In Vivo Kinematics Comparison of Stryker or Zimmer TKA

A better understanding of knee joint kinematics is important to explain premature
polyethylene wear failures within knee implants and to help design a prosthesis that most
closely approximates the normal knee. Therefore, the objectives for this study are to
compare the in vivo kinematic patterns for subjects implanted with either a Stryker
Triathlon CR total knee arthroplasty (TKA) or Zimmer PCR TKA design to determine if there
are any kinematic differences between these TKA designs and to compare the sounds emitted
from each kind of implant during activities. Each subject will be asked to undergo a
fluoroscopic evaluation while performing weight-bearing activities under surveillance using
the University of Tennessee's new mobile tracking fluoroscopic unit while wearing sound
sensors to correlate the sounds emitted from the implanted knees with the movements while
performing activities. The mobile fluoroscopy unit is approved for use by the State of
Tennessee on a study-by-study basis after IRB approval is obtained for each study.

Inclusion Criteria:

- Must be at least 3 months post-operative with no other surgical procedures conducted
within the past 6 months

- Must have body weight of less than 250 lbs

- Must have Body Mass Index of less than 38

- Must be judged clinically successful with a Knee Society Score >90

- Must have 100% post-operative passive flexion with no ligamentous laxity or pain

- Must be able to walk on level ground without aid of any kind

- Must be able to ascend and descend a ramp with a 10 degree incline with no assistance

- Must be willing to sign both Informed Consent and HIPAA forms

- Must be between 160 cm (5'3) and 193 cm (6'4) tall

Exclusion Criteria:

- Pregnant or potentially pregnant females

- Unwilling to sign Informed Consent or HIPAA forms