Evidence Hub

Peg Shearing as a Method of Failure in Highly Cross-Linked Polyethylene Patellar Components Used in Patellofemoral Arthroplasty

Pierce M, Leal J, Mills FB, Shah J, Bolognesi MP, Jiranek WA

Arthroplasty today, 2026

Abstract

Highly cross-linked polyethylene (HXLPE) is commonly used in knee arthroplasty due to its improved wear resistance. However, increased crosslinking reduces the tensile strength and fatigue resistance of polyethylene, which may be detrimental in high shear environments such as a cemented patellar button. In patellofemoral arthroplasty (PFA), patellar components are exposed to substantial shear stresses, which may predispose polyethylene components to fatigue-related failure and peg shear. We report a case series of patellar component failures in PFA, including several HXLPE patellar buttons demonstrating peg fracture and loosening, as well as 1 ultra-high molecular weight polyethylene patellar button with a similar failure pattern. To our knowledge, these represent the first reported cases of HXLPE patellar component peg shear in PFA, a complication previously described only in the setting of total knee arthroplasty.

How strong is the evidence?

Evidence Hub reads this as a case series, done in people. Its evidence level is 5 of 5 (Very low · case / narrative / animal / in vitro / in silico). Case reports, narrative reviews, and animal, cell or computer-model studies give the weakest evidence for human health.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free