Anterior Referencing versus Posterior Referencing in Primary Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials

(1) Background: The purpose of this study was to perform a systematic review and meta-analysis of studies comparing clinical and radiographic outcomes between anterior referencing (AR) and posterior referencing (PR) systems in total knee arthroplasty (TKA). (2) Methods: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, MEDLINE, Scopus, and Cochrane Central databases were searched in August 2022. Data extracted for quantitative analysis included the Knee Society Score (KSS), the Western Ontario and McMaster University (WOMAC) index, knee ROM, posterior condylar offset (PCO), and the posterior condylar offset ratio (PCOR). The methodological quality of the included studies was assessed using the Modified Newcastle-Ottawa Quality Assessment. Randomized controlled trials were assessed with version 2 of the risk of bias tool (RoB2), recommended by the Cochrane Collaboration. (3) Results: For the meta-analysis, five comparative studies met the eligibility criteria. There were 584 patients in all, 294 of whom had AR TKA and 290 of whom had PR TKA. Three studies with 181 and 179 cases in the AR and PR groups, respectively, had reported preoperative KSS. A statistically significant difference was found favoring the PR group. (p = 0.01). The same cases' postoperative range of motion was documented, and a statistically significant difference was discovered in favor of the AR group. Postoperative PCO was described in four studies in 243 and 241 cases in the AR and PR TKA groups, respectively, and a statistically significant difference was found with a higher postoperative PCO in the PR group (p = 0.003). Postoperative PCOR was calculated in two studies in the same cases in the AR and PR TKA groups and a statistically significant difference was found with a higher postoperative PCOR in the PR group (p = 0.002). (4) Conclusion: Anterior referencing for TKA may result in improved knee ROM postoperatively, while posterior referencing may produce larger PCO and PCOR on postoperative imaging. However, no significant differences were noted in clinical outcomes between the AR and PR groups at final follow-up.