Constitutionally, it can appear, that due to lacking muscular guidance or as a consequence of former kneecap injuries, the kneecap drifts outwardly from its slide bearing. This is called patellar lateralization (outward drifting of the kneecap) or patellar subluxation. The drifting out oft he slide bearing leads to an increased contact pressure of the kneecap onto the slide bearing, which can damage the joint cartilage and eventually leads to an arthrosis. As a consequence not only pains do appear, but also a distinctive noise behind the kneecap (krepitation).

A therapy can be to minimize the pressure on the kneecap from inside to the outside via a snifting step, which is performed arthroscopically, and to optimize the towing direction again via an accompanying reduction of the capsule on the inside. A precondition for such surgical actions would be the MRT based gathering of certain parameters. Potentially, a wrong twist of the thigh or lower leg or a falsely formed slide bearing of the kneecap can be discovered this way. In order to correct such false positions or false forms bony interventions become necessary. In case of weak, because torn, kneecap retaining straps they have to be stabilized with an endogenous tendon, for example. This way the pressure behind the kneecap is distributed evenly again and the damaged cartilage can recover.