Are Dual-Mobility Bearings Overused? What a 1,600+ Patient Study Revealed

How maximizing traditional femoral head size achieves excellent hip stability while completely avoiding dual-mobility complications.

Dislocation remains a challenging and relatively common complication following total hip arthroplasty (THA), serving as a leading cause of revision surgery that drives up patient morbidity and health system expenditure. Approved for use in the United States in 2009, dual-mobility (DM) bearings have experienced massive popularity over the last decade. They are rapidly being adopted to provide a perceived factor of safety in primary uncomplicated THAs, accounting for over 10.2% of primary cases in 2020.

The mechanical advantage of a DM design is its large outer bearing diameter, which drastically increases the head-neck ratio and jump distance. However, this dual-articulation layout introduces extra modular interfaces that can trigger unique structural failures. Complications include intra-prosthetic dislocation, accelerated polyethylene wear, increased serum cobalt levels, and malseating of modular liners leading to fretting corrosion and adverse local tissue reactions (ALTR).