Functional and Safety Outcomes of Third-Generation Zimmer Biomet G7® Dual Mobility Total Hip Arthroplasty in Femoral Neck Fractures: A Retrospective Cohort Study

Background: Femoral neck fractures (FNFs) in the ageing population carry high risks of postoperative dislocation, with traditional total hip arthroplasty (THA) reporting rates up to 10%. Dual mobility THA (DM-THA) may provide enhanced stability, but evidence for third-generation implants like the Zimmer Biomet G7® system remains limited. Methods: This retrospective cohort study evaluated 120 patients (mean age 71.6 years; 74% female) with acute displaced intracapsular FNF treated with DM-THA (2021–2023) using the G7® system. Demographics, surgical details (cemented/uncemented stems), complications, and functional outcomes (Oxford Hip Score (OHS) at one year) were analysed against national benchmarks. Results: Zero dislocations and two peri-prosthetic fracture (0.8%, cemented stem) occurred. Thirty-day mortality was 0.8% (below national averages). Functional recovery was excellent (mean OHS: 41/48; 69% scoring ≥40). Surgical complications were minimal (one deep infection 0.8%). Medical complications (anaemia 6.6%, venous thromboembolism 4.2%) were significantly higher in high ASA groups (III-IV). Radiographs confirmed stable implants without loosening. Conclusions: The G7® DM-THA system demonstrates exceptional stability and safety in FNF patients, with no dislocation risk and low peri-prosthetic fracture rates—even with cemented stems. These outcomes support its use in high-risk populations, though comparative studies with conventional THA are needed.