# Patellar resurfacing as a prognostic variable in total knee arthroplasty: a two‑decade retrospective cohort (2000‑2020)

## TL;DR

This study found that patellar resurfacing during knee replacement surgery reduces pain and loosening risks without increasing overall revision rates.

## Contribution

The study provides long-term evidence supporting selective patellar resurfacing over routine use in knee arthroplasty.

## Key findings

- Patellar resurfacing reduced anterior knee pain by 83% compared to non-resurfacing.
- Resurfacing lowered aseptic loosening risk by 7.5% without increasing revision rates.
- No significant difference in overall revision rates between resurfaced and non-resurfaced groups.

## Abstract

The impact of patellar resurfacing (PR) on long-term outcomes following primary total knee arthroplasty (TKA) remains a topic of debate.

This study examined a retrospective cohort of 334 primary total knee arthroplasties (TKAs) performed between 2000 and 2020 at a specialized hospital. The surgeries were conducted from January 2000 to December 2020, allowing for a maximum potential follow-up period of 20 years. The primary endpoint assessed was the rate of any-cause revision. Secondary endpoints included anterior knee pain, aseptic loosening, patient-reported outcomes (Western Ontario and McMaster Universities Osteoarthritis index and Oxford Knee Score), and complications. Kaplan-Meier estimates and multivariable Cox models, adjusted for age, body mass index, and inflammatory arthropathy, were utilized.

PR yielded an absolute risk reduction (ARR) of 83% for anterior knee pain (2.2% in the PR group vs. 85.2% in the WPR group; number needed to treat ≈ 1–2) and an ARR of 7.5% for aseptic loosening (4.4% vs. 11.9%; NNT = 14). The overall revision rates were 5.1% for PR and 6.7% for WPR, demonstrating no significant differences (hazard ratio 0.65, 95% confidence interval 0.30–1.42).

Patellar resurfacing significantly alleviates anterior knee pain and decreases the risk of aseptic loosening without raising the overall revision rate. These findings advocate for a selective resurfacing approach targeting patellae at a higher risk of pain rather than adopting a routine or universal resurfacing strategy.

Not applicable, this study is an observational retrospective cohort; no prospective registration was required.

The online version contains supplementary material available at 10.1186/s12891-025-09076-y.