Analysis of Competitive Posterior Cruciate Retaining (PCR) and Posterior Stabilized (PS) Total Knee Arthroplasty (TKA)

Inclusion Criteria

• Subjects will have one of the following implant types: 1) Stryker Triathlon PCR TKA (28 subjects), 2) Stryker Triathlon PS TKA (28 subjects), 3) Zimmer Persona PCR TKA (28 subjects) and 4) Zimmer Persona PS TKA (28 subjects).
• Patients must be at least three months post-operative.
• Participants must not experience any pain or other post-operative complications.
• Participants must have a stable TKA and be capable of performing a deep knee bend activity.
• Participants must weigh less than 300 lbs., not underweight (BMI 35).
• Must be in the age range of 18 years to 85 years (both inclusive).
• Participants must be able to perform the required activities without concern.
• Subjects must be willing to sign the Informed Consent (IC) form to participate in the study.
• Patients who do not have previous surgery on the implanted knee that might restrict their movement.

Exclusion Criteria

• Pregnant, potentially pregnant, lactating females or of childbearing age. To satisfy radiation protocol, each female subject will be asked if she is pregnant, or possibly could be pregnant. A pregnant person will not be allowed to participate in the study. (All potential female study patients will be asked if they are premenopausal or if they have undergone a hysterectomy. If the possibility of pregnancy exists, a pregnancy kit will be given to the patient at the informed consent meeting, just prior to the fluoro. Results of the test will be recorded in a test log. Any female patient showing a positive test will be excluded from testing.)
• Subjects without the required type of knee implant.
• Cannot have pain in other parts of the body that would prohibit the subject from performing the activities).
• Cannot have ligamentous pain and/or laxity.
• Unwilling to sign IC/HIPAA form(s).
• Does not speak English.
• Patients who have enrolled in a fluoroscopic kinematic study within the past year.
• Patients currently involved in any personal injury litigation, medical/legal or worker's compensation claims.
• Patients with known drug or alcohol abuse histories or psychological disorders that could affect ability to complete all aspects of the study.
• Patients with neurological or musculoskeletal disorders that might adversely affect weight-bearing motion ability.