A new knee joint is not without its problems. The kneecap can dislocate or even break. And sometimes there can be knee pain long after the operation.
There are many possible causes for these problems. Sometimes, the new parts aren’t lined up properly. For other patients, the muscles, ligaments, and other soft tissues are out of balance.
The kneecap moves up and down over the knee as the leg bends and straightens. This is called patellar tracking. Patellar tracking might change after a knee joint replacement. This happens because of implant wear, muscle weakness, or stretching of the nearby soft tissues.
A new study reports that similar problems can occur because of the joint implant. The design of the implant changes how the patella tracks. It may also cause wear and tear on the kneecap and changes in tissue tension.
New knees with patellar tracking problems are being reported. Some problems don’t happen right away. Doctors are watching for these problems and looking for an implant that won’t cause a patellar tracking problem.