A new 3D printing porous trabecular titanium metal acetabular cup for primary total hip arthroplasty: a minimum 2-year follow-up of 92 consecutive patients

Abstract Background Aseptic cup loosening is still one of the main reasons leading to acetabular cup failures. 3D printing porous trabecular titanium metal acetabular cup may provide good initial stability and secondary fixation because of its highly interconnected, porous structure. Few large sample studies have reported the clinical outcomes of Electron Beam Melting (EBM) porous titanium acetabular cup in Chinese population.Methods We retrospectively collected and analyzed the clinical data of a total of 92 consecutive patients between January 2013 and November 2017, with an average follow-up of 48.2±3.6 months. Clinical outcomes included Harris Hip Score (HHS), the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, satisfaction rate and cup survival rate were evaluated. Radiographic assessments were conducted to evaluate osteointegration. Results HHS scores improved significantly while the WOMAC score decreased significantly at the latest follow-up (p<0.001). The satisfaction rate (prevalence of satisfied or very satisfied) was 91.3%. No acetabular cup failures occurred. Radiolucent lines appeared in 15 cases (18 hips), and disappeared in six months. No cup loosening signs found until the last follow up. The overall survival rate of implantation is 99.1% (cup survival rate 100%).Conclusion The new EBM-produced 3D ACT™ cup demonstrated us its favorable short to mid-term clinical outcomes in Chinese THA patients. It can provide high acetabular cup survival rate, great clinical improvements and excellent biological fixation. Further investigations are needed to confirm its long-term outcomes.