Mechanics Analysis of Patients Having a Sigma Mobile Bearing TKA (Sigma MB TKA)

In Vivo Mechanics Analysis of Patients Having a Sigma Mobile Bearing TKA

Utilize previously developed mathematical model to determine in vivo knee mechanics (kinematics, forces, stresses, areas and sound) for subjects having a Sigma Posterior Stabilizing (PS) mobile bearing (MB) total knee arthroplasty (TKA). There are several hypotheses for this study, although the most prominent is: Subjects having a Sigma RP PS TKA will experience polyethylene bearing rotation at 10 years post-operative, similar to their previous evaluations at six months, two years and five years.

Study Overview

• Status: Completed
• Conditions: Knee Replacement Arthroplasty; Knee Prosthesis
• Intervention / Treatment: Device: Sigma Posterior Stabilizing Rotating Platform TKA Beaded Poly

Detailed Description

Additional hypotheses:

• Subjects having a Sigma RP PS TKA will experience full ideal femorotibial contact mechanics.
• Subjects having a Sigma RP PS TKA will experience optimal cam/post mechanics.
• Subjects having a Sigma RP PS TKA will experience continuous axial rotation in deep flexion.
• Subjects having a Sigma RP PS TKA will experience optimal distribution of tibio-femoral and cam/post contact forces over a broad area on the post.
• Subjects having a Sigma RP PS TKA will experience a smooth transition of the cam on the post, not an abrupt slide as seen with fixed bearing PS TKA.
• The use of the sound sensors will detect cam/post contact mechanics under in vivo conditions.

• Study Type: Observational
• Enrollment (Actual): 8

Contacts and Locations

Study Locations

• United States
  • Colorado
    • Denver, Colorado, United States, 80210
      • Porter Adventist Hospital, Colorado Joint Replacement
  • Tennessee
    • Knoxville, Tennessee, United States, 37996
      • Perkins Hall, The University of Tennessee
    • Knoxville, Tennessee, United States, 37996
      • Science and Engineering Research Facility, The University of Tennessee

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Patients are eight mobile bearing subjects that were implanted over 10 years ago with a custom polyethylene insert that has four beads rigidly inserted into the polyethylene component.

Description

Inclusion Criteria:

• At least six months post-operative
• Between 40-85 years of age
• Have a body weight of less than 250 lbs.
• Judged clinically successful with a AKS greater than 90
• Have the DePuy Sigma mobile bearing TKA
• Good-to-excellent post-operative passive flexion
• Must be willing to sign the IC and HIPAA forms.

Exclusion Criteria:

• Pregnant females
• Those not willing to sign the IC and HIPAA forms

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
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	Device: Sigma Posterior Stabilizing Rotating Platform TKA Beaded Poly; Sigma PS RP TKA including a polyethylene insert with 4 beads

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
In Vivo Linear Knee Kinematics From Fluoroscopy Evaluation During Deep Knee Bend Activity	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.	10 yrs post-operative
Femoral Axial Rotation With Respect to the Tibia During Deep Knee Bend Activity		10 yrs post-operative
Range of Motion During Flexion of Deep Knee Bend Activity		10 yrs post-operative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
In Vivo Knee Force Values From Fluoroscopy Evaluation During Deep Knee Bend Activity	The intended unit of measure is "times Body Weight" (or xBW), relating to a ratio.	10 yrs post-operative
Condyle Contact Area at Maximum Flexion During Deep Knee Bend Activity		10 yrs post-operative
Condyle Contact Stress at Maximum Flexion During Deep Knee Bend Activity		10 yrs post-operative

Collaborators and Investigators

• Sponsor: The University of Tennessee, Knoxville
• Collaborators: DePuy Orthopaedics
• Investigators: Principal Investigator: Richard D Komistek, Ph. D., The University of Tennessee; Principal Investigator: Dennis A Douglas, MD, Colorado Joint Replacement

Study record dates

Study Major Dates

• Study Start: April 1, 2012
• Primary Completion (Actual): November 1, 2012
• Study Completion (Actual): November 1, 2012

Study Registration Dates

• First Submitted: October 23, 2012
• First Submitted That Met QC Criteria: October 25, 2012
• First Posted (Estimate): October 26, 2012

Study Record Updates

• Last Update Posted (Actual): October 10, 2019
• Last Update Submitted That Met QC Criteria: October 8, 2019
• Last Verified: October 1, 2019

More Information

Terms related to this study

• Keywords: Total Knee Arthroplasty (TKA); kinematics; fluoroscopy; in vivo mechanics
• Other Study ID Numbers: 11019 (Other Identifier: Fred Hutch/University of Washington Cancer Consortium); R01 1373 424 (Other Identifier: The University of Tennessee)