Be careful about where you have the surgery--and who does it. A recent study looked at the results of 59,000 Medicare patients 90 days after surgery. The number of hip replacements done by hospitals and surgeons made a difference in patients' results. Patients were less likely to dislocate the new hip when they had surgery in hospitals that did a lot of hip replacements. Patients whose surgeons did a lot of hip replacements also had fewer dislocations.
There is no "magic number" of surgeries per hospital/surgeon that will guarantee your new hip. The number of complications goes up as the number of surgeries goes down. Happily, dislocations are rare (three percent in one study). Talk with your doctor about the measures you need to take after surgery to protect your new hip.