Clinical trial NCT01714492: Mechanics Analysis of Patients Having a Sigma Mobile Bearing TKA
Official title: In Vivo Mechanics Analysis of Patients Having a Sigma Mobile Bearing TKA
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Knee Prosthesis
Knee Replacement Arthroplasty
Keywords: Total Knee Arthroplasty (TKA)
in vivo mechanics
kinematics
fluoroscopy
Lead sponsor: The University of Tennessee, Knoxville
Sponsor class: OTHER
Collaborators: name: DePuy Orthopaedics
First posted: 2012-10-26
Enrollment: 8
Sex: ALL
Minimum age (years): 40
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: CROSS_SECTIONAL
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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: In Vivo Linear Knee Kinematics From Fluoroscopy Evaluation During Deep Knee Bend Activity
timeFrame: 10 yrs post-operative
measure: Femoral Axial Rotation With Respect to the Tibia During Deep Knee Bend Activity
timeFrame: 10 yrs post-operative
measure: Range of Motion During Flexion of Deep Knee Bend Activity
timeFrame: 10 yrs post-operative
Secondary outcomes:
measure: In Vivo Knee Force Values From Fluoroscopy Evaluation During Deep Knee Bend Activity
timeFrame: 10 yrs post-operative
measure: Condyle Contact Area at Maximum Flexion During Deep Knee Bend Activity
timeFrame: 10 yrs post-operative
measure: Condyle Contact Stress at Maximum Flexion During Deep Knee Bend Activity
timeFrame: 10 yrs post-operative
Other outcomes:
Locations:
city: Denver
country: United States
facility: Porter Adventist Hospital, Colorado Joint Replacement
state: Colorado
city: Knoxville
country: United States
facility: Perkins Hall, The University of Tennessee
state: Tennessee
city: Knoxville
country: United States
facility: Science and Engineering Research Facility, The University of Tennessee
state: Tennessee
Study officials:
affiliation: The University of Tennessee
name: Richard D Komistek, Ph. D.
role: PRINCIPAL_INVESTIGATOR
affiliation: Colorado Joint Replacement
name: Dennis A Douglas, MD
role: PRINCIPAL_INVESTIGATOR
References: