A new type of hip replacement implant reduces the risk of joint dislocation after surgery by 70%, according to a new study involving 1,600 patients across 44 hospitals in Sweden and the UK, published in The Lancet. The new implant consists of a small ball encased in a much larger plastic ball, which provides better stability.

Each year, more than 14 million patients worldwide suffer a femoral neck fracture. Total hip replacement (THR), in which both the ball and socket of the hip are replaced, is recommended for older, active individuals with a displaced fracture of the femoral neck. While the vast majority regain good mobility and quality of life, up to 8% of these patients experience a dislocation of their hip, a very painful condition in which the artificial joint slips out of place.