Custom 3D-printed implants for severe acetabular bone loss in revision total hip arthroplasty: A review of current advances and future directions.

Abstract

Massive acetabular bone loss in revision total hip arthroplasty (rTHA) presents a major reconstructive challenge, particularly in Paprosky type III defects and pelvic discontinuity. Conventional reconstructive strategies, including biologic grafting, porous metal augments, and cup-cage constructs, may not adequately address complex three-dimensional (3D) defect morphology or achieve durable fixation in severe bone loss. This narrative review summarises current reconstruction strategies, with particular emphasis on the evolution, biomechanical principles, clinical outcomes, and future directions of custom 3D-printed acetabular implants. A literature search of PubMed, Google Scholar, and Embase (via Ovid) identified relevant clinical studies, systematic reviews, and registry analyses addressing reconstruction of severe acetabular defects using custom 3D-printed acetabular implants. Current evidence demonstrates favourable short- to intermediate-term clinical and radiographic outcomes, with reported implant survivorship of 95.8% at 3-6 years and 95% at 10 years in selected series. Compared with conventional modular reconstruction, custom 3D-printed acetabular implants improve conformity to complex defects, facilitate restoration of the hip centre of rotation, and optimise implant-bone contact and fixation. Reported complications are generally of lower rates comparatively, with postoperative dislocation, periprosthetic joint infection, and sciatic nerve palsy being the most frequently described adverse events, although the available evidence remains largely limited to retrospective case series with heterogeneous implant designs and relatively short follow-up. Two institutional cases are presented as illustrative examples of CT-based planning, custom implant manufacture, and surgical application in severe Paprosky type III acetabular defects. Custom 3D-printed acetabular implants represent an important advancement when conventional biologic and modular reconstruction techniques are insufficient. Future developments in artificial intelligence-assisted planning, robotic guidance, and sensor-enabled implants may further improve implant design, surgical precision, and postoperative monitoring; however, prospective comparative studies with longer follow-up are required to establish long-term durability and comparative effectiveness.