[Patellar instability]. / Femoropatellare Instabilität.

We report a retrospective study of patients with patellar instability, all treated by operation and followed up for 3 years. Patients with recurrent dislocation of the patella, lateral displacement and primary patella dislocation were treated by a Elmslie-Trillat reconstruction combined with a soft tissue intervention. Preoperative and follow-up radiographic evaluation included weight bearing anteroposterior view and merchant view. Evaluation was done using the Insall-Salvati index, sulcus and congruence angle. The operation was performed on 23 patients. The clinical evaluation at follow-up was performed using the Knee-Society- and Tegner-Score. Subjective results of the operation were excellent or good in 22 of the 23 at three years with a redislocation rate of only 1 out of 26. Most patients were able to return to the same level of sporting activity as before the injury. The technique described in this paper tries to correct as much as possible of the abnormal parameters in patellar instability to achieve a dynamic stability of the patella through the full range of motion. The excellent results are presumable explained by the use of the combined technique.