Cemented Versus Press-Fit Patellar Implants in Primary Total Knee Arthroplasty: Systematic Review and Meta-Analysis.

BACKGROUND

Modern press-fit patellar components (PFP) for total knee arthroplasty (TKA) are becoming more popular as the technology has improved, and studies have shown comparable survivorship with potential advantages such as decreased operative time and biologic fixation. However, there is a paucity of large, high-quality studies comparing survivorship and failure rates of PFP versus cemented patellar components (CPs). The purpose of this systematic review and meta-analysis was to examine the survivability of CP compared to PFP components in terms of all-cause, aseptic loosening, and patellar fracture failure in primary TKA. We hypothesized that these operative modalities would have similar survivorship.

METHODS

A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for PubMed and EMBASE databases. Case reports, review articles, < years years of follow-up, and studies involving revision arthroplasty were excluded. T-tests evaluated differences in age, body mass index, sex, and Knee Society Score between PFP and CP in primary TKA. Relative risk ratios were calculated to examine possible significant differences in survivorship between press-fit versus CP modalities.

RESULTS

A total of 25 studies (31,757 knees) met the inclusion criteria. These articles were published between 1991 and 2024 and included 3,385 PFPs and 28,372 CPs. The mean follow-up time, age, and body mass index were 8.4 years, 65 years, and 31.0, respectively. Patients receiving CP and PFP differed only in age (67 years versus 63 years, P = 0.013). There was no difference in survivability between PFP and CP for either aseptic loosening, patellar fracture, or all-cause failure as end points (all-cause failure, two-arm analysis P = 0.20).

CONCLUSIONS

Modern PFPs have similar survivorship when compared to CP designs. However, there are few high-level studies investigating PFP. Future prospective, randomized trials should be conducted to further examine survivorship, risk of adverse events, and outcomes between PFP and CP.