"Anatomic patella design versus medialized dome design in the modern posterior stabilized (ATTUNE) total knee arthroplasty: a systematic review and meta-analysis".

BACKGROUND

Patellar component design in total knee arthroplasty (TKA) can influence patellofemoral kinematics and clinical outcomes. The medialized dome design (MDD) aligns the patella apex more medially, while the anatomic patella design (APD) aims to replicate the native patella's shape and tracking. Although biomechanical studies suggest potential benefits of APD, clinical evidence remains inconclusive.

METHODS

A systematic review and meta-analysis following PRISMA guidelines was conducted to compare the clinical outcomes of MDD and APD in a modern posterior-stabilized TKA (ATTUNE system). We searched PubMed, Scopus, Embase, and Web of Science on January 10, 2025, without language or date restrictions. Eligible studies included randomized controlled trials (RCTs) and comparative cohort designs evaluating patient-reported outcome measures (PROMs), revisions, complications, range of motion (ROM), and radiologic measures of patellar stability. Risk of bias was assessed using RoB-2 for RCTs and ROBINS-I for cohort studies. Pooled effect sizes were calculated using Hedges's g and random-effects modeling.

RESULTS

Seven studies, including three RCTs and four cohort studies, with a total of 1,069 patients and 1,113 knees (507 APD vs. 606 MDD), were included. The meta-analysis demonstrated no significant difference in PROMs (Hedges's g = 0.09; 95% CI [-0.04 to 0.22]; P = 0.17) or ROM (Hedges's g = 0.02; 95% CI [-0.21 to 0.26]; P = 0.83) between APD and MDD. While revision rates and complications were higher for APD, the differences were not statistically significant compared to MDD (14 vs 9). Radiographic measures showed inconsistencies and did not definitively favor either design.

CONCLUSIONS

Current evidence suggests that APD offers no clear clinical advantage over MDD in the ATTUNE posterior-stabilized TKA. Both designs yield broadly comparable PROMs and knee function outcomes. Larger RCTs with extended follow-up are warranted to clarify the safety of APD.

LEVEL OF EVIDENCE

III.