Canted seating of the Stryker Modular Dual Mobility liner within a Trident hemispherical acetabular shell

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering

Background:

• Total hip arthroplasty (THA) is a common procedure for managing hip fractures.
• Stryker Trident acetabular shells with Modular Dual Mobility (MDM) liners are utilized in THA.
• Accurate acetabular component implantation is critical for long-term success.

Observation:

• A 75-year-old female presented with a left femoral neck fracture, treated with THA.
• Post-operative radiographs revealed canted seating of the MDM metal liner.
• Intraoperative findings confirmed superior seating but inferior canting of the liner.

Findings:

• Revision surgery involved removing and replacing the acetabular liner.
• Post-revision radiographs confirmed complete and accurate seating of the new liner.
• Clinical follow-up at 6 months showed good function with no radiographic abnormalities.

Implications:

• Canted seating is a potential complication associated with MDM metal liners.
• Surgeons must be vigilant for incomplete inferior liner seating, even with apparent superior seating.
• Thorough radiographic assessment and intraoperative evaluation are crucial for detecting and correcting liner malpositioning.