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

The University of Tennessee, Knoxville

Status: Completed

Conditions: Knee Replacement Arthroplasty; Knee Prosthesis

Treatments: Device: Sigma Posterior Stabilizing Rotating Platform TKA Beaded Poly

Study type: Observational

Funder types: Other; Industry

Identifiers

NCT01714492

11019 (Registry Identifier)

R01 1373 424 (Other Identifier)

Details and patient eligibility

About

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.

Full 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.

Enrollment: 8 patients

Sex: All

Ages: 40 to 85 years old

Volunteers: No 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

Trial design

8 participants in 1 patient group

Sigma Posterior Stabilizing Rotating Platform TKA Beaded Poly

Description:

subjects implanted with the Sigma Posterior Stabilizing Rotating Platform TKA including a polyethylene insert with 4 beads

Treatment:

Device: Sigma Posterior Stabilizing Rotating Platform TKA Beaded Poly