Comparison of the clinical efficacy of patellar lateral retraction and patellar eversion in total knee arthroplasty: a systematic review and meta-analysis

Background According to the mobilization technique of the intraoperative patella, total knee arthroplasty (TKA) can be categorized into patellar eversion (PE) and patellar lateral retraction (PLR). Comparisons between the two procedures are inconclusive; therefore, the study purpose was to assess the postoperative clinical efficacy to identify the most suitable procedure. Methods Electronic databases were searched, including Web of Science, ScienceDirect, PubMed, Embase, OVID, the Cochrane Library, CINAHL, CNKI, and WANFANG, to identify clinical trials of PLR versus PE from inception to May 2023. The statistical software Stata 15.0 and Review Manager 5.4 were applied to the data analysis. Results Fifteen studies evaluating a total of 1349 patients and 1409 knees were ultimately included. Statistically significant differences emerged between the PLR and PE groups with respect to blood loss (P = 0.02), incision length (P < 0.001), operation time (P = 0.01), straight leg raise (P < 0.001), knee range of motion (ROM; P < 0.05), the Knee Society Score (KSS) functional score (P = 0.0003), the visual analogue scale (VAS) score (1 and 3 months, both P < 0.05), and operative complications (P = 0.02). Furthermore, the PLR and PE groups had similar clinical efficacy in terms of quadriceps strength, VAS score (1 week and 1 year), Hospital for Special Surgery score, KSS pain score, Insall-Salvati ratio, and the occurrence of patella baja (all P >= 0.05). Conclusions The PLR procedure is superior to PE in terms of blood loss, incision length, straight leg raise, knee ROM, VAS score (1 and 3 months), KSS functional score, and operative complications, although PE could decrease the operation time. PLR could achieve better postoperative clinical outcomes than could PE. Therefore, it is recommended that experienced surgeons prioritize PLR in TKA.