Highly porous 3-D printed tritanium acetabular shell for aseptic revision total hip : Arthroplasty: minimum 2-year prospective follow up of 101 implants

Abstract

Aims: To assess the survival, complications, patient-reported outcomes and radiographic integration of the uncemented Trident^® II tritanium acetabular component when used for aseptic revision total hip arthroplasty (rTHA).

Methods: A single-centre prospective cohort study of 101 aseptic rTHA in 100 patients was undertaken. Inclusion criteria were patients suitable for the use of the uncemented acetabular component, aged 18-95 years, willing and able to comply with the study protocol, and provide informed consent. Those with inadequate bone stock to support fixation of the prosthesis were excluded. Functional assessments included the Oxford hip score, Forgotten joint score, EQ-5D, EQ-VAS, pain VAS and satisfaction. Radiographic assessment included acetabular lucent lines and lysis according to Delee and Charnley zones and loosening.

Results: The mean age was 72.5 (standard deviation 11.6) and consisted of 54 females and 46 males. Mean follow-up was 3.1 (range 2 to 4.9) years during which 10 patients died. Indication for rTHA included: loosening of the acetabulum (n = 82), instability (n = 11), broken femoral stem (n = 3), metal on metal with pain and pseudotumour (n = 2), pain (n = 2) and loosening of femoral component (n = 1). There were two re-revisions for deep infection. This resulted in a 1-year all-cause survival of 99.0% (95% CI 97.1 to 100) and 4-year survival of 96.2% (95% CI 90.5 to 100). There was only one case with lucent lines in all three zones and had not osseointegrated, but the component remained stable at 3-years follow-up. All PROMs demonstrated a clinically meaningful improvement, which was significant (p < 0.001) at both 1- and 2-years. Patient satisfaction with their revision THA was 85.6% and 85.3% at 1- and 2-years.

Conclusion: The uncemented highly porous 3-dimensional printed Trident^® II tritanium acetabular component was associated with excellent survivorship, clinically meaningful improvements in PROMs, and high patient satisfaction in the short term when used for aseptic rTHA.

Keywords: 3-D; Arthroplasty; Hip; Outcome; Revision; Survival; Tritanium.