3DP Acetabular PSG for Cup Placement in THR

In this case series, patient-specific guides (PSG) based on 3D reconstruction and printed PSG were designed to assist in locating the optimal placement for an acetabular cup in THR. The study aims to determine whether PSG can help orientate an ideal acetabulum in anatomical deranged acetabula during THR. We hypothesize that implementing 3D preoperative plans using PSG will most accurately approximate the acetabulum for acetabular cup implantation. The pelvises of four patients were imaged and reconstructed with computed tomography (CT). The angle of lateral opening (ALO), angle of inclination and version were calculated by means of computer-aided (CAD) image analysis. PSG was 3D printed matching the acetabular orientation preoperatively planned and used to direct acetabular reaming tools. Acetabular cup alignment and implantation were performed with PSG. The coefficient of variation was measured by comparing the pre-and postoperative values measured from CT. Preoperatively planned cup orientation closely measured final cup placement. In this study, 3D-printed acetabular PSG has shown promising results in precisely matching the surface and the unique anatomy of the distorted acetabula. Without the use of hip positioning guides set at reference values for ALO and version angles, we concluded that using the guides produced from the patient’s specific anatomy, provided the optimal result for maintaining the rotation centre within the acetabulum. While PSG offers advantages in accurately recreating hip anatomy and optimizing implant placement, challenges such as the learning curve and increased costs must be considered.

 

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Publication History

Article published online:
15 July 2025