Die kindliche patellaluxation: Anatomie, pathomorphologie und behandlungsstrategien

Traumatic and non-traumatic patellofemoral instability (PFI) in children and adolescents is a complex problem determined by a large number of mechanical and pathomorphological factors which are most important in non-traumatic dislocations. While conservative treatment with a short period of immobilization followed by early passive motion and isometric quadriceps strengthening can be considered for traumatic dislocations without cartilaginous injury, a surgical intervention should be considered in cases of non-traumatic origin. As 90% of cases of PFI are non-traumatic and correlated with skeletal deformities, the rate of recurrent dislocation is reported to be up to 80% after initial conservative treatment. To optimize the clinical results the pathologies causing PFI have to be urgently diagnosed. In addition to skeletal pathomorphologies further risk factors have to be taken into consideration for determining the optimal time for surgery. In the past an unreasonably high number of operative techniques for stabilization were described with not always successful clinical results, however more recent biomechanical and clinical studies have shown that a manageable number of operations is sufficient to stabilize the patella. Refixation and the minimally invasive double-bundle technique for reconstruction of the medial patellofemoral ligament are the main surgical techniques to treat PFI in children as both can be used even when the epiphysial cartilage is still open. Further surgical interventions to correct bone deformities, such as trochleoplasty or osteotomy addressing lower limb deformities should be performed after closure of the epiphysial cartilage, while displacement of the tibial tuberosity and soft tissue interventions have to be seen more critically.