High retention rates of custom 3D printed titanium implants in complex pelvic reconstruction, a report on 106 consecutive cases over 10 years

BackgroundAccess to custom 3D printed pelvic implants (3DPI) is improving for application in both arthroplasty revision and tumour reconstruction. There is limited evidence regarding the safety and outcomes of such implants for large bony defects of the pelvis. PurposeTo report the incidence of complications, patient mortality and implant survival following pelvic reconstruction using custom 3Dprinted prostheses in the setting of extensive pelvic bone defects following pelvic tumour resection or failure of total hip arthroplasty (THA) MethodsPatients who underwent reconstruction with a custom 3D printed pelvic prosthesis (3DPI) were identified from our clinical outcomes registry (Complex Reconstruction and Sarcoma Surgical Outcomes Registry; ANZCTRN 12621001421820). Indications for surgery, adverse events, reoperations and rates and modes of failure were recorded. Kaplan-Meier and multistate survival curves were generated for cumulative survival based on indication. ResultsOne hundred and six procedures were completed(RevisionTHA = 33; TumourPelvis = 73) with a median follow up of 4.1 years, ranging from 0.6 to 10 years. Acetabular loosening was the most frequent indication for the RevisionTHA cohort, while indications for tumour varied across primary presentations, metastases and failures of previous resection/reconstruction. Intraoperative complications were observed in 4.1% (95%CI 1.1 - 12.3) of TumourPelvis cases. Overall implant retention was 96% (90 - 99). No mortality events were observed in the RevisionTHA cohort, with 5-year patient survival 79% (70-90) in the TumourPelvis cohort. Procedure-survival free from periprosthetic infection was 86% (74-100) in the RevisionTHA cohort and 85% (76 - 95) in the TumourPelvisCohort. Modelling adverse events using multistate survival models in both cohorts revealed complex time-varying presentation of adverse events, with a significant burden of reoperations and local tumour recurrence in the TumourPelvis cohort. Conclusion3DPIs are a safe and viable option for complex reconstruction of the pelvis across a range of oncological and non-oncological indications. The initial results of the present study provide important information to aid in counselling patients about such procedures and allocating healthcare resources for ongoing care. Further work is required to document functional and biomechanical outcomes in these patient populations.