The presence of cement pockets on the tibial component undersurface is associated with reduced revision for aseptic tibial loosening—A single‐centre study of 11,594 total knee arthroplasties

PURPOSE: Aseptic loosening (AL) remains the most common cause of revision surgery in primary total knee arthroplasty (TKA). Numerous mechanisms to explain the underlying process of AL have been proposed, with tibial implant design thought to influence rates of failure. Tibial baseplates vary in design. The incorporation of a recessed area at the implant-cement interface of the tibial baseplate, a 'cement pocket', may decrease revision for aseptic tibial loosening (ATL). In this study, we assess the effect of such cement pockets on rates of revision for ATL across multiple implant designs. METHODS: We analysed 11,594 consecutive primary cemented total knee arthroplasties (TKAs) performed between April 2003 and December 2023 with a minimum 2-year follow-up. The use of mobile bearing (MB) or fixed bearing (FB) tibial implants and the presence or absence of cement pockets were noted. Revisions and the revision indication were identified using our local database and the National Joint Registry (NJR). Statistical analysis was undertaken to assess the effect of the presence of cement pockets and the tibial articulation (FB or MB) on the rates of all-cause revision as well as revision for ATL. RESULTS: We identified 8591 FB-TKAs; of these, 4753 tibial components incorporated cement pocket design and 3838 did not. There were 3003 MB-TKAs, of which 942 had cement pockets, and 2061 did not. The presence of cement pockets made no significant difference to all-cause revision (ACR) (p = 0.67). Cement pockets did significantly reduce the revision rate for ATL for the whole cohort (p < 0.01) and for FB-TKAs (p < 0.01) but not for MB-TKAs (p = 0.25). CONCLUSIONS: The presence of cement pockets appears to reduce the risk of revision for AL. LEVEL OF EVIDENCE: Level III.