Custom Pelvic Implants in Complex Total Hip Arthroplasty.

Severe acetabular bone loss and pelvic discontinuity in revision total hip arthroplasty present substantial reconstructive challenges, particularly when standard hemispherical cups, augments, or cages cannot achieve durable fixation or restore appropriate hip biomechanics. Custom pelvic implants (CPIs) are designed from patient-specific CT data and produced using additive manufacturing to create monoblock constructs that conform to bony defects and maximize fixation to remaining viable bone. This review summarizes the evolution of CPIs from early "triflange" devices to contemporary porous-coated, biomechanically optimized designs and outlines current nomenclature and indications. Key elements of preoperative evaluation, imaging protocols, and CT-based modeling are reviewed, along with implant design considerations including flange geometry, ischial fixation strategies, and screw trajectory planning. Surgical techniques for managing pelvic discontinuity are discussed with emphasis on achieving construct stability and promoting osseointegration. Published midterm to long-term outcomes demonstrate high implant survivorship, improved function, and low mechanical failure rates, with most revisions attributable to infection or instability. Economic analyses suggest CPIs are cost-comparable with other advanced reconstructive options while offering reliable fixation in complex cases. When applied with appropriate patient selection, careful design collaboration, and meticulous surgical execution, CPIs provide an effective and reproducible strategy for challenging acetabular reconstruction.