Most hip dislocations occur in the first 2-3 months after surgery, however the risk of a hip dislocation is the lowest with the anterior approach. There is another risk of dislocating years later when the plastic starts to wear out, hence recommendations are made for routine follow-up starting 10-12 years after your surgery.
Those who have a revision of a hip replacement are at increased risk of dislocation and may have special precautions to follow after the surgery such as not bending over beyond 90 degrees or laying on their side.