Thicker Polyethylene Bearings Offer Equivalent Patient-reported Outcomes

Polyethylene bearing (PEB) thickness in total knee arthroplasty (TKA) is a critical factor in achieving joint stability and soft-tissue balance. Despite long-standing surgical preference for thinner bearings, the effect of thicker PEBs on patient-reported outcomes (PROs) remains unclear. The purpose of this study was to compare patient-reported and surgical outcomes between patients receiving thicker (≥13 mm) and thinner (<13 mm) PEBs in primary TKA.

We retrospectively analyzed 2,751 patients who underwent primary TKA for osteoarthritis at a single high-volume orthopaedic hospital between 2020 and 2023. Patients were divided into two groups based on PEB thickness. Outcomes included PROs (Knee Injury and Osteoarthritis Outcome Score for Joint Replacement; Forgotten Joint Score), inpatient pain and mobility, surgical data, and 90-day postoperative complications. Multivariate statistical methods were used for analysis.

PEB thickness was not associated with clinically notable differences in PROs. At 6 and 12 months, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement and pain scores were slightly better in the ≥13-mm group (P < 0.05), but differences were not clinically meaningful. Subgroup analysis showed these differences were notable only in male patients. Forgotten Joint Scores and early complication rates were equivalent between groups.

The use of thicker PEBs (≥13 mm) in TKA does not negatively affect PROs or early surgical outcomes and may slightly improve midterm pain and function in male patients. These findings support the selective use of thicker bearings when required for intraoperative balance without compromising patient satisfaction or recovery.