[Simple diagnostics of patellofemoral instability point to tailored treatment].

Three patients presented with patellar instability. On physical examination, the first patient, a 20-year-old male soccer player, reported pain at the medial insertion ofthe medial patellofemoral ligament (MPFL) after a traumatic patella luxation. He was successfully treated by MPFL reconstruction. The second patient, an 18-year-old woman, presented with patellofemoral pain. On physical examination, the patella could be luxated laterally over approximately half of its width. Conventional X-rays showed a crossing sign, indicating trochlear dysplasia. She was treated by trochleaplasty. The last patient, a 15-year-old girl, presented with patellofemoral instability. On physical examination, a patella alta could be palpated. She was advised to undergo tuberositas distalisation after her epiphyseal growth plates had closed. Patients with patellofemoral instability must be distinguished from patients with patellofemoral-pain syndrome. Simple physical examination and conventional X-rays usually suffice to make this distinction. The treatment is tailored to the pathology found.