measure Participants	10	10	10
Measure Implants/Knees	10	10	10
Mean (Standard Deviation) [degrees]	80.0 (13.6)	83.4 (12.9)	93.7 (12.9)

2. Primary Outcome

Title	Patella Rotation With Respect to Femur
Description	Patellar rotation from full extension to maximum flexion for subjects with and without implants. A positive measurement of patellar rotation refers to positive flexion of the patella about the medial-lateral axis, where the patella component rotates so that the top of the patella rotates toward the femur and the bottom rotates away. Conversely, a negative measurement refers to negative flexion of the patella about this axis, where the patellar component rotates so that the top of the patella moves away from the femur and the bottom moves towards.
Time Frame	Average post-operative time for LCS-PS group was 56 months. Average post-operative time for PS RP group was 55.7 months.

Outcome Measure Data

Analysis Population Description

Unit analyzed is an orthopaedic implant and subjects with normal knees do not have orthopaedic implants.

Arm/Group Title	Knee Prosthesis LCS PS RP TKA	Knee Prosthesis Sigma PS RP TKA	Control
Arm/Group Description	Subjects implanted with DePuy Low Contact Stress (LCS) Poster Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects implanted with a DePuy Sigma Posterior Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects with normal knees
Measure Participants	10	10	10
Measure Implants/Knees	10	10	10
Mean (Standard Deviation) [degrees]	.5 (5.0)	-.06 (3.1)	-1.6 (6.1)

3. Primary Outcome

Title	Patella Tilt With Respect to Femur
Description	full extension to maximum flexion for participants with and without implants.
Time Frame	Average post-operative time for LCS-PS group was 56 months. Average post-operative time for PS RP group was 55.7 months.

Outcome Measure Data

Analysis Population Description

Unit analyzed is an orthopaedic implant and subjects with normal knees do not have orthopaedic implants.

Arm/Group Title	Knee Prosthesis LCS PS RP TKA	Knee Prosthesis Sigma PS RP TKA	Control
Arm/Group Description	Subjects implanted with DePuy Low Contact Stress (LCS) Poster Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects implanted with a DePuy Sigma Posterior Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects with normal knees
Measure Participants	10	10	10
Measure Implants/Knees	10	10	10
Mean (Standard Deviation) [degrees]	4.2 (5.1)	2.6 (6.4)	5.3 (5.9)

4. Primary Outcome

Title	Normalized Medial Patella Contact Point Translation
Description	full extension to maximum flexion for participants with and without implants. Position of the patellar contact point was determined by locating the closest point to the femur on the patella throughout flexion. There are 2 patello-femoral contact points: a point on the medial aspect of the patella and a point on the lateral aspect of the patella. Throughout flexion, the medial contact point generally moves closer to the top of the patella (hence the positive value for the results). The translation of this contact point is normalized to report a ratio between -1 and 1. In other words, the distance the point has traveled compared to the total height of the patella. For example, if the patella is 8 cm in height and the point travels approximately 2 cm upwards during flexion, the value would be reported as +2/8 = +0.25. Definition of normalized: "multiply (a series, function, or item of data) by a factor that makes the norm or some associated quantity such as an integral equal
Time Frame	Average post-operative time for LCS-PS group was 56 months. Average post-operative time for PS RP group was 55.7 months.

Outcome Measure Data

Analysis Population Description

Unit analyzed is an orthopaedic implant and subjects with normal knees do not have orthopaedic implants.

Arm/Group Title	Knee Prosthesis LCS PS RP TKA	Knee Prosthesis Sigma PS RP TKA	Control
Arm/Group Description	Subjects implanted with DePuy Low Contact Stress (LCS) Poster Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects implanted with a DePuy Sigma Posterior Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects with normal knees
Measure Participants	10	10	10
Measure Implants/Knees	10	10	10
Mean (Standard Deviation) [ratio of patella height]	.34 (.18)	.12 (.17)	.40 (.41)

5. Primary Outcome

Title	Normalized Lateral Patella Contact Point Translation
Description	full extension to maximum flexion for participants with and without implants. Position of patellar contact point was determined by locating closest point to femur on patella throughout flexion. There are 2 patello-femoral contact points: 1 point on the medial aspect of the patella and 1 point on the lateral aspect of the patella. Throughout flexion, lateral contact point generally moves closer to the top of the patella (hence, the positive value for the results). The translation of this contact point is normalized to report a ratio between -1 and 1. The distance the point has traveled compared to the total height of the patella. For example, if the patella is 8 cm in height and the point travels approximately 2 cm upwards during flexion, the value would be reported as +2/8 = +0.25. Definition of normalized: "multiply (a series, function, or item of data) by a factor that makes the norm or some associated quantity such as an integral equal to a desired value (usually 1)."
Time Frame	Average post-operative time for LCS-PS group was 56 months. Average post-operative time for PS RP group was 55.7 months.

Outcome Measure Data

Analysis Population Description

Unit analyzed is an orthopaedic implant and subjects with normal knees do not have orthopaedic implants.

Arm/Group Title	Knee Prosthesis LCS PS RP TKA	Knee Prosthesis Sigma PS RP TKA	Control
Arm/Group Description	Subjects implanted with DePuy Low Contact Stress (LCS) Poster Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects implanted with a DePuy Sigma Posterior Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)	Subjects with normal knees
Measure Participants	10	10	10
Measure Implants/Knees	10	10	10
Mean (Standard Deviation) [ratio of patella height]	0.09 (.22)	.20 (.17)	.45 (.52)

Adverse Events

Adverse Event Reporting Description	There were no adverse effects or events encountered for any subjects in this study.
Arm/Group Title	Knee Prosthesis LCS PS RP TKA		Knee Prosthesis Sigma PS RP TKA		Control
Arm/Group Description	Subjects implanted with DePuy Low Contact Stress (LCS) Poster Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)		Subjects implanted with a DePuy Sigma Posterior Stabilizing (PS) Rotating Platform (RP) Total Knee Arthroplasty (TKA)		Subjects with normal knees
All Cause Mortality
	Knee Prosthesis LCS PS RP TKA		Knee Prosthesis Sigma PS RP TKA		Control
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	/ (NaN)		/ (NaN)		/ (NaN)
Serious Adverse Events
	Knee Prosthesis LCS PS RP TKA		Knee Prosthesis Sigma PS RP TKA		Control
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/10 (0%)		0/10 (0%)		0/10 (0%)
Other (Not Including Serious) Adverse Events
	Knee Prosthesis LCS PS RP TKA		Knee Prosthesis Sigma PS RP TKA		Control
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/10 (0%)		0/10 (0%)		0/10 (0%)

Limitations/Caveats

No adverse effects, events or unexpected risks occurred The sample size per group was small Age of the TKA groups were matched, the age of the normal subjects were not Cartilage thickness for normals had to be assumed as MRIs could not be obtained

More Information

Certain Agreements

All Principal Investigators ARE 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.