Dual-mobility hip implants cut dislocation risk after surgery, study finds

A newer dual-mobility hip implant cut painful dislocations after surgery in older adults with broken hips, lowering the one-year risk to 1.3% from 4.2% with a standard replacement.

The DUALITY trial enrolled 1,600 people age 65 and older with displaced femoral neck fractures, the break in the upper thigh bone where it meets the hip. Researchers randomized patients at 44 hospitals, 20 in Sweden and 24 in the United Kingdom, to receive either a traditional single ball-and-socket total hip replacement or a dual-mobility cup, which adds a second moving surface to improve stability.

After adjustment for individual risk factors, the odds of dislocation were 70% lower with the dual-mobility implant. Overall surgical complications were also lower, but the study found no difference in infection, death or quality of life during the first year.

Nils Hailer of Uppsala University Hospital called dislocated hip replacements extremely painful and often requiring sedation or another operation to put the joint back in place. People who experience a dislocation may lose confidence in the implant, withdraw from daily activity and become less mobile.

Published in The Lancet, the trial was the largest clinical trial to compare dual-mobility total hip replacement with standard total hip replacement. The fracture type studied accounts for roughly half of all hip fractures globally, and Uppsala University put the number of femoral neck fracture patients worldwide who receive a total hip replacement each year at more than 14 million.

The new implants cost more up front, but the lower complication rate could offset some of that expense over time. No new technology or training is needed, since surgeons already know both implant types.