The news reported that more patients with hip joint replacements are having dislocations. What’s causing this increase?

You’re right about the rising number of hip dislocations after joint replacement. Doctors aren’t sure exactly why this is happening. There are some possible reasons.

First, with new and better equipment and new joint implant designs, more patients qualify for the surgery. This means that patients who were too great a risk 10 years ago can now have the surgery. A greater number of dislocations still occur in this group.

Second, patients no longer stay in the hospital 10 or more days after the operation. The average stay after a total hip replacement is now less than 5 days. This increases the chances of problems occurring.

Third, the implants come in a wide range of sizes and shapes. The new designs may limit motion, eventually leading to dislocation. Placing the implant in the best position is also important. Any imbalance in positioning of the new joint can cause problems.