IMPROVED EARLY FUNCTIONAL OUTCOME WITH THE ATTUNE TOTAL KNEE REPLACMENT: A PROPENSITY SCORE MATCHED TRIAL

Introduction: The Attune total knee replacement (TKR) is a recent design of TKR, one of its aims was to lower incidence of anterior knee pain compared to the press fit condylar (PFC) Sigma. Whether this translates into improved patient reported outcome measures remains unknown. The primary aim compared the functional outcome, measured by the Knee Society Knee Score (KSKS), at one year between patients receiving an Attune TKR with those receiving a PFC Sigma TKR. Secondary aims assessed improvement in the Knee Society Functional Score (KSFS), generic health (Short Form-12 score), range of movement (ROM), and length of stay (LOS) between the two groups. Methods:The study was powered for 67 patients in each group. Prospective data was collected on patients receiving either implant over a two-year period. Propensity score matching for age, gender, BMI, comorbidity, pre-operative function, and radiographic severity was performed. Results: There was significant improvement in the KSKS in both groups (p<0.001), however the Attune group demonstrated a significantly greater improvement in the KSKS (difference 8.4, 95% confidence intervals (CI) 0.1 to 16.7, p=0.049). There was no difference in the KSFS (95% CI -2.7 to 8.8, p=0.3), Short Form-12 physical component (95% CI -0.9 to 3.4, p=0.25), or ROM (95% CI -1.7 to 5.6, p=0.3). LOS was significantly reduced in the Attune group (difference 1.2 days, 95% CI 0.5 to 1.9, p<0.001). Conclusions: Results from this study demonstrate the Attune TKR offers a greater improvement in knee specific function at one year compared with the PFC Sigma TKR.