Mechanics Analysis of Patients Having a Sigma Mobile Bearing TKA

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

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT01714492

Acronym

Sigma MB TKA

Enrollment

Registered

2012-10-26

Start date

2012-04-30

Completion date

2012-11-30

Last updated

2019-10-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Knee Prosthesis, Knee Replacement Arthroplasty

Keywords

Total Knee Arthroplasty (TKA), in vivo mechanics, kinematics, fluoroscopy

Brief summary

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.

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.

Interventions

DEVICESigma Posterior Stabilizing Rotating Platform TKA Beaded Poly

Sigma PS RP TKA including a polyethylene insert with 4 beads

Study design

Observational model

COHORT

Time perspective

CROSS_SECTIONAL

Eligibility

Sex/Gender

ALL

Age

40 Years to 85 Years

Healthy volunteers

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

Design outcomes

Primary

Measure	Time frame	Description
In Vivo Linear Knee Kinematics From Fluoroscopy Evaluation During Deep Knee Bend Activity	10 yrs post-operative	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.
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

Measure	Time frame	Description
In Vivo Knee Force Values From Fluoroscopy Evaluation During Deep Knee Bend Activity	10 yrs post-operative	The intended unit of measure is times Body Weight (or xBW), relating to a ratio.
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	—

Countries

United States

Participant flow

Recruitment details

hospital, medical clinic

Participants by arm

Arm	Count
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.	8
Total	8

Baseline characteristics

Characteristic	Sigma Posterior Stabilizing Rotating Platform TKA Beaded Poly
Age, Categorical <=18 years	0 Participants
Age, Categorical >=65 years	7 Participants
Age, Categorical Between 18 and 65 years	1 Participants
Age, Continuous	74 years STANDARD_DEVIATION 8.6
Region of Enrollment United States	8 participants
Sex: Female, Male Female	6 Participants
Sex: Female, Male Male	2 Participants

Adverse events

Event type	EG000 affected / at risk
deaths Total, all-cause mortality	— / —
other Total, other adverse events	0 / 8
serious Total, serious adverse events	0 / 8