A dislocated hip replacement can happen for a number of reasons. It can occur soon after surgery due to a patient over-reaching causing the implant to lever out, or due to poor implant positioning at surgery. Hips can also dislocate due to long-term loosening. The immediate treatment is to put the hip back into place under general anaesthetic.
Following this, the cause for the dislocation is found (this may require further imaging) and revision surgery is planned if the hip remains unstable.
This interesting case shows an image where the hip has dislocated (see arrows). This has been due to loosening of the implant and fracturing of the pelvis.
Revision surgery has been performed to fix the bones, bone graft the pelvis with some metal augmentation, and insertion of a new implant.