First of all, more people are having THRs. Good results from the surgery has also increased the number of people and types of problems that can be helped by THR.

Third, with more people having THRs, the number of revision operations is increasing, too. Patients who have had a THR 20 years ago are still alive and going strong. Increased physical activity decreases the life of the implant. Many of these patients have revision surgery to replace the first implant. Fractures are more likely and more common after revision surgery.

Finally, implant design may be a factor. A recent study from Sweden pointed out the fact that implants with a straight and short stem are more likely to loosen causing dislocation and/or fracture. Complications such as fracture and implant loosening may be further reduced with continued research and improved implant design features.