Two-year radiologic assessment of the Trident Peripheral Self-Locking cup using EBRA

Area of Science:

• Orthopedic surgery
• Radiology
• Biomedical engineering

Background:

• The Trident Peripheral Self-Locking cup is a widely used acetabular component in hip arthroplasty.
• Early migration and instability can impact long-term implant survival.
• Understanding factors influencing early cup behavior is crucial for improving patient outcomes.

Purpose of the Study:

• To radiologically assess early migration of the Trident Peripheral Self-Locking cup two years post-implantation.
• To determine if incomplete postoperative seating correlates with early instability.
• To evaluate functional outcomes and revision rates at five years.

Main Methods:

• Retrospective analysis of 30 hip arthroplasty cases using the EBRA (Ensemble de Radiographies Biplan) method.
• Radiographic assessment of cup migration and seating at two years post-surgery.
• Correlation analysis between incomplete seating and migration, and evaluation of Oxford Hip Scores.

Main Results:

• Average total migration was 1.5 mm, with 17 cups showing >1 mm migration and 7 showing >2 mm migration.
• Twenty cups demonstrated incomplete seating postoperatively, but no relationship with migration was found (p = 0.86).
• Oxford Hip Scores significantly improved post-surgery (p = 0.001), independent of migration (p = 0.76).

Conclusions:

• The majority of cups exhibited early radiographic instability, unrelated to incomplete initial seating.
• Five-year functional outcomes appear favorable and are not influenced by migration or initial seating.
• No revisions for aseptic loosening were reported at the five-year follow-up.