Detection of simulated complications in all-polymer PEEK knee prostheses: a cadaveric imaging study using...

All-polymer polyetheretherketone (PEEK) knee prostheses are being developed as an alternative to metal implants, offering benefits like bone-like elasticity, wear resistance, and the absence of clinically relevant metal artefacts on imaging. Their radiological characteristics and complications have not been systematically studied. This study describes the imaging features of a new all-polymer PEEK knee prosthesis and assesses the detection of simulated complications with radiography, computed tomography (CT), and magnetic resonance imaging (MRI) in cadaver models.

The study followed Article 68, paragraph 1 of the Dutch Civil Code for the lawful use of human cadaver material, and all procedures met institutional and national ethical guidelines. Four cadaveric lower limbs were implanted with cemented PEEK knee prostheses (PEEK femoral and polyethylene tibial components). Radiography, CT, and MRI were used to evaluate both typical postoperative findings and four simulated complications: prosthesis loosening, cement fracture, implant migration, and prosthesis fracture. An experienced fellowship-trained musculoskeletal radiologist assessed the visibility and diagnostic characteristics of each complication.

The prostheses were clearly visible across all imaging modalities, allowing reliable assessment of the implant-cement-bone interface without relevant metal artefacts. Cement fractures were detected on all radiographs, though visibility varied by projection. CT distinguished PEEK and polyethylene based on radiodensity and provided the most complete structural overview of all simulated complications. T2-weighted MRI was the most sensitive modality for detecting fluid at the implant-cement interface and identifying interface separation.

All-polymer PEEK knee prostheses demonstrate favourable imaging characteristics in a cadaveric setting, without any clinically relevant metal-related artefacts and with good visibility of simulated implant complications across radiography, CT, and MRI. These findings suggest potential imaging advantages for future clinical follow-up of polymer-based implant systems, although direct comparative clinical studies are required for confirmation.