Last reviewed: September 29, 2026

Either way can work well, and the choice is mostly your surgeon’s.

In a knee replacement, the underside of the kneecap can be covered with a plastic button, called resurfacing, or left as it is. In the largest trial, with more than 1,700 people, results five years later were the same either way. According to the American Academy of Orthopaedic Surgeons, there is no difference between the two.

When many trials are pooled, some differences appear. Resurfacing led to somewhat less pain at the front of the knee and fewer repeat operations, while overall function came out about the same. The advantage shows up mainly with older implant designs. With modern implants shaped to suit an unresurfaced kneecap, it largely disappears.

National joint registries lean the same way. In two large registries, knees without resurfacing were redone somewhat more often for more than half of the implants studied, with no difference for most of the rest.

Kneecap fracture after resurfacing is rare, and no more common than without it.

If pain at the front of the knee continues, the kneecap can be resurfaced later, but this helps only about half of people.

Practice differs widely between countries. Most knees in the United States are resurfaced, while few are in Norway or Sweden. Evidence for specific groups, such as people with rheumatoid arthritis, is limited.

In general:

  • Ask your surgeon whether they usually resurface the kneecap, and why.
  • Ask which implant they plan to use.
  • Pain at the front of the knee that does not settle is worth reporting.

Drafted with AI assistance from published sources, reviewed and edited by Babak Sheikh, MD.

Sources:

  • American Academy of Orthopaedic Surgeons. Surgical Management of Osteoarthritis of the Knee: Evidence-Based Clinical Practice Guideline. 2022. https://www.aaos.org/globalassets/quality-and-practice-resources/surgical-management-knee/smoak2cpg.pdf
  • Breeman S, et al. Patellar Resurfacing in Total Knee Replacement: Five-Year Clinical and Economic Results of a Large Randomized Controlled Trial. J Bone Joint Surg Am. 2011. https://doi.org/10.2106/JBJS.J.00725
  • Grela M, et al. Clinical Effectiveness of Patellar Resurfacing, No Resurfacing and Selective Resurfacing in Primary Total Knee Replacement: Systematic Review and Meta-Analysis of Interventional and Observational Evidence. BMC Musculoskelet Disord. 2022. https://doi.org/10.1186/s12891-022-05877-7
  • Tang X, et al. Patellar Resurfacing in Primary Total Knee Arthroplasty: A Meta-analysis and Trial Sequential Analysis of 50 Randomized Controlled Trials. Orthop Surg. 2023. https://doi.org/10.1111/os.13392
  • Simpson CJ, et al. Patellar Resurfacing Was Not Associated With a Clinically Significant Advantage When a Modern Patellar Friendly Total Knee Arthroplasty Is Employed: A Systematic Review and Meta-Analysis. The Knee. 2023. https://doi.org/10.1016/j.knee.2023.01.021
  • Ross BJ, et al. Do Implant-Specific Associations Exist Between Patellar Resurfacing and All-Cause Revision Risk After Primary Total Knee Arthroplasty? A Retrospective Analysis of Two National Joint Registries. J Arthroplasty. 2026. https://doi.org/10.1016/j.arth.2025.11.016
  • Harris AB, et al. Is Patella Resurfacing Associated With Postoperative Extensor Mechanism Disruption After Total Knee Arthroplasty? A Systematic Review and Meta-Analysis. J Arthroplasty. 2025. https://doi.org/10.1016/j.arth.2025.02.059
  • Andronic O, et al. What Are the Outcomes of Secondary Patella Resurfacing for Dissatisfaction Following Primary Knee Arthroplasty? A Systematic Review and Meta-Analysis of 604 Knees. J Arthroplasty. 2024. https://doi.org/10.1016/j.arth.2023.10.027
  • Fraser JF, Spangehl MJ. International Rates of Patellar Resurfacing in Primary Total Knee Arthroplasty, 2004-2014. J Arthroplasty. 2017. https://doi.org/10.1016/j.arth.2016.06.010

This is general information about what published research shows. It is not medical advice and it is not about your situation. Reading it does not create a doctor-patient relationship with me. I am a retired orthopedic surgeon and I do not see patients. Talk with your own doctor before changing anything about your care. If something feels suddenly or seriously wrong, get medical care promptly rather than waiting.

This page is provided as is. I make no guarantee that it is accurate, complete or current, and medical evidence changes. Use of it is at your own risk.

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