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Completed

NCT Number: NCT01714492

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.

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Key information

Conditions

Knee Prosthesis Knee Replacement Arthroplasty

Age range

40 year–85 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Porter Adventist Hospital, Colorado Joint Replacement, Denver, Colorado, United States

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About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Sigma Posterior Stabilizing Rotating Platform TKA Beaded Poly

Device

Sigma PS RP TKA including a polyethylene insert with 4 beads

Primary outcomes

  1. In Vivo Linear Knee Kinematics From Fluoroscopy Evaluation During Deep Knee Bend Activity

    Time frame: 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.

  2. Femoral Axial Rotation With Respect to the Tibia During Deep Knee Bend Activity

    Time frame: 10 yrs post-operative

  3. Range of Motion During Flexion of Deep Knee Bend Activity

    Time frame: 10 yrs post-operative

Secondary outcomes

  1. In Vivo Knee Force Values From Fluoroscopy Evaluation During Deep Knee Bend Activity

    Time frame: 10 yrs post-operative

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

  2. Condyle Contact Area at Maximum Flexion During Deep Knee Bend Activity

    Time frame: 10 yrs post-operative

  3. Condyle Contact Stress at Maximum Flexion During Deep Knee Bend Activity

    Time frame: 10 yrs post-operative

Sponsors and collaborators

Lead sponsor

The University of Tennessee, Knoxville

Other

Collaborators

  • DePuy Orthopaedics

Registry information

Official study title

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

Acronym: Sigma MB TKA

Important dates

Study start
2012
Primary completion
2012
Study completion
2012
First posted
Oct 26, 2012
Registry last updated
Oct 10, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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