Cement or press-fit? Impact of patellar fixation technique on outcomes after primary TKA: a systematic review.

Introduction: The optimal fixation technique for patellar components in primary total knee arthroplasty (TKA); cemented versus press-fit, remains controversial. While early press-fit designs were associated with complications, second-generation implants with improved osseointegration features have renewed interest in cementless fixation.

Methods: This systematic review included studies comparing cemented and press-fit patellar fixation in primary TKA. A comprehensive literature search identified 202 studies, of which eight met predefined inclusion criteria. Data were extracted on survivorship, revisions, complications, and patient-reported outcome measures (PROMs).

Results: Across 1666 knees, survivorship was comparable between cemented and press-fit groups. Several studies reported 100% short-term survivorship in cementless cohorts. Four studies identified statistically significant PROM differences, but findings were inconsistent and context-dependent. No clear advantage was found for either fixation type in terms of overall pain, function, or satisfaction. Cementless patellae demonstrated no increased risk of aseptic loosening or patellar fracture. Complications were infrequent and more often reported in cemented groups.

Discussion: These findings showed no significant difference in failure or PROMs between fixation methods. While surgical preference remains a driver of implant choice, current evidence does not support a universal superiority of one fixation method over the other.