No difference in patient- reported outcomes with cruciate-retaining, anterior-stabilized, and posterior- stabilized total knee arthroplasty designs

<bold>Aims: </bold>This study compared patient-reported outcomes of three total knee arthroplasty (TKA) designs from one manufacturer: one cruciate-retaining (CR) design, and two cruciate-sacrificing designs, anterior-stabilized (AS) and posterior-stabilized (PS).<bold>Methods: </bold>Patients scheduled for primary TKA were included in a single-centre, prospective, three-armed, blinded randomized trial (n = 216; 72 per group). After intraoperative confirmation of posterior cruciate ligament (PCL) integrity, patients were randomly allocated to receive a CR, AS, or PS design from the same TKA system. Insertion of an AS or PS design required PCL resection. The primary outcome was the mean score of all five subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS) at two-year follow-up. Secondary outcomes included all KOOS subscales, Oxford Knee Score, EuroQol five-dimension health questionnaire, EuroQol visual analogue scale, range of motion (ROM), and willingness to undergo the operation again. Patient satisfaction was also assessed.<bold>Results: </bold>Patients reported similar levels of pain, function, satisfaction, and general health regardless of the prosthetic design they received. Mean maximal flexion (129 degrees (95% confidence interval (CI) 127 degrees to 131 degrees) was greater in the PS group than in the CR (120 degrees (95% CI 121 degrees to 124 degrees)) and AS groups (122 degrees (95% CI 120 degrees to 124 degrees)).<bold>Conclusion: </bold>Despite differences in design and constraint, CR, AS, and PS designs from a single TKA system resulted in no differences in patient-reported outcomes at two-year follow-up. PS patients had statistically better ROM, but the clinical significance of this finding is unclear.