Custom 3D-Printed Triflange Implants for Treatment of Severe Acetabular Defects, with and without Pelvic Discontinuity: Early Results of Our First 19 Consecutive Cases

Treatment of massive acetabular defects, both with and without pelvic discontinuity, is challenging. The implants utilized in the surgical procedure need to be stable and integrate with poor host bone stock. In the present study, we describe our experience addressing this challenge. METHODS: We identified all patients who underwent surgical implantation of a custom 3D-printed triflange prosthesis with dual-mobility bearings for the treatment of Paprosky 3B acetabular defects between 2014 and 2020. Operative, functional, and radiographic outcomes were assessed. RESULTS: A total of 19 patients were identified, including 11 women. The mean age was 77 years (range, 53 to 91 years), and 8 patients (42%) had proven or likely pelvic discontinuity. The mean follow-up was 53 months (range, 17 to 88 months; mode, 57 months). The cumulative implant survivorship was 100%. Two patients suffered notable sciatic nerve palsy, with 1 case being recurrent. There were no dislocations or fractures. The mean Oxford Hip Score improved significantly, from a mean of 8.6 (range, 0 to 22) preoperatively to 35 (range, 10 to 48) postoperatively (p < 0.0001). Radiographically, there was excellent correlation between implant position and the preoperative plan (p > 0.05). There were no cases of implant loosening or migration, which suggests that stabilization was achieved even among cases with pelvic discontinuity. CONCLUSIONS: These early results suggest that the use of a custom 3D-printed triflange implant has potential advantages over traditional constructs in the treatment of massive acetabular defects, with and without pelvic discontinuity. Excellent implant survivorship and functional improvement were demonstrated in this challenging patient cohort. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.