RSA of the ATTUNE Knee System: RCT Comparing Traditional Vs Enhanced-Fixation Device Designs

Radiostereometric Analysis (RSA) of the ATTUNE Knee System: A Randomized Controlled Trial Comparing Traditional Versus Enhanced-Fixation Device Designs

The principal objective of this study is to compare migration patterns between the Attune and Attune S+ PS knee systems 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, quantify changes in functional and health status of subjects following surgery and compare between study groups, and assess occurrences of complications following surgery.

This is a multi-centre, randomized controlled trial of patients undergoing posterior-stabilized total knee arthroplasty. In this study, the investigators propose to randomize 50 subjects to receive either the standard Attune PS TKA (n=25) or the enhanced fixation Attune S+ PS TKA (n=25) and follow them for a period of 2 years post-operatively. The primary outcome of the study will be stability of fixation of the tibial baseplate as measured by model-based RSA. Secondary outcomes will be to determine the functionality of patients after surgery using self-reported questionnaires.

The KRES is a patient reported questionnaire that consists of 19 questions. The questions ask how each expectation is important in the treatment of the knee. The scale is rated: 1 (Very important) to 5 (This does not apply to me). The score ranges from 19 to 95 with higher scores associated with higher expectations.

Evaluate and compare the change from preoperative to 2 years between the study groups timepoints in functional outcomes assessments. The EuroQol 5D 5L questionnaire is a standardized instrument for use as a measure of health outcome that is designed for completion by the subject.

Evaluate and compare the change from preoperative to 2 years between the study groups timepoints in patient reported satisfaction as measured using the visual analogue scale (VAS) from 0 (No pain) - 100 (Worst pain imaginable)

Evaluate and compare the change from preoperative to 2 years between the study groups timepoints in patient reported pain severity as measured using the visual analogue scale (VAS) from 0 (Unsatisfied) - 100 (Completely satisfied)

Evaluate and compare the change from preoperative to 2 years between the study groups timepoints in functional outcomes assessments, patient reported outcome

Evaluate and compare the change in UCLA activity score compared to baseline in the study cohort. UCLA activity scores range from 1 to 10, and is a measure of activity with 10 being most active.

The patient are asked to indicate the degree to which they have the above thoughts and feelings when they are experiencing pain. Each PCS item is rated on a 5-point scale: 0 (not at all) to 4 (all the time). The PCS total score is computed by summing responses to the 13 items. PCS total scores range from 0 - 52.

The Pre-surgical and/or Post-surgical Patient's Knee Implant Performance (PKIP) questionnaire is a patient reported questionnaire that consists of 24 questions relating to the patient's awareness of their knee. Questions include the patient's self-confidence about the current status of their knee performance, stability, and overall satisfaction. Each question has a 5, 6 or 10 Likaert- like response option.

Inclusion Criteria: Symptomatic osteoarthritis of the knee indicating primary total knee arthroplasty Between the ages of 21 and 80 inclusive Patients willing and able to comply with follow-up requirements and self-evaluations Ability to give informed consent Exclusion Criteria: Active or prior infection Medical condition precluding major surgery