https://doi.org/10.1177/1120700020919943 HIP International 1–8 © The Author(s) 2020 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1120700020919943 journals.sagepub.com/home/hpi HIP HIP International Background Total hip arthroplasty (THA) is 1 of the most effective pro- cedures in health care. 1 However, acetabular revision sur- gery remains one of the most common reasons for revision. 2,3 The aim of revision hip surgery is to restore the bone stock, normalise the biomechanics and achieve a sta- ble initial fixation of the implant. Implant design and a variety of surface coatings (beaded, fibre mesh, plasma spray, grit-blasted and hydroxyapatite) contribute to implant stability, facilitating osseointegration. Titanium, porous-coated and highly porous acetabular shells, such as Do trabecular metal cups achieve better results when compared to hemispherical porous titanium cups in acetabular revision surgery? Ana Cruz-Pardos, Eduardo García-Rey, Ricardo Fernandez-Fernández and José Ortega-Chamarro Abstract Background: Trabecular metal (TM) cups were introduced in order to achieve better ingrowth and stability of the cup in acetabular revision surgery. As their use has evolved over time, we have queried whether TM cups would improve results in terms of the rate of aseptic loosening when compared to historical uncemented porous titanium cups used in revision surgery for acetabular bone loss in Hospital La Paz (Madrid, Spain). Methods: We retrospectively reviewed 197 acetabular revisions performed between 1991 and 2015. Titanium cups were used in 81 cases and TM cups in 116. The mean follow-up was 8.1 years (range 1–15); 12.0 ± 7.8 for titanium group and 5.4 ± 3.1 for TM group. The most common reason for revision was aseptic loosening. A Kaplan-Meier analysis was used to determine the survival of the cup, with radiological failure and re-revision due to aseptic loosening as the endpoints. Cox multivariate regression analyses were performed to assess different risk factors for failure. Results: 1 TM cup and 1 titanium cup were re-revised due to aseptic loosening (p = 0.61). Radiological cup loosening was observed in 4 TM cups and 2 titanium cups (p = 1.0). At 6 years, the probability of not having radiological cup loosening was 97.4% (95% CI, 93.9–100) for the titanium cups and 95.1% for the TM cups (95% CI, 90.1–99.9) (p = 0.59). Another 5 cups were re-revised due to dislocation. Hips with a greater Paprosky defect showed a higher risk of loosening (p < 0.05, hazard risk (HR) 3.04; 95% CI, 0.97–9.54). Conclusions: This study shows there was no significant difference in re-revision due to aseptic loosening or radiological loosening between titanium and TM cups in revision surgery for acetabular bone loss. Both types of cups demonstrate excellent results with a low failure rate and minimal complications. Keywords acetabular revision, titanium cups, trabecular cups Date received: 16 September 2019; accepted: 31 January 2020 Orthopaedic Department, Hospital La Paz, Madrid, Spain Corresponding author: Ana Cruz-Pardos, Hospital La Paz, Orthopaedic Department, Paseo de la Castellana 261, Madrid 28046, Spain. Email: ana.cruz@salud.madrid.org 919943HPI 0 0 10.1177/1120700020919943HIP InternationalCruz-Pardos et al. research-article 2020 Original Research Article