Trial Outcomes & Findings for Mechanics Analysis of Patients Having a Sigma Mobile Bearing TKA (NCT NCT01714492)

NCT ID: NCT01714492

Last Updated: 2019-10-10

Results Overview

The values that were reported indicate the motion of the contact point from full extension to patient's maximum flexion. Throughout flexion, if the point translated forward (anteriorly) atop the tibial tray, the number was reported as positive. If the point traveled backwards (posteriorly) atop the tibial tray, the number was reported as negative.

• Recruitment status: COMPLETED
• Target enrollment: 8 participants
• Primary outcome timeframe: 10 yrs post-operative
• Results posted on: 2019-10-10

Participant Flow

hospital, medical clinic

Participant milestones

Measure	Sigma Posterior Stabilizing Rotating Platform TKA Beaded Poly subjects implanted with the Sigma Posterior Stabilizing Rotating Platform TKA including a polyethylene insert with 4 beads that allow for determination of polyethylene rotation.
Overall Study STARTED	8
Overall Study COMPLETED	8
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Mechanics Analysis of Patients Having a Sigma Mobile Bearing TKA

Baseline characteristics by cohort

Measure	Sigma Posterior Stabilizing Rotating Platform TKA Beaded Poly n=8 Participants subjects implanted with the Sigma Posterior Stabilizing Rotating Platform TKA including a polyethylene insert with 4 beads that allow for determination of polyethylene rotation.
Age, Categorical <=18 years	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	1 Participants n=5 Participants
Age, Categorical >=65 years	7 Participants n=5 Participants
Age, Continuous	74 years STANDARD_DEVIATION 8.6 • n=5 Participants
Sex: Female, Male Female	6 Participants n=5 Participants
Sex: Female, Male Male	2 Participants n=5 Participants
Region of Enrollment United States	8 participants n=5 Participants

PRIMARY outcome

Timeframe: 10 yrs post-operative

Population: Subjects implanted with the Sigma Posterior Stabilizing Rotating Platform TKA including a polyethylene insert with 4 beads that allow for determination of polyethylene rotation.

The values that were reported indicate the motion of the contact point from full extension to patient's maximum flexion. Throughout flexion, if the point translated forward (anteriorly) atop the tibial tray, the number was reported as positive. If the point traveled backwards (posteriorly) atop the tibial tray, the number was reported as negative.

Outcome measures

Measure	In Vivo Knee Kinematics From Fluoroscopy Evaluation During Dee n=8 Implants subjects implanted with the Sigma Posterior Stabilizing Rotating Platform TKA including a polyethylene insert with 4 beads that allow for determination of polyethylene rotation.
In Vivo Linear Knee Kinematics From Fluoroscopy Evaluation During Deep Knee Bend Activity Lateral Anterior Posterior Deep Knee Bend	-4.1 mm Standard Deviation 2.4
In Vivo Linear Knee Kinematics From Fluoroscopy Evaluation During Deep Knee Bend Activity Medial Anterior Posterior Deep Knee Bend	1.2 mm Standard Deviation 2.8

PRIMARY outcome

Timeframe: 10 yrs post-operative

Outcome measures

Measure	In Vivo Knee Kinematics From Fluoroscopy Evaluation During Dee n=8 Implants subjects implanted with the Sigma Posterior Stabilizing Rotating Platform TKA including a polyethylene insert with 4 beads that allow for determination of polyethylene rotation.
Femoral Axial Rotation With Respect to the Tibia During Deep Knee Bend Activity	6.1 degrees Standard Deviation 5.8

PRIMARY outcome

Timeframe: 10 yrs post-operative

Outcome measures

Measure	In Vivo Knee Kinematics From Fluoroscopy Evaluation During Dee n=8 Implants subjects implanted with the Sigma Posterior Stabilizing Rotating Platform TKA including a polyethylene insert with 4 beads that allow for determination of polyethylene rotation.
Range of Motion During Flexion of Deep Knee Bend Activity	103 degrees Standard Deviation 11.2

SECONDARY outcome

Timeframe: 10 yrs post-operative

Population: Subjects implanted with the Sigma Posterior Stabilizing Rotating Platform TKA including a polyethylene insert with 4 beads that allow for determination of polyethylene rotation

The intended unit of measure is "times Body Weight" (or xBW), relating to a ratio.

Outcome measures

Measure	In Vivo Knee Kinematics From Fluoroscopy Evaluation During Dee n=8 Implants subjects implanted with the Sigma Posterior Stabilizing Rotating Platform TKA including a polyethylene insert with 4 beads that allow for determination of polyethylene rotation.
In Vivo Knee Force Values From Fluoroscopy Evaluation During Deep Knee Bend Activity Medial Condyle Knee Force at Maximum Flexion	1.57 times body weight Standard Deviation 0.53
In Vivo Knee Force Values From Fluoroscopy Evaluation During Deep Knee Bend Activity Lateral Condyle Knee Force at Maximum Flexion	1.39 times body weight Standard Deviation 0.36

SECONDARY outcome

Timeframe: 10 yrs post-operative

Outcome measures

Measure	In Vivo Knee Kinematics From Fluoroscopy Evaluation During Dee n=8 Implants subjects implanted with the Sigma Posterior Stabilizing Rotating Platform TKA including a polyethylene insert with 4 beads that allow for determination of polyethylene rotation.
Condyle Contact Area at Maximum Flexion During Deep Knee Bend Activity Medial	109.16 mm^2 Standard Deviation 2.82
Condyle Contact Area at Maximum Flexion During Deep Knee Bend Activity Lateral	104.78 mm^2 Standard Deviation 21.22

SECONDARY outcome

Timeframe: 10 yrs post-operative

Outcome measures

Measure	In Vivo Knee Kinematics From Fluoroscopy Evaluation During Dee n=8 Implants subjects implanted with the Sigma Posterior Stabilizing Rotating Platform TKA including a polyethylene insert with 4 beads that allow for determination of polyethylene rotation.
Condyle Contact Stress at Maximum Flexion During Deep Knee Bend Activity Average Medial Condyle Contact Stress	10.66 MPa Standard Deviation 1.75
Condyle Contact Stress at Maximum Flexion During Deep Knee Bend Activity Average Lateral Condyle Contact Stress	10.05 MPa Standard Deviation 1.45

Adverse Events

Sigma Posterior Stabilizing Rotating Platform TKA Beaded Poly

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Richard Komistek, Ph. D.

The University of Tennessee

Phone: 8659744159

Email: rkomiste@utk.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place