[Combined operation involving tibial tubercle distalization for recurrent patellar dislocation with patella alta].

Objective: To explore the clinical effects of combined operation involving tibial tubercle distalization for the recurrent patellar dislocation with patella alta.

Methods: Between April 2010 and May 2016, 14 cases of recurrent patellar dislocation with patella alta were treated with combined operation involving tibial tubercle distalization. There were 5 males and 9 females with an average age of 18.5 years (range, 13-26 years). The left knee was involved in 9 cases and the right knee in 5 cases. The patella had dislocated 3.3 times on average (range, 2-5 times). The interval between the first dislocation and admission was 19.7 months on average (range, 4-60 months), and the main symptoms were knee pain and limited knee movement. Preoperative X-ray films, CT, and MRI examinations of knee joint showed that the epiphyseal plate closed in all patients. Of all patients, 3 patients had avulsion fracture of the inner edge of patella, and 2 patients had free body in articular cavity. The tibial tuberosity-trochlear groove (TT-TG) distance, patellar-trochlear-groove distance, Caton-Deschamps index, knee range of motion (ROM), Lysholm score, International Knee Documentation Committee (IKDC) score, Kujala score, and Tegner score were compared pre- and post-operation.

Results: All patients had primary wound healing. All patients were followed up 24-72 months with an average of 34.6 months. X-ray film and CT examination showed that the patellar dislocation was corrected and the osteotomy of the tibial tubercle healed with an average healing time of 3.8 months (range, 3-5 month). At 1 day and 1 year after operation, the TT-TG distance, patellar-trochlear-groove distance, and Caton-Deschamps index showed significant differences when compared with preoperative values ( P <0.05), but there was no significant difference between 1 day and 1 year after operation ( P >0.05). At the 1 year and 2 years after operation, the knee ROM, Lysholm score, IKDC score, Kujala score, and Tegner score showed significant differences when compared with preoperative values ( P <0.05), and there was no significant difference between the 1 year and 2 years after operation ( P >0.05).

Conclusion: Combined operation involving tibial tubercle distalization is a safe and reliable method, which has satisfactory short-term effectiveness for the recurrent patellar dislocation with patella alta.