Trial Comparing Alignment Techniques - RSA of ATTUNE Knee System

Radiostereometric Analysis (RSA) of the ATTUNE Knee System: A Randomized Controlled Trial Comparing Anatomic (Femur First) to Neutral Mechanical Alignment Techniques

The purpose of this study is to compare migration patterns between mechanical and anatomic alignment surgical techniques for the Attune S+ CR-FB knee system using model-based RSA over the first 2 post-operative years.

This is a multi-centre, randomized controlled trial of patients undergoing cruciate-retaining total knee arthroplasty with the Attune S+ fixed bearing TKR system. Patients will be randomized to two study groups:

1. Neutral mechanical alignment;
2. Anatomical alignment.

The principal objective of this study is to compare migration patterns between mechanical and anatomic alignment surgical techniques for the Attune S+ CR-FB knee system using model-based RSA over the first 2 post-operative years.

Secondary objectives include; comparison of 2-year migration values against published thresholds for adequate short-term fixation, comparison of functional and health status of subjects following surgery, comparison of intra-operative soft-tissue releases, incidence of complications and adverse events, and to assess several health economic parameters relating to the surgery.

Inclusion Criteria:

1. Symptomatic osteoarthritis of the knee indicating primary total knee arthroplasty
2. Varus knee deformity of 0 to 10 degrees
3. Sufficient ligamentous function to warrant retention of the posterior cruciate ligament
4. Between the ages of 21 and 80 inclusive
5. Patients willing and able to comply with follow-up requirements and self-evaluations
6. Ability to give informed consent

Exclusion Criteria:

1. Active or prior infection
2. Medical condition precluding major surgery
3. Inflammatory arthropathy
4. Prior patellectomy
5. PCL deficiency
6. Major Coronal plane deformity
7. Valgus alignment
8. Bone defects requiring augments, cones and/or stemmed implants
9. Body Mass Index 45 or more