Article Details

Background: Acetabular protrusion following primary dual-mobility total hip arthroplasty (DM-THA) is an exceptionally rare complication. DM constructs, widely adopted to reduce dislocation risk, present specific failure modes including acetabular component migration. Osteoporosis is its primary driver; spinopelvic imbalance acts as a coadjuvant risk factor.

Case Presentation: A 64-year-old woman with osteoporosis and severe scoliosis underwent primary DM-THA for hip fracture. Progressive hip pain developed at two years; radiography confirmed acetabular protrusion beyond the ilioischial line. Revision surgery with an acetabular reconstruction plate restored the hip center of rotation, achieving full pain-free ambulation at two-year follow-up.

Systematic Review: A PRISMA 2020 search identified 27 studies (44,782 procedures). Pooled protrusion incidence was 0.4% (95% CI: 0.2–0.7%). Key risk factors included osteoporosis (OR 3.2), Paprosky ?IIB defect (OR 4.1), and cementless fixation in sclerotic bone (OR 3.8). Revision achieved satisfactory outcomes in 78–94% of cases.

Conclusion: The DM construct protects against dislocation but cannot overcome a severely osteoporotic bone-implant interface. Structured radiographic surveillance and timely revision achieve excellent functional outcomes.

Keywords: Dual-mobility total hip arthroplasty; Acetabular protrusion after arthroplasty; Osteoporosis bone-implant interface failure; Acetabular reconstruction plate fixation; Spinopelvic imbalance hip arthroplasty; Revision acetabular reconstruction surgery; Systematic review dual-mobility outcomes