Are Dual-Mobility Interfaces Worth the Risk? The Data on 40mm+ Femoral Heads

A surgeon's data-driven guide to achieving maximum impingement-free range of motion without introducing the risks of mechanically assisted crevice corrosion.

Despite the tremendous success of total hip arthroplasty (THA), dislocation remains a problem where dislocation rates can rise to 25% in the revision setting and up to 10% in the primary setting. Prevention of dislocation remains a challenge as patients with primary THA who experience instability frequently demonstrate acetabular components within the “safe zone.”

Owing to the higher rate of dislocation in the revision setting and even more impactful lack of a specific “safe zone” target, dual-mobility (DM) bearings are often used in these high-risk settings. As per the American Joint Replacement Registry 2019 annual report, DM bearings were used in 16.3% of revision THAs in 2018. In addition, DM bearings are being rapidly adopted in primary uncomplicated THA to provide a perceived factor of safety.