Damage of the medial patellofemoral ligament in connection with traumatic patellar luxation is important to recognize. Repair or reconstruction of this structure prevents the recurrence of patellar luxation. Anatomy of the patellofemoral joint, on the other hand, has significant effect on patellar stability, whereby the same procedure is not appropriate for everybody. Some patients with traumatic patellar luxation will benefit from early-stage surgical treatment, some heal equally well by conservative treatment. Previous problems of the treatment of patellar luxation, i.e. poorly predictable recovery and relatively poor results of the surgery, have turned into challenges in the selection of individual therapy and timing of surgery.