Evidence synthesis of functional and radiographic outcomes of 3D-printed acetabular cups in primary and revision total hip arthroplasty: a systematic review and meta-analysis

Abstract Background Three-dimensional (3D)-printed acetabular cups are designed to enhance porous architecture, biological fixation, and osseointegration in total hip arthroplasty (THA). Whether these features translate into superior functional outcomes compared with conventional cups remains uncertain. This systematic review and meta-analysis quantified observed functional improvement after THA using 3D-printed acetabular cups and evaluated comparative evidence. Methods PubMed, Embase, Web of Science, and Scopus were searched from inception to 21 June 2026 following PRISMA guidance. Eligible studies included adults undergoing primary, complex primary, or revision THA using standard 3D-printed or additively manufactured acetabular cups, with extractable preoperative and postoperative Harris Hip Score (HHS) data and at least 12 months of follow-up. Meta-analysis 1 pooled within-group HHS change, while Meta-analysis 2 pooled direct comparisons of HHS improvement between 3D-printed and conventional cups. Random-effects models with restricted maximum likelihood estimation and Knapp–Hartung adjustment were used. Risk of bias was assessed using ROBINS-I and the JBI Critical Appraisal Checklist according to study design; certainty of evidence was assessed using GRADE. Results Twelve studies comprising 917 hips treated with 3D-printed cups were included. In Meta-analysis 1, pooled within-group HHS improvement was 44.75 points (95% CI 38.73 to 50.77; p < 0.001), with heterogeneity (I 2 = 99.09%) and a wide 95% prediction interval (22.99 to 66.52). Three comparative studies including 197 hips (one primary THA study and two revision THA studies) were included in Meta-analysis 2. The pooled mean difference in HHS improvement was 7.17 points in favour of 3D-printed cups but was not statistically significant (95% CI − 12.04 to 26.39; p = 0.25; I 2 = 96.11%). Among the HHS-eligible studies, radiographic and survivorship findings were generally favourable during short- to mid-term follow-up, although assessment criteria and follow-up duration varied. Certainty of evidence was low or very low. Conclusions THA using 3D-printed acetabular cups was associated with substantial observed HHS improvement. Among the HHS-eligible studies, radiographic and survivorship findings were generally favourable during short- to mid-term follow-up. However, comparative evidence remains limited and is insufficient to establish a functional advantage over conventional cups. Further prospective comparative studies with standardised outcomes and longer follow-up are needed.