Reconstruction of Paprosky Type III Acetabular Defects by Three-Dimensional Printed Porous Augment: Techniques and Clinical Outcomes of 18 Consecutive Cases.

Abstract

ObjectiveTo introduce the surgical technique of reconstruction of Paprosky type III acetabular defects by 3D printed porous augments.MethodsFirst, CT scans of pelvis were obtained to establish the 3D reconstruction model of 3D printed porous augment. Then, a nylon pelvis model was printed to simulate operation with the surgeons. At this time, the augment was designed and modified according to the surgeon's suggestions and the 3D printing principles. Eighteen patients with Paprosky type III acetabular defects receiving reconstructive surgery by 3D printed porous augments were included in current study. Their data, including general information, intra‐operative findings, imaging results, functional scores, and complications were retrospectively analyzed.ResultsThe mean follow‐up time lasted 33.3 ± 2.0 (24–56) months. The average limb‐length discrepancy (LLD) was 31.7 ± 4.2 (3–59) mm preoperatively, 7.7 ± 1.4 (1–21) mm postoperatively (P < 0.0001), and 7.5 ± 1.2 (0–18) mm at the latest follow‐up. The mean vertical position of hip center of rotation (HCOR) from the interteardrop line changed from preoperative 50.7 ± 3.9 (23.3–75.3) mm to postoperative 22.9 ± 1.9 (10.1–40.3) mm (P < 0.0001), with the latest follow‐up revealing an HCOR of 22.3 ± 1.7 (11.0–40.5) mm. Follow‐up study showed that no hip had radiolucencies and radiological loosening of the acetabular components and augment. The average Harris hip score (HHS) improved from 40.3 ± 4.5 (10.5–71) before operation to 88.4 ± 1.9 (75–97) at the last follow‐up (P < 0.0001). Moreover, follow‐up exhibited that no periprosthetic joint infection, hip dislocation, fracture, and re‐revision occurred.ConclusionSurgical treatment of Paprosky type III acetabular defect with 3D printed porous augment was simple, achieved good match between porous augment and the defect bone surface and the acetabular component, ideally restored LLD and HCOR after operation, significantly improved HHS and attained good early clinical outcomes. It is a promising personalized solution for patients with severe acetabular bone defect.