Is Point of Care Three-Dimensional Printing of Polyaryletherketone Triflange Cups Feasible for Revision Total Hip Arthroplasty?

Abstract

Background Titanium three-dimensional (3D) printed triflange cups are an established treatment option for severe pelvic discontinuity, but are costly and, when produced offsite, involve weeks of surgical delay. Three-dimensional printing of polyetheretherketone (PEEK) at the point of care (POC) has recently been 510(k) cleared by the Food and Drug Administration for cranioplasty to reduce implant cost and time to treatment. We asked in this pilot study whether 3D-printed triflange cups from high-strength polyaryletherketone (PAEK) polymers like PEEK could be produced with sufficient strength for revision total hip arthroplasty and whether annealing could improve cup strength. Methods For proof-of-concept, two representative triflange cup designs were developed based on a set of 49 full-body computed tomography scans from the public New Mexico Decedent Image Database repository. The triflange cups (n = 3 per design) were additively manufactured using an industrial 3D printer (F421) and AM 200 PAEK filament. A second set of cups (n = 3 per design) was annealed in an effort to improve strength. A customizable fixture was developed for mechanical testing of the personalized cups, which were loaded to failure in an MTS load frame. Results As-printed (nonannealed) polymer cups failed due to deformation followed by layer separation, whereas the annealed cups fractured. The ultimate load (mean ± SD) for the two nonannealed triflange cup designs was 10.2 ± 0.02 kN and 11.0 ± 1.9 kN, respectively. After annealing, the strength of the two designs was 2.60 ± 0.44 kN and 10.5 ± 2.7 kN. Conclusions The nonannealed PAEK cups exceeded the strength published for a titanium 3D-printed design (5.4 kN). The promising results of this pilot study demonstrate proof-of-concept and suggest that PAEK polymers such as PEEK may be suitable biomaterials for future triflange cup applications. Additional research is needed to incorporate porosity into the printed designs and further refine the mechanical test model.