Socket position determines hip resurfacing 10-year survivorship.

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Medical Device Engineering

Background:

• Modern metal-on-metal hip resurfacing arthroplasty (HRA) has evolved over a decade.
• Early HRA designs faced short-term failures linked to component size, patient factors, and surgical technique.
• A second-generation surgical technique was developed to mitigate early failures, but its long-term impact remains unclear.

Purpose of the Study:

• To determine the long-term survivorship of hips treated with a second-generation HRA cementing technique.
• To identify risk factors associated with HRA failure in patients receiving the improved technique.
• To analyze how dominant risk factors influence specific modes of HRA failure.

Main Methods:

• Retrospective review of 200 hips (178 patients) from the initial cohort using the second-generation technique.
• Assessment of component orientation and contact patch to rim distance.
• Recording of failure modes including fracture, loosening, wear, dislocation, and sepsis, with minimum 25-month follow-up.

Main Results:

• Kaplan-Meier survivorship reached 98.0% at 5 years and 94.3% at 10 years, with 12 hips revised.
• Acetabular component position was the sole variable linked to revision surgery.
• Lower contact patch to rim distance correlated with dislocation, wear, or acetabular loosening.

Conclusions:

• Acetabular component orientation, a surgeon-controlled factor, is critical for long-term hip resurfacing success.
• The second-generation technique has shifted failure modes from aseptic femoral issues to acetabular component wear or loosening.