The patellar instability or patellar dislocation is a sliding out of the patella from its physiological “guided groove” in the femur, the so-called trochlea towards outside / lateral. Instability of a patella distinguishes a rare acute from frequent inborn chronic recurrent form which accounts for almost all instabilities.
The frequency of patellar dislocation and age at first dislocation will depend on the degree of underlying bone changes – trochlear dysplasia – and the associated risk factors. As a result, involuntary, uncontrollable patellar dislocations can occur as early as infancy and not only in the vicinity of the knee, but also in the bent position.
Prof. Schoettle has a tremendous amount of knowledge about the factors and relations involved in patellar dislocation and is considered a pioneer in the new and now world-wide school of patellar therapy for trochlear dysplasia, either through MPFL reconstruction or trochleafr surgery, both of which he developed.
Based on our knowledge, in order to treat our patients optimally, we always carry out a comprehensive medical history and an exact examination of all risk factors of patellar dislocation. Based on extensive clinical and biomechanical research, we have developed and published new treatment strategies that have become routine in the treatment of pubic disc joint instability throughout the world. The therapy is then chosen individually, depending on the stage of patella dislocation and the severity of the triggering factors, in order to restore our patients as soon as possible to a stable joint situation.
Since almost all patellar dislocations are caused by a congenital bony problem – trochlear dysplasia – resulting in MPFL insufficiency or rupture, an operative procedure is necessary in most cases, since a patellar dislocation can NOT be controlled or improved muscularly.
On the other hand, intensive training of the wrong musculature can increase the kneecap pressure and cause / increase knee-pat pain.
As mentioned above, a flat or even bulging plain bearing – the trochlear dysplasia – is the decisive risk factor for the patellar instability, since the patella lacks the bony guidance and thus it jumps quite easily from the plain bearing. The most important ligament structure for stabilizing the patellar against the luxating force of the thigh muscle is the so-called “medial patellofemoral ligament” – MPFL – a band between the patella and the inside of the thigh/femur.
If this is not properly applied due to abnormalities or torn in a trochlear dysplasia in the wake of a patellar dislocation, the patella is missing the medializing component and the kneecap can then luxate even easier. In these cases, conservative approaches are unsuccessful and it should be considered after detailed definition of the sources for the instability of the patellar joint, an early surgical procedure. Free cartilage pieces, a significant trochlear dysplasia or gross axis malalignments make an operative procedure inevitable.
Conservative therapy has only rare indications in patellar luxations and instability, namely those with actual accidental instability.
These are composed of physiotherapy with the core area of stabilization training, such as wearing tapes or splints. Specially made insoles can help to improve the symptoms slightly. As far as not yet done, the weight reduction is necessarily effective. At the same time the deep abdominal and back muscles, the hip outer rotators and adductors should be strengthened.