Modern Treatment of Recurrent Patellofemoral Instability - Combined Medial Patellofemoral Ligament Reconstruction and Tibial Tubercle Transfer.

PURPOSE OF THE STUDY The treatment of recurrent patellofemoral instability has undergone a paradigm change during the last 15 years. Instead of non-anatomical operations, the current concept favors the reconstruction of injured structures and the normalization of the biomechanical environment. Our aim was to briefly summarize the etiology, diagnostic regimen, and therapeutic decision making of this varied patient group and to review our own patients who underwent combined medial patellofemoral ligament reconstrucion and tibial tubercle transfer. MATERIAL AND METHODS Between 2015-2017 we performed combined ligament reconstruction and tubercle transfer for recurrent patellofemoral instability on 10 patients. The patients were examined for the degree of trochlea dysplasia, height of the patella, tibial tubercle trochlear groove distance. Additional intraarticular abnormalities were noted. The patients were assessed preoperatively and at follow-up using the Tegner Activity Scale and the Kujala score. Return to sports was also examined. RESULTS The average age of our patients was 22 years (15-40). We had 6 female patients and 4 male patient. The average followup time was 29 months (12-44). 9 patients had a medializing of the tibial tubercle, whilst one patient had a pure distalization to go along with the medial patellofemoral ligament reconstruction using PEEK tenodesis screws. We had no redislocations up to the last follow-up and patients were able to return to their previous activity level and/or sporting activity. The Kujala score improved from an average preoperative value of 48.9 (32-58) to an average follow-up value of 88.6 (70-97). DISCUSSION The essential steps in the treatment of recurrent patellofemoral instability are a thorough physical examination, appropriate imaging and the individual correction of the uncovered anatomical abnormalities. Neither isolated lateral retinacular release, nor medial capsular reefing can preictably produce satisfactory results. CONCLUSIONS Medial patellofemoral ligament reconstruction with tibial tubercle transfer (medializing and/or distalization) is a reliable surgical technique, that provides long term patellar stabilty in this selected group of young patients. Key words: patellar dislocation, joint instability, ligaments, tendon transfer.